AU656539B2 - Bearing with lubricating and non-lubricating spacers - Google Patents

Description

'v 1 1 OPr DATE 16/03/93 AOJP DATE 27/05/93 APPLN. ID 87432/91 PCT NUMBER PCT/US91/05958 AU9187432 1 "RJtiA -1 J1'4-1 z-rrim.H.n~i1- n-,i a .(PCT) (51) International Patent Classification 5 (11) International Publication Number: WO 93/04293 F16C 19/40, 33/51, 33/66 Al (43) International Publication Date: 4 March 1993 (04.03.93) (21) International Application Number: PCT/US91/05958 Published With international search report.

(22) International Filing Date: 21 August 1991 (21.08.91) (71) Applicant: BALANCED ENGINES, INC. [US/US]; 702 Street, Tacoma, WA 98402 6 (72) Inventor: ZORNES, David, A. 801 212th Avenue N.E., Redmond, WA 98053 (US).

(74) Agents: SEED, Richard, W. et al.; Seed and Berry, 6300 Columbia Center, Seattle, WA 98104-7092 (US).

(81) Designated States: AU, BR, CA, JP, KR, European patent (AT, BE, CH, DE, DK, ES, FR, GB, GR, IT, LU, NL,

SE).

(54) Title: BEARING WITH LUBRICATING AND NON-LUBRICATING SPACERS j1F"FI (57) Abstract A bearing has a plurality of rolling elements in a raceway, which are separated by lubricating spacer elements (101) and non-lubricating spacer elements (102). The lubricating spacer elements are free to float between the rolling elements and can provide all of the lubrication for the bearing. The non-lubricating spacer elements may also be free to float between the rolling elements or can be provided by a cage, II-- I j I 4 S. *t S S S

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a 55545* BEARING WITH LUYBRICATING AND NON-LUBRICATING SPACERS This ir-vention relates to self-lubricating bearings of the type in which the roller elements are lubricated by lubricant transfer from spacers containing lubricants.

U.S. patent. no. 4,906,110 discloses an improved solid lubricant roller bearing in which the rollers are separated by floating lubricating spacers. An object of the present invention is to increase the life and stability of this type of bearing.

According to the present invention there is provided a bearing comprising: means providing a race-way; a plurality of rolling elements in said race-way; non-rolling spacer elements in said race"-way between axd closely adjacent to said rolling elements for maintaining a pre-determined minimum spacing therebetween; and lubricating spacer elements in said race-way between said rolling 25 elements, said lubricating spacer elements being free to float independently of said rolling elements and non-rolling spacer elements and being arranged so that each lubricating spacer element can be engaged by the two adjoining of said rolling elements, characterised in that, said non-rolling spacer elements being non-floating and arranged to be engaged by said rolling elements when maintaining said minimum spacing.

941110,p:\oper\kay,87432.spe,1 1 r At ANNEX TO THE INTERNATIONAL SEARCH REPORT ON INTERNATIONAL PATENT APPLICATION NO. US 9105958 SA 52565

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-2- An embodiment of the invention will now be described by way of example only with reference to the accompanying drawings in which:- Figure 1 is an exterior side view of an assembly of spacer and roller elements; Figure 2 is an end view of the assembly with an annular end ring removed; Figure 3 is a detailed end view taken as in Figure 2; Figure 4 is an isometric exploded view of a portion of a bearing; Figure 5 is an exploded isometric view of a spacer and roller configuration; Fi.-ure 6 is an alternate embodiment of a spacer for use with the rollers.

Figure 7 is a fragmnentary plan view of a first embodiment of the invention utilizing a crage; Figure 8 is a transverse sectional view taken as shown by lines 8-8 in Figure 7; and Figure 9 is a fragmentary end view of the first embodiment.

To aid in the understanding of the embodiment of the invention shown in Figures 7 to 9, a description of the arrangements shown in Figures 1 to 6 will now be given.

