GB2533302A

GB2533302A - Lubricant distribution in a roller bearing

Info

Publication number: GB2533302A
Application number: GB1422291.3A
Authority: GB
Inventors: Holsnijders Jos
Original assignee: SKF AB
Current assignee: SKF AB
Priority date: 2014-12-15
Filing date: 2014-12-15
Publication date: 2016-06-22
Also published as: WO2016096431A1

Abstract

A lubricant distribution element 8 is designed for use in a roller bearing 1 comprising a cage 4. The lubricant distribution element 8 is configured for being mounted on the cage 4 adjacent to an end surface 52 of a roller 5 and for guiding lubricant towards an edge of the roller during operation of the bearing. The element may be a snap fit on the cage and swivel relative to the cage. The element may have a lubricant guiding surface 81 which extends in a plane of the end surface 52 of the roller. The element may be plastic i.e. nylon or polyethylene and manufactured by 3D-printing or injection moulding.

Description

Lubricant distribution in a roller bearing

Field of the Invention

The present invention relates to a lubricant distribution element for a roller bearing. More in particular, the present invention relates to a lubricant distribution element for improving the lubrication of a roller bearing.

Background of the Invention

It is well known to provide lubrication in bearings. Various types of greases or other lubricants may be used in bearings. In a typical bearing, however, the lubricant is not uniformly distributed during use. The lubricant tends to collect in certain parts of the bearing, for example on the end surfaces of the rollers, or behind cage parts, thus reducing the amount of lubricant actually available for lubricating the friction surfaces. It will be clear that this is undesired.

Summary of the Invention

It is an object of the present invention to solve these and other problems of the prior art by providing a lubricant distribution element for a roller bearing, which lubricant distribution element provides a better lubricant distribution.

Accordingly, the present invention provides a lubricant distribution element for use in a roller bearing comprising a cage, which lubricant distribution element is configured for being mounted on the cage adjacent to an end surface of a roller and for guiding lubricant towards an edge of the roller during operation of the bearing.

By providing a lubricant distribution element which is designed for guiding lubricant towards an edge of a roller, the lubricant collecting on the end surface of the roller will be moved towards the roller's edge and therefore towards the roller's side surface. In this way, the lubricant in the bearing is re-distributed and used more effectively.

Although the lubricant distribution element may be mounted in various ways, it is preferred that it is configured for snap-fitting onto the cage. To this end, the cage may have a section suitable for mounting the lubricant distribution element. If the cage is a wire cage, the lubricant distribution element may be directly snap-fitted onto a wire section extending over the end surface of a roller. A wire cage may have various designs, for example a meandering wire case as disclosed in United States Patent US1389385. The lubricant distribution element may advantageously be arranged for being able to swivel relative to the cage, for example swivel about the part if the cage on which it is mounted. This ability to move about the cage section on which it is mounted allows the lubricant distribution element to adjust to different quantities of lubricant.

It is preferred that the lubricant distribution element is provided with a lubricant guiding surface which extends, in the plane of the end surface of the roller, away from the rotational axis of the roller. A lubricant guiding surface which extends away from the rotational axis of the roller, that is, beyond the rotational axis, will urge, due to the rotation of the roller, any lubricant towards the roller's edge and hence to the roller's side surface. It is further preferred that the lubricant guiding surface is bordered, at an edge furthest from the roller, by a protruding ridge extending in parallel with an end surface of the roller.

The lubricant distribution element may be made of a synthetic polymeric material, for example but not limited to nylon or ultra-high-molecular-weight polyethylene (UHMWPE). The lubricant distribution element may be made by injection moulding, for example, but may also be made by additive manufacturing (also known as 3D printing).

The present invention also provides a roller bearing comprising a cage and rollers, provided with a lubricant distribution element as described above. A roller bearing according to the present invention may further comprise separators for separating the rollers, the separators being provided with flanges for collecting lubricant from the end surface of the rollers and urging the collected lubricant towards a side surface of the rollers. Such separators are particularly advantageous as they cooperate with the lubricant distribution elements to distribute the lubricant and transport it to the side surfaces of the rollers. Advantageously, the flanges may be designed to extend over the respective end surface of a roller so as to have a spacing relative to the roller which decreases in the direction of revolution of the roller. This provides an even better lubricant distribution as the decreasing spacing in the direction of the rotation assists in urging the lubricant towards the side surfaces of the rollers.

