TURBINE AND TURBOCHARGER

Abstract

Turbine (30), comprising: a turbine wheel (3) with a plurality of blades (33); a turbine housing (5) which forms an internal turbine wheel receiving chamber (53) for receiving the turbine wheel (3); and a wastegate valve (55) for controlling a flow rate of exhaust gas flowing through a wastegate passage (110) formed inside the turbine housing (5), wherein the wastegate passage (110) is configured to connect a spiral passage (7a) formed inside the turbine housing (5) and a region (160D) upstream of a trailing edge (37) of each of the plurality of blades (33) in the turbine wheel receiving space (53), wherein a connecting section (120) through which the wastegate passage (110) is connected to the turbine wheel receiving space (53) comprises a plurality of connecting holes (121, 122) which are arranged at intervals in a circumferential direction, and wherein each of the plurality of connecting holes (121, 122) is inclined to a radial direction of the turbine wheel (3), such that the respective connecting hole (121, 122) extends downstream in a direction of rotation of the turbine wheel (3) in the direction of a radial inside of the turbine wheel (3).

Description

TECHNICAL AREA

[0001] The present disclosure relates to a turbine and a turbocharger. BACKGROUND

[0002] A turbocharger is often equipped with a wastegate valve to suppress an excessive increase in boost pressure. The wastegate valve regulates the amount of exhaust gas flowing into a turbine of the turbocharger by opening and closing a wastegate passage, which is a bypass passage to circumvent the turbine (see, for example, patent document 1). Citation list of patent literature

[0003] Patent document 1 (JP 2018 - 127 989 A) discloses a wastegate valve for opening and closing a valve element when a rod of an actuator moves back and forth. The wastegate valve comprises: a valve element; a lever shaft, one end of which is connected to the valve element; a lever plate provided on the other end face of the lever shaft; a lever pin projecting from the lever plate in the thickness direction of the lever plate and rotatably inserted into an opening formed on a joint section of the rod; and an elastic element for exciting the joint section in the axial direction of the lever pin. This prevents the joint section from disengaging from the lever pin.

[0004] Patent document 2 (DE 10 2006 000 340 A1) discloses a turbocharger equipped with a radial turbine housed in a turbine casing and having a blade that is rotated around a turbine axis by exhaust gas from an internal combustion engine flowing from a spiral chamber, which is divided by the turbine casing, to a turbine wheel chamber. In the turbocharger, a gas flow inlet from the spiral chamber to the turbine wheel chamber is located opposite a leading edge section and a shroud section of the blade. Furthermore, a receding section, which recedes increasingly the further a position is located downstream of the turbine axis than the gas flow inlet, is arranged on a downstream side in the direction of turbine axis rotation the further a position is from the turbine axis.

[0005] Patent document 3 (JP 2007-192172A) discloses that, in a turbine wheel, the number of blades arranged within a region X downstream of a second inlet section is less than the number of blades arranged within a region Y upstream of the second inlet section. The exhaust gas flowing in the turbine wheel blows out of an outer circumference of the turbine wheel and splits into a first inlet section and a second inlet section, and then flows out in the axial direction of the turbine wheel.

[0006] Patent document 4 (JP 2008-196332A) discloses that a flow control valve orifice SPA and a wastegate valve orifice WGA are held "fully closed" in a valve control range I. In a valve control range II, the orifice of the wastegate valve WGA is held fully closed, and the flow control valve orifice SPA is adjusted so that the turbine inlet outlet pressure PE becomes equal to or lower than the manifold inlet pressure PI. In a valve control range III, the flow control valve orifice SPA is held fully open, and the orifice of the wastegate valve WGA is adjusted so that the turbine inlet outlet pressure PE becomes equal to or lower than the manifold inlet pressure PI.

[0007] Patent document 5 (DE 10 2014 210 507 A1) discloses an exhaust gas turbocharger for an internal combustion engine, with a turbine wheel rotatably mounted about an axis of rotation in a turbine housing, wherein a first spiral channel through which exhaust gas from the internal combustion engine flows extends radially around the turbine wheel in the turbine housing for supplying exhaust gas to the turbine wheel, wherein the exhaust gas flows out of the turbine housing in an exhaust channel in the direction of flow of the exhaust gas after the turbine, wherein the spiral channel and the exhaust channel can be connected via at least a first wastegate, wherein an exhaust gas quantity can be adjusted through the first wastegate with a tubular slide arranged radially outside the exhaust channel in the turbine housing and axially movable.wherein, for a seal between the outflow channel and the first spiral channel, an axial flange is provided on the spiral channel side of the slide, which seals against an annular sealing surface in the turbine housing by axial displacement of the slide. The design of the exhaust gas turbocharger according to the invention achieves a simple, cost-effective and durable seal. SUMMARY Problems to be solved

[0008] The wastegate passage described in patent document 1 is configured to direct exhaust gas to the downstream side of the turbine to bypass the turbine wheel blades. Therefore, if exhaust gas flows through the wastegate passage to cause the exhaust gas exceeding the turbine intake flow rate to bypass the blades, the exhaust gas flowing through the wastegate passage cannot contribute to improving the turbine's performance.

[0009] In light of the foregoing, an object of at least one embodiment of the present disclosure is to improve the performance of the turbine when exhaust gas is bypassed to the wastegate passage. Problem solving (1) A turbine according to at least one embodiment of the present disclosure is provided with: a turbine wheel having a plurality of blades; a turbine housing which forms a turbine wheel receiving chamber inside for receiving the turbine wheel; and a wastegate valve for controlling a flow rate of exhaust gas flowing through a wastegate passage formed inside the turbine housing. The wastegate passage is configured to connect a spiral passage formed inside the turbine housing and a region upstream of a trailing edge of each of the plurality of blades in the turbine wheel receiving chamber. A connecting section through which the wastegate passage communicates with the turbine wheel receiving chamber comprises a plurality of connecting holes arranged at intervals in a circumferential direction.Each of the plurality of connecting holes is oblique to a radial direction of the turbine wheel, so that the hole extends downstream in a direction of rotation of the turbine wheel towards a radial inside of the turbine wheel. (2) A turbine according to at least one alternative embodiment of the present disclosure is provided with: a turbine wheel having a plurality of blades; a turbine housing which forms an internal turbine wheel receiving chamber for receiving the turbine wheel; and a wastegate valve for controlling a flow rate of exhaust gas flowing through a wastegate passage formed inside the turbine housing. The wastegate passage is configured to connect a spiral passage formed inside the turbine housing and a region upstream of a trailing edge of each of the plurality of blades in the turbine wheel receiving chamber. The turbine further comprises a bypass section configured to connect the wastegate passage and an exhaust gas passage formed downstream of the turbine wheel. The wastegate passage includes an opening which is opened and closed by the wastegate valve.The wastegate valve is configured to set a distribution ratio of the exhaust gas flow rate by adjusting the degree of opening of the wastegate valve, namely the distribution ratio of the exhaust gas flow rate between the flow directed towards the area upstream of the trailing edges of the majority of blades in the turbine wheel intake chamber and the flow directed via a bypass section to the exhaust gas passage, by adjusting the degree of opening of the wastegate valve. (3) A turbocharger according to at least one embodiment of the present disclosure is provided with the turbine according to the configuration (1) or (2) above. Beneficial effects

