U.S. patent application number 11/584791 was filed with the patent office on 2007-02-15 for tripod joint.
Invention is credited to Juergen Henkel, Peter Muenich, Rolf Schroeder, Guenter Woerner.
Application Number | 20070037627 11/584791 |
Document ID | / |
Family ID | 7696424 |
Filed Date | 2007-02-15 |
United States Patent
Application |
20070037627 |
Kind Code |
A1 |
Henkel; Juergen ; et
al. |
February 15, 2007 |
Tripod joint
Abstract
A ball body is guided in a partially cylindrical hole into which
a guide ring is inserted to secure it axially and to guide the
pivoting movement. The tripod joint is suitable for the
displaceable and pivotable driving connection of two shaft ends, in
particular in conjunction with drive trains or side shafts of motor
vehicles.
Inventors: |
Henkel; Juergen; (Kernen,
DE) ; Muenich; Peter; (Fellbach, DE) ;
Schroeder; Rolf; (Stuttgart, DE) ; Woerner;
Guenter; (Kernen, DE) |
Correspondence
Address: |
KENYON & KENYON LLP
ONE BROADWAY
NEW YORK
NY
10004
US
|
Family ID: |
7696424 |
Appl. No.: |
11/584791 |
Filed: |
October 20, 2006 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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10227034 |
Aug 23, 2002 |
7125339 |
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11584791 |
Oct 20, 2006 |
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Current U.S.
Class: |
464/111 |
Current CPC
Class: |
Y10T 403/32663 20150115;
F16C 29/04 20130101; F16C 2361/41 20130101; F16D 3/2055 20130101;
F16D 2003/2023 20130101; F16C 33/306 20130101 |
Class at
Publication: |
464/111 |
International
Class: |
F16D 3/26 20060101
F16D003/26 |
Foreign Application Data
Date |
Code |
Application Number |
Aug 23, 2001 |
DE |
101 41 427.7 |
Claims
1. A tripod joint for transmitting a driving torque between two
driving elements of a drive train, comprising: a joint inner part;
and a joint outer part holding the joint inner part, the joint
inner part having a tripod star including ball bodies with pins,
the ball bodies in each case mounted in a recess in a pressure body
pivotable with respect to the pressure body, the pressure body and
a rolling body configured to transmit the driving torque to the
joint outer part, the recess in the pressure body including a
cylindrical subregion, at least one guide ring inserted into the
pressure body in a region of a cylindrical subregion, a ball body
supported with respect to the pressure body via the guide ring.
2. The tripod joint according to claim 1, wherein the recess
includes a subregion corresponding to a cutout from a hemisphere
and a cylindrical subregion, a guide ring arranged in the
cylindrical subregion.
3. The tripod joint according to claim 1, wherein the recess
includes a cylindrical hole, two spaced apart guide rings inserted
into the cylindrical hole.
4. The tripod joint according to claim 1, wherein the guide rings
include a curved and smooth cross-section at least in a region
facing the ball body.
5. The tripod joint according to claim 1, wherein the cylindrical
subregion includes grooves, the guide rings inserted into the
grooves.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application claims foreign priority to
Application No. 101 41 427.7, filed on Aug. 23, 2001 in the Federal
Republic of Germany, which is expressly incorporated herein in its
entirety by reference thereto.
FIELD OF THE INVENTION
[0002] The present invention relates to a tripod joint.
BACKGROUND INFORMATION
[0003] Tripod joints are used, for example, as side shafts of motor
vehicles. The tripod joints are used for transmitting driving
torques between two driving elements of a drive train. The tripod
joints allow a relative displacement and a relative pivoting of the
driving elements to be compensated for. In the case of side shafts
of a motor vehicle, relative movements of this type are caused by
spring deflections of the vehicle wheels.
[0004] U.S. Pat. No. 4,619,628 describes a tripod joint having a
joint outer part and a joint inner part held in the latter. The
joint inner part has a tripod star having ball bodies having pins.
The ball bodies are accommodated pivotably in a partially spherical
universal ball joint of a pressure element and are therefore
mounted pivotably with respect to the pressure element. The
pressure element is mounted movably via rolling bearings with
respect to the mating surfaces of the joint outer part.
[0005] The production of the recess in the pressure element for the
purpose of forming the universal ball joint requires a high
manufacturing outlay. In order to realize extensive bearing
surfaces of the pressure element on the ball body, a curved surface
is required to be manufactured with great precision. The
installation of the ball body in the pressure element constitutes a
further problem. Conventionally, a configuration of the connection
as a bayonet connection is required for this purpose.
SUMMARY
[0006] It is an object of the present invention to provide a
different connection configuration, which may ensure pivoting,
between the pressure element and ball body of a tripod joint.
[0007] The above and other beneficial objects of the present
invention are achieved by providing a tripod joint as described
herein.