Although various types of cages may be used with the lubricant distribution element of the present invention, the element is particularly suitable for a wire cage, as such a case typically allows a snap-on mounting without any alterations to the cage. An example of a wire cage is a cage comprising a meandering wire constituting an interrupted first ring, an interrupted second ring and connecting sections extending between the interrupted rings, the connecting sections defining spaces for receiving rollers of the roller bearing.

The present invention also provides a machine provided with a bearing as described above.

Brief description of the drawings

The present invention will further be explained with reference to exemplary embodiments illustrated in the drawings, in which: Fig. 1 schematically shows, in perspective, a roller bearing suitable for mounting lubricant distribution elements according to the present invention.

Fig. 2 schematically shows, in perspective, part of the roller of Fig. 1 provided with a lubricant distribution element according to the present invention.

Fig. 3 schematically shows, in side view, a lubricant distribution element according to the present invention.

Fig. 4 schematically shows, in perspective, a lubricant distribution element according to the present invention with one roller.

Fig. 5 schematically shows, in side view, a separator for use with the lubricant distribution element according to the present invention with a roller.

Detailed description of embodiments

The bearing 1 illustrated in the cutaway view of Fig. 1 comprises an inner race 2, an outer race 3, a cage 4, rollers 5 and a seal 7. Part of the outer race 3 and of the seal 7 is not shown in Fig. 1 to better illustrate the rollers 5 and the cage structure 4.

The cage 4 is shown to be constituted by a meandering wire and is provided with separators 6. The meandering wire is shown to constitute an interrupted first ring, an interrupted second ring and connecting sections extending between the two interrupted rings. The interrupted or partial rings are parallel to each other, while the connecting sections extend substantially perpendicularly relative to the planes of the rings. The meandering shape of the wire provides spaces for accommodating the rollers 5. As can be seen in Fig. 1, the rollers 5 are separated by the separators 6 which also space the meandering wire apart from the rollers. In the embodiment of Fig. 1, therefore, there is no direct contact between the cage 4 and the rollers 5, thus avoiding friction.

The separators 6 are preferably mounted to the wire 4 by way of snap fittings. These snap fittings allow the separators 6 to swivel relative to the wire cage, thus allowing the cage some flexibility to adapt to pressure exerted by the rollers and thereby to further reduce friction. In addition, the snap fittings allow the separators to be easily mounted and removed. This is particularly advantageous when one or more separators have to be replaced. It further allows all separators to be replaced so as to adapt the cage to rollers having a different shape and/or different dimensions.

The separators may be designed to match the shape and dimensions of the rollers, and different separators may be provided to fit different rollers. Instead of the cylindrical rollers shown in Figs. 1, tapered rollers may for example be provided, together with matching separators.

A bearing, for example the bearing 1 of Fig. 1, may in accordance with the present invention be provided with one or more lubricant distribution elements, as illustrated in Fig. 2.

The bearing 1 shown in Fig. 2 from which the inner race has been omitted for the sake of clarity of the drawing, is provided with a lubricant distribution element 8 according to the present invention. The lubricant distribution element 8 is in the present embodiment mounted on the wire cage 4 by means of a snap-fit. As can be seen, the lubricant distribution element 8 is mounted approximately at the rotational axis of the roller 5 and extends beyond that axis. More in particular, the lubricant distribution element 8 is shown to be shaped so as to guide lubricant away from the rotational axis, towards the edge of the end surface 52 of the roller 5. In the embodiment of Fig. 2, the lubricant distribution element 8 is substantially pointed, however, more rounded embodiments can also be envisaged.

The path of lubricant in the bearing 1 is in Fig. 2 indicated by an arrow. Any lubricant reaching the lubricant distribution element 8 will, due to the rotation of the roller 5 and the shape of the lubricant distribution element 8, be guided towards the edge of the end surface 52. There the lubricant is collected by a flange 64 of a separator 6, as will later be explained in more detail with reference to Fig. 5. The flange 64 collects the lubricant from the edge of the end surface 52 and guides it towards the side surface 51.

It will be understood that the lubricant distribution element 8 can also be used without a separator 6 having suitably shaped flanges 64, but that the lubricant distribution effect of the element 8 is enhanced by such a separator. Accordingly, it is preferred that a lubricant distribution element 8 cooperates with a suitably shaped separator 6.

In the side view of Fig. 3, it can be seen that the lubricant distribution element 8 has a keyhole-shaped opening 88 for receiving, and snap-fitting onto, the cage (4 in Figs. 1 & 2). The lubricant distribution element 8 further comprises a lubricant guiding surface 81 which is bordered by a protruding ridge or flange 82. Comparing Figs. 2 & 3, it can be seen that the protruding ridge 82 extends in parallel with and over the end surface (52 in Fig. 2) of a roller. As the ridge 82 is located at the edge of the guiding surface which is furthest away from the corresponding roller, the lubricant will be contained between the ridge 82 and the end surface of the roller, thus enhancing the lubrication distribution.

