JP2019078364A - Thrust bearing and turbocharger - Google Patents

Abstract

To provide a thrust bearing which can inhibit a rapid pressure drop of lubrication oil at a downstream side of a land part, and to provide a turbocharger.SOLUTION: A thrust bearing 4 includes slide surfaces 40f, 40r which are brought into slide-contact with a mating member 53 through an oil film and supports an axial thrust load acting on a rotary shaft 50. The slide surfaces 40f, 40r include multiple pad lines L1, L2 disposed in a concentric circular form. The pad lines L1, L2 have pad parts A1, A2. The pad parts A1, A2 include taper parts B1, B2 and land parts C1, C2. In between the pair of pad lines L1, L2 located adjacent to each other in a radial direction, the land part C1 of the pad part A1 of the one pad line L1 and the taper part B2 of the pad part A2 of the other pad line L2 are located adjacent to each other in the radial direction.SELECTED DRAWING: Figure 5

Description

  The present invention relates to a thrust bearing and a turbocharger for supporting an axial thrust load acting on a rotating shaft.

  For example, as shown in Patent Document 1, the sliding surface of the thrust bearing is in sliding contact with the thrust collar via an oil film. A single pad row is disposed on the sliding surface of the thrust bearing. In the pad row, a plurality of pad portions are arranged continuously in the circumferential direction. Each of the plurality of pad portions includes a tapered portion and a land portion. The lubricating oil passes through the pad row from the upstream side to the downstream side. When the lubricating oil passes through the land portion, an oil film having a predetermined load capacity (allowable load) is formed.

International Publication No. 2016/0633340 brochure

  When transitioning from the land portion of the upstream pad portion to the taper portion of the downstream pad portion, the gap width between the thrust bearing and the thrust collar is rapidly expanded. For this reason, the flow path cross-sectional area of lubricating oil is also expanded rapidly. Therefore, when the lubricating oil flows from the land portion to the tapered portion, the pressure of the lubricating oil is rapidly reduced to generate negative pressure. As described above, an oil film having a predetermined load capacity is formed on the land portion. When a negative pressure is generated when the tapered portion flows in, there is a possibility that the lubricating oil for oil film formation may be drawn from the land portion by the negative pressure. For this reason, there is a possibility that the pressure of the oil film on the land portion may be reduced. Then, an object of this invention is to provide the thrust bearing and turbocharger which can suppress the rapid pressure drop of the lubricating oil in the downstream of a land part.

  In order to solve the above problems, the thrust bearing according to the present invention is a thrust bearing provided with a sliding surface in sliding contact with a mating member via an oil film and supporting an axial thrust load acting on a rotating shaft, In the circumferential direction of the sliding surface, the upstream side of the flow direction of the lubricating oil is the upstream side, and the downstream side of the flow direction is the downstream side, and the sliding surface has a plurality of pad rows arranged concentrically. The row has a pad portion having a tapered portion and a land portion connected to the downstream side of the tapered portion, and the pad portion of one of the pad rows is disposed between a pair of the pad rows adjacent in the radial direction. The land portion and the tapered portion of the pad portion of the other pad row are radially adjacent to each other.

  In order to solve the above-mentioned subject, a turbocharger of the present invention is a turbocharger provided with the above-mentioned thrust bearing, and the above-mentioned other party member is a thrust collar arranged at the above-mentioned axis of rotation.

  According to the thrust bearing and the turbocharger of the present invention, the land portion of the pad portion of one pad row and the tapered portion of the pad portion of the other pad row are radially between the pair of pad rows adjacent in the radial direction. Next to each other. For this reason, lubricating oil can be released from the land portion of the pad portion of one pad row to the tapered portion of the pad portion of the other pad row. Therefore, on the downstream side of the land portion of the pad portion of one pad row, it is possible to suppress the rapid pressure drop of the lubricating oil.

