Tapered oil feed bearing cage

• US 9,194,432 B2
• Filed: 07/16/2014
• Issued: 11/24/2015
• Est. Priority Date: 08/06/2013
• Status: Active Grant

• Current Assignee: Rolls-Royce PLC (Rolls-Royce Holdings Plc)
• Original Assignee: Rolls-Royce PLC (Rolls-Royce Holdings Plc)
• Inventors: Ashmore, Daren Richard, Plant, James Alan, Morton, Graham Paul
• Primary Examiner(s): Hannon, Thomas R.
• Application Number:
  US14/332,435
• Publication Number:
  US 20150043851A1
• Time in Patent Office: 496 Days
• US Class Current: 1/1
• CPC Class Codes: F01D 25/16 Arrangement of bearings; Supporting or mounting bearings in casings bearings per se F16C
• CPC Class Codes: F01D 25/18 Lubricating arrangements of machines or engines in general F01M
• CPC Class Codes: F02C 7/06 Arrangements of bearings bearings F16C; Lubricating of turbo machines F01D25/18; of machines or engines in general F01M
• CPC Class Codes: F05D 2250/292 tapered
• CPC Class Codes: F16C 19/06 with a single row or balls
• CPC Class Codes: F16C 19/26 with a single row of rollers
• CPC Class Codes: F16C 2360/23 Gas turbine engines in general F02C
• CPC Class Codes: F16C 33/385 made from metal, e.g. cast or machined window cages
• CPC Class Codes: F16C 33/4605 Details of interaction of cage and race, e.g. retention or centring
• CPC Class Codes: F16C 33/4623 formed as one-piece cages, i.e. monoblock cages
• CPC Class Codes: F16C 33/467 Details of individual pockets, e.g. shape or roller retaining means
• CPC Class Codes: F16C 33/4676 of the stays separating adjacent cage pockets, e.g. guide means for the bearing-surface of the rollers
• CPC Class Codes: F16C 33/583 Details of specific parts of races
• CPC Class Codes: F16C 33/586 outside the space between the races, e.g. end faces or bore of inner ring
• CPC Class Codes: F16C 33/6614 in recesses or cavities provided in retainers, races or rolling elements
• CPC Class Codes: F16C 33/664 Retaining the liquid in or near the bearing
• CPC Class Codes: F16C 33/6659 Details of supply of the liquid to the bearing, e.g. passages or nozzles
• CPC Class Codes: F16C 33/6677 from radial inside, e.g. via a passage through the shaft and/or inner ring
• CPC Class Codes: F16C 33/6681 Details of distribution or circulation inside the bearing, e.g. grooves on the cage or passages in the rolling elements

Abstract

A bearing cage for a rolling element bearing assembly includes an outer surface, an inner surface defining a bore, and a plurality of pockets. Each pocket of the plurality of pockets is configured to house a rolling element of the rolling element bearing assembly. The plurality of pockets are arranged sequentially around the bearing cage with respect to an axis of the bore. A guide portion of the inner surface is tapered in an axial direction of the bore such that dimensions of the bore increase towards a central region of the bore, and the bearing cage further includes a plurality of conduits providing fluidic communication between the inner surface of the bearing cage and the outer surface of the bearing cage.

Claims

1. A bearing cage for a rolling element bearing assembly, the bearing cage including

an outer surface;

an inner surface defining a bore; and

a plurality of pockets, each pocket of the plurality of pockets being configured to house a rolling element of the rolling element bearing assembly, the plurality of pockets being arranged sequentially around the bearing cage with respect to an axis of the bore, wherein

a guide portion of the inner surface is tapered in an axial direction of the bore such that dimensions of the bore increase towards a central region of the bore, and

the bearing cage further includes a plurality of conduits providing fluidic communication between the inner surface of the bearing cage and the outer surface of the bearing cage.

2. The bearing cage for a rolling element bearing assembly according to claim 1 wherein the guide portion of the inner surface is tapered in the axial direction of the bore, and from each end of the bore, such that the dimensions of the bore increase towards a central region of the bore.

3. The bearing cage for a rolling element bearing assembly according to claim 1 wherein the plurality of pockets are arranged around a circumferential portion of the central region.

4. The bearing cage for a rolling element bearing assembly according to claim 1, wherein each pocket of plurality of pockets extends fully between the inner surface and the outer surface of the bearing cage.

5. The bearing cage for a rolling element bearing assembly according to claim 1, wherein the dimensions of the bore include a diameter or a radius of the bore.

6. The bearing cage for a rolling element bearing assembly according to claim 1, wherein, in use, the conduits do not house any of the rolling elements.

7. The bearing cage for a rolling element bearing assembly according to claim 1, wherein at least one conduit is provided for each respective pocket.

8. The bearing cage for a rolling element bearing assembly according to claim 1, wherein at least two conduits are provided for each respective pocket, each respective pocket being located between a pair of the at least two conduits.

9. The bearing cage for a rolling element bearing assembly according to claim 1 wherein a plurality of the conduits are provided in the guide portion of the inner surface.

10. The bearing cage for a rolling element bearing assembly according to claim 1, wherein the or each guide portion is associated with a respective barrier member projecting from the inner surface towards the axis of the bore, the or each guide portion being located between the central region of the bore and its respective barrier member.

11. The bearing cage for a rolling element bearing assembly according to claim 1 wherein an angle of the taper of the bore, relative to the axis of the bore, is less than 20°

.

12. The bearing cage for a rolling element bearing assembly according to claim 1, wherein the outer surface, in a radial direction, of the bearing cage is configured to be the pilot surface of the bearing cage.

13. A bearing assembly including

an outer body and an inner body coaxially aligned with respect to a rotational axis about which the outer body and the inner body are able to rotate relative to one another,

a bearing cage including

an outer surface;

an inner surface defining a bore;

a plurality of pockets, each pocket of the plurality of pockets being configured to house a rolling element of the rolling element bearing assembly, the plurality of pockets being arranged sequentially around the bearing cage with respect to an axis of the bore;

wherein a guide portion of the inner surface is tapered in an axial direction of the bore such that dimensions of the bore increase towards a central region of the bore, the bearing cage being arranged coaxially with and radially between the inner body and the outer body, and

a respective rotatable rolling bearing element provided in each pocket of the plurality of pockets of the cage bearing to engage rotatably with the inner body and the outer body,

wherein the bearing cage further includes a plurality of conduits providing fluidic communication between the inner surface of the bearing cage and the outer surface of the bearing cage.

14. The bearing assembly according to claim 13 wherein the bearing cage includes a pilot surface for cooperating with a pilot surface of the outer body to maintain the coaxial alignment of the outer body and the bearing cage.

15. A gas turbine engine incorporating a bearing cage for a rolling element bearing assembly, the bearing cage including

an outer surface;

an inner surface defining a bore; and

a plurality of pockets, each pocket of the plurality of pockets being configured to house a rolling element of the rolling element bearing assembly, the plurality of pockets being arranged sequentially around the bearing cage with respect to an axis of the bore, wherein

a guide portion of the inner surface is tapered in an axial direction of the bore such that dimensions of the bore increase towards a central region of the bore, and

the bearing cage further includes a plurality of conduits providing fluidic communication between the inner surface of the bearing cage and the outer surface of bearing cage.