Turbines and turbochargers

Abstract

This turbine comprises: a first housing that has a scroll passage; a first platelike member that includes an annular first plate; a second platelike member that includes an annular second plate forming a gas passage between the first plate and the second plate; a second housing that has a facing surface facing the back surface, of the first plate, on a side opposite to the gas passage across a first space; an annular member that is disposed in the first space and that rotates with respect to the first platelike member; a link member coupled at one end to the annular member and coupled at the other end to a variable nozzle vane; a positioning pin fitted at one end in a first hole formed in the back surface of the first plate and fitted at the other end in a second hole formed in the facing surface of the second housing; and a stopper configured such that a first gap is formed between the facing surface, or the first plate, and the stopper, and the first gap is smaller than a second gap between the annular member and the facing surface, and than a third gap between the link member and the facing surface.

Description

[Technical Field]

[0001] The present disclosure relates to turbines and turbochargers. [Background technology]

[0002] Known turbochargers (superchargers) that supercharge the intake air of an internal combustion engine by utilizing the energy of the exhaust gas from the engine include those equipped with variable geometry turbines (see, for example, Patent Document 1). A variable geometry turbine has a plurality of nozzle vanes arranged in the circumferential direction of the turbine wheel in an exhaust gas passage that sends exhaust gas from the turbine's scroll passage to the turbine wheel, and the blade angle of these nozzle vanes can be changed externally by an actuator to adjust the flow path cross-sectional area of ​​the exhaust gas passage (the flow path between adjacent nozzle vanes). A variable geometry turbine adjusts the flow path cross-sectional area of ​​the exhaust gas passage to change the flow velocity and pressure of the exhaust gas introduced to the turbine wheel, thereby enhancing the supercharging effect.

[0003] Patent Document 1 discloses that two plate-like members (nozzle mount, nozzle plate) that form an exhaust gas flow path are connected via a nozzle support, and that a press-fit pin (positioning pin) for positioning the nozzle mount and the bearing housing is press-fit into a press-fit hole formed in the nozzle mount. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2013-072401 Summary of the Invention [Problem to be solved by the invention]

[0005] When the variable geometry turbine is in operation, thermal deformation causes the nozzle mount to move closer to the bearing housing, causing the press-fit pin to be inserted excessively into the press-fit hole, increasing the frictional resistance between the press-fit pin and the press-fit hole, which could result in the press-fit pin becoming stuck in the press-fit hole.If the press-fit pin becomes stuck in the press-fit hole, the holding structure for the variable nozzle mechanism cannot be maintained, and the variable nozzle mechanism may float, exposing it to risks such as wear due to vibration.

[0006] In view of the above circumstances, at least one embodiment of the present disclosure aims to provide a turbine and a turbocharger that can stably maintain the holding structure of the variable nozzle unit by suppressing sticking of the positioning pins. [Means for solving the problem]

[0007] A turbine according to at least one embodiment of the present disclosure comprises: a first housing having a scroll flow passage; a turbine wheel provided on the inner circumferential side of the scroll flow passage; a first plate-shaped member including an annular first plate portion; a second plate-shaped member including an annular second plate portion disposed opposite the first plate portion and forming a gas flow path from the scroll flow path toward the turbine wheel between the first plate portion and the second plate portion; at least one variable nozzle vane disposed in the gas flow path; a second housing having an opposing surface that faces a back surface of the first plate portion opposite to a flow path wall surface that faces the gas flow path, with a first space interposed between the second housing and the back surface; an annular member disposed in the first space and configured to rotate relative to the first plate-shaped member by an external driving force; at least one link member having one end connected to the annular member and the other end connected to the variable nozzle vane, the at least one link member changing a blade angle of the variable nozzle vane connected to the other end in conjunction with rotation of the annular member; a biasing member disposed between the second housing and the first plate-shaped member and configured to bias the first plate portion toward the gas flow path; at least one positioning pin, one end of which is fitted into a first hole formed in the rear surface of the first plate portion and the other end of which is fitted into a second hole formed in the opposing surface of the second housing; The at least one stopper portion is provided on the opposing surface or the first plate portion, and a first gap is formed between the stopper portion and the opposing surface or between the stopper portion and the first plate portion, and the first gap is configured to be smaller than a second gap between the annular member and the opposing surface and a third gap between the at least one link member and the opposing surface.

[0008] A turbocharger according to at least one embodiment of the present disclosure includes: the turbine; a centrifugal compressor configured to be driven by the turbine. [Effects of the Invention]

[0009] According to at least one embodiment of the present disclosure, a turbine and a turbocharger are provided that can stably maintain the holding structure of the variable nozzle unit by suppressing sticking of the positioning pins. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a schematic diagram of an internal combustion engine system including a turbocharger according to an embodiment; [Figure 2] 1 is a schematic cross-sectional view of an embodiment of a turbine taken along an axis thereof; [Figure 3] FIG. 2 is a schematic diagram of a variable nozzle unit included in a turbine according to an embodiment. [Figure 4] 1 is a schematic cross-sectional view showing a cross section along an axis line on one side of an axis line of a turbine according to an embodiment. [Figure 5]1 is a schematic cross-sectional view showing a cross section along an axis line on one side of an axis line of a turbine according to an embodiment. [Figure 6] 1 is a schematic cross-sectional view showing a cross section along an axis line on one side of an axis line of a turbine according to an embodiment. [Figure 7] 1 is a schematic cross-sectional view showing a cross section along an axis line on one side of an axis line of a turbine according to an embodiment. [Figure 8] FIG. 10 is an explanatory diagram for explaining the tongue-proximal side and the tongue-distal side. [Figure 9] FIG. 2 is a schematic diagram of a variable nozzle unit included in a turbine according to an embodiment. [Figure 10] 1 is a schematic cross-sectional view showing a cross section along an axis line on one side of an axis line of a turbine according to an embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, several embodiments of the present disclosure will be described with reference to the accompanying drawings. However, the dimensions, materials, shapes, relative arrangements, etc. of components described as embodiments or shown in the drawings are merely illustrative examples and are not intended to limit the scope of the present disclosure.

[0012] (Turbocharger) FIG. 1 is a schematic diagram of an internal combustion engine system 10 including a turbocharger 1 according to one embodiment. A turbine 2 according to the present disclosure can be mounted on, for example, a turbocharger (supercharger) 1 for automobiles, ships, or industrial applications (e.g., land-based power generation). In the following embodiments, a turbine 2 mounted on a turbocharger 1 will be described as an example, but the turbine 2 according to the present disclosure is not limited to being mounted on a turbocharger 1. Furthermore, the working fluid of the turbine 2 does not need to be limited to exhaust gas. In other words, the turbine 2 according to the present disclosure may be configured as a standalone turbine 2, or may be configured in combination with a mechanism or device other than a centrifugal compressor 12, as long as it is capable of converting working fluid energy into mechanical power (e.g., rotational force). Furthermore, the use of the turbine 2 does not need to be limited.

[0013] 1, a turbocharger 1 according to some embodiments is configured to compress a fluid (e.g., air) by being driven by the energy of exhaust gas discharged from an internal combustion engine (engine) 11. The turbocharger 1 includes a turbine 2 and a centrifugal compressor 12 configured to be driven by the turbine 2.

[0014] The centrifugal compressor 12 includes an impeller 13 and a compressor housing 14 configured to rotatably accommodate the impeller 13. The turbine 2 includes at least a turbine wheel 3, a first housing (turbine housing) 4, and a second housing (bearing housing) 5 configured to rotatably accommodate the turbine wheel 3 between the first housing 4 and the second housing 4.

[0015] 1, the turbocharger 1 further includes a rotating shaft 15 having a turbine wheel 3 connected to one end thereof and an impeller 13 connected to the other end thereof, and a bearing 16 configured to rotatably support the rotating shaft 15 between the turbine wheel 3 and the impeller 13. The second housing 5 is disposed between the first housing 4 and the compressor housing 14, and is connected to each of the first housing 4 and the compressor housing 14 via fastening members (not shown), such as bolts and nuts. The second housing 5 may be configured to accommodate the bearing 16.

[0016] The turbine 2 of the turbocharger 1 is configured to rotate a turbine wheel 3 using the energy of exhaust gas discharged from an internal combustion engine 11. The impeller 13 is coaxially connected to the turbine wheel 3 via a rotary shaft 15, and is therefore driven to rotate about an axis LA in conjunction with the rotation of the turbine wheel 3. The centrifugal compressor 12 of the turbocharger 1 is configured to drive the impeller 13 to rotate about an axis LA, thereby drawing air (intake air, gas) into a compressor housing 14, compressing the air, and sending the compressed air to the internal combustion engine 11.