Referring to Figures 1-2, floating spacers 1 having a solid lubricant composition separate an equal number of rolling needle elements 2. Each spacer 1 is preferably machined or molded to provide concave opposite sides 3, 5 with a curvature similar to the outer surface 4 44, 94111,p%opr\kay,87432.spe,2 0 ta *0 0 77 -w 4- -1 I c- WO 93/04293 PCT/US91/05958 3 of the needle rolling elements 2 to provide a relatively large initial contact ar(?.a for solid lubricant transfer thereto. The outer and inner surfaces 6, 7 of the spacers 1 may be molded or machined with a convex curvature to conform, respectively, to that of the inner and outer raceways, as determined by diameters 8, 9, or the surfaces 6, 7 may be planar and have two-line contact along the longitudinal edges of outer surface 6 with the outer raceway and single-line tangential contact with the inner raceway midway between the longitudinal side edges of inner surface 7. End lubrication of the rolling elements 2 may be accomplished, for example, by annular rings 100 of solid lubricant material positioned adjacent the ends of the rollers 2 and spacers i, or by end caps of solid lubricant material mounted on the ends of the rollers, or by end portions of the spacers arranged to overlap the ends of the rollers.

For cost economy it is preferred to form the spacers 1 by a high-pressure compaction and secondary sintering procedure precluding a need for follow-up machining. The joints at the meeting ends of adjoining spacer elements et opposite sides of each roller may be staggered endwise of the roller, so that each portion of the roller circumference will directly contact a spacer element during each roller rotation. This end can be accomplished, for example, by beveling the adjoining ends of the spacers to provide sloped end faces. By this arrangement the joint lines between respective spacer elements at opposite sides of a roller are staggered relative to one another along the roller.

Referring to Figure 3, a recess 10 with angle 11 is preferably provided in the spacer elements along a plane 12 passing through the center axis of the adjoining rolling elements 2. This recess angle 11, as measured with respect to a plane 13 passing through the rotary axis of the bearing and the rotary axis of the adjoining rolling element, typically has a value of 30 degrees and

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-tt -4will ensure that wear particles separated from the spacer are of minimum size so as not to interfere with the smooth operation of the bearing. The recess also serves to recapture small, loose wear particles of transfer lubricant and consolidate the particles back into the body of the spacer under the compressive action occurring between the rolling elements and the spacer with respect to the apex of the recess angle 11.

In the spacer element 10, shown in Figure 6, the recesses 10' are relieved so as to be substantially concave. This modification encourages wear particles to be captured in the recesses 10' rather than becoming entrapped between relative moving surfaces of the assembly.

Non-lubricating spacers may also be provided. It is preferred to alternate spacer elements containing solid lubricant substances ("lubricating spacer elements") with spacer elements which do not have lubrication as their principal function ("non-lubricating spacer elements") and preferably are more resistant to wear from roller contact. If both the lubricating and non-lubricating spacer elements are floating, they preferably are alternated in both the axial roller direction and S: circumferential direction of rotation of the entire bearing assembly. This arrangement maintains proper alignment and spacing of the roller elements by way of the non-lubricating spacers as the lubricating spacer segments are consumed. In this regard the initial clearances can be such that only the lubricating spacers contact the rollers until a preset amount of wear of the lubricating spacers has occurred.

referred materials for the "non-lubricating" spacer elements include, but are Snot limited to such hard wearing materials as ceramic materials, non-lubricated polymide materials, steel, silver impregnated bronze, phenolic materials, nylon, etc.

"The "non-lubricating" spacer elements may also be made from relatively soft 94111p:oper\kqy,87432.pe,4 1 WO 93/04293 PCT/US91/05958 materials such as Teflon®, phenolic materials, nylon, etc.

for low load conditions.

A basic arrangement of lubricating and nonlubricating spacer elements denoted 101 and 102, respectively, is shown in Figure 4 for adjacent spacers.

