WO2020059370A1

WO2020059370A1 - Bearing structure and turbocharger

Info

Publication number: WO2020059370A1
Application number: PCT/JP2019/031893
Authority: WO
Inventors: 祐一大東; 朗弘上田; 真一金田; 寛采浦; 久之本井
Original assignee: 株式会社Ihi
Priority date: 2018-09-19
Filing date: 2019-08-13
Publication date: 2020-03-26

Abstract

A bearing structure S according to the present invention comprises: a semi-floating bearing 7 accommodated in a bearing hole 2b; a projection 7i that projects from an outer circumferential surface of the semi-floating bearing 7 and extends in the circumferential direction; an inner circumferential groove 2g that extends in the circumferential direction on an inner circumferential surface of the bearing hole 2b, and in which the projection 7i is positioned; and a regulating pin 23 that faces the projection 7i in the circumferential direction.

Description

Bearing structure and supercharger

The present disclosure relates to a bearing structure and a supercharger. This application claims the benefit of priority based on Japanese Patent Application No. 2018-174644 filed on September 19, 2018, the contents of which are incorporated herein by reference.

セミ A semi-floating bearing may be used for the supercharger, as described in Patent Document 1, for example. One end of the pin is attached to the housing. The other end of the pin is inserted through the outer peripheral surface of the semi-floating bearing. The movement of the shaft in the semi-floating bearing in the axial direction and the rotation direction is restricted by the pin.

JP 2014-15854 A

Semi-floating bearings receive thrust loads. Therefore, depending on the operating conditions of the engine, the surface pressure acting on the contact portion between the semi-floating bearing and the pin may increase.

目的 An object of the present disclosure is to provide a bearing structure and a supercharger capable of suppressing an increase in surface pressure in a portion that restricts axial movement of a semi-floating bearing.

In order to solve the above problem, a bearing structure according to an embodiment of the present disclosure includes a semi-floating bearing housed in a bearing hole, a projecting portion projecting from an outer peripheral surface of the semi-floating bearing, and extending in a circumferential direction, An inner peripheral groove is provided in the hole, extends in the circumferential direction, and has a protruding portion. The regulating portion includes a regulating portion facing the protruding portion in the circumferential direction.

油 It may be provided with an oil supply passage opening to the inner peripheral groove.

備え The semi-floating bearing may include two radial bearing surfaces formed on the inner peripheral surface thereof, and the protrusion may be such that the position of the semi-floating bearing in the central axis direction of the semi-floating bearing is between the two radial bearing surfaces.

スラ A thrust bearing surface formed on the end surface of the semi-floating bearing may be provided.

The bearing hole includes a first bearing hole and a second bearing hole, and an insertion member having the first bearing hole formed therein, a second bearing hole, and a large inner diameter having an inner diameter larger than the second bearing hole and through which the insertion member is inserted. A hole and a stepped surface extending from the inner peripheral surface of the second bearing hole to the inner peripheral surface of the large-diameter hole and separated from the end of the insertion member in the central axis direction of the semi-floating bearing are formed. And a housing, and an inner peripheral groove may be formed between the insertion member and the step surface.

The protruding part may be provided with a through hole that penetrates in the central axis direction of the semi-floating bearing and through which the restricting part is inserted.

ため In order to solve the above problem, a supercharger according to an embodiment of the present disclosure includes the above bearing structure.

According to the present disclosure, it is possible to suppress an increase in surface pressure in a portion that restricts the movement of the semi-floating bearing in the axial direction.

FIG. 1 is a schematic sectional view of the supercharger. FIG. 2 is a diagram in which a dashed line portion of FIG. 1 is extracted. FIG. 3 is a diagram for explaining a semi-floating bearing. FIG. 4 is a diagram for explaining the insertion member. FIG. 5 is a schematic sectional view of a supercharger according to a modification. FIG. 6 is a diagram in which a dashed line portion of FIG. 5 is extracted. FIG. 7 is a diagram illustrating an insertion member according to a modification.