[0017] The compressed air sent from the centrifugal compressor 12 to the internal combustion engine 11 is used for combustion in the internal combustion engine 11. Exhaust gas generated by combustion in the internal combustion engine 11 is sent from the internal combustion engine 11 to the turbine 2, causing the turbine wheel 3 to rotate.

[0018] (impeller) 1, the impeller 13 is connected to the other end of the rotary shaft 15 and is therefore rotatable integrally with the rotary shaft 15 around the axis of the impeller 13. The impeller 13 is configured to guide air introduced along the axial direction of the impeller 13 to the outside in the radial direction of the impeller 13. In the illustrated embodiment, the impeller 13 is an open-type impeller that does not include an annular member surrounding the outer periphery of the blades of the impeller 13.

[0019] (Compressor housing) A gas introduction passage 141 and a scroll passage 142 are formed inside the compressor housing 14. In other words, the compressor housing 14 has the gas introduction passage 141 and the scroll passage 142.

[0020] The gas introduction passage 141 is a passage for taking in air (gas) from outside the compressor housing 14 (centrifugal compressor 12) and guiding the taken-in air to the impeller 13. The gas introduction passage 141 is provided on one side of the impeller 13 in the axial direction of the impeller 13, and extends along the axial direction of the impeller 13. By driving the impeller 13 to rotate, air is taken in from outside the compressor housing 14 into the gas introduction passage 141, and the taken-in air flows through the gas introduction passage 141 toward the impeller 13 and is guided to the impeller 13.

[0021] The scroll passage 142 is provided on the outer periphery of the impeller 13 and is a spiral passage extending along the circumferential direction of the impeller 13. Air that passes through the impeller 13 and is compressed by the impeller 13 is guided to the scroll passage 142. The compressed air that has passed through the scroll passage 142 is guided to the internal combustion engine 11.

[0022] 2 is a schematic cross-sectional view taken along the axis LA of the turbine 2 according to one embodiment. Hereinafter, the direction in which the axis LA of the turbine wheel 3 extends will be referred to as the axial direction of the turbine wheel 3, the direction perpendicular to the axis LA will be referred to as the radial direction of the turbine wheel 3, and the circumferential direction around the axis LA will be referred to as the circumferential direction of the turbine wheel 3. Hereinafter, the side of the turbine wheel 3 where the first housing 4 is located relative to the second housing 5 in the axial direction (the right side in FIG. 2) will be defined as the front side, and the side where the second housing 5 is located relative to the first housing 4 (the side opposite to the front side, left side in FIG. 2) will be defined as the rear side.

[0023] (turbine wheel) 2, the turbine wheel 3 includes a hub 31 having a substantially truncated cone shape and a plurality of turbine blades 32 provided on the outer peripheral surface of the hub 31. The plurality of turbine blades 32 are arranged at intervals from one another in the circumferential direction about the axis LA. The hub 31 and the plurality of turbine blades 32 are provided so as to be rotatable integrally with the rotating shaft 15 about the axis LA. The turbine wheel 3 is configured to guide exhaust gas introduced from the outside in the radial direction of the turbine wheel 3 to the front side of the turbine wheel 3 along the axial direction of the turbine wheel 3.

[0024] (Scroll flow path, exhaust gas discharge flow path) A scroll passage 41 for guiding exhaust gas discharged from the internal combustion engine 11 to the turbine wheel 3 and an exhaust gas discharge passage 42 for discharging exhaust gas that has passed through the turbine wheel 3 to the outside of the first housing 4 (turbine 2) are formed inside the first housing 4. In other words, the first housing 4 has the scroll passage 41 and the exhaust gas discharge passage 42. The scroll passage 41 is provided on the outer periphery of the turbine wheel 3 and is a spiral passage that extends along the circumferential direction of the turbine wheel 3. The exhaust gas discharge passage 42 extends forward from the turbine wheel 3 along the axial direction of the turbine wheel 3.

[0025] By fastening the first housing 4 and the second housing 5 together, an internal space 43 is formed between the first housing 4 and the second housing 5, connecting the scroll passage 41 and the exhaust gas discharge passage 42. A turbine wheel 3 is housed in this internal space 43 so as to be rotatable relative to the first housing 4 and the second housing 5. The turbine wheel 3 is provided on the inner peripheral side of the scroll passage 41.

[0026] The exhaust gas discharged from the internal combustion engine 11 is guided to the turbine wheel 3 via the scroll passage 41, and rotates the turbine wheel 3. The exhaust gas that has rotated the turbine wheel 3 is discharged to the outside of the first housing 4 (turbine 2) via the exhaust gas discharge passage 42.

[0027] (Variable nozzle unit) Fig. 3 is a schematic diagram of a variable nozzle unit 6 included in a turbine 2 according to one embodiment. As shown in Fig. 2, the turbine 2 further includes a variable nozzle unit 6 housed on the outer circumferential side of the turbine wheel 3 in the internal space 43 described above. The variable nozzle unit 6 forms a gas flow path (exhaust gas flow path) 43A for guiding exhaust gas from the scroll flow path 41 to the turbine wheel 3, and also serves to adjust the flow of exhaust gas in the gas flow path 43A. The gas flow path 43A is part of the internal space 43. The gas flow path 43A is formed between the scroll flow path 41 and the turbine wheel 3 so as to surround the periphery (radial outside) of the turbine wheel 3.

[0028] As shown in FIG. 2, the variable nozzle unit 6 includes a first plate-shaped member (nozzle mount) 7, a second plate-shaped member (nozzle plate) 8, at least one (multiple in the illustrated example) variable nozzle vane 61, an annular member (drive ring) 62, and at least one (multiple in the illustrated example) link member (lever plate) 63.

[0029] (First plate-shaped member) The first plate-shaped member (nozzle mount) 7 includes an annular first plate portion 71 that extends along the circumferential direction of the turbine wheel 3 on the outer periphery of the turbine wheel 3. A first flow path wall surface 72 that faces the gas flow path 43A is formed on the front side of the first plate portion 71, and a back surface 73 is formed on the rear side of the first plate portion 71, i.e., on the side opposite to the first flow path wall surface 72.

[0030] (Second plate-shaped member) The second plate-shaped member (nozzle plate) 8 is disposed opposite the first plate portion 71 and includes an annular second plate portion 81 that forms a gas flow path 43A from the scroll flow path 41 toward the turbine wheel 3 between the first plate portion and the second plate portion 81. The second plate portion 81 is disposed forward of the first plate portion 71 and extends along the circumferential direction of the turbine wheel 3 on the outer periphery of the turbine wheel 3. A second flow path wall surface 82 that faces the gas flow path 43A is formed on the rear side of the second plate portion 81.

[0031] The gas flow path 43A is formed between the first flow path wall surface 72 and the second flow path wall surface 82. The first flow path wall surface 72 is located rearward of the second flow path wall surface 82 and faces the second flow path wall surface 82. The exhaust gas introduced into the turbine 2 passes through the scroll flow path 41 and then the gas flow path 43A, and is then led to the turbine wheel 3 to rotate the turbine wheel 3.

[0032] (support member) 2, the variable nozzle unit 6 may further include at least one (e.g., a plurality) support members (nozzle supports) 64 that support the first plate member 7 and the second plate member 8 while spaced apart from each other. The plurality of support members 64 are arranged at intervals in the circumferential direction of the turbine wheel 3. One side of each of the plurality of support members 64 is fixed to the first plate portion 71, and the other side is fixed to the second plate portion 81. The second plate member 8 is supported by the support member 64 while being spaced forward from the first plate member 7.

[0033] (1st space) The second housing 5 has an opposing surface 51 that faces the back surface 73 of the first plate portion 71, with the first space 43B sandwiched between the opposing surface 51 and the back surface 73 of the first plate portion 71. The first space 43B is a part of the internal space 43, and is formed on the opposite side of the first plate portion 71 from the gas flow path 43A.

[0034] (Variable nozzle vane) Each of the variable nozzle vanes 61 is disposed in the gas flow path 43A and supported by a first plate portion 71 (first plate-shaped member 7) so as to be rotatable about its own center of rotation RC. The variable nozzle vanes 61 are disposed at intervals in the circumferential direction of the turbine wheel 3.

[0035] (Annular member) The annular member (drive ring) 62 is disposed in the first space 43B, and configured to rotate about an axis LB of the annular member 62 (variable nozzle unit 6) relative to the first plate-like member 7 by an external driving force.

