Foil bearing

Abstract

To support a rotational shaft stably.SOLUTION: A first insertion plate part 32 is provided with a wear inhibiting member 60 that faces a removal preventing member 50 in an axial direction A and inhibits wear between itself and the removal preventing member 50. Consequently, the wear inhibiting member 60 inhibits wear between the first insertion plate part 32 and the removal preventing member 50. As a result, the position of a top foil 30 relative to a bearing housing 20 is inhibited from shifting in the axial direction A of the bearing housing 20.SELECTED DRAWING: Figure 6

Description

[Technical field]

[0001] The present invention relates to a foil bearing. [Background technology]

[0002] The foil bearing has a bearing housing, a top foil, and a bump foil. The bearing housing is cylindrical. A rotating shaft is inserted into the bearing housing. The top foil is thin plate-shaped. The top foil is disposed between the rotating shaft and the bearing housing. The bump foil is thin plate-shaped. The bump foil elastically supports the top foil between the bearing housing and the top foil.

[0003] For example, as in Patent Document 1, a groove may be formed on the inner peripheral surface of the bearing housing. The groove opens to an axial end of the bearing housing. At least one end of the top foil is formed with a first insertion plate portion that is bent toward the groove and inserted into the groove. At least one end of the bump foil is formed with a second insertion plate portion that is bent toward the groove and inserted into the groove.

[0004] The foil bearing has a pair of anti-slip portions. Each of the anti-slip portions overlaps with the first insertion plate portion and the second insertion plate portion in the axial direction of the bearing housing and covers the groove. The top foil and the bump foil may move in the axial direction of the bearing housing. At this time, the first insertion plate portion of the top foil and the second insertion plate portion of the bump foil come into contact with each of the anti-slip portions, thereby preventing the top foil and the bump foil from coming out of the bearing housing. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent Publication No. 2022-57207 Summary of the Invention [Problem to be solved by the invention]

[0006] However, when at least one of the first and second insertion plate parts comes into contact with the retaining portion, there is a risk that at least one of the first and second insertion plate parts and the retaining portion will wear out. When at least one of the first and second insertion plate parts and the retaining portion wear out, the position of at least one of the top foil and bump foil relative to the bearing housing will shift in the axial direction of the bearing housing. When the position of at least one of the top foil and bump foil relative to the bearing housing shifts in the axial direction of the bearing housing, there is a risk that the rotating shaft will no longer be stably supported. [Means for solving the problem]

[0007] A foil bearing that solves the above-mentioned problem comprises a cylindrical bearing housing through which a rotating shaft is inserted, a thin-plate-shaped top foil arranged between the rotating shaft and the bearing housing, and a thin-plate-shaped bump foil that elastically supports the top foil between the bearing housing and the top foil, wherein a groove is formed on the inner surface of the bearing housing and opens to an axial end of the bearing housing, at least one end of the top foil is formed with a first insertion plate portion that is bent toward the groove and inserted into the groove, and at least one end of the bump foil is formed with a second insertion plate portion that is bent toward the groove and inserted into the groove, and the foil bearing has a pair of anti-pullout portions that overlap the first insertion plate portion and the second insertion plate portion in the axial direction and cover the groove, and at least one of the first insertion plate portion and the second insertion plate portion is provided with a wear-inhibiting member that faces the anti-pullout portion in the axial direction and inhibits wear between the anti-pullout portion and the first insertion plate portion.

[0008] According to this, the wear suppressing member suppresses wear between at least one of the first and second insertion plate portions and the retaining portion. Therefore, it is possible to suppress the position of at least one of the top foil and the bump foil relative to the bearing housing from shifting in the axial direction of the bearing housing. As a result, it is possible to stably support the rotating shaft.

[0009] In the above foil bearing, both the first insertion plate portion and the second insertion plate portion are inserted into the groove, and the wear reduction member is arranged between the first insertion plate portion and the second insertion plate portion so as to be able to come into contact with the anti-pullout portion.

[0010] According to this, the wear-reduction member comes into contact with the anti-slip portion between the first insertion plate portion and the second insertion plate portion, thereby reducing wear between the anti-slip portion and at least one of the first insertion plate portion and the second insertion plate portion.

[0011] In the above foil bearing, the wear-reducing member may extend from between the first insertion plate portion and the second insertion plate portion to between the first insertion plate portion and the groove, and may be arranged so as to be able to come into contact with the anti-slip portion.

[0012] According to this, the wear-reduction member extends from between the first insertion plate portion and the second insertion plate portion to between the first insertion plate portion and the groove, and comes into contact with the anti-slip portion, thereby reducing wear between the anti-slip portion and at least one of the first insertion plate portion and the second insertion plate portion.

[0013] In the above foil bearing, the wear-reducing member may be provided in the first insertion plate portion, and the second insertion plate portion may be provided with an opposing portion that is bent so as to face the anti-pullout portion in the axial direction.

[0014] According to this, when the bump foil moves in the axial direction of the bearing housing and the opposing portion comes into contact with the anti-slip portion, a spring action is generated in the opposing portion, absorbing the load acting on the anti-slip portion. Therefore, wear of the second insertion plate portion and the anti-slip portion can be suppressed. Meanwhile, wear between the first insertion plate portion and the anti-slip portion is suppressed by the wear suppression member. As a result, wear between the first insertion plate portion and the anti-slip portion and between the first insertion plate portion and the second insertion plate portion and the anti-slip portion can be suppressed.

[0015] In the above foil bearing, the hardness of the wear-suppressing member may be lower than the hardness of the first insertion plate portion, thereby making it possible to suppress wear of the retaining portion when the wear-suppressing member comes into contact with the retaining portion.

[0016] In the above foil bearing, a first coating layer may be formed on an outer circumferential surface of the wear-inhibiting member, which can further prevent the retaining portion from wearing down when the wear-inhibiting member comes into contact with the retaining portion.

[0017] In the above foil bearing, a second coating layer is formed on the bearing surface of the top foil and the outer peripheral surface of the first insertion plate portion, and the second coating layer formed on the outer peripheral surface of the first insertion plate portion is preferably covered with the wear-suppressing member.

[0018] According to this, while the wear of the bearing surface of the top foil is suppressed by the second coating layer, the wear between the first insertion plate portion and the wear-suppressing member can also be suppressed by the second coating layer.