It is an axial sectional view of the turbocharger of a first embodiment. It is an enlarged view in the frame II of FIG. It is a penetration front view of a thrust bearing of a first embodiment. It is a perspective view of the same thrust bearing. It is an enlarged view in the circle V of FIG. It is the VI-VI direction sectional drawing of FIG. It is a permeation | transmission front view of the thrust bearing of 2nd embodiment. It is a perspective view of the same thrust bearing. It is an enlarged view in the circle IX of FIG. FIG. 10 is a partial front view of a front bearing side sliding surface of a thrust bearing according to another embodiment.

  Hereinafter, embodiments of a thrust bearing and a turbocharger according to the present invention will be described.

First Embodiment
[Configuration of turbocharger]
First, the configuration of the turbocharger according to the present embodiment will be described. In the following drawings, the front-rear direction corresponds to the "axial direction" of the present invention. FIG. 1 shows an axial sectional view of the turbocharger of the present embodiment. As shown in FIG. 1, the turbocharger 1 according to the present embodiment includes a journal bearing 3, a thrust bearing 4, a rotating portion 5, a bearing housing 90, a compressor housing 91, and a turbine housing 92. .

  Inside the bearing housing 90, oil passages 901a and 901b and bearing accommodating portions 902a and 902b are formed. Lubricating oil is flowing through the oil passages 901a and 901b. As viewed from the front side or the rear side, the bearing accommodating portion 902 a is disposed at the radial center of the bearing housing 90. The bearing accommodating portion 902 b is disposed on the front side of the bearing accommodating portion 902 a.

  The journal bearing 3 has a cylindrical shape. The journal bearing 3 is housed in the bearing housing portion 902a. The thrust bearing 4 is accommodated in the bearing accommodation portion 902b. The thrust bearing 4 will be described in detail later. The compressor housing 91 is disposed on the front side of the bearing housing 90. The turbine housing 92 is disposed on the rear side of the bearing housing 90.

  The rotating unit 5 is rotatable with respect to the bearing housing 90. The rotating unit 5 includes a rotating shaft 50, a compressor impeller 51, a turbine impeller 52, a thrust collar 53, and a color turbo seal ring 54.

  The rotating shaft 50 penetrates the bearing housing 90 in the front-rear direction. The rotating shaft 50 is rotatably supported by the journal bearing 3 from the radially outer side. FIG. 2 shows an enlarged view within the frame II of FIG. As shown in FIG. 2, the thrust collar 53 is disposed on the outer peripheral surface of the rotating shaft 50. The thrust collar 53 includes a cylindrical portion 530 and a pair of front and rear flange portions 531 f and 531 r. The cylindrical portion 530 has a cylindrical shape extending in the front-rear direction. The front flange portion 531 f protrudes radially outward from the front end of the cylindrical portion 530. The shaft-side sliding surface 532f is disposed on the rear surface of the flange portion 531f. The rear flange portion 531 r protrudes outward in the radial direction from the rear end of the cylindrical portion 530. The shaft-side sliding surface 532 r is disposed on the front surface of the flange portion 531 r. The thrust collar 53 is rotatably supported by the thrust bearing 4 from the front-rear direction.

  As shown in FIG. 1, the color turbo seal ring 54 is disposed on the outer peripheral surface of the rotating shaft 50. The color turbo seal ring 54 is disposed on the front side of the thrust collar 53. The compressor impeller 51 is attached to the front end of the rotating shaft 50. The turbine impeller 52 is continuous with the rear end of the rotating shaft 50. That is, the rotating shaft 50 connects the compressor impeller 51 and the turbine impeller 52.

[Configuration of thrust bearing]
Next, the configuration of the thrust bearing of the present embodiment will be described. FIG. 3 shows a transmission front view of the thrust bearing of the present embodiment. FIG. 4 shows a perspective view of the same thrust bearing. The angle shown in FIG. 3 is a central angle around the axial center G of the rotation axis 50. The flow direction upstream side of the lubricating oil in the circumferential direction (the circumferential direction centering on the axial center G) of the bearing side sliding surface 40f is referred to as "upstream side", and the flow direction downstream side is referred to as "downstream side". The central angle advances in the clockwise direction in FIG. 3 from the upstream side to the downstream side, with the directly lower position as 0 °.