[0036] (Drive mechanism, control device) 2, the turbine 2 further includes a drive mechanism (actuator) 65 configured to transmit a drive force to the annular member 62 to rotate the annular member 62 about its axis LB, and a control device (controller) 66 configured to control the rotation of the annular member 62 about the axis LB. The drive mechanism 65 includes an electric motor that generates the drive force, an air cylinder that transmits the drive force, and the like.

[0037] (Link member) 3, the variable nozzle unit 6 includes link members (lever plates) 63 in the same number as the variable nozzle vanes 61. Each of the multiple link members 63 is arranged in the first space 43B, has one end 631 connected to the annular member 62, and has the other end 632 connected to the variable nozzle vane 61, and is configured to change the blade angle of the variable nozzle vane 61 connected to the other end 632 in conjunction with the rotation of the annular member 62.

[0038] In the embodiment shown in FIG. 3 , one end 631 of each link member 63 includes a fitting portion 631A that fits into a fitting portion 621 formed in the annular member 62. The fitting portion 621 includes a groove 621A formed in the outer circumferential edge of the annular member 62, and the fitting portion 631A is accommodated inside the groove 621A and is adapted to loosely fit into the groove 621A. The first plate portion 71 has a plurality of through holes 74 that penetrate the first flow path wall surface 72 and the back surface 73. The plurality of through holes 74 are arranged at intervals in the circumferential direction of the turbine wheel 3. The first plate portion 71 has the same number of through holes 74 as the number of variable nozzle vanes 61 and link members 63. The other end of each link member 63 is inserted through the through hole 74 that individually corresponds to the link member 63, and is connected to the variable nozzle vane 61 individually corresponding to the link member 63.

[0039] When the annular member 62 is rotated to one side in the circumferential direction of the turbine wheel 3, the variable nozzle vanes 61 adjacent to each other in the circumferential direction move (rotate) in directions away from each other, increasing the flow path cross-sectional area of ​​the gas flow path 43A between the variable nozzle vanes 61. When the annular member 62 is rotated to the other side in the circumferential direction of the turbine wheel 3, the variable nozzle vanes 61 adjacent to each other in the circumferential direction move (rotate) in directions approaching each other, decreasing the flow path cross-sectional area of ​​the gas flow path 43A between the variable nozzle vanes 61.

[0040] The variable nozzle unit 6 rotates the variable nozzle vanes 61 about their respective rotation centers RC by transmitting a driving force from outside the variable nozzle unit 6 (drive mechanism 65) to the variable nozzle vanes 61 via an annular member 62 and multiple link members 63, thereby changing the blade angle of each. The turbine 2 can change the flow velocity and pressure of the exhaust gas guided to the turbine wheel 3 by increasing or decreasing the flow path cross-sectional area of ​​the gas path 43A using the variable nozzle unit 6, thereby controlling the boost pressure of the turbine 2.

[0041] (biasing member) 4 is a schematic cross-sectional view showing a cross section along the axis LA on one side of the axis LA of the turbine 2 according to one embodiment. As shown in FIG. 4, the turbine 2 further includes a biasing member 21 that is disposed between the second housing 5 and the first plate-shaped member 7 and configured to bias the first plate portion 71 toward the gas flow path 43A.

[0042] 4, the biasing member 21 includes a disc spring 21A that abuts against an end surface 52 formed radially inward from the opposing surface 51 of the second housing 5, and an end surface 75A of the inner peripheral edge portion 75 of the first plate portion 71 opposite to the first flow path wall surface 72. The end surface 75A is formed radially inward from the back surface 73. The disc spring 21A (biasing member 21) seals the gap between the end surface 52 of the second housing 5 and the end surface 75A of the first plate portion 71, thereby suppressing the inflow of exhaust gas from the back surface side of the turbine wheel 3 into the first space 43B.

[0043] The first housing 4 includes an engaged portion 44 that extends radially of the turbine wheel 3 and engages with an outer peripheral edge portion 76 of the first plate portion 71. The engaged portion 44 has a rear scroll passage wall surface 441 that extends radially outward from the rear end P1 of the scroll passage 41, and an engaged surface 442 that is located on the opposite side in the axial direction from the rear scroll passage wall surface 441 and faces the first space 43B.

[0044] When the first plate-shaped member 7 is biased forward by the biasing member 21, the outer peripheral edge 76 of the first plate portion 71 is pressed against the locked portion 44 of the first housing 4, and the front locking surface 76A of the outer peripheral edge 76 abuts against the locked surface 442. This seals the gap between the front locking surface 76A and the locked surface 442, thereby suppressing the inflow of exhaust gas from the scroll flow path 41 to the first space 43B. In the illustrated embodiment, the locking surface 76A is a stepped surface formed radially outward and rearward of the first flow path wall surface 72. Note that in some other embodiments, the outer peripheral edge 76 of the first plate portion 71 may be sandwiched between the first housing 4 and the second housing 5.

[0045] 4, the first housing 4 includes a front-side opposing surface 45 that faces the second back surface 83 of the second plate portion 81, and a shroud portion 46 that is radially inward of the second plate portion 81 and the front-side opposing surface 45 and protrudes rearward from the front-side opposing surface 45. The shroud portion 46 has a shroud surface 46A that is convexly curved to face the tip-side ends (tips) of the multiple turbine blades 32, and that forms a gap (clearance) between the shroud portion 46 and the tip-side ends.

[0046] (First embodiment) As shown in Fig. 4, the turbine 2 according to some embodiments includes at least the above-described turbine wheel 3, first housing 4, second housing 5, first plate-shaped member 7, second plate-shaped member 8, biasing member 21, at least one variable nozzle vane 61, an annular member 62, and at least one link member 63. As shown in Fig. 4, the turbine 2 further includes at least one positioning pin 9 and at least one stopper portion 22. Note that this embodiment can be implemented independently of other embodiments.

[0047] (locating pin) As shown in FIG. 4 , one end 91 of at least one positioning pin 9 is fitted (e.g., press-fit) into a first hole 77 formed in the back surface 73 of the first plate portion 71, and the other end 92 of the positioning pin 9 is fitted (e.g., press-fit) into a second hole 53 formed in the opposing surface 51 of the second housing 5. The positioning pin 9 is formed in a rod shape with its longitudinal direction along the axial direction of the turbine 2. The positioning pin 9 is made of, for example, a metal material. In order to improve the assembly of the turbine 2, by connecting the variable nozzle unit 6 to the second housing 5 via the positioning pin 9, it is possible to prevent the variable nozzle unit 6 from falling off from the second housing 5.

[0048] (Stopper part) At least one stopper portion 22 is provided on the opposing surface 51 or the first plate portion 71. As shown in FIG. 4 , the at least one stopper portion 22 may be configured integrally with the first plate portion 71, or may be configured integrally with the opposing surface 51. Alternatively, the at least one stopper portion 22 may be a separate member from the opposing surface 51 or the first plate portion 71, and may be attached to the opposing surface 51 or the first plate portion 71.

[0049] 4, the turbine 2 has a first gap G1 formed between the stopper portion 22 and the opposing surface 51 (illustrated example) or between the stopper portion 22 and the first plate portion 71. The first gap G1 is configured to be smaller than a second gap G2 between the annular member 62 and the opposing surface 51 and a third gap G3 between the opposing surface 51 and at least one link member 63.

[0050] According to the above configuration, the first plate-shaped member 7 tends to move closer to the second housing 5 due to thermal deformation during operation of the turbine 2, but the movement of the first plate-shaped member 7 toward the second housing 5 can be restricted by abutting the stopper portion 22 against the opposing surface 51 of the second housing 5 or the first plate portion 71. By restricting the movement of the first plate-shaped member 7 toward the second housing 5, it is possible to prevent the positioning pin 9 from being excessively inserted into the first hole 77 or the second hole 53 and becoming stuck in the first hole 77 or the second hole 53.

[0051] If the turbine 2 were not provided with stopper portion 22, there is a risk that thermal deformation during operation of the turbine 2 would cause the first plate-shaped member 7 to move closer to the second housing 5 than the first gap G1. In this case, the positioning pin 9 would be inserted excessively into the first hole 77 or the second hole 53, increasing the frictional resistance between the positioning pin 9 and the first hole 77 or the second hole 53. As a result, the reaction force of the biasing member 21 (the force that pushes the first plate-shaped member 7 back toward the gas flow path 43A) would not be able to maintain the holding structure of the variable nozzle unit 6, creating a gap between the outer peripheral edge portion 76 of the first plate-shaped member 7 and the locked portion 44 of the first housing 4, and the variable nozzle unit 6 might lift up in the first space 43B. In this case, there is a risk that the variable nozzle unit 6 would be exposed to risks such as wear due to vibration.

