WO2024053547A1

WO2024053547A1 - Thrust foil bearing, compressor, and refrigeration device

Info

Publication number: WO2024053547A1
Application number: PCT/JP2023/031768
Authority: WO
Inventors: 直陸大森
Original assignee: ダイキン工業株式会社
Priority date: 2022-09-07
Filing date: 2023-08-31
Publication date: 2024-03-14
Also published as: JP2024037603A

Abstract

Provided is a thrust foil bearing (27) in which a first end side (75) has a predetermined angle with respect to a first boundary line (74), or a second end side (87) has a predetermined angle with respect to a second boundary line (86). A first fixation portion (73) of a back foil (70) is fixed to a base plate (60) in a state in which the first fixation portion (73) overlaps with a second fixation portion (85) of a top foil (80) that is supported by another back foil (70) located next to the back foil (70).

Description

Thrust foil bearings, compressors, and refrigeration equipment

The present disclosure relates to a thrust foil bearing, a compressor, and a refrigeration device.

Thrust foil bearings are conventionally known as bearings for high-speed rotating bodies. Patent Document 1 discloses a thrust foil bearing that is arranged to face a thrust collar (thrust disk) provided on a rotating shaft.

In the thrust foil bearing of Patent Document 1, the bearing surface is formed of a flexible thin metal plate (foil) so as to absorb movement of the rotating shaft (axial displacement and inclination of the thrust collar) caused by vibrations and impacts. . Thrust foil bearings have a foil structure below the bearing surface that flexibly supports the bearing surface.

In the thrust foil bearing of Patent Document 1, a plurality of top foil pieces and a plurality of back foil pieces are arranged in an overlapping manner in the circumferential direction. The top foil piece is supported by the back foil piece. Rotation of the thrust collar introduces lubricating fluid between the top foil piece and the thrust collar. This lubricating fluid forms a wedge-shaped fluid lubricating film between the top foil piece and the thrust collar, and the load capacity of the thrust foil bearing is demonstrated.

International Publication No. 2020/171021 Specification

In the thrust foil bearing described in Patent Document 1, each of the top foil piece and the back foil piece is fixed to the base plate in order to prevent them from falling off the base plate. Specifically, the top foil piece is provided with a fixing allowance on the rear edge in the rotational direction of the rotating shaft, and the fixing allowance is fixed to the base plate. A fixing margin is provided on the front edge of the back foil piece in the rotational direction of the rotating shaft, and the fixing margin is fixed to the base plate.

In the thrust foil bearing of Patent Document 1, a gap is formed between the fixing allowance of the top foil piece and the fixing allowance of the back foil piece adjacent to the top foil piece so that they do not interfere with each other. In addition, in order to secure a working space for fixing both fixing allowances, a gap of a certain size is formed between both fixing allowances.

In this way, thrust foil bearings that require a gap between the two fixing allowances have no choice but to reduce the area of the bearing surface that functions as a bearing, and the load capacity of the thrust foil bearing may not be obtained sufficiently. there were.

The purpose of the present disclosure is to improve the load capacity of thrust foil bearings.

The first aspect is a thrust foil bearing disposed facing a thrust disk (36) provided on a rotating shaft (35), and a top foil bearing disposed facing the thrust disk (36). 80), a back foil (70) located on the opposite side of the thrust disk (36) in the top foil (80), and a back foil (70) located on the opposite side of the top foil (80) in the back foil (70). , and an annular base plate (60) that supports the back foil (70).

The back foil (70) has a plurality of back foil pieces (71) arranged along the circumferential direction of the base plate (60). The back foil piece (71) includes a support part (72) that supports the top foil (80), and a support part (72) on the front side of the support part (72) in the rotational direction of the rotation shaft (35). a first fixing margin (73) that is formed continuously with the base plate (60) and is fixed to the base plate (60); and a first end edge (75) that is the front end in the rotational direction of the first fixing margin (73). and a first boundary line (74) formed at the boundary between the support portion (72) and the first fixing margin (73).

The top foil (80) has a plurality of top foil pieces (81) arranged to overlap each of the plurality of back foil pieces (71). The top foil piece (81) includes a main body part (82) supported by the support part (72), and a main body part (82) that is continuous with the main body part (82) on the rear side of the main body part (82) in the rotational direction. a second fixing margin (85) formed and fixed to the base plate (60); a second end edge (87) that is the rear end in the rotational direction of the second fixing margin (85); It includes a second boundary line (86) formed at the boundary between the main body part (82) and the second fixing margin (85).

The first edge (75) has a predetermined angle with respect to the first boundary line (74), or the second edge (87) has a predetermined angle with respect to the second boundary line (86). The first fixing margin (73) of the back foil piece (71) is the top foil piece (81) supported by the other back foil piece (71) located next to the back foil piece (71). is fixed to the base plate (60) while overlapping with the second fixing margin (85).

In the first aspect, the top foil piece (81) is supported by the first fixing margin (73) of the back foil piece (71) and the other back foil piece (71) adjacent to the back foil piece (71). The second fixing margin (85) is fixed to the base plate (60) in a state where they overlap each other. Therefore, the area that does not function as a bearing surface in the thrust foil bearing can be made smaller. As a result, the area that functions as a bearing surface can be enlarged, and the load capacity of the thrust foil bearing can be improved.

In addition, in the first aspect, the first edge (75) has a predetermined angle with respect to the first boundary line (74), or the second edge (87) has a predetermined angle with respect to the second boundary line (86). has a predetermined angle with respect to the Therefore, when fixing the first fixed allowance (73) and the second fixed allowance (85) adjacent to the first fixed allowance (73) by overlapping each other, the first boundary line (74) and the second boundary line ( 86) can be widened. Thereby, the work of fixing the first fixing margin (73) and the second fixing margin (85) to the base plate can be facilitated.

In a second aspect, in the first aspect, when the first end side (75) has a predetermined angle with respect to the first boundary line (74), the first edge of the back foil piece (71) The end edge (75) is along the second boundary line (86) of the top foil piece (81) that is supported by the other back foil piece (71) located next to the back foil piece (71). will be placed.

In the second aspect, the first end side (75) of the back foil piece (71) is a top foil piece (81) supported by another back foil piece (71) adjacent to the back foil piece (71). along the second boundary line (86). Therefore, positioning when the first fixing margin (73) and the second fixing margin (85) adjacent to the first fixing margin (73) are overlapped and fixed can be easily performed. Thereby, the efficiency of fixing the back foil piece (71) and the top foil piece (81) can be improved.