[0019] In the above foil bearing, the hardness of the first coating layer may be lower than the hardness of the second coating layer. This makes it possible to prevent wear powder generated by the wear of the first coating layer from promoting wear of the second coating layer, thereby avoiding a problem in which the bearing surface of the top foil is worn due to wear of the second coating layer. Effect of the Invention

[0020] According to this invention, the rotating shaft can be stably supported. [Brief description of the drawings]

[0021] [Figure 1] FIG. 1 is a schematic configuration diagram showing a centrifugal compressor according to an embodiment. [Diagram 2] FIG. 2 is a front view showing a foil bearing. [Diagram 3] FIG. 3 is an exploded perspective view of a foil bearing. [Figure 4] FIG. 4 is an enlarged cross-sectional perspective view showing a portion of the foil bearing. [Diagram 5] FIG. 5 is an enlarged front view showing a portion of the foil bearing. [Figure 6] FIG. 6 is a cross-sectional view taken along line 6-6 in FIG. [Figure 7] FIG. 7 is a cross-sectional view of a foil bearing in a modified example. [Figure 8] FIG. 8 is a cross-sectional view of a foil bearing in a modified example. [Figure 9] FIG. 9 is a cross-sectional view of a foil bearing in a modified example. [Figure 10] FIG. 10 is a cross-sectional view taken along line 10-10 in FIG. [Figure 11] FIG. 11 is a cross-sectional view of a foil bearing in a modified example. [Figure 12] FIG. 12 is a cross-sectional view of a foil bearing in a modified example. [Figure 13] FIG. 13 is a cross-sectional view of a foil bearing in a modified example. [Figure 14]FIG. 14 is a cross-sectional view of a foil bearing in a modified example. [Figure 15] FIG. 15 is a cross-sectional view of a foil bearing in a modified example. [Figure 16] FIG. 16 is a cross-sectional view of a foil bearing in a modified example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0022] An embodiment of a foil bearing will be described below with reference to Figs. 1 to 6. The foil bearing of this embodiment is mounted on a centrifugal compressor. The centrifugal compressor is mounted on a fuel cell vehicle. The centrifugal compressor compresses air as a fluid to be supplied to a fuel cell stack.

[0023] <Schematic configuration of centrifugal compressor> As shown in FIG. 1, the centrifugal compressor 100 includes two foil bearings 10, a housing 101, a motor 102, a rotating shaft 103, and an impeller 104. The motor 102, the rotating shaft 103, and the impeller 104 are accommodated in the housing 101. A motor chamber 101a and an impeller chamber 101b are formed in the housing 101. The motor 102 is accommodated in the motor chamber 101a. The impeller 104 is accommodated in the impeller chamber 101b. The rotating shaft 103 extends from the motor chamber 101a to the impeller chamber 101b. The motor 102 is attached to the rotating shaft 103. The impeller 104 is attached to an end of the rotating shaft 103. The rotating shaft 103 rotates when the motor 102 is driven. The impeller 104 rotates integrally with the rotating shaft 103 as the rotating shaft 103 rotates. As the impeller 104 rotates, air is drawn into the impeller chamber 101b from outside the housing 101, and the air drawn into the impeller chamber 101b is compressed by the rotation of the impeller 104. The air compressed by the rotation of the impeller 104 is discharged to the outside of the housing 101.

[0024] <Foil bearings> The two foil bearings 10 support the rotating shaft 103 in a radial direction Rd. The radial direction Rd is the radial direction of the rotating shaft 103. The two foil bearings 10 are provided at positions sandwiching the motor 102 in the axial direction of the rotating shaft 103. The two foil bearings 10 are fixed to a housing 101.

[0025] 2 and 3, the foil bearing 10 includes a cylindrical bearing housing 20, a thin plate-like top foil 30, and three thin plate-like bump foils 40. The foil bearing 10 also includes a pair of retaining members 50 as a pair of retaining portions. The bearing housing 20 is made of aluminum, for example.

[0026] <Bearing housing> 2, a rotating shaft 103 is inserted through the bearing housing 20. In the following description, the axial direction of the bearing housing 20 may be simply referred to as the "axial direction A", the circumferential direction of the bearing housing 20 may be simply referred to as the "circumferential direction B", and the radial direction of the bearing housing 20 may be simply referred to as the "radial direction C".

[0027] As shown in Fig. 3, the inner peripheral surface 20a of the bearing housing 20 is a cylindrical surface curved in the circumferential direction B. The bearing housing 20 has a first end 21 and a second end 22. The first end 21 and the second end 22 are ends of the bearing housing 20 in the axial direction A. The first end 21 is an end of the bearing housing 20 located on one side in the axial direction A. The second end 22 is an end of the bearing housing 20 located on the other side in the axial direction A.

[0028] Grooves 20b are formed on the inner peripheral surface 20a of the bearing housing 20. Three grooves 20b are provided on the inner peripheral surface 20a of the bearing housing 20. The three grooves 20b are arranged at a predetermined interval in the circumferential direction B. The grooves 20b extend in the axial direction A. Each groove 20b is provided over the entire length of the inner peripheral surface 20a of the bearing housing 20 in the axial direction A. A first end of each groove 20b in the axial direction A opens to an end portion of the bearing housing 20 located on one side in the axial direction A. A second end of each groove 20b in the axial direction A opens to an end portion of the bearing housing 20 located on the other side in the axial direction A. Thus, the grooves 20b open to an end portion of the bearing housing 20 in the axial direction A.

[0029] An annular notched groove 20c is formed in each of the first end 21 and the second end 22. Both notched grooves 20c are open to the outer circumferential surface of the bearing housing 20. One of both notched grooves 20c is open to a first end surface of the bearing housing 20. The other of both notched grooves 20c is open to a second end surface of the bearing housing 20. The notched groove 20c has a cylindrical surface 20d extending in the axial direction A and an annular surface 20e extending in the radial direction C. Each groove 20b is open to the cylindrical surface 20d and the annular surface 20e.

[0030] <Top foil> 2, the top foil 30 is disposed inside the bearing housing 20. The top foil 30 is disposed between the rotating shaft 103 and the bearing housing 20.

[0031] As shown in FIG. 3, the top foil 30 is formed by bending a long, flexible metal plate into a cylindrical shape. The top foil 30 is substantially cylindrical. The axial direction of the top foil 30 coincides with the axial direction A of the bearing housing 20. The circumferential direction of the top foil 30 coincides with the circumferential direction B of the bearing housing 20. The radial direction of the top foil 30 coincides with the radial direction C of the bearing housing 20. The length of the axial direction A of the top foil 30 is the same as the length of the axial direction A of the bearing housing 20. The top foil 30 is formed of, for example, stainless steel or an Inconel (registered trademark) type nickel alloy.

[0032] The top foil 30 has a bent portion 31. The bent portion 31 is formed by bending an end portion located on one side of the circumferential direction of the top foil 30 radially outward of the top foil 30. The end portion located on the other side of the circumferential direction of the top foil 30 is a free end portion. The inner circumferential surface of the portion of the top foil 30 other than the bent portion 31 that is formed into a substantially cylindrical shape is a bearing surface 30a. The bearing surface 30a is a surface that supports the rotating shaft 103.

[0033] The bent portion 31 has a pair of notches 31a. Each notch 31a is provided at both end edges of the bent portion 31 in the axial direction A. Each notch 31a is formed by cutting out a part of the end edge of the bent portion 31 in the axial direction A. Each notch 31a has a first notch edge 311a and a second notch edge 312a.

