Turbocharger turbine housing

Abstract

To improve the performance of a wastegate assembly and the entire turbocharger by reducing heat deformation.SOLUTION: A turbine housing includes a turbine inlet wall defining an inlet passage, an exducer shroud wall defining an exducer interior, a turbine outlet wall defining an outlet passage, a wastegate port wall defining a wastegate channel, a bushing wall coupled to the wastegate port wall and defining a bushing boss extending along a bushing axis, and a valve seat disposed around the wastegate channel. The wastegate port wall is disposed outside of the exducer interior such that the wastegate port wall and the bushing wall is thermally separated from the turbine inlet wall and such that relative displacement between the valve seat and the bushing axis is reduced during operation of the turbocharger.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates generally to turbine housings, and more specifically to turbochargers that include a wastegate assembly and a turbine housing. [Background technology]

[0002] A turbocharger receives exhaust gases from an internal combustion engine and delivers compressed air to the internal combustion engine. Turbochargers are used to increase the power output of an internal combustion engine, reduce the fuel consumption of the internal combustion engine, and reduce the emissions produced by the internal combustion engine. The delivery of compressed air to an internal combustion engine by a turbocharger allows the internal combustion engine to be smaller yet produce the same or nearly the same amount of horsepower as a larger naturally aspirated internal combustion engine. Using a smaller internal combustion engine in a vehicle reduces the mass and aerodynamic frontal area of ​​the vehicle, which helps reduce the fuel consumption of the internal combustion engine and improve the fuel economy of the vehicle.

[0003] A conventional turbocharger includes a turbine housing with a turbine inlet wall defining an inlet passage in fluid communication with the internal combustion engine for receiving exhaust gases from the internal combustion engine, an exducer shroud wall disposed downstream of the inlet passage and defining an exducer (gas exhaust) interior in fluid communication therewith for receiving the exhaust gases from the inlet passage, and a turbine outlet wall disposed downstream of the exducer interior and in fluid communication therewith for defining an outlet passage for receiving the exhaust gases from the exducer interior.

[0004] The conventional turbine housing further includes a wastegate port wall disposed downstream of the inlet passage and in fluid communication therewith to define a wastegate channel for discharging exhaust gases from the inlet passage to an outlet passage by bypassing the exducer interior. The wastegate port wall is disposed downstream of the wastegate channel and defines a wastegate channel outlet for discharging exhaust gases to the outlet passage. The typical turbine housing also includes a bushing wall coupled to the wastegate port wall, the bushing wall defining a bushing boss extending along a bushing axis. The bushing wall is spaced from the turbine inlet wall such that the wastegate port wall is disposed between the bushing wall and the turbine inlet wall. The conventional turbine housing further includes a valve seat disposed about the wastegate channel at a wastegate channel outlet of the wastegate channel.

[0005] A typical turbocharger additionally includes a wastegate assembly for controlling the flow of exhaust gas through a wastegate channel. A conventional wastegate assembly includes a valve element engageable with a valve seat and movable between a first position for preventing the flow of exhaust gas from the inlet passage to the outlet passage by bypassing the exducer interior and a second position for allowing the flow of exhaust gas from the inlet passage to the outlet passage by bypassing the exducer interior.

[0006] In a typical turbine housing, thermal deformation of the turbine housing can cause relative movement between various features of the turbocharger, resulting in reduced performance and sometimes turbocharger failure. For example, movement of the valve element relative to the valve seat due to different thermal deformation rates of the turbine housing can lead to reduced performance of the wastegate assembly and the entire turbocharger. Specifically, as the bushing wall and the wastegate port wall thermally deform at different thermal deformation rates relative to each other, the valve element can no longer properly engage the valve seat to seal the wastegate channel, resulting in reduced performance of the turbocharger and inability for the turbocharger to operate over the full operating range of the internal combustion engine. In particular, the valve element can no longer correctly move to a first position to seal the wastegate channel by engaging the valve seat, the rotational speed of the turbine wheel within the exducer interior cannot reach the rotation target as a result of poor sealing of the wastegate channel, and the internal combustion engine cannot achieve its performance target due to poor performance of the entire turbocharger. These problems are caused in part by the wastegate port wall being located on the exducer shroud wall in a conventional turbine housing. In other words, the exducer shroud wall couples the bushing wall to the turbine inlet wall such that the exducer shroud wall is disposed between the bushing wall and the turbine inlet wall. In such a configuration, the wastegate port wall is exposed to the hottest flow of exhaust gas as a result of being disposed within the exducer interior. Exposing the wastegate port wall to the hottest flow of exhaust gas results in the wastegate port having a greater thermal deformation than the bushing wall, resulting in relative movement between the valve element and the valve seat, leading to a sealing failure of the wastegate channel.