Hereinafter, an embodiment of the present disclosure will be described in detail with reference to the accompanying drawings. The dimensions, materials, other specific numerical values, and the like shown in the embodiments are merely examples for facilitating understanding, and do not limit the present disclosure unless otherwise specified. In the specification and the drawings, elements having substantially the same function and configuration are denoted by the same reference numerals, and redundant description will be omitted. Elements not directly related to the present disclosure are not shown.

FIG. 1 is a schematic sectional view of the supercharger C. Hereinafter, the direction of arrow L shown in FIG. 1 will be described as the left side of the turbocharger C. 1 will be described as the right side of the supercharger C. As shown in FIG. 1, the supercharger C includes a supercharger main body 1. The supercharger main body 1 includes a bearing housing 2 (housing). The turbine housing 4 is connected to the left side of the bearing housing 2 by a fastening mechanism 3. A compressor housing 6 is connected to the right side of the bearing housing 2 by a fastening bolt 5.

突起 A projection 2a is provided on the outer peripheral surface of the bearing housing 2 near the turbine housing 4. The projection 2a projects in the radial direction of the bearing housing 2. A protrusion 4a is provided on the outer peripheral surface of the turbine housing 4 near the bearing housing 2. The projection 4a projects in the radial direction of the turbine housing 4. The

projections

2a, 4a are band-fastened by the fastening mechanism 3. The fastening mechanism 3 is configured by, for example, a G coupling.

軸受 A bearing hole 2b is formed in the bearing housing 2. The bearing hole 2b penetrates the turbocharger C in the left-right direction. The semi-floating bearing 7 is provided in the bearing hole 2b. The shaft 8 is rotatably supported by the semi-floating bearing 7. At the left end of the shaft 8, a turbine impeller 9 is provided. The turbine impeller 9 is rotatably housed in the turbine housing 4. A compressor impeller 10 is provided at the right end of the shaft 8. The compressor impeller 10 is rotatably accommodated in the compressor housing 6.

吸気 An intake port 11 is formed in the compressor housing 6. The intake port 11 opens to the right of the turbocharger C. The intake port 11 is connected to an air cleaner (not shown). When the bearing housing 2 and the compressor housing 6 are connected by the fastening bolts 5, the diffuser flow path 12 is formed by the facing surfaces of the bearing housing 2 and the compressor housing 6. The diffuser channel 12 pressurizes air. The diffuser flow path 12 is formed in a ring shape from the radial inside to the outside of the shaft 8. The inside of the diffuser channel 12 in the radial direction communicates with the intake port 11.

コンプレッサ A compressor scroll flow path 13 is provided in the compressor housing 6. The compressor scroll channel 13 is annular. The compressor scroll passage 13 is located, for example, radially outside the shaft 8 from the diffuser passage 12. The compressor scroll passage 13 communicates with an intake port of an engine (not shown). The compressor scroll channel 13 also communicates with the diffuser channel 12. When the compressor impeller 10 rotates, air is drawn into the compressor housing 6 from the intake port 11. The intake air is accelerated by the action of centrifugal force in the process of flowing between the blades of the compressor impeller 10. The speed-up air is pressurized in the diffuser channel 12 and the compressor scroll channel 13. The pressurized air is led to the intake port of the engine.

吐出 A discharge port 14 is formed in the turbine housing 4. The discharge port 14 opens to the left of the supercharger C. The discharge port 14 is connected to an exhaust gas purification device (not shown). The turbine housing 4 is provided with a channel 15 and a turbine scroll channel 16. The turbine scroll channel 16 is annular. The turbine scroll flow path 16 is located outside the flow path 15 in the radial direction of the turbine impeller 9. The turbine scroll passage 16 communicates with a gas inlet (not shown). Exhaust gas discharged from an exhaust manifold of the engine is guided to the gas inlet. The turbine scroll flow path 16 also communicates with the flow path 15 described above. The exhaust gas guided from the gas inlet to the turbine scroll flow path 16 is guided to the discharge port 14 via the flow path 15 and the turbine impeller 9. The exhaust gas rotates the turbine impeller 9 during the flow.

