U.S. patent application number 16/413152 was filed with the patent office on 2019-08-29 for spacer for a driveshaft assembly.
The applicant listed for this patent is Dana Automotive Systems Group, LLC. Invention is credited to Jeffrey A. Dutkiewicz, Thomas M. O'Neil, Johnny N. Smith.
Application Number | 20190264730 16/413152 |
Document ID | / |
Family ID | 44736023 |
Filed Date | 2019-08-29 |
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United States Patent
Application |
20190264730 |
Kind Code |
A1 |
Dutkiewicz; Jeffrey A. ; et
al. |
August 29, 2019 |
Spacer For A Driveshaft Assembly
Abstract
A driveshaft assembly for use in a vehicle. The driveshaft
assembly has a tubular shaft having a first receiving end portion
with a hollow interior and a driveshaft end having an insert end
portion with a main insert portion, a spacer mounting seat and a
spacer catch surface extending therebetween. The main insert
portion has a diameter greater than a diameter of the spacer
mounting seat. A spacer a first end portion with a first opening, a
center portion with a wall portion, and a second end portion with a
lip portion having a second opening and a transition portion. The
second opening has an inner diameter that is less than an inner
diameter of said first opening. A terminal surface defining the
second opening is disposed radially outboard from the spacer
mounting seat and a portion of the lip portion extends
substantially perpendicular to the wall portion.
Inventors: |
Dutkiewicz; Jeffrey A.;
(Ottawa Hills, OH) ; O'Neil; Thomas M.; (Holland,
OH) ; Smith; Johnny N.; (Toledo, OH) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Dana Automotive Systems Group, LLC |
Maumee |
OH |
US |
|
|
Family ID: |
44736023 |
Appl. No.: |
16/413152 |
Filed: |
May 15, 2019 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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14230856 |
Mar 31, 2014 |
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16413152 |
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13231506 |
Sep 13, 2011 |
8715093 |
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14230856 |
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61403600 |
Sep 17, 2010 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
F16D 1/06 20130101; Y10T
403/7052 20150115; F16D 1/0858 20130101; F16C 3/023 20130101 |
International
Class: |
F16C 3/02 20060101
F16C003/02; F16D 1/08 20060101 F16D001/08 |
Claims
1. A driveshaft assembly, comprising: a tubular shaft having a
first receiving end portion with a hollow interior; a driveshaft
end having an insert end portion with an end surface; wherein said
insert end portion of said driveshaft end has a main insert portion
and a spacer mounting seat; wherein a spacer catch surface extends
between said main insert portion and said spacer mounting seat of
said insert end portion of said driveshaft end; wherein said main
insert portion has a diameter that is greater than a diameter of
said spacer mounting seat; a spacer having a first end portion, a
second end portion and a center portion; wherein at least a portion
of said spacer is interposed between said driveshaft end and said
tubular shaft; wherein said first end portion of said spacer has a
first opening; wherein said center portion of said spacer has a
wall portion, wherein at least a portion of said wall portion of
said center portion of said spacer is disposed radially outboard
from and in direct contact with at least a portion of said main
insert portion of said driveshaft end; wherein said second end
portion of said spacer has a lip portion with a second opening and
a transition portion; wherein said second opening in said lip
portion of said spacer has a first inner diameter that is less than
a second inner diameter of said first opening in said spacer;
wherein at least a portion of a terminal surface defining said
second opening is disposed radially outboard from said spacer
mounting seat of said insert end portion of said driveshaft end;
and wherein at least a portion of said lip portion of said spacer
extends inward toward an interior of said spacer at substantially a
right angle relative to said wall portion of said spacer.
2. The driveshaft assembly of claim 1, wherein said first end
portion of said spacer has a tapered portion.
3. The driveshaft assembly of claim 2, wherein said insert end
portion of said driveshaft end has an insert bevel that is
complementary to said tapered portion of said first end portion of
said spacer.
4. The driveshaft assembly of claim 1, wherein said spacer catch
surface of said insert end portion of said driveshaft end has a
spacer edge surface having a radius of curvature that is
complementary to a radius of curvature of said transition portion
of said first end portion of said spacer.
5. The driveshaft assembly of claim 1, wherein said end surface of
said insert end portion of said driveshaft end is recessed from or
protrudes from said second opening in said first end portion of
said spacer.
6. The driveshaft assembly of claim 1, wherein said spacer is made
of a polymeric material, a plastic material, a metallic material,
cardboard material, wooden material, or fabric material.
7. The driveshaft assembly of claim 1, wherein said spacer is has a
UV-curable urethane coating.
8. The driveshaft assembly of claim 1, wherein said insert end
portion of said driveshaft end has a shaft mounting seat; wherein
at least a portion of said tubular shaft is disposed radially
outboard from said shaft mounting seat of said driveshaft end; and
wherein said shaft mounting seat has a diameter that is greater
than said diameter of said main insert portion and said diameter of
said spacer mounting seat of said driveshaft end.
9. The driveshaft assembly of claim 1, wherein said spacer provides
an interference fit between said driveshaft end and said tubular
shaft.
10. The driveshaft assembly of claim 1, wherein said spacer is an
anti-fretting spacer.
11. The driveshaft assembly of claim 1, wherein a terminus of said
wall portion of said spacer has a thickness that is greater than a
radial dimension said spacer catch surface of said insert end
portion of said driveshaft end.
12. The driveshaft assembly of claim 1, wherein said first
receiving end portion of said tubular shaft has a first terminus
and a second terminus; wherein said first terminus has a thickness
defined by a difference between a first receiving end portion inner
diameter and a first receiving end portion outer diameter; and
wherein said second terminus has a thickness defined by a
difference between said first receiving end portion inner diameter
and an inner diameter of a center portion of said tubular
shaft.
13. The driveshaft assembly of claim 12, wherein said thickness of
said first terminus of said tubular shaft is less than said
thickness of said second terminus of said tubular shaft.
14. A driveshaft assembly, comprising: a tubular shaft having a
first receiving end portion with a hollow interior; a driveshaft
end having an insert end portion with an end surface; wherein said
insert end portion of said driveshaft end has a main insert portion
having a diameter; a spacer having a end portion and a main
portion; wherein at least a portion of said spacer is interposed
between said driveshaft end and said tubular shaft; wherein said
main portion of said spacer has a first opening; wherein said main
portion of said spacer has a wall portion, wherein at least a
portion of said wall portion of said spacer is disposed radially
outboard from and in direct contact with at least a portion of said
main insert portion of said driveshaft end; wherein said end
portion of said spacer has a lip portion with a second opening and
a transition portion; wherein said second opening in said lip
portion of said spacer has a first inner diameter that is less than
a second inner diameter of said first opening in said spacer;
wherein at least a portion of said lip portion of said spacer is in
direct contact with at least a portion of said spacer mounting seat
of said insert end portion of said driveshaft end; and wherein at
least a portion of said lip portion of said spacer extends inward
toward an interior of said spacer at substantially a right angle
relative to said wall portion of said spacer.
15. The driveshaft assembly of claim 14, wherein said end surface
of said driveshaft end has an edge between said edge surface and
said main insert portion of said driveshaft end; wherein said edge
surface of said insert end portion of said driveshaft end has a
radius of curvature that is complementary to a radius of curvature
of said transition portion of said spacer.
16. The driveshaft assembly of claim 14, wherein said spacer is
made of a polymeric material, a plastic material, a metallic
material, cardboard material, wooden material, or fabric
material.
17. The driveshaft assembly of claim 14, wherein said spacer is has
a UV-curable urethane coating.
18. The driveshaft assembly of claim 14, wherein said spacer
provides an interference fit between said driveshaft end and said
tubular shaft.
19. The driveshaft assembly of claim 14, wherein said spacer is an
anti-fretting spacer.
20. The driveshaft assembly of claim 14, wherein said insert end
portion of said driveshaft end has a shaft mounting seat; wherein
at least a portion of said tubular shaft is disposed radially
outboard from said shaft mounting seat of said driveshaft end; and
wherein said shaft mounting seat has a diameter that is greater
than said diameter of said main insert portion of said driveshaft
end.
Description
RELATED APPLICATIONS
[0001] The present application is a continuation application
claiming the benefit to U.S. Provisional Patent Application No.
61/403,600 filed Sep. 17, 2010, U.S. Non-Provisional Patent
Application No. 13/231,506 filed on Sep. 13, 2011 now U.S. Pat. No.
8,715,093 B2, and U.S. Non-Provisional Patent Application No.
14/230,856 filed on Mar. 31, 2014, which are incorporated herein by
reference in their entirety.
FIELD OF THE INVENTION
[0002] The present invention relates to a spacer disposed between
mechanically associated components. More particularly, the present
invention relates to a spacer disposed between rigidly coupled
mechanically associated components, such as those in a driveshaft
assembly.
BACKGROUND OF THE INVENTION
[0003] To reduce fastener use or to militate against positional
deviations, an interference fit is desirable for many components of
machine assemblies. Typically, the interference fit is formed by
joining a slightly oversized male component with a female component
or by joining a slightly undersized female component with a male
component. Particularly, the interference fit is desirable when
joining components of driveshaft assemblies.
[0004] However, depending on the ultimate use of the assembled
components, an interference fit can produce undesirable secondary
effects. For example, the interference fit may cause component
fretting. Fretting results from repeated vibrational or cyclical
stressing of two mechanically associated components. With respect
to driveshaft assemblies in particular, fretting may occur due to
torsional stresses exerted between a shaft and a driveshaft end
component such that slight movements between the shaft and the
driveshaft end component result in fretting. Thus, the more contact
between the two components involved in the interference fit, the
more accurate the alignment between the two components must be if
fretting is to be prevented.
[0005] Further, the undesirable debris produced by the repeated
vibrational or cyclical stressing of an interference fit may result
in unwanted noise during operation. Undesired noise may also be
produced by torsional stresses exerted between metal components
having the interference fit.
[0006] Also, use of an interference fit between components of
driveshaft assemblies can increase production time as a result of
the need to press the components together during manufacturing.
Lastly, as the interference fit is typically between two metallic
components, the components must be sized very accurately, further
increasing a manufacturing cost of the driveshaft assembly.
[0007] The prior art generally discloses the concept of disposing a
spacer between mechanically associated components to try to
overcome some of the aforementioned issues. However, the spacers
disclosed in the prior art are designed to perform different
functions, than the spacer of the present invention. For example,
U.S. Pat. No. 4,530,674 discloses a coupling shaft that includes a
non-metallic bushing disposed between male and female members. The
coupling shafts in this patent are slidably connected and the male
members include crowned surfaces. However, in contrast to the
embodiments of the present invention, the male and female members
of the '674 patent are not rigidly coupled to one another. Thus,
where a bushing is employed in the coupling shaft, the bushing is a
load bearing bushing thus performing a different function than the
spacers of the present invention.
[0008] Similarly, U.S. Pat. No. 4,357,137 discloses a shaft
coupling that includes male and female members and a plastic
insert, where the male member is not rigidly coupled to the female
member and the plastic insert transmits the load from one member to
the other.
[0009] As another example, European Patent Application Publication
No. EP 0 588 468 A2 discloses a component for coupling a keyed
shaft to a keyed sleeve. However, unlike the embodiments of the
present invention, the keyed shaft is not rigidly coupled to the
keyed sleeve. The component, which is preferably formed from a
plastic, bears the transmitted load and also permits some
misalignment of the keyed shaft and the keyed sleeve. The component
may incidentally militate against fretting that may occur when the
keyed shaft and the keyed sleeve are formed from a metal.
[0010] European Patent Application Publication No. EP 0 990 809 A1
discloses a system for coupling rotary shafts that includes a keyed
shaft, a sleeve insert, and a keyed sleeve. The keyed shaft and the
sleeve insert are slidingly disposed in the keyed sleeve and the
sleeve insert is load bearing.
[0011] In addition, the spacers disclosed in the prior art are
structurally different than the spacers of the present invention.
For example, U.S. Patent Application Publication No. 2008/0286039
discloses a yoke bushing for reducing cyclic movement between a
main shaft and a yoke. The yoke is rigidly coupled to the main
shaft and the yoke bushing is disposed therebetween. The yoke
bushing is a flexible structure that equalizes stress fields
between the main shaft and the yoke. All embodiments of the '039
Application place particular emphasis on the upper and lower
portions of the yoke bushing, and the middle portion either does
not contact the main shaft or contains an elastomeric insert,
unlike the present invention which relies on intimate contact
between the central portion of the spacer and the shaft to form the
interference fit.
[0012] As another example, the shaft and sleeve embodied in
European Patent Application Publication No. EP 0 990 809 A1 may be
splined and the sleeve insert may be a split insert. Whereas, the
annular spacer embodied in the present invention have a hollow,
generally tubular shaped body.
[0013] As seen by the above discussion, the spacers of the prior
art are usually between components that are not rigidly coupled.
Such spacers can be load bearing, functional components of the
mechanical assemblies at issue.
[0014] Thus, it would be advantageous to develop a spacer for a
driveshaft assembly that is easy to manufacture and/or install and
will militate against fretting wear between rigidly coupled
mechanically associated components, facilitate assembly, and
militate against undesired operational noise of the driveshaft
assembly.
SUMMARY OF THE INVENTION
[0015] The present invention is directed toward an annular spacer
that maintains an interference fit between a driveshaft end
component and a tubular driveshaft. The annular spacer of the
present invention is easy to manufacture and/or install, militates
against fretting wear between rigidly coupled mechanically
associated components, facilitates assembly, and militates against
undesired operational noise of the driveshaft assembly. The annular
spacer of the present invention eliminates a metal to metal
interference fit between the driveshaft end component and the
tubular driveshaft. As a result of eliminating the metal to metal
interference fit, fretting wear between the driveshaft end
component and the tubular driveshaft is eliminated.
[0016] In accordance with the present invention, a driveshaft
assembly is comprised of: a tubular shaft comprising at least a
first receiving end portion with an opening disposed therein,
wherein the receiving end portion has a receiving end portion inner
diameter, a center portion, wherein the center portion has a center
portion inner diameter, and a hollow interior with a shaft inner
surface; a driveshaft end component comprising an insert end
portion and an attachment end portion; and an annular anti-fretting
spacer comprising a first outer diameter, wherein the first outer
diameter of the spacer is substantially equal to the receiving end
portion inner diameter, a second outer diameter, and an outer
surface, wherein at least a portion of the outer surface is in
contact with the shaft inner surface, wherein the spacer is
disposed on the insert end portion of the driveshaft end component,
wherein the insert end portion of the driveshaft end component,
including the spacer, is disposed within the receiving end portion
of the shaft with an interference fit, and wherein the shaft is
rigidly coupled to the driveshaft end component. In some
embodiments the annular anti-fretting spacer may be composed of a
UV-cured urethane. In some embodiments, the spacer is disposed in
the receiving end portion of the shaft with an interference fit,
wherein the insert end portion of the driveshaft end component is
disposed within the spacer with an interference fit.