[0010] According to at least one embodiment of the present disclosure, it is possible to improve the performance of the turbine if exhaust gas is bypassed at the wastegate passage. BRIEF DESCRIPTION OF THE DRAWINGS Fig. Figure 1 is a cross-sectional view showing an example of a turbocharger according to some embodiments. Fig. Figure 2 is a perspective view showing the appearance of a turbine wheel according to some embodiments. Fig. Figure 3 is a view that schematically shows a cross-section of part of a turbine according to some embodiments. Fig. Figure 4 is a view that schematically shows a cross-section of part of a turbine according to another embodiment. Fig. 5A is an example of a view that schematically represents the VV view in Fig. 3 shows. Fig. 5B is another example of a view that schematically represents the VV view in Fig. 3 shows. Fig. 5C is another example of a view that schematically represents the VV view in Fig. 3 shows. Fig. 5D is another example of a view that schematically represents the VV view in Fig. 3 shows. Fig. 5E is another example of a view that schematically represents the VV view in Fig. 3 shows. Fig. 5F is another example of a view that schematically represents the VV view in Fig. 3 shows. Fig. Figure 6 is a view that schematically shows a cross-section of a turbine according to another embodiment. Fig. Figure 7 is a view that schematically shows a cross-section of part of a turbine according to yet another embodiment. Fig. Figure 8A is a view that schematically shows a cross-section of part of a turbine according to yet another embodiment. Fig. Figure 8B is a view that schematically shows a cross-section of part of a turbine according to yet another embodiment. Fig. Figure 8C is a view that schematically shows a cross-section of part of a turbine according to yet another embodiment. Fig. Figure 9A is a view that schematically shows a cross-section of part of a turbine according to yet another embodiment. Fig. Figure 9B is a view that schematically shows a cross-section of part of a turbine according to yet another embodiment. Fig. Figure 9C is a view that schematically shows a cross-section of part of a turbine according to yet another embodiment. DETAILED DESCRIPTION

[0011] Embodiments of the present disclosure are described below with reference to the accompanying drawings. However, unless specifically identified, dimensions, materials, shapes, relative positions, and the like of components described in the embodiments are intended to be interpreted as illustrative only and are not intended to limit the scope of the present disclosure.

[0012] For example, an expression of a relative or absolute arrangement, such as "in a direction", "along a direction", "parallel", "orthogonal", "centered", "concentric" and "coaxial", should not be interpreted as specifying only the arrangement in a strictly literal sense, but should also include a state in which the arrangement is relatively offset by a tolerance or by an angle or a distance, making it possible to achieve the same function.

[0013] For example, an expression of an equal state, such as "equal", "identical" and "uniform", should not be interpreted as indicating only the state in which the feature is strictly equal, but also as including a state in which there is a tolerance or a difference that can still achieve the same function.

[0014] Furthermore, for example, an expression of a shape, such as a rectangular shape or a cylindrical shape, should not only be interpreted as the geometrically strict shape, but also includes a shape with irregularities or chamfered corners within the area in which the same effect can be achieved.

[0015] On the other hand, an expression such as "comprise", "include", "exhibit", "contain" and "form" should not exclude other components. (Overall configuration of turbocharger 1)

[0016] Fig. Figure 1 is a cross-sectional view showing an example of a turbocharger 1 according to some embodiments.

[0017] The turbocharger 1 according to some embodiments is an exhaust gas turbocharger for charging air to an engine that is mounted on a vehicle, such as an automobile.

[0018] The turbocharger 1 comprises a turbine wheel 3 and a compressor wheel 4, which are coupled to each other by a rotor shaft 2 as a rotating shaft, a housing (turbine housing) 5 for rotatably mounting the turbine wheel 3, and a housing (compressor housing) 6 for rotatably mounting the compressor wheel 4. The turbine housing 5 comprises a spiral section 7 which has a spiral passage 7a inside. The compressor housing 6 comprises a spiral section 8 which has a spiral passage 8a inside.

[0019] A turbine 30 according to some embodiments is provided with the turbine wheel 3 and the housing 5. A compressor 40 according to some embodiments is provided with the compressor wheel 4 and the housing 6. (Turbine wheel 3)

[0020] Fig. Figure 2 is a perspective view showing the appearance of the turbine wheel 3 according to some embodiments.

[0021] Fig. Figure 3 is a view that schematically shows a cross-section of part of the turbine 30 according to some embodiments.

[0022] The turbine wheel 3 according to some embodiments is an impeller coupled to the rotor shaft 2 and rotated about an axis of rotation AXW. The turbine wheel 3 according to some embodiments comprises a hub 31 with a hub surface 32 inclined to the axis of rotation AXW, and a plurality of blades (rotor blades) 33 arranged on the hub surface 32 in a cross-section along the axis of rotation AXW. The [unclear text] in the Fig. 1 and Fig. Turbine wheel 3 shown in Figure 2 is a radial turbine, but it can also be a mixed-flow turbine. Fig. In Figure 2, the arrow R indicates a direction of rotation of the turbine wheel 3. The blades 33 are arranged at intervals in the circumferential direction of the turbine wheel 3.

[0023] The turbine wheel 3 according to some embodiments has a neck section 35 where the area of ​​the flow passage formed between two circumferentially adjacent blades 33 is smallest (see Fig. 3) In the turbine wheel 3 according to some embodiments, the neck section 35 is formed on the pressure side of each blade 33 in a region closer to the leading edge 36 than to the trailing edge 37 of the blade.

[0024] Although the perspective view illustration has been omitted, the compressor wheel 4, according to some embodiments, also has the same configuration as the turbine wheel 3, according to some embodiments. That is, the compressor wheel 4, according to some embodiments, is an impeller coupled to the rotor shaft 2 and rotated about the axis of rotation AXW. The compressor wheel 4, according to some embodiments, comprises a hub 41 with a hub surface 42 inclined to the axis of rotation AXW, and a plurality of blades (rotor blades) 43 arranged on the hub surface 42 in a cross-section along the axis of rotation AXW. The blades 43 are arranged at intervals in the circumferential direction of the compressor wheel 4.

[0025] In the following description, the extension direction of the axis of rotation AXW is simply referred to as the axial direction, the radial direction with respect to the axis of rotation AXW is simply referred to as the radial direction, and the circumferential direction with respect to the axis of rotation AXW is simply referred to as the circumferential direction.

[0026] In the turbocharger 1 configured in this way, exhaust gas, which serves as the working fluid of the turbine 30, flows from the leading edge 36 to the trailing edge 37 of the turbine wheel 3. This rotates the turbine wheel 3 and in turn rotates the compressor wheel 4 of the compressor 40, which is coupled to the turbine wheel 3 via the rotor shaft 2. As a result, intake air from an inlet section 40a of the compressor 40 is compressed by the compressor wheel 4 as it flows from the leading edge 46 to the trailing edge 47 of the compressor wheel 4. (Overview of wastegate passage 110)

[0027] As described above, the turbine 30, according to some embodiments, comprises the turbine wheel 3 and the turbine housing 5, which internally forms a turbine wheel receiving chamber 53 for receiving the turbine wheel 3. The turbine 30, according to some embodiments, includes a wastegate valve 55 for controlling the flow rate of exhaust gas flowing through a wastegate passage 110 formed inside the turbine housing 5. In some embodiments, for example as in Fig. 3 and the one described later Fig. 4, Fig. 6, Fig. 7 and Fig. 8A to Fig. As shown in Figure 8C, the wastegate valve 55 can comprise a pivoting valve whose radially outer position is pivotably supported by the turbine housing 5. Furthermore, for example as described later Fig. 9A to Fig. As shown in Figure 9C, the wastegate valve 55A is configured to be movable in the axial direction without changing its position relative to the turbine housing 5, rather than being pivotable.

