US-12624724-B2 - Thrust bearing

US12624724B2US 12624724 B2US12624724 B2US 12624724B2US-12624724-B2

Abstract

A thrust bearing includes an upper foil portion including a bearing surface that faces a rotary member rotatable about a rotation axis, and a lower foil portion that elastically supports the upper foil portion. The upper foil portion is divided into a plurality of portions.

Inventors

Takahiro Minami
Hidefumi Nakao
Takato HATANO
Katsuhisa Takahashi

Assignees

TOYOTA JIDOSHA KABUSHIKI KAISHA

Dates

Publication Date: 20260512
Application Date: 20241202
Priority Date: 20231207

Claims (9)

1 . A thrust bearing comprising: an upper foil portion including a bearing surface that faces a rotary member rotatable about a rotation axis; and a lower foil portion that elastically supports the upper foil portion, wherein the upper foil portion is divided into a plurality of portions, wherein the lower foil portion includes an underlay foil portion including a first plate-shaped member that planarly supports part of the bearing surface of the upper foil portion; wherein the lower foil portion includes a first support foil portion disposed below the underlay foil portion and including a plurality of first support members, a pad foil portion disposed below the first support foil portion and including a second plate-shaped member corresponding to the first plate-shaped member, and a second support foil portion disposed below the pad foil portion and including a plurality of second support members; wherein the first plate-shaped member is supported by two first support members out of the plurality of first support members; wherein one first support member out of the two first support members is supported by one part of the second plate-shaped member and two second support members out of the plurality of second support members; and wherein the other first support member out of the two first support members is supported by a different part from the one part of the second plate-shaped member, one second support member out of the two second support members, and a different second support member from the two second support members.
2 . The thrust bearing according to claim 1 , wherein the lower foil portion elastically supports the upper foil portion to cause a support stiffness of each of the plurality of portions on an upstream side in a rotation direction of the rotary member to be smaller than a support stiffness of each of the plurality of portions on a downstream side in the rotation direction.
3 . The thrust bearing according to claim 2 , wherein: the one first support member out of the two first support members is, in the rotation direction, disposed on the upstream side of the other first support member out of the two first support members; and a distance between the two second support members is larger than a distance between the one second support member out of the two second support members and the different second support member from the two second support members.
4 . The thrust bearing according to claim 2 , wherein a thickness of the first plate-shaped member on the upstream side in the rotation direction is smaller than a thickness of the first plate-shaped member on the downstream side in the rotation direction.
5 . The thrust bearing according to claim 2 , wherein: the one first support member out of the two first support members is, in the rotation direction, disposed on the upstream side of the other first support member out of the two first support members; and a thickness of the one first support member out of the two first support members is smaller than a thickness of the other first support member out of the two first support members.
6 . The thrust bearing according to claim 2 , wherein: the one part of the second plate-shaped member and the two second support members define a double-end supported beam structure that supports the one first support member out of the two first support members; and the different part from the one part of the second plate-shaped member, the one second support member out of the two second support members, and the different second support member from the two second support members define a double-end supported beam structure that supports the other first support member out of the two first support members.
7 . The thrust bearing according to claim 1 , wherein: the first plate-shaped member of the underlay foil portion is disposed in an area surrounded by a first annular member; the underlay foil portion further includes the first annular member extending in a circumferential direction of the thrust bearing, and a first connection member connecting the first annular member and the first plate-shaped member; a length along a shape of the first connection member from a first connection point to a second connection point is larger than a length of a straight line connecting the first connection point and the second connection point; the first connection point is a connection point between the first annular member and the first connection member; and the second connection point is a connection point between the first plate-shaped member and the first connection member.
8 . The thrust bearing according to claim 1 , wherein: the first support foil portion includes a second annular member extending in a circumferential direction of the thrust bearing, the first support members disposed in an area surrounded by the second annular member, and a second connection member connecting the second annular member and the one first support member out of the plurality of first support members; a length along a shape of the second connection member from a third connection point to a fourth connection point is larger than a length of a straight line connecting the third connection point and the fourth connection point; the third connection point is a connection point between the second annular member and the second connection member; and the fourth connection point is a connection point between the one first support member and the second connection member.
9 . A thrust bearing comprising: an upper foil portion including a bearing surface that faces a rotary member rotatable about a rotation axis; and a lower foil portion that elastically supports the upper foil portion, wherein the upper foil portion is divided into a plurality of portions; wherein the lower foil portion includes an underlay foil portion including a first plate-shaped member that planarly supports part of the bearing surface of the upper foil portion; wherein the first plate-shaped member of the underlay foil portion is disposed in an area surrounded by a first annular member; wherein the underlay foil portion further includes: the first annular member extending in a circumferential direction of the thrust bearing, and a first connection member connecting the first annular member and the first plate-shaped member; wherein a length along a shape of the first connection member from a first connection point to a second connection point is larger than a length of a straight line connecting the first connection point and the second connection point; wherein the first connection point is a connection point between the first annular member and the first connection member; and wherein the second connection point is a connection point between the first plate-shaped member and the first connection member.