回転 The rotational force of the turbine impeller 9 is transmitted to the compressor impeller 10 via the shaft 8. As described above, the air is pressurized by the rotational force of the compressor impeller 10 and guided to the intake port of the engine.

FIG. 2 is a diagram in which a dashed line portion of FIG. 1 is extracted. As shown in FIG. 2, a bearing structure S is provided inside the bearing housing 2. The bearing structure S includes an oil supply passage 2c formed in the bearing housing 2. The lubricating oil flows into the bearing hole 2b from outside the bearing housing 2 through the oil supply passage 2c. Thus, the lubricating oil is supplied to the semi-floating bearing 7 provided in the bearing hole 2b.

The semi-floating bearing 7 has an annular main body 7a. The shaft 8 is inserted inside the main body 7a. Two radial bearing surfaces 7b and 7c are formed on the inner peripheral surface of the main body 7a. The radial bearing surfaces 7b and 7c are separated from each other in the axial direction of the shaft 8 (the central axis direction of the main body 7a of the semi-floating bearing 7; hereinafter, simply referred to as the axial direction).

一部 Part of the lubricating oil supplied to the bearing hole 2b flows into the inner peripheral surface of the main body 7a through the oil hole 7d. The oil hole 7d penetrates the main body 7a from the inner peripheral surface to the outer peripheral surface. The oil hole 7d is provided between the radial bearing surface 7b and the radial bearing surface 7c in the main body 7a. The oil hole 7d faces the opening of the oil supply passage 2c formed in the bearing hole 2b. Lubricating oil is supplied to the gap between the shaft 8 and the

radial bearing surfaces

7b, 7c. The shaft 8 is supported by the oil film pressure of the lubricating oil supplied to the gap.

ダン

Damper surfaces

7e and 7f are formed on both ends in the axial direction of the outer peripheral surface of the main body 7a. The diameters of the damper surfaces 7e and 7f are larger than other portions of the main body 7a. A gap is formed between the

damper surfaces

7e, 7f and the inner peripheral surface of the bearing hole 2b. The vibration of the shaft 8 is suppressed by the oil film pressure of the lubricating oil supplied to the gap from the oil supply passage 2c.

油 Further, on the shaft 8, on the right side of the main body 7 a in FIG. 2 (on the side of the compressor impeller 10), an oil draining member 21 is attached. The oil draining member 21 is an annular member. The oil draining member 21 scatters the lubricating oil radially outward. Thus, the oil draining member 21 suppresses the leakage of the lubricating oil to the compressor impeller 10 side.

大 The shaft 8 is provided with a large diameter portion 8a. The outer diameter of the large diameter portion 8a is larger than the inner diameter of the radial bearing surface 7b. The large diameter portion 8a is located on the left side (on the turbine impeller 9 side) in FIG. 2 with respect to the main body portion 7a. The large diameter portion 8a faces the main body 7a in the axial direction.

Thus, the main body portion 7a is sandwiched in the axial direction by the oil draining member 21 and the large diameter portion 8a. Lubricating oil is supplied to the gap between the main body 7a and the oil draining member 21 and the gap between the main body 7a and the large diameter portion 8a. When the shaft 8 moves in the axial direction, the oil draining member 21 or the large diameter portion 8a is supported by the oil film pressure between the oil draining member 21 and the main body 7a.

That is, of the semi-floating bearing 7, the axial end faces are the thrust bearing faces 7g and 7h. The thrust bearing surfaces 7g and 7h face the large diameter portion 8a and the oil drain member 21. The thrust bearing surfaces 7g and 7h receive a thrust load.

FIG. 3 is a diagram for explaining the semi-floating bearing 7. 3 is a diagram in which the semi-floating bearing 7 is extracted from FIG. The lower right diagram of FIG. 3 is a view as viewed from the arrow III of the left diagram of FIG. 3 is a top view of the semi-floating bearing 7. FIG.