[0028] Fig. Figure 1 shows a state in which the wastegate valve 55 closes an opening 111 of the wastegate passage 110, which is opened and closed by the wastegate valve 55. Furthermore, it shows Fig. 3 a state in which the opening 111 is open.

[0029] Although, for example, the Fig. 1, Fig. Figure 3 and the figures described later show the position of the pivot center Cv of the wastegate valve 55, but the position of the pivot center Cv is not limited to the positions shown in the figures.

[0030] In the turbine 30 according to some embodiments, as in the Fig. 1, Fig. As shown in Figure 3 and the figures described later, the wastegate passage 110 is configured to connect the spiral passage 7a formed inside the turbine housing 5 and a region upstream of the trailing edge 37 of each of the plurality of blades 33 in the turbine wheel receiving chamber 53. In particular, according to some embodiments, the wastegate passage 110 comprises a connecting section 120 having an opening section 57 at its downstream end, formed on an inner surface 51 of the housing 5 facing the tip sections of the blades 33. In some embodiments, the wastegate passage 110 communicates with the turbine wheel receiving chamber 53 through the connecting section 120. Details of the connecting section 120 are described later.

[0031] In a typical turbocharger, the turbine's wastegate is configured to direct exhaust gas to the downstream side of the turbine, bypassing the turbine wheel blades. Therefore, if exhaust gas is flowing through the wastegate to cause the exhaust gas exceeding the turbine's intake flow to bypass the blades, this exhaust gas flowing through the wastegate will not contribute to improving the turbine's performance.

[0032] In contrast, in some embodiments of the turbine 30, the wastegate passage 110 is configured such that exhaust gas flowing through the wastegate passage 110 is directed to an area upstream of the trailing edge 37 of each of the blades 33 in the turbine wheel receiving chamber 53. This allows the exhaust gas in the wastegate passage 110 to flow to the majority of the blades 33 of the turbine wheel 3, so that energy from the exhaust gas can be recovered as kinetic energy of the turbine wheel 3. Consequently, power can be recovered from the exhaust gas flowing through the wastegate passage 110, and the performance of the turbine 30 can be improved by bypassing the wastegate passage 110.

[0033] In a typical turbocharger turbine, there is a gap between the tip 34 of the blade 33 and the inner surface 51 of the casing 5. Leakage flow (tip leakage) occurs through this gap, which affects the flow field and the performance of the turbomachine.

[0034] In a turbocharger turbine, the upstream end of the wastegate passage is generally provided at a flow passage radially outside the turbine wheel 3, such as in the middle of the spiral passage 7a or upstream of the spiral passage 7a. Therefore, in the turbine 30, according to some embodiments, in order to connect the wastegate passage 110 with the turbine wheel receiving space 53, the downstream end of the wastegate passage 110, i.e., the downstream end of the connecting section 120 according to some embodiments, is provided at the inner surface 51 of the housing 5, which faces the tips 34 of the blades 33. Therefore, according to some embodiments, with the turbine 30, since the exhaust gas that has passed through the wastegate passage 110 flows from the inner surface 51 of the housing 5 to the tip 34 when it is directed into the turbine wheel receiving chamber 53, the flow of the tip leakage is blocked and the tip leakage is suppressed.This can improve the efficiency of turbine 30, and thus the performance of turbine 30 can be improved.

[0035] With the turbocharger 1 according to some embodiments, since the turbocharger 1 according to some embodiments is provided with the turbine 30 according to some embodiments, it is possible to improve the part-load performance of the turbine 30.

[0036] In the turbine 30 according to some embodiments, such as in Fig. As shown in Figure 3, the wastegate passage 110 can be configured to connect the spiral passage 7a and an area downstream of the neck section 35 and upstream of the trailing edge 37 of each of the plurality of blades 33 in the turbine wheel receiving space 53.

[0037] In general, the turbine intake flow rate is determined by the flow area of ​​the throat section. Therefore, if the wastegate passage 110 is connected to an area upstream of the throat section 35, the intake flow rate of the turbine 30 can be reduced due to exhaust gas flowing through the wastegate passage 110 into the area upstream of the throat section 35.

[0038] Therefore, by connecting the wastegate passage 110 to a region downstream of the throat section 35, as in some embodiments of the turbine 30, the influence on the intake flow rate of the turbine 30 can be suppressed, even if the exhaust gas flowing through the wastegate passage 110 enters the turbine wheel receiving chamber 53. Furthermore, by connecting the wastegate passage 110 to a region downstream of the throat section 35, compared to connecting the wastegate passage 110 to a region upstream of the throat section 35, the exhaust gas can be discharged more efficiently via the wastegate passage 110 to the downstream side of the turbine 30. (Case in which the turbine wheel has 3 divider blades 133)

[0039] Fig. Figure 4 is a view that schematically shows a cross-section of part of the turbine 30 according to another embodiment.

[0040] In the turbine 30 according to some embodiments, for example as in Fig. As shown in Figure 4, the turbine wheel 3 can further comprise a plurality of divider blades 133, which are arranged between the plurality of blades 33 and are configured such that the trailing edge 137 of each of the plurality of divider blades 133 is located on the leading edge side 36 compared to the trailing edge 37 of each of the plurality of blades 33. Additionally, in some embodiments of the turbine 30, the wastegate passage 110 can be configured to connect the spiral passage 7a and a region downstream of the trailing edge 137 of each of the divider blades 133 and upstream of the trailing edge 37 of each of the plurality of blades 33 in the turbine wheel receiving space 53.

[0041] If the throat section 35 exists within the area of ​​existence of the divider blade 133 in the flow passage formed between two circumferentially adjacent blades 33, the wastegate passage 110 is connected to a region upstream of the trailing edges 37 of the blades 33 and downstream of the trailing edges 137 of the divider blades 133 in the turbine wheel receiving chamber 53 by connecting the wastegate passage 110 to a region downstream of the throat section 35. As a result, even if the exhaust gas that has flowed through the wastegate passage 110 enters the turbine wheel receiving chamber 53, its influence on the intake flow rate of the turbine 30 can be suppressed.Furthermore, by connecting the wastegate passage 110 to a region downstream of the trailing edge 137 of the divider blade 133, compared to connecting the wastegate passage 110 to a region upstream of the trailing edge 137 of the divider blade 133, the exhaust gas can be efficiently discharged via the wastegate passage 110 to the downstream side of the turbine 30. Moreover, since the turbine wheel 3 has the majority of divider blades 133, the performance of the turbine 30 can be improved even if exhaust gas does not flow through the wastegate passage 110. (Connecting section 120 according to some embodiments)

[0042] Fig. 5A is an example of a view that schematically represents the VV view in Fig. 3 shows.

