Turbine and supercharger

Abstract

A turbine is provided with: a first turbine scroll flow path (31) which is wound on the outside in the radial direction with respect to a turbine wheel (17) and which communicates with a housing section (29); a second turbine scroll flow path (33) that is wound on the outside in the radial direction with respect to the turbine wheel (17), that communicates with the housing section (29), and that is arranged on the discharge flow path side with respect to the first turbine scroll flow path (31); a partition plate (35) that divides the first turbine scroll flow path (31) and the second turbine scroll flow path (33) in the axial direction; a first tongue section (43) provided at a position facing the downstream end of the first turbine scroll flow path (31); and a second tongue section (51) that is provided at a position facing the downstream end of the second turbine scroll flow path (33), and that has a distance in the radial direction between a partition plate (35)-side end section (51a) and the turbine wheel (17) that differs from a distance in the radial direction between a partition plate (35)-side end section (43a) of the first tongue section (43) and the turbine wheel (17).

Description

Technical Field

[0001] The present invention relates to a turbine and a supercharger. Background Art

[0002] For example, as disclosed in Patent Document 1, as a turbine provided in a supercharger or the like, there is a turbine in which two turbine vortex flow paths are wound radially outwardly relative to the turbine impeller and arranged along the axial direction of the turbine impeller. A tongue portion is provided at a position facing the downstream end of each turbine vortex flow path. Such a turbine is also called a twin-scroll turbine.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Publication No. 2006-348894 Summary of the invention

[0006] Problems to be solved by the invention

[0007] In a turbine having a tongue such as a twin-scroll turbine, the shorter the distance between the tongue and the turbine impeller, the higher the aerodynamic performance. On the other hand, the shorter the distance between the tongue and the turbine impeller, the greater the exciting force acting on the turbine impeller, and the easier it is for the blade vibration to increase. Therefore, in order to improve the aerodynamic performance, it is desirable to reduce the blade vibration of the turbine impeller.

[0008] An object of the present invention is to provide a turbine and a supercharger capable of reducing blade vibration of a turbine impeller.

[0009] Solutions to Solve Problems

[0010] In order to solve the above-mentioned problems, the turbine of the present invention comprises: a storage portion that stores a turbine impeller; a discharge flow path that is continuous with respect to the storage portion in the axial direction of the turbine impeller; a first turbine vortex flow path that is wound on the radially outer side relative to the turbine impeller and is connected to the storage portion; a second turbine vortex flow path that is wound on the radially outer side relative to the turbine impeller and is connected to the storage portion, and is arranged on the discharge flow path side relative to the first turbine vortex flow path; a partition plate that divides the first turbine vortex flow path and the second turbine vortex flow path in the axial direction; a first tongue portion that is arranged at a position facing the downstream end of the first turbine vortex flow path; and a second tongue portion that is arranged at a position facing the downstream end of the second turbine vortex flow path, and the radial distance between the end portion on the partition plate side and the turbine impeller is different from the radial distance between the end portion on the partition plate side of the first tongue portion and the turbine impeller.

[0011] A distance between an end portion of the second tongue portion on the partition plate side and the turbine impeller in the radial direction may be longer than a distance between an end portion of the first tongue portion on the partition plate side and the turbine impeller in the radial direction.

[0012] The average value of the distance between the second tongue portion and the turbine impeller in the radial direction in the axial direction may be greater than the average value of the distance between the first tongue portion and the turbine impeller in the radial direction in the axial direction.

[0013] A radial distance between at least one of the first tongue portion and the second tongue portion and the turbine impeller may increase toward the discharge flow path side in the axial direction.

[0014] The distance between at least one of the first tongue portion and the second tongue portion and the turbine impeller in the radial direction may increase as the distance increases in the rotation direction of the turbine impeller.

[0015] In order to solve the above-mentioned problems, a supercharger according to the present invention includes the above-mentioned turbine.

[0016] Effects of the Invention

[0017] According to the present invention, it is possible to reduce blade vibration of a turbine impeller. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic cross-sectional view showing a supercharger according to an embodiment of the present invention.

