Tilting Pad Bearing

Abstract

To achieve, with a simple structure, both a structure that enables supply of a fluid to a pad and a structure that biases the pad toward a rotary shaft.SOLUTION: A tilting pad bearing includes: a plurality of pads slidably supporting an outer peripheral surface of a rotary shaft; a housing covering the plurality of pads; a support portion supporting the pad in such a manner that the pad may swing relative to the housing; and a fluid supply unit which supplies a fluid to a pad surface. The support portion includes: a pivot having a pad support surface in contact with a pad outer peripheral surface, and a pivot curved surface which is curved facing and protruding toward a side opposite to the pad support surface; a liner part having a first liner surface in contact with the pivot curved surface; and a biasing member which biases the liner part toward the pivot relative to the housing.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present disclosure relates to tilting pad bearings. [Background technology]

[0002] Rotary machines, including gas turbines, steam turbines, and centrifugal compressors, include a rotating shaft that rotates about an axis and a casing that surrounds the rotating shaft. The rotating shaft is rotatably supported by a bearing device. Widely used bearing devices include journal bearings that support radial loads on the rotating shaft and thrust bearings that support axial loads on the rotating shaft. A well-known example of a journal bearing is a tilting pad bearing with multiple pads.

[0003] For example, Patent Document 1 describes a tilting pad bearing that includes a pad, a liner that supports the pad, and a pivot that supports the liner and thereby allows the pad to swing. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent Publication No. 2019-82233 Summary of the Invention [Problem to be solved by the invention]

[0005] Incidentally, tilting pad bearings sometimes require increased bearing rigidity to improve the stability of the rotating shaft and reduce shaft vibration. In order to increase bearing rigidity, the radial gap between the pads and the rotating shaft must be reduced during assembly. However, reducing the gap between the pads and the rotating shaft increases heat generation due to friction between the pads and the rotating shaft as the rotating shaft rotates. As a result, the pads and the rotating shaft thermally expand, increasing the likelihood of direct contact between the pads and the rotating shaft. To avoid such contact, a design has been considered in which the pads are biased toward the rotating shaft by a spring to apply pressure, and the spring can move the pads away from the rotating shaft when the pads or the rotating shaft expand.

[0006] However, with this type of structure, the pads are in contact with the rotating shaft when the rotating shaft starts rotating from a completely stopped state. Therefore, to prevent contact between the pads and the rotating shaft during starting and stopping, a fluid such as gas or oil may be supplied between the pads and the rotating shaft to lift the pads away from the rotating shaft by static pressure. In this case, it is necessary to combine a structure that allows the supply of a fluid such as gas or oil to the pads with a structure that biases the pads toward the rotating shaft.

[0007] The present disclosure has been made to solve the above-mentioned problems, and aims to provide a tilting pad bearing that can combine, with a simple structure, a structure that allows fluid to be supplied to the pad and a structure that urges the pad toward the rotation axis. [Means for solving the problem]

[0008] In order to solve the above problems, a tilting pad bearing according to the present disclosure includes a plurality of pads each having a pad surface that slidably supports an outer circumferential surface of a rotary shaft that rotates about an axis, a housing formed in an annular shape about the axis so as to cover the plurality of pads, a support portion that is arranged between the housing and the pads in a radial direction based on the axis and supports the pads so as to be able to swing relative to the housing, and a fluid supply portion that supplies fluid to the pad surface from outside the housing, wherein the pads have a pad outer circumferential surface that faces the opposite side to the pad surface in the radial direction, the housing has a housing accommodating recess that can accommodate the support portion, and the support portion has a pad support surface that contacts the pad outer circumferential surface a liner portion disposed between the housing and the pivot, the liner portion having a first liner surface that is formed linearly and contacts the pivot curved surface when viewed in a circumferential direction centered on the axis, the liner portion being disposed between the housing and the pivot; and a biasing member disposed between the liner portion and the housing and biasing the liner portion toward the pivot relative to the housing, the fluid supply portion having a pad flow path formed in the pad so as to open at the pad surface, a pivot flow path formed in the pivot so as to communicate with the pad flow path, and a housing flow path formed in the housing so as to communicate with the pivot flow path. The pivot has a pivot side surface facing a direction intersecting the pad support surface and the pivot curved surface, the housing flow path supplies the fluid toward the pivot side surface, and the pivot flow path has a pivot recess recessed in the radial direction from the pad support surface and communicating with the pad flow path, and a pivot internal flow path formed in the pivot so as to communicate the pivot recess and the pivot side surface. . [Effects of the Invention]

[0009] According to the tilting pad bearing of the present disclosure, it is possible to achieve both a structure that allows fluid to be supplied to the pad and a structure that urges the pad toward the rotation shaft with a simple structure. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a cross-sectional view showing a schematic configuration of a tilting pad bearing according to an embodiment of the present disclosure, as viewed from the axial direction. FIG. [Figure 2]2 is a cross-sectional view of a main part taken along line II-II in FIG. 1 (as viewed from the circumferential direction) showing the configuration of the pad and its periphery according to the first embodiment. FIG. [Figure 3] FIG. 1 is a perspective view illustrating a configuration of a pivot according to an embodiment of the present disclosure. [Figure 4] 4 is a cross-sectional view taken along line IV-IV in FIG. 2 (viewed from the radial direction) illustrating the relationship between the liner and the housing according to the embodiment of the present disclosure. [Figure 5] FIG. 10 is a cross-sectional view of a main part, seen from the circumferential direction, showing the configuration of the periphery of a pad according to a second embodiment. [Figure 6] FIG. 10 is a cross-sectional view of a main part, seen from the circumferential direction, showing the configuration of the periphery of a pad according to a third embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, an embodiment of a tilting pad bearing according to the present disclosure will be described with reference to the accompanying drawings. However, the present disclosure is not limited to this embodiment.

