U.S. patent application number 14/343423 was filed with the patent office on 2014-08-07 for external rolling diaphragm overmoulded high speed constant velocity joint boot.
This patent application is currently assigned to GKN Driveline North America, Inc.. The applicant listed for this patent is Richard Alfred Compau, Michael James Miller. Invention is credited to Richard Alfred Compau, Michael James Miller.
Application Number | 20140221109 14/343423 |
Document ID | / |
Family ID | 47914706 |
Filed Date | 2014-08-07 |
United States Patent
Application |
20140221109 |
Kind Code |
A1 |
Miller; Michael James ; et
al. |
August 7, 2014 |
EXTERNAL ROLLING DIAPHRAGM OVERMOULDED HIGH SPEED CONSTANT VELOCITY
JOINT BOOT
Abstract
A constant velocity joint boot assembly includes a boot-can
having an axially extending main cylindrical body, a radially
extending transition portion, an axially extending and generally
cylindrical mounting portion. The radially extending transition
portion intersects the axially extending main cylindrical body and
the generally cylindrical mounting portion. A flexible boot member
may be attached to an inner surface of at least two of the
cylindrical body, the transition portion and the mounting portion
at a coupling region.
Inventors: |
Miller; Michael James;
(White Lake, MI) ; Compau; Richard Alfred; (Holly,
MI) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Miller; Michael James
Compau; Richard Alfred |
White Lake
Holly |
MI
MI |
US
US |
|
|
Assignee: |
GKN Driveline North America,
Inc.
Auburn Hills
MI
|
Family ID: |
47914706 |
Appl. No.: |
14/343423 |
Filed: |
September 21, 2011 |
PCT Filed: |
September 21, 2011 |
PCT NO: |
PCT/US2011/052568 |
371 Date: |
March 7, 2014 |
Current U.S.
Class: |
464/173 |
Current CPC
Class: |
F16D 3/845 20130101;
F16D 3/227 20130101; B29L 2031/748 20130101; F16D 2003/22316
20130101; B29K 2083/00 20130101; B29C 45/14 20130101; B29C 70/68
20130101 |
Class at
Publication: |
464/173 |
International
Class: |
F16D 3/84 20060101
F16D003/84 |
Claims
1. A constant velocity joint boot comprising: a boot-can having an
axially extending main cylindrical body; a radially extending
transition portion; an axially extending and generally cylindrical
mounting portion, wherein the radially extending transition portion
intersects the axially extending main cylindrical body and the
generally cylindrical mounting portion; and a flexible boot member
attached to an inner surface of at least two of the cylindrical
body, the transition portion and the mounting portion at a coupling
region.
2. The constant velocity joint boot of claim 1, wherein the
flexible boot is configured as a unitary body with out
apertures.
3. The constant velocity joint boot of claim 1, wherein the
boot-can is configured as a unitary body.
4. The constant velocity joint system of claim 1, wherein the
flexible boot and the boot-can are coupled at an approximate length
of at least 8.5 mm to 14.5 mm across at least two of the main
cylindrical body, the radially extending transition portion and the
cylindrical mounting portion.
5. The constant velocity joint system of claim 1, wherein the
flexible boot has a cross section that is approximately 1.5 mm to 3
mm thick at the coupling region.
6. The constant velocity joint system of claim 1, wherein the
flexible boot includes an angled projection positioned adjacent an
intersection between the radially extending portion and a generally
cylindrical axially extending mounting portion.
7. The constant velocity joint system of claim 1, wherein the boot
is overmoulded to the boot-can.
8. The constant velocity joint system of claim 1, wherein the angle
is at least one of an angle greater than 90.degree. and an angle
less than 90.degree..
9. The constant velocity joint system of claim 1, wherein at least
one of the main cylindrical body, the radially extending transition
portion and the cylindrical mounting portion is generally
rigid.
10. A constant velocity joint sealing system, comprising: a
constant velocity joint, the joint having an inner joint member,
and an outer joint member connected to said inner joint member; and
a constant velocity joint boot assembly, the boot assembly having a
flexible boot adhered to a boot-can at a coupling region, the
coupling region having at least one axially extending surface and
at least one radially extending surface intersecting the axially
extending surface at an angle, wherein the flexible boot is
selectively compressible to form a seal when the boot-can is
fixedly secured with the outer joint member.
11. The constant velocity joint system of claim 9, wherein the two
regions include a predetermined dimensional coupling region.