In a third aspect, in the first aspect, when the second end side (87) has a predetermined angle with respect to the second boundary line (86), the second edge of the top foil piece (81) The edge (87) is along the first boundary line (74) of the back foil piece (71) that supports the other top foil piece (81) located next to the top foil piece (81). Placed.

In the third aspect, the second end side (87) of the top foil piece (81) is connected to the back foil piece (71) that supports another top foil piece (81) adjacent to the top foil piece (81). It is arranged along the first boundary line (74). Therefore, positioning when the first fixing margin (73) and the second fixing margin (85) adjacent to the first fixing margin (73) are overlapped and fixed can be easily performed. Thereby, the efficiency of fixing the back foil piece (71) and the top foil piece (81) can be improved.

In a fourth aspect, in any one of the first to third aspects, the second fixing margin (85) of the top foil piece (81) is located next to the top foil piece (81). is fixed to the base plate (60) via the first fixing margin (73) of the back foil piece (71) that supports the top foil piece (81).

In the fourth aspect, the back foil piece (71) and the top foil piece (81) are arranged and fixed to the base plate (60) in the order of the first fixing margin (73) and the second fixing margin (85). Ru. This is the same arrangement order of the base plate, back foil, and top foil, which are the components of the thrust foil bearing. This facilitates assembly of the thrust foil bearing (27).

In a fifth aspect, in any one of the first to fourth aspects, the support portion (72) of the back foil piece (71) has a peak portion (76) when viewed from the radial direction of the rotating shaft (35). ) and valleys (77) are formed alternately.

In the fifth aspect, the support portion (72) is formed with alternating peaks (76) and valleys (77), so it can elastically support the top foil piece (81).

In a sixth aspect, in the fifth aspect, the height of the mountain portion (76) increases toward the front side in the rotation direction.

In the sixth aspect, the height of the peak portion (76) increases toward the front in the rotational direction. Therefore, a wedge-shaped gap can be formed between the thrust disk (36) and the top foil piece (81).

In a seventh aspect, in the fifth aspect, the base plate (60) supports the support part (72) of the back foil piece (71), and the thrust disk as it goes toward the rear side in the rotation direction. (36) including an inclined surface (62) that slopes away from (36);

In the seventh aspect, the base plate (60) has an inclined surface (62). Therefore, a wedge-shaped gap can be formed between the thrust disk (36) and the top foil piece (81).

An eighth aspect is a compressor comprising the rotating shaft (35) having the thrust disk (36) and the thrust foil bearing (27) according to any one of the first to seventh aspects.

In the eighth aspect, a compressor including a thrust foil bearing (27) with improved load capacity can be provided.

A ninth aspect is a refrigeration system including the compressor (20) of the eighth aspect and a refrigerant circuit (1a) through which refrigerant compressed by the compressor (20) flows.

In the ninth aspect, a refrigeration system including a thrust foil bearing (27) with improved load capacity can be provided.

FIG. 1 is a schematic configuration diagram of a refrigeration apparatus according to a first embodiment. FIG. 2 is a schematic longitudinal sectional view showing the overall configuration of the turbo compressor. FIG. 3 is a side view of the thrust foil bearing of the present disclosure. FIG. 4 is a top view showing the thrust foil bearing of the present disclosure. FIG. 5 is a plan view of the back foil piece according to the first embodiment. FIG. 6 is a plan view of the top foil piece according to the first embodiment. FIG. 7 is an explanatory diagram showing how the back foil piece and top foil piece are fixed according to the first embodiment. FIG. 8 is a side view of FIG. 7. FIG. 9 is a diagram corresponding to FIG. 8 according to a modification of the first embodiment. FIG. 10 is a diagram corresponding to FIG. 5 according to the second embodiment. FIG. 11 is a diagram corresponding to FIG. 6 according to the second embodiment. FIG. 12 is a diagram corresponding to FIG. 7 according to the second embodiment. FIG. 13 is a diagram corresponding to FIG. 8 according to the second embodiment. FIG. 14 is a diagram corresponding to FIG. 9 according to the second embodiment. FIG. 15 is a diagram corresponding to FIG. 7 according to the third embodiment. FIG. 16 is a diagram corresponding to FIG. 8 according to the third embodiment. FIG. 17 is a diagram corresponding to FIG. 9 according to the third embodiment.

Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. Note that the present disclosure is not limited to the embodiments shown below, and various changes can be made without departing from the technical idea of the present disclosure. Each drawing is for conceptually explaining the present disclosure, so dimensions, ratios, or numbers may be exaggerated or simplified as necessary for easy understanding.

《Embodiment 1》
The thrust foil bearing of Embodiment 1 will be described with reference to the drawings. The thrust foil bearing (27) of the present disclosure is applied, for example, to a turbo compressor (20) of a refrigeration system (1).

(1) Overview of the refrigeration system The refrigeration system (1) shown in Figure 1 consists of a turbo compressor (hereinafter also referred to as a compressor) (20) and a refrigerant circuit (20) through which refrigerant compressed by the compressor (20) flows. 1a). The refrigerant circuit (1a) is filled with refrigerant. The refrigerant circuit (1a) includes a compressor (20), a radiator (2), a pressure reduction mechanism (3), and an evaporator (4). The pressure reduction mechanism (3) is an expansion valve. The refrigerant circuit (1a) performs a vapor compression type refrigeration cycle.

In the refrigeration cycle, the refrigerant compressed by the compressor (20) radiates heat to the air in the radiator (2). The refrigerant that has radiated heat is depressurized by the pressure reducing mechanism (3) and evaporated in the evaporator (4). The evaporated refrigerant is sucked into the compressor (20).

The refrigeration device (1) is an air conditioning device. The air conditioner may be a cooling-only machine, a heating-only machine, or an air conditioner that switches between cooling and heating. In this case, the air conditioner has a switching mechanism (for example, a four-way switching valve) that switches the refrigerant circulation direction. The refrigeration device (1) may be a water heater, a chiller unit, a cooling device that cools the air inside the refrigerator, or the like. Cooling devices cool the air inside refrigerators, freezers, containers, etc. The expansion mechanism consists of an electronic expansion valve, a temperature-sensitive expansion valve, an expander, or a capillary tube.

(2) Overview of Compressor An overview of the compressor (20) will be explained with reference to FIG. 2. The compressor (20) of this embodiment is a single-stage type having one compression mechanism (50). The compressor (20) includes a casing (21), a motor (30), a rotating shaft (35), and a compression mechanism (50). The casing (21) accommodates the motor (30), the rotating shaft (35), and the compression mechanism (50). The compressor (20) has a bearing that supports the rotating shaft (35). The bearings include a radial bearing (26) and a thrust foil bearing (27).

