Tool for repair of Rzeppa type constant velocity universal joint

A pliers type tool useful for removing and replacing bearings of a Rzeppa or constant velocity type universal joint includes a pair of separable jaws connected with translatable links of a hand tool. The jaws are inserted into the hub of the joint, spread and then the entire hub assembly is pivoted in order to expose the bearings sequentially for removal thereof or replacement thereof in the joint.

BACKGROUND OF THE INVENTION 
This invention relates to a tool which may be used to remove and replace 
the bearings of a Rzeppa or constant velocity type universal joint. 
Front wheel drive automobiles generally include a drive shaft from the 
engine connected through a universal joint to a spindle that drives the 
wheel. A popular type of universal joint utilized with such front wheel 
drive vehicles is known as a Rzeppa or constant velocity universal joint. 
Typically a Rzeppa universal joint includes a cup with a projecting 
spindle. The spindle is attached to a wheel. A series of ball bearings are 
retained within the cup arranged in a series of radial pockets in the cup. 
A single ball bearing is retained in each radial pocket by means of a 
slotted ring and a hub. The hub typically includes a splined opening or 
passage for receipt of a splined output shaft from the engine. Usually the 
bearings are enveloped in a lubricant retained within the cup by a boot 
which fits over the cup and the splined output shaft from the engine. 
From time to time it may be necessary to repack the lubricant or grease in 
the cup. In order to effectively do this, the universal joint is generally 
removed from the vehicle. The hub, ring and bearings are then removed from 
the cup. All the component parts are cleaned and the joint is then 
repacked with grease or other lubricant and reassembled. To effect this 
procedure, various tools are utilized. Typically the hub, ring and 
bearings are removed through the use of a hammer and brass chisel. The 
brass chisel, being relatively soft as compared to the steel parts forming 
the joint, will hopefully not damage the component steel parts of the 
joint when the chisel is used to separate the parts. The hammer and chisel 
are used to move the ring, hub and bearings relative to one another and 
relative to the cup. This particular procedure is somewhat time consuming 
and also requires acquisition of a skill with respect to disassembly and 
reassembly of a joint. 
Thus, there has remained a need to provide a tool which can be utilized for 
the quick and efficient disassembly or assembly of a Rzeppa type universal 
joint. 
SUMMARY OF THE INVENTION 
Briefly, the invention comprises a tool especially useful for removal and 
replacement of bearings in a Rzeppa type universal joint. The tool 
includes a pair of jaws which are designed to fit within a splined opening 
in the hub of a Rzeppa joint. The jaws are attached to links which overlie 
one another and are slidable with respect to one another so that by 
translation of the links relative to each other, the jaws may be spread to 
grip the sides of the splined opening in the hub. Handles attached to the 
links effect translation of the links and spreading of the jaws. After the 
jaws are positioned to grip the hub, the tool may be pivoted to 
simultaneously pivot the hub, ring and bearings of the joint within the 
cup of the joint. By pivoting the tool in various directions relative to 
the rotation axis of the cup, the hub pivots with respect to the ring and 
bearings in a manner which permits the bearings to be removed individually 
from the cup. Consequently all of the bearings may be removed ultimately 
permitting removal of the hub as well as the ring from the cup. The 
component parts of the joint may then be cleaned and repacked with grease. 
The tool may then be utilized to reverse the process and replace the hub, 
ring and bearings within the cup. 
Thus, it is an object of the invention to provide an improved tool for 
assembly and disassembly of a Rzeppa type universal joint. 
It is a further object of the present invention to provide an improved tool 
for repair of a Rzeppa type universal joint, and, in particular, a tool 
which eliminates the need for impacting on the joint with a chisel or the 
like. 
Still another object of the present invention is to provide an improved 
tool for repair of a Rzeppa type universal joint which is sturdy, 
economical, easy to utilize and capable of manual operation in a precision 
manner to effect the desired repair or replacement. 
These and other objects, advantages and features of the invention will be 
set forth in the detailed description which follows.