12. The constant velocity joint system of claim 9, wherein the
flexible boot and the boot-can are adhered at an approximate length
of at least 8.5 mm to 14.5 mm across at least two of the main
cylindrical body, the radially extending transition portion and the
cylindrical mounting portion.
13. The constant velocity joint system of claim 9, wherein the
flexible boot has a cross section that is approximately 1.5 mm to 3
mm thick at the coupling region.
14. The constant velocity joint system of claim 9, wherein the
flexible boot includes an angled projection positioned adjacent an
intersection between the radially extending portion and a generally
cylindrical axially extending mounting portion.
15. The constant velocity joint system of claim 9, wherein the
flexible boot is configured as an external rolling diaphragm.
16. The constant velocity joint system of claim 9, wherein the
angle is approximately 90.degree..
17. The constant velocity joint system of claim 9, wherein the
angle ranges from 70.degree.-110.degree..
18. The constant velocity joint system of claim 9, wherein the
flexible boot is a unitary body without apertures, and the boot-can
is a unitary body.
19. The constant velocity joint system of claim 9, wherein the
constant velocity joint and the joint boot assembly are sealed and
resilient to pressure differentiations when fixedly secured
together, such that no atmospheric vent is included.
20. The constant velocity joint system of claim 9, wherein the
angle is at least one of an angle greater than 90.degree. and an
angle less than 90.degree..
Description
TECHNICAL FIELD
[0001] The present disclosure generally relates to constant
velocity joints and, more particularly, to high-speed constant
velocity joint and external rolling diaphragm boot cover
assemblies.
BACKGROUND
[0002] Constant velocity joints and similar rotating couplings
operate to transmit torque between two rotational members. The
constant velocity joint typically includes an inner joint member
for engagement with one rotational member, an outer joint member
for engagement with the other rotational member, and a boot cover
assembly or a grease cover to enclose and protect the rotating
assembly positioned within the outer member during operation. Since
the boot cover assembly is partially flexible, the boot cover
assembly is able to seal around one of the rotating members while
permitting articulation and relative axial movement between the two
rotating members. The boot cover assembly provides a barrier to
retain the grease in the internal cavity of the joint so as to
reduce friction and extend the life of the joint. The boot cover
assembly helps to seal out dirt, water and other contaminants to
protect the functionality of the joint.
[0003] Constant velocity joints require constant lubrication
(grease) to remain in operation in the environment in which they
are utilized. Typically, such joints use a sealed system to contain
the grease, the main component of which is the boot cover assembly
that includes a boot and associated mounting can. Boots come in a
variety of types. Some examples include convoluted, internal
rolling diaphragm (IRD) and external rolling diaphragm (ERD).
Particularly relating to IRD and ERD boots, the current industry
standard is to have the diaphragm boot crimped onto the mounting
can, and then to have the mounting can fit onto the joint. The
mounting can and boot may be vulcanized together or crimped
together at the top only, which allows grease that is under
pressure from centrifugal forces during the joint rotation to be
pushed between the sides of the boot and the mounting can
(blow-out).
[0004] However, an important characteristic of the constant
velocity joint is the ability of the joint to allow relative axial
movement between two shafts while maintaining a seal to the outside
environment. Typically, constant velocity joints include a seal
groove that extends circumferentially about the outer surface of
the outer member. This groove is generally machined or cut into the
outer joint member, causing additional labor, cost and time. The
groove provides a channel for receiving and positioning an o-ring
type seal at a connection point between the boot assembly, boot-can
and the outer member of the constant velocity joint. The seal is
used to help prevent the blow-out phenomenon associated with the
build-up of pressure.
[0005] Additionally, the centrifugal forces and friction associated
with the internal components of the constant velocity joint
assembly result in expansion or ballooning of the flexible boot
cover as a result of the pressure created from heat and high speed
operation. The deformation of the flexible boot cover may be
affected by lubricant load, a pumping action of the lubricant due
to constant velocity joint articulation, temperature, speed,
release of gas volatiles from the grease, and the shape of the
flexible boot. The constant expansion and contraction of the
flexible member results in fatigue, wear and eventual failure of
the flexible boot and ultimately the constant velocity joint.
Typically, a vent is provided to relieve any pressure and minimize
or eliminate the expansion of the flexible boot. However, this vent
also allows dirt, water and other debris to enter the constant
velocity joint. Specifically, venting the constant velocity joint
can lead to lubricant leakage or loss, as well as the infiltration
of contaminants into the joint, reducing its overall life.
