WO2016057262A1

WO2016057262A1 - Variable turbine geometry turbocharger with a fixed vane flow control device

Info

Publication number: WO2016057262A1
Application number: PCT/US2015/052781
Authority: WO
Inventors: Shashikanth RAGHAVENDRA
Original assignee: Borgwarner Inc.
Priority date: 2014-10-08
Filing date: 2015-09-29
Publication date: 2016-04-14
Also published as: DE112015004613T5

Abstract

A variable turbine geometry turbine (20) includes a flow control device (100). The device (100) includes vanes (114) that are fixed to the turbine housing (22) and protrude into the throat (34) between the turbine volute (26) and turbine wheel (30). The device (100) also includes a hollow, cylindrical flow control member (152) having a sidewall (160) that is concentric with the exhaust gas outlet (28) and radially-extending sidewall openings (162) formed in the sidewall (160). The sidewall (160) is disposed in the central opening (112) such that the vanes (114) and the sidewall openings (162) reside in a common plane, and the flow control member (152) is configured to rotate whereby the sidewall openings (162) rotate relative to the vanes (114) so as control the amount of fluid flow through the throat (34).

Description

VARIABLE TURBINE GEOMETRY TURBOCHARGER WITH A FIXED VANE

FLOW CONTROL DEVICE

CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority to and all the benefits of U.S. Provisional Application

No. 62/061,431, filed on October 8, 2014, and entitled "Variable Turbine Geometry Turbocharger with a Fixed Vane Flow Control Device," which is incorporated herein by reference. BACKGROUND

Field of the Disclosure

This disclosure relates to an exhaust gas flow control device for a Variable Turbine Geometry (VTG) turbocharger including flow controlling vanes that are fixed relative to the turbine housing.

Description of Related Art

In exhaust gas turbocharging of vehicle engines, some of the exhaust gas energy, which would normally be wasted, is used to drive a turbine. The turbine includes a turbine wheel that is mounted on a shaft and is rotatably driven by exhaust gas flow. The turbocharger returns some of this normally wasted exhaust gas energy back into the engine, contributing to the efficiency of an engine and fuel consumption. A compressor, which is driven by the turbine, draws in filtered ambient air, compresses the air, and then supplies the compressed air to the engine. The compressor includes a compressor wheel that is mounted on the same shaft so that rotation of the turbine wheel causes rotation of the compressor wheel. Advantages of turbocharging include increased power output, lower fuel consumption, and reduced pollutant emissions. The turbocharging of engines is no longer primarily seen from a high-power performance perspective, but is rather viewed as a means of reducing fuel consumption and environmental pollution by reducing carbon dioxide (CO2) emissions. In turbocharged engines, combustion air is pre-compressed before being supplied to the engine. The engine aspirates the same volume of air- fuel mixture as a naturally aspirated engine, but due to the higher pressure, thus higher density, more air and fuel mass is supplied into a combustion chamber in a controlled manner. Consequently, more fuel can be burned, so that the power output of the engine increases relative to the speed and swept volume.

A turbocharger provides an ideal boost in only a limited range of conditions. Thus, a larger turbine for a given engine provides good boost at high speeds, but does not do well at low speeds because it suffers turbo lag and is thus unable to provide boost when needed. A small turbine provides good boost at low speeds, but can choke the engine at high speeds. In some turbochargers, the turbocharger with a variable turbine geometry (VTG) include movable vanes in the turbine housing in order to provide a boost over a wider range of conditions. At low speeds, when boost is needed quickly, the vanes can be closed creating a narrower passage for the flow of exhaust gas. The narrow passage accelerates the exhaust gas towards the turbine wheel blades allowing the turbocharger to provide a boost of power to the engine when needed. On the other hand when the engine is running at high speed and the pressure of the exhaust gas is high, the vanes may be opened and the turbocharger provides the appropriate amount of boost to the engine for the associated speed. By allowing the vanes to open and close, the turbocharger is permitted to operate under a wide variety of driving conditions as power is demanded by the engine. However, some moveable vane VTG turbochargers incorporate a large number of small parts, many of which are welded together using precision welds, increasing manufacturing costs. Due to the large number of moving parts to be assembled, the cost of manufacturing is further increased. Moreover, once installed and in operation, the VTG turbines operate in a very high temperature environment which can cause distortion of the VTG assembly. In some cases, the thermal distortion of the VTG assembly is sufficient to cause lock up of the assembly.

