Note: Descriptions are shown in the official language in which they were submitted.
CA 02464293 2004-04-13
__~_..
Whee! Bearing Assemblies lneorporating Sensing Arrangements
aaoaa2az
The present invention relates to vehicle wheel bearing assemblies and more
particularly to such assemblies equipped with sensing arrangements for sensing
rotary
speed or positian_
In this field there have been many prior art constructions which can be taken
to
form the background for the invention. In general, rotary bearings employing
sensing
arrangements for sensing rotary speed or position can employ a pre-fabricated
annular
component made of polymeric material containing ferrous material which is
treated to
form alternate north and south magnetic poles, see for example, US Patent
SD8981 ~.
Such a component referred to as an encoder can be mounfed in the assembly'to
cause
the magnetic poles to pass alongside a sensor, such as s Ball effect sensor,
which
generates a pulsed electrical signal,
An object of the present invention is to provide improved assemblies and
sensing
1 S arrangements of the aforementioned kind-
Accordingly the present invention provides a wheel bearing assembly composed
of
Inner and outer bearing rings, one of which is intended to rotate and the
other of which is
intended to remain Stationary, two sets of rolling elements between the rings
and in
angular contact with tracks defined by the rings, each set of rolling elements
being
spaced in the direction of the axis of rotation with each set of rolling
elements retained by
one of two cages and a sensing arrangement composed of at least two annular
encoders with alternate north and south magnetic poles and at feast two
sensors
operably associated with the encoders and each serving to provide electrical
signals
generated by the passage of the poles of the associated encoder;
wherein one of the encoders is mounted on the rotatable one of the bearing
rings
and,
the other of the encoders is mounted on e~ne of the cages and
CA 02464293 2004-04-13
A40402d1
each of said sensors and encoders is disposed axially, between the sets of
roiling
elements.
The encoder can be mounted on different components of the assembly such as on
one of the cages and on the rotatabte bearing ring. This enables the signals
generated
by the sensors to be compared, for example. The encoder. can be orientated
with their
magnetic poles parallel to the rotakional axis thus in an axiial orientation
or radial to this
axis thus in a radial orientation or in both axial and radial orientations.
The sensors and
encoders may be built into the bearing in a protected position between the
sets, of rolling
elements- To locate the sensors use can be made of a housing or a mounting'as
described hereinafter.
In other embodiments the sensors and encoders lie outboard of the bearing and
the wheel assembljr for ease of installation or removal. ;
A second aspect of the present invention provides a wheel bearing assembly
composed of inner and outer bearing rings, one of which is intended to rotate
and the
1 S other of which is intended to remain stationary, sets of rolling elements
between the
rings and in angular contact with tracks defined by the rings, the sets of
rolling elements
being spaced in the direckion of the axis of rotation with each set of rolling
elements
retained by a cage and a sensing arrangement composed of at least fwo annular
encoders with alternate north and south magnetic poles and at least two
sensors
operably associated with the encoders and each serving to provide electrical
signals
generated by the passage of the poles of the associated encoder; .
wherein one of the encoders is mounted on the rotatable one of the bearing
rings
and, ' '
the other of the encoders i~ mounted an one of the cages and wherein the inner
ZS bearing ring is secured onto a wheel hub, a cover is located on the other
bearing ring to
enclose the sensors and is carcied by an axial portion of the cover.
CA 02464293 2004-04-13
._ 3 __
A40402d1
The invention may be understood more readily, and various other aspects and
features of the invention may become apparent, from consideration of the
following
description.
Wheel bearing assemblies embodying the invention will now be dESCribed, by way
of examples only, with reference to the accompanying drawings, wherein:
Figure 1 is a schematic sectional side view of a first embt~diment of a wheel
bearing assembly;
Figure 2 is an enlarged view of part of the assembly shown in Figure 1;
Figure 3 is a schematic sectional side view of a second embodiment of a-wheel
bearing assembly;
Figure 4 is a schematic sectional side view of a third embodiment of a wheel
bearing assembly,
Figure 5 is a schematic seckional side view of a fourth embodiment of a wheel
bearing assembly,
1 S Figure 6 is a schematic sectional side view of a fifth embodiment of a
wheel
bearing assembly,
Figure 7 is a schematic sectional side view of a sixth embodiment of a wheel
bearing assembly,
Figure 8 is a schematic sectional side view of a seventh embodiment of a wheel
2t) bearing assembly
Figure 9 is a schematic sectional side view of an eighth embodiment of a wheel
bearing assembly. ::
The construction of the various wheel bearing assemblies 9 illustrated
throughout
the accompanying drawings is well known parse and like reference, numerals are
used
25 to designate the same components.