[0034] As shown in FIG. 4, the first cutout edge 311a extends in the radial direction C. The first cutout edge 311a is continuous with the long edge 311 of the bent portion 31. The first cutout edge 311a is continuous with the second cutout edge 312a. The second cutout edge 312a extends in the axial direction A. The second cutout edge 312a is continuous with the short edge 312 of the bent portion 31. The long edge 311 and the short edge 312 of the bent portion 31 are connected via the first cutout edge 311a and the second cutout edge 312a.

[0035] The bent portion 31 of the top foil 30 is inserted into one of the grooves 20b. Specifically, the portion of the bent portion 31, in which the first notch edge 311a of each notch 31a is at both ends in the axial direction A, is inserted into the groove 20b. Therefore, the portion of the bent portion 31, in which the first notch edge 311a of each notch 31a is at both ends in the axial direction A, forms a first insertion plate portion 32 to be inserted into the groove 20b. Therefore, the top foil 30 has the first insertion plate portion 32 that is inserted into the groove 20b and extends in the axial direction A. In this way, the first insertion plate portion 32 that is bent toward the groove 20b and inserted into the groove 20b is formed at one end of the top foil 30.

[0036] <Bump foil> 2, the three bump foils 40 are disposed between the bearing housing 20 and the top foil 30. The three bump foils 40 are disposed at predetermined intervals in the circumferential direction B. The plate thickness of the bump foils 40 is thinner than the plate thickness of the top foil 30.

[0037] As shown in Fig. 3, each bump foil 40 is formed by bending a long, flexible metal plate material into a substantially arc shape in the circumferential direction B. The short side direction of each bump foil 40 coincides with the axial direction A of the bearing housing 20. The length of each bump foil 40 in the short side direction is shorter than the length of the bearing housing 20 in the axial direction A. The length of each bump foil 40 in the short side direction is shorter than the length of the top foil 30 in the axial direction A. Each bump foil 40 is formed, for example, from stainless steel or an Inconel-type nickel alloy.

[0038] As shown in FIG. 2, each bump foil 40 has a plurality of valleys 43 and a plurality of peaks 44. Each valley 43 is in contact with the inner peripheral surface 20a of the bearing housing 20. Each valley 43 extends along the inner peripheral surface 20a of the bearing housing 20. Each peak 44 is in contact with the outer peripheral surface of the top foil 30. Each peak 44 protrudes in a direction away from the inner peripheral surface 20a of the bearing housing 20. Each peak 44 is curved in an arc shape so as to bulge toward the outer peripheral surface of the top foil 30. Each bump foil 40 has a wave shape in which a plurality of valleys 43 and peaks 44 are alternately arranged in the circumferential direction B. Both ends of each bump foil 40 in the circumferential direction B are valleys 43.

[0039] 4 and 5, each bump foil 40 has a second insertion plate portion 41. The second insertion plate portion 41 is formed by bending a portion of one of the valley portions 43 located at both ends of the bump foil 40 in the circumferential direction B toward the opposite side to the peak portion 44. The other ends of the valley portions 43 located at both ends of the bump foil 40 in the circumferential direction B are free ends.

[0040] As shown in Fig. 6, the second insertion plate portion 41 of the bump foil 40 is provided with an opposing portion 42. The opposing portions 42 are provided on both ends of the second insertion plate portion 41 of the bump foil 40 in the axial direction A. Each opposing portion 42 extends in the same direction in the circumferential direction B from the respective ends of the second insertion plate portion 41 in the axial direction A. The angle θ1 between the opposing portion 42 and the second insertion plate portion 41 is an obtuse angle.

[0041] The second insertion plate portion 41 and the opposing portion 42 of each bump foil 40 are inserted into each groove 20b. The bump foil 40 has the second insertion plate portion 41 that is inserted into the groove 20b and extends in the axial direction A. Thus, one end of each bump foil 40 is formed with the second insertion plate portion 41 that is bent toward the groove 20b and inserted into the groove 20b.

[0042] 2, one of the second insertion plate portions 41 of the three bump foils 40 is inserted into one groove 20b together with the first insertion plate portion 32 of the top foil 30. Therefore, both the first insertion plate portion 32 and the second insertion plate portion 41 are inserted into one groove 20b. The first insertion plate portion 32 of the top foil 30 and the second insertion plate portion 41 of the bump foil 40 are inserted into the groove 20b with the thickness direction of the first insertion plate portion 32 of the top foil 30 and the thickness direction of the second insertion plate portion 41 of the bump foil 40 coinciding with each other.

[0043] The second insertion plate portions 41 of the remaining two bump foils 40 are inserted into the remaining two grooves 20b, respectively. The three bump foils 40 are disposed outwardly of the top foil 30 in the radial direction C. The three bump foils 40 elastically support the top foil 30 between the bearing housing 20 and the top foil 30.

[0044] <Preventive material> 3, each of the retaining members 50 is annular. Each of the retaining members 50 is made of, for example, stainless steel. The hardness of each of the retaining members 50 is lower than the hardness of the top foil 30 and the bump foil 40.

[0045] The inner diameter of the retaining members 50 is the same as the outer diameter of the cylindrical surface 20d of the bearing housing 20. One of the pair of retaining members 50 is fitted into the notched groove 20c formed in the first end 21 of the bearing housing 20. The other of the pair of retaining members 50 is fitted into the notched groove 20c formed in the second end 22 of the bearing housing 20. The pair of retaining members 50 abut against the annular surface 20e. The pair of retaining members 50 face the portion of the groove 20b that opens into the annular surface 20e in the axial direction A. The pair of retaining members 50 cover the groove 20b. The pair of retaining members 50 are fixed to the bearing housing 20 by a fixing means (not shown).

[0046] 3 and 5, the retaining member 50 overlaps the first insertion plate portion 32 and the second insertion plate portion 41 of each bump foil 40 in the axial direction A. The retaining member 50 faces the first insertion plate portion 32 and a part of the facing portion 42 of the top foil 30 in the axial direction A. Therefore, the second insertion plate portion 41 is provided with the facing portion 42 that is bent so as to face the retaining member 50 in the axial direction A. The pair of retaining members 50 face the top foil 30 and the bump foil 40 in the axial direction A and prevent the top foil 30 and the bump foil 40 from coming off the bearing housing 20.

[0047] 6, each of the anti-slip members 50 has an opposing surface 50a at a position facing the first insertion plate portion 32 in the axial direction A and overlapping the second insertion plate portion 41 in the axial direction A. The opposing surface 50a is a surface extending in the radial direction C. The opposing surface 50a extends in a direction perpendicular to the axis of the bearing housing 20. In the axial direction A, a distance L1 between the two opposing surfaces 50a is longer than a length L2 in the axial direction A between end portions of each of the two opposing portions 42 on the side opposite to the second insertion plate portion 41.

