Wheel bearing assembly

A bearing assembly particularly for the wheel of a motor vehicle wherein a wheel hub and a part of a universal joint are arranged in torque-transmitting engagement, the assembly including an inner race member formed by at least one of the wheel hub and the part of the universal joint in torque-transmitting engagement therewith and an outer race member adapted to be connected with the wheel carrier of the motor vehicle. First and second inner bearing tracks are formed in the inner race member and first and second outer bearing tracks are formed in the outer race member. A first and a second plurality of rolling elements are disposed in operative load-bearing engagement between the first inner and outer bearing tracks and the second inner and outer bearing tracks, respectively, and the outer race member is formed in two separate parts, one part having the first outer bearing track therein and the other part having the second outer bearing track therein. The two parts of the outer race member are arranged to be aligned with each other, and a securing device is provided for securing the two parts of the outer race member in the aligned position.

The present invention relates generally to a wheel bearing assembly 
particularly for use in motor vehicles and more particularly to a bearing 
assembly consisting of a double row of bearing elements which is capable 
of radial and axial load-bearing operation. 
In a device of the type to which the present invention relates, the outer 
race of the assembly is provided with a flange for fixing the bearing 
assembly to a wheel carrier of a motor vehicle and the inner race may be 
formed from the outer member of a rotary constant velocity universal joint 
through which the wheel hub is driven. 
In such a bearing assembly, it has previously been proposed to provide the 
running grooves or tracks of the inner race member of the bearing assembly 
in a unitary member which includes a sleeve and a wheel hub receiving 
flange and to provide the running grooves or tracks of the outer race in a 
unitary member which includes a flange adapted for connection to the wheel 
carrier. The sleeve may also form the outer part of the rotary constant 
velocity universal joint if the bearing assembly is intended for the 
driven wheel of a motor vehicle. An arrangement of this type is disclosed 
in British Patent No. 1 416 989. 
The disadvantage of a structure of this type is that there results a 
relatively large diameter for the bearing. In order to effect assembly of 
the bearing, the single component design requires that certain diameter 
dimensions be maintained. First, it is necessary to position the two race 
members with their respective axes offset radially, e.g., one above the 
other, when the axes are horizontal in order to enable introduction of 
rolling elements such as spherical balls into operative position. Only a 
maximum of half of the circumference may be filled with the balls. 
Subsequently, the balls must be distributed circumferentially and held in 
their repsective distributed positions by means of a cage which is axially 
introduced into the assembly. The relatively small degree to which the 
bearing may be filled with balls, i.e., the restricted number of balls 
which may be utilized, considerably limits the load-transmitting capacity 
of the bearing relative to the attainable capacity created by the 
diameters of the races. 
Divided bearing structures are also known wherein the running tracks for 
the rolling members of the bearing are arranged in separate bearing rings, 
for example, as disclosed in British Patent No. 1 298 552. However, the 
arrangement of the running grooves or tracks in separate bearing rings 
eliminates an advantage in that the possibility of reducing the diameter 
due to a more favorable degree of filling is lost, since the diameter must 
be increased because of the required mimimum thickness of the separate 
bearing rings. 
Therefore, the present invention is directed toward provision of a bearing 
assembly whereby the degree by which the assembly may be filled with balls 
is increased and whereby the load-carrying capacity is also increased 
while simultaneously permitting a reduction in diameter. 
SUMMARY OF THE INVENTION 
The present invention may be described as a bearing assembly for a wheel 
driven through a universal joint particularly for a motor vehicle wherein 
wheel hub means of said wheel are arranged in driven engagement with a 
part of said universal joint comprising: inner race means formed by at 
least one of said wheel hub means and said part of said universal joint; 
outer race means adapted to be connected with wheel carrier means of said 
motor vehicle; first and second inner bearing tracks formed in said inner 
race means; first and second outer bearing tracks formed in said outer 
race means; a first plurality of rolling elements disposed in operative 
load-bearing engagement between said first inner and outer bearing tracks; 
a second plurality of rolling elements disposed in operative load-bearing 
engagement between said second inner and outer bearing tracks; said outer 
race means being formed in two separate parts, one of said parts having 
said first outer bearing track formed therein and the other of said parts 
having said second outer bearing track formed therein; aligning means for 
aligning said two parts of said outer race means in operative position 
relative to each other; and securing means for securing in aligned 
position said two parts of said outer race means. 
