turbocharger

Abstract

This supercharger comprises: a housing that accommodates a turbine impeller; a nozzle ring accommodated in the housing; a plurality of nozzle vanes mounted to the nozzle ring; and a positioning unit for positioning the nozzle ring in the circumferential direction with respect to the housing. The positioning unit comprises: a positioning pin which is provided to one of the housing and the nozzle ring and which extends in the axial direction of the nozzle ring; a first engagement part which is provided to the other of the housing and the nozzle ring and which engages with the positioning pin; a second elastic member which biases the nozzle ring so as to be constrained in the circumferential direction with respect to the housing; and a second engagement part which engages with the second elastic member. The second elastic member and the second engagement part are provided to the housing and / or to the nozzle ring.

Description

Technical Field

[0001] The present disclosure relates to a supercharger. Background Art

[0002] For example, Patent Document 1 describes a supercharger. The supercharger described in Patent Document 1 comprises a turbine wheel fixed to a turbine shaft, a turbine housing accommodating the turbine wheel, a bearing housing pivotally supporting the turbine wheel, and a variable nozzle vane mechanism disposed in a link chamber between the turbine housing and the bearing housing. The variable nozzle vane mechanism includes a ring-shaped first nozzle plate disposed on the bearing housing side, a ring-shaped second nozzle plate disposed on the turbine housing side, and a plurality of nozzle vanes disposed between the first nozzle plate and the second nozzle plate and supported by the first nozzle plate and the second nozzle plate. An elastic body that urges the second nozzle plate toward the bearing housing side along the central axis of the second nozzle plate is disposed between the turbine housing and the second nozzle plate. Prior Art Literature Patent Literature

[0003] Patent Document 1 Japanese Unexamined Patent Application Publication No. 2021-76079 Summary of Invention Problem to be Solved by Invention

[0004] In the above-mentioned supercharger, the second nozzle plate is axially urged against the bearing housing by the elastic body, but no particular consideration is given to circumferential positioning of nozzle rings such as the first nozzle plate and the second nozzle plate relative to the bearing housing.

[0005] When positioning a nozzle ring circumferentially, a positioning pin extending axially from the nozzle ring is used, for example. In this case, to facilitate the assembly of the supercharger, the nozzle ring and the positioning pin need to be fitted in a clearance manner. However, when the nozzle ring and positioning pin are fitted in a clearance manner, the nozzle ring vibrates circumferentially due to engine vibrations, making wear on both the nozzle ring and the positioning pin more likely. Normally, the nozzle ring is pressed against the turbine housing or bearing housing and fixed by an elastic body that biases it axially, but this alone may not be sufficient to withstand engine vibrations.

[0006] The object of this disclosure is to provide a supercharger that can suppress wear of the nozzle ring and positioning pin. [Means for solving the problem]

[0007] A supercharger according to one aspect of the present disclosure comprises a turbine impeller fixed to a shaft, a housing that houses the turbine impeller and the shaft and rotatably supports the shaft, a nozzle ring housed in the housing and positioned radially outward from the turbine impeller, a plurality of nozzle vanes attached to the nozzle ring so as to be positioned along the circumferential direction of the nozzle ring, a first elastic member that biases the nozzle ring axially relative to the housing, and a positioning unit that positions the nozzle ring circumferentially relative to the housing. The positioning unit comprises a positioning pin provided on one of the housing and the nozzle ring and extending axially from the nozzle ring, a first engaging portion provided on the other of the housing and the nozzle ring and engaging with the positioning pin, a second elastic member that biases the nozzle ring to restrain it circumferentially relative to the housing, and a second engaging portion that engages with the second elastic member. The second elastic member and the second engaging portion are provided on at least one of the housing and the nozzle ring. That is, the second elastic member is provided on the housing or the nozzle ring, and the second engaging portion is provided on the housing or the nozzle ring. For example, both the second elastic member and the second engaging portion may be provided on the housing, or both may be provided on the nozzle ring. Alternatively, the second elastic member may be provided on the housing and the second engaging portion may be provided on the nozzle ring, or the second elastic member may be provided on the nozzle ring and the second engaging portion may be provided on the housing.

[0008] In such a supercharger, a positioning pin extending axially from the nozzle ring engages with a first engagement portion, thereby positioning the nozzle ring circumferentially relative to the housing. The second elastic member then engages with the second engagement portion of the nozzle ring, biasing it to restrain it circumferentially relative to the housing. Therefore, even if a circumferential gap exists between the positioning pin and the nozzle ring, the nozzle ring is restrained circumferentially relative to the housing by the second elastic member. As a result, circumferential play of the nozzle ring relative to the housing is suppressed, and even when external vibrations are applied to the nozzle ring, circumferential vibration of the nozzle ring relative to the housing is suppressed. This reduces wear on the nozzle ring and the positioning pin.

[0009] The positioning pin is provided in the housing, and the first engaging portion may be provided in the nozzle ring. In this configuration, the nozzle ring can be easily manufactured by performing the machining process to form the first and second engaging portions in the nozzle ring in the same process.

[0010] The housing has an inner circumferential surface facing the nozzle ring in the axial direction, and the second elastic member may be mounted on the housing so as to be positioned alongside the nozzle ring circumferentially with respect to the positioning pin, thereby biasing the nozzle ring in directions intersecting the axial and radial directions. In such a configuration, the nozzle ring is biased in directions intersecting the axial and radial directions by the second elastic member positioned alongside the nozzle ring circumferentially with respect to the positioning pin. Thus, the nozzle ring is reliably constrained circumferentially with respect to the housing.

[0011] The housing has an inner circumferential surface facing the nozzle ring in the axial direction, and a second elastic member may be attached to the inner circumferential surface of the housing and bias the nozzle ring in a direction intersecting the axial and radial directions. In such a configuration, the nozzle ring is biased in a direction intersecting the axial and radial directions by the second elastic member attached to the inner circumferential surface of the housing. Thus, the nozzle ring is reliably constrained circumferentially with respect to the housing.

[0012] The nozzle ring has an outer circumferential surface facing the housing in the radial direction of the nozzle ring, and the second engaging portion is a notch provided in the nozzle ring such that an opening is formed on the outer circumferential surface of the nozzle ring and has a tapered surface, and the second elastic member may bias the tapered surface radially inward of the nozzle ring. In such a configuration, when the second elastic member biases the tapered surface of the notch of the nozzle ring radially inward of the nozzle ring, the nozzle ring is biased in a direction intersecting the axial and radial directions by the combined component of the biasing force. Therefore, the nozzle ring is constrained circumferentially with respect to the housing by a simple structure.