突出 As shown in FIG. 3, the main body 7a of the semi-floating bearing 7 is provided with a protrusion 7i. The protrusion 7i is continuous with the outer peripheral surface of the main body 7a. The protrusion 7i protrudes in the radial direction of the shaft 8 from the outer peripheral surface of the main body 7a. The protrusion 7i is formed integrally with the main body 7a. However, the protruding portion 7i formed of a different member from the main body 7a may be attached to the main body 7a.

突出 As shown in the left diagram of FIG. 3, the protrusion 7i has an axial position between the two radial bearing surfaces 7b and 7c. That is, the protruding portion 7i is formed on the outer peripheral surface between the two radial bearing surfaces 7b and 7c in the main body 7a.

突出 As shown in the lower right diagram of FIG. 3, the protrusion 7i extends in the circumferential direction of the main body 7a. One end and the other end of the protrusion 7i in the circumferential direction are separated from each other. One end and the other end in the circumferential direction of the protruding portion 7i face in the circumferential direction. A cutout 7j is formed on the upper side of the protrusion 7i in the lower right view of FIG. The notch 7j is formed between one end and the other end of the protrusion 7i in the circumferential direction. The notch 7j extends from the outer peripheral end of the protruding portion 7i to the outer peripheral surface of the main body 7a, for example, in the vertical direction in the lower right diagram of FIG. The oil hole 7d opens at a position facing the notch 7j. The oil hole 7d is located between one end and the other end of the protrusion 7i in the circumferential direction.

貫通 A through-hole 7k is provided in the protrusion 7i. The through hole 7k is located on the opposite side of the notch 7j across the main body 7a. The through hole 7k passes through the protrusion 7i in the axial direction.

FIG. 4 is a view for explaining the insertion member 22. 4 is a diagram in which the insertion member 22 is extracted from FIG. The right view of FIG. 4 is a view taken in the direction of the arrow IV in the left view of FIG. As shown in FIG. 4, the insertion member 22 has an annular main body 22a. A flange portion 22b is formed on the right side of the main body 22a in the left view of FIG. The outer diameter of the flange 22b is larger than that of the main body 22a.

A notch 22c is formed on the lower side of the flange 22b in the right view of FIG. The insertion member 22, the first bearing hole 2b ₁ is provided. The first bearing hole 2b ₁ penetrates the main body 22a and the flange portion 22b in the axial direction.

The first inner peripheral surface of the bearing hole 2b _1, groove 22d is formed. The inner diameter of the groove 22d is greater than the first inner diameter of the bearing hole 2b _1. The notch 22c is cut out of the groove 22d, so that the groove 22d opens outside the flange 22b. The thrust bearing surface 7h and the end face of the oil draining member 21 are located in the groove 22d. When the lubricating oil is scattered from the oil draining member 21 by centrifugal force, the lubricating oil is discharged downward from the notch 22c.

Returning to FIG. 2, the insertion member 22 is assembled to the bearing housing 2. The bearing hole 2 b includes a first bearing hole 2 b ₁ formed in the insertion member 22 and a second bearing hole ₂ b ₂ formed in the bearing housing 2. The first bearing hole 2b ₁ and the second bearing hole 2b _2, an inner diameter equal approximately. The first bearing hole 2b ₁ and the second bearing hole 2b _2, spaced apart in the axial direction. The first bearing hole 2b ₁ and the second bearing hole 2b _2, the central axis is coincident.

That is, the bearing housing 2, a second bearing hole 2b _2, a large inner diameter hole 2d is provided. Large internal diameter bore 2d is continuous axially oil thrower member 21 side with respect to the second bearing hole 2b _2. Large inner diameter hole 2d is larger inner diameter than the second bearing hole 2b _2. The inner diameter difference between the large inner diameter hole 2d and the second bearing hole 2b _2, stepped surface 2e is formed. Step surface 2e extends from the second inner circumferential surface of the bearing hole 2b _2, the radial direction of the inner peripheral surface to the shaft 8 of the large inner diameter hole 2d.