[0007] Therefore, there remains a need to provide an improved turbine housing for a turbocharger. Summary of the Invention [Problem to be solved by the invention]

[0008] A turbocharger for receiving exhaust gas from an internal combustion engine of a vehicle and delivering compressed air to the internal combustion engine includes a turbine housing. The turbine housing includes a turbine inlet wall configured to be in fluid communication with the internal combustion engine and defining an inlet passage for receiving the exhaust gas from the internal combustion engine, an exducer shroud wall disposed downstream of the inlet passage and in fluid communication therewith defining an exducer interior for receiving the exhaust gas from the inlet passage, and a turbine outlet wall disposed downstream of the exducer interior and in fluid communication therewith defining an outlet passage for receiving the exhaust gas from the exducer interior. The turbine housing also includes a wastegate port wall disposed downstream of the inlet passage and in fluid communication therewith defining a wastegate channel for discharging the exhaust gas from the inlet passage to an outlet passage by bypassing the exducer interior. The wastegate port wall defines a wastegate channel outlet disposed downstream of the wastegate channel for discharging the exhaust gas to an outlet passage. The turbine housing further includes a bushing wall coupled to the wastegate port wall and defining a bushing boss extending along the bushing axis. The bushing wall is spaced from the turbine inlet wall such that the wastegate port wall is disposed between the bushing wall and the turbine inlet wall. The turbine housing also includes a valve seat disposed about the wastegate channel at a wastegate channel outlet of the wastegate channel. The turbocharger also includes a wastegate assembly for controlling the flow of exhaust gases through the wastegate channel. The wastegate assembly includes a valve element engageable with the valve seat. The valve element is movable between a first position for preventing the flow of exhaust gases from the inlet passage to the outlet passage by bypassing the exducer interior and a second position for allowing the flow of exhaust gases from the inlet passage to the outlet passage by bypassing the exducer interior.The wastegate port wall is disposed outside the exducer interior such that the wastegate port wall and the bushing wall are thermally isolated from the turbine inlet wall and such that relative displacement between the valve seat and the bushing shaft is reduced during operation of the turbocharger.

[0009] Thus, configuring the wastegate port wall and the bushing wall to be thermally isolated from the turbine inlet wall and locating the wastegate port wall outside the exducer interior to reduce relative displacement between the valve seat and the bushing axis during operation of the turbocharger improves the performance of the wastegate assembly and the turbocharger. Locating the wastegate port wall outside the exducer interior allows the wastegate port wall to be exposed to the external environment, which results in cooling of the wastegate port wall and reduced thermal deformation of the wastegate port wall. Reducing the thermal deformation of the bushing wall and the wastegate port wall improves the performance of the wastegate assembly and the turbocharger as a whole. Specifically, as the thermal deformation of the bushing wall and the wastegate port wall is reduced, the valve element can improve sealing of the wastegate channel by engaging the valve seat, which improves the performance of the turbocharger and allows the turbocharger to operate over the full operating range of the internal combustion engine. In particular, the valve element can be accurately moved to a first position to seal the wastegate channel, the rotational speed of the turbine wheel in the exducer interior can reach a rotation target, and the internal combustion engine can achieve a performance target through the performance of the turbocharger. [Brief description of the drawings]

[0010] Other advantages of the present invention will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in conjunction with the accompanying drawings, in which:

[0011] [Figure 1]FIG. 1 is a perspective view of a turbocharger turbine housing and wastegate assembly. [Diagram 2] FIG. 2 is a cross-sectional view of a turbine housing including an exducer shroud wall that defines an exducer interior and a wastegate port wall that defines a wastegate channel. [Diagram 3] FIG. 3 is a cross-sectional view of a turbine housing including an outlet wall defining an outlet passage, a bushing wall defining a bushing boss, and a valve seat. [Figure 4] FIG. 4 is a partial phantom view of a turbine housing with the wastegate port wall disposed outside the exducer interior. [Diagram 5] FIG. 5 is a cross-sectional view of a turbine housing in which the valve seat extends along a valve seat plane and the bushing axis and the valve seat plane define a distance therebetween. [Figure 6] FIG. 6 is a schematic diagram of a turbocharger including a bearing housing connected to the turbine housing and defining a bearing housing interior, a compressor housing connected to the bearing housing and defining a compressor housing interior, a shaft rotatably connected to the turbine wheel and disposed in the bearing housing interior, and a compressor wheel rotatably connected to the shaft and disposed in the compressor housing interior. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Referring to the drawings, in which like numerals indicate like parts throughout the several views, a turbocharger 20, shown generally in FIG. 6, for receiving exhaust gases from an internal combustion engine of a vehicle and delivering compressed air to the internal combustion engine, includes a turbine housing 22, shown in FIGS. 1-5. With particular reference to FIG. 3, the turbine housing 22 includes a turbine inlet wall 24 configured for fluid communication with the internal combustion engine and defining an inlet passage 26 for receiving exhaust gases from the internal combustion engine. The inlet passage 26 may be a single scroll inlet passage, or may be a multiple scroll passage, such as a twin scroll configuration, as shown in FIG. 5. With reference to FIGS. 1-4, the turbine housing 22 also includes an exducer shroud wall 28 disposed downstream of the inlet passage 26 and in fluid communication therewith defining an exducer interior 30 for receiving exhaust gases from the inlet passage 26. The turbine housing 22 further includes a turbine exit wall 32 disposed downstream of and in flow communication with the exducer interior 30 defining an exit passage 34 for receiving exhaust gases from the exducer interior 30 .

[0013] The turbine housing 22 additionally includes a wastegate port wall 36 disposed downstream of the inlet passage 26 and in fluid communication therewith to define a wastegate channel 38 for discharging exhaust gases from the inlet passage 26 to the outlet passage 34 by bypassing the exducer interior 30. The wastegate port wall 36 defines a wastegate channel outlet 40 disposed downstream of the wastegate channel 38 for discharging exhaust gases into the outlet passage 34, as shown in FIG. 3. The turbine housing 22 further includes a bushing wall 42 coupled to the wastegate port wall 36 and defining a bushing boss 44 extending along a bushing axis BA. The bushing wall 42 is spaced from the turbine inlet wall 24 such that the wastegate port wall 36 is disposed between the bushing wall 42 and the turbine inlet wall 24. The turbine housing 22 also includes a valve seat 46 disposed about the wastegate channel 38 at the wastegate channel outlet 40 of the wastegate channel 38. Typically, the valve seat 46 is located in the outlet passage 34 .

[0014] The turbocharger 20 also includes a wastegate assembly 48 for controlling the flow of exhaust gases through the wastegate channel 38. The wastegate assembly 48 includes a valve element 50 engageable with the valve seat 46. The valve element 50 is movable between a first position and a second position. When the valve element 50 is in the first position, the valve element 50 prevents exhaust gases from flowing from the inlet passage 26 to the outlet passage 34 by bypassing the exducer interior 30. When the valve element 50 is in the second position, the valve element 50 allows exhaust gases to flow from the inlet passage 26 to the outlet passage 34 by bypassing the exducer interior 30. The turbocharger 20 typically includes an actuator 52 coupled to the valve element 50 for moving the valve element 50 between the first position and the second position.

[0015] The wastegate port wall 36 is configured to be disposed externally of the exducer interior 30, i.e., disposed outside of the exducer interior 30, such that the wastegate port wall 36 and the bushing wall 42 are thermally isolated from the turbine inlet wall 24, and such that the relative displacement between the valve seat 46 and the bushing axis BA is reduced during operation of the turbocharger 20. Thermally isolating the wastegate port wall 36 and the bushing wall 42 from the turbine inlet wall 24 typically allows the wastegate port wall 36 and the bushing wall 42 to thermally expand at a lower rate than the turbine inlet wall 24 during operation of the turbocharger 20, which reduces the relative displacement between the valve seat 46 and the bushing axis BA. Additionally, the turbine inlet wall 24 typically expands and contracts at a higher rate than the wastegate port wall 36 and the bushing wall 42 as a result of the wastegate port wall 36 being disposed outside of the exducer interior 30. As shown in FIG. 4, the entire turbine housing is shown in phantom, with the wastegate channel 38 and wastegate port wall 36 shown in solid lines and disposed outside the exducer interior 30.