Spacer la, for example, has a pair of lubricating spacer elements 101 separated by a non-lubricating spacer element 102, whereas spacer Ib has a pair of non-lubricating spacer elements 102' separated by a lubricating spacer element 101'. Each of the lubricating spacer elements are preferably longer than the non-lubricating spacer elements so that the full length of the related roller will always be in contact with lubricating spacer elements. However, this arrangement is not essential because the lubricant spreads across the races and rollers 'responsive to rotation of the rollers.

The illustrated arrangement of alternating lubricating and non-lubricating spacers in Figure 4 provides each roller (roller for example) with two non-lubricating roller elements 102' adjacent its ends at one side of the roller, and with a central non-lubricating roller 102 at the other side of the roller. This assures stability to the rollers by the non-lubricating spacers.

Referring to Figure 5, the spacer Ic can provide end lubrication for the roller 2 by having the spacer ends cover the ends of the cavity with which the rollers interfit. Also, the rollers 2 can comprise a series of Sroller elements 2a placed end-to-end. As in the Figure 4 example, non-lubricating spacer elements are alternated with lubricating spacer elements. At one side of the roller 2 spacer Ic has a pair of lubricating spacer Y elements 101'' which are opposed by a shorter pair of nonlubricating spacer elements 102'' in spacer id at the other side. Further, in spacer id center lubricating spacer element 101"' opposes a central non-lubricating spacer 102''' in spacer Ic.

I -6- In Figures 4 and 5, the spacers la-ld have been shown as each consisting of three spacer elements. It will be understood, that there can be a greater number of spacer elements in each spacer, preferably an odd number of elements in each which are arranged so that lubricating spacer elements alternate with nonlubricating elements in each spacer and are positioned opposite a nonlubricating spacer element in the adjacent spacers.

The lubricating spacer elements may be made from Vespel* SP-21 polymide, a commercially available product produced by the DuPont Company having U.S.

Military Specification R46198. This product does not soften and is thermally resistant such that it can carry loads at temperatures beyond the reach of most plastic materials and do so while exhibiting very low creep. For example, when the product is subjected for 100 hours to loads of 2,500 psi at 572 F, the total deformation is only At the end of 600 hours under these load and temperature conditions the total deformation only increases to Vespel* SP- 21 has a polymide matrix containing a dispersion of various solid lubricant substances such as graphite and Teflon. The lubricating spacer elements are made by high-pressure compaction of Vespel* powder and secondary sintering. The S: highest strength and lowest thermal expansion are usually found in the direction 20 perpendicular to the pressing direction. Vespel* SP-21 may be used for spacer elements to be used at lower temperatures. Initially there may be less tolerance provided between the lubricating spacer elements and the rollers than between the 1 non-lubricating spacers and the rollers. After use has commenced, the lubricant from the lubricating spacer elements spreads over the rollers and the non- 25 lubricating spacer elements.

Figures 7-9 illustrate an embodiment of the invention. The non-lubricating spacers may be provided by a cage 200 having end rings S 4' 941110,p\oper\ky,832spe,6

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''e \ivo 93/04293 PCT/US91/05958 200a, 200b from which non-lubricating spacer elements 202 project inwardly parallel to the axis of the bearing.

Roller elements 2 have their opposite end portions positioned between circumferentially adjoining of the elements 202 and floating lubricating spacer elements 201, are located between the roller elements 2 and between the ends of the non-lubricating spacer elements 202. To tie the end rings 200a, 200b together some of the elements 202 at opposite sides are connected by connecting elements 203. These connecting elements 203 may be alternated circumferentially of the bearing with the lubricating spacer elements 201, or the connecting elements 203 can be at less intervals so that more lubricating spacer elements are provided. Needle roller elements are normally slightly tapered inwardly slightly toward the ends and so the race engaging portion of the roller elements is normally a central part of the length. Accordingly, the lubricating spacer elements 201 concentrate application of lubricant to the "working" part of the roller elements while the non-lubricating spacer elements 202 maintain the roller elements in proper alignment. However, during operation lubricant from the lubricating spacer elements normally migrates over the entire length of the roller elements.

