Offset thrust bearing
The invention provides an eccentric thrust bearing assembly capable of bearing axial loads in opposite directions. A first aspect of the invention relates to a thrust bearing assembly a 1 wherein a first radially outside member and a second radially inside member oppose each other at first positions a 21 separately located and clamp therebetween a rolling element a 8 disposed at each of the first positions a 21 , whereas a second radially outside member and a first radially inside member oppose each other at second positions a 22 of a different phase from that of the first positions a 21 and clamp therebetween a rolling element a 8 disposed at each of the second positions a 22 . In this bearing assembly a 1 , respective certain portions of the rolling elements are present on the same plane.
1. An eccentric thrust bearing assembly comprising: a first radially outside member and a first radially inside member positioned on a radially inner side of the first radially outside member; and a second radially outside member and a second radially inside member positioned on a radially inner side of the second radially outside member, the second radially outside and inside members disposed in opposing relation with the first radially outside and inside members,
wherein the first radially outside member opposes the second radially inside member at three or more first positions separately located along a circumferential direction thereby clamping rolling elements therebetween, the rolling elements disposed at the first positions, whereas the second radially outside member opposes the first radially inside member at three or more second positions separately located along the circumferential direction and having a different phase from that of the first positions, thereby clamping rolling elements therebetween, the rolling elements disposed at the second positions,
wherein the first radially outside member and the first radially inside member define a gap therebetween so as to be allowed to move relative to each other in the radial direction and the circumferential direction, whereas the second radially outside member and the second radially inside member define a gap therebetween so as to be allowed to move relative to each other in the radial direction and the circumferential direction,
wherein the first radially outside member and the second radially outside member are integrally interconnected, whereas the first radially inside member and the second radially inside member are integrally interconnected, and
wherein respective certain portions of the rolling elements are present on the same plane.
2. An eccentric thrust bearing assembly according to claim 1 , wherein all the rolling elements have their centers positioned on the same plane.
3. An eccentric thrust bearing assembly according to claim 1 , wherein the first radially outside member includes: outer races separately provided at the respective first positions separately located; and a first radially outside case to which all these outer races are mounted,
wherein the second radially outside member includes: outer races separately provided at the respective second positions separately located; and a second radially outside case to which all these outer races are mounted,
wherein the first radially inside member includes: inner races separately provided at the respective first positions separately located; and a first radially inside case to which all these inner races are mounted,
wherein the second radially inside member includes: inner races separately provided at the respective second positions separately located; and a second radially inside case to which all these inner races are mounted, and
wherein the rolling element is clamped between the outer race and the inner race.
4. An eccentric thrust bearing assembly according to claim 1 , wherein a relatively movable range between the radially outside member and the radially inside member, which is provided by the gap, substantially corresponds to a movable range of the rolling element.
5. An eccentric thrust bearing assembly according to claim 1 , wherein the respective groups of the first positions and the second positions are disposed at N places with equal spacing, N indicating an integer of 3 or more,
wherein the first and second radially outside cases have the same configuration, which includes: an outside ring portion defining an outer periphery of the bearing assembly; and N inward tongues projected radially inwardly from the outside ring portion as positioned at regular circumferential space intervals,
wherein the first and second radially inside cases have the same configuration, which includes: an inside ring portion defining an inner periphery of the bearing assembly; and N outward tongues projected radially outwardly from the inside ring portion as positioned at regular circumferential space intervals,
wherein all the outward tongues have the inner races mounted thereto and aligned on the same circle, whereas all the inward tongues have the outer races mounted thereto and aligned on the same circle, all the inner and outer races comprising disk-like members of the same configuration, and
wherein the first positions and the second positions are alternately located on the same circle at 360/(2N)° circumferential phase shift relative to one another.
6. An eccentric thrust bearing assembly according to claim 1 , further comprising first cage guides surrounding the respective races.
7. An eccentric thrust bearing assembly according to claim 1 , further comprising a single second cage guide for maintaining a relative positional relation among the all of the rolling elements.