Description

CROSS-REFERENCE TO RELATED APPLICATION This application claims priority to Japanese Patent Application No. 2023-206955 filed on Dec. 7, 2023, incorporated herein by reference in its entirety. BACKGROUND 1. Technical Field The present disclosure relates to a thrust bearing, and more particularly, to a technical field of a foil laminated fluid thrust bearing. 2. Description of Related Art For example, U.S. Pat. No. 6,702,463 discloses a foil laminated fluid thrust bearing. U.S. Pat. No. 9,062,712 is another related art document related to the present disclosure. SUMMARY The thrust bearing is disposed between a rotary member and a stationary member. The thrust bearing includes a top foil portion having a bearing surface that faces the rotary member. The thrust bearing bears a thrust in a direction in which the rotation shaft of the rotary member presses the bearing in a non-contact manner via a fluid film (e.g., air) between the rotary member and the top foil portion. When the relative speed between the thrust bearing and the rotary member is relatively high, the load capacity of the thrust bearing may decrease due to an increase in temperature of the fluid film caused by viscous heat generation. In the thrust bearing described in U.S. Pat. No. 6,702,463, the top foil portion is formed from a single member. Therefore, in the thrust bearing described in U.S. Pat. No. 6,702,463, the temperature of the fluid film is likely to increase and the load capacity of the thrust bearing is likely to decrease. The present disclosure provides a thrust bearing in which a decrease in the load capacity of the thrust bearing can be suppressed. A aspect of the present disclosure relates to a thrust bearing. The thrust bearing includes an upper foil portion including a bearing surface that faces a rotary member rotatable about a rotation axis, and a lower foil portion that elastically supports the upper foil portion. The upper foil portion is divided into a plurality of portions. In the thrust bearing according to the aspect of the present disclosure, the lower foil portion may include an underlay foil portion including a first plate-shaped member that planarly supports part of the bearing surface of the upper foil portion. In the thrust bearing according to the aspect of the present disclosure, the lower foil portion may include a first support foil portion disposed below the underlay foil portion and including a plurality of first support members, a pad foil portion disposed below the first support foil portion and including a second plate-shaped member corresponding to the first plate-shaped member, and a second support foil portion disposed below the pad foil portion and including a plurality of second support members. The first plate-shaped member may be supported by two first support members out of the plurality of first support members. One first support member out of the two first support members may be supported by one part of the second plate-shaped member and two second support members out of the plurality of second support members. The other first support member out of the two first support members may be supported by a different part from the one part of the second plate-shaped member, one second support member out of the two second support members, and a different second support member from the two second support members. In the thrust bearing according to the aspect of the present disclosure, the lower foil portion may elastically support the upper foil portion to cause a support stiffness of each of the plurality of portions on an upstream side in a rotation direction of the rotary member to be smaller than a support stiffness of each of the plurality of portions on a downstream side in the rotation direction. In the thrust bearing according to the aspect of the present disclosure, the one first support member out of the two first support members may, in the rotation direction, be disposed on the upstream side of the other first support member out of the two first support members. A distance between the two second support members may be larger than a distance between the one second support member out of the two second support members and the different second support member from the two second support members. In the thrust bearing according to the aspect of the present disclosure, a thickness of the first plate-shaped member on the upstream side in the rotation direction may be smaller than a thickness of the first plate-shaped member on the downstream side in the rotation direction. In the thrust bearing according to the aspect of the present disclosure, the one first support member out of the two first support members may, in the rotation direction, be disposed on the upstream side of the other first support member out of the two first support members. A thickness of the one first support member out of the two first support members may be smaller than a thickness of the other first support member out of the two