[0016] Configuring the wastegate port wall 36 and the bushing wall 42 to thermally isolate the wastegate port wall 36 from the turbine inlet wall 24 and locating the wastegate port wall 36 outside the exducer interior 30 to reduce the relative displacement between the valve seat 46 and the bushing axis BA during operation of the turbocharger 20 improves the performance of the wastegate assembly 48 and the turbocharger 20. Specifically, thermal deformation between the bushing wall 42, and therefore various features of the turbocharger 20, such as the bushing axis BA, and the valve seat 46 is reduced. Locating the wastegate port wall 36 outside the exducer interior 30 allows the wastegate port wall 36 to be exposed to the external environment, which results in cooling of the wastegate port wall 36 and reduced thermal deformation of the wastegate port wall 36. Reducing the relative displacement between the bushing wall 42, and therefore the bushing axis BA, and the wastegate port wall 36 improves the performance of the wastegate assembly 48 and the turbocharger 20 as a whole. Specifically, as the relative displacement between the bushing axis BA and the valve seat 46 decreases, the valve element 50 can engage the valve seat 46 to improve sealing of the wastegate channel 38, resulting in improved performance of the turbocharger 20 and allowing the turbocharger 20 to operate over the full range of the internal combustion engine. In particular, the valve element 50 can move to the first position to fully engage and seal with the wastegate channel 38 at the appropriate time, allowing the speed of the turbine wheel 68 within the exducer interior 30 to reach the rotation target, and the internal combustion engine to achieve its performance target with the improved performance of the turbocharger 20.

[0017] Typically, the wastegate port wall 36 extends between the turbine inlet wall 24 and the turbine outlet wall 32. In such an embodiment, the wastegate port wall 36 is typically spaced apart from the exducer shroud wall 28. In other words, the wastegate port wall 36 may protrude from the turbine inlet wall 24 and the exducer shroud wall 28. Having the wastegate port wall 36 protrude from the turbine inlet wall 24 and the exducer shroud wall 28 allows the wastegate port wall 36 to be exposed to external cooling air. Additionally, having the wastegate port wall 36 protrude from the turbine inlet wall 24 and the exducer shroud wall 28 allows the wastegate port wall 36 to be disposed between and connected to the bushing wall 42 and the turbine inlet wall 24.

[0018] The bushing wall 42 may be directly coupled to the wastegate port wall 36. In other words, the wastegate port wall 36 is disposed between the bushing wall 42 and the turbine inlet wall 24, such that the bushing wall 42 is separated from the turbine inlet wall 24. If the bushing wall 42 is directly coupled to the wastegate port wall 36, the wastegate port wall 36 is typically directly coupled to the turbine inlet wall 24. In such an embodiment, the exducer shroud wall 28 does not couple the bushing wall 42 to the turbine inlet wall 24. In other words, the exducer shroud wall 28 is not disposed between the bushing wall 42 and the turbine inlet wall 24. Rather, the wastegate port wall 36 is disposed between the bushing wall 42 and the turbine inlet wall 24. Directly coupling the bushing wall 42 and the wastegate port wall 36 to one another allows the wastegate port wall 36 and the bushing wall 42 to thermally expand at the same rate during operation of the turbocharger 20. Additionally, when the wastegate port wall 36 and the bushing wall 42 are directly connected to one another, the wastegate port wall 36 and the bushing wall 42 may be integral with one another, i.e., one piece. When the wastegate port wall 36 and the bushing wall 42 are directly connected to one another such that they thermally expand at the same rate during operation of the turbocharger 20, the performance of the turbocharger 20 is improved, particularly due to the sealing of the wastegate channel 38 by the valve element 50. Specifically, because the wastegate port wall 36 and the bushing wall 42 are able to thermally expand at the same rate during operation of the turbocharger 20, the valve element 50 is able to improve the sealing of the wastegate channel 38 because the relative movement of the valve seat 46 and the bushing axis BA, and therefore the valve element 50, relative to one another is significantly reduced. The improved sealing of the wastegate channel 38 improves the performance of the turbocharger 20 as the amount of exhaust gas passing through the wastegate channel 38 when the valve element 50 is in the first position is significantly reduced, if not eliminated.