[0019] Figure 2 yes Figure 1 AA section view.

[0020] Figure 3 yes Figure 1 BB cross-sectional view.

[0021] Figure 4 yes Figure 2 and Figure 3 CC cross-sectional view.

[0022] Figure 5 It is a cross-sectional view showing the shape of the tongue portion in the first modification.

[0023] Figure 6 It is a cross-sectional view showing the shape of the tongue portion in the second modification. DETAILED DESCRIPTION

[0024] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. The dimensions, materials, and other specific numerical values ​​shown in the embodiments are merely examples for easy understanding, and do not limit the present invention unless otherwise specified. In addition, in this specification and the accompanying drawings, for elements having substantially the same function and structure, the same reference numerals are used to omit their repeated descriptions, and elements that are not directly related to the present invention are omitted from the drawings.

[0025] Figure 1 FIG. 1 is a schematic cross-sectional view showing a supercharger TC according to an embodiment of the present invention. Figure 1 The arrow L direction shown is explained as the left side of the supercharger TC. Figure 1 The arrow R direction shown is explained as the right side of the supercharger TC. Figure 1 As shown, the supercharger TC includes a supercharger body 1. The supercharger body 1 includes a bearing housing 3, a turbine housing 5, and a compressor housing 7.

[0026] The turbine housing 5 is connected to the left side of the bearing housing 3 by a fastening mechanism 9. The fastening mechanism 9 is, for example, a G coupling. The compressor housing 7 is connected to the right side of the bearing housing 3 by a fastening bolt 11. The supercharger TC includes a turbine T and a centrifugal compressor C. The turbine T includes a bearing housing 3 and a turbine housing 5. The turbine T is a twin-scroll turbine. The centrifugal compressor C includes a bearing housing 3 and a compressor housing 7.

[0027] A bearing hole 3a is formed in the bearing housing 3. The bearing hole 3a penetrates in the left-right direction of the supercharger TC. A bearing 13 is provided in the bearing hole 3a. Figure 1 In the figure, a full floating bearing is shown as an example of the bearing 13. However, the bearing 13 may be another bearing such as a semi-floating bearing or a rolling bearing. The bearing 13 supports the shaft 15 so that it can rotate freely. A turbine impeller 17 is provided at the left end of the shaft 15. The turbine impeller 17 is rotatably accommodated in the turbine housing 5. A compressor impeller 19 is provided at the right end of the shaft 15. The compressor impeller 19 is rotatably accommodated in the compressor housing 7.

[0028] Hereinafter, the axial direction, radial direction, and circumferential direction of the supercharger TC are referred to as the axial direction, radial direction, and circumferential direction, respectively. The axial direction of the supercharger TC coincides with the axial direction of the shaft 15, the axial direction of the turbine impeller 17, and the axial direction of the compressor impeller 19. The radial direction of the supercharger TC coincides with the radial direction of the shaft 15, the radial direction of the turbine impeller 17, and the radial direction of the compressor impeller 19. The circumferential direction of the supercharger TC coincides with the circumferential direction of the shaft 15, the circumferential direction of the turbine impeller 17, and the circumferential direction of the compressor impeller 19.

[0029] The compressor housing 7 is provided with an air intake port 21. The air intake port 21 opens on the right side of the supercharger TC. The air intake port 21 is connected to an air cleaner (not shown). A diffuser flow path 23 is formed by the opposing surfaces of the bearing housing 3 and the compressor housing 7. The diffuser flow path 23 pressurizes the air. The diffuser flow path 23 is formed in an annular shape. The diffuser flow path 23 is connected to the air intake port 21 via the compressor impeller 19 on the radial inner side.