[0012] First Embodiment (Configuration of tilting pad bearing) The tilting pad bearing 1 is a bearing for rotatably supporting a rotating shaft 100 of a rotary machine including, for example, a gas turbine, a steam turbine, or a compressor. The tilting pad bearing 1 is a device for supporting the load of the rotating shaft 100 in the radial direction Dr of the rotating shaft 100. As shown in FIG. 1, the tilting pad bearing 1 includes a pad 2, a housing 3, a support portion 4, a fluid supply portion 5 (see FIG. 2), and a seal member 44.

[0013] For the sake of convenience in the following explanation, the direction in which the axis O extends will be referred to as the axial direction Da of the rotating shaft 100 and the tilting pad bearing 1. The radial direction of the rotating shaft 100 and the tilting pad bearing 1 based on the axis O will be referred to simply as the radial direction Dr. The side of the radial direction Dr that approaches the axis O will be referred to as the inner side Dri of the radial direction Dr, and the side of the radial direction Dr opposite the inner side Dri will be referred to as the outer side Dro of the radial direction Dr. The circumferential direction of the rotating shaft 100 and the tilting pad bearing 1 centered on the axis O will be referred to simply as the circumferential direction Dc.

[0014] A plurality of pads 2 (four in this embodiment) are arranged at intervals in the circumferential direction Dc along the outer circumferential surface 101 of the rotating shaft, which has a circular cross section centered on the axis O. Each pad 2 has a curved cross-sectional shape when viewed from the axial direction Da. All of the pads 2 have the same shape. The pads 2 have a curvature corresponding to the shape of the outer circumferential surface 101 of the rotating shaft. In other words, the pads 2 extend in a curved manner in the circumferential direction Dc along the shape of the outer circumferential surface 101 of the rotating shaft. As shown in FIG. 2 , the pad 2 in this embodiment is supported by a support portion 4 so as to be able to swing relative to the housing 3. The pad 2 has a pad surface 21 and a pad outer circumferential surface 22.

[0015] The pad surface 21 is a surface of the pad 2 facing the inner side Dri in the radial direction Dr. The pad surface 21 is a surface that supports the outer peripheral surface 101 of the rotating shaft that rotates around the axis O so as to be in sliding contact with the pad surface 21. The pad surface 21 faces the outer peripheral surface 101 of the rotating shaft in the radial direction Dr. As shown in FIG. 1 , the pad surface 21 is curved so as to be concave toward the outer side Dro in the radial direction Dr when viewed from the axial direction Da. The radius of curvature of the pad surface 21 is set to be the same as or slightly larger than the radius of curvature of the outer peripheral surface 101 of the rotating shaft. A fluid (lubricating oil or gas) is supplied from a fluid supply unit 5, which will be described later, between the pad surface 21 and the outer peripheral surface 101 of the rotating shaft, and the fluid is present in a film-like state.

[0016] The pad outer peripheral surface 22 is the surface of the pad 2 that faces the outer side Dro in the radial direction Dr. In other words, the pad outer peripheral surface 22 faces the opposite side to the pad surface 21 in the radial direction Dr. When viewed from the axial direction Da, the pad outer peripheral surface 22 is curved so as to be convex toward the outer side Dro in the radial direction Dr. A central portion of the pad outer peripheral surface 22 in the circumferential direction Dc is supported by the support portion 4. As shown in FIG. 2, a pad recess 221 into which a pivot 41, which will be described later, fits is formed in the pad outer peripheral surface 22.

[0017] As shown in FIG. 1, the housing 3 is formed in an annular shape centered on the axis O so as to cover the multiple pads 2. The housing 3 of this embodiment is a cylindrical member that forms an annular shape when viewed from the axial direction Da. The housing 3 is detachably attached to a casing (not shown) of a rotary machine. A pipe (not shown) that sends fluid supplied from an external supply source to the fluid supply unit 5 is connected to the housing 3. As shown in FIG. 2, the housing 3 of this embodiment has a housing inner circumferential surface 31, a housing accommodating recess 32, and a housing discharge flow path 33.

[0018] The housing inner peripheral surface 31 faces the inner side Dri in the radial direction Dr. The housing inner peripheral surface 31 faces the pad outer peripheral surface 22 in the radial direction Dr. The housing inner peripheral surface 31 is disposed with a small gap between it and the pad outer peripheral surface 22. When viewed from the axial direction Da, the housing inner peripheral surface 31 is curved so as to be concave toward the outer side Dro in the radial direction Dr. The radius of curvature of the housing inner peripheral surface 31 is set to be the same as or slightly larger than the radius of curvature of the pad outer peripheral surface 22.

[0019] The housing accommodating recess 32 is capable of accommodating the support part 4. The housing accommodating recess 32 is formed so as to be recessed outward Dro in the radial direction Dr from the housing inner circumferential surface 31. The housing accommodating recess 32 has a first accommodating recess 321 and a second accommodating recess 322.

[0020] The first accommodating recess 321 is recessed in a circular shape from the housing inner circumferential surface 31 toward the outer side Dro in the radial direction Dr. When viewed from the circumferential direction Dc, the first accommodating recess 321 is formed by a recess wall surface 321a facing the axial direction Da and a bottom surface 321b facing the inner side Dri in the radial direction Dr. The second accommodating recess 322 is recessed further from the bottom surface 321b of the first accommodating recess 321 toward the outer side Dro in the radial direction Dr. When viewed from the radial direction Dr, the second accommodating recess 322 is formed in a circular shape that is smaller than the first accommodating recess 321.

