Turbocharger turbine containment structure

• US 9,650,913 B2
• Filed: 03/09/2015
• Issued: 05/16/2017
• Est. Priority Date: 03/09/2015
• Status: Expired due to Fees

• Current Assignee: Caterpillar Incorporated
• Original Assignee: Caterpillar Incorporated
• Inventors: Annati, Richard E., Powers, Gary W., McCormack, Jeffrey W., Frick, Matthew J.
• Primary Examiner(s): Trieu, Thai Ba
• Application Number:
  US14/642,033
• Publication Number:
  US 20160265382A1
• Time in Patent Office: 799 Days
• Field of Search: 60602, 415158-164, 4151821, 4151742, 417406-407
• CPC Class Codes: F01D 21/04 responsive to undesired position of rotor relative to stator or to breaking-off of a part of the rotor, e.g. indicating such position
• CPC Class Codes: F01D 25/08 Cooling of machines or engines in general F01P; Heating; Heat-insulation of blade-carrying members, of blades F01D5/00
• CPC Class Codes: F01D 25/162 Bearing supports
• CPC Class Codes: F01D 25/24 Casings modified for heating or cooling F01D25/14; Casing parts, e.g. diaphragms, casing fastenings casings for rotary machines or engines in general F16M ; special arrangements in stators dealing with breaking-off of part of rotor F01D21/045
• CPC Class Codes: F01D 5/02 Blade-carrying members, e.g. rotors rotors of non-bladed type F01D1/34; stators F01D9/00 ; selecting particular materials F01D5/28
• CPC Class Codes: F01D 5/12 Blades specially adapted for radial flow machines or engines F01D5/04; blade roots F01D5/30; rotors with blades adjustable in operation F01D7/00; stator blades F01D9/02
• CPC Class Codes: F01D 9/041 using blades F01D5/148 takes precedence
• CPC Class Codes: F02B 33/40 of non-positive-displacement type
• CPC Class Codes: F02B 37/00 Engines characterised by provision of pumps driven at least for part of the time by exhaust
• CPC Class Codes: F02B 37/24 by using pumps or turbines with adjustable guide vanes
• CPC Class Codes: F02B 39/00 Component parts, details, or accessories relating to, driven charging or scavenging pumps, not provided for in groups F02B33/00 - F02B37/00
• CPC Class Codes: F02M 35/10222 Exhaust gas recirculation [EGR]; Positive crankcase ventilation [PCV]; Additional air admission, lubricant or fuel vapour admission
• CPC Class Codes: F02M 35/104 Intake manifolds
• CPC Class Codes: F05D 2220/40 in turbochargers
• CPC Class Codes: F05D 2230/60 Assembly methods
• CPC Class Codes: F05D 2240/11 Shroud seal segments
• CPC Class Codes: F05D 2240/12 Fluid guiding means, e.g. vanes
• CPC Class Codes: F05D 2240/14 Casings or housings protecting or supporting assemblies within
• CPC Class Codes: F05D 2240/15 Heat shield
• CPC Class Codes: F05D 2240/20 Rotors
• CPC Class Codes: F05D 2260/311 : of the frangible or shear type
• CPC Class Codes: Y02T 10/12 : Improving ICE efficiencies

Abstract

A turbocharger is provided that includes a turbine housing including a gas inlet passage. A turbine wheel has a plurality of blades and is arranged in the turbine housing. A bearing housing is connected to the turbine housing. A shaft is rotatably supported in the bearing housing and connected to the turbine wheel. A shroud is arranged in surrounding relation to at least a portion of the turbine wheel, the shroud being arranged in spaced relation from and not in contact with the turbine housing. A fastening system secures the shroud relative to the bearing housing. The fastening system is configured to fracture when a force is exerted on the shroud corresponding to at least a portion of the turbine wheel contacting the shroud.

Claims

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 about a rotational axis;

a bearing housing connected to the turbine housing;

a shaft rotatably supported in the bearing housing and connected to the turbine wheel;

a shroud arranged in surrounding relation to at least a portion of the turbine wheel, the shroud being arranged in axially spaced relation from the turbine housing;

the turbine housing including an inner surface facing a radially inward direction and positioned radially inward of the gas inlet passage;

the shroud including an outer surface facing a radially outward direction and positioned radially inward of the gas inlet passage, and the outer surface further facing the inner surface of the turbine housing and extending circumferentially around the rotational axis of the turbine wheel; and

a fastening system securing the shroud at a fixed position relative to the bearing housing, and including a fastener positioned radially inward of the outer surface of the shroud and the inner surface of the turbine housing, and the fastener being configured to fracture when a force is exerted on the shroud corresponding to the turbine wheel contacting the shroud when the turbine wheel is rotating.