[0030] In addition, a compressor scroll flow path 25 is formed in the compressor housing 7. The compressor scroll flow path 25 is formed in an annular shape. The compressor scroll flow path 25 is located, for example, at a radially outer position than the diffuser flow path 23. The compressor scroll flow path 25 is connected to the intake port of the engine (not shown) and the diffuser flow path 23. When the compressor impeller 19 rotates, air is sucked into the compressor housing 7 from the intake port 21. The sucked air is pressurized and accelerated during the process of flowing between the blades of the compressor impeller 19. The pressurized and accelerated air is pressurized in the diffuser flow path 23 and the compressor scroll flow path 25. The pressurized air is guided to the intake port of the engine.

[0031] The turbine housing 5 is provided with a discharge flow path 27, a housing portion 29, a first turbine vortex flow path 31, and a second turbine vortex flow path 33. The discharge flow path 27 opens on the left side of the supercharger TC. The discharge flow path 27 is connected to an exhaust gas purification device (not shown). The discharge flow path 27 is connected to the housing portion 29. The discharge flow path 27 is continuous in the axial direction with respect to the housing portion 29. The housing portion 29 houses the turbine impeller 17. The first turbine vortex flow path 31 and the second turbine vortex flow path 33 are arranged on the radially outer side of the housing portion 29.

[0032] The first turbine scroll flow path 31 and the second turbine scroll flow path 33 are wound radially outward relative to the turbine impeller 17. The first turbine scroll flow path 31 and the second turbine scroll flow path 33 are connected to the storage portion 29. The second turbine scroll flow path 33 is arranged on the discharge flow path 27 side in the axial direction relative to the first turbine scroll flow path 31. A partition plate 35 is formed between the first turbine scroll flow path 31 and the second turbine scroll flow path 33. The partition plate 35 divides the first turbine scroll flow path 31 and the second turbine scroll flow path 33 in the axial direction. The first turbine scroll flow path 31 and the second turbine scroll flow path 33 are connected to the exhaust manifold of the engine (not shown). The exhaust gas discharged from the exhaust manifold of the engine (not shown) is transported to the storage portion 29 via the first turbine scroll flow path 31 and the second turbine scroll flow path 33, and then guided to the discharge flow path 27. The exhaust gas guided to the discharge flow path 27 rotates the turbine impeller 17 during the flow.

[0033] The rotational force of the turbine impeller 17 is transmitted to the compressor impeller 19 via the shaft 15. When the compressor impeller 19 rotates, the air is pressurized as described above. In this way, the air is guided to the intake port of the engine.

[0034] Figure 2 yes Figure 1 AA section view. The AA section is a section perpendicular to the axial direction of the shaft 15 and passing through the first turbine scroll flow path 31. Figure 2 In FIG. 1 , only the outer circumference of the turbine impeller 17 is indicated by a circle.

[0035] like Figure 2As shown, a first exhaust gas inlet port 37 is formed in the turbine housing 5. The first exhaust gas inlet port 37 opens to the outside of the turbine housing 5. Exhaust gas exhausted from an exhaust manifold of an engine (not shown) is introduced into the first exhaust gas inlet port 37.

[0036] A first exhaust gas introduction passage 39 is formed between the first exhaust gas introduction port 37 and the first turbine scroll passage 31. The first exhaust gas introduction passage 39 connects the first exhaust gas introduction port 37 and the first turbine scroll passage 31. The first exhaust gas introduction passage 39 is formed in a straight line, for example. The first exhaust gas introduction passage 39 guides the exhaust gas introduced from the first exhaust gas introduction port 37 to the first turbine scroll passage 31.

[0037] The first turbine vortex flow path 31 is connected to the housing portion 29 via the first communicating portion 41. The first communicating portion 41 is formed in an annular shape over the entire circumference of the housing portion 29. The first turbine vortex flow path 31 guides the exhaust gas introduced from the first exhaust gas introduction path 39 to the housing portion 29 via the first communicating portion 41. The first turbine vortex flow path 31 is wound in a manner approaching the turbine impeller 17 as it advances in the rotation direction RD of the turbine impeller 17. The radial width of the first turbine vortex flow path 31 decreases from the upstream side toward the downstream side.

[0038] A first tongue portion 43 is provided at a position facing the downstream end of the first turbine scroll flow path 31. The first tongue portion 43 separates the downstream side portion of the first turbine scroll flow path 31 from the upstream side portion.