  As shown in FIGS. 2 to 4, the thrust bearing 4 is annularly mounted on the radially outer side of the cylindrical portion 530. The thrust bearing 4 is disposed between the front flange portion 531 f and the rear flange portion 531 r. The thrust bearing 4 has a horseshoe shape (C-shape opening downward) when viewed from the front side.

  The thrust bearing 4 includes a sliding portion 40, a non-sliding portion 41, and an oil passage 42. A bearing-side sliding surface 40 f is disposed on the front surface of the sliding portion 40. The bearing side sliding surface 40f is in sliding contact with the front shaft side sliding surface 532f via an oil film. The bearing-side sliding surface 40 r is disposed on the rear surface of the sliding portion 40. The bearing-side sliding surface 40r is in sliding contact with the rear-side shaft-side sliding surface 532r via an oil film. The bearing side sliding surfaces 40f and 40r are included in the concept of the "sliding surface" of the present invention. The bearing side sliding surfaces 40f and 40r will be described in detail later.

  The non-sliding portion 41 is disposed radially outward of the sliding portion 40. The non-sliding portion 41 is not in sliding contact with the thrust collar 53. The oil passage 42 connects the oil passage 901 a of the bearing housing 90 and the bearing side sliding surfaces 40 f and 40 r. The lubricating oil is supplied from the oil passage 901a to the bearing side sliding surfaces 40f and 40r through the oil passage 42.

[Composition of bearing side sliding surface]
Next, the configuration of the bearing-side sliding surface of the thrust bearing of the present embodiment will be described. The configuration of the pair of front and rear bearing side sliding surfaces 40f and 40r is the same. Hereinafter, the configuration of the front bearing side sliding surface 40f will be described as a representative.

  FIG. 5 shows an enlarged view within the circle V of FIG. FIG. 6 shows a cross-sectional view taken along the line VI-VI of FIG. In FIG. 5, dotted line hatching is applied to the tapered portions B1 and B2. As shown in FIG. 5, the bearing-side sliding surface 40f includes an inner circumferential row L1 and an outer circumferential row L2. The inner circumferential row L1 is included in the concept of "the radially inner pad row" in the present invention. The outer circumferential row L2 is included in the concept of "the radially outer pad row" in the present invention. The inner circumferential row L <b> 1 and the outer circumferential row L <b> 2 are arranged concentrically with the axis G as a center. The outer circumferential row L2 is disposed radially outside the inner circumferential row L1.

  The inner circumferential row L1 includes three pad portions A1. The three pad portions A1 are arranged side by side in the circumferential direction. The pad portion A1 includes a tapered portion B1, a land portion C1, and a pressure-rising side boundary portion D1. A step-down boundary portion E1 is disposed at the boundary between a pair of pad portions A1 adjacent in the circumferential direction.

  The tapered portion B1 has a height (in detail, the height in the front-rear direction; the same applies hereinafter) increases from the upstream side (rear side in the rotational direction of the rotary shaft 50) to the downstream side (front side in the rotational direction of the rotary shaft 50). It has a flat shape. An oil passage 42 opens at an upstream portion of the tapered portion B1.

  The land portion C1 is continued to the downstream side of the tapered portion B1. The land portion C1 has a planar shape with a constant height. The pressurizing side boundary portion D1 is disposed between the upstream tapered portion B1 and the downstream land portion C1. The pressurizing side boundary portion D1 has a linear shape extending in the radial direction. The step-down boundary portion E1 is disposed between the land portion C1 on the upstream side and the taper portion B1 on the downstream side. The step-down boundary portion E1 has a linear shape extending in the radial direction.

  The outer circumferential row L2 includes two pad portions A2. The configuration of the pad portion A2 is the same as the configuration of the pad portion A1. That is, the pad portion A2 includes the tapered portion B2, the land portion C2, and the pressure-rising side boundary portion D2. A step-down side boundary portion E2 is disposed at the boundary between a pair of pad portions A2 adjacent in the circumferential direction.