SUMMARY

A fixed-vane flow control device is used to provide a VTG turbocharger and control exhaust gas flow through a turbocharger turbine. The fixed-vane flow control device is disposed within a turbine housing, and includes a vane assembly that is fixed to the turbine housing and an adjustment ring assembly that is supported on, and rotatable relative to, the vane assembly. The vane assembly includes fixed vanes that protrude into a radially-extending throat that extends between the volute and the turbine wheel. The adjustment ring assembly includes a cylindrical flow control member having a series of optimized radial openings to control the amount of gas flow through the vane assembly. The flow control member is arranged within a central opening of the vane assembly so that the radial openings are radially aligned with the vanes. The radial openings are aligned with the VTG area of the turbine housing and rotate within the fixed vane assembly. By rotation of the flow control member relative to the vane assembly, the position of the radial openings relative to the vanes can be controlled, and thus the amount of exhaust gas flow through the VTG turbine housing can also be controlled. The fixed vane flow control device allows exhaust gas flow through the turbine to be throttled which in turn increases or decreases the turbine wheel speed, thus allowing boost control within the turbocharger. In particular, the fixed vane flow control device allows a turbine flow cross-section leading to the turbine wheel to be varied in accordance with engine operating points. This allows the entire exhaust gas energy to be utilized and the turbine flow cross-section to be set optimally for each operating point. As a result, the efficiency of the turbocharger and hence that of the engine can be improved, while employing fewer welded and rotating parts relative to some conventional movable vane VTG turbochargers.

BRIEF DESCRIPTION OF THE DRAWINGS Advantages of the present disclosure will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings wherein:

Fig. 1 is a schematic illustration of an engine system including an exhaust gas turbocharger; Fig. 2 is a perspective view of the turbine section of the turbocharger of Fig. 1 including a fixed-vane flow control device;

Fig. 3 is an exploded perspective view of the vane assembly of the fixed-vane flow control device;

Fig. 4 is a perspective view of the vane assembly of the fixed-vane flow control device; Fig. 5 is an exploded perspective view of the adjustment ring assembly of the fixed-vane flow control device;

Fig. 6 is a perspective view of the adjustment ring assembly of the fixed-vane flow control device;

Fig. 7 is a sectioned perspective view of the turbine section including the fixed-vane flow control device; Fig. 8 is a side cross-sectional view of the turbine section including the fixed-vane flow control device;

Fig. 9 is a perspective view of the fixed-vane flow control device;

Fig. 10 is an enlarged view of a portion of the fixed- vane flow control device of Fig. 9 illustrating the device in an open position;

Fig. 11 is an enlarged view of a portion of the fixed-vane flow control device of Fig. 9 illustrating the device in a partially closed position; and

Fig. 12 is a perspective view of the turbine section including the fixed- vane flow control device and a portion of the linkage used to connect the device to an actuator;

DETAILED DESCRIPTION

As shown in Fig. 1, an exhaust gas turbocharger 1 including a turbine section 20, a compressor section 10, and a center bearing housing 8 disposed therebetween and connecting the compressor section 10 to the turbine section 20. The turbine section 20 includes a turbine housing 22 and a turbine volute 26 formed therein. The turbine section further includes a turbine wheel 30 disposed within the turbine housing 22. The turbine wheel 30 is in fluid communication with a turbine inlet 24 and an exhaust gas outlet 28. The compressor section 10 includes a compressor housing 12 and a compressor volute 19 formed therein. The compressor section further includes a compressor wheel 14 disposed within the compressor housing 12. The compressor wheel 14 is in fluid communication with a compressor inlet 16 and compressor outlet 18. The turbine wheel 30 is connected to the compressor wheel 14 via a shaft 2. The shaft 2 is supported for rotation about a rotational axis R within the bearing housing 8 via bearings (not shown).