(2-1) Casing The casing (21) has a body (22), a first closing part (23), and a second closing part (24). The body (22) is formed into a cylindrical shape with both axial ends open. The first closing portion (23) closes an open portion on one end side in the axial direction of the body portion (22). The first closure part (23) includes a housing (25) located at its center. The second closing portion (24) closes the open portion on the other axial end side of the body portion (22).

(2-2) Motor The motor (30) has a stator (31) and a rotor (32). The stator (31) is formed into a cylindrical shape. The stator (31) is fixed to the inner peripheral surface of the body (22) of the casing (21). The rotor (32) is provided inside the stator (31). The operating frequency (rotation speed) of the motor (30) is adjusted by an inverter device. In other words, the compressor (20) is of an inverter type with variable rotation speed. Therefore, the rotation speed of the motor (30) changes between a relatively low rotation speed and a relatively high rotation speed.

(2-3) Rotating shaft The rotating shaft (35) is fixed to the axial center of the rotor (32). The rotating shaft (35) is rotationally driven by the motor (30). The rotating shaft (35) extends along the axial direction of the casing (21).

The rotating shaft (35) has a thrust disk (36). A thrust disk (36) is formed near the compression mechanism (50) on the rotating shaft (35). The thrust disk (36) is a portion of the rotating shaft (35) with an enlarged diameter. The thrust disk (36) is held between a pair of thrust foil bearings (27), which will be described later.

(2-4) Radial Bearing The radial bearing (26) supports the load (radial load) that acts in the radial direction of the rotating shaft (35) among the loads that act on the rotating shaft (35). The compressor (20) of this embodiment has two radial bearings (26). The number and position of radial bearings (26) are merely examples.

One radial bearing (26) is arranged near one end of the rotating shaft (35). The other radial bearing (26) is arranged near the other end of the rotating shaft (35). Each radial bearing (26) is fixed to the body (22) of the casing (21) via a bearing support (28). Each radial bearing (26) rotatably supports the rotating shaft (35).

(2-5) Thrust foil bearing The thrust foil bearing (27) supports the load (thrust load) that acts in the axial direction of the rotating shaft (35) among the loads that act on the rotating shaft (35). The compressor (20) of this embodiment has two thrust foil bearings (27). The number and location of thrust foil bearings (27) is just an example.

The thrust foil bearing (27) is located near one end of the rotating shaft (35) (close to the compression mechanism (50)). The thrust foil bearing (27) is fixed to the center of a bearing support (28) located near one end of the rotating shaft (35). The thrust foil bearing (27) restricts axial movement of the rotating shaft (35).

(2-6) Compression mechanism The compression mechanism (50) is a centrifugal compression mechanism that applies kinetic energy to the fluid by the centrifugal force of the impeller (51) and converts this kinetic energy into pressure. The compression mechanism (50) includes a housing (25) and an impeller (51). The impeller (51) has multiple blades. In the compression mechanism (50), a compression chamber (52) is formed between the housing (25) and the impeller (51). A suction passage (53) for sending fluid (refrigerant) to the compression chamber (52) is formed in the housing (25).

(3) Details of thrust foil bearing The thrust foil bearing (27) will be explained in detail with reference to FIGS. 3 to 8.

As shown in FIG. 3, two thrust foil bearings (27) are provided on both sides of the thrust disk (36). In other words, the compressor (20) has a pair of thrust foil bearings (27). Each of the thrust foil bearings (27) has the same configuration. Each thrust foil bearing (27) is arranged facing the thrust disk (36).

The thrust foil bearing (27) has a top foil (80), a back foil (70), and a base plate (60). The top foil (80) is arranged opposite the thrust disk (36). The back foil (70) is located on the opposite side of the top foil (80) from the thrust disk (36). The base plate (60) is arranged on the back foil (70) opposite the top foil (80).

The back foil (70) is composed of a plurality of back foil pieces (71). The top foil (80) is composed of a plurality of top foil pieces (81). The same number of back foil pieces (71) and top foil pieces (81) of this embodiment are provided. One back foil piece (71) is provided correspondingly to one top foil piece (81). Note that the same number of top foil pieces (81) and back foil pieces (71) may not be provided.

A cylindrical bearing spacer (40) shown by a two-dot chain line in FIG. 3 is sandwiched between the base plate (60) of each of the pair of thrust foil bearings (27). These base plates (60) are connected via a bearing spacer (40) by a fastening bolt (41).

As shown in FIG. 4, a plurality (in this embodiment, three) of through holes (42) for inserting the fastening bolts (41) are formed in the outer peripheral portion of the base plate (60). Note that one of the base plates (60) connected in this way comes into contact with the bearing support (28) by tightening with the fastening bolt (41).

In the following explanation, unless otherwise specified, "axial direction" refers to the direction of the axis of the rotating shaft (35), and "radial direction" refers to the direction of the axis of the rotating shaft (35). , and the "circumferential direction" refers to the circumferential direction with respect to the axis of the rotating shaft (35). The "radially inner side" is the side closer to the axis of the rotating shaft (35), and the "radially outer side" is the side farther from the axis of the rotating shaft (35). The "rotation direction" is the rotation direction of the rotation shaft (35) shown by arrow Q in FIG.

(3-1) Base Plate As shown in FIG. 3, the base plate (60) constitutes the outermost part of the thrust foil bearing (27) in the axial direction. In other words, the base plate (60) is located at the farthest position from the thrust disk (36) in the axial direction in each thrust foil bearing (27).

The base plate (60) is a plate-shaped member made of metal and approximately several mm thick. As shown in FIG. 4, the base plate (60) has an annular shape. The surface of the base plate (60) of this embodiment is a flat surface with no steps.

A plurality of support areas (61) are formed on the surface of the base plate (60) on the thrust disk (36) side. The support region (61) is a portion for supporting the back foil piece (71) and the top foil piece (81) corresponding to the back foil piece (71). The top foil piece (81) is supported by the back foil piece (71), which is supported by the support area (61) of the base plate (60). In other words, the top foil piece (81) is supported by the support area (61) of the base plate (60) via the back foil piece (71). In this embodiment, the base plate (60) is formed with six support regions (61) equally divided in the circumferential direction. Note that all the support regions (61) in this embodiment are formed on one flat surface.

(3-2) Back foil The back foil (70) elastically supports the top foil (80). The back foil (70) is supported by the base plate (60). The back foil (70) of this embodiment is a bump foil formed by press-molding a thin plate into a corrugated plate shape.

