ROLLING-ELEMENT BEARING

Abstract

A rolling-element bearing for a device lubricated with a fluid includes first and second bearing rings defining an interior therebetween in which rolling elements support the first ring for rotation relative to the second ring. A pumping device is located at the interior for pumping the fluid into and/or out of the interior when an element of the rolling-element bearing rotates and the rolling-element bearing is at least partially submerged in the fluid. The pumping device may be a ring having vanes that is attached to the first bearing ring or to a cage of the bearing.

Claims

1. A rolling-element bearing for a device lubricated with a fluid comprising: a first bearing ring having a first raceway and a second bearing ring having a second raceway and a rolling-element bearing interior between the first bearing ring and the second bearing ring, the first bearing ring and the second bearing ring being rotatable with respect to each other about a axis of rotation, at least one row of rolling elements in the rolling-element bearing interior, and pumping means at the rolling-element bearing interior for pumping a fluid into the rolling-element bearing interior and/or out of the rolling-element bearing interior when the first bearing ring is rotating and the rolling-element bearing is at least partially surrounded by the fluid.

2. The rolling-element bearing according to claim 1, wherein the pumping means is disposed at least partially in the rolling-element bearing interior.

3. The rolling-element bearing according to claim 1, wherein the first bearing ring is configured to rotate relative to the second bearing ring, and wherein the pumping means is attached to the first bearing ring.

4. The rolling-element bearing according to claim 1, including a bearing cage between the first bearing ring and the second bearing ring, wherein the bearing cage comprises the pumping means.

5. The rolling-element bearing according to claim 1, wherein a change of a direction of rotation of the first bearing ring or the second bearing ring changes a pumping direction of the pumping means.

6. The rolling-element bearing according to claim 1, wherein the pumping means includes at least one vane.

7. The rolling-element bearing according to claim 6, wherein the at least one vane comprises a plurality of vanes uniformly or non-uniformly distributed around the pumping means.

8. The rolling-element bearing according to claim 1, wherein the pumping means comprises a ring having a plurality of vanes extending axially and/or at an angle inclined relative to an axial direction.

9. The rolling-element bearing according to claim 8, wherein the at least one vane is airfoil shaped.

10. A method comprising: partially submerging a rolling-element bearing according to claim 9 in the fluid, and rotating the first bearing ring to pump the fluid into or out of the rolling-element bearing interior.

11. The rolling-element bearing according to claim 9, wherein the at least one vane is formed from plastic.

12. The rolling-element bearing according to claim 1, wherein the pumping means comprises a ring attached the first bearing ring and a plurality of vanes extending from the ring.

13. The rolling-element bearing according to claim 1, including a bearing cage, wherein the pumping means comprises a vane extending from the bearing cage.

14. A method comprising: partially submerging a rolling-element bearing according to claim 1 in the fluid, and rotating the first bearing ring to pump the fluid into or out of the rolling-element bearing interior.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0023] FIG. 1 is a schematic sectional view through a rolling-element bearing according to a first embodiment of the present disclosure.

[0024] FIG. 2 is a schematic sectional view through a rolling-element bearing according to a second embodiment of the present disclosure.

[0025] FIG. 3 is a schematic sectional view through a rolling-element bearing according to a third embodiment of the present disclosure.

DETAILED DESCRIPTION

[0026] In the following, identical or functionally equivalent elements are designated by the same reference numbers.

[0027] FIG. 1 shows a schematic sectional view through a rolling-element bearing 1 according to a first embodiment. The rolling-element bearing 1 is suitable in particular to be used in a fluid-lubricated device (not shown) in which the rolling-element bearing is at least partially surrounded by the fluid.

[0028] The rolling-element bearing 1 comprises a first bearing ring 2 and a second bearing ring 4, wherein the bearing rings 2, 4 include end surfaces 10, 12 that delimit the bearing rings in the axial direction. A row of rolling elements 6 is disposed between the first and second bearing rings 2, 4. The first bearing ring 2 is rotatable relative to the second bearing ring 4, wherein each of the two bearing rings 2, 4 includes a raceway (not indicated) on which the rolling elements 6 roll.

[0029] Furthermore, the rolling-element bearing 1 comprises a rolling-element bearing interior 8 in which the rolling elements are disposed and a cage 14 that is configured to hold and to space the rolling elements 6. That rolling-element bearing interior 8 is defined in the radial direction by the raceways of the bearing rings 2, 4 and in the axial direction by the end surfaces 10, 12 of the bearing rings.