The advantage of a structure in accordance with the invention is that there 
no longer exists a need for separate bearing rings, a measure which 
results in a decrease in diameter and an increase in the degree to which 
the assembly may be filled with rolling members thereby in turn increasing 
the load-bearing capacity of the assembly. Furthermore, dividing of the 
outer race means into two parts does not adversely affect the strength of 
the assembly. Preferably, both parts of the outer race means should be 
designed as a flange member whereby the outer race means may be affixed to 
the wheel carrier means and fixing holes may be provided in the flange 
parts with bushes provided in these holes having ends which are deformed 
in such a manner that the flange parts are firmly axially connected to 
each other. In this manner, the bushes act as the securing means for 
securing together the two parts of the outer race means. 
An alternative embodiment of the invention is constructed so that the two 
parts of the outer race means are designed as flanges and so that they are 
held axially and radially by a clamping ring. Thus, the securing means are 
embodied in the clamping ring and the function of centering of the flange 
parts is also undertaken by the clamping ring which also acts as the 
aligning means. 
In order to facilitate production and assembly of the flange parts, the 
bearing tracks are provided on one axial side thereof with an 
undercut-free runout which provides a lateral entry passage facilitating 
assembly of the rolling members. 
The various features of novelty which characterize the invention are 
pointed out with particularity in the claims annexed to and forming a part 
of this disclosure. For a better understanding of the invention, its 
operating advantages and specific objects attained by its use, reference 
should be had to the accompanying drawings and descriptive matter in which 
there are illustrated and described preferred embodiments of the invention 
.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
Referring now to the drawings, and particularly to FIG. 1, there is shown a 
bearing assembly for the wheel of a motor vehicle wherein the inner race 
means of the bearing assembly are formed as comprising a wheel hub 2 
having a flange portion 1 for engagement with a wheel to be supported, 
with the other end portion of the inner race means being formed from an 
outer member 3 of a rotary constant velocity universal joint. For 
simplification, the remaining parts of the rotary constant velocity 
universal joint are not shown in the drawings. 
The inner race means comprised of the wheel hub 2 and the outer member 3 is 
formed on the outer surface thereof with running grooves or bearing tracks 
4 and 5 which form first and second inner bearing tracks of the bearing 
assembly. 
The bearing assembly is also composed of outer race means which are 
comprised of a pair of outer race members 8a and 8b each formed as 
individual flange elements adapted for attachment to the wheel carrier 
means of a motor vehicle. The individual outer race members 8a and 8b are 
each formed, respectively, with first and second outer bearing tracks 7 
and 6 of the bearing assembly, the outer race member 8a having formed 
therein the track 7 and the outer race member 8b having formed therein the 
track 6. Both of the outer race members 8a and 8b are centered relative to 
each other by a centering projection 10 and they are provided with a 
receiving bore 9. The interior of the bearing assembly is sealed by a seal 
member 11 arranged between the two outer race members 8a, 8b and the inner 
race member. 
The bearing assembly is also essentially comprised of a plurality of 
rolling elements 19 formed as two rows of spherical balls, with one row of 
spherical balls 19 being in operative load-bearing engagement between the 
first inner and outer bearing tracks 5, 7 and with the second row of balls 
19 being in operative load-bearing engagement between the second inner and 
outer bearing tracks 4, 6. 