As shown in FIG. 4, the back foil (70) has six back foil pieces (71) arranged along the circumferential direction of the base plate (60). The number of back foil pieces (71) is just an example. Each back foil piece (71) is placed on a respective support area (61) of the base plate (60).

The back foil piece (71) is a thin metal plate (foil) with a thickness of several tens of μm to several hundred μm. As shown in FIG. 5, the back foil piece (71) has a support portion (72), a first fixing margin (73), a first boundary line (74), and a first edge (75). .

The support portion (72) is a portion that supports the top foil piece (81). The support portion (72) is formed into a substantially trapezoidal shape by cutting out the apex side of the sector and making each of the inner and outer edges arcuate.

As shown in FIG. 8, the support portion (72) has a plurality of peaks (76) and a plurality of troughs (77). In other words, the support portion (72) is formed in a corrugated plate shape when viewed from the radial direction of the rotating shaft (35). Specifically, the supporting portion (72) has a valley in the normal direction (hereinafter referred to as the first direction) orthogonal to the end side of the supporting portion (72) in the circumferential direction (front side in the rotational direction Q). It is formed by an alternating series of parts (77) and peaks (76). This first direction is also referred to as a direction perpendicular to the ridgeline of the mountain portion (76). Here, one side in the first direction refers to the right side in FIG. 5, and the other side in the first direction refers to the left side in FIG. Note that the "circumferential direction" and the "first direction" are different directions.

As shown in FIG. 8, the valley (77) is a flat surface. The valley (77) faces the base plate (60). The valley (77) can come into contact with the base plate (60). The peak portion (76) is formed in an arch shape that connects adjacent valley portions (77).

In this embodiment, each of the troughs (77) and peaks (76) is formed at approximately the same pitch. As shown in FIG. 8, the height of the crest (76) (the difference in height between the trough (77) and the crest (76)) increases as you move toward the front side in the rotation direction Q of the rotation shaft (35). , increasing in order. In the support part (72) of this embodiment, one side in the circumferential direction (front side in the rotation direction Q) is composed of a peak part (76), and the other side in the circumferential direction (back side in the rotation direction Q) is composed of a valley part (77). Consists of.

The first fixing margin (73) is a part that is fixed to the base plate (60). As shown in FIG. 5, the first fixing allowance (73) is formed at one end of the support portion (72) in the circumferential direction (in the present embodiment, the front side in the rotation direction Q). The first fixing margin (73) is formed continuously with the support portion (72).

The first fixing allowance (73) is formed in a flat band shape extending in the radial direction. In other words, the first fixing allowance (73) is a portion extending further toward one side in the circumferential direction from the end side on one side in the circumferential direction of the support portion (72). The first fixed margin (73) is configured as a flat surface that is flush with the valley (77).

Note that the other end in the circumferential direction (in this embodiment, the rear side in the rotational direction Q) of the support portion (72) is a free end that is not fixed to the base plate (60).

The first boundary line (74) is formed at the boundary between the support portion (72) and the first fixing margin (73). Specifically, the first boundary line (74) is an edge on one side in the circumferential direction of the support portion (72), and an edge on the other side in the circumferential direction of the first fixing margin (73). The first boundary line (74) extends in the radial direction.

The first edge (75) is the edge on one side in the circumferential direction (front side in the rotational direction Q) of the first fixing allowance (73), and the edge on one side in the circumferential direction (front side in the rotational direction Q) of the back foil piece (71). front side).

The first end side (75) of the back foil piece (71) has a predetermined angle on the front side in the rotation direction Q with respect to the first boundary line (74). The first end side (75) and the first boundary line (74) are not arranged in parallel. Therefore, the width (length in the circumferential direction) of the first fixing margin (73) formed between the first end side (75) and the first boundary line (74) is from the inner end in the radial direction to the outer end. It gradually expands towards the

As shown in FIG. 5, a plurality of (two in this embodiment) slits (78) extending in the circumferential direction from the other side to the one side in the circumferential direction are formed in the support portion (72). The slit (78) is formed in an arc shape. The slit (78) extends to the peak (76) adjacent to the first fixing margin (73).

The support portion (72) is divided into a plurality of (three in this embodiment) divided regions (79) in the radial direction by the plurality of slits (78). The three divided regions (79) are each movable in the first direction.

(3-3) Top foil The top foil (80) acts as a bearing surface during operation of the thrust foil bearing (27). The top foil (80) is supported by the back foil (70).

As shown in FIG. 4, the top foil (80) has six top foil pieces (81) arranged along the circumferential direction. The number of top foil pieces (81) is merely an example; each top foil piece (81) is arranged over a corresponding back foil piece (71).

The top foil piece (81) is a thin metal plate (foil) with a thickness of several tens of μm to several hundred μm. As shown in FIG. 6, the top foil piece (81) has a main body (82), a second fixing margin (85), a second boundary line (86), and a second end side (87). .

The main body portion (82) is a portion supported by the corresponding back foil piece (71). The main body portion (82) is formed into a substantially trapezoidal shape by cutting out the fan-shaped apex side and making each of the inner circumferential side and the outer circumferential side arc-shaped. The main body portion (82) includes a supported portion (83) and a raised portion (84).

As shown in FIG. 8, the supported part (83) is supported by the support part (72) of the corresponding back foil piece (71). The supported portion (83) is arranged to rest on the top of the peak (76) in the support portion (72). The supported portion (83) is inclined at an initial inclination angle so as to approach the thrust disk (36) toward one side in the circumferential direction (the front side in the rotational direction Q) (upward in FIG. 8). Here, the initial inclination angle is the inclination angle of the top foil piece (81) with respect to the base plate (60) when the load applied to the thrust foil bearing (27) is zero. The supported portion (83) is provided to be inclined with respect to the support area (61) of the base plate (60).

The rising part (84) connects the supported part (83) and the second fixing margin (85), and also controls the size of the gap formed between the supported part (83) and the thrust disk (36). This is the part for adjusting the brightness. The rising portion (84) is formed on the other end of the supported portion (83) in the circumferential direction (rear side in the rotational direction Q). The upright portion (84) extends in the radial direction and is formed in a band shape. The rising portion (84) is formed in a step-like shape. Specifically, as shown in FIG. 6, the rising portion (84) has a first bent portion (84a) and a second bent portion (84b).

The first bent portion (84a) is a portion located on the other circumferential side of the raised portion (84). The first bent portion (84a) is bent toward the side opposite to the surface of the raised portion (84) that faces the base plate (60). The second bent portion (84b) is a bent portion located on one circumferential side of the upright portion (84). The second bent portion (84b) is bent toward the surface of the raised portion (84) that faces the base plate (60). Note that both the first bent portion (84a) and the second bent portion (84b) are bent at an obtuse angle with respect to the base plate (60).

