Simplified variable geometry turbocharger with variable flow volumes

Patent metadata

Field	Value
Publication number	US-8984879-B2
Application number	US-201013264456-A
Country	US
Kind code	B2
Filing date	Apr 19, 2010
Priority date	Apr 20, 2009
Publication date	Mar 24, 2015
Grant date	Mar 24, 2015

Abstract

A variable geometry turbocharger is simplified yet able to maintain pulse energy. In a first embodiment, a turbine housing is provided with a pivoting wall which pivots about a point near the entry to the turbine housing. By moving the wall about the pivot point, the effective volume of the turbine housing volute is varied, thus effectively reducing the volume of exhaust gas in the volute, allowing control of exhaust gas flowing to the turbine wheel. In the second embodiment of the invention, a rotating wedge segment within the volute is rotated from a first position to a second position, changing the effective volume of the volute and allowing control of exhaust gas flowing to the turbine wheel.

First claim

Now that the invention has been described, we claim:

1. A turbocharger for an internal combustion engine comprising:
a turbine housing ( 2 ) including an inlet at a turbine housing foot ( 51 ) for receiving exhaust gas;
a turbine wheel ( 70 ) rotatably mounted in said housing;
a volute for directing exhaust gases from said inlet onto said turbine wheel, said volute including a radially outer wall, said radially outer wall constituted by
a fixed radially outer wall segment of the turbine housing terminating in a tongue, and
a pivotable radially outer wall ( 33 ) having an upstream end pivotably mounted to the turbine housing ( 2 ) upstream of the tongue and a curved downstream end, said pivotable radially outer wall pivotable from a retracted position further from the turbine wheel to an extended position nearer the turbine wheel; and

a control device configured to control movement of the pivotable radially outer wall downstream end from said retracted position to the extended position,
wherein the pivotable radially outer wall includes a reinforcing rib that protrudes from a radially outward-facing side of the pivotable radially outer wall, is elongated in a direction corresponding to a direction of exhaust gas flow through the turbine housing, and together with the pivotable radially outer wall is movable relative to the fixed radially outer wall segment.

2. The turbocharger as in claim 1 , wherein the turbine wheel is solidly affixed to a shaft, wherein a compressor wheel ( 20 ) of a compressor is mounted to the other end of the shaft, wherein exhaust flow ( 100 ) from an engine exhaust manifold enters the turbine housing ( 2 ) via the turbine housing foot ( 51 ) to drive the turbine wheel ( 70 ) to provide rotational power to drive a compressor, whereby pressurized gas exits a compressor cover ( 10 ) through a compressor discharge ( 12 ) and is delivered to an intake of the engine,
wherein said pivotable wall ( 33 ) is contoured such that when the pivotable wall is moved from the retracted position to the extended position:
an upstream part of the pivotable radially outer wall ( 33 ) cooperates with the tongue to form a constriction for accelerating exhaust gas flow, and
the curved downstream end of the pivotable wall directs gas flow closer to the turbine wheel,
whereby the effective flow volume of the volute is reduced to enhance transient response of the engine.

3. The turbocharger as in claim 1 , including an actuator spring housing ( 38 ) housing a spring ( 18 ) exercising a spring force urging the pivotable radially outer wall ( 33 ) towards the extended pivot position, such that at low backpressure the pivotable radially outer wall is urged by said spring into the extended position, and at high backpressure the backpressure overcomes the spring force and urges the pivotable radially outer wall to pivot to the retracted position.

4. The turbocharger as in claim 3 , including at least one shim to increase spring seat pressure.

5. The turbocharger as in claim 1 , wherein said reinforcing rib extends perpendicularly from said pivotable radially outer wall.

6. The turbocharger as in claim 1 , wherein said control device is selected from the group consisting of a metal spring, hydraulic actuator, pneumatic actuator, or electric actuator.

7. The turbocharger as in claim 1 , wherein said pivotable radially outer wall ( 33 ) includes a divider wall ( 26 ) extending radially inward, perpendicularly from said pivotable radially outer wall.