[0039] Figure 3 yes Figure 1 BB cross-sectional view. The BB cross-sectional view is a cross-sectional view perpendicular to the axial direction of the shaft 15 and passing through the second turbine scroll flow path 33. Figure 3 In, with Figure 2 Likewise, with respect to the turbine impeller 17, only the outer circumference is indicated by a circle.

[0040] like Figure 3 As shown, a second exhaust inlet 45 is formed in the turbine housing 5. The second exhaust inlet 45 opens to the outside of the turbine housing 5. The second exhaust inlet 45 is arranged on the exhaust flow path 27 side in the axial direction relative to the first exhaust inlet 37. The first exhaust inlet 37 and the second exhaust inlet 45 are divided in the axial direction by the partition plate 35. Exhaust gas discharged from the exhaust manifold of the engine (not shown) is introduced into the second exhaust inlet 45.

[0041] A second exhaust inlet passage 47 is formed between the second exhaust inlet port 45 and the second turbine scroll flow path 33. The second exhaust inlet passage 47 connects the second exhaust inlet port 45 and the second turbine scroll flow path 33. The second exhaust inlet passage 47 is formed, for example, in a straight line. The second exhaust inlet passage 47 is arranged on the exhaust flow path 27 side in the axial direction relative to the first exhaust inlet passage 39. The first exhaust inlet passage 39 and the second exhaust inlet passage 47 are divided in the axial direction by the partition plate 35. The second exhaust inlet passage 47 guides the exhaust gas introduced from the second exhaust inlet port 45 to the second turbine scroll flow path 33.

[0042] The second turbine vortex flow path 33 is connected to the storage portion 29 via the second communication portion 49. The second communication portion 49 is formed in an annular shape over the entire circumference of the storage portion 29. The second communication portion 49 is arranged on the axial side of the discharge flow path 27 relative to the first communication portion 41. The first communication portion 41 and the second communication portion 49 are divided in the axial direction by the partition plate 35. The second turbine vortex flow path 33 guides the exhaust gas introduced from the second exhaust inlet path 47 to the storage portion 29 via the second communication portion 49. The second turbine vortex flow path 33 is wound in a manner that approaches the turbine impeller 17 as it advances in the rotation direction RD of the turbine impeller 17. The radial width of the second turbine vortex flow path 33 decreases from the upstream side to the downstream side.

[0043] A second tongue portion 51 is provided at a position facing the downstream end of the second turbine vortex flow path 33. The second tongue portion 51 separates the downstream side portion and the upstream side portion of the second turbine vortex flow path 33. The circumferential position of the first tongue portion 43 and the circumferential position of the second tongue portion 51 are consistent with each other. However, the circumferential position of the first tongue portion 43 and the circumferential position of the second tongue portion 51 may also be different from each other.

[0044] Figure 4 yes Figure 2 and Figure 3 The CC cross-section is a cross-section that passes through the first tongue portion 43 and the second tongue portion 51 and includes the rotation axis of the turbine impeller 17 .

[0045] like Figure 4 As shown, the turbine impeller 17 has a plurality of blades 17a. The plurality of blades 17a are arranged at intervals in the circumferential direction. Each blade 17a is formed to extend radially outward from the outer peripheral surface of a hub extending on the rotation axis of the turbine impeller 17. Figure 4 In the example of , the leading edge LE of the blade body 17a extends parallel to the rotation axis of the turbine impeller 17. However, the leading edge LE may be inclined radially outward as it advances toward the axial exhaust flow path 27 side. The leading edge LE is a portion of the outer peripheral edge of the blade body 17a that is opposite to the first turbine vortex flow path 31 and the second turbine vortex flow path 33. Exhaust gas from the first turbine vortex flow path 31 and the second turbine vortex flow path 33 flows into the leading edge LE.