Of the body 22a of the insertion member 22, the flange portion 22b side (described later wall 2f side, oil thrower member 21 side), the press-fitting part 22a ₁ is formed. In a state before the insertion member 22 is assembled to the bearing housing 2, the outer diameter of the press fit portion 22a ₁ is slightly larger than the inner diameter of the large inner diameter hole 2d. The insertion member 22 is inserted into the large-diameter hole 2d and assembled to the bearing housing 2. Press-fitting portion 22a ₁ is press-fitted into the large inner diameter hole 2d. The flange 22b extends to the radial outside of the shaft 8 from the large bore 2d. The flange portion 22b abuts (abuts) on the wall surface 2f of the bearing housing 2. The wall surface 2f is a surface of the large-diameter hole 2d where the end on the oil draining member 21 side is open.

(4) The axial position of the insertion member 22 is determined by the contact of the flange portion 22b with the wall surface 2f. The flange portion 22b has a function of positioning the insertion member 22.

端 The end 22e of the main body 22a on the side of the step surface 2e is separated from the bottom surface (step surface 2e) of the large bore 2d in the axial direction toward the oil drain member 21 side. A gap is formed between the end 22e and the step surface 2e. The gap between the end 22e and the step surface 2e forms an inner peripheral groove 2g. The inner peripheral groove 2g is formed on the inner peripheral surface of the bearing hole 2b.

The inner circumferential groove 2g extends in the circumferential direction of the shaft 8 (the main body 7a). Oil supply passage 2c includes a large-diameter passage 2c ₁ and a small-diameter passage 2c _2. Large-diameter passage 2c ₁ and a small-diameter passage 2c ₂ is a hole provided in the bearing housing 2. The inner diameter of the small-diameter passage 2c ₂ is smaller than the inner diameter of the large-diameter passage 2c _1. The large-diameter passage 2 c ₁ opens to the outside of the bearing housing 2. The bottom surface of the large-diameter passage 2c _1, to the large inner diameter hole 2d, spaced apart in the radial direction of the shaft 8. That is, the large-diameter passage 2c _1, between the large inner diameter hole 2d, the partition wall portion 2i is formed. The partition 2i is a part of the bearing housing 2. The partition 2i extends in the axial direction. The partition 2i extends circumferentially along the large-diameter hole 2d.

Diameter passage 2c _2, of the bottom surface of the large-diameter passage 2c _1, for example from the central portion, extending to the inner circumferential grooves 2g. The small-diameter passage 2c _2, the inner circumferential groove 2g is communicated with the large-diameter passage 2c _1. Diameter passage 2c _2, of the inner peripheral groove 2g, in FIG. 2, open in the upper position. Diameter passage 2c ₂ faces the partition wall portion 2i.

Here, the case where the partition 2i is provided has been described. However, the partition 2i may not be provided. In this case, large-diameter passage 2c ₁ penetrates the bearing housing 2 to a large inner diameter hole 2d. Insertion member 22 is exposed to the large-diameter passage 2c _1. Lubricating oil from the large-diameter passage 2c _1, the outer peripheral surface of the main body 22a of the insertion member 22, in the gap between the large inner diameter hole 2d, directly arrives.

On the other hand, when the partition 2i is provided, a so-called labyrinth structure is formed by the partition 2i. The lubricating oil of the large-diameter passage 2c ₁ from through the small diameter passage 2c _2, the outer peripheral surface of the main body 22a of the insertion member 22, reaches the gap between the large inner diameter hole 2d. Therefore, the amount of lubricating oil leaking from the oil supply passage 2c to the oil draining member 21 side without passing through the bearing hole 2b is suppressed.

The bearing housing 2 is provided with a positioning hole 2h. The positioning hole 2h extends in the axial direction. The positioning hole 2h opens at a lower portion in FIG. 2 of the step surface 2e.

The semi-floating bearing 7 is assembled to the bearing housing 2 before the insertion member 22. Semi-floating bearing 7 is inserted from the oil thrower member 21 side to the second bearing hole 2b _2. The outer diameter of the protrusion 7i of the semi-floating bearing 7 is smaller than the inner diameter of the large inner diameter hole 2d. The protruding portion 7i is inserted up to the step surface 2e side of the large inner diameter hole 2d.