DESCRIPTION OF THE PREFERRED EMBODIMENT 
The improved tool of the invention is depicted in detail in FIGS. 5-8. The 
manner of use of the tool and its general overall configuration is 
depicted in FIGS. 1-4. 
Referring first to FIGS. 1-4, the tool of the invention is designed for use 
with a Rzeppa type universal joint. Typically such a joint, which is 
generally used in the drive train of front wheel drive vehicles, includes 
a spindle 10 defining an axis 12. The spindle 10 projects from a cup 14. 
The internal configuration of the cup includes a series of curved radial 
slots such as slot 16 and slot 18 in FIG. 3. A ball bearing 20 is mounted 
in slot 16. A separate ball bearing 22 is mounted in slot 18. A circular 
ring 24 has a window or channel 26 for ball bearing 20 and a window or 
channel 28 for ball bearing 22 positioned in opposed relation to the slots 
16 and 18 respectively. 
A hub 30 includes a series of opposed slots, such as slot 32 opposed to 
slot 16 and slot 34 opposed to slot 18. In this manner the slots 16 and 32 
define a channel in which a ball bearing 20 may run. Likewise, the slots 
18 and 34 define a channel in which the ball bearing 22 may run. In each 
circumstance the ring 24 and more particularly the window 26, 28 maintains 
the appropriate bearing in the appropriate slot. 
The hub 30 also includes a central splined passage 36. The passage 36 is 
adapted to receive a splined shaft 38 associated with the drive shaft or 
output from the vehicle engine. A rubber boot (not shown) fits over the 
splined shaft 38 and the cup 14 in order to maintain a seal of the 
materials within the cup 14. That is, the bearings 20 are maintained in a 
lubricated condition by a quantity of appropriate lubricant such as grease 
within the cup 14. A boot which fits over the shaft 38 and the cup 14 
maintains the lubricant within the confines of the cup 14. 
Heretofore when it was necessary to remove old lubricant and replace the 
lubricant or replace a component part of such a universal joint, the 
procedure involved removal of shaft 38 followed by tipping of the hub 30 
relative to the ring 24 and bearings, e.g. bearing 20, by means of a 
hammer and brass chisel. Only by impacting the component parts with a 
chisel relative to one another could the bearings be removed individually 
from their associated slot. Only after the bearings are removed is it 
possible to remove the hub 30 and ring 24. 
As shown in the drawing, the present invention comprises a tool which can 
be easily inserted into the passage 36 and then used to disassemble or 
reassemble the joint. Specifically the tool includes a first jaw 40 and an 
opposed second jaw 42. The jaws 40 and 42 are substantially identical in 
shape and arranged in opposed relation. The jaw 40 includes an outwardly 
displaced end portion 44 as does the jaw 42 which has an end portion 46. 
The end portions 44 and 46 flair outwardly from one another so that when 
the jaws 40, 42 are positioned within the passage 36, they will effect a 
gripping action on the sides of the opening or passage 36 as depicted in 
FIG. 3. Each jaw 40 and 42 has a longitudinal dimension z in FIGS. 6 and 8 
substantially equal to or greater than the length of the passage 36 in the 
hub 30. The flaired ends 44 and 46 thus extend beyond the passage 36 in 
the preferred embodiment. 
The first jaw 40 is integrally connected with a link or arm 48 that is 
generally transverse to the jaw 40. Thus, as depicted in FIG. 6, the jaw 
40 and link 48 define an "L" shaped configuration. Overlying the link 48 
is a second link 50 which is integrally connected with the second jaw 42. 
Again the configuration of the link 50 and jaw 42 is an "L" shape. 
The links 48 and 50 are in the form of planar members, slidable relative to 
each other. That is, the link 50 includes a longitudinal slot 52 through 
which a headed pin 54 is positioned. The pin 54 is attached to the first 
link 48 and projects through the slot 52 to limit the translation or 
slidable movement of the first link 48 relative to the second link 50. 