In use, the turbocharger 1 uses exhaust flow from an exhaust manifold 5 of an engine 3 to drive the turbine wheel 30. Exhaust flow enters the turbine inlet 24, travels through the turbine volute 26 and is projected over the turbine wheel 30. Once the exhaust gas has passed through the turbine wheel 30 and the turbine wheel 30 has extracted energy from the exhaust gas, the spent exhaust gas exits the turbine housing 22 through the exhaust gas outlet 28 and is ducted to the vehicle downpipe and usually to after-treatment devices such as catalytic converters, particulate traps, and NO_x traps (not shown). The energy extracted by the turbine wheel 30 is translated to a rotational motion that is used to drive a compressor wheel 14. As the compressor wheel 14 rotates, it increases the air mass flow rate, airflow density and air pressure delivered to cylinders 6 of the engine 3 via an outflow from the compressor outlet 18 of the compressor section 10, which is connected to the air intake manifold 4 o the engine 3.

Referring to Fig. 2, a fixed- vane flow control device 100 is used to control exhaust gas flow through the turbocharger turbine section 20. The fixed- vane flow control device 100 is disposed within the turbine housing 22, and includes a vane assembly 101 that is fixed to the turbine housing 22 and an adjustment ring assembly 150 that is supported on, and rotatable relative to, the vane assembly 101. By controlling the rotational orientation of the adjustment ring assembly 150 relative to the vane assembly 101, the amount of exhaust gas flow directed from the turbine volute 26 to the turbine wheel 30 can be controlled, permitting control of the boost provided by the turbocharger 1.

Referring to Fig. 3, the vane assembly 101 includes a vane ring 102, a retainer ring 132, and bolts 103 used to rigidly secure the vane ring 102, together with the retainer ring 132, to the turbine housing 22, as discussed further below. The vane ring 102 is an annular plate that includes a bearing housing-facing side 104, and a turbine housing-facing side 106. The vane ring 102 includes an inner edge 110 that defines a vane ring central opening 112, and a radially outward-facing outer edge 108. The vane ring 102 also includes vanes 114 disposed on the turbine housing-facing side 106. The vanes 114 are formed integrally with the vane ring 102 and protrude in a direction normal to the turbine housing-facing side 106. The vanes 114 are three-sided such that each vane 114 includes a base 122 that coincides with a portion of the inner edge 110, a long side 118 that extends between one end 125 of the base 122 and the radially outward-facing outer edge 108 of the vane ring 102, and a short side 120 that extends between an opposed end 126 of the base 122 and the radially outward-facing outer edge 108 of the vane ring 102. The long side 118 and the short side 120 intersect at the radially outward-facing outer edge 108 so as to form an apex 124 of the vane 114. In addition, the long side 118 and the short side 120 are curved so that each vane 114 is convex toward the radially outward-facing outer edge 108 and concave toward the inner edge 110 and central opening 112.

Vanes 114, detailed in Fig. 3 for example as a first vane 114a and a second vane 114b are equidistantly spaced about the vane ring central opening 112. Each of the fist vane 114a and the second vane 114b includes, a first base 122a and a second base 122b. The first base 122a coincides with a portion of the inner edge 110 and extends between a long side 118a and a short side 120a at a first end 125 a and a second end 126a. Similarly, the second base 122b coincides with a portion of the inner edge 110 and extends between a long side 118b and a short side 120b at a first end 125b and a second end 126b. An inner gap 121a exists between the first end 125 a of the first base 122a of the first vane 114a and the second end 126b of the second base 122b of the adjacent second vane 114b. Additionally, an outer gap 121b exists between an apex 124a of the one first vane 114a and an apex 124b of the adjacent second vane 114b. Due to the shape of the first and second vanes 114a,b, the length of the outer gap 121b is larger than the length of the inner gap 121a.