[0048] <Wear-suppressing part> The wear-inhibiting member 60 is provided in the first insertion plate portion 32 of the top foil 30. Therefore, the wear-inhibiting member 60 is provided in the first insertion plate portion 32 of the top foil 30. The wear-inhibiting member 60 is in the form of a thin plate extending in the axial direction A. The wear-inhibiting member 60 is in the form of a flat plate. The wear-inhibiting member 60 is made of resin. The hardness of the wear-inhibiting member 60 is lower than the hardness of the first insertion plate portion 32 of the top foil 30. The hardness of the wear-inhibiting member 60 is lower than the hardness of the retaining member 50.

[0049] The wear-inhibiting member 60 is provided on a surface of the first insertion plate portion 32 of the top foil 30 that faces the second insertion plate portion 41 of the bump foil 40. The wear-inhibiting member 60 is provided on a surface of the first insertion plate portion 32 of the top foil 30 that is located on one side in the thickness direction. The wear-inhibiting member 60 is provided on the first insertion plate portion 32 with its thickness direction coinciding with the surface of the first insertion plate portion 32 of the top foil 30 that is located on one side in the thickness direction.

[0050] The length of the wear-inhibiting member 60 in the axial direction A is the same as the length of the first insertion plate portion 32 of the top foil 30. Both end faces 60a of the wear-inhibiting member 60 in the axial direction A are located on the same plane as both end faces 32a of the first insertion plate portion 32 in the axial direction A. The wear-inhibiting member 60 faces each of the anti-slip members 50 in the axial direction A. The wear-inhibiting members 60 are provided between the first insertion plate portion 32 and the second insertion plate portion 41 so as to be able to come into contact with the anti-slip members 50.

[0051] [Operation of the embodiment] Next, the operation of this embodiment will be described. 2, when the rotating shaft 103 rotates in a rotation direction D and the rotation speed of the rotating shaft 103 reaches a predetermined rotation speed, an air film 105 is formed between the rotating shaft 103 and the top foil 30. As a result, the rotating shaft 103 floats above the top foil 30. Then, the rotating shaft 103 is supported in the radial direction Rd by the air film 105 in a non-contact state with the top foil 30.

[0052] When the rotating shaft 103 rotates, it is considered that the rotating shaft 103 is inclined with respect to the axis of the bearing housing 20. When the rotating shaft 103 is inclined with respect to the axis of the bearing housing 20, the thickness of the air film 105 changes in the axial direction A. Then, in the axial direction A, there are formed areas where the dynamic pressure in the radial direction Rd by the air film 105 is low and areas where it is high. Therefore, a force that moves in the axial direction A acts on the top foil 30 and the bump foil 40. This may cause the top foil 30 and the bump foil 40 to move in the axial direction A and come into contact with the retaining member 50 so as to be pressed more than necessary.

[0053] 6, when the bump foil 40 moves in the axial direction A, each opposing portion 42 of the bump foil 40 comes into contact with the opposing surface 50a. When the bump foil 40 moves in the axial direction A and the opposing portions 42 of the bump foil 40 come into contact with the opposing surfaces 50a of the respective retaining members 50, a spring action is generated in the opposing portions 42, and the load acting on the opposing surfaces 50a of the retaining members 50 is absorbed. Therefore, wear of the bump foil 40 and the retaining members 50 is suppressed.

[0054] Furthermore, as the opposing portion 42 undergoes elastic deformation, the opposing portion 42 comes into surface contact with the retaining member 50. This increases the contact area between the bump foil 40 and the retaining member 50. This prevents a load from acting locally on the retaining member 50. As a result, wear of the bump foil 40 and the retaining member 50 is suppressed.

[0055] When the top foil 30 moves in the axial direction A, both end faces 60a of the wear-suppressing member 60 in the axial direction A and both end faces 32a of the first insertion plate portion 32 in the axial direction A come into contact with the opposing surfaces 50a of the respective retaining members 50. Therefore, for example, compared with the case where the first insertion plate portion 32 comes into contact with the opposing surfaces 50a of the respective retaining members 50 in a state where the wear-suppressing member 60 is not provided in the first insertion plate portion 32, the contact area with the opposing surfaces 50a of the respective retaining members 50 is increased. Therefore, it is possible to prevent a load from acting locally on the opposing surfaces 50a of the respective retaining members 50. In this way, the wear-suppressing member 60 provided in the first insertion plate portion 32 suppresses wear between the first insertion plate portion 32 and the retaining members 50. Therefore, the wear-suppressing member 60 suppresses wear between the first insertion plate portion 32 and the retaining members 50.

[0056] [Effects of the embodiment] The above embodiment can provide the following effects. (1) The first insertion plate portion 32 is provided with a wear-suppressing member 60 that faces the retaining member 50 in the axial direction A and suppresses wear between the retaining member 50 and the first insertion plate portion 32. This suppresses wear between the first insertion plate portion 32 and the retaining member 50 by the wear-suppressing member 60. This makes it possible to suppress the position of the top foil 30 relative to the bearing housing 20 from shifting in the axial direction A of the bearing housing 20. As a result, the rotating shaft 103 can be stably supported.

[0057] (2) Both the first insertion plate portion 32 and the second insertion plate portion 41 are inserted into the groove 20b. The wear-inhibiting member 60 is provided between the first insertion plate portion 32 and the second insertion plate portion 41 so as to be able to come into contact with the retaining member 50. As a result, the wear-inhibiting member 60 comes into contact with the retaining member 50 between the first insertion plate portion 32 and the second insertion plate portion 41, thereby making it possible to inhibit wear between the first insertion plate portion 32 and the retaining member 50.

[0058] (3) The wear-suppressing member 60 is provided on the first insertion plate portion 32 of the top foil 30. The second insertion plate portion 41 is provided with the facing portion 42 that is bent and formed so as to face the retaining member 50 in the axial direction A. With this, when the bump foil 40 moves in the axial direction A of the bearing housing 20 and the facing portion 42 comes into contact with the retaining member 50, a spring action is generated in the facing portion 42, and the load acting on the retaining member 50 is absorbed. Therefore, wear of the second insertion plate portion 41 and the retaining member 50 can be suppressed. Meanwhile, wear between the first insertion plate portion 32 and the retaining member 50 is suppressed by the wear-suppressing member 60. As a result, wear between the first insertion plate portion 32 and the second insertion plate portion 41 and the retaining member 50 can be suppressed.

[0059] (4) The hardness of the wear-preventing member 60 is lower than the hardness of the first insertion plate portion 32 of the top foil 30. This makes it possible to prevent the anti-slip member 50 from being worn down when the wear-preventing member 60 comes into contact with the anti-slip member 50.

[0060] (5) Both end faces 60a in the axial direction A of the wear-suppressing member 60 are located on the same plane as both end faces 32a in the axial direction A of the first insertion plate portion 32 of the top foil 30. As a result, both end faces 60a in the axial direction A of the bearing housing 20 of the wear-suppressing member 60 and both end faces 32a in the axial direction A of the bearing housing 20 of the first insertion plate portion 32 contact the opposing surfaces 50a of each of the retaining members 50. Therefore, for example, compared with the case where the first insertion plate portion 32 contacts the opposing surfaces 50a of each of the retaining members 50 in a state where the wear-suppressing member 60 is not provided in the first insertion plate portion 32, the contact area with the opposing surfaces 50a of each of the retaining members 50 is increased. Therefore, it is possible to suppress the load from acting locally on the opposing surfaces 50a of each of the retaining members 50. In this way, the wear-suppressing member 60 is provided in the first insertion plate portion 32, thereby suppressing wear between the first insertion plate portion 32 and the retaining members 50.