[0052] According to the above configuration, the stopper portion 22 described above limits the movement of the first plate-shaped member 7 toward the second housing 5, thereby preventing the positioning pin 9 from adhering to the first hole 77 or the second hole 53 and interfering with the reaction force of the biasing member 21. In this case, the reaction force of the biasing member 21 can stably maintain the holding structure of the variable nozzle unit 6 (first plate-shaped member 7). By stably maintaining the holding structure of the variable nozzle unit 6, the risk of wear due to vibration of the variable nozzle unit 6 can be reduced.

[0053] In some embodiments, the at least one stopper portion 22 described above is configured integrally with the first plate-shaped member 7. In this case, an increase in the number of parts can be suppressed, and the complexity of the structure of the turbine 2 can be suppressed, compared to when the stopper portion 22 is a separate member from the first plate-shaped member 7 or the second housing 5. Furthermore, when the stopper portion 22 is configured integrally with the second housing 5, there is a risk that the stopper portion 22 will interfere with the variable nozzle unit 6 when the variable nozzle unit 6 is assembled to the second housing 5. However, when the stopper portion 22 is configured integrally with the first plate-shaped member 7, this risk is relatively small. Furthermore, it is easier to form the stopper portion 22 on the first plate-shaped member 7 than on the second housing 5.

[0054] In some embodiments, as shown in FIGS. 3 and 4, the first plate-shaped member 7 includes a cylindrical portion 78 that protrudes from the back surface 73 of the first plate portion 71 and passes through the center hole of the annular member 62; and at least one claw portion 22A that protrudes from the cylindrical portion 78 radially outward beyond the inner peripheral edge of the annular member 62 and sandwiches the inner peripheral edge of the annular member 62 between itself and the back surface 73 of the first plate portion 71. The at least one stopper portion 22 described above includes at least one claw portion 22A. That is, the claw portion 22A of the first plate portion 71 is used as the stopper portion 22.

[0055] 3, the at least one claw portion 22A includes a plurality of (three in the illustrated example) claw portions 22A arranged at intervals along the circumferential direction of the turbine wheel 3. Recesses 622 are formed on the inner peripheral edge of the annular member 62, the number of which is the same as the number of claw portions 22A, and into which the claw portions 22A are passed when assembling the first plate-shaped member 7 and the annular member 62.

[0056] According to the above configuration, by using at least one claw portion 22A that clamps the inner peripheral edge of the annular member 62 as a stopper portion 22, it is not necessary to provide a new stopper portion protrusion on the first plate-shaped member 7, so that the number of changes to the existing shape of the first plate-shaped member 7 can be reduced, and the complexity of the structure of the first plate-shaped member 7 can be suppressed.

[0057] In the embodiment shown in FIGS. 4 and 5 , the second housing 5 described above has a protruding portion 54 that protrudes forward from the opposing surface 51 along the axial direction of the turbine wheel 3. The protruding portion 54 may be formed in an arc or annular shape extending along the circumferential direction of the turbine wheel 3. In the turbine 2, a fourth gap G4 is formed between an end face 54A of the protruding portion 54 on the front side in the axial direction and a back face 73 of the first plate portion 71. In the embodiment shown in FIGS. 4 and 5 , the protruding portion 54 (end face 54A) is a part of the opposing surface 51 and is formed radially inward from an outer peripheral edge portion of the opposing surface 51 where the protruding portion 54 is not formed, and is formed radially outward from the end face 52 described above. The back face 73 of the first plate portion 71 includes an inner peripheral back face 73A at its inner peripheral edge that forms the fourth gap G4 between the end face 54A and the end face 54A.

[0058] In the embodiment shown in FIG. 4, the fourth gap G4 is configured to be larger than the second gap G2 and the third gap G3.

[0059] In some embodiments, as shown in Fig. 5, the fourth gap G4 is configured to be smaller than the second gap G2 and the third gap G3. In this case, the protrusion 54 can be used as the stopper portion 22. That is, in the embodiment shown in Fig. 5, the at least one stopper portion 22 is the protrusion 54 that is integrally formed with the second housing 5. The fourth gap G4 becomes the first gap G1.

[0060] According to the above configuration, by using the protrusion 54 as the stopper portion 22, it is not necessary to provide a new stopper portion protrusion on the second housing 5, so that the number of changes to the existing shape of the second housing 5 can be reduced, and the complexity of the structure of the second housing 5 can be suppressed.

[0061] (Second embodiment) FIG. 5 is a schematic cross-sectional view showing a cross section of a turbine 2 according to one embodiment, taken along the axis LA on one side of the axis LA. As shown in FIG. 5, the turbine 2 according to some embodiments includes at least the turbine wheel 3, first housing 4, second housing 5, first plate-shaped member 7, second plate-shaped member 8, biasing member 21, and at least one variable nozzle vane 61 described above. As shown in FIG. 5, the turbine 2 further includes at least one positioning pin 9 and an adhesive layer 94. Note that this embodiment can be implemented independently of the other embodiments. For example, the turbine 2 does not need to include the stopper portion 22 described above.

[0062] (locating pin) As shown in FIG. 5 , one end 91 of at least one positioning pin 9 is inserted into a first hole 77 formed in the back surface 73 of the first plate portion 71, and the other end 92 of the positioning pin 9 is inserted into a second hole 53 formed in the opposing surface 51 of the second housing 5. At least one of the one end 91 and the other end 92 of the positioning pin 9 is inserted with a gap 93A, 93B formed therebetween. The positioning pin 9 is formed in a rod shape with its longitudinal direction along the axial direction of the turbine 2. The positioning pin 9 is made of, for example, a metal material. In the illustrated embodiment, the one end 91 of the positioning pin 9 is loosely inserted into the first hole 77, and a gap 93A is formed between the outer circumferential surface of the one end 91 and the inner circumferential surface of the first hole 77. The other end 92 of the positioning pin 9 is loosely inserted into the second hole 53, and a gap 93B is formed between the outer circumferential surface of the other end 92 and the inner circumferential surface of the second hole 53.

[0063] (adhesive layer) The adhesive layer 94 is interposed in at least one of the gaps 93A and 93B. In the illustrated embodiment, the adhesive layer 94 is interposed in both the gaps 93A and 93B. The adhesive layer 94 is configured so that its adhesive strength decreases due to heat input during operation of the turbine 2. The gap 93A is more affected by heat input during operation of the turbine 2 than the gap 93B. Therefore, when the adhesive layer 94 is interposed in either the gap 93A or the gap 93B, it is preferable to interpose it in the gap 93A. Note that the decrease in adhesive strength of the adhesive layer 94 may be temporary during operation of the turbine 2 or may be permanent. When the variable nozzle unit 6 is connected to the second housing 5 via the positioning pin 9 and the adhesive layer 94, the adhesive strength of the adhesive layer 94 is not decreased, and therefore, detachment of the variable nozzle unit 6 from the second housing 5 is prevented.

[0064] According to the above configuration, the adhesive strength of the adhesive layer 94 decreases due to heat input during operation of the turbine 2, creating a gap between the positioning pin 9 and at least one of the first hole 77 and the second hole 53. This prevents the positioning pin 9 from adhering to the first hole 77 or the second hole 53 when the first plate-shaped member 7 approaches the second housing 5 due to thermal deformation during operation of the turbine 2. By preventing the positioning pin 9 from adhering to the first hole 77 or the second hole 53 and interfering with the reaction force of the biasing member 21, the reaction force of the biasing member 21 can stably maintain the holding structure of the variable nozzle unit 6 (first plate-shaped member 7). Maintaining a stable holding structure for the variable nozzle unit 6 reduces the risk of wear due to vibration of the variable nozzle unit 6.

[0065] In some embodiments, the adhesive layer 94 is made of a thermoplastic resin material, which may include, for example, at least one of a phenoxy resin, a polyurethane resin, a polyester urethane resin, a butyral resin, an acrylic resin, a polyimide resin, and a polyamide resin.

[0066] According to the above configuration, the adhesive layer 94 made of a thermoplastic resin material is softened (e.g., liquefied) by the heat input during operation of the turbine 2, thereby reducing the adhesive strength of the adhesive layer 94 and effectively creating gaps 93A, 93B between at least one of the first hole 77 or the second hole 53 and the positioning pin 9.