At this time, the circumferential position of the main body 7a is adjusted such that the through hole 7k faces the positioning hole 2h. The regulating pin 23 (regulating part) is inserted into the through hole 7k and the positioning hole 2h. The restriction pin 23 faces the inner peripheral surface of the through hole 7k in the circumferential direction of the main body 7a. That is, the regulating pin 23 faces the protruding portion 7i in the circumferential direction of the main body 7a. Thus, the movement of the protruding portion 7i (the main body 7a) in the rotation direction of the shaft 8 (the circumferential direction of the main body 7a) is restricted.

Thereafter, the insertion member 22 is inserted into the large-diameter hole 2d. Among the main portion 7a of the semi-floating bearing 7, part of the oil thrower member 21 side than the projecting portion 7i is inserted through the first bearing hole 2b _1.

The protrusion 7i is located between the insertion member 22 and the step surface 2e. That is, the projection 7i is inserted into the inner peripheral groove 2g formed between the bearing housing 2 and the insertion member 22. The protrusion 7i (main body 7a) is restricted from moving in the axial direction. However, the gap between the step surface 2e and the end 22e of the insertion member 22 is larger than the axial thickness of the protrusion 7i. The semi-floating bearing 7 can move slightly in the axial direction. Therefore, the vibration can be absorbed by the damper surfaces 7e and 7f.

As described above, the thrust bearing surfaces 7g and 7h receive a thrust load. The axial movement of the main body 7a in the semi-floating bearing 7 is restricted by the protrusion 7i.

For example, there are cases where a pin or the like is inserted in the semi-floating bearing in the radial direction to restrict the axial movement of the semi-floating bearing. In this case, the surface pressure acting on the contact portion between the semi-floating bearing and the pin increases. In the present embodiment, the movement in the axial direction is restricted by the protrusion 7i. The pressure receiving area receiving the thrust load is larger than that of the pin, and an increase in the surface pressure is suppressed.

FIG. 5 is a schematic sectional view of a supercharger Ca of a modified example. FIG. 6 is a diagram in which a dashed line portion of FIG. 5 is extracted. In the embodiment described above, the case where the thrust bearing surfaces 7g and 7h are formed on the semi-floating bearing 7 has been described. In the modified example, as shown in FIG. 6,

thrust bearings

30 and 31 are provided separately from the semi-floating bearing 7.

The thrust collar 32 has a mounting hole 32a. The shaft 8 is inserted into the mounting hole 32a. The thrust collar 32 is attached to the compressor impeller 10 side of the semi-floating bearing 7 of the shaft 8.

The

thrust bearings

30 and 31 are arranged one by one on both sides in the axial direction with respect to the thrust collar 32. The

thrust bearings

30, 31 receive a thrust load. The thrust bearing 30 has an insertion hole 30a. The insertion hole 30a penetrates the thrust bearing 30 in the axial direction. The thrust bearing 31 has an insertion hole 31a. The insertion hole 31a penetrates the thrust bearing 31 in the axial direction. The shaft 8 is inserted into the

insertion holes

30a and 31a. The shaft 8 and the

thrust bearings

30 and 31 rotate relative to each other.

本体 The main body 42 a of the insertion member 42 is inserted into the large-diameter hole 2 d of the bearing housing 2. The flange 42b of the insertion member 42 contacts the wall surface 2f of the bearing housing 2. The end of the wall surface 2f on the compressor impeller 10 side of the large inner diameter hole 2d is opened. The flange 42b is sandwiched between the wall surface 2f and the thrust bearing 31.

FIG. 7 is a diagram for explaining the insertion member 42 in the modified example. 7 is a diagram in which the insertion member 42 is extracted from FIG. The right view of FIG. 7 is a view on arrow VII of the left view of FIG. As shown in FIG. 7, the main body 42a, similarly to the insertion member 22, the first bearing hole 2b ₁ is provided.

