Turbocharger

Patent metadata

Field	Value
Publication number	US-8961151-B2
Application number	US-201213437272-A
Country	US
Kind code	B2
Filing date	Apr 2, 2012
Priority date	Apr 2, 2011
Publication date	Feb 24, 2015
Grant date	Feb 24, 2015

Abstract

A turbocharger shaft interconnects the compressor impeller and the turbine wheel and a bearing housing between the compressor and turbine houses a bearing assembly supporting the turbocharger shaft rotation. A shaft bore defined in at least one of the compressor, turbine or bearing housings receiving the shaft. A sealing arrangement for restricting leakage of lubricant along the shaft bore from the bearing housing to the compressor or turbine housing. The sealing arrangement comprises at least one sealing ring around the shaft in the shaft bore and a gas passage communicating with the shaft bore. A gas distribution circuit includes a valve movable between a first position in which gas passage is in communication with a gas supply path for supplying gas to the shaft bore and a second position in which the gas passage is in communication with a vent path for venting gas from the shaft bore.

First claim

The invention claimed is:

1. A turbocharger comprising:
a compressor for delivering pressurised air to an intake of an internal combustion engine, the compressor comprising a compressor housing and a compressor impeller disposed in the compressor housing:
a turbine bar receipt of exhaust gas from the engine, the turbine comprising a turbine housing and a turbine wheel disposed in the turbine housing;
a turbocharger shaft interconnecting the compressor impeller and the turbine wheel;
a bearing housing disposed between the compressor and turbine for housing a bearing assembly to support the turbocharger shaft in rotation;
a shaft bore defined in at least one of the compressor, turbine or bearing housings for receipt of the shaft;
a sealing arrangement for restricting leakage of lubricant along the shaft bore from the bearing housing to the compressor or turbine housing, the sealing arrangement comprising at least one sealing member disposed around the shaft in the shaft bore and a gas passage communicating with the shaft bore; and
a valve movable between a first position in which the gas passage is in communication with a gas supply path for supplying gas to the shaft bore and a second position in which the gas passage is in communication with a vent path for venting gas from the shaft bore;
wherein the valve is arranged such that it is movable in response to the prevailing pressure within the compressor or turbine housing at a location in fluid communication with the sealing arrangement.

2. A turbocharger according to claim 1 , wherein the at least one sealing member is a substantially annular member supported on a substantially annular surface defined by the shaft bore.

3. A turbocharger according to claim 2 , wherein at least one sealing member extends inwards into at least one groove defined on an outer surface of the shaft or of a component mounted on the shaft.

4. A turbocharger according to claim 1 , wherein there is a pair of sealing members disposed in the shaft bore such that they are axially separated and define a space between them, and wherein the gas passage is in communication with the space.

5. A turbocharger according to claim 1 , wherein the gas supply path is in communication with an outlet of the compressor.

6. A turbocharger according to claim 1 , wherein the gas supply is in communication with the interior of the turbine housing.

7. A turbocharger according to claim 1 , wherein the gas supply path has a firm part in communication with an outlet of the compressor and a second part in communication with the interior of the turbine housing and there is provided a valve between the first and second portions for selectively opening or closing the first and second part.

8. A turbocharger according to claim 1 , wherein the gas vent path is in communication with an inlet of the compressor inlet and/or atmosphere.

9. A turbocharger according to claim 1 , wherein the gas passage is defined in a back plate of the compressor housing.

10. A turbocharger according to claim 1 , wherein the valve has a control input for receiving a control signal that effects movement of the valve between the first and second positions.

11. A turbocharger according to claim 10 , wherein the control input is in communication with the interior of the compressor or turbine housing in a location in fluid communication with the sealing arrangement.

12. A turbocharger according to claim 10 , wherein the valve comprises a valve member that is movable dependent on the control signal.

13. A turbocharger according to claim 10 , 11 or 12 , wherein the sealing arrangement is provided at or proximate to the compressor and the control input is in communication with the interior of the compressor housing.

14. A method for operating a turbocharger which has a shaft bore defined in at least one of a compressor, turbine or bearing housings for receipt of turbocharger shaft, a sealing arrangement for restricting leakage of lubricant along the shaft bore from the bearing housing to the compressor or turbine housing, the sealing arrangement completing at least one sealing member disposed around the shaft in the shaft bore and a gas passage communicating with the shaft bore, the method comprising the steps of selectively moving the valve between a that position in which the gas passage is in communication with a gas supply path for supplying gas to the shaft bore and a second position in which the gas passage is in communication with a vent path for venting gas from the shaft bore wherein the valve is moved in response to the prevailing pressure within the compressor or turbine housing at a location in fluid communication with the sealing arrangement.

15. A method according to claim 14 , wherein the gas supply path is in communication with the interior of the turbine housing and/or an outlet of the compressor housing.

16. A method according to claim 15 , wherein the turbocharger is operatively connected to an internal combustion engine and the gas supply path is selectively placed in communication with the outlet of the compressor housing and/or an interior of the turbine housing depending on a mode of operation of the engine.

17. A method according to claim 16 , wherein the gas supply path is selectively placed in communication with the outlet of the compressor housing when the internal combustion engine is operated in engine-fired mode and/or is selectively placed m communication with the interior of the turbine housing when the engine is operated in engine braking mode.

18. A method for operating a turbocharger which has a shaft bore defined in at least one of a compressor, turbine or bearing housings for receipt of a turbocharger shaft, a sealing arrangement for restricting leakage of lubricant along the shaft bore from the bearing housing to the compressor or turbine housing, the sealing arrangement comprising at least one sealing member disposed around the shaft in the shaft bore and a gas passage communicating with the shaft bore, the method comprising the steps of selectively moving a valve between a first position in which the gas passage is in communication with a gas supply path for supplying as to the shaft bore and a second position in which the gas passage is in communication with a vent path for venting gas from the shaft bore, the gas supply path is in communication with the interior of the turbine housing and/or an outlet of the compressor housing, wherein the turbocharger is operatively connected to an internal combustion engine and the gas supply path is selectively placed in communication with the outlet of the compressor housing and/or an interior of the turbine housing depending on a mode of operation of the engine.

19. A method according to claim 18 wherein the gas supply path is selectively placed in communication with the outlet of the compressor housing when the internal combustion engine is operated in engine-fired mode and/or is selectively placed in communication with the interior of the turbine housing when the engine is operated in engine braking mode.

Assignees

• Patel Fahim Ismail
• Mcewen James Alexander
• Cummins Ltd

Inventors

• Patel Fahim Ismail
• Mcewen James Alexander

Classifications

• F02C6/12 Primary

  Turbochargers, i.e. plants for augmenting mechanical power output of internal-combustion piston engines by increase of charge pressure · CPC title

• F04D29/102

  especially adapted for elastic fluid pumps · CPC title

• F02B39/14

  Lubrication of pumps; Safety measures therefor · CPC title

• F01D11/003

  by packing rings; Mechanical seals · CPC title

• F01D11/06

  Control thereof · CPC title