8. The turbocharger as in claim 7 , wherein said divider wall ( 26 ) is a solid divider wall.

9. The turbocharger as in claim 7 , wherein said divider wall ( 26 ) is provided with openings.

10. A turbocharger for an internal combustion engine comprising:
a turbine housing ( 2 ) including an inlet at a turbine housing foot ( 51 ) for receiving exhaust gas;
a turbine wheel rotatably mounted in said housing;
a volute for directing exhaust gases from said inlet onto said turbine wheel, said volute including a radially outer wall, said radially outer wall constituted by
a fixed radially outer wall segment of the turbine housing terminating in a tongue, and
a flexible radially outer wall having an upstream end anchored to the turbine housing ( 2 ) upstream of the tongue and a curved downstream end, said flexible radially outer wall moveable from a retracted position further from the turbine wheel to an extended position nearer the turbine wheel; and

a control device configured to control movement of the flexible radially outer wall downstream end from said retracted position to the extended position,
wherein the flexible radially outer wall includes a reinforcing rib that protrudes from a radially outward-facing side of the flexible radially outer wall, is elongated in a direction corresponding to a direction of exhaust gas flow through the turbine housing, and together with the flexible radially outer wall is movable relative to the fixed radially outer wall segment.

11. A turbocharger for an internal combustion engine comprising:
a turbine housing ( 2 ) including an inlet at a turbine housing foot ( 51 ) for receiving exhaust gas, said turbine housing including a volute with a radially outer wall ( 74 ) having a constant radius;
a turbine wheel rotatably mounted in said housing;
a rotating curved wedge segment ( 72 ) defined by a radially outer wall flush with said turbine housing wall ( 74 ) of constant radius, and a radially inner wall of constantly decreasing radius in the downstream direction, said curved wedge segment thus having a tapered upstream end and a wide downstream end, said rotating curved wedge segment mounted for rotating between a lower effective flow volume position and a higher effective flow volume position;
a fixed curved wedge part ( 73 ) including a chamber for receiving the rotating curved wedge segment thick end when the rotating curved wedge segment ( 72 ) is rotated to a high effective flow volume position, and having an exterior defining a continuation of the rotating curved wedge segment when the rotating curved wedge segment is pivoted to the low effective flow volume position.

12. The turbocharger as in claim 11 , wherein said rotating curved wedge segment ( 72 ) is guided by sets of rolling elements ( 77 ) which run in tracks ( 76 ) in the turbine housing casting.

13. The turbocharger as in claim 11 , wherein said rotating wedge segment ( 72 ) is guided by the surface of the rotating wedge segment and tracks in the turbine housing casting.

14. The turbocharger as in claim 11 , comprising a control device configured to control movement of the rotating curved wedge segment ( 72 ), the control device selected from the group consisting of a metal spring, hydraulic actuator, pneumatic actuator, or electric actuator.

15. The turbocharger as in claim 11 , wherein said pivotable radially outer wall ( 33 ) includes a divider wall ( 26 ) extending radially inward, perpendicularly from said pivotable radially outer wall.

16. The turbocharger as in claim 15 , wherein said divider wall ( 26 ) is a solid divider wall.

17. The turbocharger as in claim 15 , wherein said divider wall ( 26 ) is provided with openings.

18. A method for controlling backpressure in a turbocharger for an internal combustion engine, the turbocharger comprising:
a turbine housing ( 2 ) including an inlet at a turbine housing foot ( 51 ) for receiving exhaust gas;
a turbine wheel rotatably mounted in said housing;
a volute for directing exhaust gases from said inlet onto said turbine wheel, said volute including

Assignees

• Watson John P
• Bernauer Tilman
• Henderson Kurtis E
• Grabowska David G
• Borgwarner Inc

Inventors

• Watson John P
• Bernauer Tilman
• Henderson Kurtis E
• Grabowska David G

Classifications

• F02B37/22 Primary

  by varying cross-section of exhaust passages or air passages {, e.g. by throttling turbine inlets or outlets or by varying effective number of guide conduits} (F02B37/24 takes precedence) · CPC title

• F02B37/025

  Multiple scrolls or multiple gas passages guiding the gas to the pump drive · CPC title

• F05D2220/40

  in turbochargers · CPC title

• F01D17/146

  by throttling the volute inlet of radial machines or engines · CPC title

• F05D2260/53

  using gears · CPC title