Heat shield for mixed flow turbine wheel turbochargers

Patent metadata

Field	Value
Publication number	US-10669889-B2
Application number	US-201515114480-A
Country	US
Kind code	B2
Filing date	Jan 29, 2015
Priority date	Feb 4, 2014
Publication date	Jun 2, 2020
Grant date	Jun 2, 2020

Abstract

A turbocharger (18) includes a shaft (20), a mixed flow turbine wheel (40) including a wheel hub (44) and blades having tips (42), and a heat shield (11). The heat shield (11) has a side wall, an end (19), and a contoured front edge (13) that connects the sidewall (16) and the end (19). The front edge (13) of the heat shield (11) defines a slope that forms an imaginary line that is angled relative to the sidewall (16) and the end (19), and intersects an axis of rotation of the shaft (20). The heat shield (11) resides at a position that is between a bearing housing (22) of the turbocharger (18) and the turbine wheel (40), and axially inward relative to an axially-facing surface of a turbine volute (24), and between the bearing housing (22) and the turbine wheel (40).

First claim

We claim:

1. A turbocharger ( 18 ) comprising
a shaft ( 20 ) having an axis of rotation (R),
a mixed flow turbine wheel ( 40 ) connected to the shaft, the turbine wheel ( 40 ) including a wheel hub ( 44 ) and blades each having a single tip ( 42 ) at the radially outermost portion of the blades, and
a heat shield ( 11 ) including a side wall ( 16 ), an end ( 19 ), and a contoured front edge ( 13 ) that connects the sidewall ( 16 ) and the end ( 19 ) that extends below the wheel hub ( 44 ),
wherein the heat shield ( 11 ) is disposed between the turbine wheel ( 40 ) and a bearing housing ( 22 ),
wherein the contoured front edge ( 13 ) of the heat shield ( 11 ) is inclined toward the blades such that the contoured front edge ( 13 ) defines a slope that forms an imaginary line ( 17 ) that is angled relative to the sidewall ( 16 ) and the end ( 19 ), and intersects the axis of rotation (R) of the shaft ( 20 ) at a non-perpendicular and non-parallel angle as a result of the incline of the contoured front edge ( 13 ),
an exhaust volute having an axially-inward edge, wherein the end of the heat shield resides at a position axially inward relative to the axially-inward edge of the exhaust volute so that the heat shield is out of the direct flow of exhaust gas and so that exhaust gas is directed from the exhaust volute, across variable guide vanes, directly onto the blade passage defined between the hub of the turbocharger wheel and an inner surface of the turbine housing, wherein the contoured front edge comprises a chamfered surface, wherein the imaginary line ( 17 ) defined by the contoured front edge ( 13 ) of the heat shield ( 11 ) forms an angle of 41 degrees to 43 degrees with the axis of rotation of the shaft ( 20 ).

2. A turbocharger ( 18 ) comprising
a shaft ( 20 ) having an axis of rotation (R),
a mixed flow turbine wheel ( 40 ) connected to the shaft, the turbine wheel ( 40 ) including a wheel hub ( 44 ) and blades each having a single tip ( 42 ) at the radially outermost portion of the blades, and
a heat shield ( 11 ) including a side wall ( 16 ), an end ( 19 ), and a contoured front edge ( 13 ) that connects the sidewall ( 16 ) and the end ( 19 ) that extends below the wheel hub ( 44 ),
wherein the heat shield ( 11 ) is disposed between the turbine wheel ( 40 ) and a bearing housing ( 22 ),
wherein the contoured front edge ( 13 ) of the heat shield ( 11 ) is inclined toward the blades such that the contoured front edge ( 13 ) defines a slope that forms an imaginary line ( 17 ) that is angled relative to the sidewall ( 16 ) and the end ( 19 ), and intersects the axis of rotation (R) of the shaft ( 20 ) at a non-perpendicular and non-parallel angle as a result of the incline of the contoured front edge ( 13 ),
an exhaust volute having an axially-inward edge, wherein the end of the heat shield resides at a position axially inward relative to the axially-inward edge of the exhaust volute so that the heat shield is out of the direct flow of exhaust gas and so that exhaust gas is directed from the exhaust volute, across variable guide vanes, directly onto the blade passage defined between the hub of the turbocharger wheel and an inner surface of the turbine housing, wherein the contoured front edge comprises a chamfered surface, wherein the contoured front edge ( 13 ) comprises a concave surface wherein the imaginary line is drawn through a first point of the concave surface that meets the sidewall ( 16 ) and a second point of the concave surface that meets the end ( 19 ).