Normally the cage 200 will be constructed of two halves which initially are flat. The roller elements and lubricating spacer elements can be loaded into the cage halves while they are flat, and then the cages are each bent into a semi-cylindrical shape. The cross-sectional shape of the transverse non-lubricating spacer elements of the cage can be made such as to retain the end portions of the roller elements after the cage halves have been bent into their final shape. The cage may be made of silver impregnated bronze or other suitable materials.

Although it is preferred to maximize the initial roller contact surface of the lubricating spacer elements, this is not essential. Accordingly, the lubricating r .f4t4 "C~31 ilr

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-8spacer elements could have a square or trapezoidal transverse cross-section for example.

Although I have shown and described specific embodiments of my invention, it will be apparent that many minor changes of structure and operation could be made without departing from the spirit of the invention as defined by the scope of the appended claims.

Throughout this specification and the claims which follow, unless the context requires otherwise, the word "comprise", or variations such as "comprises" or "1comprising", will be understood to imply the inclusion of a stated integer or group of integers but not the exclusion of any other integer or group of integers.

99 9 9 9 9* .9 9 9 9 9*99 .9 *9* *9 9. 9 9 9* 9 9.99 99 99 9.

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Claims (11)

1. A bearing comprising: means providing a race-way; a plurality of rolling elements in said race-way; non-rolling spacer elements in said race-way between and closely adjacent to said rolling elements for maintaining a pre-determined minimum spacing therebetween; and lubricating spacer elements in said race-way between said rolling elements, S.said lubricating spacer elements being free to float independently of said rolling elements and non-iolling spacer elements and being arranged so that each lubricating spacer element can be engaged by the two adjoining of said rolling elements, characterised in that, said non-rolling spacer elements being non-floating and arranged to be engaged by said rolling elements when maintaining said minimum spacing.

2. A bearing according to claim 1 in which said non-rolling spacer elements project from end rings.

3. A bearing according to claim 1 in which a cage provides said non-rolling spacer elements.

4. A bearing according to claim 1 in which said non-rolling spacer elements are located at both ends of said lubricating spacer elements.

A bearing according to claim 1 in which said lubricating spacer elements provide substantially all of the lubrication for the rolling surface of said rolling elements.

6. A bearing according to claim 1 in which there is clearance between said rolling elements and said non-rolling spacer elements and lubricating spacer S94i29,p:\oper\kay,87432.spe,9 i i I n, s" a! elements.

7. A bearing according to claim 1 in which said race-way is defined by circular inner and outer races, and said rolling elements each have a race-engaging central portion, said lubricating spacer elements being located between said central portions of the rolling elements to apply lubricant thereto, and said non-rolling spacer elements being located endwise of said lubricating spacer elements.

8. A bearing according to claim 7 in which said non-rolling spacer elements are portions of a cage having end rings located endwise of the ends of said rolling elements.

9. A bearing according to claim 1 in which said race-way is circular and the rolling elements alternate with said lubricating spacer elements at a central portion of the rolling elements, and in which the rolling elements alternate with said non- rolling spacer elements endwise of said central portion and lubricating spacer elements.

10. A bearing according to claim 1 in which said race-way is circular and in 20 which each roller element is arranged to engage at least three non-rolling spacer elements and at least two lubricating spacer elements.

11. A bearing substantially as hereinbefore described with reference to the accompanying drawings. DATED this 10th day of November 1994 Balanced Engines, Inc. By Its Patent Attorneys DAVIES COLLISON CAVE Ca U, U U U.. U ao *n .9 aC S C) O tD o 0 0 .06 50 00005 o 0 I I Ir K J~.i /Z1: :I: 41i 'I 9411 10,p: \oper1ay,7432spe, 10