CA1067128A - Bearing cages - Google Patents

Abstract

CANADA

"IMPROVEMENTS IN OR REBATING TO BEARING CAGES"

Abstract of the disclosure A plastics cage for a ball bearing in which wipers are formed integrally with projections of the ball pockets.

Description

- 1067~Z8 This invention relates to a plastics cage for a ball bearing having means to discourage foreign ~atter from entering the bearing raceways when the bearing in whlch the cage ls assembled is in use.
The invention is concerned with cages of the kind having an annular wall ant spacet part-spherical pockets, a part of each pocket being formet by a recess in the annular wall~ the remainder of the pocket being formed ...... ........... ...... ........................................................... ::
by two pro~ections which extent away from the annular wall with the nouth of the pocket between them. Such . , .
- a plastics cage is hereinafter referred to as "a cage of the kind described".
The invention particularly relates to certain .. . .
constructions of cages in which wipers are formed lntegrally with pro~ections of the ball pockets to teflect foreign matter which woult otherwise enter the space contained between at~acent ball pockets ant ~
thus prevent the foreign matter from being eventually ~-., . :
~ depositet on the raceways of the bearing rings.
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,' 20 The type of application where deflector wipers would be of significant value is for example in conveyor plant ~`;
~- where the bearings in the conveyor belt support rollers rotate at relatively moderate-slow speeds and where the , ~ .
environment in which they operate is very arduous in -~ 25 terms of tust and dirt. It has been found that the ,. ,, -:
foreign maeter has a tendency to build up on the stationary bearing ring land and where the stationary ring is the inner ring, this build up also occurs on the ad~acent shaft. When the dust/dirt builds up it '' .
beco~es unstable ant cascades into the bearing raceways thereby leading to rapid seizure of the bearing.
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The object of the deflector wipers, therefore is to dis_ourage -the entry of foreign matter into the bearing raceways via the space between the ball pockets and to prevent the build up of material on the bearing lands by wiping with projections from the cage. To give the fullest pro-tection the wipers and projections are sited between or adjacent all the ball pockets.
Accordingly the invention provides a cage of the kind described having at least one wiper which extends from, and is formed integrally with a respective projection of a cage pocket.
The wiper may extend axially from the annular wall in the same direction as and further than the respective projection. The wiper might otherwise form an extension of the free end of the respective projection.
Constructions of cages embodying the invention will now be described by way of example, with reference to the accompanying drawings in which~
Pigure 1 is an axial view of part of a ball bearing showing a barrier integral with one projection of a ball pocket;
Pigure la is a section on the line M in Figure l;
Figure lb is a perspective view of part of the cage shown in Figures 1 and la, Figure 2 is another view similar to Figure 1 in which the wiper is an integral extension of one projection of a cage pocket;

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~ ~()6'71Z9 Figure 2a ~s a section on the line AA of Figure

2; and ~, Figure 2b is a perspective view of part of the cage shown in Figures 2 ant 2a;
` S Referring now to Figures 1, la and lb of the drawings~ there is shown part of a ball bearing comprising an inner race ring 2, an outer race rin8 3 ~ ;
and an annular series of balls 4 arranget to roll on the raceway of both bearing rings. The balls 4 are each located in a cage pocket 5 which is an integral part of a plastics cage 6. Each pocket is formed in part by a psrt-spherical recess in an annular wall 7 o the cage, the remainder of the pocket being formed by a pair of pro~ections 8 integral wlth the annular wall with the mouth of the pocket located between ~'' sait pair of pro~ections. A ball which comes into , ~ contact with the free eDds of the pair of pro~ections i will be snapped into the pocket through the mouth ` thereof when an axial force is applied to the cage.
This snap action is effected by the resilient bending *~ of the pro~ections 8 away from each other and the ; resilient flexing of the pocket 5 about an axis which .
is radial of the cage, through its base.
Each wiper is formed integrally with one pro~ection of a ball pocket. In Figure 1 the wiper 21 is integral with the pro~ection 8 and extends axially from the annular wall of the cage in the same ; direction as and further than pro~ection 8. The ; wiper 21 extends across the full radial width of the cage 20 whereby the radial faces 10,11 of the wiper in the assemblet cage are closely ad~acent the surfaces 12, 13 of the inner and outer race rings `',' ;,: `

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10671Z~

2, 3 respectively of the bearing (Figure la). As can be seen in Figure la the wiper pro~ects axially to terminate close to one axial end face of both races .
so as to provide a deflector against which foreign ` 5 matter can impinge ant thence tiscourage the entry `-into the bearing raceways. The radial faces 10,11 act as wipers to discourage foreign matter from collecting on the surfaces 12, 13 of the shoulders.
, The wipers 21 could also be substantially thinner than a~ shown and deflect in the opposite direction of rotation to that of the cage when oreign material impinges on the wipers or when the wlpers rub on the bearlng lands~
"' In the modlflcatlon shown ln Figure 2 the wipers 21 extent from the end of the respective pro~ections 8 , of the respective pocket~ but otherwise the assembly is simllar to that previously described. ~-,., '' ' .

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Claims

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. A plastics cage for a ball bearing, the cage having an annular wall and spaced part-spherical pockets, a part of each pocket being formed by a recess in the annular wall, the remainder of the pocket being formed by two projections which extend away from the annular wall with the mouth of the pocket between them, in which the cage has at least one wiper which extends from, and is formed integrally with a respective projection of a cage pocket.

2. A cage according to claim 1 in which the wiper extends axially from the annular wall in the same direction as and further than the respective projection.

3. A cage according to claim 1 in which the wiper forms an exten-sion of the free end of the respective projection.

4. A cage according to any of claims 1 to 3 in which the wiper is thinner than the respective projection.

5. A ball bearing including a cage according to

claim 1.