[0067] (Third embodiment) FIG. 6 is a schematic cross-sectional view showing a cross section of a turbine 2 according to one embodiment, taken along the axis LA on one side of the axis LA. As shown in FIG. 6, the turbine 2 according to some embodiments includes at least the turbine wheel 3, first housing 4, second housing 5, first plate-shaped member 7, second plate-shaped member 8, biasing member 21, and at least one variable nozzle vane 61 described above. As shown in FIG. 6, the turbine 2 further includes at least one positioning pin 9 and a sliding layer 95. Note that this embodiment can be implemented independently of the other embodiments. For example, the turbine 2 does not need to include the stopper portion 22 described above.

[0068] (locating pin) 6, one end 91 of at least one positioning pin 9 is inserted into a first hole 77 formed in the back surface 73 of the first plate portion 71, and the other end 92 of the positioning pin 9 is inserted into a second hole 53 formed in the opposing surface 51 of the second housing 5. The positioning pin 9 is formed in a rod shape with its longitudinal direction aligned with the axial direction of the turbine 2. The positioning pin 9 is made of, for example, a metal material.

[0069] (sliding layer) The sliding layer 95 includes a solid lubricant that covers at least one of the outer peripheral surface 911 of one end 91 of at least one positioning pin 9, the outer peripheral surface 921 of the other end 92 of at least one positioning pin 9, the inner peripheral surface 771 of the first hole 77, or the inner peripheral surface 531 of the second hole 53. The sliding layer 95 may be formed by applying or coating a solid lubricant to an object such as the outer peripheral surfaces 911, 921 of the positioning pin 9, the inner peripheral surface 771 of the first hole 77, or the inner peripheral surface 531 of the second hole 53. The solid lubricant may include at least one of molybdenum disulfide, graphite, and polytetrafluoroethylene (PTFE).

[0070] In the illustrated embodiment, the sliding layer 95 includes a first-hole-side sliding layer 95A covering at least one of the outer peripheral surface 911 of one end 91 of the positioning pin 9 or the inner peripheral surface 771 of the first hole 77, and a second-hole-side sliding layer 95B covering at least one of the outer peripheral surface 921 of the other end 92 of the positioning pin 9 or the inner peripheral surface 531 of the second hole 53. The sliding layer 95 may be provided over the entire length of the positioning pin 9. The first-hole-side sliding layer 95A reduces frictional resistance between the outer peripheral surface 911 of the one end 91 of the positioning pin 9 and the inner peripheral surface 771 of the first hole 77. The second-hole-side sliding layer 95B reduces frictional resistance between the outer peripheral surface 921 of the other end 92 of the positioning pin 9 and the inner peripheral surface 531 of the second hole 53.

[0071] According to the above configuration, the sliding layer 95 reduces frictional resistance between the positioning pin 9 and at least one of the first hole 77 and the second hole 53, thereby preventing the positioning pin 9 from adhering to the first hole 77 or the second hole 53 when the first plate-shaped member 7 approaches the second housing 5 due to thermal deformation during operation of the turbine 2. By preventing the positioning pin 9 from adhering to the first hole 77 or the second hole 53 and interfering with the reaction force of the biasing member 21, the reaction force of the biasing member 21 can stably maintain the holding structure for the variable nozzle unit 6 and the first plate-shaped member 7. Maintaining a stable holding structure for the variable nozzle unit 6 reduces the risk of wear due to vibration of the variable nozzle unit 6.

[0072] Fig. 7 is a schematic cross-sectional view showing a cross section along the axis LA on one side of the axis LA of the turbine 2 according to one embodiment. Fig. 8 is an explanatory view for explaining the tongue-proximal side S1 and the tongue-distant side S2. Fig. 9 is a schematic view of the variable nozzle unit 6 included in the turbine 2 according to one embodiment. In some embodiments, as shown in Fig. 9, at least one of the first hole 77 and the second hole 53 has a longitudinal direction along the radial direction of the turbine wheel 3.

[0073] The first plate portion 71 in which the first hole 77 is formed and the second housing 5 in which the second hole 53 is formed have different amounts of thermal expansion when the turbine 2 is in operation, and a shear force due to the difference in thermal expansion between the first plate portion 71 and the second housing 5 acts on the positioning pin 9.

[0074] According to the above configuration, by making the hole shape of the first hole 77 or the second hole 53 have a longitudinal direction along the radial direction of the turbine wheel 3, the positioning pin 9 does not restrict thermal expansion between the first plate portion 71 and the second housing 5, as compared to when the first hole 77 or the second hole 53 is a round hole (see FIG. 3 ). This makes it possible to prevent excessive load from being generated between the positioning pin 9 and the first hole 77 or between the positioning pin 9 and the second hole 53, thereby effectively preventing the positioning pin 9 from adhering to the first hole 77 or the second hole 53. Furthermore, according to the above configuration, it is possible to reduce the shear force acting on the positioning pin 9 due to the difference in thermal expansion between the first plate portion 71 and the second housing 5, which also effectively prevents the positioning pin 9 from adhering to the first hole 77 or the second hole 53.

[0075] 7, the second plate-shaped member 8 may include the second plate portion 81 described above, a shroud surface 84 formed on an inner peripheral end of the second plate portion 81, and a tubular portion 85 protruding forward from the inner peripheral end of the second plate portion 81 along the axial direction of the turbine wheel 3. The shroud surface 84 is convexly curved to face the tip ends (tips) of the plurality of turbine blades 32, and a gap (clearance) is formed between the shroud surface 84 and the tip ends. The first housing 4 may include a front-side facing surface 45 facing the second back surface 83 of the second plate portion 81, and a step portion 47 continuing from the inner peripheral end of the front-side facing surface 45 and accommodating the tubular portion 85 of the second plate-shaped member 8.

[0076] 8, the tongue portion 48 of the scroll passage 41 is formed between the start and end of the winding of the scroll passage 41. As shown in Fig. 8, in a cross section perpendicular to the axial direction of the turbine wheel 3, a first reference line that is a straight line passing through the axis LA of the turbine wheel 3 and the tongue portion 48 is defined as BL1, and a second reference line that is a straight line passing through the axis LA of the turbine wheel 3 and perpendicular to the first reference line BL1 is defined as BL2. The side on which the tongue portion 48 is located with respect to the second reference line BL2 is defined as the tongue-near side S1, and the side away from the tongue portion 48 with respect to the second reference line BL2 is defined as the tongue-far side S2.

[0077] 9, the at least one positioning pin 9 described above includes a plurality of positioning pins 9 arranged at intervals along the circumferential direction of the turbine wheel 3. As shown in FIG. 9, in a cross section perpendicular to the axis LA of the turbine wheel 3, points CP that are equidistant from the respective center positions LD (e.g., centroids) of the plurality of positioning pins 9 are arranged shifted toward the tongue side (tongue-neighboring side S1) of the scroll passage 41 with respect to the axis LA of the turbine wheel 3.

[0078] The temperature of the gas flowing through the scroll passage 41 is higher on a tongue-near side S1, which is closer to the tongue 48 of the scroll passage 41 than the axis LA of the turbine wheel 3 of the variable nozzle unit 6, than on a tongue-far side S2, which is on the opposite side farther from the tongue 48 than the axis LA of the turbine wheel 3. For this reason, there is a large difference in the amount of thermal elongation due to heat input from the gas flowing through the scroll passage 41 between the tongue-near side S1 and the tongue-far side S2, and there is a risk that the amount of misalignment of the axis LB of the variable nozzle unit 6 with respect to the axis LA of the turbine wheel 3 will increase.

[0079] 4 and 7, if the axis LB of the variable nozzle unit 6 is misaligned with the axis LA of the turbine wheel 3, the inner peripheral end of the first plate-shaped member 7 may come into contact with the second housing 5. Also, in the embodiment shown in FIG. 7, the inner peripheral end of the second plate-shaped member 8 may come into contact with the turbine wheel 3.