[0013] The nozzle ring has an outer circumferential surface facing the housing in the radial direction of the nozzle ring, and the second engagement portion is provided on the nozzle ring such that an opening is formed on the outer circumferential surface of the nozzle ring, and is a notch having two inner surfaces facing the nozzle ring in the circumferential direction, and the second elastic member may bias one of the two inner surfaces. In this configuration, the nozzle ring is directly biased in a direction intersecting the axial and radial directions by the second elastic member biasing one of the inner surfaces of the notch of the nozzle ring. Therefore, the nozzle ring is constrained circumferentially to the housing with a simple structure.

[0014] The nozzle ring is provided with a common engagement portion that constitutes a first engagement portion and a second engagement portion. The second elastic member may be positioned adjacent to the positioning pin in the circumferential direction of the nozzle ring at the common engagement portion, thereby biasing the nozzle ring in directions that intersect the axial and radial directions. In this configuration, the nozzle ring is biased in directions that intersect the axial and radial directions by the second elastic member even without attaching the second elastic member to the housing. Therefore, the nozzle ring is constrained circumferentially to the housing while simplifying the housing structure.

[0015] Furthermore, a supercharger according to one aspect of the present disclosure includes a turbine impeller fixed to a shaft, a housing for housing the turbine impeller, a nozzle ring housed in the housing and positioned radially outward from the turbine impeller, a plurality of nozzle vanes attached to the nozzle ring, and a positioning unit for positioning the nozzle ring relative to the housing. The positioning unit is provided on at least one of the housing and the nozzle ring and includes a positioning pin extending in the axial direction of the nozzle ring, a pin engagement portion that engages with the positioning pin to position the nozzle ring circumferentially relative to the housing, and an elastic body that biases the nozzle ring to restrain it circumferentially relative to the housing.

[0016] Furthermore, at least one of the housing and the nozzle ring may be provided with an elastic engagement portion that engages with an elastic body. [Effects of the Invention]

[0017] According to this disclosure, wear of the nozzle ring and positioning pin can be suppressed. [Brief explanation of the drawing]

[0018] [Figure 1] This is a cross-sectional view showing a turbocharger according to the first embodiment of this disclosure. [Figure 2] This is an exploded perspective view of a variable capacitance mechanism. [Figure 3] This is a plan view of the variable capacitance mechanism. [Figure 4] This is a plan view (including a partial cross-section) showing the positioning unit together with the nozzle ring. [Figure 5] This is a perspective view of the positioning pin and spring member. [Figure 6] Figure 4 is a cross-sectional view of the positioning unit. [Figure 7] This is a plan view (including a partial cross-section) showing a positioning unit as a comparative example, along with a nozzle ring. [Figure 8] Figure 7 is a cross-sectional view of the positioning unit. [Figure 9] It is a plan view (including a partial cross-section) showing a modification of a positioning unit together with a nozzle ring as a supercharger according to a second embodiment of the present disclosure. [Figure 10] It is a plan view (including a partial cross-section) showing another modification of a positioning unit together with a nozzle ring as a supercharger according to a third embodiment of the present disclosure. [Figure 11] It is a plan view (including a partial cross-section) showing still another modification of a positioning unit together with a nozzle ring as a supercharger according to a fourth embodiment of the present disclosure. [Figure 12] It is a cross-sectional view showing a positioning unit as a supercharger according to a fifth embodiment of the present disclosure. MODE FOR CARRYING OUT THE INVENTION

[0019] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. In the description of the drawings, the same or equivalent elements are denoted by the same reference numerals, and redundant description will be omitted.

[0020] Figure 1 is a cross-sectional view showing a supercharger according to a first embodiment of the present disclosure. In Figure 1, the supercharger 1 of the present embodiment is a variable capacity supercharger. The supercharger 1 is applied to, for example, an engine of a vehicle or a ship.

[0021] The supercharger 1 includes a turbine, a compressor, and a shaft connecting the turbine and the compressor. The turbine includes a turbine impeller and a turbine housing. The compressor includes a compressor impeller and a compressor housing.

[0022] The turbine impeller 5 is fixed to one end of the shaft 4. The compressor impeller 7 is fixed to the other end of the shaft 4. A bearing housing 10 is positioned between the turbine housing 6 and the compressor housing 8. The bearing housing 10 is fixed to the turbine housing 6 and the compressor housing 8. The bearing housing 10 houses the shaft 4 and rotatably supports the shaft 4 via bearings 9.

[0023] The turbine housing 6 houses the turbine impeller 5. The turbine housing 6 has a scroll passage 11 and an outlet 12 that communicates with the scroll passage 11. The scroll passage 11 is provided around the turbine impeller 5. Exhaust gas discharged from the engine flows into the turbine housing 6 from an inlet (not shown), then flows through the scroll passage 11 and is guided to the turbine impeller 5, causing the turbine impeller 5 to rotate. The exhaust gas then flows out of the turbine housing 6 through the outlet 12.

[0024] The compressor housing 8 houses the compressor impeller 7. The compressor housing 8 has an intake port 13 and a scroll passage 14 that communicates with the intake port 13. The scroll passage 14 is provided around the compressor impeller 7. When the turbine impeller 5 rotates, the compressor impeller 7 rotates via the shaft 4. As a result, outside air is drawn into the compressor housing 8 from the intake port 13. The drawn-in air is compressed as it passes through the compressor impeller 7 and the scroll passage 14. The compressed air is discharged from a discharge port (not shown) and supplied to the engine.

[0025] Furthermore, as shown in Figure 2, the turbine 2 is equipped with a variable capacitance mechanism 20 for adjusting the nozzle opening (capacity). The variable capacitance mechanism 20 includes a CC plate (clearance control plate) 21, a nozzle ring 22, a CC pin (clearance control pin) 23, a plurality of nozzle vanes 24, a drive ring 25, a plurality of nozzle link plates 26, and a drive link plate 27.

[0026] The CC plate 21 has a disc shape. The central axis of the CC plate 21 coincides with the rotation axis X of the shaft 4. The CC plate 21 is arranged to surround the turbine impeller 5 around the rotation axis X. The CC plate 21 is positioned radially outward of the turbine impeller 5. Radially outward means a position that is radially farther from the rotation axis X than a certain reference (for example, the turbine impeller 5). Radially inward means a position that is radially closer to the rotation axis X than a certain reference.

