U.S. patent application number 11/778512 was filed with the patent office on 2008-01-17 for flexible couplings.
Invention is credited to Anthony L. Hauck.
Application Number | 20080015035 11/778512 |
Document ID | / |
Family ID | 35908196 |
Filed Date | 2008-01-17 |
United States Patent
Application |
20080015035 |
Kind Code |
A1 |
Hauck; Anthony L. |
January 17, 2008 |
FLEXIBLE COUPLINGS
Abstract
A flexible coupling including a first hub having an inner face,
a flexible insert having a plurality of exterior lobes and a
plurality of interior lobes, a retainer ring having an interior
which engages the exterior lobes of the flexible insert, and a
second hub having an exterior surface contoured to engage the
interior lobes of the flexible insert.
Inventors: |
Hauck; Anthony L.;
(Huntington Beach, CA) |
Correspondence
Address: |
GREENBERG TRAURIG LLP (LA)
2450 COLORADO AVENUE, SUITE 400E
INTELLECTUAL PROPERTY DEPARTMENT
SANTA MONICA
CA
90404
US
|
Family ID: |
35908196 |
Appl. No.: |
11/778512 |
Filed: |
July 16, 2007 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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10917940 |
Aug 13, 2004 |
7244186 |
|
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11778512 |
Jul 16, 2007 |
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Current U.S.
Class: |
464/75 |
Current CPC
Class: |
F16D 3/68 20130101; F16D
3/76 20130101 |
Class at
Publication: |
464/075 |
International
Class: |
F16D 3/18 20060101
F16D003/18 |
Claims
1. A flexible torque transmitting belt comprising: a flexible
plastic body having an inner and outer surface; said outer surface
including a plurality of exterior lobes, each of a selected first
width, each having a perimeter including a circular portion
disposed between first and second flat sides, the distance between
respective ends of said flat sides defining said first width; each
exterior lobe comprising a solid body of plastic material in the
space encompassed by said perimeter and a line joining said
respective ends; said inner surface including a plurality of
interior lobes, each of a selected second width, each including a
circular portion disposed between first and second flat sides, the
distance between the respective ends of said flat sides defining
said second width; and each interior lobe comprising a solid body
of plastic material in the space encompassed by said perimeter and
a line joining said respective ends.
2. The flexible belt of claim 1 wherein said interior lobes
alternate with said exterior lobes such that, as one proceeds about
a circumference of said body one encounters a first exterior lobe,
then an interior lobe, then an exterior lobe, then an interior lobe
in repeating fashion.
3. The flexible belt of claim 1 wherein said first and second
widths are equal.
4. The flexible belt of claim 2 wherein said exterior lobes and
interior lobes are disposed on a circular central annular portion
of said body providing a constant shear section.
5. The flexible belt of claim 2 wherein said first and second
widths are equal.
6. The flexible belt of claim 4 wherein said first and second
widths are equal.
7. A flexible torque transmitting belt comprising: a flexible
plastic body having an inner and outer surface; said outer surface
including a plurality of exterior lobes, each of a selected first
width, each including first and second flat sides, the distance
between respective ends of said flat sides defining said first
width, each exterior lobe having a perimeter comprising the first
flat side leading into a first radiused corner, the second flat
side leading into a second radiused corner, the radiused corners
being connected by a central circumferentially disposed segment;
each exterior lobe comprising a solid body of plastic material in
the space defined by said perimeter and a line between said
respective ends of said first and second flat sides; said inner
surface including a plurality of interior lobes, each of a selected
second width, each including third and fourth flat sides, the
distance between the respective ends of said flat sides defining
said second width, the third flat side leading into a third
radiused corner, the fourth flat side leading into a fourth
radiused corner, the third and fourth radiused corners being
interconnected by a central circumferentially disposed segment;
each interior lobe comprising a solid body of plastic material in
the space encompassed by said perimeter and a line between said
respective ends of said third and fourth flat sides; the first,
second, third and fourth flat sides comprising driving surfaces,
the first, second third and fourth radiused corners being shaped
and dimensioned to provide a locking function in relation to a
cooperating well of a cooperating coupling component.
8. The flexible belt of claim 1 wherein said interior lobes
alternate with said exterior lobes such that, as one proceeds about
a circumference of said body one encounters a first exterior lobe,
then an interior lobe, then an exterior lobe, then an interior lobe
in repeating fashion.
