GB2049070A

GB2049070A - Bearings

Info

Publication number: GB2049070A
Application number: GB7916776A
Authority: GB
Original assignee: Jones & Co Ltd A & H
Current assignee: Jones & Co Ltd A & H
Priority date: 1979-05-14
Filing date: 1979-05-14
Publication date: 1980-12-17
Also published as: GB2049070B

Abstract

A ball bearing is provided with a cage 16 which, in addition to holding the balls in spaced relation, also includes integral sealing lips 20, 22 which sealingly engage the inner and outer races to prevent the ingress of foreign matter. There may be a single cage inserted from one side of the bearing and engaging all of the balls or two cages inserted from opposite sides and engaging respective sets of alternate balls. <IMAGE>

Description

SPECIFICATION Bearings This invention relates to bearings of the kind comprising an inner race, an outer race and a series of rolling elements (e.g. balls) located between the two and held in spaced relation by a cage.

The object of the invention is to provide a bearing of the kind referred to with improved sealing means for preventing ingress of foreign matter into the bearing. It is of course known to provide sealing arrangements for this purpose but as far as we are aware the seals have been assembled separately which increases costs and assembly time and sealing arrangements are therefore usually only adopted for precision bearings.

According to the present invention we provide a bearing of the kind referred to in which the cage is formed of a resiliently deformable material and includes an integral sealing lip along at least one of its inner and outer peripheral edges which sealingly engages with the inner or outer race respectively.

In one embodiment, the cage comprises an annulus from one side of which a series of integral tongues extend laterally to define ball-receiving openings and the other side of which is formed with said integral lip(s).

This type of cage is effective to seal only one side of the bearing and in many situations this is adequate because the bearing will for example be assembled in a recess or housing with said other side facing the base of the recess and hence effectively sealed thereby. However, it is within the scope of the invention to seal both sides of the bearing by providing a two-part cage, the two parts being assembled from opposite sides of the bearing and each having a sealing lip(s) for cooperation with the respective sides of the bearing races.

According to another aspect of the invention we provide a method of assembling a bearing of the kind referred to, in which the rolling elements are assembled to the bearing races and the cage is thereafter inserted from one side of the bearing into the gap between the races so as to engage with the rolling elements, the cage being of resiliently deformable material and having at least one sealing lip which, during said insertion step, makes sealing engagement with the inner or outer race of the bearing.

In a modification of this method where the cage is of two-part construction as aforementioned, the cage parts are inserted into the gap between the races from opposite sides of the bearing and the sealing lips thereof are brought into sealing engagement during the insertion step.

Thus, it will be seen that the present invention obviates the need for a separate sealing procedure because sealing is effected automatically during assembly of the cage or cage-parts to the bearing races.

Embodiments of the invention will now be described by way of example only with reference to the accompanying drawings, in which: Figure 1 is a diametral section through a bearing in accordance with the invention; Figure 2 is an axial view taken in the direction 2 in Figure 1; Figure 3 is a radial view of the cage of the bearing in Figure 1; Figure 4 is an axial view of the cage; Figure 5 is an enlarged fragmentary sectional view of the cage; Figure 6 is a fragmentary diametral section of a modified bearing provided with cages inserted from each side thereof; Figure 7 is a radial view of one of the cages of the bearing in Figure 6; and Figure 8 is an axial view of the cage shown in Figure 7.

Referring firstly to Figures 1 to 5, the bearing shown is one which requires sealing from one side only, for example in situations where the bearing is to be assembled in a recess or housing with the unsealed side facing the base of the recess or where the bearing is to be assembled alongside an identical bearing with the unsealed sides of the two bearings opposed. As shown, the bearing comprises inner and outer races 10, 12 formed with continuous ball receiving grooves for axial location of a piurality of balls 14 of which six are shown in the embodiment of Figures 1 to 5. The balls 14 are held in circumferentialiy spaced relationship by a cage 1 6 which is inserted from one side of the ball bearing, namely the righthand side as viewed in Figure 1.