[0021] The housing discharge flow path 33 discharges the fluid in the housing accommodating recess 32 to the outside of the housing 3. The housing discharge flow path 33 penetrates the inside of the housing 3 so as to connect the second accommodating recess 322 to the outside of the housing 3. In this embodiment, the housing discharge flow path 33 opens at the second accommodating recess 322. The housing discharge flow path 33 is formed in the second accommodating recess 322 at the outermost position Dro in the radial direction Dr and at the lower end in the vertical direction. Therefore, the fluid accumulated in the second accommodating recess 322 is discharged to the outside of the housing 3 via the housing discharge flow path 33.

[0022] As shown in FIG. 1, the support portion 4 supports the pad 2 so that it can swing relative to the housing 3. When viewed from the circumferential direction Dc, the support portion 4 is disposed between the housing 3 and the pad 2 in the radial direction Dr. A plurality of support portions 4 are disposed at intervals in the circumferential direction Dc so that one support portion 4 is disposed for each pad 2. As shown in FIG. 2, the support portion 4 of this embodiment has a pivot 41, a liner portion 42, a biasing member 43, and a seal member 44.

[0023] The pivot 41 is in contact with the pad outer peripheral surface 22. The pivot 41 is disposed in the first accommodating recess 321 so that a portion of the pivot 41 protrudes toward the pad 2. In this embodiment, the protruding portion of the pivot 41 is fitted into the pad recess 221. The pivot 41 is formed in a cylindrical shape extending in the radial direction Dr. The pivot 41 has a pad support surface 411, a pivot curved surface 412, a pivot side surface 413, and a seal accommodating recess 414.

[0024] The pad support surface 411 is an end surface of the pivot 41 facing the inner side Dri in the radial direction Dr. The pad support surface 411 is a surface that comes into contact with the pad outer peripheral surface 22. The pivot 41 is in surface contact with the pad outer peripheral surface 22 via the pad support surface 411 within the pad recess 221. As shown in FIG. 3 , the pad support surface 411 is formed in an annular shape when viewed from the radial direction Dr.

[0025] As shown in FIG. 2, the pivot curved surface 412 is an end surface of the pivot 41 facing the outer side Dro in the radial direction Dr. In other words, when viewed from the circumferential direction Dc, the pivot curved surface 412 is curved so as to protrude toward the opposite side from the pad support surface 411 in the radial direction Dr. When viewed from the circumferential direction Dc, the pivot curved surface 412 is curved so that the center in the axial direction Da is most convex toward the outer side Dro in the radial direction Dr. The pivot curved surface 412 of this embodiment is formed in a spherical shape. When viewed from the circumferential direction Dc, the center portion (the most protruding portion) of the pivot curved surface 412 is in contact with the liner portion 42.

[0026] The pivot side surface 413 is a surface facing in a direction intersecting the pad support surface 411 and the pivot curved surface 412. The pivot side surface 413 is a curved surface formed in a cylindrical shape and extending in the radial direction Dr. The pivot side surface 413 faces the recess wall surface 321a with a gap therebetween.

[0027] The seal accommodating recess 414 is capable of accommodating the seal member 44. The seal accommodating recess 414 is recessed from the pivot side surface 413. A plurality of seal accommodating recesses 414 (two in this embodiment) are formed and spaced apart in the radial direction Dr. When viewed from the circumferential direction Dc, the seal accommodating recess 414 is recessed in the axial direction Da. Each seal accommodating recess 414 is formed to a size that can accommodate only one seal member 44. As shown in FIG. 3, the seal accommodating recess 414 is formed so as to be continuous around the entire circumference of the pivot side surface 413 in an annular shape when viewed from the radial direction Dr.

[0028] As shown in FIG. 2 , the liner portion 42 is disposed between the housing 3 and the pivot 41. The liner portion 42 is disposed in the second accommodating recess 322 so that a portion of the liner portion 42 protrudes toward the pivot 41. The liner portion 42 is in contact with the pivot curved surface 412. In this embodiment, the liner portion 42 is formed in a disk shape with a central axis extending in the radial direction Dr. The liner portion 42 is formed of a material harder than the pivot 41. The liner portion 42 is formed of, for example, steel or stainless steel. Note that a coating for reducing friction may be applied to the outer surface of the liner portion 42. The liner portion 42 has a first liner surface 421, a second liner surface 422, a liner accommodating recess 423, and a liner positioning recess 424.

[0029] The first liner surface 421 is an end surface of the liner portion 42 facing the inner side Dri in the radial direction Dr. The first liner surface 421 is formed in a linear shape when viewed from the axial direction Da or the circumferential direction Dc. The first liner surface 421 of this embodiment is formed in a circular shape when viewed from the radial direction Dr. The first liner surface 421 is in contact with the pivot curved surface 412. The first liner surface 421 of this embodiment is in point contact with the pivot curved surface 412 at a single point when viewed from the axial direction Da or the circumferential direction Dc. Note that the first liner surface 421 is not limited to being in point contact with the pivot curved surface 412, as long as it is in contact with the pivot curved surface 412 at a single point when viewed from the circumferential direction Dc. Therefore, depending on the shape of the pivot curved surface 412, line contact may be possible. Furthermore, the first liner surface 421 of this embodiment is disposed within the first accommodating recess 321 when viewed from the circumferential direction Dc.

[0030] The second liner surface 422 is an end surface of the liner portion 42 facing the outer side Dro in the radial direction Dr. When viewed from the circumferential direction Dc, the second liner surface 422 is a surface facing the opposite side to the first liner surface 421 in the radial direction Dr. When viewed from the axial direction Da or the circumferential direction Dc, the second liner surface 422 is formed in a linear shape. When viewed from the radial direction Dr, the second liner surface 422 of this embodiment is formed in a circular shape. When viewed from the circumferential direction Dc, the second liner surface 422 is disposed within the second accommodating recess 322.

[0031] The liner accommodating recess 423 is capable of accommodating the biasing member 43. The liner accommodating recess 423 is formed by being recessed from the second liner surface 422 in the radial direction Dr. The liner accommodating recess 423 is recessed from the second liner surface 422 in a circular shape.