  The land portion C2 of the pad portion A2 of the outer peripheral row L2 and the tapered portion B1 of the pad portion A1 of the inner peripheral row L1 are adjacent in the radial direction. The tapered portion B1 has a circumferential length longer than that of the land portion C2. Therefore, when viewed from the radial direction, the upstream portion and the downstream portion of the tapered portion B1 protrude from the land portion C2 in the circumferential direction. Similarly, the tapered portion B2 of the pad portion A2 of the outer circumferential row L2 and the land portion C1 of the pad portion A1 of the inner circumferential row L1 are adjacent in the radial direction. The tapered portion B2 has a circumferential length longer than that of the land portion C1. Therefore, when viewed from the radial direction, the upstream portion and the downstream portion of the tapered portion B2 protrude from the land portion C1 in the circumferential direction on both sides. The tapered portion B1 and the tapered portion B2 are connected in a zigzag manner.

[Thrust bearing movement]
Next, the movement of the thrust bearing of the present embodiment will be described. When the turbocharger 1 is driven, as shown in FIGS. 2 and 3, the lubricating oil flows into the oil passage 42 through the oil passage 901 a. The outlet of the oil passage 42 is branched and opened to three pad portions A1 of each of the front and rear bearing side sliding surfaces 40f and 40r. The lubricating oil is supplied to the upstream portion of the pad portion A1 (the upstream portion of the tapered portion B1) via the outlet.

  As indicated by an arrow Y1a in FIG. 5, the lubricating oil supplied to the tapered portion B1 flows from the upstream side toward the downstream side of the pad portion A1. As shown in FIG. 6, the lubricating oil flows in the taper portion B1 while raising its altitude. The flow increases the pressure of the lubricating oil. The pressurized lubricating oil flows into the land portion C1 via the pressure-rising side boundary portion D1. The lubricating oil flowing into the land portion C1 flows through the land portion C1. At this time, the lubricating oil forms an oil film of a predetermined pressure. By the oil film, the bearing side sliding surfaces 40f and 40r rotatably support the shaft side sliding surfaces 532f and 532r. The lubricating oil having passed through the land portion C1 flows into the downstream tapered portion B1 via the step-down side boundary portion E1.

  As indicated by the arrow Y2a in FIG. 5, the lubricating oil supplied to the tapered portion B1 and the lubricating oil having passed through the land portion C1 diffuse outward in the radial direction, and flow from the upstream side to the downstream side of the pad portion A2. Do. Similar to the land portion C1 of the pad portion A1, an oil film is formed on the land portion C2 of the pad portion A2. The lubricating oil after the oil film formation is discharged to the outside of the bearing housing 90 through the oil passage 901b shown in FIG.

[Function effect]
Next, the function and effect of the thrust bearing and the turbocharger of the present embodiment will be described. It is assumed that the outer peripheral row L2 shown in FIG. 5 is not arranged (in the case where the pad row is single). In this case, when transitioning from the land portion C1 of the upstream pad portion A1 to the tapered portion B1 of the downstream pad portion A1, the gap width F1 between the bearing-side sliding surface 40f and the shaft-side sliding surface 532f 6) expands rapidly. For this reason, the flow path cross-sectional area of lubricating oil is also expanded rapidly. Therefore, when the lubricating oil flows from the land portion C1 to the tapered portion B1, the pressure of the lubricating oil is rapidly reduced and a negative pressure is generated. Here, an oil film having a predetermined load capacity is formed on the land portion C1. When a negative pressure is generated when the tapered portion B1 flows in, there is a possibility that the lubricating oil for oil film formation may be drawn from the land portion C1 due to the negative pressure. For this reason, there is a possibility that the pressure of the oil film of land C1 may fall.