[0008] The recess in the pressure body is configured with a
cylindrical subregion. The latter may be manufactured with great
precision in a simplified manner in comparison to a spherical
surface. At least one guide ring is inserted into the pressure body
in the region of the cylindrical subregion. This enables the
installation options to be expanded. Furthermore, the guide ring
may be manufactured from a different material than the pressure
body. For example, a, e.g., more expensive, material having
improved sliding properties may be used in the region of the at
least one guide ring. The ball body is supported with respect to
the pressure body via the guide ring. When the guide ring is
removed, removal of the pressure element from the ball body may
take place, for example. Complex bayonet connections are therefore
rendered superfluous. The installation of the pressure body
together with the ball body does not require any rotating movement
as in the case of a bayonet connection. Furthermore, defined
contact regions--in contrast to extensive bearing surfaces--for the
transmission of force between the ball body and pressure body may
be predetermined by the guide rings.
[0009] In one example embodiment of the present invention, the
recess is configured as a cylindrical hole into which two spaced
apart guide rings are inserted. In order to manufacture this
example embodiment, the hole and the grooves have merely to be made
in the pressure element. The guide rings may be produced in large
piece numbers.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] FIG. 1 is a longitudinal cross-sectional view of a tripod
joint.
[0011] FIG. 2 is a cross-sectional view of a tripod joint.
[0012] FIG. 3 is a cross-sectional view of a joint pin with
pressure body, cage, rolling bodies and centering elements taken
along the line A-A illustrated in FIG. 2.
[0013] FIG. 4 is a cross-sectional view of a joint pin according to
the present invention with pressure element, guide ring, moving
cage and rolling bodies taken transversely with respect to
longitudinal axis 13-13.
[0014] FIG. 5 is a cross-sectional view of a further joint pin
according to the present invention with pressure element, guide
ring, moving cage and rolling bodies taken transversely with
respect to longitudinal axis 13-13.
[0015] FIG. 6 is a cross-sectional view of a further joint pin
according to the present invention with pressure element, guide
ring, moving cage and rolling bodies taken transversely with
respect to longitudinal axis 13-13.
DETAILED DESCRIPTION
[0016] A tripod joint 10 has a joint inner part 11 and a joint
outer part 12 holding the latter. The joint inner part 11 and the
joint outer part 12 are in each case connected, at least in a
rotationally fixed manner, to a driving element of a drive train of
a motor vehicle, for example to a drive shaft and a vehicle wheel.
The tripod joint 10 is used to transmit a driving torque between
the joint inner part 11 and the joint outer part 12 while ensuring
a relative displacement along the longitudinal axis 13-13 of the
joint inner part 11 and-along the longitudinal axis 14-14 of the
joint outer part 12, a relative pivoting of the joint inner part 11
with respect to the joint outer part 12, which pivoting is
associated with a change in the angle 15 between the longitudinal
axes 13-13 and 14-14, and a three-dimensional movement which arises
from a combination of the abovementioned forms of movement.
[0017] The joint inner part 11 has, at the end on the inside, three
pins 16 which are formed as a single piece or a number of pieces
together with the latter, are orientated radially and are
distributed in each case at 120.degree. in the circumferential
direction and form a tripod star. The pins 16 have in each case a
partially spherical ball body 17. In order to transmit forces in
both circumferential directions, the ball body 17 bears, in each
case in the region of the spherical lateral surface, against a
correspondingly configured recess 18 of a pressure element 19. On
the opposite side of the pressure element 19, which side faces a
flat mating surface 20 of the joint outer part 12, the pressure
element is of flat configuration with a running surface 21.
[0018] The running surface 21 and the mating surface 20 are
orientated parallel to each other. Cylindrical rolling bodies 23,
in particular rollers or needles, are held between the latter
forming a linear contact. A plurality of rolling bodies are guided
in a cage 24 in such a manner that the relative position of the
longitudinal axes of the rolling bodies with respect to the cages
does not change substantially. In order to transmit circumferential
forces in the opposite direction, each pin 16 is configured with
two associated pressure elements 19, the rolling bodies 23 and the
surfaces 20, 21 symmetrically to a pin central plane accommodating
the longitudinal axis 13-13.
[0019] The running surface 21 of a pressure element 19 may have a
rectangular form, with the result that as many rolling bodies 23 as
possible form a load-bearing contact with the surface pressure
being reduced. However, circular or oval pressure elements 19 are
also possible.
[0020] The joint outer part 12 has a recess.25 orientated in the
direction of the longitudinal axis 14-14 with an essentially
circular, central hole 26 and three holding spaces 27 which are
orientated radially and are distributed in each case at 120.degree.
C. in the circumferential direction and are used in each case for
holding and supporting a pin 16, two pressure elements 19 and
rolling bodies 23. In the section illustrated in FIG. 2, the
holding spaces 27 have an essentially U-shaped contour open in the
direction of the hole 26, the side limbs of the U-shaped contour
being formed with the mating surfaces 20. In the exemplary
embodiment illustrated in FIG. 2, the side limbs are of rectilinear
configuration without a transitional region to the mating surfaces
20. In the direction of the hole 26, the side limbs do not, in
particular, have any projections or depressions, but rather merge
into the hole 26 in the end region on the inside with an
enlargement of the spacing. In the position of the tripod joint
illustrated in FIG. 2, the rolling bodies together with the cage
are arranged spaced apart radially from the main limb of the
U-shaped contour.