[0019] 1, the valve element 50 may be further defined as a valve body 54 and a wastegate arm 56 extending away from the valve body 54. If present, the wastegate arm 56 is typically rotated by a spindle (not shown) that extends through the bushing boss 44 and extends along the spindle axis SA. When the wastegate arm 56 extends through the bushing boss 44, the wastegate arm extends along the spindle axis SA. The wastegate assembly 48 may include a bushing 58 disposed in the bushing boss 44 for supporting the wastegate arm 56. If present, the valve body 54 is configured to engage the valve seat 46 when the valve element 50 is in a first position to prevent exhaust gases from flowing through the wastegate channel 38, and the valve body 54 is configured to disengage from the valve seat 46 when the valve element 50 is in a second position to allow exhaust gases to flow through the wastegate. Typically, the actuator 52 is coupled to a wastegate arm 56 for moving the valve body 54 between engagement and disengagement with the valve seat 46 .

[0020] In one embodiment, the valve body 54 and the wastegate arm 56 are rigidly coupled to one another such that the valve body 54 and the wastegate arm 56 are configured to move simultaneously with one another as the valve element 50 moves between the first and second positions. In embodiments in which the wastegate arm 56 is rigidly coupled to the valve body 54, the wastegate arm 56 may be welded to the valve body 54. When the valve body 54 and the wastegate arm 56 are rigidly coupled to one another, having the wastegate port wall 36 outboard of the exducer interior 30 and configuring the wastegate port wall 36 and bushing wall 42 to thermally isolate from the turbine inlet wall 24 to reduce relative displacement between the valve seat 46 and the bushing axis BA provides several advantages.

[0021] First, because the wastegate arm 56 and the valve body 54 are rigidly coupled to one another, there is no need for part tolerances between the wastegate arm 56 and the valve body 54. To this end, the design and manufacturing costs of the wastegate arm 56 and the valve body 54 are significantly reduced. In such an embodiment, thermal deformation of various portions of the turbine housing 22, such as the turbine inlet wall 24, the wastegate port wall 36, and the bushing wall 42, may adversely affect the ability of the valve element 50 to adequately seal the wastegate channel 38 when the wastegate arm 56 and the valve body 54 are rigidly coupled to one another. However, configuring the wastegate port wall 36 and the bushing wall 42 to thermally isolate them from the turbine inlet wall 24 and disposing them outside the exducer interior 30 to reduce relative displacement between the valve seat 46 and the bushing axis BA during operation of the turbocharger 20 results in the rigidly connected wastegate arm 56 and valve body 54 adequately sealing the wastegate channel 38 despite thermal deformation of the wastegate port wall 36 and the bushing wall 42. Second, in embodiments where the bushing wall 42 and the wastegate port wall 36 are directly connected to one another and the wastegate arm 56 and the valve body 54 are rigidly connected to one another, the bushing wall 42 and the wastegate port wall 36 expand and contract at the same rate. When the bushing wall 42 and the wastegate port wall 36 expand and contract at the same rate, the bushing axis BA and the valve seat 46 experience minimal relative movement with respect to one another, resulting in better sealing of the wastegate channel 38, as described below.

[0022] Referring to FIG. 5, the wastegate arm 56 may extend along a bushing axis BA, and the valve seat 46 may extend along a valve seat plane VSP. In one embodiment, the bushing axis BA and the valve seat plane VSP define a distance D therebetween. As described above, as a result of disposing the wastegate port wall 36 outside the exducer interior 30, the relative movement between the valve seat 46 and the bushing axis BA is reduced. When the relative movement between the valve seat 46 and the bushing axis BA is reduced, the relative movement between the wastegate arm 56 and the valve seat 46 is also reduced. As shown in FIG. 5, the wastegate port wall 36 may be directly coupled to the bushing wall 42. When the wastegate port wall 36 and the bushing wall 42 are directly coupled to each other, the relative displacement between the valve seat 46 and the bushing axis BA is reduced. In particular, when the wastegate port wall 36 and the bushing wall 42 are directly connected to one another, the valve seat 46 is adjacent to the bushing wall 42 which defines the bushing bore 44, thereby reducing relative deformation between the valve seat 46 and the bushing axis BA, as described below.