2. The turbocharger of claim 1 further including a heat shield that is secured to the bearing housing and wherein the fastening system secures the shroud to the heat shield.

3. The turbocharger of claim 2 wherein the fastening system comprises a plurality of shear bolts, and wherein the fastener is one of the plurality of shear bolts.

4. The turbocharger of claim 3 further including a nozzle ring interposed between the shroud and the heat shield, the nozzle ring being disposed around the turbine wheel and including a plurality of vanes with flow channels being defined between the vanes that are in fluid communication with the gas inlet passage and with the turbine wheel.

5. The turbocharger of claim 4 wherein the nozzle ring is integrally formed with the shroud.

6. The turbocharger of claim 5 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 and that extends in a direction parallel to a rotational axis of the turbine wheel.

7. The turbocharger of claim 3 wherein each shear bolt has an associated spring washer.

8. The turbocharger of claim 3 wherein each shear bolt is trapped at a first end between the shroud and the turbine housing and at a second end between the heat shield and the bearing housing.

9. The turbocharger of claim 1 wherein the shroud is configured to be rotatable relative to turbine housing when the fastener of the fastening system fractures.

10. A method for dissipating energy resulting from failure of a rotating turbine wheel in a turbocharger, the turbine wheel being arranged in a turbine housing and being connected to a shaft that is rotatably supported in a bearing housing, the method comprising:

arranging a shroud in surrounding relation to at least a portion of the turbine wheel, the shroud being arranged in axially spaced relation from the turbine housing; and

securing the shroud relative to the bearing housing with a fastening system configured to fracture when a force is exerted on the shroud corresponding to at least a portion of the turbine wheel contacts the shroud while the turbine wheel is rotating, wherein the shroud is configured to rotate relative to the turbine housing when a fastener in the fastening system fractures, and wherein a turbine nozzle fluidly connects the gas inlet passage to the turbine wheel and a portion of the shroud extends in an axial direction toward the bearing housing and is positioned in a gas flow path extending through the turbine nozzle between the gas inlet passage and the turbine wheel.

11. The method of claim 10 wherein the securing the shroud further includes securing the shroud with a fastening system that secures the shroud to a heat shield that is secured to the bearing housing.

12. The method of claim 11 wherein the securing the shroud further includes securing the shroud with a fastening system that comprises a plurality of shear bolts.

13. The method of claim 12 further including providing a nozzle ring interposed between the shroud and the heat shield, the nozzle ring being 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.

14. The method of claim 13 wherein the providing a nozzle ring further includes providing a nozzle ring where the nozzle ring is integrally formed with the shroud.

15. The method of claim 13 wherein the providing a nozzle ring further includes providing a nozzle ring including a plurality of vanes where 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 and that extends in a direction parallel to a rotational axis of the turbine wheel.

16. 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 about a rotation axis of the turbine wheel;

a bearing housing connected to the turbine housing;

a shaft rotatably supported in the bearing housing and connected to the turbine wheel;

a shroud arranged in surrounding relation to at least a portion of the turbine wheel, the shroud being arranged in spaced relation from and not in contact with the turbine housing;

the turbine housing including an inner surface facing a radially inward direction and positioned radially inward of the gas inlet passage;

the shroud including an outer surface facing a radially outward direction and positioned radially inward of the gas inlet passage, and the outer surface further facing the inner surface of the turbine housing and extending circumferentially around the rotational axis of the turbine wheel; and

a fastening system securing the shroud at a fixed position relative to the bearing housing, and including a fastener positioned radially inward of the outer surface of the shroud and the inner surface of the turbine housing, and being configured to fracture when a force is exerted on the shroud corresponding to the turbine wheel contacting the shroud when the turbine wheel is rotating.

17. The engine of claim 16 further including a heat shield that is secured to the bearing housing and wherein the fastening system secures the shroud to the heat shield.

18. The engine of claim 17 wherein the fastening system comprises a plurality of shear bolts.

19. The engine of claim 18 further including a nozzle ring interposed between the shroud and the heat shield, the nozzle ring being 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.

20. The engine of claim 19 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 and that extends in a direction parallel to a rotational axis of the turbine wheel.