CA 02464293 2004-04-13
A40402d1
--4-
Referring initially to Figure 1, there is an inner bearing ring 10, an outer
bearing
ring 11 and two sets or rows of rolling elements in the form of balls 12
therebeiween.
The balls 12 make angular contact with running tracks 13, 14 in the rings 10,
11. In this
assembly, the right-hand or innermost track 14 of the ring 10 is actually
formed by a
S separate support 15 located in a recess 8 in the inner ring 10. A wheel hub
is fixed to or
integral with the inner ring 10 and receives a nut 16 which locates on the
support 15. A
detachable pressing fits into an outer projecting region 5 of the outer ring
11 and acts as
a cover fi for the nut 16_ At the opposite left-hand or outermost end regions
of the rings
10, 11 there is. a seat 17. Each set of balls 12 is fitted into a cage 18, 1 J
made of
plastics material. As is known, the cages 18, 19 maintain separation between
the bans
12 and guide the balls 12 making up each sei for progression around the tracks
1~, 14.
During use, the inner ring 10 rotates with the wheel hub whilst the outer ring
11. remains
stationary. The balls 12 progressively roll in relation to the tracks l3, 14.
In accordance with the invention, the assembly 9 is equipped with a sensing
arrangement designed to provide an indication of rotary speed or position. As
shown in
Figures 1 and 2, the cage 19 has an axial projection 20 which extends
outwardly towards
the other ball set. A first pre-formed annular encoder 21 with alternate
axially-orientated
north and south magnetic poles is fitted onto an axial surface 22 of the
projection 20 to
confront the inner surface of the outer ring 11. A second pre-formed annular
encoder 23
2(? with alternate north and south axially-orientated magnetic poles is fitted
onto the inner
surface of the inner bearing ring i 0. The encoders 29 , 23 are axially and'
radially offset
in relation to one another.
A radial bare 24 in the otter ring 11 receives a housing 25. As shown in
Figure 2,
the inner end of the housing 25 has a stepped profile with end walls 26, 27
offset in the
radial direction. The end walls 25, 27 mount sensors 28, 2E~ which detect the
passage of
the magnetic poles of the encoders 21, 23 and provide pulsed electrical
signals with a
repetition frequency depending on the rnavement of the poles of the encoders
21, 23.
CA 02464293 2004-04-13
__ g __
A40402d1
The signals are tarried on leads 30, 31 connected With the sensors 28, ~9_ The
signals
from the sensor 28 represent the rotary speed of the cage 19 while the signals
from the
sensor 29 represeht the rotary speed of the inner ring 10. The signals can be
used in a
variety of ways quite separately and independently or combined or compared
with one
another.
Figure 3 shows a mod~ed form of the sensing arrarlgement shown in Figures 1
and 2. In this arrangement, the encoder 23 is mounted on a suppork ring 32
fitted to the
inner surface of the inner bearing ring 10 and the magnetic poles of the
encoders 22, 23
lie in a common axial plane. The associated sensors 28, 29 are likewise
orientated in a
common axial plane Corresponding to the inner surface of the outer ring 11 _
The
sensors 28, 29 ace mounted at the inner end of a bore 2~4. in the ring 11. The
lads 30,
31 are used to support and position the sensors 28, 29 and these leads 30,
31emerge
from the bore 24_
In the embodiments described and illustrated so far the encoders and sensors
21,
1S 23, 28, 29 are all inboard between the sets of balls 12.
In other constructions the encoders and sensors can be outside the bearing
interlor_ Thus, Figure 4 shows another sensing arrangement with two encoders
21, 23
and two sensors 28, 29. The first encoder 21 is again located on an axial
projection 20
of the cage 19 but in this embodiment the projection 20 extends outwardly
rather than
2U inwardly. The second encoder 23 is mounted on an axial region of a further
LTshaped
ring 33 disposed outside the bearing. ~l radial region of this ring 33 is
clamped by the
nut 16 against the support 16. As with the arrangement shown in Figure 3, t#~e
magnetit
poles of the encoders 21, 23 lie in a common axial plane as do the opposed
associated
sensors 28, 29 which are now supported an an axial portion 34 ~f the cover 6.
25 In the assemblies and arrangements depicted in Figures 1 to 4 the encoders
21,
23 and the sensors 28, 29 are located predominantly in the axial disposition.