In addition, the vane ring 102 includes a first set of three through holes 116 that are equidistantly spaced about a circumference of the vane ring 102, and extend between the bearing housing-facing side 104 and the turbine housing-facing side 106. Each through hole 116 passes through a vane 114, and the first set of through holes 116 are shaped and dimensioned to receive one of the bolts 103 therein.

The retainer ring 132 is an annular plate that includes a bearing housing-facing side 134, and a turbine housing-facing side 136. The retainer ring 132 includes an inner edge 140 that defines a retainer ring central opening 142, and a radially outward-facing outer edge 138. The diameter of the inner edge 140 of the retainer ring 132 is the same as the diameter of the vane ring inner edge 110, and the diameter of the retainer ring outer edge 138 is the same as the diameter of the vane ring radially outward- facing outer edge 108. However, the thickness of the retainer ring 132 is greater than the thickness of the vane ring 102, where thickness refers to the distance between the bearing housing-facing side and the turbine housing-facing side. For example, the retainer ring 132 may be 3 to 6 times thicker than the vane ring 102. In addition, the retainer ring 132 includes a second set of three through holes 144 that are equidistantly spaced about a circumference of the retainer ring 132, and extend between the bearing housing- facing side 134 and the turbine housing-facing side 136. The through holes 144 are shaped and dimensioned to receive one of the bolts 103 therein.

Referring to Fig. 4, to form the vane assembly 101, the vane ring 102 is stacked with the retainer ring 132 such that the bearing housing-facing side 104 of the vane ring 102 abuts the turbine housing-facing side 136 of the retainer ring 132, and the respective central openings 112, 142 are aligned. In addition, the first and second set of through holes 116, 144, respectively, are also aligned such that the bolts 103 extend through both the first and second set of through holes 116, 144. Bolts 103 include bolt heads 103a that are positioned on the bearing housing-facing side 134 of the retainer ring 132 and aid with securing the vane ring 102 in the stacked position with respect to the retainer ring 132.

Referring again to Fig. 2 and now to Fig. 5, the adjustment ring assembly 150 includes an adjustment ring 180, and a flow control member 152 that is fixed to a turbine housing-facing side 186 of the adjustment ring 180.

The flow control member 152 includes a hollow, cylindrical sidewall 160 having an open first end 154, and an open second end 155 that is opposed to the open first end 154. The sidewall 160 defines a longitudinal axis 158 that extends between the open first and second ends 154, 155 of the sidewall 160. Radially-extending sidewall openings 162 are formed in the sidewall 160 at the open first end 154 of the sidewall 160 and provide a fluid flow passage between a radially outward- facing outer surface 156 and an inner surface 157 of the sidewall 160. The radially-extending sidewall openings 162 are equidistantly spaced about a circumference of the sidewall 160, whereby lands 163 are provided between adjacent radially- extending sidewall openings 162. The radially-extending sidewall openings 162 are defined by surfaces (162a-d), have a rectangular profile, and are elongated in the circumferential direction. Moreover, two of the surfaces (162a, 162b) which help to define the radially-extending sidewall openings 162, are formed at a predetermined angle relative to the outer and inner surfaces 156, 157. The predetermined angle corresponds to a desired angle of entry of fluid toward the turbine wheel, and, for example, is set to maximize the driving effect of exhaust gas flowing onto the turbine wheel 30. The radially-extending sidewall openings 162 have a circumferential dimension that corresponds to the length of the inner gap 121a between the bases 122 of adjacent vanes 114, and an axial dimension that corresponds to an axial dimension of the vanes 114.