[0017] These and other features and advantages of the present
invention will be better understood and its advantages will be more
readily appreciated from the detailed description of the preferred
embodiment, especially when read with reference to the accompanying
drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] The above, as well as other, advantages of the present
invention will become readily apparent to those skilled in the art
from the following detailed description when considered in the
light of the accompanying drawings in which:
[0019] FIG. 1 is a partial, perspective view of an embodiment of an
exploded driveshaft assembly including a spacer according to a
first embodiment of the present invention;
[0020] FIG. 2 is a partial, cross-sectional view of an embodiment
of an assembled driveshaft assembly including a spacer according to
the first embodiment of the present invention;
[0021] FIG. 3 is a partial, cross-sectional view of an embodiment
of an exploded driveshaft assembly including a spacer according to
the first embodiment of the present invention;
[0022] FIG. 4 is a partial, cross-sectional view of an embodiment
of an exploded driveshaft assembly including a spacer according to
another embodiment of the present invention;
[0023] FIG. 5 is a partial, cross-sectional view of an embodiment
of an exploded driveshaft assembly including a spacer according to
yet another embodiment of the present invention;
[0024] FIG. 6 is a partial, cross-sectional view of an embodiment
of an exploded driveshaft assembly including a spacer according to
yet another embodiment of the present invention;
[0025] FIG. 7 is a partial, cross-sectional view of an embodiment
of an exploded driveshaft assembly including a spacer according to
yet another embodiment of the present invention; and
[0026] FIG. 8 is a partial, cross-sectional view of an embodiment
of an exploded driveshaft assembly including a spacer according to
yet another embodiment of the present invention.
[0027] FIG. 9 is a partial, cross-sectional view of an embodiment
of an exploded driveshaft assembly including a spacer according to
yet another embodiment of the present invention.
[0028] FIG. 10 is a partial, cross-sectional view of an embodiment
of an exploded driveshaft assembly including a spacer according to
yet another embodiment of the present invention.
[0029] FIG. 11A is a partial, cross-sectional view of an embodiment
of a tubular driveshaft according to yet another embodiment of the
present invention.
[0030] FIG. 11B is a partial, cross-sectional view of an embodiment
of an assembled spacer and driveshaft end component according to
yet another embodiment of the present invention.
[0031] FIG. 12 is a partial, cross-sectional view of an embodiment
of an assembled driveshaft assembly including a spacer according to
yet another embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0032] It is to be understood that the invention may assume various
alternative orientations and step sequences, except where expressly
specified to the contrary. It is also to be understood that the
specific devices and processes illustrated in the attached
drawings, and described in the following specification are simply
exemplary embodiments of the inventive concepts defined in the
appended claims. Hence, specific dimensions, directions or other
physical characteristics relating to the embodiments disclosed are
not to be considered as limiting, unless expressly stated
otherwise.
[0033] FIGS. 1 through 3 illustrate different views of a driveshaft
assembly according to an embodiment of the present invention. While
the figures depict a driveshaft assembly, it can be readily
appreciated that the invention can be applied to other assemblies
where two or more parts are rigidly joined together. The driveshaft
assembly is merely one exemplary embodiment. The driveshaft
assembly 100 is assembled along a longitudinal axis 102.
[0034] The driveshaft assembly 100 includes a shaft 104, an annular
spacer 106, and a driveshaft end component 108. As shown, the
spacer 106 is disposed between a first receiving end portion 110 of
the shaft 104 and a first driveshaft end component 108, but it is
understood the spacer 106 may be disposed between a second
receiving end portion (not shown) of the shaft 104 and a second
driveshaft end component (not shown).
[0035] The shaft 104 is a tubular, elongate body comprising the
first receiving end portion 110, the second receiving end portion
(not shown), and a center shaft portion 112 (shown in part),
wherein the center shaft portion 112 is bounded by the first 110
and second (not shown) receiving end portions. As shown in FIG. 3,
the shaft 104 may be hollow, with a shaft inner surface 114 and a
hollow interior 116 extending along and through the shaft 104. The
center shaft portion 112 of shaft 104 may have a center shaft
portion inner diameter 118 that is substantially the same as a
receiving end portion inner diameter 120 of either or both of the
first 110 or second (not shown) receiving end portions.
Alternatively, the center portion 112 of shaft 104 may have a
center shaft portion inner diameter 118 that differs from a
receiving end portion inner diameter 120 of either or both of the
first 110 or second (not shown) receiving end portions.
[0036] The first receiving end portion 110 comprises at least (i) a
terminus 122 of wall 124 of the shaft 104 and (ii) an opening 126
to hollow interior 116, wherein the terminus 122 has a thickness
128 defined by the difference between the receiving end portion
inner diameter 120 and a receiving end portion outer diameter
130.
[0037] The shaft 104 may be formed by extrusion, but other
processes such as roll forming, tube milling, or machining may be
used. The shaft 104 may be formed from aluminum, a steel, or any
other metal. The shaft 104 may also be a composite shaft. A
composite shaft is comprised of, for example, a non-metallic center
portion, a metallic first distal end portion, and a metallic second
distal end portion. The non-metallic center portion may be formed
from carbon fiber.
[0038] The annular spacer 106 is a hollow, generally ring shaped
body, with a first inner diameter 132, a second inner diameter 134,
and at least a first outer diameter 136 and second outer diameter
138, wherein the second outer diameter 138 may be substantially the
same as the second inner diameter 134. The spacer 106 also
comprises an outer surface 140, an inner surface 142, an interior
144, a wall 146 interposed between the outer 140 and inner 142
surfaces and a terminal surface 148. The spacer 106 also comprises
a first end portion 150, a second end portion 152, and a center
portion 154, wherein the center portion 154 is bounded by the first
150 and second 152 end portions.
[0039] A first opening 156 is disposed within the first end portion
150. The first end portion 150 may further comprise a tapered
portion 158. The second end portion 152 comprises a lip portion 160
and a transition portion 162. The second end portion 152 is formed
with the wall 146 of the spacer 106 bent in an arcuate fashion
toward the interior 144 of the spacer 106. This arcuate bend in the
wall 146 forms the transition portion 162 and has a radius of
curvature Ci. The portion of the wall 146 that points to the
interior 144 of the spacer 106 forms the lip portion 160. The lip
portion 160 is unitary with the spacer 106 and may be substantially
at a right angle to the center portion 154 of the spacer 106.
[0040] The wall 146 of the spacer 106 may increase in thickness
along the longitudinal axis 102 in the direction from the first
opening 156 of the spacer 106 towards the center portion 154 of the
spacer 106, thus forming the tapered portion 158. The wall 146 of
the spacer, disregarding the tapered portion 158, may have a
minimum thickness of 0.0003 inches.
[0041] For the purposes of the instant description, the outer
surface 140 may be further categorized as 140A, 140B, 140C, or
140D, depending on where along the spacer 106 the outer surface 140
is geographically. To elaborate: 140A designates the outer surface
140 at the tapered portion 158; 140B designates the outer surface
140 at the center portion 154; 140C designates the outer surface
140 at the transition portion 162; and 140D designates the outer
surface 140 at the lip portion 160. A reference to the outer
surface 140 without the use of a letter is meant to indicate the
outer surface 140 in total, or any portion thereof, without regard
to geographic location along the spacer 106.
[0042] Likewise, for the purposes of the instant description, the
inner surface 142 may be further categorized as 142A, 142B, or
142C, depending on where along the spacer 106 the inner surface 142
is geographically. To elaborate: 142A designates the inner surface
142 at the tapered 158 and center 154 portions; 142B designates the
inner surface 142 at the transition portion 162; and 142C
designates the inner surface 142 at the lip portion 160. A
reference to the inner surface 142 without the use of a letter is
meant to indicate the inner surface 142 in total or any portion
thereof, without regard to geographic location along the spacer
106.
[0043] The spacer 106 may be formed from a polymeric material, or
from any other material, such as plastic, metal, paper, cardboard,
wood, paint, or fabric. The spacer 106 may be formed by injection
molding. The spacer 106 may be formed from any other process, such
as heat shrinking, where, the spacer is loosely disposed on at
least a portion of the driveshaft end component 108 and heated,
causing the polymeric heat-shrink material to contract around at
least a portion of the driveshaft end component 108. Alternatively,
the spacer may comprise a pliable substrate wrapped around at least
a portion of the driveshaft end component 108. Further, the spacer
may comprise a coating applied to at least a portion of the
driveshaft end component 108, or as shown in FIG. 11A, the coating
may be applied to the inner surface 114 of the receiving end
portion 110. The spacer may comprise a UV-cured urethane coating on
at least a portion of the driveshaft end component 108 or the inner
surface 114 of the receiving end portion 110. Generally, the
UV-cured urethane coating would be sprayed onto the desired
component of the driveshaft assembly 100 and subsequently cured
with UV light.
[0044] The driveshaft end component 108 is a rigid body comprising
an insert end portion 164 in axial alignment with an attachment end
portion 166 (shown in part). The driveshaft end component 108 may
be formed by machining a blank, forging, or casting. The driveshaft
end component 108 may be formed from a metal such as aluminum or
steel. As shown, the driveshaft end component 108 is a unitary
body, but it may be formed from a plurality of coupled
components.
[0045] The insert end portion 164 comprises an end surface 168, a
spacer mounting seat 170, a spacer catch surface 172, a spacer edge
174, a main insert portion 176, a shaft mounting seat 178, and a
shaft catch surface 180, all in axial alignment with one
another.
[0046] The spacer mounting seat 170 is an annular protrusion from
the main insert portion 176. As shown, the spacer mounting seat 170
has a diameter 182 that is constant; however, the spacer mounting
seat 170 may be tapered. Further, the spacer mounting seat 170 may
include features or be sized to facilitate disposal of the spacer
106 on the driveshaft end component 108.
[0047] The spacer catch surface 172 is an annular, generally planar
surface that defines the boundary between the spacer mounting seat
170 and the main insert portion 176. The spacer catch surface 172
preferably lies in a plane substantially transverse to the
longitudinal axis 102 of the assembled driveshaft 100. However, the
spacer catch surface 172 may also extend between the spacer
mounting seat 170 and the main insert portion 176 in ways other
than transverse, such as angled or curvilinear.
[0048] The main insert portion 176 is an annular protrusion from
the shaft mounting seat 178. As shown, the main insert portion 176
is substantially cylindrical and has a diameter 184 that is
constant; however, as suggested in FIGS. 11B and 12, the main
insert portion 176 may be tapered. Further, the main insert portion
176 may include features or be sized to facilitate welding the
shaft 104 to the driveshaft end component 108.
[0049] The spacer edge 174 is formed at the boundary between the
spacer catch surface 172 and the main insert portion 176. The
spacer edge 174 has a radius of curvature C.sub.2.
[0050] The shaft mounting seat 178 is an annular protrusion from
the attachment end portion 166 of the driveshaft end component 108.
As shown, the shaft mounting seat 178 has a diameter 186 that is
constant; however, the shaft mounting seat 178 may be tapered.
Further, the shaft mounting seat 178 may include features or be
sized to facilitate welding the shaft 104 to the driveshaft end
component 108.
[0051] The shaft catch surface 180 is an annular, planar surface
that defines the boundary between the insert end portion 164 and
the attachment end portion 166. The shaft catch surface 180
preferably lies in a plane substantially transverse to the
longitudinal axis 102 of the assembled driveshaft 100. However, the
shaft catch surface 180 may also extend between the shaft mounting
seat 178 and the attachment end portion 166 in ways other than
transverse, such as angled or curvilinear.
[0052] The attachment end portion 166 includes a coupling end (not
shown). The coupling end may comprise a yoke for coupling the
driveshaft end component 108 to a universal joint, a constant
velocity joint, or any other joint. Alternatively, the coupling end
may include a plurality of splines formed thereon, gear teeth
formed thereon, or the coupling end may include any other
fitting.
[0053] The first outer diameter 136 of the spacer 106 is
substantially the same as the receiving end portion inner diameter
120 of the shaft 104, thereby providing for an interference fit
between the spacer 106 and the shaft 104 upon assembly of the
driveshaft 100. Further, the receiving end portion inner diameter
120 of the shaft 104 is substantially the same as the diameter 186
of the shaft mounting seat 178 of the driveshaft end component 108,
thereby by providing for an interference fit between the driveshaft
end component 108 and the shaft 104 upon assembly of the driveshaft
100.
[0054] The first inner diameter 132 of the spacer 106, equal to a
diameter of a second opening 190 to the interior 144 encircled by
the terminal surface 148, is substantially the same as the diameter
182 of the spacer mounting seat 170, thereby providing for an
interference fit between the spacer 106 and the spacer mounting
seat 170.
[0055] The second inner diameter 134 of the spacer 106 is
substantially the same as the diameter 184 of at least a portion of
the main insert portion 176, thereby providing for an interference
fit between the spacer 106 and at least a portion of the main
insert portion 176.
[0056] The thickness 192 of the spacer mounting seat 170, measured
as the distance along the longitudinal axis 102 between the end
surface 168 and the spacer catch surface 172, may be substantially
the same as a length 194 of the terminal surface 148, as measured
along the longitudinal axis 102. However, the thickness 192 of the
spacer mounting seat 170 may be such that the end surface 168 may
be recessed from, or protrude from, the second opening 190 of
spacer 106.
[0057] The spacer catch surface 172 may have a radial dimension
equal to the difference between the diameter 184 of the main insert
portion 176 and the diameter 182 of the spacer mounting seat
170.
[0058] The transition portion 162 has a radius of curvature,
C.sub.1, that is substantially the same as the radius of curvature,
C.sub.2, of the spacer edge 174 formed between the spacer catch
surface 172 and the main insert portion 176. That is, C.sub.1
C.sub.2, thus allowing for substantially continuous contact between
the inner surface 142 of the spacer 106 and at least a portion of
the insert end portion 164 upon assembly of the driveshaft 100.
[0059] Upon assembly, the spacer 106 is disposed on at least a
portion of the insert end portion 164 such that the end surface 168
and spacer mounting seat 170 are disposed within the second opening
190. The inner surface 142C contacts the spacer catch surface 172
and the inner surface 142A contacts the main insert portion 176.
Inner surface 142B contacts spacer edge 174.
[0060] The terminal surface 148 contacts the spacer mounting seat
170, but end surface 168 would be visible through the second
opening 190 and is not in contact with the spacer 106. The end
surface 168 may be flush with the outer surface 140 of the spacer
106 or the end surface 168 may be recessed therefrom or protrude
therefrom. If present, the tapered portion 158 may form a smooth,
stepless transition from the outer surface 140 of the spacer 106 to
the main insert portion 174.
[0061] Further, the shaft 104 sits on the insert end portion 164
such that the shaft mounting seat 178 is disposed within the hollow
interior 116 of the shaft 104, forming an interference fit between
the shaft mounting seat 178 and the shaft inner surface 114. The
terminus 122 of the wall 128 of the shaft 104 contacts the shaft
catch surface 180. At least a portion of the outer surface 140 of
the spacer 106 contacts the inner surface 114 of the shaft 104,
forming an interference fit between the spacer 106 and the inner
surface 114 of the shaft 104. Preferably, the portion of the outer
surface 140 of the spacer 106 that contacts the shaft inner surface
114 of the shaft 104 is the outer surface 140B at the center
portion 154 of the spacer 106.