[0043] Fig. 5B is another example of a view that schematically represents the VV view in Fig. 3 shows.

[0044] Fig. 5C is another example of a view that schematically represents the VV view in Fig. 3 shows.

[0045] Fig. 5D is another example of a view that schematically represents the VV view in Fig. 3 shows.

[0046] Fig. 5E is another example of a view that schematically represents the VV view in Fig. 3 shows.

[0047] Fig. 5F is another example of a view that schematically represents the VV view in Fig. 3 shows.

[0048] In the Fig. 5A to Fig. Turbine wheel 3 is not shown in 5F.

[0049] In some embodiments, such as in the Fig. 5A and Fig. As shown in Figure 5B, the connecting section 120 can comprise a plurality of connecting holes 121, 122 arranged at intervals in the circumferential direction.

[0050] This allows the exhaust gas in the wastegate passage 110 to flow through the plurality of connecting holes 121, 122 to the plurality of blades 33 of the turbine wheel 3, thereby ensuring the velocity of exhaust gas that is blown out of the plurality of connecting holes 121, 122.

[0051] Each of the in the Fig. 5A and Fig. The plurality of connecting holes 121, 122 shown in 5B can be oblique to the radial direction, so that the hole extends downstream in the direction of rotation R of the turbine wheel 3 to the radially inner side.

[0052] For example, each of the in Fig. The plurality of connecting holes 121 shown in Figure 5A provides a constant through-cross-sectional area from an upstream end section 121a to a downstream end section 121b.

[0053] For example, each of the in Fig. The plurality of connecting holes 122 shown in 5B provides a through cross-sectional area that gradually increases from an upstream end section 122a to a downstream end section 122b.

[0054] In the Fig. 5A and Fig. In the plurality of connecting holes 121, 122 shown in Figure 5B, the cross-sectional shape of the passage, viewed from the upstream end section 121a, 122a to the downstream end section 121b, 122b, can be rectangular, circular, or polygonal other than rectangular. Alternatively, the cross-sectional shape of the passage can be elliptical, with the principal axis extending along the circumferential direction.

[0055] The scope of the order division of the in the Fig. 5A and Fig. The plurality of connecting holes 121, 122 shown in 5B can be regular or irregular. The circumferential arrangement division and the number of holes in the Fig. 5A and Fig. The plurality of connecting holes 121, 122 shown in 5B can be adjusted so that vibration of the blades 33 is not induced by exhaust gas blown out of the connecting holes 121, 122.

[0056] In some embodiments, such as in the Fig. 5C to Fig. As shown in Figure 5E, the connecting section 120 can include a groove 125 extending along the circumferential direction.

[0057] This allows the exhaust gas to flow through the groove 125 in the wastegate passage 110, which extends circumferentially to the majority of the blades 33 of the turbine wheel 3, suppressing vibration of the blades 33 and improving the reliability of the turbine 30.

[0058] The groove 125 according to some embodiments can be subdivided into several grooves along the circumferential direction, for example as in Fig. 5C shown, or it can be a single groove 125 that is provided continuously around the entire circumference.

[0059] In some embodiments, such as in the Fig. 5D and Fig. As shown in Figure 5E, the turbine can be provided with a plurality of nozzle elements 131, 132 which are arranged in the groove 125 at intervals in the circumferential direction and are configured to guide exhaust gas passing through the groove 125 to flow downstream in the direction of rotation R of the turbine wheel 3 as the exhaust gas moves inwards in the radial direction.

[0060] This allows the majority of nozzle elements 131, 132 to guide the exhaust gas as described above, enabling the exhaust gas to flow efficiently into the turbine wheel intake chamber 53. Consequently, it is possible to further improve the performance of the turbine 30 by bypassing exhaust gas to the wastegate passage 110.

[0061] For example, each of the majority of nozzle elements 131, which are in Fig. The 5D model shows a plate-shaped element whose thickness direction is the axial direction (the depth direction on the paper in Fig. 5D). This allows the manufacturing costs of the nozzle elements 131 to be reduced.

[0062] Alternatively, for example, each of the majority of nozzle elements 132, which are in Fig. 5E shows a wing-shaped element. This allows the exhaust gas to flow efficiently into the turbine wheel receiving chamber 53.

[0063] In some embodiments, such as in Fig. As shown in Figure 5F, the connecting section 120 can have a convergent-divergent shape. That is, in some embodiments, as in Fig. As shown in Figure 5F, the connecting section 120 can have a nozzle section 140 with a convergent-divergent shape.

[0064] Generally, when the wastegate valve 55, 55A is open to allow exhaust gas to flow through the wastegate passage 110, the pressure ratio of the turbine 30 tends to be high. Therefore, the flow velocity of exhaust gas passing through the connecting section 120 is very high. Consequently, as described above, if the connecting section 120 has a convergent-divergent shape or a De Laval nozzle shape, energy from exhaust gas expelled from the connecting section 120 can be efficiently converted into kinetic energy of the turbine wheel 3. As a result, it is possible to further improve the performance of the turbine 30 by bypassing exhaust gas to the wastegate passage 110. Furthermore, since it is relatively easy to machine the connecting section 120 into a convergent-divergent shape, manufacturing costs can be reduced.

[0065] As in the Fig. 5C to Fig. As shown in Figure 5E, when the connecting section 120 includes the groove 125 which extends in the circumferential direction, the width of the groove 125 can be changed along the axial direction with the radial position, so that the groove 125 has a convergent-divergent shape when viewed along the circumferential direction.

[0066] Fig. Figure 6 is a view that schematically shows a cross-section of the turbine 30 according to another embodiment.

[0067] In some embodiments, such as in Fig. As shown in Figure 6, the wastegate passage 110 can include a spiral section 150 configured to have a cross-sectional area that decreases downstream in the direction of rotation R of the turbine wheel 3 and is connected to the turbine wheel receiving space 53 through the groove 125.

[0068] This allows the spiral section 150 of the wastegate passage 110 to guide the exhaust gas along the circumferential direction, thereby suppressing the difference in the flow rate of exhaust gas flowing into the turbine wheel receiving chamber 53 through the groove 125, depending on the circumferential position. As a result, it is possible to further improve the performance of the turbine 30 by bypassing exhaust gas to the wastegate passage 110. (Case with bypass section 160)

[0069] Fig. Figure 7 is a view that schematically shows a cross-section of part of the turbine 30 according to yet another embodiment. Fig. Figure 7 shows a state in which opening 111 is open.

[0070] The Fig. 8A to Fig. Figures 8C each represent a view that schematically shows a cross-section of a part of the turbine 30 according to yet another embodiment.

[0071] Fig. Figure 8A shows a state in which the wastegate valve 55 closes the opening 111.

[0072] Fig. Figure 8B shows a case in which the opening degree of the wastegate valve 55 is relatively small.

[0073] Fig. Figure 8C shows a case in which the opening degree of the wastegate valve 55 is relatively large.

[0074] The Fig. 9A to Fig. Figures 9C each show a schematic cross-section of a part of the turbine 30 according to yet another embodiment.

[0075] Fig. 9A shows a state in which the wastegate valve 55A closes the opening 111.