The balls are held in operative load-bearing engagement in their respective 
positions by a cage 21 and the outer bearing tracks 6 and 7 of the two 
outer race members 8a, 8b in which the receiving bores 9 are formed are 
open toward one end thereof so that there is no undercut, i.e., they are 
formed with an area having an undercut-free running groove runout 20 which 
is at least parallel relative to the axis of the assembly. Thus, the 
tracks 6 and 7 are formed with one lateral boundary or wall portion which 
is open laterally at opposed inner lateral boundaries which in combination 
with the grooves 4 and 5 define the entry passage 20 which permits lateral 
assembly between each pair of opposed grooves 4, 6 and 5, 7 of the balls 
19 by relative passage through the passageway 20. In practice, the balls 
19 may be loaded between the grooves 4 and 6 and further balls may then be 
assembled in groove 7 and the part of the outer race means incorporating 
the part 8a may then be moved axially over the end 3 of the inner race 
member. The number of balls is not limited to those balls which fill only 
half of the circumferential length of the ball receiving channel between 
opposed grooves, but may exceed such number. 
In FIG. 2 there is shown in greater detail a portion Z of the outer race 
means identified in FIG. 1. In the detail of FIG. 2, there is provided 
bushes 13 which are inserted into the aligned holes of the members 8a, 8b 
forming the flange hole 12. In FIG. 2, the bush 13 operates for connecting 
together the two parts 8a and 8b of the outer race means. The bushes 13 
are inserted into the holes 12 of the members 8a and 8b and the ends 14, 
15 of the bushes 13 are deformed ih such a manner that they are secured 
with respect to the end faces of the members 8a, 8b. Thus, the deformed 
ends 14, 15 of the bushes 13 operate to secure the two parts of the outer 
race means against axial separation relative to each other and they also 
serve to apply an axial preload to the race means and to the rolling 
elements 19. 
An alternative embodiment of the invention is shown in FIG. 3 wherein the 
two members 8a and 8b of the outer race means formed as flange parts may 
be affixed together by a clamping ring 16 having two sides 17 and 18 which 
grip the flange parts or race members 8a and 8b thereby holding them 
together in axially fixed position relative to each other and applying a 
preload to the bearing components previously mentioned. The clamping ring 
16 may also serve for centering of the two flange elements or race members 
8a, 8b in which case there is eliminated the need for the centering 
projection 10 and the receiving bore 9. 
In the case of the flange part 8a, for example, it is also possible to 
eliminate the part containing the fixing bores 12 so that it consists only 
of a component which is provided with the outer bearing track 7 and which 
is centered and additionally fixed by means of the centering projection 10 
and the receiving bore 9 relative to the flange and by means of the other 
outer bearing track 6. Of course, some holes or other formations would be 
required on one or both of the race elements 8a, 8b in order to enable the 
outer race means to be secured to the wheel carrier of the vehicle. 
The inner grooves are formed of a cross-sectional configuration so as to 
provide wall portions for bearing axial loads in both axial directions. 
Furthermore, the balls 19 forming the two bearing rows are held 
circumferentially in the bearing tracks 4, 6 and 5, 7 and they may be held 
respectively by one single cage 21 or even by two cages arranged in a row. 
Thus, from the foregoing it will be seen that the invention provides a 
bearing assembly for the wheel hub of a motor vehicle arranged at the 
respective wheel carrier and consisting of a double row axial-radial 
bearing assembly. The bearing assembly may be designed either in such a 
way that it serves only to support nondriven wheels or it may include the 
outer part of a rotary constant velocity universal joint pertaining to a 
drive shaft of the wheel for transmitting torque from the engine to the 
wheel. The invention enables the structure to be formed with a compact 
design consisting of as few parts as possible, and this objective is 
achieved in that the outer ring of the bearing ring is divided into two 
parts and is formed as two flange members which are centered and which are 
clamped relative to each other. 
While specific embodiments of the invention have been shown and described 
in detail to illustrate the application of the inventive principles, it 
will be understood that the invention may be embodied otherwise without 
departing from such principles.