[0062] When the driveshaft assembly 100 is completed, the first
receiving end portion 110 is coupled to the driveshaft end
component 108 at the first receiving end portion 110 by a weld. The
first receiving end portion 110 may be coupled to the driveshaft
end component 108 by a magnetic pulse weld, a butt weld formed
therebetween, an arc seam weld formed through the shaft 104, or by
any other method of welding. Alternately, a plurality of fasteners
(not shown) may be used to couple the first receiving end portion
110 to the driveshaft end component 108. When the plurality of
fasteners is used to couple the first receiving end portion 110 to
the driveshaft end component 108, the first receiving end portion
110 may include a mounting flange (not shown) for receiving the
plurality of fasteners.
[0063] FIG. 4 illustrates a driveshaft assembly according to an
embodiment of the present invention. While the figures depict a
driveshaft assembly, it can be readily appreciated that the
invention can be applied to other assemblies where two or more
parts are rigidly joined together. The driveshaft assembly is
merely one exemplary embodiment.
[0064] The driveshaft assembly 200 is assembled along a
longitudinal axis 202. The driveshaft assembly 200 includes a shaft
204, an annular spacer 206, and a driveshaft end component 208. As
shown, the spacer 206 is disposed between a first receiving end
portion 210 of the shaft 204 and a first driveshaft end component
208, but it is understood the spacer 206 may be disposed between a
second receiving end portion (not shown) of the shaft 204 and a
second driveshaft end component (not shown).
[0065] The shaft 204 is a tubular, elongate body comprising the
first receiving end portion 210, the second receiving end portion
(not shown), and a center shaft portion 212 (shown in part),
wherein the center shaft portion 212 is bounded by the first 210
and second (not shown) receiving end portions. As shown in FIG. 4,
the shaft 204 may be hollow, with an inner surface 214 and a hollow
interior 216 extending along and through the shaft 204. The center
shaft portion 212 of shaft 204 may have a center shaft portion
inner diameter 218 that is substantially the same as a receiving
end portion inner diameter 220 of either or both of the first 210
or second (not shown) receiving end portions. Alternatively, the
center portion 212 of shaft 204 may have a center shaft portion
inner diameter 218 that differs from a receiving end portion inner
diameter 220 of either or both of the first 210 or second (not
shown) receiving end portions.
[0066] The first receiving end portion 210 comprises at least (i) a
terminus 222 of wall 224 of the shaft 204 and (ii) an opening 226
to hollow interior 216, wherein the terminus 222 has a thickness
228 defined by the difference between the receiving end portion
inner diameter 220 and the receiving end portion outer diameter
230.
[0067] The shaft 204 may be formed by extrusion, but other
processes such as roll forming, tube milling, or machining may be
used. The shaft 204 may be formed from aluminum, a steel, or any
other metal. The shaft 204 may also be a composite shaft. A
composite shaft is comprised of, for example, a non-metallic center
portion, a metallic first distal end portion, and a metallic second
distal end portion. The non-metallic center portion may be formed
from carbon fiber.
[0068] The annular spacer 206 is a hollow, generally tubular shaped
body, with a first inner diameter 232, a second inner diameter 234,
and at least a first outer diameter 236 and second outer diameter
238. Although not shown in this figure, the second outer diameter
238 may be substantially the same as the second inner diameter 234.
The spacer 206 also comprises an outer surface 240, an inner
surface 242, an interior 244, a wall 246 interposed between the
outer 240 and inner 242 surfaces, and a terminal surface 248. The
spacer 206 also comprises a main portion 250, with a first opening
252 to the interior 244 disposed therein, and an end portion 254,
with a second opening 256 to the interior 244 disposed therein.
[0069] The main portion 250 may further comprise a tapered portion
(not shown). The end portion 254 comprises a lip portion 258 and a
transition portion 260. The end portion 254 is formed with the wall
246 of the spacer 206 bent in an arcuate fashion toward the
interior 244 of the spacer 206. This arcuate bend in the wall 246
forms the transition portion 260 and has a radius of curvature
C.sub.i. The portion of the wall 246 that points to the interior
244 of the spacer 206 forms the lip portion 258. The lip portion
258 is unitary with the spacer 206 and may be substantially at a
right angle to the main portion 250 of the spacer 206. The wall 246
of the spacer 206 may increase in thickness along the longitudinal
axis 202 in the direction from the first opening 252 of the spacer
206 towards the end portion 254 of the spacer 206, thus forming a
tapered portion (not shown). The wall 246 of the spacer,
disregarding any taper, may have a minimum thickness of 0.0003
inches.
[0070] For the purposes of the instant description, the outer
surface 240 may be further categorized as 240A, 240B, or 240C,
depending on where along the spacer 206 the outer surface 240 is
geographically. To elaborate: 240A designates the outer surface 240
at the main portion 250; 240B designates the outer surface 240 at
the transition portion 260; and 240C designates the outer surface
240 at the lip portion 258. A reference to the outer surface 240
without the use of a letter is meant to indicate the outer surface
240 in total, or any portion thereof, without regard to geographic
location along the spacer 206.
[0071] Likewise, for the purposes of the instant description, the
inner surface 242 may be further categorized as 242A, 242B, or
242C, depending on where along the spacer 206 the inner surface 242
is geographically. To elaborate: 242A designates the inner surface
242 at main portion 250; 242B designates the inner surface 242 at
the transition portion 260; and 242C designates the inner surface
242 at the lip portion 258. A reference to the inner surface 242
without the use of a letter is meant to indicate the inner surface
242 in total, or any portion thereof, without regard to geographic
location along the spacer 206.
[0072] The spacer 206 may be formed from a polymeric material, or
from any other material, such as plastic, metal, paper, cardboard,
wood, paint, or fabric. The spacer 206 may be formed by injection
molding. The spacer 206 may be formed from any other process, such
as heat shrinking, where, the spacer is loosely disposed on at
least a portion of the driveshaft end component 208 and heated,
causing the polymeric heat-shrink material to contract around at
least a portion of the driveshaft end component 208. Alternatively,
the spacer may comprise a pliable substrate wrapped around at least
a portion of the driveshaft end component 208. Further, the spacer
may comprise a coating applied to at least a portion of the
driveshaft end component 208, or as shown in FIG. 11A, the coating
may be applied to the inner surface 214 of the receiving end
portion 210. The spacer may comprise a UV-cured urethane coating on
at least a portion of the driveshaft end component 208 or the inner
surface 214 of the receiving end portion 210. Generally, the
UV-cured urethane coating would be sprayed onto the desired
component of the driveshaft assembly 200 and subsequently cured
with UV light.
[0073] The driveshaft end component 208 is a rigid body comprising
an insert end portion 262 in axial alignment with an attachment end
portion 264 (shown in part). The driveshaft end component 208 may
be formed by machining a blank, forging, or casting. The driveshaft
end component 208 may be formed from a metal such as aluminum or
steel. As shown, the driveshaft end component 208 is a unitary
body, but it may be formed from a plurality of coupled
components.
[0074] The insert end portion 262 comprises an end surface 266, an
edge 268, a main insert portion 270, a shaft mounting seat 272, and
a shaft catch surface 274, all in axial alignment with one
another.
[0075] The edge 268 is formed at the boundary between the end
surface 266 and the main insert portion 270. The edge 268 has a
radius of curvature C.sub.2.
[0076] The main insert portion 270 is an annular protrusion from
the shaft mounting seat 272. As shown, the main insert portion 270
is substantially cylindrical and has a diameter 276 that is
constant; however, as suggested in FIGS. 11B and 12, the main
insert portion 270 may be tapered. Further, the main insert portion
270 may include features or be sized to facilitate welding the
shaft 204 to the driveshaft end component 208.
[0077] The shaft mounting seat 272 is an annular protrusion from
the attachment end portion 264 of the driveshaft end component 208.
As shown, the shaft mounting seat 272 has a diameter 278 that is
constant; however, the shaft mounting seat 272 may be tapered.
Further, the shaft mounting seat 272 may include features or be
sized to facilitate welding the shaft 204 to the driveshaft end
component 208.
[0078] The shaft catch surface 274 is an annular, planar surface
that defines the boundary between the insert end portion 262 and
the attachment end portion 264. The shaft catch surface 274
preferably lies in a plane substantially transverse to the
longitudinal axis 202 of the assembled driveshaft 200. However, the
shaft catch surface 274 may also extend between the shaft mounting
seat 272 and the attachment end portion 264 in ways other than
transverse, such as angled or curvilinear.
[0079] The attachment end portion 264 includes a coupling end (not
shown). The coupling end may comprise a yoke for coupling the
driveshaft end component 208 to a universal joint, a constant
velocity joint, or any other joint. Alternatively, the coupling end
may include a plurality of splines formed thereon, gear teeth
formed thereon, or the coupling end may include any other
fitting.
[0080] The first outer diameter 236 of the spacer 206 is
substantially the same as the receiving end portion inner diameter
220 of the shaft 204, thereby providing for an interference fit
between the spacer 206 and the shaft 204 upon assembly of the
driveshaft 200. Further, the receiving end portion inner diameter
220 of the shaft 204 is substantially the same as the diameter 278
of the shaft mounting seat 272 of the driveshaft end component 208,
thereby by providing for an interference fit between the driveshaft
end component 208 and the shaft 204 upon assembly of the driveshaft
200.
[0081] The first inner diameter 232 of the spacer 206, equal to a
diameter of the second opening 256 encircled by the terminal
surface 248, is less than the diameter 276 of the main insert
portion 270.
[0082] The second inner diameter 234 of the spacer 206 is
substantially the same as the diameter 276 of at least a portion of
the main insert portion 270, thereby providing for an interference
fit between the spacer 206 and at least a portion of the main
insert portion 270.
[0083] The transition portion 260 has a radius of curvature,
C.sub.1, that is substantially the same as the radius of curvature,
C.sub.2, of the edge 268 formed between the end surface 266 and the
main insert portion 270. That is, C.sub.1 C.sub.2, thus allowing
for substantially continuous contact between the inner surface 242
of the spacer 206 and at least a portion of the main insert portion
270 upon assembly of the driveshaft 200.
[0084] Upon assembly, the spacer 206 sits on at least a portion of
the main insert portion 270 such that at least a first portion of
the end surface 266 is visible through the second opening 256 and
at least a second portion of the end surface 266 is in contact with
the inner surface 242C. The inner surface 242A contacts at least a
portion of the main insert portion 270 and inner surface 242B
contacts edge 268.
[0085] The terminal surface 248 is not in contact with the main
insert portion 270. If present, any tapered portion (not shown) may
form a smooth, stepless transition from the outer surface 240 of
the spacer 206 to the main insert portion 270.
[0086] Further, the shaft 204 sits on the insert end portion 262
such that the shaft mounting seat 272 is disposed within the hollow
interior 216, forming an interference fit between the shaft
mounting seat 272 and the inner surface 214 of the shaft 204. The
terminus 222 of the wall 224 of the shaft 204 contacts the shaft
catch surface 274. At least a portion of the outer surface 240 of
the spacer 206 contacts the inner surface 214 of the shaft 204,
forming an interference fit between the spacer 206 and the inner
surface 214 of the shaft 204. Preferably, the portion of the outer
surface 240 of the spacer 206 that contacts the inner surface 214
of the shaft 204 is the outer surface 240A at the main portion 250
of the spacer 206.
[0087] When the driveshaft assembly 200 is completed, the first
receiving end portion 210 is coupled to the driveshaft end
component 208 at the first receiving end portion 210 by a weld. The
first receiving end portion 210 may be coupled to the driveshaft
end component 208 by a magnetic pulse weld, a butt weld formed
therebetween, an arc seam weld formed through the shaft 204, or by
any other method of welding. Alternately, a plurality of fasteners
(not shown) may be used to couple the first receiving end portion
210 to the driveshaft end component 208. When the plurality of
fasteners is used to couple the first receiving end portion 210 to
the driveshaft end component 208, the first receiving end portion
210 may include a mounting flange (not shown) for receiving the
plurality of fasteners.
[0088] FIG. 5 illustrates a driveshaft assembly according to an
embodiment of the present invention. While the figures depict a
driveshaft assembly, it can be readily appreciated that the
invention can be applied to other assemblies where two or more
parts are rigidly joined together. The driveshaft assembly is
merely one exemplary embodiment.
[0089] The driveshaft assembly 300 is assembled along a
longitudinal axis 302. The driveshaft assembly 300 includes a shaft
304, an annular spacer 306, and a driveshaft end component 308. As
shown, the spacer 306 is disposed between a first receiving end
portion 310 of the shaft 304 and a first driveshaft end component
308, but it is understood the spacer 306 may be disposed between a
second receiving end portion (not shown) of the shaft 304 and a
second driveshaft end component (not shown).
[0090] The shaft 304 is a tubular, elongate body comprising the
first receiving end portion 310, the second receiving end portion
(not shown), and a center shaft portion 312 (shown in part),
wherein the center shaft portion 312 is bounded by the first 310
and second (not shown) receiving end portions. As shown in FIG. 5,
the shaft 304 may be hollow, with an inner surface 314 and a hollow
interior 316 extending along and through the shaft 304. The center
shaft portion 312 of shaft 304 may have a center shaft portion
inner diameter 318 that is substantially the same as a receiving
end portion inner diameter 320 of either or both of the first 310
or second (not shown) receiving end portions. Alternatively, the
center portion 312 of shaft 304 may have a center shaft portion
inner diameter 318 that differs a receiving end portion inner
diameter 320 of either or both of the first 310 or second (not
shown) receiving end portions.
[0091] The first receiving end portion 310 comprises at least (i) a
terminus 322 of wall 324 of the shaft 304 and (ii) an opening 326
to hollow interior 316, wherein the terminus 322 has a thickness
328 defined by the difference between the receiving end portion
inner diameter 320 and the receiving end portion outer diameter
330.
[0092] The shaft 304 may be formed by extrusion, but other
processes such as roll forming, tube milling, or machining may be
used. The shaft 304 may be formed from aluminum, a steel, or any
other metal. The shaft 304 may also be a composite shaft. A
composite shaft is comprised of, for example, a non-metallic center
portion, a metallic first distal end portion, and a metallic second
distal end portion. The non-metallic center portion may be formed
from carbon fiber.
[0093] The annular spacer 306 is a hollow, generally tubular shaped
body, with an inner diameter 332 and an outer diameter 334. The
spacer 306 also comprises an outer surface 336, an inner surface
338, an interior (not shown), and a wall 340 interposed between the
outer 336 and inner 338 surfaces, said wall having a terminus 342.
The spacer 306 also comprises a first end portion 344, comprising
the terminus 342 and an opening (not shown) to the interior of the
spacer 306. The spacer 306 also comprises a second end portion
346.
[0094] The second end portion 346 comprises a rounded edge 348 and
an opening (not shown) to the interior of the spacer 306. While not
shown in this figure, the first end portion 344 may further
comprise a tapered portion such that the wall 340 of the spacer 306
may increase in thickness along the longitudinal axis 302 in the
direction from the first end portion 344 of the spacer 306 towards
the second end portion 346 of the spacer 306, thus forming any
tapered portion. The wall 340 of the spacer, disregarding any
tapered portion, may have a minimum thickness of 0.0003 inches.
