Actuation system for variable nozzle turbine

Claim 2

A turbocharger, for use in association with an engine, comprising: an exhaust gas driven turbine rotatably mounted to a shaft having a compressor impeller thereon; a compressor housing enclosing said compressor impeller; a center housing including bearing means for rotatably supporting the shaft; a turbine housing forming a volute therein for directing exhaust gas from said engine to said shaft; a backplate mounted between said center housing and said turbine housing and defining an annular cavity therearound; an annular unison ring positioned within said annular cavity of said backplate; a turbine side wall, independent of said turbine housing, said side wall defining one side of an annular passage, said unison ring and backplate defining the other side; a plurality of vanes pivotably mounted between said backplate and said turbine side wall; means for pivoting said plurality of vanes; and at least three spacers between said backplate and said turbine side wall.

Claim 3

The turbocharger according to claim 1 wherein said turbine housing has an annular slot therein concentric to the axis of shaft rotation, said side wall being located within said slot.

Claim 4

The turbocharger according to claim 2 further including a flexible seal between said turbine housing and said side wall.

Claim 5

The turbocharger according to claim 1 wherein said spacers have an axial length greater than said vanes.

Claim 6

The turbocharger according to claim 2 wherein said unison ring includes at least three rollers attached thereto.

Claim 7

The turbocharger according to claim 5 wherein said means for pivoting comprises a drive pin associated with each vane and a plurality of slots in said unison ring for accepting said drive pins.

Claim 8

The turbocharger of claim 6 wherein said backplate defines a track means for guiding said rollers.

Claim 9

The turbocharger according to claim 7 wherein said track means is a flat surface radially about the turbocharger shaft located on said backplate.

Claim 10

The turbocharger of claim 8 wherein said track means includes a V-shaped coaxial groove therein.

Claim 11

The turbocharger of claim 9 wherein said backplate further includes a cut-out segment for each of said rollers extending to the same radial depth as said groove.

Claim 12

A variable nozzle turbocharger including an exhaust gas driven turbine rotatably mounted to a shaft having a compressor impeller thereon, a compressor housing enclosing said compressor impeller, a center housing including bearing means for rotatably supporting the shaft, a turbine housing forming a volute therein for directing the exhaust gas from an engine through an annular passage to said turbine; a plurality of vanes pivotably mounted within said annular passage, and an assembly for pivoting said plurality of vanes comprising: a backplate member mounted between said center housing and turbine housing and defining an annular cavity therein and a track radially about the turbocharger shaft; a unison ring including a plurality of slots and at least three rollers attached to said unison ring, said rollers positioned on said track; a vane driven pin associated with each vane, each vane drive pin extending into one of said slots in said unison ring; means for rotating said unison ring; and cut-out segments spaced about the track, said cut-out segments being angularly spaced and aligned with said rollers.

Claim 13

A variable nozzle turbocharger including an exhaust gas driven turbine rotatably mounted to a shaft having a compressor impeller thereon, a compressor housing enclosing said compressor impeller, a center housing including bearing means for rotatably supporting the shaft, a turbine housing forming a volute therein for directing the exhaust gas from an engine through an annular passage to said turbine; a plurality of vanes pivotably mounted within said annular passage, and an assembly for pivoting said plurality of vanes comprising: a backplate member mounted between said center housing and turbine housing and defining an annular cavity therein and a track radially about the turbocharger shaft; a unison ring including a plurality of slots and at least three rollers attached to said unison ring, said rollers positioned on said track; a vane driven pin associated with each vane, each vane drive pin extending into one of said slots in said unison ring; means for rotating said unison ring; and cut-out segments spaced about the track, said cut-out segments being angularly spaced and aligned with said rollers.

Claim 14

The assembly of claim 11 further including spring means associated with each roller for absorbing any radial thermal expansion of said backplate.