[0006] What is needed, therefore, is a constant velocity joint and
boot cover assembly that eliminates the need for a separate seal
disposed about the outer surface of the outer member. Additionally,
there is a need for a constant velocity joint and boot cover
assembly that is configured to eliminate the need for a flexible
boot vent.
SUMMARY
[0007] The present application discloses a constant velocity joint
boot assembly. The constant velocity joint boot assembly may
include a boot-can having an axially extending main cylindrical
body, a radially extending transition portion, an axially extending
and generally cylindrical mounting portion. The radially extending
transition portion may intersect the axially extending main
cylindrical body and the generally cylindrical mounting portion. A
flexible boot member may be attached to an inner surface of at
least two of the cylindrical body, the transition portion and the
mounting portion at a coupling region for use with an associated
constant velocity joint (CVJ). The present application may be
applicable to a wide variety of CVJ's, including, but not limited
to, plunging, tripod, fixed and high speed. The boot may be affixed
to at least two internal surfaces of the boot-can by any known
process such as, but not limited to, overmoulding, adhering and
bonding. Specifically, the flexible boot may be affixed to a first
joint connection end, such that the boot creates a seal between an
end surface of the CVJ and the first end of the boot-can. By
positioning the flexible boot between the boot-can and the CVJ, the
need for an exteriorly positioned seal is eliminated.
BRIEF DESCRIPTION OF DRAWINGS
[0008] Referring now to the drawings, preferred illustrative
embodiments are shown in detail. Although the drawings represent
some embodiments, the drawings are not necessarily to scale and
certain features may be exaggerated, removed, or partially
sectioned to better illustrate and explain the present disclosure.
Further, the embodiments set forth herein are not intended to be
exhaustive or otherwise limit or restrict the claims to the precise
forms and configurations shown in the drawings and disclosed in the
following detailed description:
[0009] FIG. 1 illustrates a side cross-sectional view of an
exemplary constant velocity joint assembly and attached flexible
boot assembly;
[0010] FIG. 2A illustrates a side cross-sectional view of an
exemplary flexible boot assembly;
[0011] FIG. 2B illustrates an enlarged view of encircled area 2B of
the exemplary flexible boot and boot-can coupling region;
[0012] FIG. 3 illustrates an isometric view of an exemplary
flexible boot assembly with the flexible boot in an "as molded"
position;
[0013] FIG. 4 illustrates an isometric view of an exemplary
flexible boot assembly with the flexible boot and further including
the diaphragm in position;
[0014] FIG. 5 illustrates an isometric cross-sectional view of an
exemplary flexible boot assembly with the flexible boot diaphragm
in position; and
[0015] FIG. 6 illustrates an isometric partial cross-sectional view
of an exemplary constant velocity joint assembly and attached
flexible boot assembly.
DETAILED DESCRIPTION
[0016] FIG. 1 illustrates an exemplary CVJ assembly 110
incorporating an exemplary arrangement of a boot assembly 112. More
specifically, CVJ assembly 110 may include flexible boot assembly
112 and CVJ 114. The CVJ 114 may include an outer joint member 116,
an inner joint member 118, a joint cage 120 and a plurality of
torque transmitting balls 122. The outer joint member 116 may
include a first end 124 and a second end 126. The first end 124
maybe configured to mate with the flexible boot assembly 112, and
the second end 126 maybe engaged with a second rotational member
(not shown). A first rotational member or drive shaft 128 may
extend through the flexible boot assembly 112 and may be engaged
with or affixed to the inner joint member 118.
[0017] With continued reference to FIG. 1, an exemplary arrangement
of the flexible boot assembly 112 includes a generally cylindrical
boot-can 130 configured to receive a flexible boot 132. As
discussed above, flexible boots may come in a variety of types.
Merely by way of example, internal rolling diaphragm (IRD) and
external rolling diaphragm (ERD) boots are discussed in greater
detail below. The flexible boot 132 includes a first end 144 and a
second end 146. The first end 144 may be configured to bond to the
generally cylindrical boot-can 130. The exemplary flexible boot 132
may be constructed of a flexible material, such as, but not limited
to, rubber based products, plastics, silicones, elastomers,
silicone, thermoplastic elastomer (TPE), and any other flexible
composite materials. It is understood, however, that other suitable
materials may be used depending on the application, such as, but
not limited to, materials having a hardness value in the range of
about 55-75 Shore A or about 35-55 Shore D. In another embodiment,
the material may have a hardness of about 40-44 Shore D. Materials
that are specifically compatible with a typical flexible boot cover
assembly 112 environment are relatively rigid thermoplastic
polyesters due to the desirable bonding formed in coupling region
140 during a molding process, which may be used to secure the boot
132 to the boot-can 130, as will be explained below.
