U.S. patent application number 10/770191 was filed with the patent office on 2005-04-28 for counter track joint with improved cage.
Invention is credited to Hassenrik, Ida, Maucher, Stephan, Weckerling, Thomas.
Application Number | 20050090317 10/770191 |
Document ID | / |
Family ID | 32730692 |
Filed Date | 2005-04-28 |
United States Patent
Application |
20050090317 |
Kind Code |
A1 |
Hassenrik, Ida ; et
al. |
April 28, 2005 |
Counter track joint with improved cage
Abstract
A counter track joint having an outer joint part (10), inner
joint part (20), a ball cage (30) and torque transmitting balls.
First outer tracks and first inner tracks form first pairs of
tracks which widen in a first direction, and second outer tracks 12
and second inner tracks form second pairs of tracks which widen in
an opposed second direction. The annular cage (30) includes four
first and four second circumferentially distributed cage windows
which each accommodate one of the balls and which hold the balls in
one plane. The second outer ball tracks (12), at one end, include
widened assembly portions (13) for inserting balls (32) into the
second cage windows from the radial outside, with all the first
cage windows already having balls, and with the second cage windows
axially projecting from the outer joint part (10) as a result of
the joint being over-articulated.
Inventors: |
Hassenrik, Ida; (Troisdorf,
DE) ; Maucher, Stephan; (Siegburg, DE) ;
Weckerling, Thomas; (Lohmar, DE) |
Correspondence
Address: |
Robert P. Renke
Suite 250
28333 Telegraph Road
Southfield
MI
48034
US
|
Family ID: |
32730692 |
Appl. No.: |
10/770191 |
Filed: |
February 2, 2004 |
Current U.S.
Class: |
464/145 |
Current CPC
Class: |
F16D 2003/22303
20130101; Y10S 464/906 20130101; F16D 2003/22306 20130101; F16D
3/223 20130101; Y10T 29/49826 20150115 |
Class at
Publication: |
464/145 |
International
Class: |
F16D 003/16 |
Foreign Application Data
Date |
Code |
Application Number |
Feb 3, 2003 |
DE |
103 04 156.7 |
Claims
1. A counter track joint comprising: an outer joint part having
four first outer tracks and four second outer tracks which
alternate and are uniformly circumferentially distributed; an inner
joint part having four first inner tracks and four second inner
tracks which alternate and are uniformly circumferentially
distributed, the first outer tracks and the first inner tracks
forming first pairs of tracks which, when the joint is in the
aligned condition, widen in a first direction (R1), and the second
outer tracks and the second inner tracks forming second pairs of
tracks which, when the joint is in the aligned condition, widen in
an opposite direction (R2); eight torque transmitting balls each
held in respective first and second pairs of tracks; and a ball
cage having four first and four second circumferentially
distributed cage windows which each accommodate one of the balls
and hold the balls, as a group, in one plane by way of their
centers; wherein at a first aperture of the outer joint part, the
second outer tracks comprise widened assembly regions for inserting
the balls into the second cage windows from the radial outside,
while the first cage windows are already fully filled with balls
and with second cage windows axially projecting from the outer
joint part as a result of the joint being over-articulated.
2. A counter track joint according to claim 1, wherein the four
first cage windows associated with the first pairs of tracks
comprise a greater length (L1) in the circumferential direction
than the four second cage windows which are associated with the
second pairs of tracks and comprise a length (L2) which is adapted
to the operating angle of articulation of the joint.
3. A counter track joint according to claim 1, wherein the first
cage windows comprise a circumferential length (L1) which
corresponds to the length (L2) of the second cage windows, and
wherein the lengths (L1, L2) are adapted to the operating angle of
articulation of the joint and include an excess dimension.
4. A counter track joint according to claim 1, wherein the outer
joint part includes a base at its end which is axially opposed to
the first aperture.
5. A counter track joint according to claim 2, wherein the outer
joint part includes a base at its end which is axially opposed to
the first aperture.
6. A counter track joint according to claim 3, wherein the outer
joint part includes a base at its end which is axially opposed to
the first aperture.
7. A joint according to claim 1, wherein the inner joint part is
adapted to removably receive a driveshaft.
8. A joint according to claim 2, wherein the inner joint part is
adapted to removably receive a driveshaft.
9. A joint according to claim 3, wherein the inner joint part is
adapted to removably receive a driveshaft.
10. A joint according to claim 4, wherein the inner joint part is
adapted to removably receive a driveshaft.
11. A counter track joint according to claim 1, wherein the outer
joint part comprises a second aperture at its end which is axially
opposed to the first aperture.