[0061] (6) The bump foil 40 is formed by bending a long, flexible metal plate material in a substantially arc shape in the circumferential direction B. At this time, the bending process is performed so as to form a plurality of valleys 43 and a plurality of peaks 44, so the number of steps of the bending process is greater than that of the top foil 30. Therefore, the bending process of bending the metal plate material to provide the facing portion 42 on the second insertion plate portion 41 of the bump foil 40 can be performed simultaneously with the existing bending process. Therefore, compared to the case where the facing portion 42 is provided on the first insertion plate portion 32 of the top foil 30, which requires less bending, for example, the processing effort can be reduced. Furthermore, by providing the wear-suppressing member 60 on the first insertion plate portion 32 of the top foil 30, wear between the first insertion plate portion 32 and the retaining member 50 can be suppressed even if the facing portion 42 is not provided on the first insertion plate portion 32 of the top foil 30.

[0062] [Example of change] The above embodiment can be modified as follows: The above embodiment and the following modifications can be combined with each other to the extent that no technical contradiction occurs.

[0063] As shown in FIG. 7, the length of the wear-suppressing member 60 in the axial direction A may be longer than the length of the first insertion plate portion 32 of the top foil 30 in the axial direction A. Both end faces 60a of the wear-suppressing member 60 in the axial direction A protrude from both end faces 32a of the first insertion plate portion 32 of the top foil 30 in the axial direction A. The wear-suppressing member 60 is made of resin. The hardness of the wear-suppressing member 60 is lower than the hardness of the first insertion plate portion 32 of the top foil 30. Therefore, the hardness of both end parts of the wear-suppressing member 60 in the axial direction A is lower than the hardness of the first insertion plate portion 32 of the top foil 30. In this way, the hardness of at least both end parts of the wear-suppressing member 60 in the axial direction A may be lower than the hardness of the first insertion plate portion 32.

[0064] This makes it possible to reduce the load acting on the opposing surfaces 50a of the respective anti-slip members 50, even if both ends of the anti-slip member 60 come into contact with the opposing surfaces 50a of the respective anti-slip members 50. In this manner, by providing the anti-slip member 60 on the first insertion plate portion 32, it is possible to suppress wear between the first insertion plate portion 32 and the anti-slip members 50.

[0065] 8, the wear-suppressing member 60 may have a configuration in which the hardness of the first insertion plate portion 32 is the same as that of the first insertion plate portion 32 except for both ends in the axial direction A, and the hardness of the first insertion plate portion 32 is lower than that of the first insertion plate portion 32. The wear-suppressing member 60 is formed of a metal plate 61 having the same hardness as that of the first insertion plate portion 32 except for both ends in the axial direction A. The wear-suppressing member 60 has both ends in the axial direction A formed of a resin portion 62. The resin portions 62 are bonded to both end faces of the metal plate 61, respectively, by, for example, an adhesive or the like.

[0066] According to this, the hardness of the wear-suppressing member 60 other than at both ends in the axial direction A is the same as the hardness of the first insertion plate portion 32, so that the strength of the wear-suppressing member 60 can be ensured as much as possible. Even if both ends of the wear-suppressing member 60 come into contact with the opposing surfaces 50a of each of the stopper members 50, the load acting on the opposing surfaces 50a of each of the stopper members 50 can be reduced. In this way, by providing the wear-suppressing member 60 to the first insertion plate portion 32, wear between the first insertion plate portion 32 and the stopper members 50 can be suppressed.

[0067] 9 and 10 , the wear-suppressing member 60 may be annular and surround the periphery of the first insertion plate portion 32 of the top foil 30. The wear-suppressing member 60 covers the entire end faces 32a of the first insertion plate portion 32 in the axial direction A and surrounds the entire outer surface of the first insertion plate portion 32. In this manner, the wear-suppressing member 60 may surround at least the end faces 32a of the first insertion plate portion 32 in the axial direction A. The wear-suppressing member 60 extends from between the first insertion plate portion 32 and the second insertion plate portion 41 to between the first insertion plate portion 32 and the groove 20b, and is provided so as to be able to come into contact with the retaining member 50.

[0068] As shown in Fig. 10, the wear reducing member 60 is in contact with the second cutout edge 312a. This prevents the wear reducing member 60 from falling out of the first insertion plate portion 32 to the inside in the radial direction C. Furthermore, the length in the axial direction A of the gap between the inner circumferential surface of the wear reducing member 60 and the first cutout edge 311a is shorter than the length in the axial direction A at the second cutout edge 312a. This prevents the wear reducing member 60 from falling out of the first insertion plate portion 32 to the inside in the radial direction C even if the wear reducing member 60 rattles in the axial direction A relative to the first insertion plate portion 32.

[0069] With this, for example, compared to a case where the first insertion plate portion 32 contacts the opposing surface 50a of each of the retaining members 50 in a state where the wear-inhibiting member 60 is not provided on the first insertion plate portion 32, the contact area with the opposing surface 50a of each of the retaining members 50 is increased. This prevents a load from acting locally on the opposing surface 50a of each of the retaining members 50. In this way, by providing the wear-inhibiting member 60 on the first insertion plate portion 32, wear between the first insertion plate portion 32 and the retaining members 50 can be suppressed.

[0070] In this manner, the wear prevention member 60 is annularly configured to surround the periphery of the first insertion plate portion 32, which is preferable as a configuration that surrounds at least both end faces 32a of the first insertion plate portion 32 in the axial direction A of the bearing housing 20.

[0071] The wear-inhibiting member 60 extends from between the first insertion plate portion 32 and the second insertion plate portion 41 to between the first insertion plate portion 32 and the groove 20b, and is provided so as to be able to come into contact with the retaining member 50. With this, the wear-inhibiting member 60 comes into contact with the retaining member 50 in a state in which it extends from between the first insertion plate portion 32 and the second insertion plate portion 41 to between the first insertion plate portion 32 and the groove 20b, thereby suppressing wear between the first insertion plate portion 32 and the retaining member 50.

[0072] 11 , the wear-suppressing member 60 may be non-annular and surround the periphery of the first insertion plate portion 32 of the top foil 30. Even if the wear-suppressing member 60 is non-annular, it is sufficient that the wear-suppressing member 60 surrounds at least both end faces 32a of the first insertion plate portion 32 in the axial direction A.