The second fixing allowance (85) is a part that is fixed to the base plate (60). Specifically, as shown in FIG. 8, the second fixing allowance (85) is attached to the base plate (60) via the first fixing allowance (73) of the back foil piece (71) adjacent to the other side in the circumferential direction. Fixed.

As shown in FIG. 6, the second fixing allowance (85) is formed at the other end of the main body (82) in the circumferential direction (the rear side in the rotational direction Q). Specifically, the second fixing allowance (85) is formed at the other end of the raised portion (84) in the circumferential direction. The second fixing margin (85) is formed continuously with the main body (82).

The second fixing allowance (85) is formed in a flat band shape extending in the radial direction. In other words, the second fixing allowance (85) is a portion that extends from the other end of the main body (82) in the circumferential direction to the other side in the circumferential direction.

Note that the end of the main body (82) on one side in the circumferential direction (the front side in the rotational direction Q) is a free end that is not fixed to the base plate (60).

The second boundary line (86) is formed at the boundary between the main body (82) and the second fixing margin (85). Specifically, the second boundary line (86) is the edge on the other side in the circumferential direction of the rising portion (84) of the main body (82), and is the edge on the other side in the circumferential direction in the second fixing allowance (85). It's on the edge. The second boundary line (86) extends in the radial direction.

The second end side (87) is the end side of the second fixing allowance (85) on the other side in the circumferential direction (the rear side in the rotational direction Q). In the present embodiment, the second end side (87) is the end side of the top foil piece (81) on the other side in the circumferential direction (front side in the rotational direction Q). The second end side (87) is generally parallel to the second boundary line (86). Therefore, the width (circumferential length) of the second fixing allowance (85) formed between the second end side (87) and the second boundary line (86) is from the radially inner end to the outer end. It is generally the same throughout.

(3-4) Fixing the top foil and back foil As shown in FIGS. 7 and 8, the first fixing allowance (73) of the back foil piece (71) is on one side in the circumferential direction of the back foil piece (71). The second fixing margin (85) of the top foil piece (81) supported by the other back foil piece (71) adjacent to the top foil piece (81) is fixed to the base plate (60) in a mutually overlapping state. In other words, the second fixing allowance (85) of the top foil piece (81) is connected via the first fixing allowance (73) of the back foil piece (71) adjacent to the other circumferential side of the top foil piece (81). and fixed to the base plate (60).

In this way, the first fixing allowance (73) of the back foil piece (71) and the second fixing allowance (85) of the top foil piece (81) adjacent to the back foil piece (71) overlap. is fixed to the base plate (60). This makes it possible to reduce the area of the thrust foil bearing (27) that does not function as a bearing surface (the portion where the back foil piece (71) and the top foil piece (81) are fixed). Accordingly, the area of the region functioning as the bearing surface in the thrust foil bearing (27) can be increased, so that the load capacity of the thrust foil bearing (27) can be improved.

In addition, since the first end side (75) of the back foil piece (71) has a predetermined angle on the front side in the rotation direction Q with respect to the first boundary line (74), the first fixing margin (73) and the corresponding When the first fixing margin (73) and the adjacent second fixing margin (85) are overlapped and fixed, the interval between the first boundary line (74) and the second boundary line (86) can be widened. This facilitates the work of fixing the top foil piece (81) and the back foil piece (71) to the base plate (60).

Note that the area (90) where the first fixing allowance (73) and the second fixing allowance (85) overlap (hereinafter referred to as the fixing area) is the top foil piece ( 81) is determined by the second fixed cost (85). Therefore, as shown in FIG. 7, the width of the fixed region (90) of this embodiment is generally the same from the inner end to the outer end in the radial direction.

In this embodiment, the first fixing margin (73) and the second fixing margin (85) are fixed by spot welding to the base plate (60). As shown in FIG. 7, a plurality of fixing parts (in this embodiment, welded parts) (91) are formed in a line in the radial direction in the fixing region (90). Note that the back foil piece (71) and the top foil piece (81) may be fixed to the base plate (60) by means other than spot welding. For example, the back foil piece (71) and the top foil piece (81) may be fixed to the base plate (60) by caulking, riveting, screwing, or the like.

When fixing the top foil piece (81) and the back foil piece (71), as shown in FIG. 8, the first end side (75) of the back foil piece (71) It is arranged along the second boundary line (86) of the top foil piece (81) that is supported by another back foil piece (71) located next to it. In other words, the first edge (75) of the back foil piece (71) is arranged parallel to the second boundary line (86) of the adjacent top foil piece (81).

As a result, when fixing the top foil piece (81) and the back foil piece (71) to the base plate (60), the first end side (75) of the back foil piece (71) is used as a positioning mark to secure the top foil piece. (81) can be placed on top of each other. Specifically, the top foil piece (81) is arranged so that the first edge (75) of the back foil piece (71) and the second boundary line (86) of the top foil piece (81) overlap. Therefore, it is not necessary to provide a positioning mark to the back foil piece (71), and the top foil piece (81) can be easily positioned. Thereby, the efficiency of fixing the top foil piece (81) and the back foil piece (71) can be improved.

(4) Operating behavior of compressor Next, the operating behavior of the compressor (20) will be explained.

When power is supplied to the motor (30), the rotor (32) of the motor (30) rotates. This causes the rotating shaft (35) and the impeller to rotate. As the impeller (51) rotates, refrigerant is sucked into the compression chamber (52) from the suction passageway (53) and compressed. The compressed high-pressure refrigerant is discharged from the compression chamber (52) to the outside via a discharge passage (not shown).

(5) Action of thrust foil bearing Next, the action of the thrust foil bearing (27) will be explained.

As shown in FIG. 2, the thrust foil bearings (27) are provided on both sides of the thrust disk (36). Thereby, movement of the rotating shaft (35) on both sides in the thrust direction can be suppressed.

When the rotating shaft (35) rotates in this state and the thrust disk (36) starts rotating, the thrust disk (36) and the top foil piece (81) rub against each other and the wedge formed between them Ambient fluid is forced into the space of the shape. When the thrust disk (36) reaches a certain rotational speed, a fluid lubricant film is formed between the two. Due to the pressure of this fluid lubricant film, the top foil piece (81) is pressed toward the back foil piece (71), and the thrust disk (36) breaks out of contact with the top foil piece (81) and becomes non-contact. It starts to rotate.