[0076] Fig. Figure 9B shows a case in which the opening degree of the wastegate valve 55A is relatively small.

[0077] Fig. Figure 9C shows a case in which the opening degree of the wastegate valve 55A is relatively large.

[0078] As in the Fig. 7, Fig. 8A to Fig. 8C and Fig. 9A to Fig. As shown in Figure 9C, the turbine 30 may, according to some embodiments, further comprise a bypass section 160 configured to connect the wastegate passage 110 and an exhaust gas passage 171 formed downstream of the turbine wheel 3.

[0079] This makes it possible to increase the flow rate of exhaust gas passing through wastegate passage 110. Furthermore, even if the amount of supplied exhaust gas exceeds the amount required to drive compressor 40, the excess exhaust gas from turbine 30 can be bypassed. Consequently, bypassing exhaust gas to wastegate passage 110 improves the performance of turbine 30 and suppresses excessive turbine 30 rotation, thus improving turbine 30 reliability.

[0080] In particular, in the Fig. In the turbine 30 shown in Figure 7, an upstream end 161 of the bypass section 160 is connected to a region of the wastegate passage 110 downstream of the opening 111. A downstream end 163 of the bypass section 160 is connected to the exhaust passage 171, which is formed downstream of the trailing edges 37 of the blades 33 of the turbine wheel 3. In the Fig. In the turbine 30 shown in Figure 7, when the wastegate valve 55 opens the opening 111, the exhaust gas flows from the opening 111 into the connecting section 120 and the bypass section 160.

[0081] In the Fig. In the turbine 30 shown, the exhaust gas, which flows into the connecting section 120 as described above, flows from the connecting section 120 into the turbine wheel receiving chamber 53 and flows to the majority of blades 33 of the turbine wheel 3.

[0082] In the Fig. In the turbine 30 shown, the exhaust gas flowing into the bypass section 160 does not flow from the bypass section 160 into the turbine wheel receiving chamber 53, but flows directly into the exhaust gas passage 171.

[0083] As in the Fig. 7, Fig. 8A to Fig. 8C and Fig. 9A to Fig. As shown in Figure 9C, in some embodiments of the turbine 30, the connecting section 120, through which the wastegate passage 110 is connected to the turbine wheel receiving chamber 53, can be arranged upstream of the opening 111 in the axial direction. The bypass section 160 can be arranged downstream of the opening 111 in the axial direction.

[0084] For example, if the opening degree of the wastegate valve 55, 55A is relatively small and the axial position of the gap between the wastegate valve 55, 55A and the opening 111 is located upstream of the upstream end 161 of the bypass section 160 along the axial direction, the flow of exhaust gas from the opening 111 to the bypass section 160 is blocked by the wastegate valve 55, 55A. Therefore, the exhaust gas flows from the opening 111 to the connecting section 120. In other words, if the opening degree of the wastegate valve 55, 55A is relatively small, the exhaust gas flows from the opening 111 mainly to the connecting section 120.

[0085] If the opening degree of the wastegate valve 55, 55A is relatively large, it is less likely that the exhaust gas flow from opening 111 to bypass section 160 will be blocked by the wastegate valve 55, 55A, allowing the exhaust gas to flow easily to bypass section 160. In other words, if the opening degree of the wastegate valve 55, 55A is relatively large, as is the case, for example, in the Fig. 7, Fig. 8A to Fig. 8C and Fig. 9A to Fig. As shown in Figure 9C, the upstream end 161 of the bypass section 160 is located within the area of ​​the axial position of the gap between the wastegate valve 55, 55A and the opening 111, so that the exhaust gas flows from the opening 111 not only to the connecting section 120, but also to the bypass section 160.

[0086] Thus, the distribution ratio of the exhaust gas flowing to the connecting section 120 and the bypass section 160 can be adjusted by the opening degree of the wastegate valve 55, 55A. Consequently, it is possible to further improve the performance of the turbine 30 by bypassing exhaust gas to the wastegate passage 110, and it is possible to suppress excessive rotation of the turbine 30 to improve its reliability.

[0087] As in the Fig. 8A to Fig. As shown in Figure 8C, the pivotally supported wastegate valve 55 can have a distal end section 56 that is located furthest from the pivot center Cv of the wastegate valve 55. For example, the Fig. 8A to Fig. Turbine 30 shown in Figure 8C has an adjacent section 115 which faces the distal end section 56 of the wastegate valve 55 in the wastegate passage 110 with a relatively small gap between them. For example, in the Fig. 8A to Fig. In the turbine 30 shown in Figure 8C, the upstream end 161 of the bypass section 160 is arranged downstream of the facing section 115 in the axial direction.

[0088] In the Fig. 8A to Fig. The turbine 30 shown in Figure 8C flows when the wastegate valve 55 closes the opening 111, as shown in Figure 8C. Fig. 8A shows no exhaust gas to the wastegate passage 110 downstream of the opening 111.

[0089] In the Fig. 8A to Fig. In the turbine 30 shown in Figure 8C, the case is considered in which the opening degree of the wastegate valve 55 is relatively small, as in Fig. Figure 8B shows that at least a portion of the distal end section 56 of the wastegate valve 55 and the facing section 115 overlap along the axial direction, that is, at least a portion of the distal end section 56 is located upstream of the upstream end 161 of the bypass section 160 in the axial direction. Since, in this case, at least a portion of the distal end section 56 of the wastegate valve 55 overlaps the facing section 115 along the axial direction, exhaust gas can hardly flow through the gap between the distal end section 56 of the wastegate valve 55 and the facing section 115. Therefore, the exhaust gas flows from the opening 111 into the connecting section 120, except for a small amount that flows through the gap.

[0090] In the Fig. 8A to Fig. In the turbine 30 shown in Figure 8C, the case is considered in which the opening degree of the wastegate valve 55 is relatively large, as in Fig. Figure 8C shows that the distal end section 56 of the wastegate valve 55 is arranged downstream of the facing section 115 along the axial direction, meaning that at least part of the upstream end 161 of the bypass section 160 is arranged upstream of the distal end section 56 of the wastegate valve 55 in the axial direction. In this case, the exhaust gas flows from the opening 111 into the connecting section 120 and the bypass section 160.

[0091] Furthermore, for example, as in the Fig. 9A to Fig. As shown in Figure 9C, the wastegate valve 55A can be configured to be movable in the axial direction without changing its position relative to the turbine housing 5, instead of being pivotable, and can be configured to close or open the orifice 111 by moving in the axial direction. The Fig. 9A to Fig. The wastegate valve 55A shown in Figure 9C can have a distal end section 56A located on the radially inner side of the wastegate valve 55A. For example, the one shown in the Fig. 9A to Fig. Turbine 30 shown in Figure 9C has an adjacent section 115A which faces the distal end section 56A of the wastegate valve 55A in the wastegate passage 110 with a relatively small gap between them. For example, in the Fig. 9A to Fig. Turbine 30 shown in Figure 9C is arranged at the upstream end 161 of the bypass section 160 downstream of the facing section 115A in the axial direction.

[0092] In the Fig. 9A to Fig. Turbine 30 shown in Figure 9C flows when the wastegate valve 55A closes the opening 111, as shown in Figure 9C. Fig. 9A shows no exhaust gas to the wastegate passage 110 downstream of the opening 111.