[0018] The generally cylindrical boot-can 130 may include an
axially extending main cylindrical body 134, a radially extending
transition portion 136, and an axially extending and generally
cylindrical mounting portion 138. The boot-can 130 is formed of a
first substantially rigid material, such as, but not limited to,
aluminum, steel, carbon fiber and composite.
[0019] In one exemplary arrangement, the flexible boot 132 may be
molded directly to the boot-can 130 to create a physical and/or a
chemical bond at a coupling region 140. The coupling region 140 may
extend from a portion of the axially extending main cylindrical
body 134, across the radially extending transition portion 136 and
terminating at a portion of the axially extending and generally
cylindrical mounting portion 138. The coupling region 140 allows
the bond between the flexible boot 132 and the boot-can 130 to
occur on at least two surfaces. However, the exemplary arrangement,
as shown in the drawings, details that the two surfaces are
perpendicular.
[0020] As illustrated, the generally cylindrical mounting portion
138 may be configured to engage with and mate to an outer surface
of the second end 126 of the outer joint member 116. Additionally,
the second end 126 may also include an engagement groove 150 that
extends circumferentially about the outer surface of the outer
joint member 116. The engagement groove 150 may provide a tactile
indicator or positive stop for engaging a lip 142 on the generally
cylindrical mounting portion 138.
[0021] Turning to FIGS. 2A and 2B, a view showing an exemplary
flexible boot assembly 112 with an optional angle is depicted. In
these figures, the flexible boot 132 is illustrated in a post
assembled "as-molded" state, where the boot-can 130 is placed in a
mold (not shown), and the boot is molded in a cone shape, which
generally mimics the characteristics of an IRD shape. During
assembly the boot may be inverted to create the ERD shape, which
creates a diaphragm 154 (shown in FIG. 1), as discussed above. The
axially extending main cylindrical body 134 intersects the radially
extending transition portion 136 and in one exemplary arrangement,
forms a first generally 90.degree. angle at the coupling region
140. Additionally, the transition portion 136 intersects the
generally cylindrical mounting portion 138 to create a second
generally 90.degree. angle, which as illustrated, the first and
second generally 90.degree. angle intersections may resemble a
stepped feature. It should be known that additional intersecting
angles may be sufficient provided the surfaces 134, 138 intersect
the transition portion 136. Additionally, other boot-can 132
configurations may also be used including boot-cans that have
non-linear walls with bends or other shaped features configured
in/on the boot-can 130 based on the clearance needs and application
needs, as related to the various constant velocity joints employed.
These features may include projections 160 at an outer edge or
curves formed on the boot-can 130 for clearance related to the
internal constant velocity joint 114 components 118, 120 and
122.
[0022] With continued reference to FIG. 2A, the flexible boot 132,
as discussed above, in one exemplary arrangement is illustrated as
being overmoulded to the boot-can 130 at the coupling region 140,
such that a portion of the flexible boot 132 and a portion of the
boot-can 130 are bonded together at a predetermined dimensional
area using known methods. Specifically, the predetermined
dimensional area includes the flexible boot 132, which may be, in
on exemplary arrangement, approximately 1.5 mm to 3 mm thick in the
area directly adjacent the axially extending portion of the
coupling region 140, and the flexible boot 132 may be approximately
0.25 mm to 1 mm thick at the coupling region adjacent the
transition portion 136. The area bonded to the axially extending
main cylindrical body 134 may extend approximately 7.5 mm to 10.5
mm from an internal face 148 of the transition portion 136 along
the interior surface of the coupling region 140. Thus, it should be
known that the coupling region 140 bonds a total length of
approximately 8.5 mm to 14.5 mm, covering at least two external
surfaces of the flexible boot 132 and the internal surfaces of the
boot-can 130, as discussed above.
