Abstract: A variable geometry turbine assembly comprising an inlet passageway, extending radially inwards towards a turbine wheel, defined between a surface of a movable wall member and a facing wall and an actuation mechanism arranged to move the movable wall member axially and comprising a cam member provided with at least one formation and a carrier member axially coupled to at least one co-operating formation, wherein one of the at least one formation and the at least one co-operating formation is a radially extending formation, the at least one formation or the at least one co-operating formation extending in both the circumferential direction and the axial direction such that as the cam member is rotated relative to the carrier member, the at least one formation and the at least one co-operating formation engage such the movable wall member is moved in the axial direction.

Abstract: A variable geometry turbine assembly comprising an inlet passageway, extending radially inwards towards a turbine wheel, defined between a surface of a movable wall member and a facing wall and an actuation mechanism arranged to move the movable wall member axially and comprising a cam member provided with at least one formation and a carrier member axially coupled to at least one co-operating formation, wherein one of the at least one formation and the at least one co-operating formation is a radially extending formation, the at least one formation or the at least one co-operating formation extending in both the circumferential direction and the axial direction such that as the cam member is rotated relative to the carrier member, the at least one formation and the at least one co-operating formation engage such the movable wall member is moved in the axial direction.

Abstract: A turbine wheel mounted within a housing rotating about a turbine axis; a gas flow control passage upstream of the turbine wheel between a radial first surface of a movable wall member and a facing wall of the housing, the movable wall member comprising second and third surfaces opposing the first surface. The movable wall member moves in an axial direction to vary the size of the gas flow control passage. A first gas region of the turbine, being upstream of the gas flow control passage, includes a portion of the gas flow control passage; a second gas region of the turbine downstream of the gas flow control passage containing the turbine wheel; and a third gas region of the turbine downstream of the turbine wheel. The first gas region comprises the first and second surfaces, and the second gas region or third gas region comprises the third surface.

Abstract: A variable geometry turbine of the kind used in a turbocharger has a variable geometry element such as a nozzle ring that is operated by an actuator. The actuator comprises a motor which drives a cross-shaft in rotation. The cross-shaft in turn drives a pair of guide rods on which the nozzle ring is supported in translation so as to move the nozzle ring and control the width of the inlet passage of the turbine. The cross-shaft and guide rods are drivingly engaged by a rack and pinion or thread or another toothed or threaded formation suitable for converting rotational movement into translational movement. The cross-shaft can be located in close proximity to the guide rods and the output of the motor shaft so as to provide a compact package. Moreover, the torque required to resist movement of the nozzle ring in operation is much reduced in comparison to existing designs.

Abstract: A variable geometry turbine comprises a turbine wheel mounted within a housing for rotation about a turbine axis; and a gas flow control passage upstream of said turbine wheel, the gas flow control passage being defined at least in part between a radial first surface of a movable wall member and a facing wall of the housing, the movable wall member also comprising second and third surfaces which oppose the first surface. The movable wall member is movable in an axial direction so as to vary the size of the gas flow control passage. There is a first gas region of the turbine, a portion of which is upstream of the gas flow control passage, the first gas region including at least a portion of the gas flow control passage; a second gas region of the turbine downstream of the gas flow control passage which contains the turbine wheel; and a third gas region of the turbine downstream of the turbine wheel.

Abstract: A variable geometry turbine of the kind used in a turbocharger has a variable geometry element such as a nozzle ring that is operated by an actuator. The actuator comprises a motor which drives a cross-shaft in rotation. The cross-shaft in turn drives a pair of guide rods on which the nozzle ring is supported in translation so as to move the nozzle ring and control the width of the inlet passage of the turbine. The cross-shaft and guide rods are drivingly engaged by a rack and pinion or thread or another toothed or threaded formation suitable for converting rotational movement into translational movement. The cross-shaft can be located in close proximity to the guide rods and the output of the motor shaft so as to provide a compact package. Moreover, the torque required to resist movement of the nozzle ring in operation is much reduced in comparison to existing designs.