GB2341900A

GB2341900A - Cage for roller bearing

Info

Publication number: GB2341900A
Application number: GB9922365A
Authority: GB
Inventors: Klaus Muschiol
Original assignee: SKF GmbH
Current assignee: SKF GmbH
Priority date: 1998-09-28
Filing date: 1999-09-21
Publication date: 2000-03-29
Also published as: GB9922365D0; FR2783886A1; DE29817348U1; JP2000104739A

Abstract

A roller bearing, in particular a radial needle bearing, having a cage (1) with pockets (2) spaced apart on the circumference for accommodating rollers or needles (3,3') and recesses (8) to accommodate lubricant. A recess (8) is formed at each end of a pocket (2') by inserting a roller (3') which is shorter than the length of the pocket.

Description

2341900 Roller Bearing The invention relates to a roller bearing, in

particular a radial needle bearing, having a cage with pockets spaced apart on the circumference for accommodating rollers or needles and with recesses or the like to accommodate lubricant or the like.

In the field of bearing technology, applications are known in which subsequent lubrication of the bearing during operation is not possible. In such cases the bearing has to be lubricated for life, i.e. lubricant chambers have to be provided in the bearing.

A needle bearing cage is known, in which every second or third cage crosspiece (or web) is interrupted so is that only short cross-piece extensions remain for retaining the needles and the space left free by the cross-piece interruption can accommodate a grease pad (DE-GM 16 73 063).

In this embodiment, under certain conditions, the strength and stability of the cage can be weakened by the interruptions in the cross-pieces to such an extent that, under high loads and any possible vibrations occurring, the remaining cross-pieces may break or other problems may arise. Moreover, these known cages are not mass-produced parts but are special products which have high production costs.

Therefore, it is the object of the invention to devise a roller bearing of the type described in the introduction, in which lubricant reservoirs can be formed in the cage in a simple and cheap manner.

This is achieved in accordance with the invention in that a roller or needle, which is substantially shorter in length than the length of the pockets accommodating the rollers or needles, is inserted into at least one of the pockets. It is pointed out, merely for clarification, that the relevant roller or needle is substantially shorter than the otherwise normal axial pocket clearance. The space remaining in the respective pocket is filled with lubricant.

2 In the case of this solution it is possible to use a cage which is conventional for standard bearings and which can be produced inexpensively in large batch quantities. As a rule, rollers or needles of the same diameter are also produced with different lengths. Therefore, an existing roller or needle, which is shorter in length, can be inserted into one pocket or, according to another feature of the invention, into a plurality of pockets preferably uniformly spaced apart around the circumference. The cage cross-pieces are not interrupted or weakened, such that the cage can withstand heavy loads.

In the case of bearings which accommodate only radial loads, the rollers or needles are not displaced in an axial direction, i.e. the shorter roller or needle remains in the position in the pocket in which it is inserted. In the case in which axial displacement is to be expected, according to further features of the invention, measures can be taken to secure the axial position of the roller(s) or needle (s). For this purpose either the rollers or needles can be provided at at least one, or advantageously both, end faces with pegs or the like of reduced diameter, which can abut axially against the lateral surfaces of the cage side rings facing the rollers or needles.

It is also possible to provide projections or the like protruding into the pockets on the lateral surfaces of the cage side (end) rings facing the roller or needle end faces.

Finally, according to a further feature of the invention, it is possible to arrange two or more rollers or needles side by side in an axial direction in the pockets of the cage, wherein a smaller number of rollers or needles are inserted into the pockets which are intended to form the grease chambers.

Embodiments of the invention are illustrated, by way of example only, in the accompanying drawings, with reference to a needle bearing, and will be described in more detail, wherein:

3 Figure 1 is a perspective view of a part of a needle bearing cage containing needles of different length; Figure 2 is a plan view of the cage section of Figure 1, and Figures 3 and 4 are plan views of two modified embodiments of the cage, with axial guidance of the shorter needles.

The cage as shown in Figures 1 and 2 is a sleeve- like component, comprising pockets 2 which are spaced apart around its circumference. The pockets 2 are of similar dimensions for accommodating needles 3. The cage 1 thus has side (or end) rings 4 and cross-pieces 5 which connect the side rings 4, and which define the pockets 2. A needle 31, which is shorter in length than the needles 3, is inserted in one of the pockets 21 so that chambers 8 are formed at each end of the pockets 21 between needle end faces 6 and 7 and the inner lateral surfaces of the side rings 4, for accommodating lubricant.

In the modified embodiments according to Figures 3 and 4, measures have been taken to ensure that the needles 3 cannot be displaced in an axial direction. Thus in the embodiment according to Figure 3, the end faces 9 the shorter needle 31 are provided with axially projecting pegs 10 of smaller diameter than the diameter of the needles 3 and 3'. The pegs 10 abut against the inner lateral surfaces 11 of the cage side rings 4 which face the needle end faces 7.

In the embodiment according to Figure 4, projections 12 are provided on the inner lateral surfaces ill of the cage side rings 4 projecting into the pockets 2.

4

Claims

1. A roller bearing, having a cage defining pockets spaced apart around the circumference for accommodating rollers or needles and recesses to accommodate lubricant, wherein at least one roller or needle which is substantially shorter in length than the length of the pockets is inserted into at least one of the pockets to form the said recesses.

2. A roller bearing according to Claim 1, wherein a plurality of rollers or needles of shorter length are inserted into a plurality of pockets spaced apart around the is circumference of the cage.

3. A roller bearing according to Claim 1 or 2, wherein at least one projecting peg is provided for axial location of the at least one roller or needle of shorter length with the pockets.

4. A roller bearing according to Claim 3, wherein the at least one roller or needle of shorter length is formed with an axially projecting peg on at least one end faces of the roller or needle, said peg(s) being of smaller diameter than the diameter of the at least one roller or needle.

5. A roller bearing according to Claim 3, wherein the at least one projectioning peg is arranged on at least one lateral surface of the side rings of the cage which define the pockets directed axially inwards toward the end face(s) of the at least one roller or needle of shorter length.

6. A roller bearing according to any one of the preceding Claims further comprising a plurality of rollers or needles per pocket arranged axially side by side, wherein fewer rollers or needles are disposed in at least one of the pockets than in the other pockets.

7. A roller bearing substantially as hereinbefore described with reference to or as shown in the accompanying drawings.