12. A counter track joint according to claim 2, wherein the outer
joint part comprises a second aperture at its end which is axially
opposed to the first aperture.
13. A counter track joint according to claim 3, wherein the outer
joint part comprises a second aperture at its end which is axially
opposed to the first aperture.
14. A counter track joint according to claim 11, comprising a
driveshaft connected to the inner joint part and wherein the inner
joint part, toward the end of the first aperture, comprises
inwardly recessed track run-outs for the second inner tracks.
15. A counter track joint according to claim 12, comprising a
driveshaft connected to the inner joint part and wherein the inner
joint part, toward the end of the first aperture, comprises
inwardly recessed track run-outs for the second inner tracks.
16. A counter track joint according to claim 13, comprising a
driveshaft connected to the inner joint part and wherein the inner
joint part, toward the end of the first aperture, comprises
inwardly recessed track run-outs for the second inner tracks.
17. A counter track joint comprising: an outer joint part having
alternating and uniformly circumferentially distributed first outer
tracks and second outer tracks; an inner joint part having
alternating and uniformly circumferentially distributed first inner
tracks and second inner tracks, the first outer tracks and first
inner tracks forming first pairs of tracks which, when the joint is
aligned, widen in a first direction (R1), the second outer tracks
and second inner tracks forming second pairs of tracks which, when
the joint is aligned, widen in an opposite direction (R2); eight
balls; and a ball cage having four first and four second
circumferentially distributed cage windows which each accommodate a
ball and hold the balls in a common plane in the first and second
pairs of tracks, wherein, at an aperture of the outer joint part,
the second outer tracks comprise widened assembly regions for
inserting the balls into the second cage windows from the outside
while the first cage windows already contain balls, and second cage
windows axially project from the outer joint part while the joint
is over-articulated.
18. A counter track joint according to claim 17, wherein the four
first cage windows comprise a circumferential length (L1), and the
four second cage windows comprise a circumferential length (L2)
which is adapted to the operating angle of articulation of the
joint, and L1 is greater than L2.
19. In a counter track joint comprising an outer joint part having
alternating and uniformly circumferentially distributed first outer
tracks and second outer tracks; an inner joint part having
alternating and uniformly circumferentially distributed first inner
tracks and second inner tracks, the first outer tracks and first
inner tracks forming first pairs of tracks which, when the joint is
aligned, widen in a first direction (R1), the second outer tracks
and second inner tracks forming second pairs of tracks which, when
the joint is aligned, widen in an opposite direction (R2); eight
balls; and a ball cage having four first and four second
circumferentially distributed cage windows which each accommodate a
ball and hold the balls in a common plane in the first and second
pairs of tracks, a method of assembling the counter track joint
comprising: providing a widened assembly region in the second outer
tracks at an aperture of the outer joint part; over-articulating
the joint about a first axis; thereafter, inserting a ball into
each of the first cage windows; thereafter, over-articulating the
joint about a second axis; and thereafter, inserting a ball into
each of the second cage windows while second cage windows axially
project from the outer joint part.
20. A method according to claim 19, wherein the first cage windows
comprise a circumferential length (L1), and the second cage windows
comprise a circumferential length (L2) which is adapted to the
operating angle of the joint, and L1 is greater than L2.
21. A method according to claim 19, wherein the first and second
cage windows comprise equal circumferential lengths (L1, L2) each
adapted to the operating angle of the joint and include an excess
dimension.
Description
TECHNICAL FIELD
[0001] The present invention relates to constant velocity joints
and, more particularly, concerns constant velocity joint assemblies
having improved construction.
BACKGROUND OF THE INVENTION
[0002] Constant velocity fixed ball joints in the form of counter
track joints, have an outer joint part with outer tracks, an inner
joint part with inner tracks, torque transmitting balls which are
received in pairs of tracks consisting of outer tracks and inner
tracks, and a ball cage with cage windows in which the balls are
held in a common plane and are guided on to the angle-bisecting
plane when the joint is articulated. In such joints, first outer
tracks, together with first inner tracks, form first pairs of
tracks whose control angles open in a first axial direction, and
second outer tracks, together with second inner tracks, form second
pairs of tracks whose control angles open in a second axial
direction. The control angles are defined as angles between the
tangents at the ball contact points in the tracks when the joint is
in the aligned condition. The present invention concerns counter
track joints having four first outer tracks and four second outer
tracks which alternate and are uniformly circumferentially
distributed. In the inner joint part, there are provided four first
inner tracks and four second inner tracks which alternate and are
uniformly circumferentially distributed. The first outer tracks and
the first inner tracks, together, form first pairs of tracks which,
when the joint is in the aligned condition, widen in a first
direction. The second outer tracks and the second inner tracks,
together, form second pairs of tracks which, when the joint is in
the aligned condition, widen in an opposite direction. A ball is
held in each of the pairs of tracks. The annular cage comprises
eight circumferentially distributed cage windows which each
accommodate one of the balls and hold the balls, in their entirety,
in a common plane by means of their centers.