[0023] The thermal growth of the various components of the turbine housing 22, such as the bushing wall 42 and the wastegate port wall 36, is based on the formula: Thermal Growth = Thermal Expansion Coefficient * Temperature * Length. In this formula, the length is the only parameter that can be practically changed in the above formula. In other words, since the turbine housing is typically made of a metal with a high thermal expansion coefficient, it is impractical for the thermal expansion coefficient to change, and since the turbine housing 22 is exposed to high temperature exhaust gases, it is impractical for the temperature to change. For this purpose, as shown in FIG. 5, a distance D between the bushing axis BA and the valve seat 46 plane is shown. Additionally, in FIG. 5, the distance D is defined as the distance between the spindle axis SA and the valve seat plane VSP. The distance D between the spindle axis SA and the valve seat plane VSP can be adjusted accordingly. In particular, when the wastegate port wall 36 and the bushing wall 42 are directly connected to each other, the relative displacement between the valve seat 46 and the bushing axis BA is reduced because the valve seat 46 is adjacent to the bushing wall 42 that defines the bushing bore. This reduces the relative deformation between the valve seat 46 and the bushing axis BA. As a non-limiting example, the distance D may be in the range of 0 to 30 millimeters. As another non-limiting example, the distance D may be 30 millimeters or less. By making the distance D less than 30 millimeters, the relative deformation between the valve seat 46 and the bushing axis BA is reduced, which in turn results in a better seal of the wastegate channel 38 when the valve element 50 is in the first position. As another non-limiting example, the distance D may be 20 millimeters or less. By making the distance D less than 20 millimeters, the relative deformation between the valve seat 46 and the bushing axis BA is reduced, which in turn results in a better seal of the wastegate channel 38 when the valve element 50 is in the first position. As another non-limiting example, the distance D may be 15 millimeters or less.By making the distance D less than 15 millimeters, the relative deformation between the valve seat 46 and the bushing axis BA is reduced, which in turn results in a better seal of the wastegate channel 38 when the valve element 50 is in the first position. As another non-limiting example, the distance D may be 12.5 millimeters. By making the distance D 12.5 millimeters, the relative deformation between the valve seat 46 and the bushing axis BA is reduced, which in turn results in a better seal of the wastegate channel 38 when the valve element 50 is in the first position.

[0024] As shown in FIGS. 3 and 5 , the turbine housing 22 may have a platform surface 60 that extends parallel to the valve seat 46. In one embodiment, the valve seat 46 may be flush with the platform surface 60. Having the valve seat 46 flush with the platform surface 60 helps to reduce the distance D between the bushing axis BA and the valve seat plane VSP because the wastegate port wall 36 does not extend past the platform surface 60 into the outlet passage 34. In another embodiment, the platform surface 60 defines a recess 62. If the recess 62 is present, the valve seat 46 may be disposed within the recess 62. Having the valve seat 46 flush with the platform surface 60 or having the valve seat 46 disposed within the recess 62 helps to reduce the distance D, thus reducing thermal deformation of the wastegate port wall 36 and the bushing wall 42.

[0025] As shown in FIG. 3, the wastegate channel 38 may be further defined as a first wastegate channel 64, and the wastegate port wall 36 may further define a second wastegate channel 66 in fluid communication with the inlet passage 26 for exhausting exhaust gases from the inlet passage 26 by bypassing the exducer interior 30.

[0026] 6, turbocharger 20 may include a turbine wheel 68 disposed within exducer interior 30. Turbocharger 20 may also include a bearing housing 70 coupled to turbine housing 22 and defining a bearing housing interior 72, a compressor housing 74 coupled with bearing housing 70 and defining a compressor housing interior 76, a shaft 78 rotatably coupled to turbine wheel 68 and disposed in bearing housing interior 72, and a compressor wheel 80 rotatably coupled to shaft 78 and disposed in compressor housing interior 76.