[0095] The spacer 306 may be formed from a polymeric material, or
from any other material, such as plastic, metal, paper, cardboard,
wood, paint, or fabric. The spacer 306 may be formed by injection
molding. The spacer 306 may be formed from any other process, such
as heat shrinking, where, the spacer is loosely disposed on at
least a portion of the driveshaft end component 308 and heated,
causing the polymeric heat-shrink material to contract around at
least a portion of the driveshaft end component 308. Alternatively,
the spacer may comprise a pliable substrate wrapped around at least
a portion of the driveshaft end component 308. Further, the spacer
may comprise a coating applied to at least a portion of the
driveshaft end component 308, or as shown in FIG. 11A, the coating
may be applied to the inner surface 314 of the receiving end
portion 310. The spacer may comprise a UV-cured urethane coating on
at least a portion of the driveshaft end component 308 or the inner
surface 314 of the receiving end portion 310. Generally, the
UV-cured urethane coating would be sprayed onto the desired
component of the driveshaft assembly 300 and subsequently cured
with UV light.
[0096] The driveshaft end component 308 is a rigid body comprising
an insert end portion 350 in axial alignment with an attachment end
portion 352 (shown in part). The driveshaft end component 308 may
be formed by machining a blank, forging, or casting. The driveshaft
end component 308 may be formed from a metal such as aluminum or
steel. As shown, the driveshaft end component 308 is a unitary
body, but it may be formed from a plurality of coupled
components.
[0097] The insert end portion 350 comprises an end surface 354, a
spacer mounting seat 356, a spacer catch surface 358, a main insert
portion 360, and a shaft catch surface 362, all in axial alignment
with one another.
[0098] The spacer mounting seat 356 is an annular protrusion from
the main insert portion 360. As shown, the spacer mounting seat 356
has a diameter 332 that is constant; however, the spacer mounting
seat 356 may be tapered. Further, the spacer mounting seat 356 may
include features or be sized to facilitate disposal of the spacer
306 on the driveshaft end component 308.
[0099] The spacer catch surface 358 is an annular, generally planar
surface that defines the boundary between the spacer mounting seat
356 and the main insert portion 360. The spacer catch surface 358
preferably lies in a plane substantially transverse to the
longitudinal axis 302 of the assembled driveshaft 300. However, the
spacer catch surface 358 may also extend between the spacer
mounting seat 356 and the main insert portion 360 in ways other
than transverse, such as angled or curvilinear.
[0100] The main insert portion 360 is an annular protrusion from
the attachment end portion 352. As shown, the main insert portion
360 is substantially cylindrical and has a diameter 364 that is
constant; however, as suggested in FIGS. 11B and 12, the main
insert portion 360 may be tapered. Further, the main insert portion
360 may include features or be sized to facilitate welding the
shaft 304 to the driveshaft end component 308.
[0101] The shaft catch surface 362 is an annular, planar surface
that defines the boundary between the insert end portion 350 and
the attachment end portion 352. The shaft catch surface 362
preferably lies in a plane substantially transverse to the
longitudinal axis 302 of the assembled driveshaft 300. However, the
shaft catch surface 362 may also extend between the insert end
portion 350 and the attachment end portion 352 in ways other than
transverse, such as angled or curvilinear.
[0102] The attachment end portion 352 includes a coupling end (not
shown). The coupling end may comprise a yoke for coupling the
driveshaft end component 308 to a universal joint, a constant
velocity joint, or any other joint. Alternatively, the coupling end
may include a plurality of splines formed thereon, gear teeth
formed thereon, or the coupling end may include any other
fitting.
[0103] The outer diameter 334 of the spacer 306 is substantially
the same as the receiving end portion inner diameter 320 of the
shaft 304, thereby providing for an interference fit between the
spacer 306 and the shaft 304 upon assembly of the driveshaft
300.
[0104] The inner diameter 332 of the spacer 306 is substantially
the same as the diameter of the spacer mounting seat 356, thereby
providing for an interference fit between the spacer 306 and the
spacer mounting seat 356.
[0105] As show in FIG. 5, the thickness 366 of the spacer mounting
seat 356, measured as the distance along the longitudinal axis 302
between the end surface 354 and the spacer catch surface 358, may
be substantially the same as a length 368 of the spacer 306, as
measured along the longitudinal axis 302. However, the thickness
366 of the spacer mounting seat 356 may be such that the end
surface 354 may protrude from or recess into, the opening (not
shown) of the second end portion 346.
[0106] The spacer catch surface 358 may have a radial dimension 370
equal to the difference between the diameter 364 of the main insert
portion 360 and the diameter 332, equal to the diameter of the of
the spacer mounting seat 356.
[0107] Upon assembly, the spacer 306 sits on at least a portion of
the insert end portion 350 such that spacer mounting seat 356 is
disposed within the spacer 306 and the inner surface 338 contacts
the spacer mounting seat 356.
[0108] The terminus 342 contacts the spacer catch surface 358. The
thickness 372 of the terminus 342 may or may not be equal to the
radial dimension 370 to the spacer catch surface 358. As shown in
FIG. 5, the thickness 372 of the terminus 342 is greater than the
radial dimension 370 of the spacer catch surface 358.
[0109] The end surface 354 would be visible in the opening (not
shown) to the interior (not shown) of the spacer 306, but is not in
contact with the spacer 306. The end surface 354 may be flush with
the outer surface 336 of the spacer 306 or the end surface 354 may
be recessed therefrom or protrude therefrom. If present, any
tapered portion may form a smooth, stepless transition from the
outer surface 336 of the spacer 306 to the main insert portion
360.
[0110] At least a portion of the outer surface 336 of the spacer
306 contacts the inner surface 314 of the shaft 304, forming an
interference fit between the spacer 306 and the inner surface 314
of the shaft 304. When the assembly of the driveshaft is complete,
the shaft 304 is coupled to at least one of: the insert end portion
350 and the attachment end portion 352. In some embodiments, the
shaft 304 may sit on the insert end portion 350 such that the
spacer 306, the spacer mounting seat 356, and the main insert
portion 360 are all disposed within the hollow interior 316 and the
terminus 322 of the wall 324 of the shaft 304 contacts the shaft
catch surface 362.
[0111] When the driveshaft assembly 300 is completed, the first
receiving end portion 310 is coupled to the driveshaft end
component 308 at the first receiving end portion 310 by a weld. The
first receiving end portion 310 may be coupled to the driveshaft
end component 308 by a magnetic pulse weld, a butt weld formed
therebetween, an arc seam weld formed through the shaft 304, or by
any other method of welding. Alternately, a plurality of fasteners
(not shown) may be used to couple the first receiving end portion
310 to the driveshaft end component 308. When the plurality of
fasteners is used to couple the first receiving end portion 310 to
the driveshaft end component 308, the first receiving end portion
310 may include a mounting flange (not shown) for receiving the
plurality of fasteners.
[0112] FIG. 6 illustrates a driveshaft assembly according to an
embodiment of the present invention. While the figures depict a
driveshaft assembly, it can be readily appreciated that the
invention can be applied to other assemblies where two or more
parts are rigidly joined together. The driveshaft assembly is
merely one exemplary embodiment.
[0113] The driveshaft assembly 400 is assembled along a
longitudinal axis 402. The driveshaft assembly 400 includes a shaft
404, an annular spacer 406, and a driveshaft end component 408. As
shown, the spacer 406 is disposed between a first receiving end
portion 410 of the shaft 404 and a first driveshaft end component
408, but it is understood the spacer 406 may be disposed between a
second receiving end portion (not shown) of the shaft 404 and a
second driveshaft end component (not shown).
[0114] The shaft 404 is a tubular, elongate body comprising the
first receiving end portion 410, the second receiving end portion
(not shown), and a center shaft portion 412 (shown in part),
wherein the center shaft portion 412 is bounded by the first 410
and second (not shown) receiving end portions. As shown in FIG. 6,
the shaft 404 may be hollow, with an inner surface 414 and a hollow
interior 416 extending along and through the shaft 404. The center
shaft portion 412 of shaft 404 may have a center shaft portion
inner diameter 418 that is substantially the same as a receiving
end portion inner diameter 420 of either or both of the first 410
or second (not shown) receiving end portions. Alternatively, the
center portion 412 of shaft 404 may have a center shaft portion
inner diameter 418 that differs from a receiving end portion inner
diameter 420 of either or both of the first 410 or second (not
shown) receiving end portions.
[0115] The first receiving end portion 410 comprises at least (i) a
terminus 422 of wall 424 of the shaft 404 and (ii) an opening 426
to hollow interior 416, wherein the terminus 422 has a thickness
428 defined by the difference between the receiving end portion
inner diameter 420 and the receiving end portion outer diameter
430.
[0116] The shaft 404 may be formed by extrusion, but other
processes such as roll forming, tube milling, or machining may be
used. The shaft 404 may be formed from aluminum, a steel, or any
other metal. The shaft 404 may also be a composite shaft. A
composite shaft is comprised of, for example, a non-metallic center
portion, a metallic first distal end portion, and a metallic second
distal end portion. The non-metallic center portion may be formed
from carbon fiber.
[0117] The annular spacer 406 is a hollow, generally tubular shaped
body, with a first inner diameter 432, a second inner diameter 434,
and an outer diameter 438. The spacer 406 also comprises an outer
surface 440, an inner surface 442, an interior 444, a wall 446
interposed between the outer 440 and inner 442 surfaces, and a
terminal surface 448. The spacer 406 also comprises a first end
portion 450, a second end portion 452, and a center portion 454,
wherein the center portion 454 is bounded by the first 450 and
second 452 end portions.
[0118] A first opening 456 is disposed within the first end portion
450. The first end portion 450 may further comprise a tapered
portion 458. The second end portion 452 comprises a lip portion 460
and a transition portion 462. The second end portion 452 is formed
with the wall 446 of the spacer 406 bent in an arcuate fashion
toward the interior 444 of the spacer 406. This arcuate bend in the
wall 446 forms the transition portion 462 and has a radius of
curvature C.sub.1. The portion of the wall 446 that points to the
interior 444 of the spacer 406 forms the lip portion 460. The lip
portion 460 is unitary with the spacer 406 and may be substantially
at a right angle to the center portion 454 of the spacer 406. The
wall 446 of the spacer 406 may increase in thickness along the
longitudinal axis 402 in the direction from the first opening 456
of the spacer 406 towards the center portion 454 of the spacer 406,
thus forming the tapered portion 458. The wall 446 of the spacer,
disregarding the tapered portion 458, may have a minimum thickness
of 0.0003 inches.
[0119] For the purposes of the instant description, the outer
surface 440 may be further categorized as 440A, 440B, or 440C,
depending on where along the spacer 406 the outer surface 440 is
geographically. To elaborate: 440A designates the outer surface 440
at both the tapered 458 and center 454 portions; 440B designates
the outer surface 440 at the transition portion 462; and 440C
designates the outer surface 440 at the lip portion 460. A
reference to the outer surface 440 without the use of a letter is
meant to indicate the outer surface 440 in total, or any portion
thereof, without regard to geographic location along the spacer
406.
[0120] Likewise, for the purposes of the instant description, the
inner surface 442 may be further categorized as 442A, 442B, 442C,
or 442D depending on where along the spacer 406 the inner surface
442 is geographically. To elaborate: 442A designates the inner
surface 442 at the tapered portion 458; 442B designates the inner
surface 442 at the center portion 454; 442C designates the inner
surface 442 at the transition portion 462; and 442D designates the
inner surface 442 at the lip portion 460. A reference to the inner
surface 442 without the use of a letter is meant to indicate the
inner surface 442 in total, or any portion thereof, without regard
to geographic location along the spacer 406.
[0121] The spacer 406 may be formed from a polymeric material, or
from any other material, such as plastic, metal, paper, cardboard,
wood, paint, or fabric. The spacer 406 may be formed by injection
molding. The spacer 406 may be formed from any other process, such
as heat shrinking, where, the spacer is loosely disposed on at
least a portion of the driveshaft end component 408 and heated,
causing the polymeric heat-shrink material to contract around at
least a portion of the driveshaft end component 408. Alternatively,
the spacer may comprise a pliable substrate wrapped around at least
a portion of the driveshaft end component 408. Further, the spacer
may comprise a coating applied to at least a portion of the
driveshaft end component 408, or as shown in FIG. 11A, the coating
may be applied to the inner surface 414 of the receiving end
portion 410. The spacer may comprise a UV-cured urethane coating on
at least a portion of the driveshaft end component 408 or the inner
surface 414 of the receiving end portion 410. Generally, the
UV-cured urethane coating would be sprayed onto the desired
component of the driveshaft assembly 400 and subsequently cured
with UV light.
[0122] The driveshaft end component 408 is a rigid body comprising
an insert end portion 464 in axial alignment with an attachment end
portion 466 (shown in part). The driveshaft end component 408 may
be formed by machining a blank, forging, or casting. The driveshaft
end component 408 may be formed from a metal such as aluminum or
steel. As shown, the driveshaft end component 408 is a unitary
body, but it may be formed from a plurality of coupled
components.
[0123] The insert end portion 464 comprises an end surface 468, a
spacer mounting seat 470, a spacer catch surface 472, an edge 474,
a main insert portion 476, an insert bevel 478, a shaft mounting
seat 480, and a shaft catch surface 482, all in axial alignment
with one another.
[0124] The spacer mounting seat 470 is an annular protrusion from
the main insert portion 476. As shown, the spacer mounting seat 470
has a diameter 484 that is constant; however, the spacer mounting
seat 470 may be tapered.
[0125] The spacer catch surface 472 is an annular, generally planar
surface that defines the boundary between the spacer mounting seat
470 and the main insert portion 476. The spacer catch surface 472
preferably lies in a plane substantially transverse to the
longitudinal axis 402 of the assembled driveshaft 400. However, the
spacer catch surface 472 may also extend between the spacer
mounting seat 470 and the main insert portion 476 in ways other
than transverse, such as angled or curvilinear.
[0126] The main insert portion 476 is an annular protrusion from
the shaft mounting seat 480. As shown, the main insert portion 476
is substantially cylindrical and has a diameter 486 that is
constant; however, the main insert portion 476 may be tapered.
Further, the main insert portion 476 may include features or be
sized to facilitate welding the shaft 404 to the driveshaft end
component 408.
[0127] The edge 474 is formed at the boundary between the spacer
catch surface 472 and the main insert portion 476. The edge 474 has
a radius of curvature C.sub.2.
[0128] As depicted in FIG. 6, the diameter 486 of the main insert
portion 476 has a smaller diameter than the diameter 488 shaft
mounting seat 480 and the insert bevel 478 forms a transition
between the main insert portion 476 and the shaft mounting seat
480.
[0129] The shaft mounting seat 480 is an annular protrusion from
the attachment end portion 466 of the driveshaft end component 408.
As shown, the shaft mounting seat 480 is substantially cylindrical
and has a diameter 488 that is constant; however, as suggested in
FIGS. 11B and 12, the shaft mounting seat 480 may be tapered.