The cage comprises a generally annular body portion provided, on one side thereof, with integral radially outwardly and inwardly projecting lips 20, 22 which taper towards their free ends and are truncated to form circular inside edges 24, 26. The inside faces 28 of the lips 20, 22 are of generally conical configuration whilst their outside faces 30 are substantially flat and co-planar.A number of integral tongues 32 project from the opposite side of the body 1 8 and form therebetween a number of ball receiving pockets 34 of part-circular configuration for snugly receiving the balls, the pockets 34 having open mouths 36 through which the balls enter during insertion of the cage between the races 1 0, 12. To facilitate entry of the balls into the pockets 34, the tongues 32 are recessed at their free ends to form flexible wall portions 38 in the vicinity of the mouths 36. The whole cage is conveniently manufactured from a resiliently deformable plastics material such as nylon so that the various portions thereof, including the lips 20, 22 are elastically deformable.

To assemble the bearing of Figures 1 to 5, the races and balls are first assembled together and the balls are spaced apart at approximately the correct spacing, the cage is then inserted (from the righthand side as seen in Figure 1) by pressing it into the gap between the races so that its tongues enter first and undergo deformation, particularly the wall portions 38, until the balls enter the pockets 34. When the cage has been inserted to this extent, the lips 20, 22 will make sealing engagement with the races. Thus, sealing is effected automatically upon insertion of the cage.

The arrangement is such that the sealing engagement between the lips 20, 22 and the races is substantially line contact so as to minimise frictional resistance between the cage and the races. To this end, the races 10, 12 are formed with rebates 40, 42 whose bases are of generally conical configuration but have apex angles which are smaller than those of the inside faces 28 of the lips 20, 22 so that only the inside edges 24, 26 of the lips 20, 22 make contact with the rebate bases.The axial spacing between the centres of curvature of the pockets 34 and the edges 24, 26 of the lips 20, 22 is such that, when the balls 14 are engaged in the pockets 34, the cage is located inwardly of the bearing to such an extent that the lips 20, 22 are deflected thereby increasing the sealing affect due to the tendency for the lips 20, 22 to return to their unstressed positions.

The embodiment of Figures 6 to 8 is generally the same, in principle, as that of Figures 1 to- 5 except that two cages are employed, the cages being identical and being inserted from opposite sides of the bearing. In this embodiment, each cage engages with only half of the balls of the bearing. In the embodiment of Figures 6 to 8, eight balls are employed with four being engaged by one cage at 900 intervals and the remaining four being engaged by the other cage also at 900 intervals. In Figures 6 to 8, the same reference numerals are used as in Figures 1 to 5 to identify like parts.

It will be noted that the tongues 32 of each cage define ball receiving pockets 34 and are grouped in pairs separated by gaps 50 so that the two cages can be interdigitated, i.e. with the tongues 32 of one cage located in the gaps 50 of the other cage.

The method of assembly of the bearing of Figures 6 to 8 is substantially the same as for the bearing of Figures 1 to 5 except that two cages have to be inserted, one from either side. In all other respects, the bearing of Figures 6 to 8 is substantially the same as that of Figures 1 to 5.

Claims

1. A bearing of the kind referred to in which the cage is formed of a resiliently deformable material and includes an integral sealing lip along at least one of its inner and outer peripheral edges which sealingly engages with the inner or outer race respectively.

2. A bearing as claimed in Claim 1 in which the cage is annular, said lip(s) being provided at one side of the annulus, and in which integral tongues of material project from the other side to form, between adjacent tongues, ball-receiving pockets of part-circular configuration whose mouths open at the side of the cage remote from the sealing lip(s).

3. A bearing as claimed in Claim 2 in which the free ends of the tongues are received to afford flexible wall portions in the vicinity of the mouths of said ball-receiving pockets to facilitate entry of the balls into said pockets.

4. A bearing as claimed in Claim 2 or 3 in which the or each sealing lip engages a surface on the inner/outer races and in which the balls engage snugly within said pockets in such a way that the cage is located in a position wherein the lip(s) is/are caused to undergo deflection by engagement with said race surface(s).

5. A bearing as claimed in any one of Claims 4 in which the or each lip tapers in a radial direction away from the body of the cage.

