Turbocharger vane

1. A variable nozzle device for use with a wheel, comprising:

an annular nozzle passage formed by a gap between two opposing wall members; and

at least one vane positioned around the wheel in said annular nozzle passage and being rotatably supported by a shaft that is rotatable around a shaft axis of rotation;

wherein the shaft is configured to rotate the vane through a range of vane orientations between a fully open position and a fully closed position;

wherein an aerodynamic center of pressure of the vane is positioned with respect to the shaft axis of rotation such that, with the vane at the fully closed position, the aerodynamic center of pressure is radially outward with respect to the wheel from its position with the vane at the fully open position;

wherein said vane is a sheet of material curved to form an outer surface in the shape of an aerodynamic profile, the vane having a first sheet portion and a second sheet portion, each sheet portion extending from a leading edge of the vane to a trailing edge of the vane on an opposite side of the vane from the other sheet portion, said vane being attached to the shaft;

wherein the second sheet portion extends closer to the shaft axis of rotation than the first sheet portion; and

wherein the shaft axis of rotation extends between the first sheet portion and the second sheet portion.

2. The variable nozzle device according to claim 1 , wherein the aerodynamic center of pressure of the vane is positioned with respect to the shaft axis of rotation such that aerodynamic forces on the vane from flow through the nozzle device will torsionally load the shaft in the same direction throughout the full range of vane orientations to which the shaft is configured to rotate the vane.

3. A variable nozzle device for use with a wheel, comprising:

an annular nozzle passage formed by a gap between two opposing wall members; and

at least one vane positioned around the wheel in said annular nozzle passage and being rotatably supported by a shaft that is rotatable around a shaft axis of rotation;

wherein the shaft is configured to rotate the vane through a range of vane orientations between a fully open position and a fully closed position;

wherein an aerodynamic center of pressure of the vane is positioned with respect to the shaft axis of rotation such that, with the vane at the fully closed position, the aerodynamic center of pressure is radially outward with respect to the wheel from its position with the vane at the fully open position;

wherein the vane is a sheet of material curved to form an outer surface in the shape of an aerodynamic profile;

wherein the vane has an inner surface with a profile mimicking the aerodynamic profile of the outer surface;

wherein the shaft has a wind-stream portion defining a noncircular first contact surface and a noncircular second contact surface, the noncircular first contact surface and the noncircular second contact surface being configured with curves that match and conformingly receive respective portions of the vane inner surface over respective extended chord-wise lengths of the vane inner surface; and

wherein the noncircular first contact surface and the noncircular second contact surface are attached to the respective portions of the vane inner surface.

4. The variable nozzle device according to claim 3 , wherein:

the wind-stream portion defines grooves in the shaft that form the noncircular first contact surface and the noncircular second contact surface;

the grooves defined by the wind-stream portion of the shaft include two chord-wise ends that align with a periphery of a cylindrical portion of the shaft immediately adjacent the wind-stream portion of the shaft; and

the noncircular contact surfaces each fully extend from one chord-wise end to the other of each groove.

5. The variable nozzle device according to claim 3 , wherein:

each of the noncircular first contact surface and the noncircular second contact surface has an attachment to its respective portion of the vane inner surface; and

the attachment is configured to extend more in a chord-wise direction than in a span-wise direction along the noncircular contact surface.

6. A variable nozzle device for use with a wheel, comprising:

an annular nozzle passage formed by a gap between two opposing wall members; and

at least one vane positioned around the wheel in said annular nozzle passage and being rotatably supported by a shaft that is rotatable around a shaft axis of rotation;

wherein the shaft is configured to rotate the vane through a range of vane orientations between a fully open position and a fully closed position;

wherein an aerodynamic center of pressure of the vane is positioned with respect to the shaft axis of rotation such that, with the vane at the fully closed position, the aerodynamic center of pressure is radially outward with respect to the wheel from its position with the vane at the fully open position; and

wherein a wind-stream portion of the shaft does not extend along the shaft axis of rotation.

7. A variable nozzle device for use with a wheel, comprising:

an annular nozzle passage formed by a gap between two opposing wall members; and

at least one vane positioned around the wheel in said annular nozzle passage and being rotatably supported by a shaft that is rotatable around a shaft axis of rotation;

wherein the shaft is configured to rotate the vane through a range of vane orientations between a fully open position and a fully closed position;

wherein an aerodynamic center of pressure of the vane is positioned with respect to the shaft axis of rotation such that, with the vane at the fully closed position, the aerodynamic center of pressure is radially outward with respect to the wheel from its position with the vane at the fully open position; and

wherein the shaft includes cylindrical load bearing portions on two longitudinal ends of a wind-stream portion.

8. A variable nozzle device comprising:

an annular nozzle passage formed by a gap between two opposing wall members; and

at least one vane extending in said annular nozzle passage and being rotatably supported by a shaft that is rotatable around a shaft axis of rotation;

wherein said vane is a sheet of material curved to form an outer surface in the shape of an aerodynamic profile, the vane having an inner surface with a profile mimicking the aerodynamic profile of the outer surface;

wherein the shaft has a wind-stream portion defining a noncircular first contact surface and a noncircular second contact surface, the noncircular first contact surface and the noncircular second contact surface being configured with curves that match and conformingly receive respective portions of the vane inner surface over respective extended chord-wise lengths of the vane inner surface;

wherein the noncircular first contact surface and the noncircular second contact surface are attached to the respective portions of the vane inner surface;

wherein the wind-stream portion defines grooves in the shaft that form the noncircular first contact surface and the noncircular second contact surface;

wherein the grooves defined by the wind-stream portion of the shaft include two chord-wise ends that align with a periphery of a cylindrical portion of the shaft immediately adjacent the wind-stream portion of the shaft; and

wherein the noncircular first contact surface and the noncircular second contact surface each fully extend from one chord-wise end to the other of each groove.

9. The variable nozzle device according to claim 8 , wherein:

each of the noncircular first contact surface and the noncircular second contact surface has an attachment to its respective portion of the vane inner surface; and

the attachment is configured to extend more in a chord-wise direction than in a span-wise direction along the contact surface.

10. The variable nozzle device according to claim 8 , wherein the shaft includes cylindrical load bearing portions on two longitudinal ends of the wind-stream portion.