Further, the shaft mounting seat 480 may include features or be
sized to facilitate welding the shaft 404 to the driveshaft end
component 408.
[0130] The shaft catch surface 482 is an annular, planar surface
that defines the boundary between the insert end portion 464 and
the attachment end portion 466. The shaft catch surface 482
preferably lies in a plane substantially transverse to the
longitudinal axis 402 of the assembled driveshaft 400. However, the
shaft catch surface 482 may also extend between the shaft mounting
seat 480 and the attachment end portion 466 in ways other than
transverse, such as angled or curvilinear.
[0131] The attachment end portion 466 includes a coupling end (not
shown). The coupling end may comprise a yoke for coupling the
driveshaft end component 408 to a universal joint, a constant
velocity joint, or any other joint. Alternatively, the coupling end
may include a plurality of splines formed thereon, gear teeth
formed thereon, or the coupling end may include any other
fitting.
[0132] The outer diameter 438 of the spacer 406 is substantially
the same as the receiving end portion inner diameter 420 of the
shaft 404, thereby providing for an interference fit between the
spacer 406 and the shaft 404 upon assembly of the driveshaft 400.
Further, the receiving end portion inner diameter 420 of the shaft
404 may be substantially the same as the diameter 488 of at least a
portion of the shaft mounting seat 480 of the driveshaft end
component 408, thereby by providing for an interference fit between
the driveshaft end component 408 and the shaft 404 upon assembly of
the driveshaft 400.
[0133] The first inner diameter 432 of the spacer 406, equal to a
diameter of a second opening 485 to the interior 444 encircled by
the terminal surface 448, is substantially the same as the diameter
484 of the spacer mounting seat 470, thereby providing for an
interference fit between the spacer 406 and the spacer mounting
seat 470.
[0134] The second inner diameter 434 of the spacer 406 is
substantially the same as the diameter 486 of at least a portion of
the main insert portion 476, thereby providing for an interference
fit between the spacer 406 and at least a portion of the main
insert portion 476.
[0135] The thickness 490 of the spacer mounting seat 470, measured
as the distance along the longitudinal axis 402 between the end
surface 468 and the spacer catch surface 472, may be substantially
the same as a length 492 of the terminal surface 448, as measured
along the longitudinal axis 402. However, the thickness 490 of the
spacer mounting seat 470 may be such that the end surface 468 may
be recessed from, or protrude from, the second opening 485 of
spacer 406.
[0136] The spacer catch surface 472 may have a radial dimension 494
equal to the difference between the diameter 486 of the main insert
portion 476 and the diameter 484 of the spacer mounting seat
470.
[0137] The transition portion 462 has a radius of curvature,
C.sub.1, that is substantially the same as the radius of curvature,
C.sub.2, of the edge 474 formed between the spacer catch surface
472 and the main insert portion 476. That is, C.sub.1 C.sub.2, thus
allowing for substantially continuous contact between the inner
surface 442 of the spacer 406 and at least a portion of the insert
end portion 464 upon assembly of the driveshaft 400.
[0138] Upon assembly, the spacer 406 sits on at least a portion of
the insert end portion 464 such that the end surface 468 and spacer
mounting seat 470 are disposed within the second opening 485. The
inner surface 442A contacts the insert bevel 478. The inner surface
442B contacts at least a portion of the main insert portion 476.
The inner surface 442C contacts edge 474. And, the inner surface
442D contacts the spacer catch surface 472.
[0139] The terminal surface 448 contacts the spacer mounting seat
470, and end surface 468 would be visible through the second
opening 485 and is not in contact with the spacer 406. The end
surface 468 may be flush with the outer surface 440 of the spacer
406 or the end surface 468 may be recessed therefrom or protrude
therefrom. If present, the tapered portion 458 may form a smooth,
stepless transition from the outer surface 440 of the spacer 406 to
the shaft mounting seat 480.
[0140] Further, the shaft 404 sits on the insert end portion 464
such that the shaft mounting seat 480 is disposed within the hollow
interior 416, forming an interference fit between the shaft
mounting seat 480 and the inner surface 414 of the shaft 404. The
terminus 422 of the wall 424 of the shaft 404 contacts the shaft
catch surface 482. At least a portion of the outer surface 440 of
the spacer 406 contacts the inner surface 414 of the shaft 404,
forming an interference fit between the spacer 406 and the inner
surface 414 of the shaft 404. Preferably, the portion of the outer
surface 440 of the spacer 406 that contacts the inner surface 414
of the shaft 404 is the outer surface 440A at the tapered 458 and
center 454 portions of the spacer 406.
[0141] When the driveshaft assembly 400 is completed, the first
receiving end portion 410 is coupled to the driveshaft end
component 408 at the first receiving end portion 410 by a weld. The
first receiving end portion 410 may be coupled to the driveshaft
end component 408 by a magnetic pulse weld, a butt weld formed
therebetween, an arc seam weld formed through the shaft 404, or by
any other method of welding. Alternately, a plurality of fasteners
(not shown) may be used to couple the first receiving end portion
410 to the driveshaft end component 408. When the plurality of
fasteners is used to couple the first receiving end portion 410 to
the driveshaft end component 408, the first receiving end portion
410 may include a mounting flange (not shown) for receiving the
plurality of fasteners.
[0142] FIG. 7 illustrates a driveshaft assembly according to an
embodiment of the present invention. While the figures depict a
driveshaft assembly, it can be readily appreciated that the
invention can be applied to other assemblies where two or more
parts are rigidly joined together. The driveshaft assembly is
merely one exemplary embodiment.
[0143] The driveshaft assembly 500 is assembled along a
longitudinal axis 502. The driveshaft assembly 500 includes a shaft
504, an annular spacer 506, and a driveshaft end component 508. As
shown, the spacer 506 is disposed between a first receiving end
portion 510 of the shaft 504 and a first driveshaft end component
508, but it is understood the spacer 506 may be disposed between a
second receiving end portion (not shown) of the shaft 504 and a
second driveshaft end component (not shown).
[0144] The shaft 504 is a tubular, elongate body comprising the
first receiving end portion 510, the second receiving end portion
(not shown), and a center shaft portion 512 (shown in part),
wherein the center shaft portion 512 is bounded by the first 510
and second (not shown) receiving end portions. As shown in FIG. 7,
the shaft 504 may be hollow, with an inner surface 514 and a hollow
interior 516 extending along and through the shaft 504. The center
shaft portion 512 of shaft 504 may have a center shaft portion
inner diameter 518 that is substantially the same as a receiving
end portion inner diameter 520 of either or both of the first 510
or second (not shown) receiving end portions. Alternatively, the
center portion 512 of shaft 504 may have a center shaft portion
inner diameter 518 that differs from a receiving end portion inner
diameter 520 of either or both of the first 510 or second (not
shown) receiving end portions.
[0145] The first receiving end portion 510 comprises at least (i) a
terminus 522 of wall 524 of the shaft 504 and (ii) an opening 526
to hollow interior 516, wherein the terminus 522 has a thickness
528 defined by the difference between the receiving end portion
inner diameter 520 and the receiving end portion outer diameter
530.
[0146] The shaft 504 may be formed by extrusion, but other
processes such as roll forming, tube milling, or machining may be
used. The shaft 504 may be formed from aluminum, a steel, or any
other metal. The shaft 504 may also be a composite shaft. A
composite shaft is comprised of, for example, a non-metallic center
portion, a metallic first distal end portion, and a metallic second
distal end portion. The non-metallic center portion may be formed
from carbon fiber.
[0147] The annular spacer 506 is a hollow, generally tubular shaped
body, with an inner diameter 532 and an outer diameter 536. The
spacer 506 also comprises an outer surface 538, an inner surface
540, an interior 542, a wall 544 interposed between the outer 538
and inner 540 surfaces, and a terminal surface 546. The spacer 506
also comprises a first end portion 548 and a main portion 550.
[0148] A first opening 552 is disposed within the first end portion
548. The first end portion 548 may further comprise a tapered
portion 554. The wall 544 of the spacer 506 may increase in
thickness along the longitudinal axis 502 in the direction from the
first opening 552 of the spacer 506 towards the main portion 550 of
the spacer 506, thus forming the tapered portion 554. The wall 544
of the spacer, disregarding the tapered portion 554, may have a
minimum thickness of 0.0003 inches.
[0149] For the purposes of the instant description, the inner
surface 540 may be further categorized as 540A or 540B, depending
on where along the spacer 506 the inner surface 540 is
geographically. To elaborate: 540A designates the inner surface 540
at the tapered portion 554 and 540B designates the inner surface
540 at the main portion 550. A reference to the inner surface 540
without the use of a letter is meant to indicate the inner surface
540 in total, or any portion thereof, without regard to geographic
location along the spacer 506.
[0150] The spacer 506 may be formed from a polymeric material, or
from any other material, such as plastic, metal, paper, cardboard,
wood, paint, or fabric. The spacer 506 may be formed by injection
molding. The spacer 506 may be formed from any other process, such
as heat shrinking, where, the spacer is loosely disposed on at
least a portion of the driveshaft end component 508 and heated,
causing the polymeric heat-shrink material to contract around at
least a portion of the driveshaft end component 508. Alternatively,
the spacer may comprise a pliable substrate wrapped around at least
a portion of the driveshaft end component 508. Further, the spacer
may comprise a coating applied to at least a portion of the
driveshaft end component 508, or as shown in FIG. 11A, the coating
may be applied to the inner surface 514 of the receiving end
portion 510. The spacer may comprise a UV-cured urethane coating on
at least a portion of the driveshaft end component 508 or the inner
surface 514 of the receiving end portion 510. Generally, the
UV-cured urethane coating would be sprayed onto the desired
component of the driveshaft assembly 500 and subsequently cured
with UV light.
[0151] The driveshaft end component 508 is a rigid body comprising
an insert end portion 556 in axial alignment with an attachment end
portion 558 (shown in part). The driveshaft end component 508 may
be formed by machining a blank, forging, or casting. The driveshaft
end component 508 may be formed from a metal such as aluminum or
steel. As shown, the driveshaft end component 508 is a unitary
body, but it may be formed from a plurality of coupled
components.
[0152] The insert end portion 556 comprises an end surface 560, a
main insert portion 562, an insert bevel 564, a shaft mounting seat
566, and a shaft catch surface 568, all in axial alignment with one
another.
[0153] The main insert portion 562 may be substantially cylindrical
having a constant diameter of 570, but may also be tapered or
contain other geographical features. The main insert portion 562 is
an annular protrusion from the shaft mounting seat 566.
[0154] As depicted in FIG. 7, the diameter 570 of the main insert
portion 562 has a smaller diameter than a diameter 572 of the shaft
mounting seat 566 and the insert bevel 564 forms a transition
between the main insert portion 562 and the shaft mounting seat
566.
[0155] The shaft mounting seat 566 is an annular protrusion from
the attachment end portion 558 of the driveshaft end component 508.
As shown, the shaft mounting seat 566 is substantially cylindrical
and has a diameter 572 that is substantially constant; however, as,
suggested in FIGS. 11B and 12, the shaft mounting seat 566 may be
tapered. Further, the shaft mounting seat 566 may include features
or be sized to facilitate welding the shaft 504 to the driveshaft
end component 508.
[0156] The shaft catch surface 568 is an annular, planar surface
that defines the boundary between the insert end portion 556 and
the attachment end portion 558. The shaft catch surface 568
preferably lies in a plane substantially transverse to the
longitudinal axis 502 of the assembled driveshaft 500. However, the
shaft catch surface 568 may also extend between the shaft mounting
seat 566 and the attachment end portion 558 in ways other than
transverse, such as angled or curvilinear.
[0157] The attachment end portion 558 includes a coupling end (not
shown). The coupling end may comprise a yoke for coupling the
driveshaft end component 508 to a universal joint, a constant
velocity joint, or any other joint. Alternatively, the coupling end
may include a plurality of splines formed thereon, gear teeth
formed thereon, or the coupling end may include any other
fitting.
[0158] The outer diameter 536 of the spacer 506 is substantially
the same as the receiving end portion inner diameter 520 of the
shaft 504, thereby providing for an interference fit between the
spacer 506 and the shaft 504 upon assembly of the driveshaft 500.
Further, the receiving end portion inner diameter 520 of the shaft
504 is substantially the same as the diameter 572 of the shaft
mounting seat 566 of the driveshaft end component 508, thereby by
providing for an interference fit between the driveshaft end
component 508 and the shaft 504 upon assembly of the driveshaft
500.
[0159] The inner diameter 532 of the spacer 506 is substantially
the same as the diameter 570 of the main insert portion 562,
thereby providing for an interference fit between the spacer 506
and the main insert portion 564.
[0160] Upon assembly, the spacer 506 sits on at least a portion of
the insert end portion 556 such that the end surface 560 and main
insert portion 562 are disposed within the spacer 506. The inner
surface 540A contacts the insert bevel 564 and the inner surface
540B contacts at least a portion of the main insert portion
562.
[0161] The terminal surface 546 does not contact either the
driveshaft end component 508 or the shaft 504. End surface 560
would be visible through a second opening 574 to the interior 542
of the spacer 506 but is not in contact with the spacer 506. The
end surface 560 may be flush with the terminal surface 546 of the
spacer 506 or the end surface 560 may be recessed therefrom or
protrude therefrom. If present, the tapered portion 554 may form a
smooth, stepless transition from the outer surface 538 of the
spacer 506 to the shaft mounting seat 566.
[0162] Further, the shaft 504 sits on the insert end portion 556
such that the shaft mounting seat 566 is disposed within the hollow
interior 516, forming an interference fit between the shaft
mounting seat 566 and the inner surface 514 of the shaft 504. The
terminus 522 of the wall 524 of the shaft 504 contacts the shaft
catch surface 568. At least a portion of the outer surface 538 of
the spacer 506 contacts the inner surface 514 of the shaft 504,
forming an interference fit between the spacer 506 and the inner
surface 514 of the shaft 504.
[0163] When the driveshaft assembly 500 is completed, the first
receiving end portion 510 is coupled to the driveshaft end
component 508 at the first receiving end portion 510 by a weld. The
first receiving end portion 510 may be coupled to the driveshaft
end component 508 by a magnetic pulse weld, a butt weld formed
therebetween, an arc seam weld formed through the shaft 504, or by
any other method of welding. Alternately, a plurality of fasteners
(not shown) may be used to couple the first receiving end portion
510 to the driveshaft end component 508. When the plurality of
fasteners is used to couple the first receiving end portion 510 to
the driveshaft end component 508, the first receiving end portion
510 may include a mounting flange (not shown) for receiving the
plurality of fasteners.
[0164] FIG. 8 illustrates a driveshaft assembly according to an
embodiment of the present invention. While the figures depict a
driveshaft assembly, it can be readily appreciated that the
invention can be applied to other assemblies where two or more
parts are rigidly joined together. The driveshaft assembly is
merely one exemplary embodiment.