(6) Features (6-1)
Here, the thrust foil bearing (27) is provided with a plurality of pairs (hereinafter referred to as pads) of a top foil piece (81) and a back foil piece (71) that supports the top foil piece (81). It is being In the conventional thrust foil bearing (27), the fixing allowance for the top foil piece (81) and the fixing allowance for the back foil piece (71) are arranged in the space between the pad and another pad adjacent to the pad. , each fixed directly to the base plate (60).

In such a conventional thrust foil bearing (27), the width of the fixing allowance of the top foil piece (81), the width of the fixing allowance of the back foil piece (71), and the width of the fixing allowance of the back foil piece (71) between adjacent pads are A gap of the same size as the tolerance width is required. In the conventional thrust foil bearing (27), it is necessary to provide a region between the pads that does not function as a bearing surface as described above. Therefore, a sufficient area of the region functioning as a bearing surface could not be secured, and the load capacity as a thrust foil bearing was not fully exhibited.

In contrast, in the thrust foil bearing (27) of the present embodiment, the first end side (75) of the back foil piece (71) has a predetermined angle with respect to the first boundary line (74). The first fixing margin (73) of the back foil piece (71) is the first fixing allowance (73) of the top foil piece (81) that is supported by another back foil piece (71) located next to the back foil piece (71). It is fixed to the base plate (60) in a state where it overlaps with the two fixing allowances (85).

By fixing to the base plate (60) with the first fixing margin (73) and the second fixing margin (85) overlapping, it is possible to reduce the area of the region that does not function as a bearing surface. This makes it possible to increase the area of the region that functions as a bearing surface, thereby improving the load capacity of the thrust foil bearing (27).

Furthermore, conventionally, each of the first fixing margin (73) and the second fixing margin (85) was individually fixed to the base plate (60). In contrast, the thrust foil bearing (27) of this embodiment is fixed to the base plate (60) with the first fixing allowance (73) and the second fixing allowance (85) overlapping each other. This reduces the number of fixing points by half, reducing the time required for fixing work and reducing the number of defective products due to failures in fixing work.

In addition, since the first end side (75) has a predetermined angle with respect to the first boundary line (74), the first fixing margin (73) and the second fixing margin (85) are fixed so as to overlap each other. In this case, the distance between the first boundary line (74) and the second boundary line (86) can be increased. This makes it possible to secure a working space for fixing the first fixing margin (73) and the second fixing margin (85) to the base plate (60), thereby facilitating the fixing work.

(6-2)
The first edge (75) of the back foil piece (71) is the second boundary of the top foil piece (81) supported by another back foil piece (71) located next to the back foil piece (71). Placed along line (86).

This facilitates positioning when fixing the first fixing margin (73) and the second fixing margin (85) adjacent to the first fixing margin (73) in an overlapping manner. This improves the efficiency of fixing work.

(6-3)
The second fixing allowance (85) of the top foil piece (81) is the first fixing allowance of the back foil piece (71) that supports another top foil piece (81) located next to the top foil piece (81). (73) and is fixed to the base plate (60).

This makes assembly of the thrust foil bearing (27) easier because the base plate (60), back foil (70), and top foil (80), which are the components of the thrust foil bearing (27), are arranged in the same order. Can be done.

(6-4)
The support portion (72) of the back foil piece (71) is formed with alternating peaks (76) and valleys (77) when viewed from the radial direction of the rotating shaft (35). Thereby, the back foil piece (71) can elastically support the top foil piece (81).

(6-5)
The height of the peak (76) in the support portion (72) of the back foil piece (71) increases toward the front side in the rotation direction Q. Thereby, a wedge-shaped gap can be formed between the thrust disk (36) and the top foil piece (81).

(7) Modifications The above embodiment may be modified as follows. In addition, in the following description, points that are different from the above embodiment will be explained in principle.

As shown in FIG. 9, in this modification, the configurations of the back foil piece (71) and the base plate (60) are changed in the thrust foil bearing (27) of the above embodiment. In the back foil piece (71) of this modification, the plurality of peaks (76) in the support portion (72) are each formed to have the same height.

In the base plate (60) of this modification, each support region (61) is formed with an inclined surface (62) and a flat surface (63) formed continuously with the inclined surface (62). The inclined surface (62) is formed on the rear side of the support region (61) in the rotation direction Q. The height of the inclined surface (62) increases along the rotation direction Q. That is, the height of the inclined surface (62) (height in the axial direction of the rotating shaft (35)) increases toward the front side in the rotating direction Q. In other words, the inclined surface (62) is inclined away from the thrust disk (36) toward the rear side in the rotation direction Q.

The flat surface (63) is formed on the front side in the rotation direction Q in the support region (61). The flat surface (63) is a flat surface that is not inclined in the support region (61). The flat surface (63) continues from the highest position (front end in the rotation direction Q) of the inclined surface (62) to the support area boundary line (64) formed between adjacent support areas (61). It is a surface. The flat surface (63) is a surface that is generally parallel to the back surface of the base plate (60). The flat surface (63) is formed in a band shape extending in the radial direction.

A surface boundary line (65) between the inclined surface (62) and the flat surface (63) is formed along the radial direction of the base plate (60). Further, the support area boundary line (64) is also formed along the radial direction of the base plate (60).

The height of the inclined surface (62) is inclined so as to gradually become lower in the direction perpendicular to the surface boundary line (65). Therefore, a step is formed in a portion where each support area boundary line (64) is formed (between adjacent support areas (61) with each support area boundary line (64) in between).

The back foil piece (71) is placed on the sloped surface (62) and flat surface (63) of the support area (61). This allows a wedge-shaped gap to be formed between the top foil piece (81) and the thrust disk (36).

In the base plate (60) of this modification, a support region boundary line (64) is formed between mutually adjacent support regions (61). The support area boundary line (64) and the first end side (75) of the back foil piece (71) are arranged to overlap. In this way, when assembling the thrust foil bearing (27), the first end (75) of the back foil piece (71) can be overlapped using the support area boundary line (64) of the base plate (60) as a guide. Therefore, the positioning work of the back foil piece (71) can be facilitated.

In addition, as in the above embodiment, the first end side (75) of the back foil piece (71) is arranged along the second boundary line (86) of the adjacent top foil piece (81). Positioning work when fixing the first fixing margin (73) and the second fixing margin (85) in an overlapping manner can be facilitated. Thereby, the efficiency of fixing work can be further improved.

《Embodiment 2》
The thrust foil bearing (27) of Embodiment 2 will be explained. The thrust foil bearing (27) of this embodiment is the thrust foil bearing (27) of Embodiment 1 in which the configurations of the back foil piece (71) and the top foil piece (81) are changed. Here, differences from Embodiment 1 regarding the thrust foil bearing (27) of this embodiment will be explained.