[0080] According to the above configuration, by eccentrically positioning point CP (the center point between pins, the centroid) of the plurality of positioning pins 9 that is equidistant from each center position LD toward the tongue-near side S1 with respect to the axis LA of the turbine wheel 3, the positioning pin 9 on the tongue-near side S1 can suppress the thermal expansion on the tongue-near side S1 compared to when the center point CP is the same as the axis LA of the turbine wheel 3 or is eccentric toward the tongue-distant side S2. This reduces the difference in the amount of thermal expansion between the tongue-near side S1 and the tongue-distant side S2 and suppresses an increase in the amount of misalignment of the axis LB of the variable nozzle unit 6 with the axis LA of the turbine wheel 3. In this case, it is possible to suppress contact of the variable nozzle unit 6 with the first housing 4, the second housing 5, or the turbine wheel 3 due to misalignment of the axis LB of the variable nozzle unit 6 with the axis LA of the turbine wheel 3, and it is possible to suppress excessive contact loads from being applied to positioning due to this contact. By preventing excessive contact load from acting on the positioning, the positioning pin 9 can be effectively prevented from adhering to the first hole 77 or the second hole 53.

[0081] 10 is a schematic cross-sectional view showing a cross section along the axis LA on one side of the axis LA of the turbine 2 according to one embodiment. In some embodiments, as shown in Fig. 10, the above-mentioned urging member 21 (21B) includes at least a first urging plate portion 211 extending along the radial direction of the turbine wheel 3 and abutting against the second housing 5, and a second urging plate portion 212 extending along the radial direction and abutting against the first plate-shaped member 7.

[0082] In the illustrated embodiment, the first urging plate portion 211 and the second urging plate portion 212 are formed in an annular shape extending along the circumferential direction of the turbine wheel 3. The outer peripheral edge portion of the first urging plate portion 211 abuts against the end face 52 of the second housing 5 described above, and the outer peripheral edge portion of the second urging plate portion 212 abuts against the end face 75A of the first plate portion 71 described above. The urging member 21 (21B) has an opening facing outward in the radial direction of the turbine wheel 3. In the embodiment shown in FIG. 10, the urging member 21 (21B) has a V-shaped cross section.

[0083] According to the above configuration, the biasing member 21 (21B) including the first biasing plate portion 211 and the second biasing plate portion 212 can increase the pressing force (reaction force) on the first plate portion 71 compared to when a single plate member such as the disc spring 21A abuts against the second housing 5 and the first plate-shaped member 7. By increasing the pressing force (reaction force) on the first plate portion 71 by the biasing member 21 (21B), the holding structure of the variable nozzle unit 6 (first plate-shaped member 7) can be maintained more stably.

[0084] 1, a turbocharger 1 according to some embodiments includes the above-described turbine 2 and the above-described centrifugal compressor 12. In this case, the holding structure of the variable nozzle unit 6 (first plate-shaped member 7) can be stably maintained, and the risk of wear due to vibration of the variable nozzle unit 6 can be reduced, thereby improving the reliability of the turbocharger 1.

[0085] In this specification, expressions expressing relative or absolute arrangement such as "in a certain direction," "along a certain direction," "parallel," "orthogonal," "center," "concentric," or "coaxial" not only express such an arrangement strictly, but also express a state in which there is a relative displacement with a tolerance or an angle or distance to the extent that the same function is obtained. For example, expressions such as "identical," "equal," and "homogeneous" that indicate that something is in an equal state not only indicate a state of strict equality, but also indicate a state in which there is a tolerance or a difference to the extent that the same function is obtained. Furthermore, in this specification, expressions representing shapes such as a rectangular shape or a cylindrical shape not only represent rectangular shapes or cylindrical shapes in the strict geometric sense, but also represent shapes including uneven portions, chamfered portions, etc., to the extent that the same effect can be obtained. Furthermore, in this specification, the expressions "comprise," "include," or "have" a component are not exclusive expressions that exclude the presence of other components.

[0086] The present disclosure is not limited to the above-described embodiments, but also includes modifications to the above-described embodiments and appropriate combinations of these modifications.

[0087] The contents of the above-described embodiments can be understood, for example, as follows.

[0088] 1) A turbine (2) according to at least one embodiment of the present disclosure comprises: a first housing (4) having a scroll flow passage (41); a turbine wheel (3) provided on the inner circumferential side of the scroll flow passage (41); a first plate-shaped member (7) including an annular first plate portion (71); a second plate-shaped member (8) including an annular second plate portion (81) disposed opposite the first plate portion (71) and forming a gas flow path (43A) between the second plate portion (81) and the first plate portion (71) and extending from the scroll flow path (41) to the turbine wheel (3); at least one variable nozzle vane (61) disposed on the gas flow path (43A); a second housing (5) having an opposing surface (51) that faces a back surface (73) of the first plate portion (71) opposite to a flow path wall surface (72) facing the gas flow path (43A) with a first space (43B) interposed between the second housing (5) and a back surface (73) of the first plate portion (71); an annular member (62) disposed in the first space (43B) and configured to rotate relative to the first plate-shaped member (7) by an external driving force; at least one link member (63) having one end connected to the annular member (62) and the other end connected to the variable nozzle vane (61), the at least one link member (63) changing the blade angle of the variable nozzle vane (61) connected to the other end in conjunction with rotation of the annular member (62); an urging member (21) disposed between the second housing (5) and the first plate-shaped member (7) and configured to urge the first plate portion (71) toward the gas flow path (43A); at least one positioning pin (9) having one end (91) fitted into a first hole (77) formed in the back surface (73) of the first plate portion (71) and having the other end (92) fitted into a second hole (53) formed in the opposing surface (51) of the second housing (5); At least one stopper portion (22) is provided on the opposing surface (51) or the first plate portion (71), wherein a first gap (G1) is formed between the stopper portion (22) and the opposing surface (51) or between the stopper portion (22) and the first plate portion (71), and the first gap (G1) is configured to be smaller than a second gap (G2) between the annular member (62) and the opposing surface (51) and a third gap (G3) between the at least one link member (63) and the opposing surface (51).

[0089] According to the configuration 1), the first plate-shaped member 7 tends to move toward the second housing 5 due to thermal deformation during operation of the turbine 2. However, by bringing the stopper portion 22 into contact with the opposing surface 51 of the second housing 5 or the first plate portion 71, the movement of the first plate-shaped member 7 toward the second housing 5 can be restricted. By restricting the movement of the first plate-shaped member 7 toward the second housing 5, the positioning pin 9 can be prevented from being excessively inserted into the first hole 77 or the second hole 53 and becoming stuck in the first hole 77 or the second hole 53. By preventing the positioning pin 9 from becoming stuck in the first hole 77 or the second hole 53 and obstructing the reaction force of the biasing member 21, the reaction force of the biasing member 21 can be used to stably maintain the holding structure of the variable nozzle unit 6 and the first plate-shaped member 7. By stably maintaining the holding structure of the variable nozzle unit (6), the risk of wear due to vibration of the variable nozzle unit (6) can be reduced.

[0090] 2) In some embodiments, the turbine (2) according to 1) above, The at least one stopper portion (22) is formed integrally with the first plate-shaped member (7).

[0091] According to the configuration 2), an increase in the number of parts can be suppressed and the structure of the turbine (2) can be suppressed from becoming complicated, compared with the case where the stopper portion (22) is a separate member from the first plate-shaped member (7) or the second housing (5). Furthermore, if the stopper portion (22) is integrally formed with the second housing (5), there is a risk that the stopper portion (22) will interfere with the variable nozzle unit (6) when the variable nozzle unit (6) is assembled to the second housing (5). However, if the stopper portion (22) is integrally formed with the first plate-shaped member (7), this risk is relatively small. Furthermore, it is easier to form the stopper portion (22) on the first plate-shaped member (7) than on the second housing (5).

[0092] 3) In some embodiments, the turbine (2) according to 1) or 2) above, The first plate-shaped member (7) is a cylindrical portion (78) protruding from the back surface (73) of the first plate portion (71) and inserted through a center hole of the annular member (62); at least one claw portion (22A) protruding from the cylindrical portion (78) to an outer circumferential side beyond the inner circumferential edge of the annular member (62) and sandwiching the inner circumferential edge of the annular member (62) between the claw portion (22A) and the back surface (73) of the first plate portion (71); The at least one stopper portion (22) includes the at least one claw portion (22A).

[0093] According to the configuration of 3) above, by using at least one of the claw portions (22A) that clamp the inner peripheral edge of the annular member (62) as a stopper portion (22), it is not necessary to provide a new stopper portion (protrusion) on the first plate-shaped member (7). This reduces the number of changes to the existing shape of the first plate-shaped member (7), and prevents the structure of the first plate-shaped member (7) from becoming too complicated.