The open second end 155 of the sidewall 160 is formed having a radially-outward protruding flange 164. The radially-outward protruding flange 164 surrounds the open second end 155 and is used to secure the flow control member 152 to the turbine housing facing side 186 of the adjustment ring 180 in a manner such that the sidewall longitudinal axis 158 extends in a direction normal to the turbine housing facing side 186 of the adjustment ring 180. The radially- outward protruding flange 164 includes three through holes 166 that are equidistantly spaced about a circumference of the radially-outward protruding flange 164, and extend between a bearing housing-facing side 168 and a turbine housing-facing side 167 of the radially-outward protruding flange 164. The through holes 166 are shaped and dimensioned to receive a post 195 therein. The adjustment ring 180 is an annular plate that includes a bearing housing-facing side 184, and the turbine housing-facing side 186. The adjustment ring 180 includes an inner edge 190 that defines an adjustment ring central opening 192, and a circular, radially outward- facing outer edge 188. The diameter of the adjustment ring inner edge 190 is the slightly larger than the diameter of the flow control member inner surface 157, and the diameter of the adjustment ring outer edge 188 is greater than the diameter of the radially-outward protruding flange 164 of the flow control member 152. The adjustment ring 180 includes tabs 194 that protrude radially outward from the outer edge 188. In the illustrated embodiment, three equidistantly spaced tabs 194 are formed along the outer edge 188. When assembled with the turbine housing 22, the turbine housing-facing side 186 of the tabs 194 abuts a bearing housing-facing shoulder 22a of the turbine housing 22, whereby the axial position of the adjustment ring 180 relative to the turbine housing is maintained. In addition, the adjustment ring 180 is connected to an actuator (not shown) via a block 197 connected to one of the tabs 194 via a pivot pin 198.

The adjustment ring 180 includes three through holes 196 that are equidistantly spaced about a circumference of the adjustment ring 180, and extend between the bearing housing- facing side 184 and the turbine housing-facing side 186. The through holes 196 are shaped and dimensioned to receive the post 195 therein.

Referring to Fig. 6, the flow control member 152 is assembled with the adjustment ring 180 to form the adjustment ring assembly 150 such that the bearing housing-facing side 168 of the flange radially-outward protruding 164 abuts the turbine housing-facing side 186 of the adjustment ring 180 and the adjustment ring central opening 192 is centered on the sidewall longitudinal axis 158. The respective through holes 166, 196 of the radially-outward protruding flange 164 and adjustment ring 180 are axially aligned, and the post 195 is disposed in and extends through each axially-aligned through hole 166, 196 so that the flow control member 152 will rotate in unison with the adjustment ring 180.

Referring to Fig. 7 and Fig. 8, the vane assembly 101, including the vane ring 102 and the retainer ring 132 together in the stacked arrangement, are secured to the turbine housing 22 via the bolts 103. In particular, bolts 103 extend through the respective first and second set of through holes 116, 144 and are received in a threaded bolt hole 32 formed in the turbine housing 22. The bolt hole 32 is axially located on an outboard side of the radially-extending throat 34 that extends between the turbine volute 26 and the turbine wheel 30 (removed here for simplicity). The bolt hole 32 is radially located between the turbine volute 26 and the exhaust gas outlet 28. Since the bolt 103 passes through the vane 114 rather than between adjacent vanes 114, the bolt 103 does not disrupt exhaust gas flow through the fixed- vane flow control device 100. As detailed earlier, the bolt 103 is arranged so that the head 103a of the bolt 103 resides on the bearing housing-facing side 134 of the retainer ring 132. In this position, the bolt head 103a serves as a spacer that maintains a desired axial spacing between the vane assembly 101 and the adjustment ring assembly 150, as discussed further below.

When the vane assembly 101 is secured to the turbine housing 22, the retainer ring 132 is received within a turbine housing bore 22b. In particular, the radially outward-facing outer edge 138 of the retainer ring 132 faces a radially inward-facing surface 22d of the turbine housing bore 22b, and the retainer ring central opening 142 is centered on the rotational axis R of the shaft 2. In this configuration, the vanes 114 protrude into the throat 34 and abut a bearing housing-facing wall 22c of the turbine housing 22. The bearing housing-facing wall 22c defines a portion of the throat 34.