[0027] The invention has been described in an illustrative manner, and it is to be understood that the terminology used is intended to be in the nature of words of description rather than of limitation. Many modifications and variations of the invention are possible in light of the above teachings, and the invention may be practiced otherwise than as specifically described.

Claims

1. 1. A turbine housing of a turbocharger for receiving exhaust gases from an internal combustion engine of a vehicle and delivering compressed air to the internal combustion engine, the turbine housing comprising: a turbine inlet wall configured to be in fluid communication with the internal combustion engine and defining an inlet passage for receiving exhaust gases from the internal combustion engine; an exducer shroud wall disposed downstream of and in flow communication with the inlet passage defining an exducer interior for receiving exhaust gases from the inlet passage; a turbine exit wall disposed downstream of and in flow communication with the exducer interior defining an exit passage for receiving exhaust gases from the exducer interior; a wastegate port wall disposed downstream of the inlet passage and in fluid communication therewith to define a wastegate channel for discharging exhaust gases from the inlet passage to the outlet passage by bypassing the exducer interior, the wastegate port wall disposed downstream of the wastegate channel to define a wastegate channel outlet for discharging exhaust gases into the outlet passage; a bushing wall defining a bushing boss coupled to the wastegate port wall and extending along a bushing axis, the bushing wall being spaced from the turbine inlet wall such that the wastegate port wall is disposed between the bushing wall and the turbine inlet wall; a valve seat disposed about the wastegate channel at the wastegate channel outlet, the wastegate port wall is disposed outside the exducer interior to thermally isolate the wastegate port wall and the bushing wall from the turbine inlet wall and to reduce relative displacement between the valve seat and the bushing shaft during operation of the turbocharger; a valve element engageable with the valve seat; the valve element is further defined as a valve body and a wastegate arm extending away from the valve body, the wastegate arm extending through the bushing boss and configured such that the valve body engages the valve seat when the valve element is in a first position that prevents exhaust gas from flowing from the inlet passage to the outlet passage by bypassing the exducer interior and the valve body disengages from the valve seat when the valve element is in a second position that allows exhaust gas to flow from the inlet passage to the outlet passage by bypassing the exducer interior; and the valve body and the wastegate arm are rigidly coupled to one another such that as the valve element moves between the first position and the second position, the valve body and the wastegate arm move simultaneously relative to one another.

2. The turbine housing of claim 1 , wherein the bushing wall is disposed outside the exducer interior in a configuration that thermally couples the bushing wall and the wastegate port wall to one another.

3. The turbine housing of claim 1 or 2, wherein the bushing wall is directly connected to the wastegate port wall.

4. 4. The turbine housing of claim 1, wherein the valve seat extends along a valve seat plane, the bushing axis and the valve seat plane define a distance therebetween, and the distance is less than or equal to 30 millimeters.

5. A turbine housing according to any preceding claim, wherein the bushing wall is directly connected to the wastegate port wall.

6. A turbine housing according to any one of claims 1 to 5, wherein the valve seat is disposed in the outlet passage.

7. The turbine housing has a platform surface extending parallel to the valve seat, the platform surface comprising: is flush with said valve seat; or A turbine housing according to any preceding claim, defining a recess, the valve seat being located within the recess.

8. A turbocharger including the turbine housing according to any one of claims 1 to 7, a wastegate assembly for controlling the flow of exhaust gases through the wastegate channel, comprising: a valve element engageable with the valve seat, the valve element being movable between a first position that prevents exhaust gas from flowing from the inlet passage to the outlet passage by bypassing the exducer interior and a second position that allows exhaust gas to flow from the inlet passage to the outlet passage by bypassing the exducer interior.

9. 9. The turbocharger of claim 8, further comprising a turbine wheel disposed in the exducer interior, a bearing housing coupled to the turbine housing and defining a bearing housing interior, a compressor housing coupled to the bearing housing and defining a compressor housing interior, a shaft rotatably coupled to the turbine wheel and disposed in the bearing housing interior, and a compressor wheel rotatably coupled to the shaft and disposed in the compressor housing interior.

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