[0165] The driveshaft assembly 600 is assembled along a
longitudinal axis 602. The driveshaft assembly 600 includes a shaft
604, an annular spacer 606, and a driveshaft end component 608. As
shown, the spacer 606 is disposed between a first receiving end
portion 610 of the shaft 604 and a first driveshaft end component
608, but it is understood the spacer 606 may be disposed between a
second receiving end portion (not shown) of the shaft 604 and a
second driveshaft end component (not shown).
[0166] The shaft 604 is a tubular, elongate body comprising the
first receiving end portion 610, the second receiving end portion
(not shown), and a center shaft portion 612 (shown in part),
wherein the center shaft portion 612 is bounded by the first 610
and second (not shown) receiving end portions. As shown in FIG. 8,
the shaft 604 may be hollow, with an inner surface 614 and a hollow
interior 616 extending along and through the shaft 604. The center
shaft portion 612 of shaft 604 may have a center shaft portion
inner diameter 618 that is substantially the same as a receiving
end portion inner diameter 620 of either or both of the first 610
or second (not shown) receiving end portions. However, as depicted
in FIG. 8, the center portion 612 of shaft 604 may have a center
shaft portion inner diameter 618 that differs from a receiving end
portion inner diameter 620 of either or both of the first 610 or
second (not shown) receiving end portions. The first 610 or second
(not shown) receiving end portions may be formed by machining the
shaft 604 in a secondary operation, but may also be formed by any
other method.
[0167] The first receiving end portion 610 comprises at least (i) a
first terminus 622 of wall 624, wherein the first terminus 622 has
a thickness 628 defined by the difference between the receiving end
portion inner diameter 620 and the receiving end portion outer
diameter 630, (ii) a second terminus 632, wherein the second
terminus 632 has a thickness 634 defined by the difference between
the receiving end portion inner diameter 620 and the center portion
inner diameter 618, and (iii) an opening 636 to hollow interior
616.
[0168] The shaft 604 may be formed by extrusion, but other
processes such as roll forming, tube milling, or machining may be
used. The shaft 604 may be formed from aluminum, a steel, or any
other metal. The shaft 604 may also be a composite shaft. A
composite shaft is comprised of, for example, a non-metallic center
portion, a metallic first distal end portion, and a metallic second
distal end portion. The non-metallic center portion may be formed
from carbon fiber.
[0169] The annular spacer 606 is a hollow, generally tubular shaped
body, with an inner diameter 638, an outer diameter 640, an outer
surface 642, an inner surface 644, an interior 646, a wall 648
interposed between the outer 642 and inner 644 surfaces, a first
terminal surface 650, and a second terminal surface 652. The wall
648 of spacer 606 may be tapered at the first 650 or second 652
terminal surfaces or at any portion adjacent thereto. The spacer
606 further comprises first 654 and second 656 openings to the
interior 646 of the spacer 606. The wall 648 of the spacer,
disregarding any tapered portion, may have a minimum thickness of
0.0003 inches.
[0170] The spacer 606 may be formed from a polymeric material, or
from any other material, such as plastic, metal, paper, cardboard,
wood, paint, or fabric. The spacer 606 may be formed by injection
molding. The spacer 606 may be formed from any other process, such
as heat shrinking, where, the spacer is loosely disposed on at
least a portion of the driveshaft end component 608 and heated,
causing the polymeric heat-shrink material to contract around at
least a portion of the driveshaft end component 608. Alternatively,
the spacer may comprise a pliable substrate wrapped around at least
a portion of the driveshaft end component 608. Further, the spacer
may comprise a coating applied to at least a portion of the
driveshaft end component 608, or as shown in FIG. 11A, the coating
may be applied to the inner surface 614A of the receiving end
portion 610. The spacer may comprise a UV-cured urethane coating on
at least a portion of the driveshaft end component 608 or the inner
surface 614A of the receiving end portion 610. Generally, the
UV-cured urethane coating would be sprayed onto the desired
component of the driveshaft assembly 600 and subsequently cured
with UV light.
[0171] The driveshaft end component 608 is a rigid body comprising
an insert end portion 658 in axial alignment with an attachment end
portion 660 (shown in part). The driveshaft end component 608 may
be formed by machining a blank, forging, or casting. The driveshaft
end component 608 may be formed from a metal such as aluminum or
steel. As shown, the driveshaft end component 608 is a unitary
body, but it may be formed from a plurality of coupled
components.
[0172] The insert end portion 658 comprises an end surface 662, a
spacer mounting seat 664, a spacer catch surface 666, a shaft
mounting seat 668, and a shaft catch surface 670, all in axial
alignment with one another.
[0173] The spacer mounting seat 664 is an annular protrusion from
the shaft mounting seat 668. As shown, the spacer mounting seat 664
is substantially cylindrical and has a diameter 672 that is
constant; however, as suggested in FIGS. 11B and 12, the spacer
mounting seat 664 may be tapered. Further, the spacer mounting seat
664 may include features or be sized to facilitate welding the
shaft 604 to the driveshaft end component 608.
[0174] The spacer catch surface 666 is an annular, planar surface
that defines the boundary between the spacer mounting seat 664 and
the shaft mounting seat 668. The spacer catch surface 666
preferably lies in a plane substantially transverse to the
longitudinal axis 602 of the assembled driveshaft 600. However, the
spacer catch surface 666 may also extend between the spacer
mounting seat 664 and the shaft mounting seat 668 in ways other
than transverse, such as angled or curvilinear.
[0175] The shaft mounting seat 668 is an annular protrusion from
the attachment end portion 660 of the driveshaft end component 608.
As shown, the shaft mounting seat 668 has a diameter 680 that is
constant; however, the shaft mounting seat 668 may be tapered.
Further, the shaft mounting seat 668 may include features or be
sized to facilitate welding the shaft 604 to the driveshaft end
component 608.
[0176] The shaft catch surface 670 is an annular, planar surface
that defines the boundary between the insert end portion 658 and
the attachment end portion 660. The shaft catch surface 670
preferably lies in a plane substantially transverse to the
longitudinal axis 602 of the assembled driveshaft 600. However, the
shaft catch surface 670 may also extend between the shaft mounting
seat 668 and the attachment end portion 660 in ways other than
transverse, such as angled or curvilinear.
[0177] The attachment end portion 660 includes a coupling end (not
shown). The coupling end may comprise a yoke for coupling the
driveshaft end component 608 to a universal joint, a constant
velocity joint, or any other joint. Alternatively, the coupling end
may include a plurality of splines formed thereon, gear teeth
formed thereon, or the coupling end may include any other
fitting.
[0178] The outer diameter 640 of the spacer 606 is substantially
the same as the receiving end portion inner diameter 620 of the
shaft 604, thereby providing for an interference fit between the
spacer 606 and the shaft 604 upon assembly of the driveshaft
600.
[0179] The inner diameter 638 of the spacer 606 is substantially
the same as the diameter 672 of at least a portion of the spacer
mounting seat 664, thereby providing for an interference fit
between the spacer 606 and at least a portion of the spacer
mounting seat 664.
[0180] The thickness 674 of the spacer mounting seat 664, measured
as the distance along the longitudinal axis 602 between the end
surface 662 and the spacer catch surface 666, may be substantially
the same as a length 676 of the spacer 606, as measured along the
longitudinal axis 602. However, the thickness 674 of the spacer
mounting seat 664 may be such that the end surface 662 may be
recessed from, or protrude from, the second opening 656 of spacer
606. Further, the length 676 of the spacer 606 may be less than the
thickness 674 of the spacer mounting seat 664 such that the first
terminal surface 650 does not contact the spacer catch surface
666.
[0181] The spacer catch surface 666 may have a radial dimension 682
equal to the difference between the diameter 672 of the spacer
mounting seat 664 and the diameter 680 of the shaft mounting seat
668. The radial dimension 682 may or may not be equal to the
difference between the inner 638 and outer 640 diameters of the
spacer 606.
[0182] The shaft catch surface 670 has a radial dimension 684 that
may or may not be equal to the thickness 622 of wall 624 of the
shaft 604.
[0183] Upon assembly, the spacer 606 sits on at least a portion of
the insert end portion 658 such that at least a portion of the
spacer mounting seat 664 is disposed within the spacer 606 and the
inner surface 644 contacts at least a portion of the spacer
mounting seat 664.
[0184] The second terminal surface 652 contacts the second terminus
632. As noted above, the first terminal surface 650 may be in
contact with the spacer catch surface 666. Alternatively, the first
terminal surface 650 may not be in contact with the spacer catch
surface 666. End surface 662 would be visible through the second
opening 656 and is not in contact with the spacer 606. The end
surface 662 may be flush with the second terminal surface 652 of
the spacer 606 or the end surface 662 may be recessed therefrom or
protrude therefrom. If present, any tapered portion may form a
smooth, stepless transition from the spacer 606 to either or both
the shaft 604 or the driveshaft end component 608.
[0185] Further, the shaft 604 may sit on the insert end portion 658
such that the first terminus 622 of the wall 624 of the shaft 604
contacts the shaft catch surface 670. At least a portion of the
outer surface 642 of the spacer 606 contacts the inner surface 614
of the shaft 604, forming an interference fit between the spacer
606 and the inner surface 614 of the shaft 604. Preferably, the
outer surface 642 of the spacer 606 contacts the inner surface 614
at the receiving end portion 610, designated as 614A.
[0186] When the driveshaft assembly 600 is completed, the first
receiving end portion 610 is coupled to the driveshaft end
component 608 at the first receiving end portion 610 by a weld. The
first receiving end portion 610 may be coupled to the driveshaft
end component 608 by a magnetic pulse weld, a butt weld formed
therebetween, an arc seam weld formed through the shaft 604, or by
any other method of welding. Alternately, a plurality of fasteners
(not shown) may be used to couple the first receiving end portion
610 to the driveshaft end component 608. When the plurality of
fasteners is used to couple the first receiving end portion 610 to
the driveshaft end component 608, the first receiving end portion
610 may include a mounting flange (not shown) for receiving the
plurality of fasteners.
[0187] FIG. 9 illustrates a driveshaft assembly according to an
embodiment of the present invention. While the figures depict a
driveshaft assembly, it can be readily appreciated that the
invention can be applied to other assemblies where two or more
parts are rigidly joined together. The driveshaft assembly is
merely one exemplary embodiment.
[0188] The driveshaft assembly 700 is assembled along a
longitudinal axis 702. The driveshaft assembly 700 includes a shaft
704, an annular spacer 706, and a driveshaft end component 708. As
shown, the spacer 706 is disposed between a first receiving end
portion 710 of the shaft 704 and a first driveshaft end component
708, but it is understood the spacer 706 may be disposed between a
second receiving end portion (not shown) of the shaft 704 and a
second driveshaft end component (not shown).
[0189] The shaft 704 is a tubular, elongate body comprising the
first receiving end portion 710, the second receiving end portion
(not shown), and a center shaft portion 712 (shown in part),
wherein the center shaft portion 712 is bounded by the first 710
and second (not shown) receiving end portions. As shown in FIG. 9,
the shaft 704 may be hollow, with an inner surface 714 and a hollow
interior 716 extending along and through the shaft 704. The center
shaft portion 712 of shaft 704 may have a center shaft portion
inner diameter 718 that is substantially the same as a receiving
end portion inner diameter 720 of either or both of the first 710
or second (not shown) receiving end portions. Alternatively, the
center portion 712 of shaft 704 may have a center shaft portion
inner diameter 718 that differs from a receiving end portion inner
diameter 720 of either or both of the first 710 or second (not
shown) receiving end portions. As depicted in FIG. 9, the center
portion 712 of shaft 704 has a center shaft portion inner diameter
718 that is less than the receiving end portion inner diameter 720.
The first 710 or second (not shown) receiving end portions may be
formed by machining the shaft 704 in a secondary operation, but may
also be formed by any other method.
[0190] The first receiving end portion 710 comprises at least (i) a
first terminus 722 of wall 724, wherein the first terminus 722 has
a thickness 726 defined by the difference between the receiving end
portion inner diameter 720 and the receiving end portion outer
diameter 728, (ii) a second terminus 730, wherein the second
terminus 730 has a thickness 732 defined by the difference between
the receiving end portion inner diameter 720 and the center portion
inner diameter 718, and (ii) an opening 734 to hollow interior
716.
[0191] The shaft 704 may be formed by extrusion, but other
processes such as roll forming, tube milling, or machining may be
used. The shaft 704 may be formed from aluminum, a steel, or any
other metal. The shaft 704 may also be a composite shaft. A
composite shaft is comprised of, for example, a non-metallic center
portion, a metallic first distal end portion, and a metallic second
distal end portion. The non-metallic center portion may be formed
from carbon fiber.
[0192] The annular spacer 706 is a hollow, generally tubular shaped
body, with a first inner diameter 736, a second inner diameter 738,
and a first outer diameter 740. The spacer 706 also comprises an
outer surface 742, an inner surface 744, an interior 746, a wall
748 interposed between the outer 742 and inner 744 surfaces, and a
first terminal surface 750 and a second terminal surface 752. The
spacer 706 also comprises a main portion 754, with a first opening
756 to the interior 746 disposed therein, and an end portion 758,
with a second opening 760 to the interior 746 disposed therein.
[0193] The main portion 754 may further comprise a tapered portion
(not shown). The end portion 758 comprises a lip portion 762 and a
transition portion 764. The end portion 758 is formed with the wall
748 of the spacer 706 bent in an arcuate fashion toward the
interior 746 of the spacer 706. This arcuate bend in the wall 748
forms the transition portion 764 and has a radius of curvature
C.sub.i. The portion of the wall 748 that points to the interior
746 of the spacer 706 forms the lip portion 762. The lip portion
762 is unitary with the spacer 706 and may be substantially at a
right angle to the main portion 754 of the spacer 706. The wall 748
of the spacer 706 may increase in thickness along the longitudinal
axis 702 in the direction from the first opening 756 of the spacer
706 towards the end portion 758 of the spacer 706, thus forming a
tapered portion (not shown). The wall 748 of the spacer,
disregarding any taper, may have a minimum thickness of 0.0003
inches.
[0194] For the purposes of the instant description, the outer
surface 742 may be further categorized as 742A, 742B, or 742C,
depending on where along the spacer 706 the outer surface 742 is
geographically. To elaborate: 742A designates the outer surface 742
at the main portion 754; 742B designates the outer surface 742 at
the transition portion 764; and 742C designates the outer surface
742 at the lip portion 762. A reference to the outer surface 742
without the use of a letter is meant to indicate the outer surface
742 in total, or any portion thereof, without regard to geographic
location along the spacer 706.
[0195] Likewise, for the purposes of the instant description, the
inner surface 744 may be further categorized as 744A, 744B, or
744C, depending on where along the spacer 706 the inner surface 744
is geographically. To elaborate: 744A designates the inner surface
744 at main portion 754; 744B designates the inner surface 744 at
the transition portion 764; and 744C designates the inner surface
744 at the lip portion 762. A reference to the inner surface 744
without the use of a letter is meant to indicate the inner surface
744 in total, or any portion thereof, without regard to geographic
location along the spacer 706.