[0094] 4) The turbine (2) according to at least one embodiment of the present disclosure comprises: a first housing (4) having a scroll flow passage (41); a turbine wheel (3) provided on the inner circumferential side of the scroll flow passage (41); a first plate-shaped member (7) including an annular first plate portion (71); a second plate-shaped member (8) including an annular second plate portion (81) disposed opposite the first plate portion (71) and forming a gas flow path (43A) between the second plate portion (81) and the first plate portion (71) and extending from the scroll flow path (41) to the turbine wheel (3); at least one variable nozzle vane (61) disposed in the gas flow path (43A); a second housing (5) having an opposing surface (51) that faces a back surface (73) of the first plate portion (71) opposite to a flow path wall surface (72) facing the gas flow path (43A) with a first space (43B) interposed between the second housing (5) and a back surface (73) of the first plate portion (71); an urging member (21) disposed between the second housing (5) and the first plate-shaped member (7) and configured to urge the first plate portion (71) toward the gas flow path (43A); at least one positioning pin (9) having one end (91) inserted into a first hole (77) formed in the back surface (73) of the first plate portion (71) and the other end (92) inserted into a second hole (53) formed in the opposing surface (51) of the second housing (5), wherein at least one of the one end (91) and the other end (92) is inserted with a gap (93A, 93B) formed therebetween; and an adhesive layer (94) interposed in the gaps (93A, 93B), the adhesive layer (94) having adhesive strength reduced by heat input during operation of the turbine (2).

[0095] According to the configuration 4) above, heat input during operation of the turbine 2 reduces the adhesive strength of the adhesive layer 94, creating a gap between the positioning pin 9 and at least one of the first hole 77 and the second hole 53. This prevents the positioning pin 9 from adhering to the first hole 77 or the second hole 53 when the first plate-shaped member 7 approaches the second housing 5 due to thermal deformation during operation of the turbine 2. This prevents the positioning pin 9 from adhering to the first hole 77 or the second hole 53, preventing the reaction force of the biasing member 21 from being obstructed. This allows the reaction force of the biasing member 21 to stably maintain the holding structure of the variable nozzle unit 6 and the first plate-shaped member 7. Maintaining a stable holding structure for the variable nozzle unit 6 reduces the risk of wear due to vibration of the variable nozzle unit 6.

[0096] 5) In some embodiments, the turbine (2) according to 4) above, The adhesive layer (94) is made of a thermoplastic resin material.

[0097] According to the configuration of 5) above, the adhesive layer (94) made of a thermoplastic resin material is softened (e.g., liquefied) by heat input during operation of the turbine (2), thereby reducing the adhesive strength of the adhesive layer (94), and effectively creating a gap (93A, 93B) between at least one of the first hole (77) or the second hole (53) and the positioning pin (9).

[0098] 6) The turbine (2) according to at least one embodiment of the present disclosure comprises: a first housing (4) having a scroll flow passage (41); a turbine wheel (3) provided on the inner circumferential side of the scroll flow passage (41); a first plate-shaped member (7) including an annular first plate portion (71); a second plate-shaped member (8) including an annular second plate portion (81) disposed opposite the first plate portion (71) and forming a gas flow path (43A) between the second plate portion (81) and the first plate portion (71) and extending from the scroll flow path (41) to the turbine wheel (3); at least one variable nozzle vane (61) disposed in the gas flow path (43A); a second housing (5) having an opposing surface (51) that faces a back surface (73) of the first plate portion (71) opposite to a flow path wall surface (72) facing the gas flow path (43A) with a first space (43B) interposed between the second housing (5) and a back surface (73) of the first plate portion (71); an urging member (21) disposed between the second housing (5) and the first plate-shaped member (7) and configured to urge the first plate portion (71) toward the gas flow path (43A); at least one positioning pin (9) having one end (91) inserted into a first hole (77) formed in the back surface (73) of the first plate portion (71) and having the other end (92) inserted into a second hole (53) formed in the opposing surface (51) of the second housing (5); and a sliding layer (95) containing a solid lubricant that covers at least one of the outer peripheral surface (911) of the one end (91) of the at least one positioning pin (9), the outer peripheral surface (921) of the other end (92) of the at least one positioning pin (9), the inner peripheral surface (771) of the first hole (77), or the inner peripheral surface (531) of the second hole (53).

[0099] According to the configuration of 6), the sliding layer 95 reduces frictional resistance between the positioning pin 9 and at least one of the first hole 77 and the second hole 53. This prevents the positioning pin 9 from adhering to the first hole 77 or the second hole 53 when the first plate-shaped member 7 approaches the second housing 5 due to thermal deformation during operation of the turbine 2. This prevents the positioning pin 9 from adhering to the first hole 77 or the second hole 53 and hindering the reaction force of the biasing member 21. This prevents the positioning pin 9 from adhering to the first hole 77 or the second hole 53, thereby stably maintaining the holding structure of the variable nozzle unit 6 and the first plate-shaped member 7 using the reaction force of the biasing member 21. Maintaining a stable holding structure for the variable nozzle unit 6 reduces the risk of wear due to vibration of the variable nozzle unit 6.

[0100] 7) In some embodiments, the turbine (2) according to any one of 1) to 6) above, At least one of the first hole (77) and the second hole (53) has a longitudinal direction along the radial direction of the turbine wheel (3).

[0101] The first plate portion (71) in which the first hole (77) is formed and the second housing (5) in which the second hole (53) is formed have different amounts of thermal expansion during operation of the turbine (2), and a shear force due to the difference in the amounts of thermal expansion between the first plate portion (71) and the second housing (5) acts on the positioning pin (9). According to the configuration of 7) above, by making the shape of the first hole (77) or the second hole (53) have a longitudinal direction along the radial direction of the turbine wheel (3), the positioning pin (9) does not restrict the thermal expansion between the first plate portion (71) and the second housing (5) compared to when the first hole (77) or the second hole (53) is a round hole, and therefore, it is possible to suppress the generation of an excessive load between the positioning pin (9) and the first hole (77) or between the positioning pin (9) and the second hole (53), and thereby it is possible to effectively suppress the positioning pin (9) from sticking to the first hole (77) or the second hole (53). In addition, according to the configuration of 7) above, the shear force acting on the positioning pin (9) due to the difference in thermal expansion between the first plate portion (71) and the second housing (5) can be reduced, which also effectively prevents the positioning pin (9) from becoming stuck in the first hole (77) or the second hole (53).

[0102] 8) In some embodiments, the turbine (2) according to any one of 1) to 7) above, the at least one positioning pin (9) includes a plurality of positioning pins (9) spaced apart along the circumferential direction of the turbine wheel (3); In a cross section perpendicular to the axis (LA) of the turbine wheel (3), points (CP) that are equally distant from the center positions (LD) of the plurality of positioning pins (9) are positioned shifted toward the tongue side (S1) of the scroll flow path (41) from the axis (LA) of the turbine wheel (3).

[0103] The temperature of the gas flowing through the scroll passage (41) is higher on a tongue-near side (S1), which is closer to the tongue (48) of the scroll passage (41) than the axis (LA) of the turbine wheel (3) of the variable nozzle unit (6), than on a tongue-far side (S2), which is on the opposite side farther from the tongue (48) than the axis (LA) of the turbine wheel (3). Therefore, there is a large difference in the amount of thermal elongation caused by heat input from the gas flowing through the scroll passage (41) between the tongue-near side (S1) and the tongue-far side (S2), which may increase the amount of misalignment of the axis (LB) of the variable nozzle unit (6) with respect to the axis (LA) of the turbine wheel (3).

[0104] According to the configuration of 8) above, by eccentrically positioning the points (CP, center point between the pins, centroid) that are equidistant from the center positions (LD) of the plurality of positioning pins (9) to the tongue-near side (S1) from the axis (LA) of the turbine wheel (3) to the tongue-near side (S1), the positioning pins (9) on the tongue-near side (S1) can suppress the thermal expansion on the tongue-near side (S1) compared to when the center point (CP) between the pins is the same as the axis (LA) of the turbine wheel (3) or is eccentric to the tongue-distant side (S2). This reduces the difference in the amount of thermal expansion between the tongue-near side (S1) and the tongue-distant side (S2), and suppresses an increase in the amount of misalignment of the axis (LB) of the variable nozzle unit (6) with the axis (LA) of the turbine wheel (3). In this case, it is possible to prevent the variable nozzle unit 6 from contacting the first housing 4, the second housing 5, or the turbine wheel 3 due to misalignment of the axis LB of the variable nozzle unit 6 with the axis LA of the turbine wheel 3, and to prevent excessive contact load from acting on positioning due to this contact. By preventing excessive contact load from acting on positioning, it is possible to effectively prevent the positioning pin 9 from sticking to the first hole 77 or the second hole 53.