The perspective view of Fig. 4 also shows the keyhole-shaped opening 88, the lubricant guiding surface 81 and the protruding ridge 82. In the embodiment of Fig. 4 the guiding surface 81 is substantially pointed, having slightly concave surface parts, but in other embodiments the guiding surface may be more rounded, or have straight surface parts.

The separator 6 of Fig. 5 is provided with flanges 64 for collecting and distributing lubricant.

As shown in Figs. 2 and 5, these flanges extend beyond the rollers and collect lubricant from the top/bottom end surfaces 52 of the rollers 5, as indicated by the arrow D. In addition, these flanges 64 are shaped so as to move lubricant from the end surface 52 of a roller, via the roller edge 53 to the roller's side surface 51.

As mentioned above, the flanges 64 of the separator 6 extend partly over the top end surfaces 52 to collect lubricant which has collected there. To this end, the flanges 64 have a distance to the top end surface 52 which varies in the rotational direction of the roller 5 so as to provide a funnel for collecting and guiding lubricant. The funnel-shaped flanges 64 may force collected lubricant into channels formed between the separator 6 and the roller 5, which channels lead towards the side surface 51 of the roller so as to redistribute lubricant and bring it to the side surface.

The lubricant distribution elements 8 of the present invention are preferably made of plastic, such as UHMWPE, but may also be made of other materials. They may be made by injection molding or by additive manufacturing.

The present invention is based upon the insight that the lubrication of a roller bearing can be significantly improved by providing lubricant distribution elements which are designed to move lubricant towards the side surface of the roller. The present invention benefits from the further insight that a lubricant distribution element may advantageously be mounted on a wire section of a bearing cage, and that using a snap-fit allows the lubricant distribution element to be easily installed and removed, and further allows the element a limited freedom to move and thereby to self-adjust.

It will be understood that the description of the invention given above is not intended to limit the invention in any way; neither are reference numbers in the claims. Singular nouns and the articles "a" and "an" are of course not meant to exclude the possibility of plurals.

It will further be understood by those skilled in the art that the present invention is not limited to the embodiments mentioned above and that many additions and modifications are possible without departing for the scope of the invention as defined in the appending claims.

Claims

Claims 1. A lubricant distribution element (8) for use in a roller bearing (1) comprising a cage (4), which lubricant distribution element (8) is configured for being mounted on the cage (4) adjacent to an end surface (52) of a roller (5) and for guiding lubricant towards an edge of the roller during operation of the bearing.
2. The lubricant distribution element according to claim 1, configured for snap-fitting onto the cage (4).
3. The lubricant distribution element according to claim 1 or 2, configured for being able to swivel relative to the cage (4).
4. The lubricant distribution element according to any of the preceding claims, provided with a lubricant guiding surface (81) which extends, in the plane of the end surface (52) of the roller (5), away from the rotational axis of the roller.
5. The lubricant distribution element according to claim 4, wherein the lubricant guiding surface (81) is bordered, at an edge furthest from the roller, by a protruding ridge (82) extending in parallel with an end surface (52) of the roller (5).
6. The lubricant distribution element according to any of the preceding claims, which is made of plastic.
7. The lubricant distribution element according to any of the preceding claims, which is made by additive manufacturing.
8. A roller bearing (1) comprising a cage (4) and rollers (5), provided with a lubricant distribution element (8) according to any of the preceding claims.
9. The roller bearing according to claim 8, further comprising separators (6) for separating the rollers (5), the separators being provided with flanges (64) for collecting lubricant from the end surface (52) of the rollers (5) and urging the collected lubricant towards a side surface (51) of the rollers.
10. The roller bearing according to claim 9, wherein the flanges (64) are designed to extend over the respective end surface (51) of a roller (5) so as to have a spacing relative to the roller which decreases in the direction (D) of revolution of the roller.
11. The roller bearing according to any of claims 8-10, wherein the cage (4) comprises a meandering wire constituting an interrupted first ring, an interrupted second ring and connecting sections extending between the interrupted rings, the connecting sections defining spaces for receiving rollers of the roller bearing.
12. The roller bearing according to claim 11, wherein a lubricant distribution element (8) is mounted on a section of the interrupted first ring.
13. A machine provided with a roller bearing (1) according to any of claims 8-12.