FR2749048A1 - COVER FOR A BEARING - Google Patents

Abstract

Cover for bearings of tensioning devices or the like, comprising latching elements 10 distributed around the periphery and penetrating into a radial groove 7, and parts for centering and axial support against the bearing. The cover comprises immobilizing projections 11 directed radially, distributed over the periphery and applied under prestressing against a peripheral surface 5 of the bearing, in order to immobilize the cover in rotation with respect to part 3 of the bearing receiving the cover. Preferably, the immobilizing protrusions 11 are arranged in the flexion region of the latching elements 10 and are wedge-shaped in the circumferential direction. Application: In particular to belt tensioners.

Description

1. "Cover for a bearing" The invention relates to a cover for a

  a bearing of a tensioning device or the like comprising ratchet elements distributed around the circumference and engaging in a radial groove, and parts for

  centering and axial support against the bearing.

  Lids of this type are used to protect roller bearings or other

  bearings of tensioning devices, for example for

  roies, against the penetration of dust, water and other foreign bodies. These lids are fixed by

  example, to the outer ring or to the part of

  mounting of the bearing by latching elements. A simple solution uses a radial groove in which latching elements of the lid engage

  made of a single piece of plastic material by

  injection. The radial groove generally comprises

  oblique flanks, which allows stabilization

  lid and a good seal. The shape of the lid is chosen according to the mounting conditions, the lid being disc-shaped or bucket-shaped so as to cover the entire mounting space and the front side of the axis, etc. A lid that is held on the bearing without a prediction of a groove on the latter is known,

  for example, by the utility model DE-93 478.

  To prevent the cover from rotating in the groove, which could compromise the seal,

  an important radial clamping effect is sought

  both by a dimensionnemment corresponding. This, however, makes mounting difficult and often leads to undetectable damage to the lid, causing

waterproofness problem.

  The object of the present invention is to provide a cover of the type defined in the preamble which can be mounted in a simple manner while being immobilized in

  reliable rotation and ensuring good

  chéité. This object is achieved by the fact that the lid has radially directed rotational immobilization projections distributed around the circumference and

  applied under prestressing against a perimeter

of the plateau.

  Preferably, the immobilization projections are wedge shaped profiled projections disposed

  in the bending region of the detent elements.

  Other features of the lid according to the invention will become apparent on reading an example of

  illustrated by the accompanying drawings, on the

  which: - Figure 1 is a partial longitudinal section of a bearing with cover for a tensioner roller; - Figure 2 shows on a larger scale the detail X of Figure 1, relating to the fixing of the cover; - Figure 3 is a partial cross section

following A-A of Figure 2.

  The tensioning roller illustrated by the figures

  takes a bearing whose inner ring 1 is

  in a manner not shown in detail on an axis

  carrier 2 and whose outer ring 3 bears a

  4. A peripheral portion of the surface (outer lateral surface) 5 of the outer ring 3 is disengaged, that is to say not occupied by the ring 4, this part being provided to receive a cover 6. For this purpose, a radial groove 7 is formed in the outer ring 3, in said part

of surface.

  The lid 6 is substantially bucket-shaped, one-piece plastic, with an annular flat outer annular portion 8 flange or flange. On this part 8 is formed a

  extension or cylindrical tip 9 which presents

  radially annular bead 10 whose

  profile is adapted to the profile of the radial groove 7.

  Between the radial bead 10 and the portion 8 in the form of a flange, the nozzle 9 has internally, as shown in Figures 2 and 3, several immobilization projections 11 distributed over the inner periphery. In the circumferential direction, these projections are relatively narrow and have a wedge profile. In the example shown, three of these immobilization projections 11 are offset by 120

  degrees to each other.

  When placing the lid 6, the

  cylindrical end 9 first undergoes elastic expansion

  that, thanks to its input chamfer 12, before the radial bead 10 engages in the radial groove 7 and pulls the cover 6, by the oblique sides 13 of the radial groove 7, until the application of the outer annular portion 8 against the front face 14 of the

outer ring 3.

  The high restoring forces of the expanded cylindrical nozzle 9 cause a crushing almost

  complete set of three immobilization projections 11 of

  volume on the corresponding part of the lateral surface 5 of the outer ring 3. It thus occurs, at the location of the immobilizing projections 11, so at three locations distributed around the periphery, a

  very high surface pressure on the outer ring

  3, ensuring in an extremely efficient way the immobilization in rotation of the cover on the ring

3, by clamping effect.

  It would also be possible, in the context of the invention, to give the cylindrical nozzle 9 and the radial bead 10 provided on this nozzle, not the

  circular shape described, but the shape of segments in-

  dependent separated by slits.

Claims (2)

  1.- Lid for bearings of devices   tensioning members or the like, comprising latching elements distributed around the periphery and penetrating into a radial groove, and parts for centering and axial support against the bearing, characterized by the   fact that it includes, in addition, projections of immobili-   radially directed (11), distributed around the circumference and applied under prestress against a peripheral surface (5) of the bearing, to immobilize the cover (6) in rotation relative to the portion (3). of the bearing receiving the cover.   2. Lid according to claim 1,   characterized by the fact that the immobilization protrusions   (11) are arranged in the flexion zone of the   latching elements (10) and are shaped in the form of   corner in the circumferential direction.