[0032] The liner positioning recess 424 determines the positioning of the liner portion 42 within the second accommodating recess 322 in the axial direction Da and the circumferential direction Dc. The liner positioning recess 424 of this embodiment is insertable into the positioning protrusion 34 formed in the housing 3. The positioning protrusion 34 is formed within the second accommodating recess 322. As shown in FIG. 4 , the positioning protrusion 34 protrudes from the inner circumferential surface of the second accommodating recess 322 in the axial direction Da. When viewed from the radial direction Dr, the liner positioning recess 424 is recessed into a rectangular shape from the side surface of the liner portion 42. The liner positioning recess 424 is fitted into the positioning protrusion 34 from the radial direction Dr, thereby fixing the liner portion 42 within the second accommodating recess 322 in the axial direction Da and the circumferential direction Dc so that it cannot move in the axial direction Da and the circumferential direction Dc.

[0033] As shown in FIG. 2 , the biasing member 43 biases the liner portion 42 toward the pivot 41 relative to the housing 3. The biasing member 43 is disposed between the liner portion 42 and the housing 3. In this embodiment, the biasing member 43 is disposed within the second accommodating recess 322 and the liner accommodating recess 423. When viewed from the circumferential direction Dc, the biasing member 43 is disposed such that the position where the pivot curved surface 412 and the first liner surface 421 are in contact with each other coincides with a position in the axial direction Da. The biasing member 43 is a disc spring accommodated in the liner accommodating recess 423. The biasing member 43 is disposed in a compressed state by the liner portion 42 and the housing 3, thereby biasing the liner portion 42 toward the inner side Dri in the radial direction Dr relative to the housing 3.

[0034] The seal member 44 seals the gap between the recess wall surface 321a and the pivot side surface 413 that form the housing accommodating recess 32. A pair of seal members 44 are arranged spaced apart in the radial direction Dr. Note that the number of seal members 44 is not limited to one, and two or more may be arranged. When viewed from the circumferential direction Dc, the pair of seal members 44 are arranged in the housing accommodating recess 32 spaced apart in the radial direction Dr so as to sandwich a pivot outer peripheral recess 522 (described later). The pair of seal members 44 are each housed in the seal accommodating recess 414 and fixed to the pivot 41. In this embodiment, the seal member 44 is an O-ring that can be arranged in close contact with the pivot side surface 413. When inserted into the first accommodating recess 321 together with the pivot 41 from the radial direction Dr, the seal member 44 is in sliding contact with the recess wall surface 321a. As a result, the space between the pivot side surface 413 and the recess wall surface 321a, sandwiched between the pair of seal members 44 in the radial direction Dr, is sealed.

[0035] The fluid supply unit 5 is capable of supplying fluid to the pad surface 21 from outside the housing 3. The fluid supply unit 5 supplies lubricating oil or gas as the fluid. The fluid supply unit 5 supplies fluid from outside to the pad surface 21 when starting and stopping the rotating shaft 100 to start rotating from a completely stopped state (such as when the rotating machine starts operating) or when the rotating machine is operating at rated speed and the rotating shaft 100 continues to rotate at high speed. The fluid supply unit 5 of this embodiment has a pad flow path 51, a pivot flow path 52, and a housing flow path 53.

[0036] The pad flow path 51 is formed in the pad 2 so as to open at the pad surface 21. The pad flow path 51 sends the supplied fluid through the inside of the pad 2 to the pad surface 21. In this embodiment, the pad flow path 51 extends from the pad outer peripheral surface 22 to the pad surface 21 so as to penetrate the pad 2 in the radial direction Dr. The pad flow path 51 extends so as to bend within the pad 2. A plurality of pad flow paths 51 (for example, four) are arranged at equal intervals per pad 2. When viewed from the circumferential direction Dc, the pad flow path 51 opens at the pad surface 21 at a position where the position where the pivot curved surface 412 and the first liner surface 421 contact each other coincides with the position in the axial direction Da.

[0037] The pivot flow path 52 is formed in the pivot 41 so as to communicate with the pad flow path 51. The pivot flow path 52 sends the supplied fluid through the inside of the pivot 41 to the pad support surface 411. In this embodiment, the pivot flow path 52 extends from the pivot side surface 413 to the pad support surface 411 so as to penetrate the pivot 41. The pivot flow path 52 has a pivot recess 521, a pivot outer periphery recess 522, and a pivot internal flow path 523.

[0038] As shown in FIGS. 2 and 3 , the pivot recess 521 is recessed from the pad support surface 411 in the radial direction Dr. The pivot recess 521 is disposed with the pad support surface 411 in contact with the pad outer peripheral surface 22, thereby communicating with the pad flow path 51. The pivot recess 521 of this embodiment is recessed from the pad support surface 411 in an annular shape when viewed from the radial direction Dr. Specifically, the pivot recess 521 is formed in an annular shape so that, when viewed from the circumferential direction Dc, a position where the contact position between the pivot curved surface 412 and the first liner surface 421 overlaps with a position in the axial direction Da does not become recessed. The pivot recess 521 is formed so that, when viewed from the circumferential direction Dc, a position where the pad flow path 51 opening at the pad outer peripheral surface 22 overlaps with the contact position between the pad support surface 411 and the pad outer peripheral surface 22 becomes recessed.

[0039] The pivot outer periphery recesses 522 are recessed from the pivot side surface 413. In this embodiment, the pivot outer periphery recesses 522 are formed with a gap between each pair of the pivot outer periphery recesses 522. When viewed from the circumferential direction Dc, the pivot outer periphery recesses 522 are formed at positions that overlap with positions where the openings of the pivot internal flow paths 523 are formed on the pivot side surface 413. The pivot outer periphery recesses 522 are connected around the entire circumference of the pivot side surface 413. When viewed from the radial direction Dr, the pivot outer periphery recesses 522 are formed so as to be continuous around the entire circumference of the pivot side surface 413 in an annular shape.