(1) Back foil piece and top foil piece As shown in FIG. 10, the first end side (75) of the back foil piece (71) of this embodiment is generally parallel to the first boundary line (74). Therefore, the width (length in the circumferential direction) of the first fixing margin (73) formed between the first end side (75) and the first boundary line (74) is It is generally the same across the edges.

As shown in FIG. 11, the second end side (87) of the top foil piece (81) of this embodiment has a predetermined angle on the rear side in the rotation direction Q with respect to the second boundary line (86). The second end side (87) and the second boundary line (86) are not arranged in parallel. Therefore, the width (length in the circumferential direction) of the second fixing allowance (85) formed between the second end side (87) and the second boundary line (86) is It gradually widens towards the edge.

As shown in FIGS. 12 and 13, the first fixing allowance (73) of the back foil piece (71) is fixed to the other back foil piece (71) adjacent to one side in the circumferential direction of the back foil piece (71). The second fixing margin (85) of the supported top foil piece (81) is fixed to the base plate (60) in a mutually overlapping state.

As a result, the area that does not function as a bearing surface in the thrust foil bearing (27) (the portion where the back foil piece (71) and the top foil piece (81) are fixed) can be reduced. Accordingly, the area of the region functioning as the bearing surface in the thrust foil bearing (27) can be increased, so that the load capacity of the thrust foil bearing (27) can be improved.

In addition, since the second end side (87) of the top foil piece (81) has a predetermined angle on the rear side of the rotation direction Q with respect to the second boundary line (86), the first fixing allowance (73) and When the first fixing margin (73) and the adjacent second fixing margin (85) are superimposed and fixed, the interval between the first boundary line (74) and the second boundary line (86) can be widened. This facilitates the work of fixing the top foil piece (81) and the back foil piece (71) to the base plate (60). Note that, as shown in FIG. 12, the width of the fixed region (90) of this embodiment is formed so as to gradually increase from the inner end to the outer end in the radial direction.

When fixing the top foil piece (81) and the back foil piece (71), as shown in FIG. 13, the second end side (87) of the top foil piece (81) It is arranged along a first boundary line (74) of a back foil piece (71) that supports another top foil piece (81) located next to it. In other words, the second end side (87) of the top foil piece (81) is arranged parallel to the first boundary line (74) of the adjacent back foil piece (71).

As a result, when fixing the top foil piece (81) and the back foil piece (71) to the base plate (60), the first boundary line (74) of the back foil piece (71) is used as a positioning mark to fix the top foil piece (81) and the back foil piece (71) to the base plate (60). (81) can be placed on top of each other. Specifically, the top foil piece (81) is arranged so that the first boundary line (74) of the back foil piece (71) and the second end side (87) of the top foil piece (81) overlap. Therefore, it is not necessary to provide a positioning mark to the back foil piece (71), and the top foil piece (81) can be easily positioned. Thereby, the efficiency of fixing the top foil piece (81) and the back foil piece (71) can be improved.

(2) Modifications The above embodiment may be modified as follows. In addition, in the following description, points that are different from the above embodiment will be explained in principle.

As shown in FIG. 14, in this modification, in the thrust foil bearing (27) of the above embodiment, the configurations of the back foil piece (71) and the base plate (60) are changed as in the modification of Embodiment 1. It is something. In the back foil piece (71) of this modification, the plurality of peaks (76) in the support portion (72) are each formed to have the same height. In the base plate (60) of this modification, each support region (61) is formed with an inclined surface (62) and a flat surface (63) formed continuously with the inclined surface (62). The configurations of the inclined surface (62) and the flat surface (63) are similar to those of the modified example of the first embodiment.

Also in this modification, as in Embodiment 2, the second end side (87) of the top foil piece (81) is arranged along the first boundary line (74) of the adjacent back foil piece (71). Therefore, positioning work when fixing the first fixing margin (73) and the second fixing margin (85) in an overlapping manner can be facilitated. Thereby, the efficiency of fixing work can be further improved.

《Embodiment 3》
The thrust foil bearing (27) of Embodiment 3 will be explained. The thrust foil bearing (27) of this embodiment is the thrust foil bearing (27) of Embodiment 1 in which the configurations of the back foil piece (71) and the top foil piece (81) are changed. Here, differences from Embodiment 1 regarding the thrust foil bearing (27) of this embodiment will be explained.

(1) Back foil piece and top foil piece The back foil piece (71) of this modification has the same configuration as the back foil piece (71) of the first embodiment. Specifically, the first end side (75) of the back foil piece (71) has a predetermined angle on the front side in the rotation direction Q with respect to the first boundary line (74). The first end side (75) and the first boundary line (74) are not arranged in parallel. Therefore, the width (length in the circumferential direction) of the first fixing margin (73) formed between the first end side (75) and the first boundary line (74) is from the inner end in the radial direction to the outer end. It gradually expands towards the Specifically, the first fixing margin (73) of this embodiment is formed into a fan shape with a small central angle.

The top foil piece (81) of this modification has the same configuration as the top foil piece (81) of the second embodiment. Specifically, the second end side (87) of the top foil piece (81) has a predetermined angle on the rear side in the rotation direction Q with respect to the second boundary line (86). The second end side (87) and the second boundary line (86) are not arranged in parallel. Therefore, the width (length in the circumferential direction) of the second fixing allowance (85) formed between the second end side (87) and the second boundary line (86) is It gradually widens towards the edge. Specifically, the second fixing margin (85) of this embodiment is formed into a fan shape with a small central angle.

As shown in FIGS. 15 and 16, the first fixing allowance (73) of the back foil piece (71) is fixed to the other back foil piece (71) adjacent to one side in the circumferential direction of the back foil piece (71). The second fixing margin (85) of the supported top foil piece (81) is fixed to the base plate (60) in a mutually overlapping state.

In this embodiment, each of the first fixing allowance (73) and the second fixing allowance (85) gradually widens from the inner end to the outer end in the radial direction. Therefore, the fixing region (90) where the first fixing margin (73) and the second fixing margin (85) overlap is formed in a fan shape. The fixing region (90) of this embodiment has the smallest area when the first fixing margin (73) and the second fixing margin (85) are overlapped and fixed to the base plate (60). In other words, in this embodiment, the distance between adjacent pads can be made the narrowest. Thereby, in this embodiment, the area that does not function as a bearing surface can be minimized. Accordingly, a larger area of the region functioning as a bearing surface can be ensured, so that the load capacity as a thrust foil bearing can be further improved.