[0073] As shown in Fig. 12, the wear-reducing member 60 may have a ring-shaped main body 63 surrounding the first insertion plate 32 and a first coating layer 64 provided on the outer circumferential surface of the main body 63. In this manner, the first coating layer 64 may be formed on the outer circumferential surface of the wear-reducing member 60. The main body 63 is made of resin. The first coating layer 64 is formed by coating the outer circumferential surface of the main body 63 with a resin having a lower hardness than the main body 63. Therefore, the hardness of the first coating layer 64 is lower than the hardness of the main body 63.

[0074] According to this, for example, the load acting on the opposing surfaces 50a of each anti-slip members 50 can be reduced compared to a case in which the wear-preventing member 60 does not have the first coating layer 64 and the main body portion 63 contacts the opposing surfaces 50a of each anti-slip members 50.

[0075] A first coating layer 64 is formed on the outer circumferential surface of the wear-inhibiting member 60. With this, the first coating layer 64 can further prevent the anti-slip member 50 from being worn down when the wear-inhibiting member 60 comes into contact with the anti-slip member 50.

[0076] As shown in FIG. 13, the wear-suppressing member 60 may further include a second coating layer 65 provided between the inner circumferential surface of the main body 63 and the first insertion plate 32 in addition to the configuration of the embodiment shown in FIG. 12. The second coating layer 65 is formed by coating the inner circumferential surface of the main body 63 with a resin having a lower hardness than the main body 63. Therefore, the hardness of the second coating layer 65 is lower than the hardness of the main body 63. In this manner, the second coating layer 65 may be formed on the outer circumferential surface of the first insertion plate 32. The second coating layer 65 formed on the outer circumferential surface of the first insertion plate 32 is covered with the wear-suppressing member 60. According to this, the second coating layer 65 can prevent wear between the main body 63 and the first insertion plate 32. Therefore, the durability of at least one of the first insertion plate and the second insertion plate and the wear-suppressing member can be improved.

[0077] As shown in FIG. 14, the wear-suppressing members 60 may be configured to surround both end faces 32a of the first insertion plate portion 32 in the axial direction A by sandwiching both end faces 32a of the first insertion plate portion 32 in the axial direction A. The wear-suppressing members 60 extend from between the first insertion plate portion 32 and the second insertion plate portion 41 to between the first insertion plate portion 32 and the groove 20b, and are provided so as to be able to come into contact with the retaining member 50. The wear-suppressing members 60 sandwiching both end faces 32a of the first insertion plate portion 32 in the axial direction A are fixed to the end faces 32a of the first insertion plate portion 32 by, for example, crimping the end faces 32a of the first insertion plate portion 32. The wear-suppressing members 60 may be fixed to the end faces 32a of the first insertion plate portion 32 by, for example, welding. The wear-suppressing members 60 cover the entire both end faces 32a of the first insertion plate portion 32 in the axial direction A. In this manner, the configuration in which the wear-reducing member 60 clamps each of the two axial end portions 32a of the bearing housing 20 in the first insertion plate portion 32 is preferable as a configuration in which the wear-reducing member 60 surrounds both end surfaces 32a of the bearing housing 20 in the axial direction A in the first insertion plate portion 32.

[0078] As shown in FIG. 15, the wear-suppressing member 60 may be a rubber material covering the first insertion plate portion 32. The wear-suppressing member 60 covers the entire end faces 32a of the first insertion plate portion 32 in the axial direction A and surrounds the entire outer surface of the first insertion plate portion 32. The wear-suppressing member 60 extends from between the first insertion plate portion 32 and the second insertion plate portion 41 to between the first insertion plate portion 32 and the groove 20b, and is provided so as to be able to come into contact with the retaining member 50. In this manner, the configuration in which the wear-suppressing member 60 is a rubber material covering the first insertion plate portion 32 is suitable as a configuration for reducing the load acting on the opposing surfaces 50a of the retaining members 50.

[0079] 16, in addition to the configuration of the embodiment shown in Fig. 13, a second coating layer 65 may be formed on the bearing surface 30a of the top foil 30. That is, the second coating layer 65 may be formed on the bearing surface 30a of the top foil 30 and the outer circumferential surface of the first insertion plate portion 32. The hardness of the first coating layer 64 is smaller than the hardness of the second coating layer 65.

[0080] According to this, while the wear of the bearing surface 30a of the top foil 30 is suppressed by the second coating layer 65, the wear between the first insertion plate portion 32 and the wear-suppressing member 60 can also be suppressed by the second coating layer 65.

[0081] Furthermore, the hardness of the first coating layer 64 is smaller than the hardness of the second coating layer 65. This makes it possible to suppress wear powder generated by the wear of the first coating layer 64 from promoting wear of the second coating layer 65. Therefore, it is possible to avoid a problem in which the bearing surface 30a of the top foil 30 is worn due to wear of the second coating layer 65.

[0082] 9, 10, 11, 12, and 13, the wear-inhibiting member 60 may be annular so as to surround not only the first insertion plate portion 32 of the top foil 30 but also the second insertion plate portion 41 of the bump foil 40. In this case, the second insertion plate portion 41 of the bump foil 40 does not need to be provided with the opposing portion 42. What is important is that the wear-inhibiting member 60 is provided on at least one of the first insertion plate portion 32 and the second insertion plate portion 41.

[0083] 14 , the wear suppressing member 60 may be configured to sandwich both ends in the axial direction A of the second insertion plate portion 41 of the bump foil 40, in addition to both ends in the axial direction A of the first insertion plate portion 32 of the top foil 30. In this case, the second insertion plate portion 41 of the bump foil 40 does not need to be provided with the opposing portion 42.

[0084] 15 , the wear-suppressing member 60 may be a rubber material that covers not only the first insertion plate portion 32 of the top foil 30 but also the periphery of the second insertion plate portion 41 of the bump foil 40. In this case, the second insertion plate portion 41 of the bump foil 40 does not need to be provided with the opposing portion 42.

[0085] In the above embodiment, the wear-inhibiting member 60 may be provided on a surface of the first insertion plate portion 32 of the top foil 30 opposite to the second insertion plate portion 41 of the bump foil 40 .

[0086] In the embodiment, the wear suppressing member 60 may be provided on one surface in the thickness direction of the second insertion plate portion 41 of the bump foil 40. In this case, the second insertion plate portion 41 of the bump foil 40 does not need to be provided with the opposing portion 42.

[0087] 7 and 8, the wear suppressing member 60 may be provided on one surface in the thickness direction of the second insertion plate portion 41 of the bump foil 40. In this case, the second insertion plate portion 41 of the bump foil 40 does not need to be provided with the opposing portion 42.

[0088] In the embodiment, the wear-suppressing member 60 may be made of metal. In other words, the material of the wear-suppressing member 60 is not limited to resin. For example, when the wear-suppressing member 60 is made of metal, the wear-suppressing member 60 is formed of a metal having a lower hardness than the material of the top foil 30.