[0040] The pivot internal flow path 523 is formed in the pivot 41 so as to communicate between the pivot recess 521 and the pivot side surface 413. In this embodiment, the pivot internal flow path 523 communicates between the pivot recess 521 and the pivot outer peripheral recess 522. The pivot internal flow path 523 opens at multiple locations (for example, two locations) in the pivot recess 521. The pivot internal flow path 523 opens at multiple locations (for example, two locations) in the pivot outer peripheral recess 522. The pivot internal flow path 523 is formed so as to penetrate through the pivot 41 from the pivot recess 521 to the pivot outer peripheral recess 522.

[0041] The housing flow path 53 is formed in the housing 3 so as to communicate with the pivot flow path 52. The housing flow path 53 sends fluid supplied via an external piping through the inside of the housing 3 to the recess wall surface 321a. In other words, the housing flow path 53 supplies the fluid toward the pivot side surface 413. When viewed from the circumferential direction Dc, the housing flow path 53 of this embodiment opens to the recess wall surface 321a at a position in the radial direction Dr that overlaps with the pivot outer periphery recess 522. In other words, the opening of the housing flow path 53 in the recess wall surface 321a is formed at a position facing the pivot outer periphery recess 522.

[0042] (Action and effect) In the tilting pad bearing 1 configured as described above, the pivot curved surface 412, which curves so as to protrude in the radial direction Dr, is in contact with the first liner surface 421, which is linear when viewed from the axial direction Da and the circumferential direction Dc. As a result, the pivot 41 swings relative to the liner portion 42 fixed to the housing 3. In other words, the pivot 41 swings relative to the housing 3. Therefore, the pad 2, which is supported by the pivot 41 with the pad outer peripheral surface 22 in contact with the pad support surface 411, also swings relative to the housing 3. Therefore, the pad 2 can be supported so as to be swingable relative to the housing 3.

[0043] If the liner portion 42 were not provided and the pivot 41 were directly biased by the biasing member 43, the pivot 41 would not be able to be supported to be able to swing relative to the housing 3. As a result, the pad 2 would not be able to swing relative to the housing 3. In contrast, by providing the liner portion 42 between the biasing member 43 and the pivot 41, the pivot 41 can be biased and allowed to swing.

[0044] Furthermore, the liner portion 42 is urged toward the inner side Dri in the radial direction Dr relative to the housing 3 by the urging member 43. As a result, the pivot 41, which is in contact with the liner portion 42, is also pressed toward the inner side Dri in the radial direction Dr. As a result, the pad outer peripheral surface 22 is pressed toward the inner side Dri in the radial direction Dr by the pad support surface 411. As a result, the pad 2 is pressed toward the rotating shaft 100 so that the pad surface 21 approaches the outer peripheral surface 101 of the rotating shaft. This makes it possible to reduce the gap between the pad surface 21 and the outer peripheral surface 101 of the rotating shaft. This increases the rigidity of the bearing, improves the stability of the rotating shaft 100, and reduces shaft vibration. Therefore, a structure for urging the pad 2 toward the rotating shaft 100 can be obtained with a simple structure.

[0045] Furthermore, a fluid such as lubricating oil or gas supplied from outside the housing 3 is supplied to the pad surface 21 by the fluid supply unit 5. Therefore, a fluid is present between the pad surface 21 and the outer peripheral surface 101 of the rotating shaft when the engine is started or stopped. Therefore, compared to the state before the fluid is supplied, the pad surface 21 is spaced further outward in the radial direction Dr from the outer peripheral surface 101 of the rotating shaft by the amount of fluid present. As a result, direct contact between the pad surface 21 and the outer peripheral surface 101 of the rotating shaft is reduced, thereby reducing wear and damage to the pad 2 and the rotating shaft 100 due to contact between the pad surface 21 and the outer peripheral surface 101 of the rotating shaft. Therefore, a simple structure can be obtained that allows a fluid to be supplied to the pad 2. In this way, the tilting pad bearing 1 described above can simultaneously provide a structure that allows a fluid to be supplied to the pad 2 and a structure that biases the pad 2 toward the rotating shaft 100 with a simple structure.

[0046] Furthermore, the pivot flow passage 52 has a pivot recess 521 recessed from the pad support surface 411 and an internal pivot flow passage 523 formed inside the pivot 41 to connect the pivot recess 521 and the pivot side surface 413. Therefore, the housing flow passage 53 allows the fluid supplied to the pivot side surface 413 to pass through the inside of the pivot 41 and be supplied to the pad support surface 411. Furthermore, the fluid is supplied to the pivot recess 521 recessed from the pad support surface 411, which is in surface contact with the pad outer peripheral surface 22. Therefore, before being supplied to the pad flow passage 51, the fluid fills the pivot recess 521 without leaking between the pad outer peripheral surface 22 and the pad support surface 411. As a result, the fluid is continuously supplied to the pad flow passage 51 at a stable pressure. This allows the fluid to be continuously and stably supplied between the pad surface 21 and the outer peripheral surface 101 of the rotating shaft.

[0047] In addition, the pair of seal members 44 are arranged to sandwich the pivot outer peripheral recess 522 formed at a position overlapping the opening of the pivot internal passage 523 in the pivot side surface 413. Therefore, the fluid supplied from the housing passage 53 is sent to a space sealed by the pair of seal members 44. This prevents the fluid supplied from the housing passage 53 from filling around the pad support surface 411, the pivot curved surface 412, the liner portion 42, and the biasing member 43 in the housing accommodating recess 32. This prevents the fluid supplied from the housing passage 53 from shifting the positional relationship between the pivot 41, the liner portion 42, and the biasing member 43. Therefore, the pad 2 can be stably supported relative to the housing 3.