[0093] In the Fig. 9A to Fig. In the turbine 30 shown in Figure 9C, the case is considered in which the opening degree of the wastegate valve 55A is relatively small, as in Fig. Figure 9B shows that at least part of the distal end section 56A of the wastegate valve 55A and the facing section 115A overlap along the axial direction, that is, at least part of the distal end section 56A is located upstream of the upstream end 161 of the bypass section 160 in the axial direction. Since, in this case, at least part of the distal end section 56A of the wastegate valve 55A overlaps the facing section 115A along the axial direction, exhaust gas can hardly flow through the gap between the distal end section 56A of the wastegate valve 55A and the facing section 115A. Therefore, the exhaust gas flows from the opening 111 into the connecting section 120, except for a small amount that flows through the gap.

[0094] In the Fig. 9A to Fig. In the turbine 30 shown in Figure 9C, the case is considered in which the opening degree of the wastegate valve 55A is relatively large, as in Fig. Figure 9C shows that the distal end section 56A of the wastegate valve 55A is arranged downstream of the facing section 115A along the axial direction, meaning that at least part of the upstream end 161 of the bypass section 160 is arranged upstream of the distal end section 56A of the wastegate valve 55A in the axial direction. In this case, the exhaust gas flows from the opening 111 into the connecting section 120 and the bypass section 160.

[0095] As in the Fig. 8A to Fig. 8C and Fig. 9A to Fig.As shown in Figure 9C, a downstream region 160D of the bypass section 160 can be obliquely downstream in the axial direction, so that exhaust gas discharged from the bypass section 160 flows downstream in the axial direction along a passage wall surface 172 that forms the exhaust gas passage 171.

[0096] As described above, when the wastegate valve 55A is open to allow exhaust gas to flow through the wastegate passage 110, the pressure ratio of the turbine 30 generally tends to be high. Therefore, the flow velocity of exhaust gas flowing through the bypass section 160 is relatively high. Consequently, if the bypass section 160 is configured such that the exhaust gas discharged from the bypass section 160 flows downstream in the axial direction along the passage wall surface 172, the exhaust gas discharged from the bypass section 160 imparts momentum to a boundary layer of a turbine diffuser (not shown) connected to the downstream side of the exhaust passage 171. Thus, it is possible to suppress flow separation at the turbine diffuser.

[0097] The present disclosure is not limited to the embodiments described above, but includes modifications of the embodiments described above and embodiments consisting of combinations of these embodiments, as long as these are covered by the attached claims.

[0098] For example, part of the content described in the foregoing embodiments would be understood as follows. (1) A turbine 30 according to at least one embodiment of the present disclosure is provided with: a turbine wheel 3 having a plurality of blades 33; a turbine housing 5 which forms inside a turbine wheel receiving chamber 53 for receiving the turbine wheel 3; and a wastegate valve 55 for controlling a flow rate of exhaust gas flowing through a wastegate passage 110 which is formed inside the turbine housing 5. The wastegate passage 110 is configured to connect a spiral passage 7a formed inside the turbine housing 5 and an area upstream of the trailing edge 37 of each of the plurality of blades 33 in the turbine wheel receiving space 53. A connecting section 120, through which the wastegate passage 110 is connected to the turbine wheel receiving space 53, comprises a plurality of connecting holes 121, 122 arranged at intervals in a circumferential direction.Each of the plurality of connecting holes 121, 122 is oblique to a radial direction of the turbine wheel 3, so that the hole extends downstream in a direction of rotation of the turbine wheel 3 in the direction of a radial inside of the turbine wheel 3.

[0099] With the above configuration (1), the wastegate passage 110 is configured such that exhaust gas flowing through the wastegate passage 110 is directed to a region upstream of the trailing edge 37 of each of the blades 33 in the turbine wheel receiving chamber 53. This causes the exhaust gas in the wastegate passage 110 to flow to the plurality of blades 33 of the turbine wheel 3, so that energy from the exhaust gas can be recovered as kinetic energy of the turbine wheel 3. Consequently, power can be recovered from the exhaust gas flowing through the wastegate passage 110, and the performance of the turbine 30 can be improved by bypassing the wastegate passage 110. Furthermore, by directing the exhaust gas flowing through the wastegate passage 110 to the turbine wheel receiving chamber 53, peak leakage of the exhaust gas through the gap between the tips 34 of the majority of blades 33 and the turbine housing 5 can be suppressed.This can improve the efficiency of turbine 30, and thus the performance of turbine 30 can be improved.

[0100] Another part of the content, which is an alternative to configuration (1) and which is described in the preceding embodiments, would, for example, be understood as follows.

[0101] (2) A turbine 30 according to at least one alternative embodiment of the present disclosure is provided with: a turbine wheel 3 having a plurality of blades 33; a turbine housing 5 which forms inside a turbine wheel receiving chamber 53 for receiving the turbine wheel 3; and a wastegate valve 55, 55A, for controlling a flow rate of exhaust gas flowing through a wastegate passage 110 formed inside the turbine housing. The wastegate passage 110 is configured to connect a spiral passage 7a formed inside the turbine housing 5 and a region 160D upstream of a trailing edge 37, 137 of each of the plurality of blades 33 in the turbine wheel receiving chamber 53. The turbine 30 further comprises a bypass section 160, which is configured to connect the wastegate passage 110 and an exhaust gas passage 171 formed downstream of the turbine wheel 3.The wastegate passage 110 includes an opening 11, which is opened and closed by the wastegate valve 55, 55A. The wastegate valve 55, 55A is configured to adjust the distribution ratio of the exhaust gas flow rate by adjusting the opening degree of the wastegate valve 55, 55A. Specifically, this distribution ratio is the distribution ratio of the exhaust gas flow rate between the flow directed towards the area 160D upstream of the trailing edges 37, 137 of the plurality of blades 33 in the turbine wheel receiving chamber 53 and the flow directed via a bypass section 160 to the exhaust gas passage 171.

[0102] (3) In some embodiments, in the above configuration (1) or (2) the wastegate passage 110 may be configured to connect the spiral passage 7a and a region downstream of the neck section 35 in the turbine wheel receiving space 53.

[0103] As described above, the turbine intake flow rate is generally determined by the flow area of ​​the throat section. Therefore, if the wastegate passage 110 is connected to a region upstream of the throat section 35, the intake flow rate of the turbine 30 may be reduced due to exhaust gas flowing through the wastegate passage 110 into the region upstream of the throat section 35.

[0104] Therefore, as in the configuration described above (3), by connecting the wastegate passage 110 to a region downstream of the throat section 35, even if the exhaust gas flowing through the wastegate passage 110 enters the turbine wheel receiving chamber 53, the influence on the intake flow rate of the turbine 30 can be suppressed. Furthermore, by connecting the wastegate passage 110 to a region downstream of the throat section 35, compared to connecting the wastegate passage 110 to a region upstream of the throat section 35, the exhaust gas can be discharged more efficiently via the wastegate passage 110 to the downstream side of the turbine 30.