Description
RELATED APPLICATIONS
[0001] This application is a continuation of U.S. patent
application Ser. No. 10/917,940, entitled "Flexible Couplings,"
filed on Aug. 13, 2004, to be issued on Jul. 17, 2007 as U.S. Pat.
No. 7,244,186, the contents of which are hereby incorporated by
reference in its entirety.
BACKGROUND OF THE INVENTION
[0002] 1. Filed of Invention
[0003] The invention set forth in this specification pertains to
new and improved flexible couplings and, more particularly, to such
couplings having advantageous features of both shear and
compression style couplings.
[0004] 2. Description of Related Art
[0005] Flexible couplings have long been used for the purpose of
transmitting rotation from one shaft to another. Such couplings are
normally used in order to accommodate comparatively minor shaft
alignment problems such as are occasionally encountered because of
manufacturing or assembly errors. Because of the fact that these
devices are widely used and have been known and used for many
years, many different types of flexible couplings have been
proposed, built, and used.
[0006] Certain particular flexible couplings have been manufactured
in the past so as to include two hubs or hub elements which are
adapted to be connected to the shafts joined by the coupling. These
hubs are each provided with extending lugs, teeth, or ribs serving
as holding means so as to be engaged by corresponding projections
on a band-like or belt-like motion transmitting means in order to
cause the hubs to rotate in synchronism as one of the shafts is
rotated. The bands or belts used in these prior couplings have been
flexible, somewhat resilient belts capable of being wrapped around
the hubs so that the projections on them engage the holding means
on the hubs.
[0007] A metal band or ring is typically used to retain the belt in
position wrapped around the hubs. The interior of the band is
shaped and dimensioned so that the band may be slid axially
relative to the hubs during the assembly and disassembly of the
coupling so that the band fits over the belt when the coupling is
assembled so as to conform closely to the exterior of the belt.
[0008] Some coupling designs have provided a pair of
oppositely-disposed axial grooves in the outer surface of the belt
and a pair of oppositely-disposed pins in the inner surface of the
metal band. The pins are located so as to slide into the grooves as
the metal band is installed along a line parallel to the axis of
rotation of the hubs. The pins thus position the band and provide a
degree of retention. However, if the shafts are grossly misaligned,
the metal band will "walk-off" the belt, causing the coupling to
come apart. The axial grooves have also been provided with an
enlarged central portion such that the pins must be forced through
the entrance of the axial groove and then "pop" into place in the
central portion to give a tactile indication that the metal band is
properly positioned with respect to the flexible belt.
[0009] In our U.S. Pat. Nos. 6,024,644 and 5,738,585, we have
disclosed improved "lock-on" apparatus for improving the retention
of the aforementioned metal retainer bands. This improved apparatus
employs an axial groove for initially receiving a pin located on
the underside of the metal retainer band and a circumferential
groove opening into the axial groove and into which the retainer
band pin may be rotated. In the embodiments illustrated in the
referenced applications, the axial groove is bisected by a radial
line which also bisects one of the lobes or projections of the
flexible belt. The circumferential groove is relatively short,
typically having been selected to be two times the width of the
retainer ring pin. In practice, such apparatus must contend with
vibrations, harmonics, rotation, misalignment and various stresses
and forces on the component parts.
SUMMARY
[0010] The following is a summary of various aspects and advantages
realizable according to various embodiments of the invention. It is
provided as an introduction to assist those skilled in the art to
more rapidly assimilate the detailed design discussion which ensues
and does not and is not intended in any way to limit the scope of
the claims which are appended hereto in order to particularly point
out the invention.