[0021] As illustrated in FIG. 2, the rolling bodies 23 are guided
in a cage 24. The rolling bodies 23 are guided in the cages 24 with
the relative position of the longitudinal axes 31 of the rolling
bodies 23 with respect to each other being ensured. The cages 24
are guided in the radial direction with respect to the pressure
element 19 over shoulders 32 engaging around and enclosing the
pressure element 19 (FIGS. 4 to 6). The cages 24 may be "clipped"
via the shoulders 32 onto the pressure element 19, as illustrated.
The cages 24 may furthermore be centered in the running direction
of the rolling bodies 23 via centering or spring elements 33. Two
cages 24 of a pin 16 may be guided and centered via a common spring
element 33.
[0022] For both circumferential directions, the pressure elements
19 assigned to a ball body 17 are connected via two connecting webs
34 to form a pressure body 29 configured as a single piece.
According to the example embodiment illustrated in FIG. 3, an
introduction of the ball body 17 into the single-piece pressure
body 29 may be ensured by a configuration, e.g., a bayonet
connection.
[0023] According to the exemplary embodiment illustrated in FIGS. 2
and 3, two spring elements 33 are connected to the pressure body 29
or the ball body 17 via a respective fastening arrangement 36. The
spring elements 33 in each case have two elastic fingers 37 which
bear against the opposite cages 24 or are connected thereto, for
the purpose of supporting them.
[0024] In comparison with the ball body 17, the cage 24 having the
rolling bodies has, in particular, just two degrees of freedom: a
suitably selected connection of the ball body 17 to the pressure
body 29 may ensure pivotability about an axis perpendicular with
respect to the plane defined by the longitudinal axis 13-13 of the
joint inner part 11 and the longitudinal axis of the pins 16. The
second degree of freedom is the connection between the cage 24 and
pressure body 29, which connection may be displaced in a
translatory manner. In order to ensure the pivotability of the
pressure body 29 with respect to the ball body 17, as illustrated
in FIG. 3 the pressure element 29 may hold the ball body 17 in a
universal ball joint.
[0025] In a departure from the previously illustrated form of
holding in a universal ball joint, according to the present
invention, holding occurs as illustrated in FIGS. 4 to 6.
[0026] According to the exemplary embodiment illustrated in FIG. 4,
the recess 18 in the pressure body 29 has a first, cylindrical
subregion 40 and a subregion 41 which is adjacent to the latter and
corresponds essentially to a subsurface of a hemisphere. In the
region of the subregion 41, the latter bears extensively against
the ball body 17. Spaced apart from the transitional region from
the cylindrical subregion 40 to subregion 41, the cylindrical
subregion has a groove 42 into which a guide ring 43 is inserted,
in particular with radial expansion. Radially on the inside, the
guide ring 43 bears against the ball body 17.
[0027] As illustrated in FIG. 4, the subregion 41 is arranged
between the cylindrical subregion 40 and the central point of the
tripod star while, as illustrated in FIG. 5, the cylindrical
subregion 40 is arranged between the subregion 41 and the central
point of the tripod star.
[0028] An example embodiment of the present invention which may be
simple to produce is illustrated in FIG. 6: the recess 18 is, e.g.,
completely, configured cylindrically in the form of a hole 44 and
has two spaced apart grooves 42 with guide rings 43. In this case,
in the center of the two grooves 42 the ball body 17 bears against
the hole 44 and against contact surfaces of the guide rings 43
radially on the inside. In the case of guide rings 43 having a
different radial extent, the contact region of the ball body 17 may
be displaced with the hole 44 out of the center in the direction of
the guide ring 43 having a smaller radial extent. It is possible
for the ball body 17 to bear only against the two guide rings 43 or
against a third guide ring in the center.
[0029] The guide rings 43 may be manufactured from a material
having good sliding properties, for example brass. The guide rings
43 have, in particular, a rectangular, circular or oval
cross-section or, in the region facing the ball body 17, have a
cross-sectionally concave curvature, in particular with the radius
of the ball body 17. At least one guide ring 43 may be connected
fixedly to the pressure body 29. For example, a guide ring 43 as
illustrated in FIG. 6 is manufactured as an inner step of the
recess 18 of the pressure body 19 or is connected to the latter
with a cohesive material joint. Other forms of connecting the guide
rings 43 to the pressure body 29, in particular form-fitting or
frictional forms or forms with a cohesive material joint are
possible. For example, at least one guide ring 43 may have an outer
thread by which the guide ring 43 may be screwed into the pressure
body.
[0030] Instead of the single-piece pressure body 29 illustrated in
FIGS. 4 to 6, the latter may be formed in a number of pieces, in
particular with two separate pressure elements 19.
[0031] The configuration according to the present invention may be
suitable for any arrangement of a tripod joint, in particular those
based on a ball body 17 guided in a universal ball joint.
[0032] The example embodiments described involve configurations
only given by way of example. A combination of the described
features for different example embodiments is possible. Further
features, in particular features which have not been described, of
the device parts belonging to the invention are to be taken from
the device-part geometries illustrated in the drawings.
* * * * *