The first of the bearing hole 2b _1, the flange portion 42b side (right side in the left diagram of FIG. 7) has a diameter-enlarged portion 42f. The inner diameter of the enlarged diameter portion 42f is larger than the inner diameter of the main body 42a (left side in the left diagram of FIG. 7). The notch 42c is formed in the flange 42b. The notch 42c also cuts off a part of the main body 42a in addition to the flange 42b. The cutout portion 42c extends to the enlarged diameter portion 42f.

Returning to FIG. 6, the thrust collar 32 and the thrust bearing 30 are housed in the enlarged diameter portion 42f of the insertion member 42. The thrust bearing surface 30b of the thrust bearing 30 and the thrust bearing surface 31b of the thrust bearing 31 communicate with the notch 42c. Lubricating oil to the

thrust bearing

30, 31 has lubricated is discharged from the first bearing hole 2b ₁ through the notch 42c.

油圧 Of the protruding portion 7i, the oil pressure on the

thrust bearings

30 and 31 side is higher than the oil pressure on the side (turbine side) opposite to the

thrust bearings

30 and 31. This is because the flow path of the lubricating oil is narrow at the lubricated portions of the

thrust bearings

30 and 31.

(6) As a result, a thrust load directed to the left side in FIG. When the movement of the semi-floating bearing in the axial direction is restricted by a pin or the like, the surface pressure acting on the contact portion between the semi-floating bearing and the pin increases.

In the modification, similarly to the above-described embodiment, the movement in the axial direction is restricted by the protrusion 7i. The pressure receiving area receiving the thrust load is larger than that of the pin, and an increase in the surface pressure is suppressed.

Although an embodiment of the present disclosure has been described with reference to the accompanying drawings, it is needless to say that the present disclosure is not limited to the above embodiment. It will be apparent to those skilled in the art that various changes or modifications can be made within the scope of the appended claims, and those modifications naturally belong to the technical scope of the present disclosure. Is done.

For example, in the above-described embodiment and modified examples, the case where the oil supply passage 2c is opened in the inner peripheral groove 2g has been described. In this case, when a thrust load occurs, lubricating oil is supplied between the protruding portion 7i and the inner wall surface of the inner peripheral groove 2g. The impact caused by the collision between the protrusion 7i and the inner wall surface of the inner peripheral groove 2g is reduced. However, the oil supply passage 2c may not be opened in the inner circumferential groove 2g.

In the above-described embodiment and the modification, the case where the axial position of the protruding portion 7i is between the two radial bearing surfaces 7b and 7c has been described. In this case, when the semi-floating bearing 7 swings clockwise or counterclockwise in FIGS. 2 and 6, for example, it is possible to reduce the load acting on the protrusion 7i. However, the axial position of the protruding portion 7i may be closer to the turbine impeller 9 than the radial bearing surface 7b, or may be closer to the compressor impeller 10 than the radial bearing surface 7c.

In addition, in the above-described embodiment and modified examples, the case where the

insertion members

22 and 42 that are separate from the bearing housing 2 are provided has been described. In this case, the work of housing the semi-floating bearing 7 in the bearing hole 2b becomes easy. However, as long as the protrusion 7i can be inserted into the inner peripheral groove 2g, the

insertion members

22 and 42 may not be provided.

では In the above-described embodiment and modifications, the through-hole 7k is formed in the protruding portion 7i. The case has been described in which the restriction pin 23 is inserted into the through hole 7k to restrict the movement of the protrusion 7i in the rotation direction. However, if a restricting portion facing the protruding portion 7i in the circumferential direction of the main body portion 7a is provided, the through hole 7k and the restricting pin 23 are not essential components.