[0048] Furthermore, by forming the housing discharge flow path 33, even if a small amount of fluid leaks beyond the pair of seal members 44, the leaked fluid can be discharged to the outside of the housing 3. In other words, it is possible to make it even more difficult for fluid to accumulate inside the housing accommodating recess 32. This further prevents the positional relationship between the liner portion 42 and the biasing member 43 from becoming misaligned.

[0049] Furthermore, since the biasing member 43 is housed in the liner accommodating recess 423, it is possible to prevent the biasing member 43 from falling off from the liner portion 42. Therefore, it is possible to continue to hold the biasing member 43 in a stable position between the liner portion 42 and the housing 3. Therefore, it is possible for the biasing member 43 to continue to bias the pivot 41 in a stable state.

[0050] Furthermore, the biasing member 43 is a disc spring, which allows the biasing member 43 to be formed thin in the radial direction Dr, resulting in a simpler structure.

[0051] Furthermore, the liner positioning recess 424 can be inserted into the positioning protrusion 34 formed on the housing 3, so that the liner portion 42 cannot move in the axial direction Da and the circumferential direction Dc within the second accommodating recess 322. This makes it possible to prevent the liner portion 42 from rotating or tilting within the second accommodating recess 322.

[0052] Second Embodiment Next, a second embodiment of a tilting pad bearing according to the present disclosure will be described. In the second embodiment described below, components common to the first embodiment will be denoted by the same reference numerals in the drawings, and descriptions thereof will be omitted.

[0053] 5, in the tilting pad bearing 1A of the second embodiment, the biasing member 43A is a spring washer accommodated in the liner accommodating recess 423. The spring washer is formed so as to have a shorter length in the radial direction Dr than the disc spring of the first embodiment. Therefore, the second accommodating recess 322 is formed deeper in the radial direction Dr than in the first embodiment.

[0054] In this way, by using a spring washer as the biasing member 43A, the spring force and rigidity are increased compared to when a single disc spring is used as the biasing member 43. As a result, it is possible to increase the force that biases the liner portion 42 against the housing 3 while increasing the strength of the biasing member 43A. Furthermore, by using a spring washer, it is easier to arrange a member that biases the liner portion 42 toward the inner side Dri in the radial direction Dr relative to the housing 3 than a disc spring.

[0055] Third Embodiment Next, a third embodiment of a tilting pad bearing according to the present disclosure will be described. In the third embodiment described below, components common to the first and second embodiments will be denoted by the same reference numerals in the drawings, and descriptions thereof will be omitted.

[0056] 6, in the tilting pad bearing 1B of the third embodiment, the biasing member 43B is a plurality of (three in this embodiment) disc springs housed in the liner housing recess 423. In other words, a plurality of the biasing members 43 of the first embodiment is arranged. The plurality of disc springs are arranged so as to repel each other.

[0057] In this way, using multiple disc springs as biasing member 43B can also increase the spring force and rigidity compared to a single disc spring. Furthermore, since biasing member 43B is made up of multiple disc springs, the spring force and rigidity can be adjusted by changing the number of disc springs.

[0058] (Other embodiments) The above describes in detail the embodiments of the present disclosure with reference to the drawings, but the specific configuration is not limited to this embodiment, and design changes and the like are also included within the scope that does not deviate from the gist of the present disclosure.

[0059] The number of pads 2 in the tilting pad bearings 1, 1A, and 1B is not limited to four as in this embodiment. The number of pads 2 may be three or less, or five or more. In this case, the support parts 4 only need to be arranged to correspond to each pad 2.

[0060] Furthermore, the structure of the pad 2 is not limited to that of the present embodiment. The pad 2 may have a different structure or shape depending on the structure of the rotating shaft 100 that it supports and the structure of the support part 4, as long as it has the pad surface 21 and the pad outer peripheral surface 22.

[0061] Furthermore, the structure of the housing 3 is not limited to the structure of this embodiment. For example, the housing accommodating recess 32 does not have to have the first accommodating recess 321 and the second accommodating recess 322.

[0062] Furthermore, the structure of the support portion 4 is not limited to the structure of this embodiment. For example, the shapes of the pivot 41 and the liner portion 42 may be different from those of this embodiment.

[0063] In this embodiment, the support parts 4 have the same structure for all the pads 2, but this is not a requirement. For example, only the support parts 4 corresponding to the pads 2 arranged vertically above the axis O with respect to the rotation shaft 100 may have the biasing member 43.

[0064] Furthermore, the shape and configuration of the fluid supply unit 5 are not limited to those of this embodiment as long as it is capable of supplying fluid to the pad surface 21 from outside the housing 3. Therefore, the shapes of the pad flow path 51, the pivot flow path 52, and the housing flow path 53 may be changed as appropriate.

[0065] Furthermore, unlike this embodiment, the tilting pad bearing 1 is not limited to having the seal member 44. Depending on the structure of the support part 4 and the fluid supply part 5, the tilting pad bearing 1 may not have the seal member 44.

[0066] <Additional Notes> The tilting pad bearings 1, 1A, and 1B described in the embodiments can be understood, for example, as follows.