6. A bearing as claimed in Claim 5 in which the radial extremity of the or each is truncated and in which the arrangement is such that the inside edge of the lip makes substantially line contact with a surface of the respective race.

7. A bearing as claimed in Claim 5 or 6 in which the or each lip has an inside face of conical configuration and engages an outside face of the respective cage which is also of conical configuration, the apex angle of said lip face being greater than that of said cage face.

8. A bearing as claimed in any one of Claims 1-7 in which said cage engages alternate ones of said balls, the remaining balls being engaged by a second and identical cage inserted from the opposite side of the bearing, the two cages have interdigitated ball receiving pockets.

9. A method of assembling a bearing of the kind referred to, in which the rolling elements are assembled to the bearing races and the cage is thereafter inserted from one side of the bearing into the gap between the races so as to engage with the rolling elements, the cage being of resiliently deformable material and having at least one sealing lip which, during said insertion step, makes sealing engagement with the inner or outer race of the bearing.

10. A bearing substantially as hereinbefore described with reference to, and as shown in, Figures 1-5 or Figures 6-8 of the accompanying drawings.

10. A modification of the method claimed in Claim 9 in which there are two of said cages and in which each cage is inserted into the gap between the races from opposite sides of the bearing and the sealing lips thereof are brought into sealing engagement during the insertion step.

11. A method as claimed in Claim 9 in which the bearing is of the form claimed in any one of Claims 1-8.

12. A bearing substantially as hereinbefore described with reference to, and as shown in, Figures 1-5 or Figures 6-8 of the accompanying drawings.

13. A method of assembling a bearing substantially as hereinbefore described with reference to Figures 1-5 or Figures 6-8 of the accompanying drawings.

New claims or amendments to claims filed on 28 Aug 1979.

Superseded claims 1-13.

New or amended claims:

1. A bearing of the kind referred to in which the cage is formed of a resiliently deformable material and includes an integral sealing lip along at least one of its inner and outer peripheral edges which sealingly engages with the inner or outer race respectively, characterised in that the cage is so designed that it can be inserted from one side of the bearing between the races so as to engage with the balls and receive them within ballreceiving pockets thereof, the or each sealing lip engages a generally radially extending surface on the inner/outer races, the balls engage snugly within said pockets in such a way that the cage is located in a position wherein the lip(s) is/are caused to undergo deflection by engagement with said race surface(s), and the or each lip has a generally radially extending surface facing the respective generally radially extending surface of the inner/outer race, said facing surfaces being angularly inclined relative to one another such that they contact adjacent the peripheral edge(s) of the lip(s).

3. A bearing as claimed in Claim 2 in which the free ends of the tongues are recessed to afford flexible wall portions in the vicinity of the mouths of said ball-receiving pockets to facilitate entry of the balls into said pockets.

4. A bearing as claimed in any one of Claims 1-3 in which the or each lip tapers in a radial direction away from the body of the cage.

5. A bearing as claimed in Claim 4 in which the radial extremity of the or each is truncated and in which the arrangement is such that the inside edge of the lip makes substantially line contact with a surface of the respective race.

6. A bearing as claimed in Claim 4 or 5 in which the facing surfaces of the lip(s) and race(s) are of conical configuration, the apex angle of said conical lip surface being greater than that of said conical race surface.

7. A bearing as claimed in any one of Claims 6 in which said cage engages alternate ones of said balls, the remaining balls being engaged by a second and identical cage inserted from the opposite side of the bearing, the two cages having interdigitated ball receiving pockets.

8. A method of assembling a bearing of the kind referred to, in which the rolling elements are assembled to the bearing races and the cage is thereafter inserted from one side of the bearing into the gap between the races so as to engage with the rolling elements, the cage being of resiliently deformable material and having at least one sealing lip which, during said insertion step, makes sealing engagement with the inner or outer race of the bearing, the bearing is of the form claimed in any one of Claims 1-7.

9. A modification of the method claimed in Claim 8 in which there are two of said cages and in which each cage is inserted into the gap between the races from opposite sides of the bearing and the sealing lips thereof are brought into sealing engagement during the insertion step.