The adjustment ring assembly 150 is disposed in the turbine housing 22 with the sidewall 160 of the flow control member 152 extending through the central openings 112, 142 of the vane ring 102 and retainer ring 132 such that the radially-outward protruding flange 164 of the flow control member 152 abuts the heads 103a of the bolts 103. In this configuration, the sidewall outer surface 156 abuts the inner edge 140 of the retainer ring 132, and the radially-extending sidewall openings 162 are positioned in the throat 34. In particular, the radially-extending sidewall openings 162 and the vanes 114 reside in a common plane P that is transverse to the rotational axis and passes through the throat 34.

Although the vane assembly 101 is fixed to the turbine housing 22, the adjustment ring assembly 150 is rotatable about the longitudinal axis 158 of the sidewall 160 of the adjustment ring assembly 150, relative to the vane assembly 101. The longitudinal axis 158 of the sidewall 160 of the adjustment ring assembly 150 is the same as rotational axis R of the shaft 2 of the turbocharger 1. As such, the adjustment ring assembly 150 radially locates on the vane ring inner edge 110, and the vane ring inner edge 110 generally provides a bearing surface for the adjustment ring assembly 150 and the sidewall 160 in particular.

Referring to Figs. 9-11, the fixed- vane flow control device 100 is used to control exhaust gas flow through the turbine section 20 of the turbocharger 1 according to the following parameters: a) the adjustment ring assembly 150 including the flow control member 152 is rotatable about the longitudinal axis 158 relative to the vane ring 102 in a direction indicated by the arrow in Fig. 9, and thus also the turbine housing 22; b) the adjustment ring assembly 150 including the flow control member 152 rotates a direction indicated by the arrow in Fig. 9 between a first rotational orientation and a second rotational orientation, as well as to intermediate rotational orientations between the first rotational orientation and the second rotational orientation; c) in the first rotational orientation, the radially-extending sidewall openings 162 are radially aligned with the inner gap 121a between adjacent vanes 114, and the lands 163 are radially aligned with a base 122 of a vane 114 (Fig. 10); d) in this position, the inner gap 121a is not obstructed, and exhaust gas flows between the vanes 114 toward the turbine wheel a maximal amount; e) in the second rotational orientation, each of the radially- extending sidewall openings 162 is at least partially obstructed by a corresponding vane 114, and the lands 163 at least partially obstruct the inner gap 121a (Fig. 11); and f) as a result, exhaust gas flow through the turbine housing 22 is reduced relative to the flow of the first position (e.g., exhaust gas flow is less than maximal). In some embodiments, the second rotational orientation may correspond to a configuration in which the inner gap 121a is fully obstructed by the lands 163, whereby exhaust gas is prevented from flowing through the turbine housing 22. In other embodiments, at least some exhaust gas flow is permitted through the turbine housing 22 regardless of the relative rotational orientations of the adjustment ring assembly 150 and the vane assembly 101.

Rotation of the adjustment ring assembly 150 relative to the turbine housing 22 is accomplished via rotation of the adjustment ring 180. As previously discussed, the adjustment ring 180 is connected to an actuator (not shown) via the pivotable block 197 connected to one of the tabs 194. In some embodiments, the pivotable block 197 is connected to the actuator (not shown) using a conventional VTG linkage assembly, including using an actuation pivot shaft 199 to engage the pivotable block 197.

The fixed- vane flow control device 100 allows exhaust gas flow through the turbine 1 to be throttled to increase or decrease the turbine wheel speed, thus allowing boost control within the turbocharger. In particular, the fixed- vane flow control device 100 allows a turbine flow cross-section leading to the turbine wheel to be varied in accordance with engine operating points. This allows the entire exhaust gas energy to be utilized and the turbine flow cross-section to be set optimally for each operating point. As a result, the efficiency of the turbocharger 1 and hence that of the engine can be improved.