[0027] The CC plate 21 has a main plate surface 21a facing the inner wall surface 6a of the turbine housing 6 and a back plate surface 21b facing the nozzle ring 22. The back plate surface 21b is the surface of the CC plate 21 opposite to the main plate surface 21a. The CC plate 21 is provided with a plate hole 21h that penetrates from the main plate surface 21a to the back plate surface 21b. The CC plate 21 is also provided with a plurality (for example, three) of pin holes 29. The pin holes 29 are arranged, for example, at equal intervals along the circumferential direction of the CC plate 21.

[0028] The nozzle ring 22 has a disc shape. The central axis of the nozzle ring 22 coincides with the rotation axis X of the shaft 4. The nozzle ring 22 is located on the bearing housing 10 side of the CC plate 21 in the direction of the rotation axis X (axial direction). The nozzle ring 22 is positioned between the CC plate 21 and the bearing housing 10. The nozzle ring 22 is positioned radially outward of the turbine impeller 5. The nozzle ring 22 is positioned to surround the turbine impeller 5 or the shaft 4 around the rotation axis X.

[0029] The nozzle ring 22 has a cylindrical ring body portion 30, an outer flange portion 31 that protrudes radially outward from the ring body portion 30, and an inner flange portion 32 that protrudes radially inward from the ring body portion 30.

[0030] The ring body portion 30 has an outer circumferential surface 30c. The ring body portion 30 is provided with a plurality of nozzle shaft holes 33 and notches 34 and 35. The nozzle shaft holes 33 are arranged, for example, at equal intervals along the circumferential direction of the ring body portion 30. The notches 34 and 35 will be described in detail later.

[0031] The outer flange portion 31 has an outer circumferential surface 31c. The outer flange portion 31 is provided with a plurality (three in this case) of pin holes 36. The central axis of the pin holes 36 coincides with the central axis of the pin holes 29 of the CC plate 21.

[0032] The nozzle ring 22 has a main ring surface 22a facing the back surface 21b of the CC plate 21, and a back surface 22b facing the bearing housing 10. The back surface 22b is the surface of the nozzle ring 22 opposite to the main ring surface 22a. The nozzle ring 22 is provided with a ring hole 22h that penetrates from the main ring surface 22a to the back surface 22b. The back surface 22b includes a main body back surface 30b, an outer flange back surface 31b, and an inner flange back surface 32b. A portion of the main body back surface 30b faces the nozzle link plate 26. The outer flange back surface 31b faces the drive ring 25.

[0033] The CC pin 23 connects the CC plate 21 and the nozzle ring 22. One end of the CC pin 23 is inserted into the pin hole 29 of the CC plate 21. The other end of the CC pin 23 is inserted into the pin hole 36 of the nozzle ring 22. The CC pin 23 defines the gap between the CC plate 21 and the nozzle ring 22. The CC pin 23 functions as a spacer, forming a gap between the CC plate 21 and the nozzle ring 22 in which the nozzle vane 24 is positioned.

[0034] Multiple nozzle vanes 24 are arranged between the CC plate 21 and the nozzle ring 22. The nozzle vanes 24 are arranged, for example, at equal intervals along the circumferential direction of the nozzle ring 22. A nozzle shaft 37 extending toward the nozzle ring 22 is fixed to the nozzle vanes 24. The nozzle shaft 37 is inserted through the nozzle shaft hole 33 of the nozzle ring 22. The tip of the nozzle shaft 37 protrudes from the back surface 30b of the main body of the nozzle ring 22. The diameter of the nozzle shaft 37 is slightly smaller than the diameter of the nozzle shaft hole 33. Therefore, the nozzle shaft 37 is rotatable relative to the nozzle ring 22. A nozzle link plate 26 is fixed to the tip of the nozzle shaft 37.

[0035] The drive ring 25 is positioned on the back surface 31b of the outer flange of the nozzle ring 22. The drive ring 25 surrounds the ring body 30 of the nozzle ring 22 along its circumference. The drive ring 25 is coaxial with respect to the nozzle ring 22. The drive ring 25 is rotatable relative to the nozzle ring 22 about the rotation axis X.

[0036] The drive ring 25 has a main ring surface 25a facing the outer flange back surface 31b of the nozzle ring 22, and a back ring surface 25b facing the bearing housing 10. The back ring surface 25b is the surface of the drive ring 25 opposite to the main ring surface 25a. Multiple nozzle link plates 26 are arranged on the back ring surface 25b. One drive link plate 27 is also arranged on the back ring surface 25b.

[0037] As shown in Figure 3, the drive ring 25 has a plurality of joints 38 arranged along the circumferential direction. Each joint 38 consists of a pair of upright portions 38a that sandwich the tip portions of the nozzle link plate 26 and the drive link plate 27. The upright portions 38a protrude from the back surface 25b of the ring. Figure 3 is a plan view of the variable displacement mechanism 20 as seen from the intake port 13 side of the compressor 3.

[0038] The nozzle link plates 26 are arranged, for example, at equal intervals along the circumferential direction of the drive ring 25. The number of nozzle link plates 26 is equal to the number of nozzle vanes 24. The nozzle link plates 26 are bar-shaped.

[0039] The base end of the nozzle link plate 26 is positioned on the back surface 30b of the nozzle ring 22. A nozzle shaft hole 39 is provided at the base end of the nozzle link plate 26. The tip of the nozzle shaft 37 is inserted into the nozzle shaft hole 39. In this state, the tip of the nozzle shaft 37 is fixed to the nozzle link plate 26, for example, by crimping.

[0040] The tip of the nozzle link plate 26 is fitted into a pair of upright portions 38a of the joint 38. Specifically, the tip of the nozzle link plate 26 is positioned between the pair of upright portions 38a and is not fixed to the upright portions 38a. Therefore, the nozzle link plate 26 is not fixed to the drive ring 25.

[0041] The drive link plate 27 is positioned between two nozzle link plates 26 that are aligned in the circumferential direction. The drive link plate 27 has the same structure as the nozzle link plates 26. The drive link plate 27 is connected to a drive mechanism (not shown).

[0042] In such a variable displacement mechanism 20, when the drive ring 25 receives a driving force from the drive link plate 27, the drive ring 25 rotates about the rotation axis X. As a result, the tip of the nozzle link plate 26 moves along the circumferential direction in conjunction with the rotation of the drive ring 25. Therefore, the nozzle link plate 26 rotates about the nozzle axis 37. When the nozzle link plate 26 rotates, the nozzle axis 37 rotates, causing the nozzle vanes 24 to rotate. This changes the spacing between adjacent nozzle vanes 24. In other words, the cross-sectional area between adjacent nozzle vanes 24 changes.