[0023] Turning specifically to FIG. 2B, a continued area of
adhesion is illustrated in detail. The area depicts an angled
projection 156 positioned adjacent an intersection of the
transition portion 136 and the generally cylindrical mounting
portion 138. Specifically, in one exemplary arrangement, the area
has an approximate 45.degree. angle, which may provide an
additional thickness of flexible boot 132 materials at the interior
corner of the 90.degree. angle. This additional thickness of
material may be flexible enough to provide additional sealing
capabilities. Specifically, the flexible boot 132 may compress and
assume a connection area (not illustrated) between the CVJ face 162
and the boot-can coupling region 140 when the flexible boot
assembly 112 is mated with the CVJ assembly 114 to create the CVJ
assembly 110. The created seal between the two assemblies 112, 114
eliminates the need for an auxiliary seal (not shown) positioned on
the outer surface of the outer joint member 116 as is commonly
found in previous CVJ assemblies (not shown).
[0024] Referring to FIGS. 3 and 4, the flexible boot assembly 112
may be inverted to convert the "as-molded" outwardly extending IRD
conical shaped boot (See FIG. 3) to an ERD shape where the flexible
boot 132 arcs inwardly upon itself (See FIG. 4) to create the
diaphragm 154. Specifically, turning to FIG. 5 an exemplary section
view of the flexible boot assembly 112 is illustrated with the
first end 144 molded to the boot-can 130 at the coupling region 140
and the second end 146 is now adjacent the coupling region 140. The
ERD shape creates the external diaphragm 154, which appears as a
balloon effect that may expand and contract without permanent
deformation that may damage the flexible boot 132.
[0025] Turning to FIG. 6, an isometric partial cross-sectional view
of the exemplary CVJ assembly 110 is illustrated. Specifically,
when the boot-can 130 is engaged with the CVJ 114, a portion of the
flexible boot 132 that is bonded to the coupling region 140 may be
in a compressed between the boot-can 130 and the CVJ face 162 of
the outer joint part 116. Compression of the portion of the
flexible boot 132 provides a seal between the CVJ 114 and the
boot-can 130. The angled area 156, if incorporated, may provide
additional material to compress to seal the compression area (not
shown) that may be present due to a chamfer or other machined
feature on the end of the CVJ 114. Additionally, as illustrated in
FIG. 4, the second end 146 of the flexible boot 132 extends
circumferentially around the rotating member 128. A band 158 or
other type of tightening element may be used to secure the flexible
boot 132 to the shaft/rotating member 128 that is engaged with the
inner joint member 118 of the CVJ 114.
[0026] The exemplary embodiments of FIGS. 1-6 depict an exemplary
CVJ assembly 110 that provides an operator with the ability to
reduce manufacturing time and provides a more resilient CVJ with an
increased life. As illustrated in the exemplary embodiments, an
operator (not shown) may assemble the flexible boot assembly 112
and the CVJ assembly 114 without the use of an auxiliary seal
extending about the outside edge of the outer joint 116.
Additionally, by providing a flexible boot assembly 112 that is
adhered to the boot-can 130, as described above, the assembly is
able to use a flexible boot that has a unitary body without the
need for any auxiliary vent apertures. Thus, as discussed above,
exemplary embodiments have been illustrated that depict a CVJ
assembly 110 that includes a flexible boot that compresses between
the coupling region 140 and the CVJ face 162. This compressed area
creates a sealed feature between the two 140, 162 and eliminates
the exterior seal while providing a solid attachment surface.
Specifically, when the second end 146 of the flexible boot 132 is
secured to the shaft 128 by the band 158 the flexible boot 132 is
able to expand and contract without the use of a vent. Therefore,
the elimination of the vent apertures provides a more resilient CVJ
assembly by eliminating any debris or contaminates that may flow
into the previously provided vent on previous designed boot
assemblies (not shown).
[0027] The present invention has been particularly shown and
described with reference to the foregoing embodiment, which are
merely illustrative of the best modes for carrying out the
invention. It should be understood by those skilled in the art that
various alternatives to the embodiments of the invention described
herein may be employed in practicing the invention without
departing from the spirit and scope of the invention as defined in
the following claims. It is intended that the following claims
define the scope of the invention and that the method and apparatus
within the scope of these claims and their equivalents be covered
thereby. This description of the invention should be understood to
include all novel and nonobvious combinations of elements described
herein, and claims may be presented in this or a later application
to any novel and non-obvious combination of these elements.
Moreover, the foregoing embodiments are illustrative, and no single
feature or element is essential to all possible combinations that
may be claimed in this or a later application.
* * * * *