[0003] Counter track joints, in general, are known from DE 100 60
119 A1 of the applicant, wherein the counter track joints are
illustrated and described as having six torque transmitting balls.
Rzeppa fixed joints with identical pairs of tracks with six torque
transmitting balls wherein, for assembly reasons, the cage windows
have different circumferential lengths, are described in U.S. Pat.
No. 5,509,856 also owned by the application herein. From JP
2001232945A there are known Rzeppa fixed joints with identical
pairs of tracks which comprise eight balls and wherein at the outer
ball tracks, at the aperture end, there are provided assembly
pockets for inserting balls when the joint is over-articulated.
[0004] There are certain disadvantages associated with the assembly
of constant velocity joints wherein first the outer joint part,
cage and inner joint part are joined in one of the ways commonly
known. That is, typically, the balls are inserted by
over-articulating the joint, i.e. articulating the inner joint part
and cage relative to the outer joint part, thus enabling a cage
window of the ball cage to project from the outer joint part and
permitting a ball to be inserted into the cage window from the
radial outside. When the cage windows are already largely filled
with balls, the so-called method of over-articulating--because of
the relative circumferential movement of the balls in the cage
relative to one another--requires a circumferential cage window
length which is needed during assembly only, but not under
operational conditions of the joint. In other words, the maximum
operating angle of articulation does not dictate the cage window
length. Rather, the extended cage window length is necessary only
for assembly. Such lengthening of the cage windows in the
circumferential direction leads to a reduction in the web width
between the cage windows in the circumferential direction, and thus
to a weakening of the ball cage. Experience shows that, in
operation, the cage constitutes a potentially frangible component
which should be designed so as to be as strong as possible. Thus,
there exists a need for an eight-ball counter track joint having
improved cage strength or durability.
SUMMARY OF THE INVENTION
[0005] The present invention provides a counter track joint with
eight balls wherein the strength of the cage has been increased as
compared to known designs. In particular, the present joint
provides that, at an aperture of the outer joint part, the second
outer ball tracks of the outer joint part comprise widened assembly
regions for inserting second balls into second cage windows from
the radial outside, while the first cage windows are already fully
filled with first balls and with the second cage windows axially
projecting from the outer joint part as a result of the joint being
over-articulated.
[0006] According to a particular embodiment, four first cage
windows associated with the first pairs of tracks comprise a
greater length (L1) in the circumferential direction than four
second cage windows which are associated with the second pairs of
tracks and comprise a length (L2) which is adapted to the operating
angle of articulation of the joint.
[0007] As a result of the inventive widened assembly regions at the
ends of the second outer ball tracks, it is possible to insert the
balls of a second group of balls when the cage is articulated only
slightly beyond the maximum operating angle of articulation
relative to the outer joint part. Advantageously, the first cage
windows for an already inserted first group of balls need to be
increased only slightly beyond their circumferential length
required for operational purposes. The cage windows for the second
group of balls can comprise a shorter circumferential length
because the balls inside these windows are not displaced relative
to one another during assembly. During assembly, as the balls of
the second group are positioned on the articulation axis of the
joint on the one hand, and on the articulation plane of the joint
on the other hand, they merely require the minimum length needed
for articulation purposes within the operating range of
articulation. It is thus possible to widen the webs between the
cage windows considerably, thereby increasing the strength of the
cage in operation. The load bearing capacity of the inventive joint
is thus also increased.
[0008] According to a further advantageous embodiment which
requires particularly large widened assembly regions, four first
cage windows associated with the first pairs of tracks, comprise a
length L1 in the circumferential direction which corresponds to the
length L2 of four second cage windows associated with the second
pairs of tracks. The lengths are adapted to the operating angle of
articulation of the joint, but include only a small excess
dimension. In this embodiment, the assembly process is the same as
described above, with one advantage being that the cage can be
inserted as desired, relative to the first and second pairs of
tracks.
[0009] According to another advantageous embodiment which is also
illustrated, the outer joint part is provided with a base, at its
end which is axially opposed to the aperture. More particularly, a
driveshaft can be removably inserted into the inner joint part in
this embodiment.
[0010] According to a further embodiment which is also illustrated,
a driveshaft is firmly connected to the inner joint part and, at
the end of the aperture, the inner joint part comprises inwardly
recessed track run-outs for the second inner tracks.