[0043] Furthermore, the turbine 2 is equipped with a spring member 40 (see Figure 1) that biases the variable displacement mechanism 20 axially relative to the turbine housing 6. For example, a disc spring, coil spring, or ring spring can be used as the spring member 40. The spring member 40 constitutes a first elastic member that biases the nozzle ring 22 axially relative to the turbine housing 6.

[0044] The spring member 40 is positioned in the space between the ring-shaped heat shield 41 and the bearing housing 10. The heat shield 41 is positioned radially inward of the nozzle ring 22. The heat shield 41 is held in place by the spring member 40 by being pressed against the inner flange portion 32 of the nozzle ring 22. The spring member 40 is positioned between the back surface 41b of the heat shield 41 and the inner wall surface 10a of the bearing housing 10.

[0045] The variable displacement mechanism 20 is positioned and held in a holding portion 50 of the bearing housing 10. The holding portion 50 has a holding surface 50a that faces the ring back surface 22b of the nozzle ring 22 and the ring back surface 25b of the drive ring 25. The holding surface 50a is part of the inner wall surface 10a of the bearing housing 10. The holding surface 50a is an example of the inner circumferential surface of the bearing housing 10 and includes a portion that faces the nozzle ring 22 in the axial direction and a portion that faces the nozzle ring 22 in the radial direction.

[0046] As shown in Figure 4, the holding portion 50 is provided with a positioning pin 51 and a spring member 52. The positioning pin 51 and the spring member 52 cooperate with the notches 34 and 35 provided in the nozzle ring 22 to form a positioning unit 53 (for example, a positioning assembly) that positions the nozzle ring 22 circumferentially relative to the bearing housing 10. The positioning unit 53 has, for example, the positioning pin 51, the spring member 52, and the notches 34 and 35. Figure 4 is a plan view of the nozzle ring 22 and the positioning unit 53 as seen from the intake port 13 side of the compressor 3.

[0047] The positioning pin 51 is positioned in a location that overlaps with the notch 34 in the holding portion 50. The spring member 52 is positioned in a location that overlaps with the notch 35 in the holding portion 50. In other words, the spring member 52 is attached to the holding portion 50 so as to be positioned in line with the positioning pin 51 in the circumferential direction of the nozzle ring 22. The positioning pin 51 extends axially toward the nozzle ring 22. The positioning pin 51 has a cylindrical shape, as shown in Figure 5(a). However, the shape of the positioning pin 51 is not limited to a cylindrical shape and may be a prismatic shape or the like.

[0048] The spring member 52 constitutes a second elastic member that biases the nozzle ring 22 to restrain it circumferentially relative to the bearing housing 10. The spring member 52 is an example of an elastic body. The spring member 52 biases the nozzle ring 22 in directions that intersect the axial and radial directions. The directions that intersect the axial and radial directions of the nozzle ring 22 are the circumferential or tangential directions of the nozzle ring 22. The tangential direction of the nozzle ring 22 is the direction perpendicular to the axial and radial directions of the nozzle ring 22, and is substantially the circumferential direction of the nozzle ring 22.

[0049] As shown in Figure 5(b), the spring member 52 has a substantially cylindrical base 54 and a biasing portion 55 integrated with the base 54. The base 54 is provided with a slit 56 extending in the axial direction. The biasing portion 55 extends in a J-shape from the portion of the base 54 opposite to the slit 56 at one end in the axial direction toward the slit 56. Both the base 54 and the biasing portion 55 are elastically deformable. The spring member 52 is formed, for example, by pressing a thin metal sheet into an inverted T-shape and then bending it.

[0050] As shown in Figure 6, the retaining portion 50 of the bearing housing 10 is provided with mounting holes 57 and 58, which have a circular cross-section. The mounting holes 57 and 58 are provided so that openings are formed in the portion of the retaining surface 50a facing the nozzle ring 22. The mounting hole 57 has a circular bottom surface 57a and a circumferential surface 57b. The mounting hole 58 has a circular bottom surface 58a and a circumferential surface 58b. Note that Figure 6 shows a cross-section along the circumferential direction of the nozzle ring 22.

[0051] A portion of the positioning pin 51 is inserted into the mounting hole 57. A portion of the base 54 of the spring member 52 is inserted into the mounting hole 58. At this time, since the base 54 is provided with a slit 56, the base 54 can be inserted into the mounting hole 58 while its shape or diameter is matched to the diameter of the mounting hole 58. The positioning pin 51 is fixed to the holding part 50 while inserted into the mounting hole 57. The spring member 52 is fixed to the holding part 50 while inserted into the mounting hole 58.

[0052] The notches 34 and 35 are provided in the ring body portion 30 of the nozzle ring 22. The notches 34 and 35 are provided so as to form an opening in the outer peripheral surface 30c of the ring body portion 30. The notches 34 and 35 have a U-shape in plan view. The notch 34 has two inner surfaces 34a facing each other in the circumferential direction of the nozzle ring 22 and a curved inner back surface 34b connecting these inner surfaces 34a. The notch 35 has two inner surfaces 35a facing each other in the circumferential direction of the nozzle ring 22 and a curved inner back surface 35b connecting these inner surfaces 35a. The notch 34 constitutes a first engagement portion that engages with the positioning pin 51. Engagement between the positioning pin 51 and the notch 34 means that their relative movement is restricted by contact with each other. The notch 34 is an example of a pin engagement portion. The notch 35 constitutes a second engagement portion that engages with the spring member 52. The notch 35 is an example of an elastic engagement portion that engages with the spring member 52.

[0053] Once the variable displacement mechanism 20 is assembled to the holding portion 50 of the bearing housing 10, the nozzle ring 22 is positioned circumferentially relative to the bearing housing 10 by the positioning unit 53.

[0054] Specifically, as shown in Figures 4 and 6, the tip of the biasing portion 55 of the spring member 52 abuts against one inner surface 35a of the notch 35. The biasing force of the biasing portion 55 causes the tip of the biasing portion 55 to press against one inner surface 35a (see arrow P in the figures). As a result, the nozzle ring 22 moves slightly in the circumferential direction, and the positioning pin 51 abuts against one inner surface 34a of the notch 34. This restricts the circumferential movement of the nozzle ring 22 relative to the bearing housing 10.

[0055] The embodiment shown in Figure 6 shows an example in which the positioning pin 51 and the spring member 52 are provided in the bearing housing 10, and the notches 34 and 35 are provided in the nozzle ring 22. However, in the embodiment shown in Figure 6, it is also possible that the positioning pin 51 and the notch 35 are provided in the bearing housing 10, and the notch 34 and the spring member 52 are provided in the nozzle ring 22.