Claim 15

The assembly according to claim 12 wherein said means comprises: a bushing around the end of the axle within said roller; an axle attached to the unison ring; a leaf spring under the axle and between the axle and bushing; and means for rotatably securing said roller to said axle.

Claim 16

In a turbocharger, a turbine backplate comprising: a generally circular body having a central bore for acceptance of a turbocharger shaft; a recess portion defining at least three track sections; each track section being an equal radial distance from and coaxial to said central bore; and raised segmented sections between each of said track sections.

Claim 17

In a turbocharger, a turbine backplate comprising: a generally circular body having a central bore for acceptance of a turbocharger shaft; a recess portion defining at least three track sections; each track section being an equal radial distance from and coaxial to said central bore; and raised segmented sections between each of said track sections.

Claim 18

The backplate according to claim 14 further including a groove in said track section.

Claim 19

The backplate according to claim 15 further including a cut out segment in each of said track sections extending to the same radial depth as said groove.

Claim 20

A variable nozzle turbocharger comprising: an exhaust gas driven turbine rotatably mounted to a shaft having a compressor impeller thereon; a compressor housing enclosing said compressor impeller; a center housing including bearing means for rotatably supporting the shaft; a turbine housing forming a volute therein for directing exhaust gas from an engine through an annular passage to said turbine; a backplate member mounted between said center housing and said turbine housing and defining a cavity therein; an annular side wall located within an annular slot in said turbine housing; a plurality of vanes pivotably mounted between said side wall and said backplate member in said annular passage; means for pivoting said plurality of vanes, said means cooperating with said backplate on one side and the side wall on the other to define the annular passage; and at least three bolts including a spacer securing said side wall to said backplate at the desired axial distance.

Claim 21

A variable nozzle turbocharger comprising: an exhaust gas driven turbine rotatably mounted to a shaft having a compressor impeller thereon; a compressor housing enclosing said compressor impeller; a center housing including bearing means for rotatably supporting the shaft; a turbine housing forming a volute therein for directing exhaust gas from an engine through an annular passage to said turbine; a backplate member mounted between said center housing and said turbine housing and defining a cavity therein; an annular side wall located within an annular slot in said turbine housing; a plurality of vanes pivotably mounted between said side wall and said backplate member in said annular passage; means for pivoting said plurality of vanes, said means cooperating with said backplate on one side and the side wall on the other to define the annular passage; and at least three bolts including a spacer securing said side wall to said backplate at the desired axial distance.

Claim 22

The turbocharger of claim 17 wherein said annular side wall is independent of said turbine housing.

Claim 23

The turbocharger of claim 18 including an annular seal between said side wall and said turbine housing.

Claim 24

The turbocharger of claim 17 wherein said means for pivoting comprises: a drive pin integral with each vane; an annular unison ring including a plurality of slots in one side thereof for accepting said drive pins; and means for rotating said unison ring with respect to said backplate.

Claim 25

The turbocharger of claim 17 wherein said backplate comprises: a generally circular body having a central bore for acceptance of a turbocharger shaft; a recess portion defining at least three track sections, each track section being coaxial to said central bore; and raised segmented sections between each of said track sections.

Claim 26

The turbocharger of claim 21 wherein said backplate further includes a coaxial groove in said track section.

Claim 27

The turbocharger of claim 22 further including a cut-out segment in each of said track sections extending to the same radial depth as said groove.

Claim 30

The method of claim 24 wherein said step of pivotably locating the plurality of vanes includes spacing the backplate and annular side wall a constant distance apart from one another.

Claim 31

The method of claim 24 wherein further including the step of sealing the annular side wall to prevent exhaust gas flow behind the annular side wall around said annular passageway.

Claim 32

The method of claim 24 wherein the step of rotatably locating the unison ring includes the steps of: securing at least two rollers to said unison ring; indexing said rollers with cut-out segments formed in the backplate; and rotating said rollers in a track formed in the backplate away from said cut-out segments.

Claim 33

The method of claim 27 further including the step of spring-loading the rollers in said track.