  In this respect, the outer peripheral row L2 is disposed on the bearing-side sliding surface 40f. That is, a plurality of pad rows, ie, the inner circumferential row L1 and the outer circumferential row L2, are arranged. The tapered portion B2 of the outer circumferential row L2 bypasses the land portion C1 of the inner circumferential row L1, and connects the upstream tapered portion B1 of the inner circumferential row L1 and the downstream tapered portion B1. As shown by arrow Y1a in FIG. 5, in the tapered portion B1 on the upstream side of the inner circumferential row L1, pressurization of the lubricating oil is performed. As indicated by an arrow Y1b in FIG. 5, a part of the lubricating oil flows out from the tapered portion B1 on the upstream side of the inner circumferential row L1 to the tapered portion B2 of the outer circumferential row L2 with pressure increase. On the other hand, at the step-down side boundary portion E1 of the inner circumferential row L1, negative pressure is generated as the flow passage cross-sectional area is rapidly expanded. As shown by the arrow Y2b in FIG. 5, the lubricating oil flows from the tapered portion B2 of the outer circumferential row L2 to the downstream tapered portion B1 of the inner circumferential row L1 to compensate at least a part of the negative pressure. . Accordingly, it is possible to suppress a rapid pressure drop when the lubricating oil flows from the land portion C1 into the tapered portion B1. That is, it is possible to suppress the rapid pressure drop of the lubricating oil on the downstream side of the land portion C1.

  Similarly, the tapered portion B1 of the inner circumferential row L1 bypasses the land portion C2 of the outer circumferential row L2, and communicates the upstream tapered portion B2 of the outer circumferential row L2 with the downstream tapered portion B2. . As indicated by an arrow Y2a in FIG. 5, in the tapered portion B2 on the upstream side of the outer peripheral row L2, pressure increase of the lubricating oil is performed. As indicated by an arrow Y2b in FIG. 5, a part of the lubricating oil flows out from the tapered portion B2 on the upstream side of the outer circumferential row L2 to the tapered portion B1 of the inner circumferential row L1 with pressure increase. On the other hand, at the step-down side boundary portion E2 of the outer peripheral row L2, a negative pressure is generated as the channel cross-sectional area is rapidly expanded. As shown by the arrow Y1b in FIG. 5, the lubricating oil flows from the tapered portion B1 of the inner circumferential row L1 to the downstream tapered portion B2 of the outer circumferential row L2 to compensate at least a part of the negative pressure. . Accordingly, it is possible to suppress a rapid pressure drop when the lubricating oil flows from the land portion C2 to the tapered portion B2. That is, the rapid pressure drop of the lubricating oil on the downstream side of the land portion C2 can be suppressed.

  If the outer peripheral row L2 shown in FIG. 5 is not disposed (if the pad row is single), the centrifugal force accompanying the rotation of the rotary shaft 50 causes the tapered portion B1 of the pad portion A1 of the inner peripheral row L1. The lubricant oil pressurized in the above manner is likely to escape to the non-sliding portion 41 instead of the land portion C1. The lubricant that has escaped does not contribute at all to the support of the shaft side sliding surfaces 532f and 532r (thrust load support). For this reason, the amount of useless lubricating oil will increase.

  In this respect, the outer peripheral row L2 is disposed on the bearing-side sliding surface 40f. That is, a plurality of pad rows, ie, the inner circumferential row L1 and the outer circumferential row L2, are arranged. Therefore, the lubricating oil that has escaped radially outward from the tapered portion B1 of the pad portion A1 of the inner circumferential row L1 can flow into the land portion C2 of the pad portion A2 of the outer circumferential row L2. Therefore, it is possible to reduce the amount of useless lubricating oil that does not contribute to the support of the thrust load. Thus, the amount of lubricating oil supplied from the oil passage 901a of the bearing housing 90 can be reduced.

Second Embodiment
The difference between the thrust bearing and turbocharger of the present embodiment and the thrust bearing and turbocharger of the first embodiment is that the inner circumferential row and the outer circumferential row each have a single pad portion. Here, only the differences will be described.