[0056] Figure 7 is a plan view showing a positioning unit 100 as a comparative example, together with a nozzle ring 22. In Figure 7, in the positioning unit 100 of this comparative example, two positioning pins 51 are attached to the holding portion 50 of the bearing housing 10, and two notches 34 are provided in the nozzle ring 22.

[0057] However, in such a positioning unit 100, if external vibrations exceeding the frictional holding force of the spring member 40 are applied to the variable displacement mechanism 20 from the engine, the nozzle ring 22 will have difficulty withstanding the external vibrations. That is, as shown in Figure 8, considering the ease of assembly of the supercharger 1, a gap S along the circumferential direction exists between the positioning pin 51 and the nozzle ring 22. Therefore, when external vibrations are applied to the variable displacement mechanism 20, the nozzle ring 22 vibrates in the circumferential direction, causing looseness of the nozzle ring 22 relative to the bearing housing 10, and resulting in wear of the nozzle ring 22 and the positioning pin 51. Figure 8 shows a cross-section of the nozzle ring 22 along the circumferential direction.

[0058] If the nozzle ring 22 and the positioning pin 51 wear down due to circumferential vibration of the nozzle ring 22, the positional relationship of the link system that controls the opening degree of the nozzle vane 24 will shift. As a result, the nozzle vane 24 may open excessively, causing it to come into contact with the turbine impeller 5 and resulting in damage to the nozzle vane 24, or the nozzle vane 24 may not be maintained at the appropriate opening degree. This can lead to a decrease in the durability of the variable displacement mechanism 20 and a decrease in engine output.

[0059] In this embodiment, the nozzle ring 22 is positioned circumferentially relative to the bearing housing 10 by the engagement of a positioning pin 51 extending axially from the nozzle ring 22 with a notch 34 of the nozzle ring 22. Then, the spring member 52 engages with the notch 35 of the nozzle ring 22, biasing the nozzle ring 22 to restrain it circumferentially relative to the bearing housing 10. The engagement between the spring member 52 and the notch 35 means that they abut each other, thereby restricting their relative movement. Therefore, even if there is a gap S along the circumferential direction between the positioning pin 51 and the nozzle ring 22, the nozzle ring 22 is restrained circumferentially relative to the bearing housing 10 by the spring member 52. As a result, circumferential rattle of the nozzle ring 22 relative to the bearing housing 10 is suppressed, and even if external vibrations are applied to the nozzle ring 22, circumferential vibration of the nozzle ring 22 relative to the bearing housing 10 is suppressed. This suppresses wear of the nozzle ring 22 and the positioning pin 51. As a result, the durability of the variable capacity mechanism 20 is increased, and the marketability of the supercharger 1 is improved.

[0060] Furthermore, in this embodiment, the positioning pin 51 is provided in the bearing housing 10, and the notch 34 is provided in the nozzle ring 22. Therefore, the nozzle ring 22 can be easily manufactured by performing the machining process to form the notches 34 and 35 in the nozzle ring 22 in the same process.

[0061] Furthermore, in this embodiment, the nozzle ring 22 is biased in directions intersecting the axial and radial directions by spring members 52 arranged circumferentially with respect to the positioning pin 51. Therefore, the nozzle ring 22 is reliably constrained circumferentially with respect to the bearing housing 10.

[0062] In this embodiment, a spring member 52 having a base portion 54 and a biasing portion 55 is used, but the second elastic member that biases the nozzle ring 22 to restrain the bearing housing 10 in the circumferential direction is not limited to this and can be deformed in various ways. For example, the second elastic member may be a spring member made by simply winding a thin metal sheet.

[0063] Furthermore, in this embodiment, the positioning pin 51 provided in the bearing housing 10 engages with the notch 34 of the nozzle ring 22, but the first engaging portion that engages with the positioning pin 51 is not limited to the notch 34. The first engaging portion may be, for example, an opening (hole) that penetrates from the main ring surface 22a to the back surface 22b of the nozzle ring 22, or a recess (recess) provided on the back surface 22b of the nozzle ring 22. The second engaging portion that engages with the spring member 52 attached to the bearing housing 10 is also not limited to the notch 35, but may be a hole or a recess.

[0064] Figure 9 is a plan view (including a partial cross-section) showing a modified example of the positioning unit together with a nozzle ring as a supercharger according to the second embodiment of this disclosure, and corresponds to Figure 4.

[0065] In Figure 9, the supercharger 1A of this embodiment is equipped with a positioning unit 53A instead of the positioning unit 53 in the first embodiment described above. The positioning unit 53A has the positioning pin 51 attached to the bearing housing 10 and a V-shaped spring member 61 attached to the turbine housing 6.

[0066] The spring member 61 is attached to the inner wall portion 60 of the turbine housing 6. The inner wall portion 60 has an inner circumferential surface 60a that faces the nozzle ring 22 in the radial direction. Specifically, the inner circumferential surface 60a faces the outer circumferential surface 31c of the outer flange portion 31 of the nozzle ring 22. The inner wall portion 60 is provided with a fixing recess 62. The fixing recess 62 is provided such that an opening is formed in the inner circumferential surface 60a. Both ends of the spring member 61 are fixed to the corners of the fixing recess 62. The spring member 61 is attached to the inner circumferential surface 60a of the turbine housing 6 and constitutes a second elastic member that biases the nozzle ring 22 in directions intersecting the axial and radial directions. The spring member 61 is an example of an elastic body.

[0067] Furthermore, the positioning unit 53A has the above-mentioned notch 34 and a V-shaped notch 63 in plan view, provided in the nozzle ring 22. The notch 63 is provided in the outer flange portion 31 of the nozzle ring 22. The notch 63 is provided such that an opening is formed in the outer peripheral surface 31c of the outer flange portion 31. The notch 63 is provided at a position circumferentially spaced apart from the notch 34 in the nozzle ring 22. The notch 63 has two tapered surfaces 63a. The tapered surfaces 63a are surfaces that intersect the radial direction of the nozzle ring 22 at an oblique angle. The notch 63 constitutes a second engaging portion that engages with the spring member 61. The notch 63 is an example of an elastic engaging portion that engages with the spring member 61.

[0068] The tip (center) of the spring member 61 abuts against one of the tapered surfaces 63a of the notch 63. The spring member 61 biases one of the tapered surfaces 63a of the notch 63 radially inward of the nozzle ring 22 (see arrow A in the figure). At this time, the nozzle ring 22 is also biased tangentially by the combined component of the biasing force of the spring member 61 (see arrow B in the figure).