[0105] 9) In some embodiments, the turbine (2) according to any one of 1) to 8) above, The biasing member (21(21B)) is a first biasing plate portion (211) extending along the radial direction of the turbine wheel (3) and abutting against the second housing (5); and a second biasing plate portion (212) extending along the radial direction and abutting against the first plate-shaped member (7).

[0106] According to the configuration of 9), the biasing member (21 (21B)) including the first biasing plate (211) and the second biasing plate (212) can increase the pressing force (reaction force) against the first plate (71) compared to when a single plate member such as the disc spring (21A) abuts against the second housing (5) and the first plate-shaped member (7). Increasing the pressing force (reaction force) against the first plate (71) by the biasing member (21 (21B)) can more stably maintain the holding structure of the variable nozzle unit (6, first plate-shaped member 7).

[0107] 10) A turbocharger (1) according to at least one embodiment of the present disclosure includes: A turbine (2) according to any one of 1) to 9) above; and a centrifugal compressor (12) configured to be driven by the turbine (2).

[0108] According to the configuration of 10), the holding structure of the variable nozzle unit (6, first plate-like member 7) can be stably maintained, and the risk of wear due to vibration of the variable nozzle unit (6) can be reduced, thereby improving the reliability of the turbocharger (1). [Explanation of symbols]

[0109] 1 turbocharger 2 turbines 3 Turbine Wheel 4. First Housing 5 Second Housing 6 Variable nozzle unit 7 First plate-shaped member 8 Second plate-shaped member 9 Locating Pins 10 Internal combustion engine system 11 Internal combustion engine 12 Centrifugal compressor 13 Impeller 14 Compressor housing 15 Rotating shaft 16 Bearings 21 biasing member 21A Disc spring 22 Stopper part 22A Claw part 31 Hub 32 Turbine blades 41 Scroll flow passage 42 Exhaust gas discharge flow path 43 Interior Space 43A Gas flow path 43B 1st space 44 Locked part 45,51 Opposite surfaces 46 Shroud section 46A,84 Shroud surface 47 Step 48 Tongue 52,75A end face 53 2nd hole 54 Protrusion 61 Variable nozzle vane 62 Annular member 63 Link member 64 Support member 65 Drive mechanism 71 1st plate part 72 First channel wall 73 Back 74 Through Hole 75 Inner edge 76 Outer edge 76A Locking surface 77 Hole 1 78,85 Cylindrical part 81 2nd plate part 82 Second flow path wall 83 2nd back 93A, 93B gap 94 Adhesive layer 95 Sliding layer 95A First hole side sliding layer 95B Second hole side sliding layer BL1 First Reference Line BL2 2nd reference line CP center point G1 First gap G2 Second gap G3 Third gap G4 4th gap LA axis LD center position P1 rear end S1 Tongue side S2 Tongue distal side

Claims

1. a first housing having a scroll flow passage; a turbine wheel provided on the inner circumferential side of the scroll flow passage; a first plate-shaped member including an annular first plate portion; a second plate-shaped member including an annular second plate portion disposed opposite the first plate portion and forming a gas flow path from the scroll flow path toward the turbine wheel between the first plate portion and the second plate portion; at least one variable nozzle vane disposed in the gas flow path; a second housing having an opposing surface that faces a back surface of the first plate portion opposite to a flow path wall surface that faces the gas flow path, with a first space interposed between the second housing and the back surface; an annular member disposed in the first space and configured to rotate relative to the first plate-like member by an external driving force; at least one link member having one end connected to the annular member and the other end connected to the variable nozzle vane, the at least one link member changing a blade angle of the variable nozzle vane connected to the other end in conjunction with rotation of the annular member; a biasing member disposed between the second housing and the first plate-shaped member and configured to bias the first plate portion toward the gas flow path; at least one positioning pin, one end of which is fitted into a first hole formed in the rear surface of the first plate portion and the other end of which is fitted into a second hole formed in the opposing surface of the second housing; at least one stopper portion provided on the opposing surface or the first plate portion, wherein a first gap is formed between the stopper portion and the opposing surface or between the stopper portion and the first plate portion, and the first gap is configured to be smaller than a second gap between the annular member and the opposing surface and a third gap between the at least one link member and the opposing surface; Turbine.

2. The at least one stopper portion is integrally formed with the first plate-shaped member. The turbine of claim 1 .

3. The first plate-shaped member is a cylindrical portion protruding from the rear surface of the first plate portion and inserted through a center hole of the annular member; at least one claw portion protruding from the cylindrical portion toward an outer periphery of the annular member beyond an inner periphery of the annular member and sandwiching the inner periphery of the annular member between the claw portion and the back surface of the first plate portion, The at least one stopper portion includes the at least one claw portion. The turbine of claim 2 .

4. a first housing having a scroll flow passage; a turbine wheel provided on the inner circumferential side of the scroll flow passage; a first plate-shaped member including an annular first plate portion; a second plate-shaped member including an annular second plate portion disposed opposite the first plate portion and forming a gas flow path from the scroll flow path toward the turbine wheel between the first plate portion and the second plate portion; at least one variable nozzle vane disposed in the gas flow path; a second housing having an opposing surface that faces a back surface of the first plate portion opposite to a flow path wall surface that faces the gas flow path, with a first space interposed between the second housing and the back surface; a biasing member disposed between the second housing and the first plate-shaped member and configured to bias the first plate portion toward the gas flow path; at least one positioning pin, one end of which is inserted into a first hole formed in the rear surface of the first plate portion and the other end of which is inserted into a second hole formed in the opposing surface of the second housing, wherein at least one of the one end and the other end of the positioning pin is inserted with a gap; an adhesive layer interposed in the gap, the adhesive layer having adhesive strength reduced by heat input during turbine operation; the at least one locating pin includes a plurality of locating pins spaced apart along a circumferential direction of the turbine wheel; In a cross section perpendicular to the axis of the turbine wheel, points at which distances from the respective center positions of the plurality of positioning pins are equal are disposed shifted toward a tongue portion of the scroll flow passage with respect to the axis of the turbine wheel. Turbine.

5. The adhesive layer is made of a thermoplastic resin material. The turbine of claim 4 .

6. a first housing having a scroll flow passage; a turbine wheel provided on the inner circumferential side of the scroll flow passage; a first plate-shaped member including an annular first plate portion; a second plate-shaped member including an annular second plate portion disposed opposite the first plate portion and forming a gas flow path from the scroll flow path toward the turbine wheel between the first plate portion and the second plate portion; at least one variable nozzle vane disposed in the gas flow path; a second housing having an opposing surface that faces a back surface of the first plate portion opposite to a flow path wall surface that faces the gas flow path, with a first space interposed between the second housing and the back surface; a biasing member disposed between the second housing and the first plate-shaped member and configured to bias the first plate portion toward the gas flow path; at least one positioning pin, one end of which is inserted into a first hole formed in the rear surface of the first plate portion and the other end of which is inserted into a second hole formed in the opposing surface of the second housing; a sliding layer including a solid lubricant covering at least one of an outer circumferential surface of the one end of the at least one positioning pin, an outer circumferential surface of the other end of the at least one positioning pin, an inner circumferential surface of the first hole, or an inner circumferential surface of the second hole, the at least one locating pin includes a plurality of locating pins spaced apart along a circumferential direction of the turbine wheel; In a cross section perpendicular to the axis of the turbine wheel, points at which distances from the respective center positions of the plurality of positioning pins are equal are disposed shifted toward a tongue portion of the scroll flow passage with respect to the axis of the turbine wheel. Turbine.

7. At least one of the first hole and the second hole has a longitudinal direction along a radial direction of the turbine wheel. A turbine according to any preceding claim.

8. the at least one locating pin includes a plurality of locating pins spaced apart along a circumferential direction of the turbine wheel; In a cross section perpendicular to the axis of the turbine wheel, points at which distances from the respective center positions of the plurality of positioning pins are equal are disposed shifted toward a tongue portion of the scroll flow passage with respect to the axis of the turbine wheel. A turbine according to any one of claims 1 to 3.

9. The biasing member is a first biasing plate portion extending along a radial direction of the turbine wheel and abutting against the second housing; a second biasing plate portion extending along the radial direction and abutting against the first plate-shaped member, A turbine according to any preceding claim.

10. A turbine according to any one of claims 1 to 6; a centrifugal compressor configured to be driven by the turbine, Turbocharger.

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