In the illustrated embodiment, the vanes 114 have a three-sided, curved profile as described above, but the vanes 114 are not limited to this shape. In particular, the vanes 114 can be provided in any shape that provides a desired exhaust gas flow profile and/or direction. For example, the vanes 114 may have a three-sided straight profile. In another example, the vanes 114 may be two-sided and have an airfoil-shaped profile.

In the illustrated embodiment, the vane ring 102 includes nine vanes 114. However, it is understood that the number of vanes 114 is not limited to nine, and can be increased or decreased depending on the requirements of the specific application. The number of radially-extending sidewall openings 162 corresponds to the number of vanes 114.

In the illustrated embodiment, three bolts 103 are used to secure the vane assembly 101 to the turbine housing 22. However, it is understood that a greater or fewer number of bolts 103 can be used. The use of at least three bolts 103 is considered to work well in reducing and/or minimizing thermal distortion of the assembly.

In the illustrated embodiment, the flow control member 152 includes radially-extending sidewall openings 162 having a rectangular shape. However, the radially-extending sidewall openings 162 are not limited to a rectangular shape, and the shape of the radially-extending sidewall openings 162 can be any shape that meets the requirements of the specific application. For example, the sidewall opening shape may square or other polygonal shape, circular, oval or other curved shape, or irregularly shaped such as a cat-eye shape.

Moreover, the size of the radially-extending sidewall openings 162 may be changed (e.g., made longer or shorter than the length of the inner gap 121a) to optimize function of the fixed- vane flow control device 100, and/or address the requirements of a specific application. An exemplary flow control device 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 limitation. Many modifications and variations of the device described herein are possible in light of the above teachings. It is, therefore, to be understood that within the scope of the appended claims, the inventive concepts and devices may be practiced other than as specifically enumerated within the description.

Claims

CLAIMS What is claimed is:

1. An exhaust gas turbocharger (1) comprising a turbine (20), the turbine (20) including

a turbine housing (22) including an exhaust gas outlet (28) that extends in parallel to a rotational axis (R) of a turbine wheel (30) disposed in the turbine housing (22), and a volute (26) including a throat (34) that directs exhaust gas flow radially toward the turbine wheel (30), a vane ring (102) fixed to the turbine housing (22), the vane ring (102) including

a turbine housing-facing side (106),

fixed vanes (114) protruding from the turbine housing-facing side (106) and extending into the throat (34), and

a central opening (112);

a cylindrical flow control member (152) including a sidewall (160) that is concentric with the exhaust gas outlet (28), and radially-extending sidewall openings (162) formed in the sidewall (160), wherein

the sidewall (160) is disposed in the central opening (112) such that the vanes (114) and the radially-extending sidewall openings (162) reside in a common plane (P) that is transverse to the rotational axis (R), and

the flow control member (152) is configured to rotate about the rotational axis (R) relative to the vane ring (102) whereby the radially-extending sidewall openings (162) rotate relative to the vanes (114) so as to control the amount of fluid flow through the turbine housing (22).

2. The exhaust gas turbocharger (1) of claim 1, wherein

the flow control member (152) rotates between a first rotational orientation in which at least one radially-extending sidewall opening (162) is radially aligned with a gap (121a) between adjacent vanes (114) and exhaust gas flow through the turbine housing (22) is maximal, and a second rotational orientation in which the at least one radially-extending sidewall opening (162) is at least partially obstructed by at least one of the vanes (114) and exhaust gas flow through the turbine housing (22) is less than maximal.

3. The exhaust gas turbocharger (1) of claim 1, wherein the turbocharger (1) includes an adjustment ring assembly (150) that comprises

an adjustment ring (180), and the flow control member (152) that is fixed to a turbine housing-facing side (186) of the adjustment ring (180).

4. The exhaust gas turbocharger (1) of claim 3, wherein the adjustment ring (180) is an annular plate having a circular, radially outward-facing edge (188), the adjustment ring (180) including tabs (194) that protrude radially outward from the edge (188).

5. The exhaust gas turbocharger (1) of claim 1, wherein the vane ring (102) is secured to the turbine housing (22) using bolts (103) that extend through the vanes (114).

