GB2327468A

GB2327468A - Unit for method of recycling lubricant in a rolling-element bearing

Info

Publication number: GB2327468A
Application number: GB9715119A
Authority: GB
Inventors: Anthony Thomas Synnott
Original assignee: NSK European Technology Co Ltd; RHP Bearings Ltd
Current assignee: NSK European Technology Co Ltd; RHP Bearings Ltd
Priority date: 1997-07-17
Filing date: 1997-07-17
Publication date: 1999-01-27
Anticipated expiration: 2017-07-17
Also published as: GB2327468B; GB9715119D0

Abstract

A unit (15) serves to collect and recycle grease used as lubricant in a rolling-element bearing (10) supporting a spindle (11). The unit (15) is composed of several annular components (16, 17, 18) which partly surround the bearing (10). Two of the components (17, 18) have respective radial bodies (20) defining interior cavities (24) confronting the interior of the bearing (10) and axial projections (22) which engage on the outer bearing ring (13). The other annular component (16) seats snugly between the two components (17, 18) and the outer bearing ring (13) and communicates via borings (19, 28) with the interior cavities (24). During use, short bursts of air passed into the cavities (24) via the borings (19, 28) forces grease from the cavities (24) back into the interior of the bearing (10).

Description

Unit for and method of recvclin9 lubricant in a rolline-element bearing The present invention relates in general to rolling-element bearings. More particularly, the invention is concerned with a unit usable with such bearings to recycle lubricant and to a method of recycling lubricant.

It is well known that excessive packing of grease into a rolling-element bearing causes excessive churning of the grease and high temperatures which can lead to bearing failure.

An object of the present invention is to provide a unit for and a method of recycling grease adapted to overcome this problem.

In one aspect the invention provides a unit usuable with a rolling-element bearing and comprising means for creating radial barriers disposed alongside the bearing and spaced therefrom during use and passages leading to openings in the radial barriers open towards the bearing during use whereby grease displaced from the interior of the bearing can be trapped by the barriers and recycled back into the bearing by the supply of air or some other gas to the passages.

In another aspect the invention provides a method of recycling lubricant used in a rollingelement bearing said method comprising trapping displaced lubricant alongside the bearing and using jets of air or some other gas to transfer the displaced lubricant back into the bearing.

A unit constructed in accordance with the invention can be embodied as a housing fitted onto an outer ring of the bearing and the barriers can be formed by radial walls or bodies of the unit. The unit can be fabricated in composite form with a pair of separate symmetrical ring components providing the radial bodies and the barriers. Preferably the radial bodies or the equivalent barriers have cavities facing the interior of the bearing for trapping displaced lubricant and the openings are distributed uniformly around the ring components in surfaces of the cavities conveniently radial surfaces forming bases for the cavities. The passages can take the form of borings in each ring component leading to the openings to provide discrete jets of air or other gas and leading to a circumferential groove in the outer surface of the ring component. A further outer ring component can be fitted into a pocket defined by the pair of ring components. The pair of ring components can have axial projections which locate on the opposite side faces of the bearing outer ring. Outer faces of the axial projections may lie co-planer with the outer circumferential surface of the bearing outer ring to form a base for the pocket. The outer ring component may have supply bores which communicate with the circumferential grooves to supply the air or gas.

The invention may be understood more readily, and various other aspect and features of the invention may become more apparent, from consideration of the following description.

An embodiment of the invention will now be described, by way of example only, with reference to the accompanying drawings wherein Figure 1 is part-sectional side view of a unit constructed in accordance with the invention when fitted to a rolling-element bearing.

Figure 2 is a view corresponding to Figure 1 and showing the displacement and trapping of grease.

Figure 3 is a sectional side view of one component part of the unit shown in Figures 1 and 2 and Figure 4 is an end view of part of the unit.

The drawings depicts a rolling-element bearing 10 seated on a shaft or spindle 11. The rolling-element bearing 10 has an inner ring 12 rotatable with the shat 11 a stationary outer ring 13 and balls 14 as rolling elements therebetween. A unit 15 constructed in accordance with the invention constitutes a housing partly surrounding the bearing 10.

The unit 15 is composed of annular components 16, 17, 18. The component 16 takes the form of a ring with radial bores 19. Each of the components 17, 18 is also of ring-like form with a main radial wall or body 20 terminating in an axial projection 21 extending inwardly towards the bearing 10 and spaced from the inner bearing ring 12. A further axial projection 22 extends inwardly from the body 20 of each component 17, 18 to locate against the radial side faces ofthe outer bearing ring 13. The radial inner side face 23 of the body 20 of each component 17, 18 combines with the projections 21, 22 to form a cavity 24 facing the interior ofthe bearing 10. The outermost regions ofthe bodies 20 ofthe components 17, 18 have radial side faces 25 which combine with axial outermost faces ofthe outer co-planer surface ofthe bearing ring 13 and the projections 22 to provide a pocket 26 for receiving the component 16. The axial outermost faces of the projections 22 have grooves 27 which communicate with the bores 19. Further borings 28 in the bodies 20 communicate with the grooves 27 and terminate with openings 29 in the radial bases of the cavities 24. The openings 29 are distributed uniformly around the bearing 10 as shown in Figure 4. The openings 29 have a diameter of around 1 mm.

As shown in Figure 1, the bearing 10 contains deposits 30 of grease which tend to be expelled outwardly into the cavities 24 as depicted in Figure 2 to form trapped deposits 31. By supplying short pulses of gas, conveniently air, into the bores 19 and thence through the openings 29 jets of gas emitted by the openings 29 force the grease deposits 31 back into the bearing 10 as desired. The supply of air can thus be controlled to return the grease back to the bearing 10 periodically. The recycling of the grease in this manner ensures that there is always adequate grease to lubricate the bearing without excessive packing of the grease.

Claims

1. A unit usuable with a rolling-element bearing and comprising means for creating radial barriers disposed alongside the bearing and spaced therefrom during use and passages leading to openings in the radial barriers open towards the bearing during use whereby grease displaced from the interior of the bearing can be trapped by the barriers and recycled back into the bearing by the supply of air or some other gas to the passages.

2. A unit according to claim 1 wherein the barriers define cavities facing the interior of the bearing during use.

3. A unit according to claim 2 wherein the cavities are bounded by projections locatable with an outer ring of the bearing.

4. A unit according to any one of claims 1 to 3 wherein the openings have a diameter of around 1 mm.

5. A unit according to any one of the preceding claims and of composite construction with a pair of separate ring components forming the barriers.

6. A unit according to claim 5, wherein each ring component has a circumferential groove which leads through borings to the openings and providing the passages and the circumferential grooves communicate with further bores in another ring component fitted to the pair of ring components.

7. In combination a rolling-element bearing and a unit according to any one or more of the preceding claims.

8. A unit substantially as described with reference to and as illustrated in the accompanying drawings.

9. A method of recycling lubricant used in a rolling-element bearing; said method comprising trapping displaced lubricant alongside the bearing and using jets of air or some other gas to transfer the displaced lubricant back into the bearing.

10. A method of recycling lubricant substantially as hereinbefore described.