[0089] In the embodiment, the material of the wear-suppressing member 60 may be the same as the material of the top foil 30. In short, the hardness of the wear-suppressing member 60 may be the same as the hardness of the first insertion plate portion 32 of the top foil 30. Even in this case, it is sufficient that both end faces 60a of the wear-suppressing member 60 in the axial direction A are located on the same plane as both end faces 32a of the first insertion plate portion 32 of the top foil 30 in the axial direction A. According to this, the contact area with the opposing surfaces 50a of each of the retaining members 50 is increased compared to the case where the first insertion plate portion 32 contacts the opposing surfaces 50a of each of the retaining members 50 in a state where the wear-suppressing member 60 is not provided in the first insertion plate portion 32. Therefore, it is possible to suppress the load from acting locally on the opposing surfaces 50a of each of the retaining members 50.

[0090] In the above embodiment, the opposing portions 42 may extend in opposite directions in the circumferential direction B. In the embodiment, for example, the wear-inhibiting member 60 may not be provided on the first insertion plate portion 32 of the top foil 30, and the opposing portion 42 may be provided on the first insertion plate portion 32 of the top foil 30. The opposing portion 42 may not be provided on the second insertion plate portion 41 of the bump foil 40, and the wear-inhibiting member 60 may be provided on the second insertion plate portion 41 of the bump foil 40. In short, it is sufficient that the wear-inhibiting member 60 is provided on at least one of the first insertion plate portion 32 and the second insertion plate portion 41.

[0091] In the embodiment, the second insertion plate portion 41 of the bump foil 40 may not be provided with the opposing portion 42, and the wear-suppressing member 60 may be provided on the second insertion plate portion 41 in addition to the first insertion plate portion 32. In short, it is sufficient that the wear-suppressing member 60 is provided on at least one of the first insertion plate portion 32 and the second insertion plate portion 41.

[0092] In the embodiment, for example, the opposing portion 42 may be provided on only one side of the second insertion plate portion 41 in the axial direction A. Therefore, it is sufficient that the opposing portion 42 is provided on at least one of both ends of the second insertion plate portion 41 in the axial direction A.

[0093] In the above embodiment, the retaining member 50 may be press-fitted into the groove 20b. In the embodiment, one of the pair of retaining members 50 may be omitted. In this case, it is preferable to close the portion of the groove 20b that opens toward the first end 21 side or the second end 22 side. The portion of the groove 20b that is closed in the axial direction A is part of the bearing housing 20. The portion of the groove 20b that is closed in the axial direction A may be used as the retaining portion. In other words, the bearing housing 20 may have the retaining portion. When the portion of the groove 20b that is closed in the axial direction A is used as the retaining portion, the retaining portion has an opposing surface that faces the first insertion plate portion 32 and the second insertion plate portion 41 in the axial direction A.

[0094] In the embodiment, the foil bearing 10 is configured to include three bump foils 40, but this is not limited thereto, and the foil bearing 10 may be configured to include one substantially cylindrical bump foil 40. In this case, the bearing housing 20 may have only one groove 20b.

[0095] In the embodiment, for example, the first insertion plate portion 32 may be formed on both ends of the top foil 30. In short, it is only necessary that the first insertion plate portion 32 is formed on at least one end of the top foil 30.

[0096] In the embodiment, for example, the second insertion plate portion 41 may be formed on both ends of the bump foil 40. In other words, it is only necessary that the second insertion plate portion 41 is formed on at least one end of the bump foil 40.

[0097] In the above-described embodiment, the foil bearing 10 is not limited to a bearing that supports the rotating shaft 103 of the centrifugal compressor 100 in the radial direction Rd. In other words, the application of the foil bearing 10 may be changed as appropriate.

[0098] [Note] The above embodiment includes the configurations described in the following supplementary notes. <Appendix 1> a cylindrical bearing housing through which a rotating shaft is inserted; A thin top foil disposed between the rotating shaft and the bearing housing; a thin-plate-shaped bump foil that is disposed between the bearing housing and the top foil and elastically supports the top foil, A groove is formed on an inner peripheral surface of the bearing housing, the groove opening at an axial end of the bearing housing, At least one end of the top foil is formed with a first insertion plate portion that is bent toward the groove and inserted into the groove, At least one end of the bump foil is formed with a second insertion plate portion that is bent toward the groove and inserted into the groove, A foil bearing including a pair of retaining portions that overlap the first insertion plate portion and the second insertion plate portion in the axial direction and cover the groove, A foil bearing according to claim 1, characterized in that at least one of the first insertion plate portion and the second insertion plate portion is provided with a wear suppressing member that faces the retaining portion in the axial direction and suppresses wear between the retaining portion and the foil bearing.

[0099] <Appendix 2> The wear suppressing member has a thin plate shape extending in the axial direction and is provided on at least one of the first insertion plate portion and the second insertion plate portion in a state where a thickness direction of the wear suppressing member coincides with a surface located on one side of a thickness direction of at least one of the first insertion plate portion and the second insertion plate portion, The axial length of the wear reducing member is the same as the axial length of at least one of the first insertion plate portion and the second insertion plate portion, A foil bearing as described in <Appendix 1>, characterized in that both axial end faces of the wear-reducing member are located on the same plane as both axial end faces of at least one of the first insertion plate portion and the second insertion plate portion.

[0100] According to this, both axial end faces of the wear-inhibiting member and both axial end faces of the bearing housing of at least one of the first and second insertion plates come into contact with the retaining portion. Therefore, the contact area with the retaining portion is increased compared to a case where at least one of the first and second insertion plates contacts the retaining portion when no wear-inhibiting member is provided on at least one of the first and second insertion plates. This prevents a load from acting locally on the retaining portion. In this way, by providing a wear-inhibiting member on at least one of the first and second insertion plates, wear between at least one of the first and second insertion plates and the retaining portion can be suppressed.

[0101] <Appendix 3> The wear suppressing member has a thin plate shape extending in the axial direction and is provided on at least one of the first insertion plate portion and the second insertion plate portion in a state where a thickness direction of the wear suppressing member coincides with a surface located on one side of a thickness direction of at least one of the first insertion plate portion and the second insertion plate portion, The axial length of the wear reducing member is longer than the axial length of at least one of the first insertion plate portion and the second insertion plate portion, Both end surfaces in the axial direction of the wear reducing member protrude beyond both end surfaces in the axial direction of at least one of the first insertion plate portion and the second insertion plate portion, The foil bearing described in <Appendix 1>, characterized in that the hardness of at least both ends of the wear-reducing member in the axial direction is lower than the hardness of at least one of the first insertion plate portion and the second insertion plate portion.

[0102] According to this, the hardness of at least both ends of the wear-inhibiting member in the axial direction of the bearing housing is lower than the hardness of at least one of the first and second insertion plate portions. Therefore, even if both ends of the wear-inhibiting member come into contact with the retaining portion, the load acting on the retaining portion can be reduced. In this way, by providing the wear-inhibiting member on at least one of the first and second insertion plate portions, wear between the retaining portion and at least one of the first and second insertion plate portions can be suppressed.