[0011] Other advantages and features of the invention will also
become apparent upon reading the following detailed description and
appended claims, and upon reference to the accompanying
drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] For a more complete understanding of this invention,
reference should now be made to the embodiments illustrated in
greater detail in the accompanying drawings and described below by
way of examples of the invention.
[0013] FIG. 1 shows an inventive joint in a first embodiment:
[0014] A) in an axial view of the joint aperture;
[0015] B) in a section A-A according to FIG. 1A; and
[0016] C) in a longitudinal section B-B according to FIG. 1A.
[0017] FIG. 2 shows the inventive joint according to FIG. 1 while
the first group of balls is being assembled:
[0018] A) in an axial view of the outer joint part;
[0019] B) in section B-B according to FIG. 2A; and
[0020] C) with the cage shown in the form of an enlarged
detail.
[0021] FIG. 3 shows the inventive joint while the second group of
balls is being assembled:
[0022] A) in an axial view of the outer joint part;
[0023] B) in the longitudinal section A-A according to FIG. 3A with
an enlarged detail X; and
[0024] C) in the cross-section F-F through the ball cage according
to FIG. 3B.
[0025] FIG. 4 shows a joint according to the state of the art while
the second group of balls is being assembled:
[0026] A) in an axial view of the outer joint part;
[0027] B) in the longitudinal section A-A of FIG. 4A; and
[0028] C) in the cross-section F-F through the ball cage according
to FIG. 4B.
[0029] FIG. 5 shows an inventive joint in a second embodiment in
the form of a disc joint:
[0030] A) in an axial view of the joint; and
[0031] B) in a longitudinal section through the joint.
[0032] FIG. 6 shows the joint according to FIG. 5 during the
assembly of the second group of balls, with an enlarged detail
X.
DETAILED DESCRIPTION OF THE DRAWINGS
[0033] In the following figures, the same reference numerals are
used to refer to the same components in the various views. Also, in
the following description, various operating parameters and
components are described for several embodiments. These parameters
and components are included as examples and are not meant to be
limiting.
[0034] The three individual illustrations of FIG. 1 will be
described jointly below. The figures illustrate a constant velocity
fixed ball joint and, more particularly, a counter track joint with
eight balls. In the embodiment illustrated here, an outer joint
part 10 comprises a joint aperture 17 and a base 18 with a
formed-on journal 19. The outer joint part 10 is provided with
first outer ball tracks 11 and second outer ball tracks 12, each
having four ball tracks being alternately distributed across the
circumference. The outer joint part 10 accommodates a ball cage 30
and in inner joint part 20. In the inner joint part 20, first inner
ball tracks 21 and second inner ball tracks 22 are alternately
circumferentially distributed in the form of four ball tracks each.
First outer ball tracks 11 and first inner ball tracks 21 form
first pairs of tracks 11, 21. Second outer ball tracks 12 and
second inner ball tracks 22 form second pairs of tracks 12, 22.
With the joint being in the aligned condition, the first pairs of
tracks 11, 21 widen from the aperture 17 towards the base 18 in a
first direction R1. The second pairs of track 12, 22, when the
joint is in the aligned condition, widen from the base 18 to the
aperture 17 in a second direction R2. The first pairs of tracks 11,
21 hold balls 31 of a first group of balls. The second pairs of
tracks 12, 22 hold balls 32 of a second group of balls. The balls
are held by a ball cage 30 in a common plane, namely in
circumferentially extending cage windows (not illustrated in
detail) in the ball cage 30.
[0035] Below, the individual illustrations of FIG. 2 will be
described jointly. FIG. 2 shows the joint of FIG. 1 during the
conventional method of assembling the four balls 31 of the first
group of balls by over-articulating the joint. To clarify the
conditions and simplify the drawing, the inner joint part is not
shown. The outer joint part 10 is shown in the sectional plane B-B
of the first outer ball tracks 11. In the sectional plane, the ball
cage 30 is articulated by an angle .alpha. relative to the outer
joint part 10. The inner joint part (not illustrated) is
articulated by the same angle .alpha. in the same plane relative to
the ball cage 30. Three of the balls 31 have already been mounted
in the way illustrated here. In the position as illustrated, the
upper ball 31 positioned in the sectional plane can be inserted
into a first cage window 27 projecting from the outer joint part
10. The first cage windows 27 alternate across the circumference
with the second cage windows 28 which are dimensioned differently
in the circumferential direction. As compared to the diameter of
the balls of the first ball group 31, the cage windows 27 comprise
an assembly play of 2a in the circumferential direction. The
assembly play is sufficient for inserting the balls 32 of the
second group of balls at a later stage by over-articulating the
joint, as shown here, after the balls 31 of the first group of
balls have already been inserted. The interesting aspect here is
the insertion, as shown here, of the last one of the four balls 31
of the first group of balls, in the case of which last ball the
ball cage 30 has been rotated around a transverse axis 14 relative
to the outer joint part by the angle .alpha., with the inner joint
part (not illustrated here) being rotated once more by an angle
.alpha. of the same size in the same direction relative to the ball
cage 30 around the transverse axis 14.