[0196] The spacer 706 may be formed from a polymeric material, or
from any other material, such as plastic, metal, paper, cardboard,
wood, paint, or fabric. The spacer 706 may be formed by injection
molding The spacer 706 may be formed from any other process, such
as heat shrinking, where, the spacer is loosely disposed on at
least a portion of the driveshaft end component 708 and heated,
causing the polymeric heat-shrink material to contract around at
least a portion of the driveshaft end component 708. Alternatively,
the spacer may comprise a pliable substrate wrapped around at least
a portion of the driveshaft end component 708. Further, the spacer
may comprise a coating applied to at least a portion of the
driveshaft end component 708, or as shown in FIG. 11A, the coating
may be applied to the inner surface 714A of the receiving end
portion 710. The spacer may comprise a UV-cured urethane coating on
at least a portion of the driveshaft end component 708 or the inner
surface 714A of the receiving end portion 710. Generally, the
UV-cured urethane coating would be sprayed onto the desired
component of the driveshaft assembly 700 and subsequently cured
with UV light.
[0197] The driveshaft end component 708 is a rigid body comprising
an insert end portion 766 in axial alignment with an attachment end
portion 768 (shown in part). The driveshaft end component 708 may
be formed by machining a blank, forging, or casting. The driveshaft
end component 708 may be formed from a metal such as aluminum or
steel. As shown, the driveshaft end component 708 is a unitary
body, but it may be formed from a plurality of coupled
components.
[0198] The insert end portion 766 comprises an end surface 770, an
edge 772, a spacer mounting seat 774, a spacer catch surface 776, a
shaft mounting seat 778, and a shaft catch surface 780, all in
axial alignment with one another.
[0199] The edge 772 is formed at the boundary between the end
surface 770 and the spacer mounting seat 774. The edge 772 has a
radius of curvature C.sub.2.
[0200] The spacer mounting seat 774 is an annular protrusion from
the shaft mounting seat 778. As shown, spacer mounting seat 774 is
substantially cylindrical and has a diameter 782 that is constant;
however, as suggested in FIGS. 11B and 12, the spacer mounting seat
774 may be tapered. Further, the spacer mounting seat 774 may
include features or be sized to facilitate welding the shaft 704 to
the driveshaft end component 708.
[0201] The spacer catch surface 776 is an annular, planar surface
that defines the boundary between the spacer mounting seat 774 and
the shaft mounting seat 778. The spacer catch surface 776
preferably lies in a plane substantially transverse to the
longitudinal axis 702 of the assembled driveshaft 700. However, the
spacer catch surface 776 may also extend between the spacer
mounting seat 774 and the shaft mounting seat 778 in ways other
than transverse, such as angled or curvilinear.
[0202] The shaft mounting seat 778 is an annular protrusion from
the attachment end portion 768 of the driveshaft end component 708.
As shown, the shaft mounting seat 778 has a constant diameter 784;
however, the shaft mounting seat 778 may be tapered. Further, the
shaft mounting seat 778 may include features or be sized to
facilitate welding the shaft 704 to the driveshaft end component
708.
[0203] The shaft catch surface 780 is an annular, planar surface
that defines the boundary between the insert end portion 766 and
the attachment end portion 768. The shaft catch surface 780
preferably lies in a plane substantially transverse to the
longitudinal axis 702 of the assembled driveshaft 700. However, the
shaft catch surface 780 may also extend between the shaft mounting
seat 778 and the attachment end portion 768 in ways other than
transverse, such as angled or curvilinear.
[0204] The attachment end portion 768 includes a coupling end (not
shown). The coupling end may comprise a yoke for coupling the
driveshaft end component 708 to a universal joint, a constant
velocity joint, or any other joint. Alternatively, the coupling end
may include a plurality of splines formed thereon, gear teeth
formed thereon, or the coupling end may include any other
fitting.
[0205] The outer diameter 740 of the spacer 706 is substantially
the same as the receiving end portion inner diameter 720 of the
shaft 704, thereby providing for an interference fit between the
spacer 706 and the shaft 704 upon assembly of the driveshaft 700.
Further, the receiving end portion inner diameter 720 of the shaft
704 is substantially the same as the diameter 784 of the shaft
mounting seat 778 of the driveshaft end component 708, thereby by
providing for an interference fit between the driveshaft end
component 708 and the shaft 704 upon assembly of the driveshaft
700.
[0206] The first inner diameter 736 of the spacer 706, equal to a
diameter of the second opening 760 encircled by the second terminal
surface 752, is less than the diameter 782 of the spacer mounting
seat 774.
[0207] The second inner diameter 738 of the spacer 706 is
substantially the same as the diameter 782 of at least a portion of
the spacer mounting seat 774, thereby providing for an interference
fit between the spacer 706 and at least a portion of the spacer
mounting seat 774.
[0208] The transition portion 764 has a radius of curvature,
C.sub.1, that is substantially the same as the radius of curvature,
C.sub.2, of the edge 772 formed between the end surface 770 and the
spacer mounting seat 774. That is, C.sub.1 C.sub.2, thus allowing
for substantially continuous contact between the inner surface 744
of the spacer 706 and at least a portion of the spacer mounting
seat 774 upon assembly of the driveshaft 700.
[0209] The thickness 786 of the spacer mounting seat 774, measured
as the distance along the longitudinal axis 702 between the end
surface 770 and the spacer catch surface 776, may be substantially
the same as a length 788 of the spacer 706, as measured along the
longitudinal axis 702 such that the first terminal surface 750
contacts the spacer catch surface 776. However, the length 788 of
the spacer 706 may be less than the thickness 786 of the spacer
mounting seat 774 such that the first terminal surface 750 does not
contact the spacer catch surface 776.
[0210] The spacer catch surface 776 may have a radial dimension 789
that is equal to the difference in the diameter 782 of the spacer
mounting seat and the diameter 784 of the shaft mounting seat 778.
The radial dimension 789 of the spacer catch surface 776 may or may
not be equal to a thickness 790 of the wall 748, wherein the
thickness 790 is equal to the difference between the second inner
diameter 738 and the outer diameter 740.
[0211] Upon assembly, the spacer 706 sits on at least a portion of
the spacer mounting seat 774 such that at least a first portion of
the end surface 770 is visible through the second opening 760 and
at least a second portion of the end surface 770 is in contact with
the inner surface 744C. The inner surface 744A contacts at least a
portion of the spacer mounting seat 774 and inner surface 744B
contacts edge 772.
[0212] The second terminal surface 752 is not in contact with the
spacer mounting seat 774. As noted above, the first terminal
surface 750 may or may not be in contact with the spacer catch
surface 776. If present, any tapered portion (not shown) would form
a smooth, stepless transition from the outer surface 742 of the
spacer 706 to the insert end portion 766.
[0213] The terminus 722 of the wall 724 of the shaft 704 contacts
the shaft catch surface 780. Further, the shaft 704 may sit on the
insert end portion 766 such that the shaft mounting seat 778 is
disposed within the hollow interior 716, forming an interference
fit between the shaft mounting seat 778 and the inner surface 714
of the shaft 704. Preferably, the shaft mounting seat 778 contacts
the inner surface 714 at the receiving end portion 710, designated
as 714A. Alternatively, the diameter 784 of the shaft mounting seat
778 may be less than the receiving end ,portion inner diameter 720
such that no interference fit is formed between the shaft mounting
seat 778 and the shaft 704.
[0214] At least a portion of the outer surface 742 of the spacer
706 contacts the inner surface 714 of the shaft 704, forming an
interference fit between the spacer 706 and the inner surface 714
of the shaft 704. Preferably, the portion of the outer surface 742
of the spacer 706 that contacts the inner surface 714 of the shaft
704 is the outer surface 742A at the main portion 754 of the spacer
706. Also preferably, spacer 706 contacts the inner surface 714 at
the receiving end portion 710, designated as 714A.
[0215] When the driveshaft assembly 700 is completed, the first
receiving end portion 710 is coupled to the driveshaft end
component 708 at the first receiving end portion 710 by a weld. The
first receiving end portion 710 may be coupled to the driveshaft
end component 708 by a magnetic pulse weld, a butt weld formed
therebetween, an arc seam weld formed through the shaft 704, or by
any other method of welding. Alternately, a plurality of fasteners
(not shown) may be used to couple the first receiving end portion
710 to the driveshaft end component 708. When the plurality of
fasteners is used to couple the first receiving end portion 710 to
the driveshaft end component 708, the first receiving end portion
710 may include a mounting flange (not shown) for receiving the
plurality of fasteners.
[0216] FIG. 10 illustrates a driveshaft assembly according to an
embodiment of the present invention. While the figures depict a
driveshaft assembly, it can be readily appreciated that the
invention can be applied to other assemblies where two or more
parts are rigidly joined together. The driveshaft assembly is
merely one exemplary embodiment.
[0217] The driveshaft assembly 800 is assembled along a
longitudinal axis 802. The driveshaft assembly 800 includes a shaft
804, an annular spacer 806, and a driveshaft end component 808. As
shown, the spacer 806 is disposed between a first receiving end
portion 810 of the shaft 804 and a first driveshaft end component
808, but it is understood the spacer 806 may be disposed between a
second receiving end portion (not shown) of the shaft 804 and a
second driveshaft end component (not shown).
[0218] The shaft 804 is a tubular, elongate body comprising the
first receiving end portion 810, the second receiving end portion
(not shown), and a center shaft portion 812 (shown in part),
wherein the center shaft portion 812 is bounded by the first 810
and second (not shown) receiving end portions. As shown in FIG. 10,
the shaft 804 may be hollow, with an inner surface 814 and a hollow
interior 816 extending along and through the shaft 804. The center
shaft portion 812 of shaft 804 may have a center shaft portion
inner diameter 818 that is substantially the same as a receiving
end portion inner diameter 820 of either or both of the first 810
or second (not shown) receiving end portions. Alternatively, the
center portion 812 of shaft 804 may have a center shaft portion
inner diameter 818 that differs from a receiving end portion inner
diameter 820 of either or both of the first 810 or second (not
shown) receiving end portions.
[0219] The first receiving end portion 810 comprises at least (i)
an opening 826 to hollow interior 816 and a shaft flange 828. The
shaft flange 828 comprises a shaft flange end surface 830 and a
plurality of shaft fastener apertures 832. The shaft flange 828 may
be formed integrally with the shaft 804.
[0220] The shaft 804 may be formed by extrusion, but other
processes such as roll forming, tube milling, or machining may be
used. The shaft 804 may be formed from aluminum, a steel, or any
other metal. The shaft 804 may also be a composite shaft. A
composite shaft is comprised of, for example, a non-metallic center
portion, a metallic first distal end portion, and a metallic second
distal end portion. The non-metallic center portion may be formed
from carbon fiber.
[0221] The annular spacer 806 is a hollow, generally tubular shaped
body, with a first inner diameter 836, a second inner diameter 838,
and a first outer diameter 840 and second outer diameter 842,
wherein the second outer diameter 842 may be substantially the same
as the second inner diameter 838. The spacer 806 also comprises an
outer surface 844, an inner surface 846, an interior 848, a wall
850 interposed between the outer 844 and inner 846 surfaces, and a
terminal surface 852. The spacer 806 also comprises a first end
portion 854, a second end portion 856, and a center portion 858,
wherein the center portion 858 is bounded by the first 854 and
second 856 end portions.
[0222] A first opening 860 is disposed within the first end portion
854. The first end portion 854 may further comprise a tapered
portion 862. The second end portion 856 comprises a lip portion 864
and a transition portion 866. The second end portion 856 is formed
with the wall 850 of the spacer 806 bent in an arcuate fashion
toward the interior 848 of the spacer 806. This arcuate bend in the
wall 850 forms the transition portion 866 and has a radius of
curvature, C.sub.1. The portion of the wall 850 that points to the
interior 848 of the spacer 806 forms the lip portion 864. The lip
portion 864 is unitary with the spacer 806 and may be substantially
at a right angle to the center portion 858 of the spacer 806. The
wall 850 of the spacer 806 may increase in thickness along the
longitudinal axis 802 in the direction from the first opening 860
of the spacer 806 towards the center portion 858 of the spacer 806,
thus forming the tapered portion 862. The wall 850 of the spacer,
disregarding the tapered portion 862, may have a minimum thickness
of 0.0003 inches.
[0223] For the purposes of the instant description, the outer
surface 844 may be further categorized as 844A, 844B, 844C, or
844D, depending on where along the spacer 806 the outer surface 844
is geographically. To elaborate: 844A designates the outer surface
844 at the tapered portion 862; 844B designates the outer surface
844 at the center portion 858; 844C designates the outer surface
844 at the transition portion 866; and 844D designates the outer
surface 844 at the lip portion 864. A reference to the outer
surface 844 without the use of a letter is meant to indicate the
outer surface 844 in total, or any portion thereof, without regard
to geographic location along the spacer 806.
[0224] Likewise, for the purposes of the instant description, the
inner surface 846 may be further categorized as 846A, 846B, or
846C, depending on where along the spacer 806 the inner surface 846
is geographically. To elaborate: 846A designates the inner surface
846 at the tapered 862 and center 858 portions; 846B designates the
inner surface 846 at the transition portion 866; and 846C
designates the inner surface 846 at the lip portion 864. A
reference to the inner surface 846 without the use of a letter is
meant to indicate the inner surface 846 in total, or any portion
thereof, without regard to geographic location along the spacer
806.
[0225] The spacer 806 may be formed from a polymeric material, or
from any other material, such as plastic, metal, paper, cardboard,
wood, paint, or fabric. The spacer 806 may be formed by injection
molding. The spacer 806 may be formed from any other process, such
as heat shrinking, where, the spacer is loosely disposed on at
least a portion of the driveshaft end component 808 and heated,
causing the polymeric heat-shrink material to contract around at
least a portion of the driveshaft end component 808. Alternatively,
the spacer may comprise a pliable substrate wrapped around at least
a portion of the driveshaft end component 808. Further, the spacer
may comprise a coating applied to at least a portion of the
driveshaft end component 808, or as shown in FIG. 11A, the coating
may be applied to the inner surface 814 of the receiving end
portion 810. The spacer may comprise a UV-cured urethane coating on
at least a portion of the driveshaft end component 808 or the inner
surface 814 of the receiving end portion 810. Generally, the
UV-cured urethane coating would be sprayed onto the desired
component of the driveshaft assembly 800 and subsequently cured
with UV light.
[0226] The driveshaft end component 808 is a rigid body comprising
an insert end portion 868 in axial alignment with an attachment end
portion 870 (shown in part). The driveshaft end component 808 may
be formed by machining a blank, forging, or casting. The driveshaft
end component 808 may be formed from a metal such as aluminum or
steel. As shown, the driveshaft end component 808 is a unitary
body, but it may be formed from a plurality of coupled
components.
[0227] The insert end portion 868 comprises an end surface 872, a
spacer mounting seat 874, a spacer catch surface 876, an edge 878,
a main insert portion 880, and a mounting flange 882, all in axial
alignment with one another.
[0228] The spacer mounting seat 874 is an annular protrusion from
the main insert portion 880.
[0229] The spacer catch surface 876 is an annular, generally planar
surface that defines the boundary between the spacer mounting seat
874 and the main insert portion 880. The spacer catch surface 876
preferably lies in a plane substantially transverse to the
longitudinal axis 802 of the assembled driveshaft 800. However, the
spacer catch surface 876 may also extend between the spacer
mounting seat 874 and the main insert portion 880 in ways other
than transverse, such as angled or curvilinear.