  FIG. 7 shows a transmission front view of the thrust bearing of the present embodiment. The parts corresponding to those in FIG. 3 are denoted by the same reference numerals. FIG. 8 shows a perspective view of the same thrust bearing. In addition, about the site | part corresponding to FIG. 4, it shows with the same code | symbol. FIG. 9 shows an enlarged view in the circle IX of FIG. The parts corresponding to those in FIG. 5 are denoted by the same reference numerals.

  As shown in FIGS. 7 to 9, a single pad portion A1 is disposed in the inner circumferential row L1. A single pad portion A2 is disposed in the outer circumferential row L2. The tapered portion B2 of the pad portion A2 of the outer circumferential row L2 is disposed upstream of the tapered portion B1 of the pad portion A1 of the inner circumferential row L1. The pressurizing side boundary portion D2 of the pad portion A2 of the outer circumferential row L2 and the upstream end of the tapered portion B1 of the pad portion A1 of the inner circumferential row L1 are disposed at the same position (90 ° position). The upstream portion of the land portion C2 of the pad portion A2 of the outer peripheral row L2 is disposed radially outside the tapered portion B1 of the pad portion A1 of the inner peripheral row L1. The downstream portion of the land portion C2 of the pad portion A2 of the outer circumferential row L2 and the land portion C1 of the pad portion A1 of the inner circumferential row L1 are adjacent in the radial direction. The lands C1 and C2 extend to the downstream end of the bearing-side sliding surface 40f.

  The thrust bearing and the turbocharger according to the present embodiment and the thrust bearing and the turbocharger according to the first embodiment have the same function and effect as to the parts having the same configuration. According to the thrust bearing of this embodiment, the tapered portions B1 and B2 are not disposed downstream of the land portions C1 and C2. For this reason, it is possible to suppress the rapid pressure drop of the lubricating oil on the downstream side of the land portions C1 and C2.

  Further, according to the thrust bearing and the turbocharger of the present embodiment, the tapered portion B1 of the pad portion A1 of the inner circumferential row L1 and the tapered portion B2 of the pad portion A2 of the outer circumferential row L2 have holes formed inside the thrust bearing. Lubricating oil can be supplied via the oil passage 42.

<Others>
The embodiments of the thrust bearing and the turbocharger according to the present invention have been described above. However, the embodiment is not particularly limited to the above embodiment. It is also possible to carry out in various variants and modifications which can be carried out by those skilled in the art.

  FIG. 10 shows a partial front view of the front bearing side sliding surface of the thrust bearing according to another embodiment. The parts corresponding to those in FIG. 5 are denoted by the same reference numerals. As shown in FIG. 10, the embankment portion H is disposed on the bearing-side sliding surface 40f. The embankment portion H connects the land portion C2 of the pad portion A2 of the outer circumferential row L2 and the land portion C1 of the pad portion A1 of the inner circumferential row L1. The height of the front of the embankment part H is the same as the height of the land parts C1 and C2. According to the thrust bearing and the turbocharger of the present embodiment, an oil film can be formed on the embankment portion H in addition to the land portions C1 and C2. For this reason, the thrust load can be supported by the land portions C1 and C2 and the embankment portion H.

  In addition, by adjusting the height of the embankment portion H, it is possible to adjust the amount of flow of lubricating oil between the outer peripheral row L2 and the inner peripheral row L1 (inter-row flow amount; see arrows Y1b and Y2b). That is, by lowering the levee portion H, the inter-row flow amount can be increased. On the contrary, by making the embankment part H high, it is possible to reduce the inter-row flow amount.

  The tapered portions B1 and B2 shown in FIGS. 5 and 6 may have flat portions whose heights are constant (not inclined) in the circumferential direction. The flat portion may be disposed downstream of the step-down side boundaries E1, E2, and the outlet of the oil passage 42 may be opened in the flat portion. The shape of the thrust bearing 4 shown in FIG. 3 is not particularly limited. The thrust bearing 4 may not have a horseshoe shape. For example, the thrust bearing 4 may have an endless annular shape. The position of the outlet of the oil passage 42 and the number of the outlets are not particularly limited. The outlet of the oil passage 42 may open to the inner peripheral surface of the thrust bearing 4. The application of the thrust bearing 4 is not particularly limited. The thrust bearing 4 may be used independently of the turbocharger 1. For example, the thrust bearing 4 may be embodied as a thrust washer.