[0030] In order to reduce the lubricant-caused power loss, a pumping device 18 is furthermore provided that is configured to pump a lubricant. In the rolling-element bearing 1 of FIG. 1, the pumping device is disposed on the first bearing ring 2, wherein the first bearing ring 2 is the rotating bearing ring. In particular, a change of the direction of rotation of the bearing ring 2, and thus also of the pumping device 18, can thereby change a pumping direction of the pumping device 18 so that depending on the direction of rotation, fluid can be directed into the rolling-element bearing interior 8, and/or fluid can be transported out from the rolling-element bearing interior 8.

[0031] The pumping device 18 is configured as a ring 16 that serves as a carrier element and includes a plurality of pumping elements 20 that protrude outward axially from the ring 16. In order to attach the pumping device 18 to the first bearing ring 2, the ring 16 is captively attached to the first bearing ring 2. In particular, the ring 16 can be secured in an interference-fit, friction-fit, and/or material-fit manner to the first bearing ring. Alternatively or additionally, at least one pumping element 18 can protrude axially inward from the ring 16. In particular, the at least one pumping device 18 and/or the at least one pumping element 20 can be formed from plastic, wherein, for example, the pumping elements 20 are formed integrally with the pumping device.

[0032] The plurality of pumping elements 20 are configured turbine-blade-shaped and extend in a radial direction toward the axis of rotation of the rolling-element bearing 1. Furthermore, the pumping elements 20 are employed obliquely in one direction. Alternatively the pumping elements can also have other shapes. For example, the pumping elements 20 can be configured triangular, straight, and/or sickle-shaped. Furthermore, the plurality of pumping elements 18 are uniformly distributed circumferentially around the ring 16 but can alternatively also be non-uniformly distributed.

[0033] In FIG. 1, the dimensions of the pumping device 18 are chosen such that the pumping device 18 is received in its entirety in the rolling-element bearing interior 8 so that the presence of the pumping device 18 does not increase the space requirement of the rolling-element bearing 1 in the fluid-lubricated device. Alternatively the pumping device 18 can also be disposed only partially in the rolling-element bearing interior 8 and/or be attached outside on the rotating bearing ring 2. In particular, the pumping elements 20 can protrude outward beyond the end surfaces 10, 12.

[0034] FIG. 2 shows a schematic sectional view through a rolling-element bearing 1 according to a second embodiment. The rolling-element bearing 1 of FIG. 2 differs from the rolling-element bearing 1 of FIG. 1 in that the pumping device 18 is attached to the cage 14. In particular, the pumping device 18 and the cage 14 can be formed integrally. This makes possible a particularly space-saving arrangement of the pumping device 18 in the rolling-element bearing interior 8.

[0035] FIG. 3 shows a schematic sectional view through a rolling-element bearing 1 according to a third embodiment. The rolling-element bearing 1 of FIG. 3 differs from the rolling-element bearing 1 of FIG. 1 in that the pumping element is an airfoil-shaped vane 20′ that extends from the ring 16 attached to the bearing ring 2.

[0036] In summary, in the rolling-element bearing 1 the lubricant-caused power loss can be reduced by the pumping device 18. The pumping device is configured to pump the fluid into the rolling-element bearing interior 8 and/or out of the rolling-element bearing interior 8, and is attached to a rotating element of the rolling-element bearing 1. The pumping device 18 is advantageously received at least partially in the rolling-element bearing interior 8. This makes it possible to not excessively increase the space requirement of the rolling-element bearing 1, with the result that the described rolling-element bearing 1 can also be used in tight installation situations.

[0037] Due to the chosen shape and/or position of the pumping element 20 and/or the rotational speed and/or the direction of rotation of the rolling-element bearing 1 the desired direction in which the fluid is pumped and the amount of fluid that is pumped by the device can advantageously be set so that churning losses can be further reduced.

REFERENCE NUMBER LIST

[0038] 1 Rolling-element bearing [0039] 2, 4 Bearing ring [0040] 6 Rolling element [0041] 8 Rolling-element bearing interior [0042] 10, 12 End surface [0043] 14 Cage [0044] 16 Ring [0045] 18 Pumping device [0046] 20 Pumping element