Foil bearing and method for manufacturing thereof

Patent metadata

Field	Value
Publication number	US-2016356310-A1
Application number	US-201415103002-A
Country	US
Kind code	A1
Filing date	Nov 19, 2014
Priority date	Dec 12, 2013
Publication date	Dec 8, 2016
Grant date	—

Abstract

A foil bearing (thrust foil bearing ( 40 )) includes a foil holder ( 41 ) and a plurality of foils ( 42 ) arrayed in a circumferential direction. Each of the foils ( 42 ) includes a body portion ( 42 a ) having a thrust bearing surface (S 2 ) and an extended portion ( 42 b ) extending from the body portion ( 42 a ) to a radially outer side. An end portion ( 42 d ) of the body portion ( 42 a ) of each of the foils ( 42 ) on one circumferential side is arranged so as to be overlapped on the body portion ( 42 a ) of adjacent one of the foils ( 42 ). The extended portions ( 42 b ) of the plurality of foils ( 42 ) are fixed onto the same plane of the foil holder ( 41 ).

First claim

1 . The foil bearing, comprising:
a foil holder; and a plurality of foils mounted to the foil holder so as to be arrayed in a circumferential direction of the foil holder, the foil bearing being configured to support a shaft in thrust directions of the shaft, the shaft being rotatable relatively to one side in the circumferential direction, each of the plurality of foils comprising:
a body portion having a thrust bearing surface; and
an extended portion extending from the body portion to a radially outer side,
an end portion of the body portion of the each of the plurality of foils on one circumferential side being arranged so as to be overlapped on the body portion of adjacent one of the plurality of foils, the extended portions of the plurality of foils being fixed onto the same plane of the foil holder.

2 . The foil bearing according to claim 1 , wherein the extended portion extends from the body portion to the radially outer side in a direction inclined to another circumferential side.

3 . The foil bearing according to claim 1 ,
wherein the foil holder axially faces a thrust collar provided on the shaft, wherein a region including the end portion of the each of the plurality of foils on the one circumferential side forms a top foil portion having the thrust bearing surface, wherein a region including an end portion of the each of the plurality of foils on another circumferential side forms a back foil portion configured to support the top foil portion of the adjacent one of the plurality of foils from behind, wherein the foil bearing has a thrust bearing gap formed between the thrust bearing surface and an end surface of the thrust collar along with the relative rotation of the shaft, wherein the thrust bearing gap has a small gap portion formed between a region of the top foil portion of the each of the plurality of foils, which includes an end portion of the top foil portion on the one circumferential side, and the end surface of the thrust collar, wherein the thrust bearing gap has a large gap portion formed between a region of the top foil portion of the each of the plurality of foils, which includes an end portion of the top foil portion on the another circumferential side, and the end surface of the thrust collar, and wherein the foil bearing has a communication path configured to bring the large gap portion and a space between the each of the plurality of foils and the foil holder into communication with each other.

4 . The foil bearing according to claim 3 ,
wherein the each of the plurality of foils has a cutout formed therein, and wherein the cutout forms the communication path.

5 . The foil bearing according to claim 1 ,
wherein a region including the end portion of the each of plurality of the foils on the one circumferential side forms a top foil portion having the thrust bearing surface, wherein a region including an end portion of the each of the plurality of foils on another circumferential side forms a back foil portion configured to support the top foil portion of the adjacent one of the plurality of foils from behind, wherein the end portion of the each of the plurality of foils on the another circumferential side comprises a pair of inclined portions extending from both radial end sides toward a radial center so as to be inclined to the one circumferential side, and wherein the back foil portion of the each of the plurality of foils comprises a fragile portion formed in a radially intermediate portion thereof and having lower strength to a compressive stress than regions on both radial sides of the fragile portion.

6 . The foil bearing according to claim 5 , wherein the fragile portion is formed by forming a slit extending in the circumferential direction in the back foil portion.

7 . A foil bearing, comprising:
a foil holder; and a plurality of foils mounted to an inner peripheral surface of the foil holder so as to be arrayed in a circumferential direction of the foil holder, the foil bearing being configured to support a shaft in a radial direction of the shaft, the shaft being rotatable relatively to one side in the circumferential direction, each of the plurality of foils comprising:
a body portion having a radial bearing surface; and
an extended portion extending from the body portion to one axial side,
an end portion of the body portion of the each of the plurality of foils on one circumferential side being arranged so as to be overlapped on the body portion of adjacent one of the plurality of foils, the extended portions of the plurality of foils being fixed onto the same cylindrical surface of the foil holder.

8 . The foil bearing according to claim 7 , wherein the extended portion extends from the body portion to the one axial side in a direction inclined to another circumferential side.

9 . The foil bearing according to claim 7 ,
wherein a region including the end portion of the each of the plurality of foils on the one circumferential side forms a top foil portion having the radial bearing surface, wherein a region including an end portion of the each of the plurality of foils on another circumferential side forms a back foil portion configured to support the top foil portion of the adjacent one of the plurality of foils from behind, wherein the foil bearing has a radial bearing gap formed between the radial bearing surface and an outer peripheral surface of the shaft along with the relative rotation of the shaft, wherein the radial bearing gap has a small gap portion formed between a region of the top foil portion of the each of the plurality of foils, which includes an end portion of the top foil portion on the one circumferential side, and the outer peripheral surface of the shaft, wherein the radial bearing gap has a large gap portion formed between a region of the top foil portion of the each of the plurality of foils, which includes an end portion of the top foil portion on the another circumferential side, and the outer peripheral surface of the shaft, and wherein the foil bearing has a communication path configured to bring the large gap portion and a space between the each of the plurality of foils and the foil holder into communication with each other.

10 . The foil bearing according to claim 9 ,
wherein the each of the plurality of foils has a cutout formed therein, and wherein the cutout forms the communication path.

11 . The foil bearing according to claim 7 ,
wherein a region including the end portion of the each of the plurality of foils on the one circumferential side forms a top foil portion having the radial bearing surface, wherein a region including an end portion of the each of the plurality of foils on another circumferential side forms a back foil portion configured to support the top foil portion of the adjacent one of the plurality of foils from behind, wherein the end portion of the each of the plurality of foils on the another circumferential side comprises a pair of inclined portions extending from both axial end sides toward an axial center so as to be inclined to the one circumferential side, and wherein the back foil portion of the each of the plurality of foils comprises a fragile portion formed in an axially intermediate portion thereof and having lower strength to a compressive stress than regions on both axial sides of the fragile portion.

12 . The foil bearing according to claim 11 , wherein the fragile portion is formed by forming a slit extending in the circumferential direction in the back foil portion.

13 . A method of manufacturing a foil bearing configured to support a shaft in thrust directions of the shaft, the

Assignees

• Ntn Toyo Bearing Co Ltd

Inventors

• Yoshino Masato
• Fujiwara Hiroki

Classifications

• F16C43/02

  Assembling sliding-contact bearings · CPC title

• F16C17/10

  for both radial and axial load · CPC title

• F16C2360/23

  Gas turbine engines · CPC title

• F16C17/042

  with flexible leaves to create hydrodynamic wedge, e.g. axial foil bearings · CPC title

• F16C2360/24

  Turbochargers · CPC title