[0105] (4) In some embodiments, in the above configuration (1), (2) or (3), the turbine wheel 3 may further comprise a plurality of divider blades 133 arranged between the plurality of blades 33 and configured such that the trailing edge 137 of each of the plurality of divider blades 133 is located on the leading edge side 36 relative to the trailing edge 37 of each of the plurality of blades 33. The wastegate passage 110 may be configured to connect the spiral passage 7a and a region downstream of the trailing edge 137 of each of the divider blades 133 and upstream of the trailing edge 37 of each of the plurality of blades 33 in the turbine wheel receiving space 53.

[0106] If the throat section 35 exists within the area of ​​existence of the divider blade 133 in the flow passage formed between two circumferentially adjacent blades 33, the wastegate passage 110 is connected to a region downstream of the throat section 35 by assuming the configuration (4) described above. Thus, even if the exhaust gas that has flowed through the wastegate passage 110 enters the turbine wheel intake chamber 53, its influence on the turbine's intake flow rate can be suppressed. Furthermore, by connecting the wastegate passage 110 to an area downstream of the trailing edge 137 of the divider blade 133, compared to the case where the wastegate passage 110 is connected to an area upstream of the trailing edge 137 of the divider blade 133, the exhaust gas can be efficiently discharged via the wastegate passage 110 to the downstream side of the turbine 30.Furthermore, since the turbine wheel 3 has the majority of divider blades 133, the performance of the turbine 30 can be improved even if exhaust gas does not flow through the wastegate passage 110.

[0107] As already mentioned, the above configuration (1) includes a connecting section 120 through which the wastegate passage 110 is connected to the turbine wheel receiving chamber 53, and a plurality of connecting holes 121, 122 arranged at intervals in the circumferential direction.

[0108] This allows the exhaust gas in the wastegate passage 110 to flow through the plurality of connecting holes 121, 122 to the plurality of blades 33 of the turbine wheel 3, thereby ensuring the velocity of exhaust gas that is blown out of the plurality of connecting holes 121, 122.

[0109] (5) In some embodiments, in the above configuration (2) a connecting section 120, through which the wastegate passage 110 is connected to the turbine wheel receiving space 53, may include a groove 125 extending along the circumferential direction.

[0110] With the above configuration (5) the exhaust gas can flow through the groove 125 in the wastegate passage 110, which extends circumferentially to the majority of blades 33 of the turbine wheel 3, suppressing vibration of the blades 33 and improving the reliability of the turbine 30.

[0111] (6) In some embodiments, in the above configuration (5) the wastegate passage 110 may comprise a spiral section 150 configured to have a cross-sectional area decreasing downstream in the direction of rotation R of the turbine wheel 3 and communicating with the turbine wheel receiving space 53 through the groove 125.

[0112] With the above configuration (6), the spiral section 150 guides the exhaust gas along the circumferential direction, thereby suppressing the difference in the flow rate of exhaust gas flowing into the turbine wheel receiving chamber 53 through the groove 125, depending on the circumferential position. As a result, it is possible to further improve the performance of the turbine 30 by bypassing exhaust gas to the wastegate passage 110.

[0113] (7) In some embodiments, in the above configuration (6) the turbine may further be provided with a plurality of nozzle elements 131, 132 which are arranged in the groove 125 at intervals in the circumferential direction and are configured to guide exhaust gas passing through the groove 125 to flow downstream in the direction of rotation R of the turbine wheel 3 as the exhaust gas moves inwards in the radial direction.

[0114] With the above configuration (7), the majority of nozzle elements 131, 132 guide the exhaust gas as described above, so that the exhaust gas can flow efficiently into the turbine wheel receiving chamber 53. As a result, it is possible to further improve the performance of the turbine 30 by bypassing exhaust gas to the wastegate passage 110.

[0115] (8) In some embodiments, in the above configuration (1) the connecting section 120 may have a convergent-divergent shape.

[0116] Generally, when the wastegate valve 55, 55A is open to allow exhaust gas to flow through the wastegate passage 110, the pressure ratio of the turbine 30 tends to be high. Therefore, the flow velocity of exhaust gas passing through the connecting section 120 is very high. Thus, with the configuration described above (8), since the connecting section 120 has a convergent-divergent or de Laval nozzle shape, energy from exhaust gas expelled from the connecting section 120 can be efficiently converted into kinetic energy of the turbine wheel 3. Consequently, it is possible to further improve the performance of the turbine 30 by bypassing exhaust gas to the wastegate passage 110. Furthermore, since it is relatively easy to machine the connecting section 120 into a convergent-divergent shape, manufacturing costs can be reduced.

[0117] As already mentioned, in the above configuration (2) the turbine further comprises a bypass section 160 which is configured to connect the wastegate passage 110 and an exhaust gas passage 171 formed downstream of the turbine wheel 3.

[0118] This makes it possible to increase the flow rate of exhaust gas passing through wastegate passage 110. Furthermore, even if the amount of supplied exhaust gas exceeds the amount required to drive compressor 40, the excess exhaust gas from turbine 30 can be bypassed. Consequently, bypassing exhaust gas to wastegate passage 110 improves the performance of turbine 30 and suppresses excessive turbine 30 rotation, thus improving turbine 30 reliability.

[0119] (9) In some embodiments, in the configuration (2) above, the wastegate valve 55, 55A may comprise a pivoting valve whose radially outer position is pivotably supported by the turbine housing 5. The connecting section 120, through which the wastegate passage 110 communicates with the turbine wheel receiving chamber 53, may be arranged upstream of the opening 111 in the axial direction. The bypass section 160 may be arranged downstream of the opening 111 in the axial direction.

[0120] With the above configuration (9), if the opening degree of the wastegate valve 55 is relatively small, the flow of exhaust gas from the opening 111 to the bypass section 160 is blocked by the wastegate valve 55, so that the exhaust gas flows to the connecting section 120. Therefore, if the opening degree of the wastegate valve 55 is relatively small, the exhaust gas flows from the opening 111 mainly to the connecting section 120.

[0121] If the opening degree of the wastegate valve 55 is relatively large, it is less likely that the exhaust gas flow from the opening 111 to the bypass section 160 will be blocked by the wastegate valve 55, allowing the exhaust gas to flow easily to the bypass section 160. Therefore, if the opening degree of the wastegate valve 55 is relatively large, the exhaust gas from the opening 111 flows not only to the connecting section 120 but also to the bypass section 160.

[0122] Thus, the distribution ratio of the exhaust gas flowing to the connecting section 120 and the bypass section 160 can be adjusted by the opening degree of the wastegate valve 55. Consequently, it is possible to further improve the performance of the turbine 30 by bypassing exhaust gas to the wastegate passage 110, and it is possible to suppress excessive turbine rotation to improve the reliability of the turbine 30.

[0123] (10) In some embodiments, in the above configuration (2), the wastegate valve 55A may be configured to be movable in the axial direction. The connecting section 120, through which the wastegate passage 110 communicates with the turbine wheel receiving chamber 53, may be arranged upstream of the opening 111 in the axial direction. The bypass section 160 may be arranged downstream of the opening 111 in the axial direction.

[0124] With the above configuration (10), if the opening degree of the wastegate valve 55A is relatively small, the flow of exhaust gas from the opening 111 to the bypass section 160 is blocked by the wastegate valve 55A, so that the exhaust gas flows to the connecting section 120. Therefore, if the opening degree of the wastegate valve 55A is relatively small, the exhaust gas flows from the opening 111 mainly to the connecting section 120.