[0103] <Appendix 4> The foil bearing described in <Appendix 3> is characterized in that the hardness of the wear-reducing member other than both axial ends is the same as the hardness of at least one of the first insertion plate portion and the second insertion plate portion, and the hardness of both axial ends is lower than the hardness of at least one of the first insertion plate portion and the second insertion plate portion.

[0104] According to this, the hardness of the wear-suppressing member other than both ends in the axial direction of the bearing housing is the same as the hardness of at least one of the first and second insertion plate portions, so that the strength of the wear-suppressing member can be ensured as much as possible. Furthermore, the hardness of both ends in the axial direction of the bearing housing of the wear-suppressing member is lower than the hardness of at least one of the first and second insertion plate portions. Therefore, even if both ends of the wear-suppressing member come into contact with the retaining portion, the load acting on the retaining portion can be reduced. In this way, by providing the wear-suppressing member to at least one of the first and second insertion plate portions, wear between the retaining portion and at least one of the first and second insertion plate portions can be suppressed.

[0105] <Appendix 5> The foil bearing described in <Appendix 1>, characterized in that the wear-reducing member surrounds at least both end faces in the axial direction of at least one of the first insertion plate portion and the second insertion plate portion.

[0106] With this, for example, the contact area with the retaining portion is increased compared to when at least one of the first and second insertion plate portions contacts the retaining portion when no wear-inhibiting member is provided on at least one of the first and second insertion plate portions. This prevents a load from acting locally on the retaining portion. In this way, by providing a wear-inhibiting member on at least one of the first and second insertion plate portions, wear between at least one of the first and second insertion plate portions and the retaining portion can be suppressed.

[0107] <Appendix 6> The foil bearing described in <Appendix 5>, characterized in that the wear-reducing member is annular and surrounds at least one of the first insertion plate portion and the second insertion plate portion.

[0108] In this way, a configuration in which the wear-reducing member is annular and surrounds at least one of the first insertion plate portion and the second insertion plate portion is preferred as a configuration that surrounds at least both axial end faces of the bearing housing in at least one of the first insertion plate portion and the second insertion plate portion.

[0109] <Appendix 7> The wear-suppressing member is an annular main body portion surrounding at least one of the first insertion plate portion and the second insertion plate portion; a first coating layer provided on an outer circumferential surface of the main body; The foil bearing described in <Appendix 6>, characterized in that the hardness of the first coating layer is lower than the hardness of the main body portion.

[0110] This makes it possible to reduce the load acting on the retaining portion, compared to, for example, a case in which the wear-inhibiting member does not have the first coating layer and the main body contacts the retaining portion.

[0111] <Appendix 8> The wear reducing member further includes a second coating layer provided between an inner circumferential surface of the main body and at least one of the first insertion plate portion and the second insertion plate portion, The foil bearing described in <Appendix 7>, characterized in that the hardness of the second coating layer is lower than the hardness of the main body portion.

[0112] According to this, the second coating layer can prevent wear between the main body and at least one of the first and second insertion plates, thereby improving the durability of at least one of the first and second insertion plates and the wear-suppressing member.

[0113] <Appendix 9> The foil bearing described in <Appendix 5> is characterized in that the wear-reducing member surrounds both end faces in the axial direction of at least one of the first insertion plate portion and the second insertion plate portion by sandwiching each of both end ends in the axial direction of at least one of the first insertion plate portion and the second insertion plate portion.

[0114] In this way, the configuration in which the wear-reducing member clamps each of both axial end portions of the bearing housing in at least one of the first insertion plate portion and the second insertion plate portion is preferable as a configuration in which the wear-reducing member surrounds both axial end faces of the bearing housing in at least one of the first insertion plate portion and the second insertion plate portion.

[0115] <Appendix 10> The foil bearing described in <Appendix 1>, characterized in that the wear-reducing member is a rubber material that covers at least one of the first insertion plate portion and the second insertion plate portion.

[0116] In this manner, a configuration in which the wear-suppressing member is a rubber material that covers at least one of the first insertion plate portion and the second insertion plate portion is suitable as a configuration for reducing the load acting on the retaining portion. <Appendix 11> The wear suppressing member is provided on the first insertion plate portion, The foil bearing according to any one of <Appendix 1> to <Appendix 10>, characterized in that the second insertion plate portion is provided with an opposing portion that is bent so as to face the retaining portion in the axial direction. This provides the same effect as claim 4. [Explanation of symbols]

[0117] 10...foil bearing, 20...bearing housing, 20a...inner surface, 20b...groove, 21...first end as axial end of bearing housing, 22...second end as axial end of bearing housing, 30...top foil, 30a...bearing surface, 32...first insertion plate portion, 40...bump foil, 41...second insertion plate portion, 42...opposing portion, 50...anti-slip member as anti-slip portion, 60...wear-inhibiting member, 64...first coating layer, 65...second coating layer, 103...rotating shaft.

Claims

1. a cylindrical bearing housing through which a rotating shaft is inserted; A thin top foil disposed between the rotating shaft and the bearing housing; a thin-plate-shaped bump foil that is disposed between the bearing housing and the top foil and elastically supports the top foil, A groove is formed on an inner peripheral surface of the bearing housing, the groove opening at an axial end of the bearing housing, At least one end of the top foil is formed with a first insertion plate portion that is bent toward the groove and inserted into the groove, At least one end of the bump foil is formed with a second insertion plate portion that is bent toward the groove and inserted into the groove, A foil bearing including a pair of retaining portions overlapping the first insertion plate portion and the second insertion plate portion in the axial direction and covering the groove, A foil bearing characterized in that at least one of the first insertion plate portion and the second insertion plate portion is provided with a wear-suppressing member that faces the anti-slip portion in the axial direction and suppresses wear between the anti-slip portion and the foil bearing.

2. Both the first insertion plate portion and the second insertion plate portion are inserted into the groove, The foil bearing according to claim 1 , wherein the wear-suppressing member is provided between the first insertion plate portion and the second insertion plate portion so as to be able to come into contact with the retaining portion.

3. The foil bearing according to claim 2, characterized in that the wear-reducing member extends from between the first insertion plate portion and the second insertion plate portion to between the first insertion plate portion and the groove, and is arranged so as to be able to come into contact with the anti-pullout portion.

4. The wear suppressing member is provided on the first insertion plate portion, The foil bearing according to claim 1 , wherein the second insertion plate portion is provided with an opposing portion that is bent so as to face the retaining portion in the axial direction.

5. The foil bearing according to claim 4 , wherein the hardness of the wear-suppressing member is lower than the hardness of the first insertion plate portion.

6. The foil bearing according to claim 5, characterized in that a first coating layer is formed on an outer circumferential surface of the wear-suppressing member.

7. A second coating layer is formed on the bearing surface of the top foil and the outer circumferential surface of the first insertion plate portion, The foil bearing according to claim 6, wherein the second coating layer formed on the outer circumferential surface of the first insertion plate portion is covered with the wear-suppressing member.

8. The foil bearing according to claim 7 , wherein the hardness of the first coating layer is less than the hardness of the second coating layer.

Images