[0067] (1) A tilting pad bearing 1, 1A, 1B according to a first aspect includes: a plurality of pads 2 each having a pad surface 21 that slidably supports an outer peripheral surface 101 of a rotating shaft that rotates about an axis O; a housing 3 formed in an annular shape about the axis O so as to cover the plurality of pads 2; a support portion 4 that is arranged between the housing 3 and the pads 2 in a radial direction Dr based on the axis O and supports the pads 2 so as to be swingable relative to the housing 3; and a fluid supply portion 5 that supplies fluid to the pad surface 21 from outside the housing 3; wherein the pads 2 have a pad outer peripheral surface 22 facing the opposite side to the pad surface 21 in the radial direction Dr, the housing 3 has a housing accommodating recess 32 that can accommodate the support portion 4, and the support portion 4 has a pad support surface 411 that contacts the pad outer peripheral surface 22 and a pad support surface 411 that contacts the pad outer peripheral surface 22 and a support portion 411 that contacts the pad outer peripheral surface 22 and a support portion 411 that contacts the pad outer peripheral surface 22 and is swingable relative to the housing 3 in the radial direction Dr. The fluid supply section 5 comprises a pivot 41 having a pivot curved surface 412 that curves so as to protrude toward the side opposite to the pad support surface 411, a liner portion 42 that has a first liner surface 421 that is formed in a straight line and contacts the pivot curved surface 412 when viewed from a circumferential direction Dc centered on the axis O, and is arranged between the housing 3 and the pivot 41, and biasing members 43, 43A, 43B that are arranged between the liner portion 42 and the housing 3 and bias the liner portion 42 toward the pivot 41 relative to the housing 3, and the fluid supply section 5 has a pad flow path 51 formed in the pad 2 so as to open at the pad surface 21, a pivot flow path 52 formed in the pivot 41 so as to communicate with the pad flow path 51, and a housing flow path 53 formed in the housing 3 so as to communicate with the pivot flow path 52.

[0068] In such tilting pad bearings 1, 1A, and 1B, the pivot curved surface 412, which curves so as to protrude in the radial direction Dr, is in contact with the first liner surface 421, which is linear when viewed from the circumferential direction Dc. As a result, the pivot 41 swings relative to the liner portion 42 fixed to the housing 3. In other words, the pivot 41 swings relative to the housing 3. Therefore, the pad 2, which is supported by the pivot 41 with the pad outer peripheral surface 22 in contact with the pad support surface 411, also swings relative to the housing 3. Therefore, the pad 2 can be supported so as to be swingable relative to the housing 3.

[0069] Furthermore, the liner portion 42 is urged in the radial direction Dr relative to the housing 3 by the urging members 43, 43A, and 43B. As a result, the pivot 41, which is in contact with the liner portion 42, is also pressed in the radial direction Dr. This causes the pad outer peripheral surface 22 to be pressed in the radial direction Dr by the pad support surface 411. As a result, the pad 2 is pressed toward the rotating shaft 100 so that the pad surface 21 approaches the outer peripheral surface 101 of the rotating shaft. This makes it possible to reduce the gap between the pad surface 21 and the outer peripheral surface 101 of the rotating shaft. This increases the rigidity of the bearing, improves the stability of the rotating shaft 100, and reduces shaft vibration. Therefore, a structure for urging the pad 2 toward the rotating shaft 100 can be obtained with a simple structure.

[0070] Furthermore, fluid supplied from outside the housing 3 is supplied to the pad surface 21 by the fluid supply unit 5. Therefore, fluid is present between the pad surface 21 and the outer peripheral surface 101 of the rotating shaft during start and stop. Therefore, compared to the state before the fluid is supplied, the pad surface 21 is spaced further outward in the radial direction Dr from the outer peripheral surface 101 of the rotating shaft by the amount of fluid present. As a result, direct contact between the pad surface 21 and the outer peripheral surface 101 of the rotating shaft is reduced, thereby reducing wear and damage to the pad 2 and the rotating shaft 100 due to contact between the pad surface 21 and the outer peripheral surface 101 of the rotating shaft. Therefore, a simple structure can be obtained that allows fluid to be supplied to the pad 2. In this way, the tilting pad bearing 1 described above can simultaneously provide a structure that allows fluid to be supplied to the pad 2 and a structure that biases the pad 2 toward the rotating shaft 100 with a simple structure.

[0071] (2) The tilting pad bearings 1, 1A, 1B according to the second aspect are the tilting pad bearings 1, 1A, 1B of (1), wherein the pivot 41 has a pivot side surface 413 that faces in a direction intersecting the pad support surface 411 and the pivot curved surface 412, the housing flow path 53 supplies the fluid toward the pivot side surface 413, and the pivot flow path 52 has a pivot recess 521 recessed from the pad support surface 411 in the radial direction Dr and communicating with the pad flow path 51, and a pivot internal flow path 523 formed in the pivot 41 so as to communicate between the pivot recess 521 and the pivot side surface 413.

[0072] As a result, the housing flow path 53 allows the fluid supplied to the pivot side surface 413 to pass through the inside of the pivot 41 and be supplied to the pad support surface 411. Furthermore, the fluid is supplied to the pivot recess 521 that is recessed from the pad support surface 411 that is in contact with the pad outer peripheral surface 22. Therefore, before being supplied to the pad flow path 51, the fluid fills the pivot recess 521 without leaking between the pad outer peripheral surface 22 and the pad support surface 411. As a result, the fluid is continuously supplied to the pad flow path 51 at a stable pressure. This allows the fluid to be continuously and stably supplied between the pad surface 21 and the outer peripheral surface 101 of the rotating shaft.

[0073] (3) The tilting pad bearings 1, 1A, 1B according to the third aspect are the tilting pad bearings 1, 1A, 1B of (2), wherein the support portion 4 has a pair of sealing members 44 that seal between the recess wall surface 321a that forms the housing accommodating recess 32 and the pivot side surface 413, and the pair of sealing members 44 are arranged in the housing accommodating recess 32 at a distance in the radial direction Dr so as to sandwich the opening of the pivot internal flow path 523 on the pivot side surface 413 when viewed from the circumferential direction Dc.

[0074] As a result, the fluid supplied from the housing flow path 53 is sent to the space sealed by the pair of seal members 44. This prevents the fluid supplied from the housing flow path 53 from filling up around the pad support surface 411, the pivot curved surface 412, the liner portion 42, and the urging member 43 in the housing accommodating recess 32. This prevents the fluid supplied from the housing flow path 53 from shifting the positional relationship between the pivot 41, the liner portion 42, and the urging member 43. Therefore, the pad 2 can be stably supported relative to the housing 3.