Also extending through a second slot 56 in the first link 48 and a third 
slot 58 in the second link 50 is a bolt 60 having a head 62. The bolt 60 
is threaded into a small semicircular plate 64 positioned against the 
bottom side of link 48. The semicircular plate 64 includes a notch 66 
having a lateral dimension sufficient to receive the jaw 40 or the jaw 42. 
The bolt 60 slides freely in the slots 56 and 58 and permits the plate 64 
to slide freely with respect to both of the links 48 and 50. The bolt 60 
has the function of maintaining the links 48 and 50 together in an 
overlying relationship so that sliding movement limited by the slot 52 and 
rivet or pin 54 will be maintained in a specific direction. Thus, the bolt 
60 and the rivet 54 define or guide the relative sliding movement of the 
links 48 and 50 with respect to one another. 
The bolt 60, however, is freely slidable within the slots 56 and 58 so that 
the plate 64 may move relative to both of the jaws 40 and 42. The plate 64 
fits on top of the hub 30 as depicted in FIGS. 3 and 4 and against the 
inside surface of the ring 24 so as to assist in positioning of the tool 
within the joint which is being assembled or disassembled. 
Extending transversely from the links 48 and 50 respectively are handles 68 
and 70 respectively. Handles 68, 70 are generally coplanar with the 
respective links 48, 50. Grips 72 and 74 are provided on the handles 68, 
70 for manual gripping of the handles 68 and 70. The handles 68 and 70 
define lateral axes 76 and 78 which are spaced from one another by a 
distance x which is variable depending upon the position of the handles 
68, 70. As the distance x is decreased, the spacing of the jaws 40 and 42 
is increased due to the sliding movement of the links 48 and 50 with 
respect to one another. 
In operation, after the jaws 40 and 42 are inserted in the passage 36, the 
handles 68 and 70 are gripped and squeezed thereby expanding the jaws 40 
and 42 against the opposite sides of the passage 36. Thus, the jaws 40 and 
42 are inserted in the passage 36 in the manner depicted by FIG. 3. The 
plate 64 is nestled against the hub 30 and the ring 24 to properly align 
the tool. The handles 68 and 70 are gripped and squeezed together so that 
the jaws 40 and 42 may be expanded. The hub 30 and ring assembly 24 is 
then rotated in the manner depicted in FIG. 2 by movement of the tool 
about axis 12 so that a bearing such as bearing 20 will slide in its 
appropriate slot 16 and simultaneously the hub 30 will rotate in a 
relatively greater arc guided by the tool. In this manner the bearing 20 
is exposed and can be removed from the cup 14. Subsequently, the tool is 
reoriented so that the bearing of another slot may be removed from the cup 
14. In sequence all of the bearings are removed from the cup 14 by virtue 
of the angular rotation of the hub 30 and ring 24 in response to actuation 
of the tool about axis 12. 
Once the bearings have been removed, then the hub 30 and ring 24 may be 
lifted from the cup 14. The cup 14, bearings 20, 22, hub 30 and ring 24 
may all then be cleaned and repacked with an appropriate lubricant. In 
order to reassemble the joint, the reverse procedure is followed. That is, 
the ring 24 and hub 30 are first inserted within the cup 14 and held by 
the tool positioned in the passage 36. Subsequently single bearings are 
positioned within windows or slots 26, 28 of the ring 24 once the ring 24 
is positioned as shown in FIG. 2 for receipt of a bearing. This procedure 
is followed in a sequence for each of the bearings and the entire joint is 
then reassembled. 
With the tool of the present invention, it is therefore possible to provide 
an improved means for assembling or disassembling a Rzeppa type universal 
joint. The necessity for impacting on the joint with a brass chisel, for 
example, is avoided. This avoids the potential for scratching or otherwise 
damaging the component parts of the joint. Additionally, the accidental 
introduction of brass shavings or shards into the joint is avoided. Thus, 
while there has been set forth a preferred embodiment of the invention, it 
is to be understood that the invention is to be limited only by the 
following claims and their equivalents.