For example, the inner peripheral surface of the large-diameter hole 2d may be formed in an elliptical or oval shape. In this case, the outer peripheral surface of the protruding portion 7i is formed in accordance with the inner peripheral surface of the large inner diameter hole 2d. In this way, the movement of the protrusion 7i in the rotation direction may be restricted. In this case, the inner peripheral surface of the large inner diameter hole 2d facing the outer peripheral surface of the protruding portion 7i in the circumferential direction of the main body portion 7a functions as a regulating portion. Further, a cylindrical member may be interposed between the large inner diameter hole 2d and the protruding portion 7i. The outer peripheral surface of the tubular member may be circular. The inner peripheral surface of the tubular member may be elliptical or oval. The outer peripheral surface of the protrusion 7i may be formed in accordance with the inner peripheral surface of the cylindrical member. In this case, the inner peripheral surface of the cylindrical member that opposes the outer peripheral surface of the protruding portion 7i in the circumferential direction of the main body portion 7a functions as a regulating portion. In this case, the cost required for processing the bearing housing 2 can be reduced.

In addition, in the above-described embodiment and the modification, the case where the through-hole 7k and the restriction pin 23 extend in the axial direction has been described. However, the through-hole 7k and the restriction pin 23 may extend in the radial direction of the shaft 8. In this case, for example, a key groove extending in the radial direction of the shaft 8 is provided on both the bearing housing 2 side and the

insertion members

22 and 42 side. The key member is inserted across both key grooves.

In addition, in the above-described embodiment and the modification, the case where the regulating pin 23 is provided separately from the

insertion members

22 and 42 has been described. However, the regulating pin 23 may be formed integrally with the

insertion members

22 and 42.

In addition, in the above-described embodiment and the modified example, the case where the

insertion members

22, 42 are axially positioned by the

flange portions

22b, 42b has been described. However, the positioning of the

insertion members

22 and 42 in the axial direction may be performed by the restriction pins 23 and the end portions 22 e of the

insertion members

22 and 42. In this case, for example, the ends 22 e of the

insertion members

22 and 42 abut on the restriction pins 23. Thus, the axial position of the

insertion members

22 and 42 is determined.

The present disclosure can be used for a bearing structure and a supercharger.

2: Bearing housing (housing) 2b: Bearing hole 2b ₁ : First bearing hole 2b ₂ : Second bearing hole 2c: Oil supply passage 2d: Large inner diameter hole 2e: Step surface 2g: Inner circumferential groove 7: Semi-floating bearing 7b: Radial bearing surface 7c: Radial bearing surface 7g: Thrust bearing surface 7h: Thrust bearing surface 7i: Projection 7k: Through hole 8: Shaft 22: Insertion member 22e: End 23: Regulator pin (Regulator) 30: Thrust bearing 31 : Thrust bearing 42: Penetration member C: Supercharger Ca: Supercharger S: Bearing structure

Claims

Semi-floating bearings housed in bearing holes,
A projecting portion that projects from the outer peripheral surface of the semi-floating bearing and extends in the circumferential direction;
An inner circumferential groove provided in the bearing hole, extending in the circumferential direction, and where the protrusion is located;
A restricting portion opposed to the projecting portion in the circumferential direction;
Bearing structure comprising:
The bearing structure according to claim 1, further comprising an oil supply passage opening to the inner peripheral groove.
Comprising two radial bearing surfaces formed on the inner peripheral surface of the semi-floating bearing,
3. The bearing structure according to claim 1, wherein a position of the protrusion in a central axis direction of the semi-floating bearing is between the two radial bearing surfaces. 4.
The bearing structure according to any one of claims 1 to 3, further comprising a thrust bearing surface formed on an end surface of the semi-floating bearing.
The bearing hole includes a first bearing hole and a second bearing hole,
An insertion member in which the first bearing hole is formed,
The second bearing hole, a large-diameter hole having an inner diameter larger than the second bearing hole and through which the insertion member is inserted, and extending from an inner peripheral surface of the second bearing hole to an inner peripheral surface of the large-diameter hole. A housing formed with a step surface which is separated from an end of the insertion member in a central axis direction of the semi-floating bearing,
With
The bearing structure according to claim 1, wherein the inner peripheral groove is formed between the insertion member and the step surface.
6. The bearing structure according to claim 1, wherein the protruding portion includes a through hole that penetrates in a central axis direction of the semi-floating bearing and through which the restricting portion is inserted.
A supercharger comprising the bearing structure according to any one of claims 1 to 6.