[0075] (4) The tilting pad bearing 1, 1A, 1B according to the fourth aspect is any one of the tilting pad bearings 1, 1A, 1B of (1) to (3), wherein the liner portion 42 has a second liner surface 422 facing the opposite side to the first liner surface 421 in the radial direction Dr, and a liner accommodating recess 423 recessed from the second liner surface 422 in the radial direction Dr and capable of accommodating the biasing members 43, 43A, 43B.

[0076] This prevents the biasing members 43, 43A, and 43B from falling off from the liner portion 42. Therefore, the biasing members 43, 43A, and 43B can be continuously held in a stable position between the liner portion 42 and the housing 3. Therefore, the biasing members 43, 43A, and 43B can continue to bias the pivot 41 in a stable state.

[0077] (5) A tilting pad bearing 1 according to a fifth aspect is the tilting pad bearing 1 of (4), in which the biasing member 43 is a disc spring housed in the liner housing recess 423.

[0078] This allows the biasing member 43 to be formed thin in the radial direction Dr, resulting in a simpler structure.

[0079] (6) A tilting pad bearing 1B according to a sixth aspect is the tilting pad bearing 1 of (5), in which the disc springs are stacked in multiple layers in the radial direction Dr within the liner receiving recess 423.

[0080] In this way, using multiple disc springs as biasing member 43B can also increase the spring force and rigidity compared to a single disc spring. Furthermore, since biasing member 43 is made up of multiple disc springs, the spring force and rigidity can be adjusted by changing the number of disc springs.

[0081] (7) A tilting pad bearing 1A according to a seventh aspect is the tilting pad bearing 1 of (4), in which the biasing member 43A is a spring washer housed in the liner housing recess 423.

[0082] This increases the spring force and rigidity compared to when a single disc spring is used as the biasing member 43. As a result, it is possible to increase the force that biases the liner portion 42 against the housing 3 while increasing the strength of the biasing member 43A. Furthermore, by using a spring washer, it is easier to arrange a member that biases the liner portion 42 toward the inner side Dri in the radial direction Dr against the housing 3 than a disc spring. [Explanation of symbols]

[0083] 1, 1A, 1B...Tilting pad bearing 2...Pad 21...Pad surface 22...Outer surface of pad 221...pad recess 3. Housing 31...Inner surface of housing 32...Housing receiving recess 321...First storage recess 321a...recess wall 321b…Bottom surface 322...Second storage recess 33...Housing discharge passage 34... Positioning protrusion 4...Support part 41...Pivot 411...Pad support surface 412...Pivot curved surface 413...Pivot side 414...Seal receiving recess 42...liner section 421...First liner surface 422...Second liner surface 423...liner receiving recess 424...Liner positioning recess 43, 43A, 43B... biasing members 44...Sealing member 5...Fluid supply section 51...Pad flow path 52...Pivot channel 521...Pivot recess 522...Pivot outer periphery recess 523...Pivot internal flow passage 53...Housing flow passage 100...Rotation axis 101...Outer surface of rotating shaft O…Axis line Da…Axis direction Dr…Radial direction Dri…inside Dro...outside Dc…Circumferential direction

Claims

1. a plurality of pads each having a pad surface that supports an outer peripheral surface of a rotary shaft that rotates about an axis line so as to be in sliding contact with the outer peripheral surface; a housing formed in an annular shape around the axis so as to cover the pads; a support portion disposed between the housing and the pad in a radial direction relative to the axis, the support portion supporting the pad so that the pad can swing relative to the housing; a fluid supply unit that supplies fluid to the pad surface from outside the housing, the pad has a pad outer peripheral surface facing the opposite side to the pad surface in the radial direction, the housing has a housing accommodating recess capable of accommodating the support portion, The support portion is a pivot having a pad support surface that contacts the outer peripheral surface of the pad and a pivot curved surface that curves so as to protrude toward the opposite side of the pad support surface in the radial direction; a liner portion disposed between the housing and the pivot, the liner portion having a first liner surface that is formed linearly when viewed in a circumferential direction about the axis and that contacts the pivot curved surface; a biasing member disposed between the liner portion and the housing and biasing the liner portion toward the pivot relative to the housing, The fluid supply unit a pad flow channel formed in the pad so as to open on the pad surface; a pivot channel formed in the pivot so as to communicate with the pad channel; a housing passage formed in the housing so as to communicate with the pivot passage; the pivot has a pivot side surface facing in a direction intersecting the pad support surface and the pivot curved surface; the housing flow passage supplies the fluid toward the pivot side surface; The pivot channel is a pivot recess recessed from the pad support surface in the radial direction and communicating with the pad flow path; A tilting pad bearing having an internal pivot passage formed in the pivot so as to communicate the pivot recess and the pivot side surface.

2. the support portion has a pair of seal members that seal between a recess wall surface that forms the housing accommodating recess and the pivot side surface, 2. A tilting pad bearing as described in claim 1, wherein the pair of sealing members are arranged in the housing accommodating recess at a distance from each other in the radial direction so as to sandwich the opening of the pivot internal flow path on the pivot side surface when viewed from the circumferential direction.

3. 3. A tilting pad bearing as described in claim 1 or claim 2, wherein the liner portion has a second liner surface facing the opposite side to the first liner surface in the radial direction, and a liner accommodating recess in the radial direction recessed from the second liner surface and capable of accommodating the biasing member.

4. 4. A tilting pad bearing according to claim 3, wherein the biasing member is a disc spring housed in the liner housing recess.

5. The tilting pad bearing according to claim 4 , wherein a plurality of the disc springs are stacked in the radial direction within the liner receiving recess.

6. 4. A tilting pad bearing according to claim 3, wherein the biasing member is a spring washer accommodated in the liner accommodating recess.

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