6. The exhaust gas turbocharger (1) of claim 1, wherein the vane ring (102) is secured to the turbine housing (22) using at least three bolts (103).

7. The exhaust gas turbocharger (1) of claim 1, wherein the turbocharger (1) includes a vane assembly (101), the vane assembly (101) including the vane ring (102), and

a retainer ring (132) that is secured to the vane ring (102) on a bearing housing-facing side (104) of the vane ring (102) that is opposed to the vanes (114).

8. The exhaust gas turbocharger (1) of claim 1, wherein each vane (114) comprises a base (122) that coincides with a portion of the central opening (112), a long side (118) that extends between one end (125) of the base (122) and an outer edge (108) of the vane ring (102), and a short side (120) that extends between another end (126) of the base (122) and the outer edge (108) of the vane ring (102), the long side (118) and the short side (120) intersecting at the outer edge (108) to form an apex (124) of the vane (114).

9. The exhaust gas turbocharger (1) of claim 8, wherein the long side (118) and the short side (120) are curved wherein the vane (114) is convex toward the outer edge (108) and concave toward the central opening (112).

10. The exhaust gas turbocharger (1) of claim 1, wherein

the flow control member (152) is secured to an adjustment ring (180) in a manner such that the side wall (160) extends perpendicularly relative to a turbine housing-facing side (186) of the adjustment ring (180), the vane ring (102) is secured to a retainer ring (132), and the retainer ring (132) is secured to the turbine housing (22) via bolts (103) that extend through the vane ring (102) and the retainer ring (132) such that a bolt head (103a) is disposed on a bearing housing-facing side (134) of the retainer ring (132), and

the bolt head (103a) maintains a desired axial spacing between the retainer ring (132) and the adjustment ring (180).

11. The exhaust gas turbocharger (1) of claim 1, wherein the flow control member (152) has a first end (154), and a second end (155) opposed to the first end (154), the second end (155) including a radially-outward protruding flange (164) used to secure the flow control member (152) to an adjustment ring (180).

12. The exhaust gas turbocharger (1) of claim 1, wherein the radially-extending sidewall openings (162) are defined by surfaces (162a-d) and are elongated in a circumferential direction with respect to the sidewall (160).

13. The exhaust gas turbocharger (1) of claim 1, wherein surfaces (162a, 162b) which define the radially-extending sidewall openings (162) are formed at a predetermined angle corresponding to a desired angle of entry of fluid flow toward the turbine wheel (30).

14. A variable turbine geometry turbine (20) comprising

a turbine housing (22) including an exhaust gas outlet (28) that extends in parallel to a rotational axis (R) of a turbine wheel (30) disposed in the turbine housing (22), and a volute (26) including a throat (34) that directs exhaust gas flow radially toward the turbine wheel (30), a flow control device (100) disposed in the turbine housing (22) including

vanes (114) that are fixed to the turbine housing (22) and protrude into the throat

(34), and

a hollow, cylindrical flow control member (152) including

a sidewall (160) that is concentric with the exhaust gas outlet (28), and radially-extending sidewall openings (162) formed in the sidewall (160), wherein

the sidewall (160) is disposed in the exhaust gas outlet (28) such that the vanes (114) and the radially-extending sidewall openings (162) reside in a common plane (P) that is transverse to the rotational axis (R), and the flow control member (152) is configured to rotate about the rotational axis (R) whereby the radially-extending sidewall openings (162) rotate relative to the vanes (114) so as control the amount of fluid flow through the throat (34).

15. The variable turbine geometry turbine (20) of claim 14, wherein

the flow control member (152) rotates between a first rotational orientation in which at least one radially-extending sidewall opening (162) is radially aligned with a gap (121a) between adjacent vanes (114) and exhaust gas flow through the turbine housing (22) is maximal, and a second rotational orientation in which the at least one radially-extending sidewall opening (162) is at least partially obstructed by a vane (114) and exhaust gas flow through the turbine housing (22) is less than maximal.