[0011] Accordingly, disclosed hereafter is a flexible coupling
including a first hub having an inner face and a flexible insert
having a plurality of exterior lobes and a plurality of interior
lobes. A retainer ring is provided having an interior which engages
the exterior lobes of the first hub, while a second hub has an
exterior surface contoured to engage the interior lobes. The
exterior and interior lobes may each have a rounded contour formed
between two flat faces, which facilitates torque transmission.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] An illustrative and presently preferred embodiment of the
invention will now be described in detail in conjunction with the
drawings of which:
[0013] FIG. 1 is an exploded perspective of a coupling according to
a preferred embodiment;
[0014] FIG. 2 is a side view of the coupling of FIG. 1;
[0015] FIG. 3 is a perspective end view illustrating a hub, insert
and retainer components in assembled relation:
[0016] FIG. 4 is a perspective view of the coupling in the
assembled state;
[0017] FIG. 5 is a side cross view of the coupling in the assembled
state;
[0018] FIG. 6 is a side cross sectional view of an embodiment
according to the invention;
[0019] FIG. 7 is a side cross section view of an embodiment
according to the invention;
[0020] FIG. 8 is a cross section view of an alternate
embodiment;
[0021] FIG. 9 is an enlarged view of a portion of the embodiment of
FIG. 8;
[0022] FIG. 10 is a side view of an alternate embodiment;
[0023] FIG. 11 is a perspective view of the embodiment of FIG. 10;
and
[0024] FIG. 12 is a perspective view of an alternate
embodiment.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0025] The coupling of the illustrative embodiment includes a first
hub 13, a flexible insert 15, a second hub 17 and a retainer member
19. The first hub 13 includes an interior bore 22, a first
cylindrical segment 21 and a mounting flange 23 having a circular
outer edge 25. The face 27 of the flange 23 has a number of
mounting holes 29 therein, each of which lies equally spaced on a
circle of lesser diameter than that of the outer edge 25.
Conventional fastening devices such as screw 28 may be used to
secure the hubs to respective shafts.
[0026] The insert 15 is preferably fabricated from a flexible
material such as, for example, a suitable urethane, and is
preferably split so as to facilitate "wraparound" installation. The
outer surface 31 of the insert 15 features a number of equally
spaced exterior lobes 33, 34, 35, 36, 37, 38 projecting therefrom.
The lobes, e.g., 33, are formed about equally spaced radii
extending from the center of the insert 15. The interior surface of
the insert 15 features a number of interiorly projecting lobes 52,
53, 54, 55, 56, 57, which, in the embodiment of FIG. 1, alternate
with the exterior lobes 33, 34, etc. In other words, as one
proceeds about the circumference of the insert 15 one encounters a
first exterior lobe 33, then an interior lobe 52, then a second
exterior lobe 34, then a second interior lobe 53, etc.
[0027] The second hub 17 includes a cylindrical segment 43 and an
inseit-mounting segment or portion 45. The insert-mounting portion
45 includes a number of wells or receptacles 47 which are shaped
and dimensioned to mate snugly with the interior lobes, e.g., 52,
53, of the insert 15. The hub 17 is preferably machined as a
unitary part from a single piece of metal stock, but of course
could be constructed in various other fashions. The second hub 17
further includes an interior bore 44, typically of circular cross
section dimensioned to receive a shaft of cooperating
apparatus.
[0028] The interior 49 of the retainer 19 is specially contoured,
shaped and dimensioned to receive and snugly mate with the exterior
lobes, e.g., 33, 34, of the insert 15 when the coupling is in the
assembled state. The retainer 19 has a first face 61 (FIG. 3),
which receives and passes the insert 15 into mating position with
the exterior lobes 33, 34, etc., and a second face 63 (FIG. 1)
which includes a depending edge or flange portion 65, which
prevents the insert 15 from passing through the retainer 19, i.e.,
holds the insert 15 in a position wherein the insert 15 is
preferably encased by the retainer 19.
[0029] In the embodiment illustrated, the width "W.sub.1," of the
retainer and the width "W.sub.2" of the insert are selected such
that the face 71 of the insert 15 lies flush with the edge of the
first face 61 of the retainer 19, such that both the insert's face
71 and the edge 61 lie adjacent the flange face 27 in the assembled
state. Thus, in assembly, the retainer 19 "captures" the insert 15
and is then attached to the first hub 13 via a number of fastening
devices such as threaded bolts 73.
[0030] As shown, for example, in FIG. 3, the width W.sub.3 of the
insert mating portion 45 of the second hub 17 is preferably
selected such that its interior face terminates slightly short of
the face of the insert 15. Thus, the second hub 17 does not
protrude through the insert 15 or extend to a point where it might
contact the flange face 27 of the first hub 13.
[0031] In operation in the assembled state (FIG. 4), the insert is
snugly encased and transmits torque and absorbs minor misalignment
without exerting axial thrusts on the cooperating shafts to which
the first and second hubs 13, 17 are respectively attached. Thus,
the insert 17 does not tend to exert forces on the hubs 13, 17
tending to move them parallel to the central axis 75 of rotation in
typical applications. Such forces may cause a hub to move, for
example, 15 thousandths of an inch, which is undesirable or
unacceptable in certain applications.