[0069] In this embodiment, the nozzle ring 22 is biased in directions intersecting the axial and radial directions by a spring member 61 attached to the inner circumferential surface 60a of the turbine housing 6. Therefore, the nozzle ring 22 is reliably restrained circumferentially with respect to the bearing housing 10.

[0070] Furthermore, in this embodiment, when the spring member 61 biases the tapered surface 63a of the notch 63 of the nozzle ring 22 radially inward, the nozzle ring 22 is biased in a direction intersecting the axial and radial directions by the combined component of the biasing force. Therefore, the nozzle ring 22 is constrained circumferentially with respect to the bearing housing 10 by a simple structure.

[0071] In this embodiment, a V-shaped spring member 61 is used, but the second elastic member that biases the tapered surface 63a of the notch 63 of the nozzle ring 22 radially inward is not limited to this and can be deformed in various ways. For example, the second elastic member may be a normal coil spring or the like.

[0072] Furthermore, in this embodiment, a V-shaped notch 63 having two tapered surfaces 63a is provided in the nozzle ring 22, but the form is not particularly limited, and a notch having one tapered surface may also be provided in the nozzle ring 22.

[0073] Furthermore, in this embodiment, the spring member 61 biases the tapered surface 63a of the notch 63 radially inward of the nozzle ring 22, thereby biasing the nozzle ring 22 in a direction intersecting the axial and radial directions. However, the embodiment is not limited to this configuration, and a structure in which the tapered surface 63a of the notch 63 is directly biased by a second elastic member in a direction intersecting the axial and radial directions of the nozzle ring 22 may also be used.

[0074] Furthermore, in this embodiment, the spring member 61 is attached to the inner circumferential surface 60a of the turbine housing 6, but the configuration is not particularly limited, and depending on the structure of the supercharger 1A, a second elastic member such as the spring member 61 may be attached to the inner circumferential surface of the bearing housing 10.

[0075] Figure 10 is a plan view (including a partial cross-section) showing another modified example of the positioning unit as a supercharger according to the third embodiment of the present disclosure, and corresponds to Figure 4.

[0076] In Figure 10, the supercharger 1B of this embodiment is equipped with a positioning unit 53B instead of the positioning unit 53 in the first embodiment described above. The positioning unit 53B has the positioning pin 51 attached to the bearing housing 10 and the spring member 52 attached to the turbine housing 6.

[0077] The spring member 52 is attached to the inner wall portion 60 of the turbine housing 6. The inner wall portion 60 has an inner circumferential surface 60a that faces the nozzle ring 22 in the radial direction. The inner wall portion 60 is provided with a mounting hole portion 65 with a circular cross-section. The mounting hole portion 65 is provided so as to form an opening in the inner circumferential surface 60a. The mounting hole portion 65 has a circular bottom surface 65a and a circumferential surface 65b. The base portion 54 of the spring member 52 is fixed to the inner wall portion 60 in a state where it is inserted into the mounting hole portion 65. The spring member 52 is attached to the inner circumferential surface 60a of the turbine housing 6 and constitutes a second elastic member that biases the nozzle ring 22 in directions intersecting the axial and radial directions. The spring member 52 is an example of an elastic body.

[0078] Furthermore, the positioning unit 53B has the above-mentioned notch 34 and a rectangular notch 66 in plan view provided in the nozzle ring 22. The notch 66 is provided in the outer flange portion 31 of the nozzle ring 22. The notch 66 is provided so as to form an opening in the outer peripheral surface 31c of the outer flange portion 31. The outer peripheral surface 31c of the outer flange portion 31 faces the inner peripheral surface 60a of the inner wall portion 60. The notch 66 is provided at a position circumferentially spaced apart from the notch 34 in the nozzle ring 22.

[0079] The notch 66 has two inner surfaces 66a facing each other in the circumferential direction of the nozzle ring 22, and a planar inner back surface 66b connecting these inner surfaces 66a. The two inner surfaces 66a are formed to be parallel, for example. The notch 66 constitutes a second engaging portion that engages with the spring member 52. The notch 66 is an example of an elastic engaging portion that engages with the spring member 52.

[0080] The tip of the biasing portion 55 of the spring member 52 abuts against one inner surface 66a of the notch 66. The spring member 52 biases one inner surface 66a of the notch 66 in a direction intersecting the axial and radial directions of the nozzle ring 22 (see arrow Q in the figure). The spring member 52 does not bias the other inner surface 66a of the notch 66 in a direction intersecting the axial and radial directions of the nozzle ring 22.

[0081] In this embodiment, the spring member 52 biases one inner surface 66a of the notch 66 of the nozzle ring 22, thereby directly biasing the nozzle ring 22 in directions intersecting the axial and radial directions. Consequently, the nozzle ring 22 is constrained circumferentially with respect to the bearing housing 10 by a simple structure.

[0082] In this embodiment, a J-shaped spring member 52 is used, but the second elastic member that biases only one inner surface 66a of the notch 66 of the nozzle ring 22 is not limited to this and can be deformed in various ways.

[0083] Furthermore, in this embodiment, a rectangular notch 66 is provided in the nozzle ring 22 in a plan view. However, the shape of the notch is not particularly limited as long as it has two inner surfaces facing each other in the circumferential direction of the nozzle ring 22. It may be U-shaped in a plan view, similar to the notch 34, or it may be trapezoidal in a plan view, etc.

[0084] Furthermore, in this embodiment as well, depending on the structure of the supercharger 1B, the second elastic member, such as the spring member 52, may be attached to the inner circumferential surface of the bearing housing 10 instead of the turbine housing 6.

[0085] Figure 11 is a plan view showing yet another modification of the positioning unit as a supercharger according to the fourth embodiment of the present disclosure, and corresponds to Figure 4.

[0086] In Figure 11, the supercharger 1C of this embodiment is equipped with a positioning unit 53C instead of the positioning unit 53 in the first embodiment described above. The positioning unit 53C has the positioning pin 51 attached to the bearing housing 10 and a V-shaped spring member 71 provided on the nozzle ring 22. The spring member 71 constitutes a second elastic member that biases the nozzle ring 22 in directions intersecting the axial and radial directions. The spring member 71 is an example of an elastic body.

[0087] Furthermore, the positioning unit 53C has a notch 72 in the nozzle ring 22 that is substantially rectangular in plan view. The notch 72 is provided in the ring body 30 of the nozzle ring 22 so as to open into the outer circumferential surface 30c of the ring body 30. The notch 72 has two inner surfaces 72a facing each other in the circumferential direction of the nozzle ring 22, and a substantially planar inner back surface 72b connecting these inner surfaces 72a. The notch 72 constitutes a first engagement portion that engages with the positioning pin 51, and also constitutes a second engagement portion that engages with the spring member 71. In other words, the notch 72 is a single common engagement portion that constitutes the first engagement portion and the second engagement portion. The notch 72 is an example of an elastic engagement portion that engages with the spring member 71.