[0046] The first tongue portion 43 and the second tongue portion 51 are arranged radially outward of the leading edge LE of the blade body 17a of the turbine impeller 17. Figure 4 In the example of FIG. 1 , the first tongue portion 43 and the second tongue portion 51, the portions facing the turbine impeller 17, extend in parallel with the rotation axis of the turbine impeller 17. That is, the portions facing the turbine impeller 17 of the first tongue portion 43 and the second tongue portion 51 extend in parallel with the leading edge LE. Hereinafter, when the first tongue portion 43 and the second tongue portion 51 are not particularly distinguished, they are simply referred to as tongue portions.

[0047] The radial distance between the tongue and the turbine impeller 17 is the difference between the distance from the center axis of the turbine impeller 17 to the tongue and the maximum radius of the turbine impeller 17. In other words, the radial distance between the tongue and the turbine impeller 17 is the distance between the tongue and the leading edge LE when the blade body 17a is closest to each tongue. Figure 4 In the example of FIG. 1 , the radial distance between the first tongue portion 43 and the second tongue portion 51 and the turbine impeller 17 is constant regardless of the axial position. However, the radial distance between the first tongue portion 43 and the second tongue portion 51 and the turbine impeller 17 may be different depending on the axial position. Figure 4 2 and 3 show a radial distance D1 between the first tongue portion 43 and the turbine impeller 17 , and a radial distance D2 between the second tongue portion 51 and the turbine impeller 17 .

[0048] like Figure 4 As shown, the radial distance between the end 43a of the first tongue portion 43 on the partition plate 35 side and the turbine impeller 17 is different from the radial distance between the end 51a of the second tongue portion 51 on the partition plate 35 side and the turbine impeller 17. Figure 4 In the example of FIG. 5 , the radial distance between the end 51a of the second tongue portion 51 on the partition plate 35 side and the turbine impeller 17 is longer than the radial distance between the end 43a of the first tongue portion 43 on the partition plate 35 side and the turbine impeller 17. Thus, the radial distance D2 between the second tongue portion 51 and the turbine impeller 17 is longer than the radial distance D1 between the first tongue portion 43 and the turbine impeller 17. That is, the average value of the radial distance between the second tongue portion 51 and the turbine impeller 17 in the axial direction is greater than the average value of the radial distance between the first tongue portion 43 and the turbine impeller 17 in the axial direction.

[0049] The smaller the average value of the radial distance between the tongue portion and the turbine impeller 17 in the axial direction, the higher the aerodynamic performance. On the other hand, the greater the exciting force acting on the turbine impeller 17, the easier it is for the blade vibration to increase. In the present embodiment, as described above, the radial distance between the end 43a of the first tongue portion 43 on the partition plate 35 side and the turbine impeller 17 and the radial distance between the end 51a of the second tongue portion 51 on the partition plate 35 side and the turbine impeller 17 are different from each other. Thus, the radial position of the first tongue portion 43 as a whole and the radial position of the second tongue portion 51 as a whole can be set separately. Therefore, between the first tongue portion 43 and the second tongue portion 51, the average value of the radial distance between the tongue portion and the turbine impeller 17 in the axial direction can be easily made different.

[0050] Therefore, for one of the first tongue portion 43 and the second tongue portion 51, the average value of the radial distance between the tongue portion and the turbine impeller 17 in the axial direction can be reduced, and for the other of the first tongue portion 43 and the second tongue portion 51, the average value of the radial distance between the tongue portion and the turbine impeller 17 in the axial direction can be increased. Therefore, for both the first tongue portion 43 and the second tongue portion 51, the exciting force acting on the turbine impeller 17 can be reduced compared to the case where the average value of the radial distance between the tongue portion and the turbine impeller 17 in the axial direction is uniformly reduced or increased. In addition, according to the reduction of the exciting force, the radial distance between the tongue portion and the turbine impeller 17 can be made close, and the aerodynamic performance can be improved.