[0032] FIGS. 5-7 illustrate various design considerations according
to a preferred embodiment of the invention. According to this
illustrated embodiment, the insert 15 exhibits a constant shear
section width d.sub.1. Each exterior lobe, e.g., 33, has respective
flat sides 81 having a selected length d.sub.2 and a central
portion 83 between the two flat sides 81. The central portion 83
has a circular outer contour of radius R.sub.1. Adjacent surfaces
of the drive ring (retainer) 19 are dimensioned to conform to the
shape of the exterior lobe, e.g., 33, for example, in incorporating
flat sections, e.g. 85 adjacent the flat sides 81 of the outer
lobes, the flat sections e.g., 85 having a length d.sub.21. The
width d.sub.3 of each exterior lobe is the same.
[0033] Similar to the exterior lobes, each interior lobe, e.g., 52,
has respective flat sides 87 of equal width d.sub.4 and a central
circular portion 89 connecting those sides 87 and having a radius
R.sub.2. The corner to corner width d.sub.6 of each interior lobe,
e.g., 52, is the same. Finally, the insert includes a split 101 in
one of the outside lobes 33-38 to provide for wraparound
installation.
[0034] An illustrative dimensioning in inches for a coupling of the
size under consideration is as follows: [0035] R.sub.1=1.875 [0036]
R.sub.2=1.625 [0037] d.sub.1=0.500 [0038] d.sub.2=0.730 [0039]
d.sub.2=0.725 [0040] d.sub.3=3.978 [0041] d.sub.4=0.423 [0042]
d.sub.5=0.510 (flat section of hub wings) [0043] d.sub.6=3.325
[0044] R.sub.3=0.100 [0045] R.sub.4=0.100 R.sub.4 and R.sub.3 are
respectively inside corner lobe radii and outside corner hub wing
radii implemented to resist tearing and cutting. As those skilled
in the art will appreciate, the dimensioning of the various widths
and radii illustrated in FIGS. 5-9, of course, varies, for example,
with application and size of a particular coupling. Accordingly, as
those skilled n the art will further appreciate, for example, the
corner to corner width of the interior lobes and/or the exterior
lobes need not all be the same dimension and the exterior lobe and
interior lobe widths could be equal in various embodiments.
[0046] FIG. 6 illustrates various clearances of interest with
respect to a coupling according to embodiment of FIGS. 5-7. The
clearance C.sub.1 is the clearance between the flat sides 87 of the
interior lobes, e.g., 52, and the adjacent surfaces of the central
hub 17. The clearances C.sub.2 are the clearances between the flat
side portions 81 of the exterior lobes, e.g., 33, and the adjacent
flat portions of the retainer 19. The clearances C.sub.5 and
C.sub.60 are the clearances between the outer and inner diameter of
the exterior lobes, e.g., 33, and the retainer 19 and hub 17,
respectively. The clearances C.sub.3 and C.sub.4 are the clearances
between the outer and inner diameter of the interior lobes, e.g.,
52, and the retainer 17 and hub 17, respectively. Illustrative
values in inches for these clearances for a coupling, in which the
outside diameter of the ring 17 is about 14.72 inches, are: [0047]
C.sub.1=0.030 [0048] C.sub.2=0.035 [0049] C.sub.3=0.060 [0050]
C.sub.4=0.060 [0051] C.sub.5=0.060 [0052] C.sub.60=0.060
[0053] FIG. 7 illustrates additional dimensions of interest in an
embodiment according to FIG. 5. In particular, dimension C.sub.8
represents the thickness of that part 65 of the retainer 19 which
overlaps the insert 15. Dimension C.sub.7 represents the clearance
range between the opposing faces of the driving and driven hubs 17,
13. The clearance C.sub.6 represents the distance by which the face
of the driving hub 17 is set back from the face of the insert 15.
Dimension C.sub.9 represents the clearance between the side face of
the insert 15 and the interior edge of the retainer ring 19.
Dimension C.sub.10 represents the clearance range between the face
of the insert 15 and the driven hub 13. Representative dimensions
in inches for an illustrative coupling of the size under discussion
are: [0054] C.sub.6=0.0200 [0055] C.sub.7=0.090-.310 [0056]
C.sub.8=0.5000 [0057] C.sub.9=0.0200 [0058]
C.sub.10=0.0200-.2700
[0059] Several observations may be made with respect to operation
of the couplings according to various embodiments disclosed herein.