[0088] The spring member 71 is positioned in the notch 72 together with the positioning pin 51. The spring member 71 is positioned in the notch 72 adjacent to the positioning pin 51 in the circumferential direction. One end of the spring member 71 is in contact with the positioning pin 51. The other end of the spring member 71 is in contact with one inner surface 72a of the notch 72. The spring member 71 biases the nozzle ring 22 in directions intersecting the axial and radial directions by biasing one inner surface 72a of the notch 72 (see arrow R in the figure).

[0089] In this embodiment, by arranging the spring member 71 in the notch 72 so as to be adjacent to the positioning pin 51 and the nozzle ring 22 in the circumferential direction, the nozzle ring 22 is biased by the spring member 71 in directions that intersect the axial and radial directions, even without attaching the spring member 71 to the bearing housing 10 and the turbine housing 6. Therefore, the nozzle ring 22 is constrained circumferentially with respect to the bearing housing 10 while simplifying the structure of the bearing housing 10 or the turbine housing 6.

[0090] In this embodiment, a V-shaped spring member 71 is used, but the second elastic member that biases one of the inner surfaces 72a of the notch 72 of the nozzle ring 22 is not limited to this and can be deformed in various ways.

[0091] Furthermore, although the nozzle ring 22 is provided with a notch 72, the common engagement portion that engages with the positioning pin 51 and the spring member 71 is not limited to the notch 72, and may be a hole that penetrates from the main ring surface 22a to the back surface 22b of the nozzle ring 22, or a hole (recess) that opens into the back surface 22b of the nozzle ring 22.

[0092] Although several embodiments of the present disclosure have been described above, the present disclosure is not limited to the above embodiments. For example, in the above embodiments, a notch that engages with the second elastic member is provided on the nozzle ring 22 as the second engaging portion, but the present disclosure is not limited to such a form. For example, a projection that engages with the second elastic member may be provided on the nozzle ring 22 as the second engaging portion, or the outer peripheral surface 30c or outer peripheral surface 31c of the nozzle ring 22 may be used as the second engaging portion that engages with the second elastic member.

[0093] Furthermore, in the above embodiment, the nozzle ring 22 is biased axially relative to the turbine housing 6 by the spring member 40, but the configuration is not particularly limited, and depending on the structure of the supercharger, the nozzle ring 22 may be biased axially relative to the bearing housing 10 by some kind of elastic body.

[0094] Furthermore, although the bearing housing 10 is provided with only one positioning pin 51 in the above embodiment, the number of positioning pins 51 may be multiple. Similarly, the number of second elastic members may also be multiple.

[0095] Furthermore, in the above embodiment, the positioning pin 51 is provided in the bearing housing 10 and the first engaging portion that engages with the positioning pin 51 is provided in the nozzle ring 22, but the embodiment is not limited to this configuration. The positioning pin 51 may be provided in the nozzle ring 22 and the first engaging portion may be provided in the bearing housing 10. In this case, the first engaging portion is, for example, a hole provided in the holding portion 50 of the bearing housing 10. It is permissible to install it.

[0096] Figure 12 is a cross-sectional view showing a positioning unit as a supercharger according to the fifth embodiment of this disclosure, and corresponds to Figure 6.

[0097] In Figure 12, the supercharger of this embodiment includes a positioning unit 53D in place of the positioning unit 53 in the first embodiment described above. The positioning unit 53D includes a positioning pin 51D and a spring member 52D. The positioning pin 51D has substantially the same structure as the positioning pin 51, and the spring member 52D has substantially the same structure as the spring member 52. These identical structures are denoted by the same reference numerals as the positioning pin 51 or the spring member 52.

[0098] The nozzle ring 22 is provided with mounting holes 57D and 58D. Part of the positioning pin 51D is inserted into the mounting hole 57D. Part of the base 54 of the spring member 52D is inserted into the mounting hole 58D. The positioning pin 51D is fixed to the nozzle ring 22 while inserted into the mounting hole 57D. The spring member 52D is fixed to the nozzle ring 22 while inserted into the mounting hole 58D.

[0099] The notches 34D and 35D are provided in the bearing housing 10. Notch 34D constitutes a first engaging portion that engages with the positioning pin 51D. Notch 34D is an example of a pin engaging portion. Notch 35D constitutes a second engaging portion that engages with the spring member 52. The spring member 52 is an example of an elastic body, and notch 35D is an example of an elastic body engaging portion that engages with the spring member 52. Notches 34D and 35D have substantially the same structure as notches 34 and 35, and these same structures are denoted by the same reference numerals as notches 34 and 35.

[0100] The positioning pin 51D and the spring member 52D cooperate with the notches 34D and 35D provided in the bearing housing 10 to form a positioning unit 53D (for example, a positioning assembly) that positions the nozzle ring 22 circumferentially relative to the bearing housing 10.

[0101] The spring member 52D is attached to the nozzle ring 22 so as to be positioned in the circumferential direction of the nozzle ring 22 with respect to the positioning pin 51D. The positioning pin 51D extends axially toward the nozzle ring 22.

[0102] The spring member 52D constitutes a second elastic member that biases the nozzle ring 22 so as to restrain it circumferentially relative to the bearing housing 10. The spring member 52D biases the nozzle ring 22 in a direction intersecting the axial and radial directions by the biasing portion 55 interfering with the bearing housing 10. The direction intersecting the axial and radial directions of the nozzle ring 22 is the circumferential or tangential direction of the nozzle ring 22. The tangential direction of the nozzle ring 22 is the direction perpendicular to the axial and radial directions of the nozzle ring 22 and is substantially the circumferential direction of the nozzle ring 22.