[0051] In addition, if the radial distance between the tongue and the turbine impeller 17 becomes shorter, when the blade body 17a of the turbine impeller 17 passes near the tongue, the flow path area formed by the blade body 17a and the tongue becomes narrower instantly, so that the flow of gas becomes a contraction flow. As a result, the circumferential component of the flow velocity of the gas becomes larger near the tongue, and it is easy to generate a peeling vortex at the leading edge LE. The generation of such a peeling vortex acts as a flow obstruction inside the flow path of the turbine impeller 17, and generates a local high pressure field on the discharge flow path 27 side of the blade body 17a. This becomes the source of the exciting force. This becomes the main reason for the increase in blade vibration. In particular, the discharge flow path 27 side in the leading edge LE is more susceptible to the exciting force and is more likely to vibrate than the opposite side of the discharge flow path 27 side in the leading edge LE. Therefore, on the discharge flow path 27 side in the leading edge LE, when the flow of gas is compressed, the blade vibration is particularly likely to increase.

[0052] In the present embodiment, as described above, the radial distance between the end 51a of the second tongue portion 51 on the partition plate 35 side and the turbine impeller 17 is longer than the radial distance between the end 43a of the first tongue portion 43 on the partition plate 35 side and the turbine impeller 17. Thus, the average value of the radial distance between the second tongue portion 51 and the turbine impeller 17 in the axial direction can be made greater than the average value of the radial distance between the first tongue portion 43 and the turbine impeller 17 in the axial direction. Thus, the flow path area formed instantaneously by the blade body 17a and the tongue portion can be enlarged. Therefore, on the discharge flow path 27 side in the leading edge LE, the degree to which the flow of the gas is compressed can be reduced, so that the increase in the blade vibration of the turbine impeller 17 can be appropriately suppressed.

[0053] In the above description, an example is described in which the radial distance between the end 51a of the second tongue portion 51 on the partition plate 35 side and the turbine impeller 17 is longer than the radial distance between the end 43a of the first tongue portion 43 on the partition plate 35 side and the turbine impeller 17. However, the radial distance between the end 51a of the second tongue portion 51 on the partition plate 35 side and the turbine impeller 17 may be shorter than the radial distance between the end 43a of the first tongue portion 43 on the partition plate 35 side and the turbine impeller 17. In addition, the average value of the radial distance between the second tongue portion 51 and the turbine impeller 17 in the axial direction may be smaller than the average value of the radial distance between the first tongue portion 43 and the turbine impeller 17 in the axial direction.

[0054] In addition, in the above description, an example is described in which the radial distance between the end 51a of the second tongue portion 51 and the turbine impeller 17 is longer than the radial distance between the end 43a of the first tongue portion 43 and the turbine impeller 17, and the average value of the radial distance between the second tongue portion 51 and the turbine impeller 17 in the axial direction is larger than the average value of the radial distance between the first tongue portion 43 and the turbine impeller 17 in the axial direction. However, the radial distance between the end 51a of the second tongue portion 51 and the turbine impeller 17 may be shorter than the radial distance between the end 43a of the first tongue portion 43 and the turbine impeller 17, and the average value of the radial distance between the second tongue portion 51 and the turbine impeller 17 in the axial direction may be larger than the average value of the radial distance between the first tongue portion 43 and the turbine impeller 17 in the axial direction. In addition, the radial distance between the end 51a of the second tongue portion 51 and the turbine impeller 17 may be longer than the radial distance between the end 43a of the first tongue portion 43 and the turbine impeller 17, and the average value of the radial distance between the second tongue portion 51 and the turbine impeller 17 in the axial direction may be smaller than the average value of the radial distance between the first tongue portion 43 and the turbine impeller 17 in the axial direction.

[0055] Figure 5 It is a cross-sectional view showing the shape of the tongue portion in the first modification. Figure 5 4 is a cross-sectional view of a section passing through the first tongue portion 43 and the second tongue portion 51 and including the rotation axis of the turbine impeller 17. Figures 1 to 4Compared with the above-described embodiment, the shapes of the first tongue portion 43 and the second tongue portion 51 are different.