[0230] The main insert portion 880 is an annular protrusion from
the mounting flange 882. As shown, the main insert portion 880 is
substantially cylindrical and has a diameter 892 that is constant;
however, as suggested in FIGS. 11B and 12, the main insert portion
880 may be tapered. Further, the main insert portion 880 may
include features or be sized to facilitate welding the shaft 804 to
the driveshaft end component 808.
[0231] The edge 878 is formed at the boundary between the spacer
catch surface 876 and the main insert portion 880. The edge 878 has
a radius of curvature C.sub.2.
[0232] The mounting flange 882 comprises a mounting flange surface
884 and a plurality of mounting flange fastener apertures 886. The
mounting flange 882 is formed integrally with the driveshaft end
component.
[0233] The attachment end portion 870 includes a coupling end (not
shown). The coupling end may comprise a yoke for coupling the
driveshaft end component 808 to a universal joint, a constant
velocity joint, or any other joint. Alternatively, the coupling end
may include a plurality of splines formed thereon, gear teeth
formed thereon, or the coupling end may include any other
fitting.
[0234] The first outer diameter 840 of the spacer 806 is
substantially the same as the receiving end portion inner diameter
820 of the shaft 804, thereby providing for an interference fit
between the spacer 806 and the shaft 804 upon assembly of the
driveshaft 800.
[0235] The first inner diameter 836 of the spacer 806, equal to a
diameter of a second opening 888 to the interior 848 encircled by
the terminal surface 852, is substantially the same as the diameter
890 of the spacer mounting seat 874, thereby providing for an
interference fit between the spacer 806 and the spacer mounting
seat 874.
[0236] The second inner diameter 838 of the spacer 806 is
substantially the same as the diameter 892 of at least a portion of
the main insert portion 880, thereby providing for an interference
fit between the spacer 806 and at least a portion of the main
insert portion 880.
[0237] The thickness 894 of the spacer mounting seat 874, measured
as the distance along the longitudinal axis 802 between the end
surface 872 and the spacer catch surface 876, may be substantially
the same as a length 896 of the terminal surface 852, as measured
along the longitudinal axis 802. However, the thickness 894 of the
spacer mounting seat 874 may be such that the end surface 872 may
be recessed from, or protrude from, the second opening 888 of
spacer 806.
[0238] The spacer catch surface 876 may have a radial dimension
equal to the difference between the diameter 892 of the main insert
portion 880 and the diameter 890 of the spacer mounting seat
874.
[0239] The transition portion 866 has a radius of curvature,
C.sub.1, that is substantially the same as the radius of curvature,
C.sub.2, of the edge 878 formed between the spacer catch surface
876 and the main insert portion 880. That is, C.sub.1 C.sub.2, thus
allowing for substantially continuous contact between the inner
surface 846 of the spacer 806 and at least a portion of the insert
end portion 868 upon assembly of the driveshaft 800.
[0240] Upon assembly, the spacer 806 sits on at least a portion of
the insert end portion 868 such that the end surface 872 and spacer
mounting seat 874 are disposed within the second opening 888. The
inner surface 846C contacts the spacer catch surface 876 and the
inner surface 846A contacts at least a portion of the main insert
portion 880. Inner surface 846B contacts edge 878.
[0241] The terminal surface 852 contacts the spacer mounting seat
874, but end surface 872 would be visible through the second
opening 888 and is not in contact with the spacer 806. The end
surface 872 may be flush with the outer surface 844 of the spacer
806 or the end surface 872 may be recessed therefrom or protrude
therefrom. If present, the tapered portion 862 may form a smooth,
stepless transition from the outer surface 844 of the spacer 806 to
the main insert portion 880.
[0242] At least a portion of the outer surface 844 of the spacer
806 contacts the inner surface 814 of the shaft 804, forming an
interference fit between the spacer 806 and the inner surface 814
of the shaft 804. Preferably, the portion of the outer surface 844
of the spacer 806 that contacts the inner surface 814 of the shaft
804 is the outer surface 844B at the center portion 858 of the
spacer 806.
[0243] When the driveshaft assembly 800 is completed, a plurality
of fasteners (not shown) may be used to couple the first receiving
end portion 810 to the driveshaft end component 808. When the
plurality of fasteners is used to couple the first receiving end
portion 810 to the driveshaft end component 808, the shaft flange
end surface 830 and the mounting flange surface 884 will be in
contact and the plurality of shaft fastener apertures 832 and the
plurality of mounting flange fastener apertures 886 will be
aligned, thereby able to receive the plurality of fasteners (not
shown).
[0244] Alternatively, the first receiving end portion 810 may be
coupled to the driveshaft end component 808 at the first receiving
end portion 810 by a weld. The first receiving end portion 810 may
be coupled to the driveshaft end component 808 by a magnetic pulse
weld, a butt weld formed therebetween, an arc seam weld formed
through the shaft 804, or by any other method of welding.
[0245] FIG. 11A illustrates a shaft, with a annular spacer disposed
therein, according to an embodiment of the present invention. While
the figure depicts components of a driveshaft assembly, it can be
readily appreciated that the invention can be applied to other
assemblies where two or more parts are rigidly joined together. The
driveshaft assembly is merely one exemplary embodiment.
[0246] The driveshaft assembly (shown in part) is assembled along a
longitudinal axis 902. The driveshaft assembly (shown in part)
includes a shaft 904, an annular spacer 906, and a driveshaft end
component (not shown). As shown, the spacer 906 is disposed within
the shaft 904. The details of the individual features of the shaft,
or its construction or formation can be that of any of the
previously described embodiments. The distinguishing feature is
that, here, the spacer 906 is formed within the shaft 904.
Preferably, the spacer 906 is a coating applied to the inner
surface 914 of the shaft. Also preferably, the spacer 906 is
composed of a UV-cured urethane.
[0247] FIG. 11B illustrates a driveshaft end component, with an
annular spacer disposed thereon, according to an embodiment of the
present invention. While the figure depicts components of a
driveshaft assembly, it can be readily appreciated that the
invention can be applied to other assemblies where two or more
parts are rigidly joined together. The driveshaft assembly is
merely one exemplary embodiment.
[0248] The driveshaft assembly (shown in part) is assembled along a
longitudinal axis 902. The driveshaft assembly (shown in part)
includes a shaft (not shown), an annular spacer 906, and a
driveshaft end component 908. As shown, the spacer 906 is disposed
on the driveshaft end component 908. The details of the individual
features of the driveshaft end component 908, or its construction
or formation, can be that of any of the previously described
embodiments. Preferably the main insert portion 966 is tapered.
[0249] The details of the individual features of the spacer 906, or
its construction or formation, can be that of any of the previously
described embodiments. Preferably, the spacer 906 is a coating
applied to at least a portion of the driveshaft end component. Also
preferably the spacer 906 is composed of a UV-cured urethane.
[0250] FIG. 12 illustrates a driveshaft assembly according to an
embodiment of the present invention. While the figure depicts
components of a driveshaft assembly, it can be readily appreciated
that the invention can be applied to other assemblies where two or
more parts are rigidly joined together. The driveshaft assembly is
merely one exemplary embodiment.
[0251] The driveshaft assembly 900 is assembled along a
longitudinal axis 902. The driveshaft assembly 900 includes a shaft
904, an annular spacer 906, and a driveshaft end component 908. As
shown, the spacer 906 is disposed between a first receiving end
portion 910 of the shaft 904 and a first driveshaft end component
908, but it is understood the spacer 906 may be disposed between a
second receiving end portion (not shown) of the shaft 904 and a
second driveshaft end component (not shown).
[0252] The shaft 904 is a tubular, elongate body comprising the
first receiving end portion 910, the second receiving end portion
(not shown), and a center shaft portion 912 (shown in part),
wherein the center shaft portion 912 is bounded by the first 910
and second (not shown) receiving end portions. As shown in FIG. 12,
the shaft 904 may be hollow, with an inner surface 914 and a hollow
interior 916 extending along and through the shaft 904. The center
shaft portion 912 of shaft 904 may have a center shaft portion
inner diameter 918 that is substantially the same as a receiving
end portion inner diameter 920 of either or both of the first 910
or second (not shown) receiving end portions.
[0253] Alternatively, the center portion 912 of shaft 904 may have
a center shaft portion inner diameter 918 that differs from a
receiving end portion inner diameter 920 of either or both of the
first 910 or second (not shown) receiving end portions. The first
910 or second (not shown) receiving end portions may be formed by
machining the shaft 904 in a secondary operation, but may also be
formed by any other method.
[0254] The first receiving end portion 910 comprises at least (i) a
terminus 922 of wall 924, wherein the terminus 922 has a thickness
928 defined by the difference between the receiving end portion
inner diameter 920 and the receiving end portion outer diameter
930, (ii) an opening (not shown) to hollow interior 916.
[0255] The shaft 904 may be formed by extrusion, but other
processes such as roll forming, tube milling, or machining may be
used. The shaft 904 may be formed from aluminum, a steel, or any
other metal. The shaft 904 may also be a composite shaft. A
composite shaft is comprised of, for example, a non-metallic center
portion, a metallic first distal end portion, and a metallic second
distal end portion. The non-metallic center portion may be formed
from carbon fiber.
[0256] The annular spacer 906 is a hollow, generally tubular shaped
body, with an inner diameter 934, an outer diameter that is
substantially equal to diameter 920, an outer surface 942, an inner
surface 944, an interior (not shown), and a wall 948 interposed
between the outer 942 and inner 944 surfaces. The wall 948 of
spacer 906 may have a taper 950. The wall 948 of the spacer,
disregarding any tapered portion, may have a minimum thickness of
0.0003 inches.
[0257] The spacer 906 may be formed from a polymeric material, or
from any other material, such as plastic, metal, paper, cardboard,
wood, paint, or fabric. The spacer 606 may be formed by injection
molding. The spacer 906 may be formed from any other process, such
as heat shrinking, where, the spacer is loosely disposed on at
least a portion of the driveshaft end component 908 and heated,
causing the polymeric heat-shrink material to contract around at
least a portion of the driveshaft end component 908. Alternatively,
the spacer may comprise a pliable substrate wrapped around at least
a portion of the driveshaft end component 908. As shown in FIG.
11B, the spacer may comprise a coating applied to at least a
portion of the driveshaft end component 908, or as shown in FIG.
11A, the coating may be applied to the inner surface 914 of the
receiving end portion 910. The spacer may comprise a UV-cured
urethane coating on at least a portion of the driveshaft end
component 908 or the inner surface 914 of the receiving end portion
910. Generally, the UV-cured urethane coating would be sprayed onto
the desired component of the driveshaft assembly 900 and
subsequently cured with UV light.
[0258] The driveshaft end component 908 is a rigid body comprising
an insert end portion 958 in axial alignment with an attachment end
portion 960 (shown in part). The driveshaft end component 908 may
be formed by machining a blank, forging, or casting. The driveshaft
end component 908 may be formed from a metal such as aluminum or
steel. As shown, the driveshaft end component 908 is a unitary
body, but it may be formed from a plurality of coupled
components.
[0259] The insert end portion 958 comprises an end surface 962, a
spacer mounting seat 964, a main insert portion 966, a shaft
mounting seat 968, and a shaft catch surface 970, all in axial
alignment with one another.
[0260] The spacer mounting seat 964 is an annular protrusion from
the main insert portion 966. As shown, the spacer mounting seat 964
is substantially cylindrical and has a substantially constant
diameter substantially equal to the diameter 934. Further, the
spacer mounting seat 964 may include features or be sized to
facilitate welding the shaft 904 to the driveshaft end component
908.
[0261] The main insert portion 966 is an annular protrusion from
the shaft mounting seat 968. As shown, the main insert portion 966
is tapered. The main insert portion 966 may also include additional
features or be sized to facilitate welding the shaft 904 to the
driveshaft end component 908.
[0262] The shaft mounting seat 968 is an annular protrusion from
the attachment end portion 960 of the driveshaft end component 908.
Further, the shaft mounting seat 968 may be substantially
cylindrical, or may be tapered or include features or be sized to
facilitate welding the shaft 904 to the driveshaft end component
908.
[0263] The shaft catch surface 970 is an annular, planar surface
that defines the boundary between the insert end portion 958 and
the attachment end portion 960. The shaft catch surface 970
preferably lies in a plane substantially transverse to the
longitudinal axis 902 of the assembled driveshaft 900. However, the
shaft catch surface 970 may also extend between the shaft mounting
seat 968 and the attachment end portion 960 in ways other than
transverse, such as angled or curvilinear.
[0264] The attachment end portion 960 includes a coupling end (not
shown). The coupling end may comprise a yoke for coupling the
driveshaft end component 908 to a universal joint, a constant
velocity joint, or any other joint. Alternatively, the coupling end
may include a plurality of splines formed thereon, gear teeth
formed thereon, or the coupling end may include any other
fitting.
[0265] An outer diameter of the spacer 906 is substantially the
same as the receiving end portion inner diameter 920 of the shaft
904, thereby providing for an interference fit between the spacer
906 and the shaft 904 upon assembly of the driveshaft 900.
[0266] The inner diameter 938 of the spacer 906 is substantially
the same as the diameter of at least a portion of the spacer
mounting seat 964.
[0267] Upon assembly, the spacer 906 sits on at least a portion of
the insert end portion 958 such that at least a portion of the
spacer mounting seat 964 is disposed within the spacer 906 and the
inner surface 944 contacts at least a portion of the spacer
mounting seat 964.
[0268] At least a portion of the outer surface 942 of the spacer
906 contacts the inner surface 914 of the shaft 904, forming an
interference fit between the spacer 906 and the inner surface 914
of the shaft 904. Preferably, the outer surface 942 of the spacer
906 contacts the inner surface 914 at the receiving end portion
910, designated as 914A.
[0269] When the driveshaft assembly 900 is completed, the first
receiving end portion 910 is coupled to the driveshaft end
component 908 at the first receiving end portion 910 by a weld. The
first receiving end portion 910 may be coupled to the driveshaft
end component 908 by a magnetic pulse weld, a butt weld formed
therebetween, an arc seam weld formed through the shaft 904, or by
any other method of welding. Alternately, a plurality of fasteners
(not shown) may be used to couple the first receiving end portion
910 to the driveshaft end component 908. When the plurality of
fasteners is used to couple the first receiving end portion 910 to
the driveshaft end component 908, the first receiving end portion
910 may include a mounting flange (not shown) for receiving the
plurality of fasteners.
[0270] The advantages of the present invention will be obvious to
those skilled in the art. Such advantages include reduced fretting
between rigidly coupled driveshaft components. The spacer of the
present invention will also reduce or eliminate tinking. Further,
either or both of these results are achieved with a minimal
increase in expense or steps for assembly.
[0271] In accordance with the provisions of the patent statutes,
the present invention has been described in what is considered to
represent its preferred embodiments. However, it should be noted
that the invention can be practiced otherwise than as specifically
illustrated and described without departing from its spirit or
scope.
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