Figures 5
and 6 show somewhat different arrangements where the encoders 2i , 23 and the
CA 02464293 2004-04-13
__ 6 __
A40~02d1
sensors 28, 29 take a radial disposition. In the arrangement shown in Figure S
the
encoder 21 is mounted on an outermost radial surtace 35 of the outer cage 19
so the
magnetic poles take a radial orientation. The encoder 23 is here mounted on a
plane
washer 36 clamped between the nut 16 and the support 16. As can be seen, the
encoders 21, 23 are both axially and radially offset. The associated sensors
28, 29 are
likewise axially and radiatly offset and suspended, for example, by a
deformable sleeving
surrounding the leads 30, 31 and bent into an f_-shape. The sieeving can be
secured to
the axial portion 34 of the cover fi in any suitable fashion.
Figure 6 shows another arrangement with the encoders 21, 23 and the sensors
2$,
29 all in a radial orientation. In this arrangement, the encoder 21 is
supported nn the
innermost radial end face 35 of the cage 18. The encoder 23 confronts the
encoder 21
and is radialiy aligned but axially ofFset with respect to the encoder 21. A
support ring 39
fits into a recess 43 in the inner surface of the inner bearing ring 1 Q and
the support ring
39 serves to mount the encoder 23. The associated sensors 2$, 29 are again
suspended by their leads 30, 31 iri the sensor vicinity of the encoders 21,
23. The leads
30, 31 pass through the bore 24 in the bearing ring 11.
Figure 7 shows an arrangement where the encoders 21, 23 and the sensors 28, 29
are orientated both radiaiiy and axially_ Thus, the encoder 21 is again
mounted on the
radial surface 35 of the cage 18 as is in the embodiment shown in Figure 5.
However
the washer 36 is now !_-shaped wi#h an axial region 37 supporting the encoder
23 in an
axial orientation generally normal to the orientation of the encoder 21. A
tubular housing
again secured to the axial portion 34 of the cover f accommodates the sensors
28,
29, The.housing 25 has a radially orientated' inner end wall 3$ supporting the
sensor 28
in the sensing vicinity of the encoder 21 and an axial wall 3'9 supporting the
sensor 29 in
25 the sensing vicinity of the encoder 23.
Figure 8 depicts a similar arrangement to Figure $ E~ui: here the shape and
mass of
the support ring 37 for the encoder 21 is modified. The ring 39 is now L-
shaped and has
CA 02464293 2004-04-13
__ 7 __
A40402d1
an axial ftangE portion 41 fitted directly to the inner surface of the inner
ring 1 O which is
no longer provided with a recess.
Figure 9 is again similar to the arrangement shown in Figure 8 but here the
encoder 21 is fixed to the cage 18 with screws. fn this arrangement the
mounting of the
sensors 28, 29 is achieved with the aid of a mounting block 42. The mounting
block 42
has a flange 48 affixed with screws 44 to the outer bearing ring 11. A bore 45
in the
block 42 is co-axial with the bore 24 in the ring 11. An elongate carrier 46
extends
through the bores 45, 24 and mounts the sensors 28, 291'ace-to-face in
opposite
directions. A further sctew 47 is received in a wall of the bloclr 42 to
penetrate, the bore
4S and the screw can be used to adjustably locate with the carrier 4C.
In the assertlblies and arrangements depicted in the dnav~imgs and described
heteinbefore there is two encoders and two sensors. In Figure 10 a modified
arrangement is depicted which uses three encoders and three sensors. Thus in
Figure
10 a first encoder 21 is mounted on an outer end surface 3S of the cage 18 and
fakes a
radial orientation_ A second encoder 23 is mounted on the inwardly directed
end face 48
of the cage 19 in confronting relationship to the encoder 21 and likewise take
a radial
orientation. The encoders 21, 23 are in radial alignment but spaced apart
axially. A third
encoder 49 is mounted on a support ring 50 fitted in a shallow recess S1 in
the inner
surface of the inner ring 10. The third encoder 49 takes an axial orientation.
The
sensors associated with the encoders are again supported by s common housing
2S
located in their bore 24 in the outer bearing ring 11 _ In this; case the
radially orientated
sensors 28, 29 associated with the encoders 21, 23 are (orated in an annular
ridge
portion 52 at the end of tire housing 25 while a further sensor 53 associated
vriith the
third encoder 49 and located in 3n axial orientation is located centrally of
the inner end of
the housing 25 within the end ridge portion 52 and radially offset therefrom_