[0056] like Figure 5 As shown, in the first modification, in both the first tongue portion 43 and the second tongue portion 51, the radial distance between the tongue portion and the turbine impeller 17 increases as the distance increases toward the discharge flow path 27 in the axial direction. Figure 5 In the example of FIG. 1 , the first tongue portion 43 and the second tongue portion 51 are inclined radially outward as they advance toward the discharge flow path 27 in the axial direction. The portions of the first tongue portion 43 and the second tongue portion 51 facing the turbine impeller 17 are straight when viewed in the circumferential direction. However, the portions of the first tongue portion 43 and the second tongue portion 51 facing the turbine impeller 17 may be curved when viewed in the circumferential direction.

[0057] In the first modification, as described above, the radial distance between the tongue portion and the turbine impeller 17 increases as the first tongue portion 43 and the second tongue portion 51 advance toward the axial discharge flow path 27. As a result, at the leading edge LE, the degree to which the flow of gas is compressed as it advances toward the axial discharge flow path 27 can be reduced. Therefore, the increase in blade vibration of the turbine impeller 17 can be appropriately suppressed.

[0058] In the above, an example is described in which the radial distance between the first tongue portion 43 and the second tongue portion 51 and the turbine impeller 17 increases as the axial direction of the discharge flow path 27 side is advanced. However, the radial distance between the tongue portion and the turbine impeller 17 may increase as the axial direction of the discharge flow path 27 side is advanced in only one of the first tongue portion 43 and the second tongue portion 51. If the radial distance between at least one of the first tongue portion 43 and the second tongue portion 51 and the turbine impeller 17 increases as the axial direction of the discharge flow path 27 side is advanced, the same effect as the above example is achieved.

[0059] The radial distance between at least one of the first tongue portion 43 and the second tongue portion 51 and the turbine impeller 17 may be shortened toward the discharge flow path 27 in the axial direction.

[0060] exist Figure 5 In the example of the embodiment of the present invention, the radial distance between the end 51a of the second tongue portion 51 on the partition plate 35 side and the turbine impeller 17 is longer than the radial distance between the end 43a of the first tongue portion 43 on the partition plate 35 side and the turbine impeller 17. However, in the first modified example, the radial distance between the end 51a of the second tongue portion 51 on the partition plate 35 side and the turbine impeller 17 may be shorter than the radial distance between the end 43a of the first tongue portion 43 on the partition plate 35 side and the turbine impeller 17.

[0061] Figure 6 It is a cross-sectional view showing the shape of the tongue portion in the second modification. Figure 6 1 is a cross-sectional view of a section perpendicular to the axial direction of the shaft 15 and passing through the first turbine scroll flow path 31. Figures 1 to 4 Compared with the above-described embodiment, the shape of the first tongue portion 43 is different.

[0062] like Figure 6 As shown in FIG. 1 , in the second modification, the radial distance between the first tongue portion 43 and the turbine impeller 17 increases as the distance increases in the rotation direction RD of the turbine impeller 17. Figure 6 In the example of FIG. 1 , the radial position of the opposing surface 43b of the first tongue portion 43 that is opposed to the turbine impeller 17 is located radially outward as it advances in the rotation direction RD. The end 43c on the rotation direction RD side of the opposing surface 43b is located radially outward relative to the end 43d on the opposite side of the rotation direction RD side of the opposing surface 43b. The opposing surface 43b is curved when viewed in the axial direction. However, the opposing surface 43b may also be straight when viewed in the axial direction.

[0063] In the second modified example, as described above, the radial distance between the first tongue portion 43 and the turbine impeller 17 increases as the turbine impeller 17 advances in the rotation direction RD. As a result, when the blade body 17a of the turbine impeller 17 passes near the first tongue portion 43, the degree to which the flow of gas is compressed by the blade body 17a and the first tongue portion 43 can be reduced. Therefore, the generation of a separation vortex near the first tongue portion 43 can be suppressed, and the blade vibration of the turbine impeller 17 can be more effectively reduced.