[0103] The embodiment shown in Figure 12 shows an example in which the positioning pin 51D and the spring member 52D are provided on the nozzle ring 22, and the notches 34D and 35D are provided on the bearing housing 10. However, in the embodiment shown in Figure 12, it is also possible that the positioning pin 51D and the notch 35D are provided on the nozzle ring 22, and the notch 34D and the spring member 52D are provided on the bearing housing 10. [Explanation of Symbols]

[0104] 1,1A,1B,1C Supercharger 4 shafts 5 Turbine blade vehicle 6. Turbine Housing (Housing) 10 Bearing housing (housing) 22 Nozzle Rings 24 Nozzle vanes 30c outer circumferential surface 31c Outer surface 34,34D Notch (First engagement part, pin engagement part) 35,35D Notch (Second engagement part, Elastic engagement part) 40 Spring member (first elastic member) 51, 51D Positioning pins 52, 52D Spring member (second elastic member, elastic body) 53, 53A, 53B, 53C, 53D Positioning Unit 60a Inner surface 61. Spring member (second elastic member, elastic body) 63 Notch (second engagement portion, elastic engagement portion) 63a Tapered surface 66 Notch (second engagement portion, elastic engagement portion) 66a Inside surface 71. Spring member (second elastic member, elastic body) 72 Notches (first engagement part, second engagement part, common engagement part, pin engagement part, elastic engagement part)

Claims

1. A turbine blade fixed to the shaft, A housing that accommodates the turbine blade and the shaft, and rotatably supports the shaft, A nozzle ring, which is housed in the aforementioned housing and positioned radially outward from the turbine blade, A plurality of nozzle vanes are attached to the nozzle ring so as to be arranged along the circumferential direction of the nozzle ring, A first elastic member biases the nozzle ring relative to the housing in the axial direction of the shaft, The nozzle ring is positioned in the circumferential direction relative to the housing, and the positioning unit is provided for this purpose. The positioning unit is A positioning pin is provided on one of the housing and the nozzle ring, and extends in the axial direction. A first engaging portion is provided on the other side of the housing and the nozzle ring, which engages with the positioning pin, A second elastic member biases the nozzle ring so as to restrain it circumferentially with respect to the housing, It comprises a second engaging portion that engages with the second elastic member, The second elastic member and the second engaging portion are provided on at least one of the housing and the nozzle ring. The first engaging portion comprises a first inner surface that abuts the positioning pin in the circumferential direction, and a second inner surface that faces the first inner surface in the circumferential direction and has a gap between it and the positioning pin. A supercharger in which the second elastic member biases the nozzle ring in the circumferential direction such that the positioning pin remains in contact with the first inner surface.

2. The positioning pin is provided in the housing, The supercharger according to claim 1, wherein the first engaging portion is provided on the nozzle ring.

3. The supercharger according to claim 2, wherein the second elastic member is attached to the housing so as to be arranged in the circumferential direction with respect to the positioning pin, and biases the nozzle ring in the circumferential direction.

4. The housing has an inner circumferential surface facing the nozzle ring in the axial direction, The supercharger according to claim 2, wherein the second elastic member is attached to the inner circumferential surface of the housing and biases the nozzle ring in the circumferential direction.

5. A turbine blade fixed to a shaft, A housing that accommodates the turbine blade and the shaft, and rotatably supports the shaft, A nozzle ring, which is housed in the aforementioned housing and positioned radially outward from the turbine blade, A plurality of nozzle vanes are attached to the nozzle ring so as to be arranged along the circumferential direction of the nozzle ring, A first elastic member biases the nozzle ring relative to the housing in the axial direction of the shaft, The nozzle ring is positioned in the circumferential direction relative to the housing, and the positioning unit is provided for this purpose. The positioning unit is A positioning pin provided in the housing and extending in the axial direction, The nozzle ring is provided with a first engaging portion that engages with the positioning pin, A second elastic member biases the nozzle ring so as to restrain it circumferentially with respect to the housing, The second engaging portion engages with the second elastic member, and the assembly comprises The second elastic member and the second engaging portion are provided on at least one of the housing and the nozzle ring. The housing has an inner circumferential surface facing the nozzle ring in the axial direction, The second elastic member is attached to the inner circumferential surface of the housing and biases the nozzle ring in a direction intersecting the axial direction and the radial direction of the nozzle ring. The nozzle ring has an outer peripheral surface that faces the housing in the radial direction of the nozzle ring, The second engaging portion is provided on the nozzle ring such that an opening is formed on the outer circumferential surface of the nozzle ring, and is a notch having a tapered surface. The second elastic member biases the tapered surface radially inward of the nozzle ring, and is a supercharger.

6. A turbine blade fixed to a shaft, A housing that accommodates the turbine blade and the shaft, and rotatably supports the shaft, A nozzle ring, which is housed in the aforementioned housing and positioned radially outward from the turbine blade, A plurality of nozzle vanes are attached to the nozzle ring so as to be arranged along the circumferential direction of the nozzle ring, A first elastic member biases the nozzle ring relative to the housing in the axial direction of the shaft, The nozzle ring is positioned in the circumferential direction relative to the housing, and the positioning unit is provided for this purpose. The positioning unit is A positioning pin provided in the housing and extending in the axial direction, The nozzle ring is provided with a first engaging portion that engages with the positioning pin, A second elastic member biases the nozzle ring so as to restrain it in the circumferential direction relative to the housing, The second engaging portion engages with the second elastic member, and the assembly comprises The second elastic member and the second engaging portion are provided on at least one of the housing and the nozzle ring. The housing has an inner circumferential surface facing the nozzle ring in the axial direction, The second elastic member is attached to the inner circumferential surface of the housing and biases the nozzle ring in a direction intersecting the axial direction and the radial direction of the nozzle ring. The nozzle ring has an outer peripheral surface that faces the housing in the radial direction of the nozzle ring, The second engagement portion is provided on the nozzle ring such that an opening is formed on the outer circumferential surface of the nozzle ring, and is a notch having two inner surfaces facing each other in the circumferential direction of the nozzle ring. The second elastic member is a supercharger that biases one of the two inner surfaces.

7. A turbine blade fixed to the shaft, A housing for the turbine blade, A nozzle ring, which is housed in the aforementioned housing and positioned radially outward from the turbine blade, Multiple nozzle vanes attached to the nozzle ring, The system includes a positioning unit for positioning the nozzle ring relative to the housing, The positioning unit is A positioning pin is provided on at least one of the housing and the nozzle ring, and extends in the axial direction of the shaft, A pin engagement portion that engages with the positioning pin to position the nozzle ring relative to the housing in the circumferential direction of the nozzle ring, The nozzle ring comprises an elastic body that biases the nozzle ring to restrain it in the circumferential direction relative to the housing, The pin engagement portion comprises a first inner surface that abuts the positioning pin in the circumferential direction, and a second inner surface that faces the first inner surface in the circumferential direction and has a gap between it and the positioning pin. A supercharger in which the elastic body biases the nozzle ring in the circumferential direction such that the positioning pin is in contact with the first inner surface.

8. The supercharger according to claim 7, further comprising an elastic engagement portion provided on at least one of the housing and the nozzle ring, which engages with the elastic body.

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