3. A turbocharger ( 18 ) comprising
a shaft ( 20 ) having an axis of rotation (R),
a mixed flow turbine wheel ( 40 ) connected to the shaft, the turbine wheel ( 40 ) including a wheel hub ( 44 ) and blades each having a single tip ( 42 ) at the radially outermost portion of the blades, and
a heat shield ( 11 ) including a side wall ( 16 ), an end ( 19 ), and a contoured front edge ( 13 ) that connects the sidewall ( 16 ) and the end ( 19 ) that extends below the wheel hub ( 44 ),
wherein the heat shield ( 11 ) is disposed between the turbine wheel ( 40 ) and a bearing housing ( 22 ),
wherein the contoured front edge ( 13 ) of the heat shield ( 11 ) is inclined toward the blades such that the contoured front edge ( 13 ) defines a slope that forms an imaginary line ( 17 ) that is angled relative to the sidewall ( 16 ) and the end ( 19 ), and intersects the axis of rotation (R) of the shaft ( 20 ) at a non-perpendicular and non-parallel angle as a result of the incline of the contoured front edge ( 13 ),
an exhaust volute having an axially-inward edge, wherein the end of the heat shield resides at a position axially inward relative to the axially-inward edge of the exhaust volute so that the heat shield is out of the direct flow of exhaust gas and so that exhaust gas is directed from the exhaust volute, across variable guide vanes, directly onto the blade passage defined between the hub of the turbocharger wheel and an inner surface of the turbine housing, wherein a length of the contoured front edge of the heat shield ( 11 ) is 4 percent to 8 percent of a diameter of the heat shield ( 11 ).

4. The turbocharger ( 18 ) according to claim 3 wherein a length of the contoured front edge of the heat shield ( 11 ) is 4.5 percent to 5.5 percent of a diameter of the heat shield ( 11 ).

5. A turbocharger ( 18 ) comprising
a shaft ( 20 ) having an axis of rotation (R),
a mixed flow turbine wheel ( 40 ) connected to the shaft, the turbine wheel ( 40 ) including a wheel hub ( 44 ) and blades each having a single tip ( 42 ) at the radially outermost portion of the blades, and
a heat shield ( 11 ) including a side wall ( 16 ), an end ( 19 ), and a contoured front edge ( 13 ) that connects the sidewall ( 16 ) and the end ( 19 ) that extends below the wheel hub ( 44 ),
wherein the heat shield ( 11 ) is disposed between the turbine wheel ( 40 ) and a bearing housing ( 22 ),
wherein the contoured front edge ( 13 ) of the heat shield ( 11 ) is inclined toward the blades such that the contoured front edge ( 13 ) defines a slope that forms an imaginary line ( 17 ) that is angled relative to the sidewall ( 16 ) and the end ( 19 ), and intersects the axis of rotation (R) of the shaft ( 20 ) at a non-perpendicular and non-parallel angle as a result of the incline of the contoured front edge ( 13 ),
an exhaust volute having an axially-inward edge, wherein the end of the heat shield resides at a position axially inward relative to the axially-inward edge of the exhaust volute so that the heat shield is out of the direct flow of exhaust gas and so that exhaust gas is directed from the exhaust volute, across variable guide vanes, directly onto the blade passage defined between the hub of the turbocharger wheel and an inner surface of the turbine housing, wherein the contoured front edge comprises a chamfered surface, wherein a ratio of a diameter of the wheel hub ( 44 ) to a diameter of the turbine wheel ( 40 ) measured at the blade tips ( 42 ) is 0.8 to 0.9.

Assignees

• Borgwarner Inc

Inventors

• Chandramohanan Rajmohan T
• Williams Greg

Classifications

• F01D5/04

  for radial-flow machines or engines · CPC title

• F01D25/145 Primary

  Thermally insulated casings · CPC title

• F05D2220/40

  in turbochargers · CPC title

• F05D2250/314

  the axes being inclined in relation to each other · CPC title

• F05D2250/711

  convex · CPC title