First, the flat side surfaces on the interior and exterior lobes
facilitate torque transmission. The coupling further provides free
axial float, illustrated, for example, by clearance ranges C.sub.7
and C.sub.10 in FIG. 7, as well as relatively wider width W.sub.2
of the insert and relatively wider wings W.sub.3 of the hub, for
example, when compared to features of previous couplings such as
ATR Sales' "A" or "M" series. In particular applications, the
design enables the driving and driven shafts to be positioned at
greater distances from one another than previous designs. In such
case, for example, greater thermal growth of shafts can be
accommodated than in previous systems.
[0060] FIG. 8 illustrates an alternate and improved insert 150
captured by an outer retainer member 190 and receiving a second hub
170. The insert 150 features exterior lobes 133, 134, 135, etc. and
interior lobes 152, 153, 154, etc., which are generally disposed in
the same fashion as the respective exterior and interior lobes of
the insert 15 (e.g. FIG. 1) but which are contoured differently. In
particular, each lobe 133, 134, 135 has two equal-length straight
or flat side segments, e.g., 201, 202, leading to respective
segments 203, 204 of a common radius. Respective ends of the two
radiused segments are joined by a central circumferentially lying
segment 205. The central segment 205 may be either a straight or
slightly curved. This construction provides a locking effect which
positively locates the rotating parts under load to limit twist and
to increase torsional stiffness and stability. It is desirable to
provide as much flat side area, e.g. 201, as possible because these
areas provide the driving surfaces of the coupling, while the
radiused corners 203, 204 provide resistance which assists in
preventing the exterior and interior lobes from coming out of their
respective mounting wells when under stress of operation.
[0061] FIG. 9 provides an enlarged view of a portion of the
coupling structure of FIG. 8. For the particular coupling
illustrated, the space S.sub.1 between the side of each interior
lobe, e.g. 152, and the adjacent side of each spoke of the inner
hub 170 may be, for example, 0.060 inches, while the space S.sub.2
between each side of each lobe, e.g. 133, and each adjacent face of
the retainer 190 may be 0.035 inches, for a coupling where the
segments of the inner lobes of the insert lie tangent to a circle
13.652 inches in diameter. The angle .alpha. between the flat or
straight sides of each inner lobe is 60 degrees in the particular
illustrative embodiment. Such dimensioning is of course
illustrative and will vary with various embodiments as discussed
above. Additionally, it may be noted that smaller coupling sizes
may not be ideally suited to the use of inserts having the
alternate design shown in FIGS. 8 and 9.
[0062] FIG. 10 and 11 illustrate an alternate embodiment wherein an
insert 150 is split at three locations so as to form three separate
insert section 161, 162, 163. The particular illustrated splits
shown in this illustrative embodiment are located at the mid-point
(radial centerline) of a respective outer lobe, e.g. 152.
Segmenting an insert 150 as shown in FIGS. 10 and 11 lowers the
effects of hysteresis, permitting the segmented insert 150 to run
cooler and prolonging its life. While FIGS. 10 and 11 illustrate an
insert divided into three segments, more or less than three
segments could be used in various embodiments.
[0063] FIG. 12 illustrates an alternative embodiment where two
inserts 15 are arranged to be mounted adjacent one another on
extended wings 218 of an inner or second hub 217. An axially
lengthened retainer, 219 then captures the two inserts 15 and
attaches to the face of another hub 13 in the manner generally
illustrated in FIG. 1. This design doubles torque handling
capability without increasing the diameter of the coupling, which
proves useful in applications where space is limited. More than two
adjacently mounted inserts may also be provided.
[0064] Couplings as disclosed above have the advantage of combining
advantageous aspects of both shear and compression couplings. In
particular, the disclosed couplings normally operate in
compression, which prevents exertion of axial thrusts, but can
still shear to protect equipment in the event of lock-up or
overload, etc. An example is the case of shredding apparatus used
to shred recycled material. Occasionally, the material will include
prohibited foreign objects which can lock the shredder. In such
case, the insert of a coupling according to the disclosed design
will shear rather than break the associated equipment.
[0065] While the present invention has been described above in
terms of specific embodiments, it is to be understood that the
invention is not limited to the disclosed embodiments. The role of
"driving" and "driver hubs" may be reversed and dimensioning
adapted to particular sizes and conditions. Thus, the present
invention is intended to cover various modifications and equivalent
methods and structures included within the spirit and scope of the
appended claims.
* * * * *