Abstract: There is provided a seal assembly comprising: a first component and a second component spaced apart from the first component so as to define a passage for the transfer of fluid from an inlet of the seal assembly to an outlet of the seal assembly, wherein the first component comprises a concavity at least partially defining the passage, and wherein no part of the second component extends into the portion of the passage bounded by the concavity.

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 turbocharger comprises a turbine wheel (5) mounted within a housing assembly (1, 3) for rotation about a turbine axis, a gas flow inlet passage (8) upstream of the turbine wheel (5), and a gas flow control mechanism (10, 16, 32) located within the housing assembly (1, 3) upstream of the turbine wheel (5) and operable to control gas flow through said gas flow inlet passage (9). An actuator assembly is mounted to the housing assembly and comprises: A lead screw including a lead screw shaft (37) defining a lead screw axis, and a lead screw nut (36) threadedly engaged on a threaded portion of the lead screw shaft (37). The lead screw (36, 37) being arranged so that rotation of one of said shaft and nut relative to the housing assembly produces linear movement in the other of said shaft and nut in the direction of the lead screw axis: The lead screw (36, 37) engages the gas flow control mechanism (10, 16, 32) at a location within a housing cavity defined within said housing assembly (1, 3).

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 turbocharger comprises a turbine wheel (5) mounted within a housing assembly (1, 3) for rotation about a turbine axis, a gas flow inlet passage (8) upstream of the turbine wheel (5), and a gas flow control mechanism (10, 16, 32) located within the housing assembly (1, 3) upstream of the turbine wheel (5) and operable to control gas flow through said gas flow inlet passage (9). An actuator assembly is mounted to the housing assembly and comprises: A lead screw including a lead screw shaft (37) defining a lead screw axis, and a lead screw nut (36) threadedly engaged on a threaded portion of the lead screw shaft (37). The lead screw (36, 37) being arranged so that rotation of one of said shaft and nut relative to the housing assembly produces linear movement in the other of said shaft and nut in the direction of the lead screw axis: The lead screw (36, 37) engages the gas flow control mechanism (10, 16, 32) at a location within a housing cavity defined within said housing assembly (1, 3).