[0036] In FIG. 3, the individual illustrations will be described
jointly below. FIG. 3 shows the joint of FIG. 1 during assembly of
the fan balls 32 of the second group of balls. The inventive joint
is shown in the section A-A through the second outer ball tracks 12
of the outer joint part 10 while the balls 32 of the second group
of balls are being mounted. The balls 31 of the first group of
balls have already been inserted in accordance with the previous
Figure. Again, for reasons of clarity, the inner joint part is not
illustrated. The cage 30 is articulated relative to the outer joint
part 10 by an angle .beta.2 around a second transverse axis 15
rotated relative to the first transverse axis 14 by 45.degree.. As
in the previous figure, one of the balls 31 is shaded to aid in
understanding the relative relationships between the various parts
during assembly. The inner joint part (not illustrated) is
articulated once again by the same angle .beta.2 in the same
direction relative to the cage 30. As can be seen from the detail
X, the second outer ball tracks 12, at the aperture 17 of the outer
joint part, comprise outwardly widened portions 13 which permit the
balls 32 of the second group of balls to be inserted at a
relatively small articulation angle .beta.2 of the ball cage 30
relative to the outer joint part 10. In cross section, the widened
portions 13 are adapted to the ball shape. The balls 32 which are
each positioned centrally relative to their cage windows 28 only
require windows of window length L2 which corresponds to the window
length required for articulation purposes in the operating range of
the joint. The length of the windows 27 for the balls 31 of the
first group of balls has again been given as L1, with the assembly
play on both sides corresponding to a1+a2=2a according to FIG. 2.
The distance a2 can become zero, in which case a1=2a.
[0037] The different illustrations of FIG. 4 will be described
jointly below. FIG. 4 substantially shows the same illustrations as
FIG. 3, but with reference to a joint of the conventional type. The
second outer ball tracks 12' do not comprise any outwardly widened
portions at the aperture 17', so that the cage 30' has to be
articulated at a greater angle .beta.1 as compared to the
previously shown angle .beta.2 around the second transverse axis 15
rotated by 45.degree. relative to the first transverse axis 14.
Equally, the inner joint part (not shown) has to be articulated
again by an identical angle .beta.1 relative to the cage in the
same direction to allow the insertion of the last one of the balls
32 of the second group of balls into its cage window 28'. This
means that, with the length L2 of the second cage windows 28' for
the second balls 32 remaining unchanged, it is necessary to provide
the cage windows 27 for the balls 31 of the first group of balls
with a greater circumferential length L1'. As a result, the webs
between the ball windows 27', 28' become shorter in the
circumferential direction, with the ball cage as a whole becoming
weaker. Identical details have been given the same reference
numbers as in FIG. 2, but these are provided with an
apostrophe.
[0038] FIG. 5 shows another embodiment of the inventive joint in
the form of a disc joint. That is, an outer joint part 10, at the
end opposed to an aperture 17, comprises a second aperture 16
instead of a base 18. The section extends through a plane through
the second outer ball tracks 12 and the second inner ball tracks
22, with the second outer ball tracks 12 showing the outwardly
widened assembly portion 13. The inner joint part 20 is integrally
connected to a driveshaft or journal 24. At the end of the aperture
17, the second inner ball tracks 22 of the inner joint part 20
comprise track run-outs 23 which permit considerable
over-articulation of the joint. Otherwise, identical details have
been the same reference numbers as in FIG. 1. To that extent,
reference is made to the description of FIG. 1.
[0039] FIG. 6 shows the joint according to FIG. 5 during the
assembly of the last ball 32 of the second group of balls, with the
balls 31 of the first group of balls already having been mounted.
The last ball 32 of the second group of balls can be inserted at a
relatively reduced angle of articulation because of the outwardly
widened assembly portion 13.
[0040] While the invention has been described in connection with
several embodiments, it should be understood that the invention is
not limited to those embodiments. Thus, the invention covers all
alternatives, modifications, and equivalents as may be included in
the spirit and scope of the appended claims.
* * * * *