[0064] In the above, an example is described in which the radial distance between the first tongue portion 43 and the turbine impeller 17 becomes longer as the turbine impeller 17 advances in the rotation direction RD. However, in both the first tongue portion 43 and the second tongue portion 51, the radial distance between the tongue portion and the turbine impeller 17 may become longer as the turbine impeller 17 advances in the rotation direction RD. In only one of the first tongue portion 43 and the second tongue portion 51, the radial distance between the tongue portion and the turbine impeller 17 may become longer as the turbine impeller 17 advances in the rotation direction RD. If the radial distance between at least one of the first tongue portion 43 and the second tongue portion 51 and the turbine impeller 17 becomes longer as the turbine impeller 17 advances in the rotation direction RD, the same effect as the above example is achieved.

[0065] The radial distance between at least one of the first tongue portion 43 and the second tongue portion 51 and the turbine impeller 17 may be constant regardless of the circumferential position. The radial distance between at least one of the first tongue portion 43 and the second tongue portion 51 and the turbine impeller 17 may become shorter as the distance advances in the rotation direction RD of the turbine impeller 17.

[0066] The embodiments of the present invention have been described above with reference to the accompanying drawings, but the present invention is not limited to the embodiments. It is obvious that various variations or modifications can be thought of within the scope of the claims, and it is understood that they also belong to the technical scope of the present invention.

[0067] In the above description, an example in which the turbine T is mounted on the supercharger TC is described, but the turbine T may be mounted on a device other than the supercharger TC (for example, a generator, etc.).

[0068] The present invention promotes a balance between improved aerodynamic performance and reduced blade vibration of the turbine impeller, and can therefore, for example, contribute to Goal 7 of the Sustainable Development Goals (SDGs) to "ensure access to affordable, reliable, sustainable and modern energy for all" and Goal 9 to "improve residential infrastructure, promote sustainable industrialization, and seek expansion of innovation."

[0069] Explanation of symbols

[0070] 17—turbine impeller; 27—discharge flow path; 29—storage portion; 31—first turbine vortex flow path; 33—second turbine vortex flow path; 35—partition plate; 43—first tongue portion; 43a—end portion; 51—second tongue portion; 51a—end portion; RD—rotation direction; T—turbine; TC—supercharger.

Claims

1. A turbine, characterized in that: have: a storage portion that stores a turbine impeller; a discharge flow path continuous with the housing portion in the axial direction of the turbine impeller; a first turbine scroll flow path wound radially outwardly relative to the turbine impeller and communicating with the housing portion; a second turbine scroll flow path wound radially outwardly relative to the turbine impeller, communicating with the housing portion, and arranged on the discharge flow path side relative to the first turbine scroll flow path; a partition plate that divides the first turbine scroll flow path and the second turbine scroll flow path in the axial direction; a first tongue portion disposed at a position facing a downstream end of the first turbine scroll flow path; as well as The second tongue portion is arranged at a position facing the downstream end of the second turbine vortex flow path, and the radial distance between the end portion on the partition plate side and the turbine impeller is different from the radial distance between the end portion on the partition plate side of the first tongue portion and the turbine impeller.

2. The turbine according to claim 1, characterized in that A distance between an end portion of the second tongue portion on the partition plate side and the turbine impeller in the radial direction is longer than a distance between an end portion of the first tongue portion on the partition plate side and the turbine impeller in the radial direction.

3. The turbine according to claim 1 or 2, characterized in that An average value of a distance between the second tongue portion and the turbine impeller in the radial direction in the axial direction is greater than an average value of a distance between the first tongue portion and the turbine impeller in the radial direction in the axial direction.

4. The turbine according to any one of claims 1 to 3, characterized in that A distance between at least one of the first tongue portion and the second tongue portion and the turbine impeller in the radial direction increases toward the discharge flow path side in the axial direction.

5. The turbine according to any one of claims 1 to 4, characterized in that A distance between at least one of the first tongue portion and the second tongue portion and the turbine impeller in the radial direction increases as the distance increases in the rotation direction of the turbine impeller.

6. A supercharger, characterized in that: A turbine according to any one of claims 1 to 5.

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