[0125] If the opening degree of the wastegate valve 55A is relatively large, it is less likely that the exhaust gas flow from the opening 111 to the bypass section 160 will be blocked by the wastegate valve 55A, allowing the exhaust gas to flow easily to the bypass section 160. Therefore, if the opening degree of the wastegate valve 55A is relatively large, the exhaust gas from the opening 111 flows not only to the connecting section 120 but also to the bypass section 160.

[0126] Thus, the distribution ratio of the exhaust gas flowing to the connecting section 120 and the bypass section 160 can be adjusted by the opening degree of the wastegate valve 55A. Consequently, it is possible to further improve the performance of the turbine 30 by bypassing exhaust gas to the wastegate passage 110, and it is possible to suppress excessive turbine rotation to improve the reliability of the turbine 30.

[0127] (11) A turbocharger 1 according to at least one embodiment of the present disclosure is provided with the turbine 30 according to one of the preceding configurations (1) to (10).

[0128] With the above configuration (11) it is possible to provide the turbocharger 1 with improved part-load performance of the turbine 30. Reference symbol list 1 turbocharger 3 Turbine wheel 5 Housings (turbine housings) 7 Spiral section 7a Spiral passage 30 Turbine 33 Bucket (rotor bucket) 34 Top section (peak) 35 Neck section 36 Front edge 37 trailing edge 53 Turbine wheel mounting space 55, 55A Wastegate valve 110 Wastegate passage 111 Opening 120 connecting section 121, 122 Connecting hole 125 Nut 131, 132 Nozzle element 133 Dividing bucket 137 trailing edge 140 nozzle section 160 Bypass section 171 Exhaust gas passage

Claims

[1] Turbine (30), comprising: a turbine wheel (3) with a plurality of blades (33); a turbine housing (5) which forms an internal turbine wheel receiving chamber (53) for receiving the turbine wheel (3); and a wastegate valve (55) for controlling a flow rate of exhaust gas flowing through a wastegate passage (110) formed inside the turbine housing (5), wherein the wastegate passage (110) is configured to connect a spiral passage (7a) formed inside the turbine housing (5) and a region (160D) upstream of a trailing edge (37) of each of the plurality of blades (33) in the turbine wheel receiving space (53), wherein a connecting section (120) through which the wastegate passage (110) is connected to the turbine wheel receiving space (53) comprises a plurality of connecting holes (121, 122) which are arranged at intervals in a circumferential direction, and wherein each of the plurality of connecting holes (121, 122) is inclined to a radial direction of the turbine wheel (3), such that the respective connecting hole (121, 122) extends downstream in a direction of rotation of the turbine wheel (3) in the direction of a radial inside of the turbine wheel (3). [2] Turbine (30), comprising: a turbine wheel (3) with a plurality of blades (33); a turbine housing (5) which forms an internal turbine wheel receiving chamber (53) for receiving the turbine wheel (3); and a wastegate valve (55, 55A) for controlling a flow rate of exhaust gas flowing through a wastegate passage (110) formed inside the turbine housing (5), wherein the wastegate passage (110) is configured to connect a spiral passage (7a) formed inside the turbine housing (5) and a region (160D) upstream of a trailing edge (37) of each of the plurality of blades (33) in the turbine wheel receiving space (53), wherein the turbine (30) further comprises a bypass section (160) configured to connect the wastegate passage (110) and an exhaust gas passage (171) formed downstream of the turbine wheel (3), wherein the wastegate passage (110) includes an opening (111) which is opened and closed by the wastegate valve (55, 55A), wherein the wastegate valve (55, 55A) is configured to set a distribution ratio of the exhaust gas flow rate by an opening degree of the wastegate valve (55, 55A) which is a distribution ratio of the exhaust gas flow rate between the flow directed towards the area (160D) upstream of the trailing edges (37) of the plurality of blades (33) in the turbine wheel receiving space (53) and the flow directed via a bypass section (160) to the exhaust gas passage (171). [3] Turbine (30) according to claim 2, wherein the wastegate valve (55, 55A) is configured such that it at an opening degree that is smaller than a specified opening degree, the exhaust gas from the opening (111) into the area (160D) upstream of the trailing edges (37) allows the majority of blades (33) to flow in the turbine wheel receiving chamber (53), while blocking the flow of exhaust gas from the opening (111) to the exhaust gas passage (171) via bypass section (160), and at an opening degree that is equal to or greater than the predetermined opening degree, the exhaust gas flows from the opening (111) into the area (160D) upstream of the trailing edges (37) of the plurality of blades (33) in the turbine wheel (3), while the exhaust gas from the opening (111) can also flow via the bypass section (160) to the exhaust gas passage (171). [4] Turbine (30) according to claim 1 or 2, wherein the wastegate passage (110) is configured to connect the spiral passage (7a) and a region downstream of a neck section (35) in the turbine wheel receiving space. [5] Turbine (30) according to claim 1 or 2, wherein the turbine wheel (3) further comprises a plurality of divider blades arranged between the plurality of blades (33) and designed such that a trailing edge (137) of each of the plurality of divider blades is arranged on a leading edge side (36) in relation to the trailing edge (37) of each of the plurality of blades (33), and wherein the wastegate passage (110) is configured to connect the spiral passage (7a) and a region (160D) downstream of the trailing edge (137) of each of the plurality of divider blades and upstream of the trailing edge (37) of each of the plurality of blades (33) in the turbine wheel receiving space (53). [6] Turbine (30) according to claim 2, wherein a connecting section (120) through which the wastegate passage (110) is connected to the turbine wheel receiving space (53) comprises a groove (125) extending along a circumferential direction. [7] Turbine (30) according to claim 6, wherein the wastegate passage (110) comprises a spiral section (150) configured to have a cross-sectional area that decreases downstream in a direction of rotation of the turbine wheel (3) and is connected to the turbine wheel receiving space (53) through the groove (125). [8] Turbine (30) according to claim 6, further comprising a plurality of nozzle elements (131, 132) arranged in the groove (125) at intervals in a circumferential direction and configured to guide exhaust gas passing through the groove (125) to flow downstream in a direction of rotation of the turbine wheel (3) when the exhaust gas moves inwards in a radial direction. [9] Turbine (30) according to claim 1, wherein the connecting section (120) has a convergent-divergent shape. [10] Turbine (30) according to claim 2, wherein the wastegate valve (55, 55A) comprises a pivoting valve whose radially outer position is pivotably supported by the turbine housing (5), wherein a connecting section (120), through which the wastegate passage (110) is connected to the turbine wheel receiving chamber (53), is arranged upstream of the opening (111) in an axial direction, and wherein the bypass section (160) is arranged downstream of the opening (111) in the axial direction. [11] Turbine (30) according to claim 2, wherein the wastegate valve (55, 55A) is configured to be movable in an axial direction, wherein a connecting section (120), through which the wastegate passage (110) is connected to the turbine wheel receiving chamber (53), is arranged upstream of the opening (111) in the axial direction, and wherein the bypass section (160) is arranged downstream of the opening (111) in the axial direction. [12] Turbocharger (1) comprising the turbine (30) according to claim 1 or 2.

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