Turbocharger Turbine Assembly

Patent metadata

Field	Value
Publication number	US-2016265388-A1
Application number	US-201514642133-A
Country	US
Kind code	A1
Filing date	Mar 9, 2015
Priority date	Mar 9, 2015
Publication date	Sep 15, 2016
Grant date	—

Abstract

A turbocharger including a turbine housing including a gas inlet passage and a turbine wheel arranged in the turbine housing. A bearing housing is connected to the turbine housing. A nozzle ring is disposed around the turbine wheel and a shroud is arranged in surrounding relation to at least a portion of the turbine wheel. The shroud is connected to the nozzle ring and the nozzle ring and shroud are connected to a heat shield. The heat shield is secured to the bearing housing by a plurality of cross key pins, each cross key pin being inserted in a radially extending first passage in the heat shield and a complementary radially extending second passage in the bearing housing. The first passages and second passages are symmetrically arranged in a circular pattern about a rotational axis of the turbine.

First claim

We claim:

1 . A turbocharger comprising:
a turbine housing including a gas inlet passage; a turbine wheel that has a plurality of blades and is arranged in the turbine housing; a bearing housing connected to the turbine housing; a shaft rotatably supported in the bearing housing and connected to the turbine wheel; a heat shield; a nozzle ring disposed around the turbine wheel and including a plurality of vanes with flow channels being defined between the vanes that are in fluid communication the gas inlet passage and with the turbine wheel; and a shroud arranged in surrounding relation to at least a portion of the turbine wheel, the shroud being connected to the nozzle ring, the nozzle ring and shroud are connected to the heat shield; wherein the heat shield is secured to the bearing housing by a plurality of cross key pins, each cross key pin being inserted in a radially extending first passage in the heat shield and a complementary radially extending second passage in the bearing housing, the first passages and second passages being symmetrically arranged in a circular pattern about a rotational axis of the turbine wheel such that the cross key pins force symmetrical thermal expansion of the heat shield, nozzle ring and shroud during operation of the turbocharger.

2 . The turbocharger of claim 1 wherein the shroud is integrally formed with the nozzle ring such that the plurality of vanes extend away from the shroud.

3 . The turbocharger of claim 1 wherein the shroud, the nozzle ring and the heat shield are made of the same material.

4 . The turbocharger of claim 1 wherein the flow channels defined by the vanes are configured to direct gas tangentially and radially inward toward an inner diameter of the turbine wheel and the shroud is configured to define a flow path in communication with the gas inlet passage and the flow channels, the flow path extending in a direction substantially parallel to a rotational axis of the turbine wheel.

5 . The turbocharger of claim 4 wherein the shroud includes a first leg that extends in a radial direction of the turbine wheel and a second leg that extends in the direction substantially parallel to the rotational axis of the turbine wheel.

6 . The turbocharger of claim 5 wherein the vanes extend from the first leg of the shroud.

7 . The turbocharger of claim 5 further including a first gas seal arranged between the second leg of the shroud and an inside wall of the turbine housing.

8 . The turbocharger of claim 7 further including a second gas seal arranged between the heat shield and the bearing housing.

9 . The turbocharger of claim 8 wherein the second seal comprises a plurality of knife edge seals that extend from a surface of the heat shield into engagement with the bearing housing.

10 . A method of providing symmetrical thermal expansion of components of a turbocharger including a turbine housing and a turbine wheel arranged in the turbine housing and connected to a shaft that is rotatably supported in a bearing housing, the method comprising:
providing a nozzle ring disposed around the turbine wheel and including a plurality of vanes with flow channels being defined between the vanes that are in fluid communication the gas inlet passage and with the turbine wheel; and connecting a shroud arranged in surrounding relation to at least a portion of the turbine wheel to the nozzle ring; connecting the shroud and the nozzle ring to a heat shield; connecting the heat shield to the bearing housing with a plurality of cross key pins, each cross key pin being inserted in a radially extending first passage in the heat shield and a complementary radially extending second passage in the bearing housing, the first passages and second passages being symmetrically arranged in a circular pattern about a rotational axis of the turbine wheel such that the cross key pins force symmetrical thermal expansion of the heat shield, nozzle ring and shroud during operation of the turbocharger.

11 . The method of claim 10 wherein the shroud is integrally formed with the nozzle ring such that the plurality of vanes extend away from the shroud.

12 . The method of claim 10 wherein the shroud, the nozzle ring and the heat shield are made of the same material.

13 . The method of claim 11 wherein the flow channels defined by the vanes are configured to direct gas tangentially and radially inward toward an inner diameter of the turbine wheel and the shroud is configured to define a flow path in communication with the gas inlet passage and the flow channels, the flow path extending in a direction substantially parallel to a rotational axis of the turbine wheel.

14 . The method of claim 13 wherein the shroud includes a first leg that extends in a radial direction of the turbine wheel and a second leg that extends in the direction substantially parallel to the rotational axis of the turbine wheel.

15 . The method of claim 14 further including providing a first gas seal arranged between the second leg of the shroud and an inside wall of the turbine housing.

16 . The method of claim 15 further including providing a second gas seal arranged between the heat shield and the bearing housing.

17 . An internal combustion engine having a plurality of combustion chambers formed in a cylinder block, an intake manifold disposed to provide air or a mixture of air with exhaust gas to the combustion chambers, and an exhaust manifold disposed to receive exhaust gas from the combustion chambers, the engine further comprising:
a turbine housing including a gas inlet passage; a turbine wheel that has a plurality of blades and is arranged in the turbine housing; a bearing housing connected to the turbine housing; a shaft rotatably supported in the bearing housing and connected to the turbine wheel; a heat shield; a nozzle ring disposed around the turbine wheel and including a plurality of vanes with flow channels being defined between the vanes that are in fluid communication the gas inlet passage and with the turbine wheel; and a shroud arranged in surrounding relation to at least a portion of the turbine wheel, the shroud being connected to the nozzle ring, the nozzle ring and shroud are connected to the heat shield; wherein the heat shield is secured to the bearing housing by a plurality of cross key pins, each cross key pin being inserted in a radially extending first passage in the heat shield and a complementary radially extending second passage in the bearing housing, the first passages and second passages being symmetrically arranged in a circular pattern about a rotational axis of the turbine wheel such that the cross key pins force symmetrical thermal expansion of the heat shield, nozzle ring and shroud during operation of the turbocharger.

18 . The engine of claim 17 wherein the shroud, the nozzle ring and the heat shield are made of the same material.

19 . The engine of claim 17 wherein the flow channels defined by the vanes are configured to direct gas tangentially and radially inward toward an inner diameter of the turbine wheel and the shroud is configured to define a flow path in communication with the gas inlet passage and the flow channels, the flow path extending in a direction substantially parallel to a rotational axis of the turbine wheel.

20 . The engine of claim 17 wherein the shroud is integrally formed with the nozzle ring such that the plurality of vanes extend away from the shroud.

Assignees

• Caterpillar Inc

Inventors

• Annati Richard E
• Frick Matthew J

Classifications

• F01D25/243

  Flange connections; Bolting arrangements (F01D25/265 takes precedence) · CPC title

• F05D2260/231

  Preventing heat transfer · CPC title

• F01D9/048

  for radial admission · CPC title

• F02B39/08

  Non-mechanical drives, e.g. fluid drives having variable gear ratio · CPC title

• F01D25/26 Primary

  Double casings; Measures against temperature strain in casings · CPC title