In addition, in this embodiment, the fixing region (90) is formed in a narrow fan shape with a small central angle, so the fixing portion (91) is provided only on the radially outer side of the fixing region (90). In other words, the fixing portion (91) is not provided on the radially inner side of the fixing region (90). This reduces the number of work steps required to form the fixing portion (91).

Furthermore, as shown in FIG. 16, in this embodiment, the first end side (75) of the back foil piece (71) is arranged along the second boundary line (86) of the adjacent top foil piece (81). At the same time, the second end side (87) of the top foil piece (81) is arranged along the first boundary line (74) of the adjacent back foil piece (71). This makes positioning easier when fixing the first fixing margin (73) and the second fixing margin (85) to the base plate (60) in an overlapping manner. This improves the efficiency of fixing work.

As shown in FIG. 17, in this modification, in the thrust foil bearing (27) of the above embodiment, the configurations of the back foil piece (71) and the base plate (60) are changed as in the modification of Embodiment 1. It is something. In the back foil piece (71) of this modification, the plurality of peaks (76) in the support portion (72) are each formed to have the same height. In the base plate (60) of this modification, each support region (61) is formed with an inclined surface (62) and a flat surface (63) formed continuously with the inclined surface (62). The configurations of the inclined surface (62) and the flat surface (63) are similar to those of the modified example of the first embodiment.

Also in this modification, similarly to Embodiment 3, the first end side (75) of the back foil piece (71) is arranged along the second boundary line (86) of the adjacent top foil piece (81). At the same time, the second end side (87) of the top foil piece (81) is arranged along the first boundary line (74) of the adjacent back foil piece (71). This makes positioning easier when fixing the first fixing margin (73) and the second fixing margin (85) to the base plate (60) in an overlapping manner. This improves the efficiency of fixing work.

《Other embodiments》
The above embodiment may have the following configuration.

The back foil (70) in each of the above embodiments may be other than a corrugated bump foil. Specifically, it may be a spring foil as disclosed in JP-A No. 2004-270904, a back foil as described in JP-A No. 2009-299748, JP-A No. 2017-180685, and the like. Note that the back foil described in the above publication is a foil used for radial bearings, but it can be applied to foils used for thrust foil bearings by developing it into a flat shape and forming it into an annular plate shape. be.

Although the embodiments and modifications have been described above, it will be understood that various changes in form and details can be made without departing from the spirit and scope of the claims. Further, the elements according to the above embodiments, modifications, and other embodiments may be combined or replaced as appropriate.

The descriptions of “first,” “second,” “third,” etc. mentioned above are used to distinguish the words to which these descriptions are given, and even the number and order of the words are limited. It's not something you do.

As explained above, the present disclosure is useful for thrust foil bearings, compressors, and refrigeration equipment.

1 Refrigeration equipment
1a Refrigerant circuit
20 Turbo compressor (compressor)
27 Thrust foil bearing
35 Rotation axis
36 Thrust Disc
60 base plate
62 Slope
70 back foil
71 Back foil piece
72 Support part
73 First fixed fee
74 First boundary line
75 First edge
76 Yamabe
77 Tanibe
80 top foil
81 Top foil piece
82 Main body
85 Second fixed fee
86 Second boundary line
87 Second edge

Claims

A thrust foil bearing arranged opposite to a thrust disk (36) provided on a rotating shaft (35),
a top foil (80) disposed opposite the thrust disk (36);
a back foil (70) located on the opposite side of the thrust disk (36) in the top foil (80);
an annular base plate (60) disposed on the opposite side of the top foil (80) in the back foil (70) and supporting the back foil (70);
The back foil (70) has a plurality of back foil pieces (71) arranged along the circumferential direction of the base plate (60),
The back foil piece (71) is
a support part (72) that supports the top foil (80);
a first fixing allowance (73) formed continuously with the support part (72) on the front side of the support part (72) in the rotational direction of the rotation shaft (35) and fixed to the base plate (60);
a first end side (75) that is the front end side in the rotational direction of the first fixing allowance (73);
a first boundary line (74) formed at the boundary between the support part (72) and the first fixing margin (73);
The top foil (80) has a plurality of top foil pieces (81) arranged to overlap each of the plurality of back foil pieces (71),
The top foil piece (81) is
a main body portion (82) supported by the support portion (72);
a second fixing allowance (85) formed continuously with the main body part (82) on the rear side of the main body part (82) in the rotational direction and fixed to the base plate (60);
a second end side (87) that is the rear end side in the rotational direction of the second fixing allowance (85);
a second boundary line (86) formed at the boundary between the main body portion (82) and the second fixing margin (85);
The first edge (75) has a predetermined angle with respect to the first boundary line (74), or the second edge (87) has a predetermined angle with respect to the second boundary line (86),
The first fixing margin (73) of the back foil piece (71) is the top foil piece (81) supported by the other back foil piece (71) located next to the back foil piece (71). A thrust foil bearing is fixed to the base plate (60) in a state overlapping with the second fixing allowance (85).
When the first end side (75) has a predetermined angle with respect to the first boundary line (74), the first end side (75) of the back foil piece (71) The thrust foil according to claim 1, wherein the thrust foil is arranged along the second boundary line (86) of the top foil piece (81) supported by the other back foil piece (71) located next to the back foil piece (71). bearing.
When the second end side (87) has a predetermined angle with respect to the second boundary line (86), the second end side (87) of the top foil piece (81) The thrust foil bearing according to claim 1, wherein the thrust foil bearing is arranged along the first boundary line (74) of the back foil piece (71) supporting the other said top foil piece (81) located next to the top foil piece (81). .
The second fixing allowance (85) of the top foil piece (81) is the second fixing allowance (85) of the back foil piece (71) that supports the other top foil piece (81) located next to the top foil piece (81). The thrust foil bearing according to any one of claims 1 to 3, wherein the thrust foil bearing is fixed to the base plate (60) via the first fixing allowance (73).
The support portion (72) of the back foil piece (71) has peaks (76) and valleys (77) alternately formed when viewed from the radial direction of the rotating shaft (35). The thrust foil bearing according to any one of.
The thrust foil bearing according to claim 5, wherein the height of the mountain portion (76) increases toward the front side in the rotation direction.
The base plate (60) supports the support portion (72) of the back foil piece (71), and has an inclined surface ( 62) The thrust foil bearing according to claim 5.
the rotating shaft (35) having the thrust disk (36);
A compressor comprising the thrust foil bearing (27) according to any one of claims 1 to 3.
A compressor (20) according to claim 8,
A refrigeration system comprising: a refrigerant circuit (1a) through which refrigerant compressed by the compressor (20) flows.