  1: Turbocharger, 3: Journal bearing, 4: Thrust bearing, 5: Rotating part, 40: Sliding part, 40f: Bearing side sliding surface (sliding surface), 40r: Bearing side sliding surface (sliding surface ), 41: non-sliding portion, 42: oil passage, 50: rotating shaft, 51: compressor impeller, 52: turbine impeller, 53: thrust collar, 54: color turbo seal ring, 90: bearing housing, 91: compressor housing , 92: turbine housing, 530: cylindrical portion, 531f: flange portion, 531r: flange portion, 532f: shaft side sliding surface, 532r: shaft side sliding surface, 901a: oil passage, 901b: oil passage, 902a: bearing Housing part 902b: Bearing housing part, A1: Pad part, A2: Pad part, B1: Tapered part, B2: Tapered part, C1: Land part, C2: Land part, D1: Boost Boundary part D2: Boost side boundary part E1: Step-down side boundary part E2: Step-down side boundary part F1: Clearance width G: Axial center H: Embankment part L1: Inner circumferential row Row), L2: Outer peripheral row (pad row on the radially outer side)

Claims (8)

A thrust bearing having a sliding surface in sliding contact with a mating member via an oil film, and supporting an axial thrust load acting on a rotating shaft,
In the circumferential direction of the sliding surface, the upstream side of the flow direction of the lubricating oil is the upstream side, and the downstream side of the flow direction is the downstream side,
The sliding surface has a plurality of pad rows arranged concentrically,
The pad row has a pad portion having a tapered portion and a land portion connected to the downstream side of the tapered portion,
The land portion of the pad portion of one pad row and the tapered portion of the pad portion of the other pad row are radially adjacent to each other between the pair of pad rows radially adjacent to each other. Thrust bearing characterized by   Between a pair of the pad rows adjacent in the radial direction, the land portion of the pad portion of the pad row on the outer side in the radial direction and the tapered portion of the pad portion of the pad row in the radial direction are the radial direction The thrust bearing according to claim 1 adjacent to.   Between a pair of the pad rows adjacent in the radial direction, the tapered portion of the pad portion of the pad row on the outer side in the radial direction and the land portion of the pad portion in the pad row on the inner side in the radial direction The thrust bearing according to claim 1 or 2, which is adjacent to.   The sliding surface is formed between the land portion of the pad portion of the pad row on the radially outer side and the land of the pad portion of the pad row on the radially inner side between the pair of pad rows adjacent in the radial direction. The thrust bearing according to any one of claims 1 to 3, further comprising:   5. The tapered portion of another pad portion is not continuous in the circumferential direction on the downstream side of the land portion of any pad portion in any of the pad rows. Thrust bearing described in. The pad row has a single pad portion,
The pad portion has a boosting side boundary portion disposed between the tapered portion and the land portion,
The upstream end of the tapered portion of the pad portion of the pad row that is radially inward between the pair of pad rows that are adjacent in the radial direction is the pressure-rising side boundary portion of the pad portion of the pad row that is radially outer The thrust bearing according to claim 5, wherein the thrust bearing is disposed at the same position in the circumferential direction or on the downstream side of the pressure-side boundary. An oil passage for supplying the lubricating oil to the tapered portion of the pad portion of the radially outer pad row;
The thrust bearing according to claim 6, wherein the oil passage passes through at least one of the inside of the thrust bearing and the inner circumferential surface of the thrust bearing. A turbocharger comprising the thrust bearing according to any one of claims 1 to 7, comprising:
The said opposing member is a turbocharger which is a thrust collar arrange | positioned at the said rotating shaft.

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