Abstract: A variable geometry turbocharger assembly comprises a unison ring which rotates about a longitudinal axis defined by a shaft on which a turbine wheel and compressor wheel are attached in order to pivot a plurality of vanes and thereby control a flow of exhaust gas to the turbine wheel. The unison ring rotates on at least one guide pin which is secured to the turbocharger. The guide pins may be press-fit into apertures in a center housing at an outer pilot surface. In other embodiments the guide pins may be press-fit into a different part of the turbocharger such as a nozzle ring. The guide pins may each have a wear surface which defines a circumferential radius of curvature which is substantially equal to a circumferential radius of curvature of a radially inner surface of the unison ring.

Abstract: A variable geometry turbocharger assembly comprises a unison ring which rotates about a longitudinal axis defined by a shaft on which a turbine wheel and compressor wheel are attached in order to pivot a plurality of vanes and thereby control a flow of exhaust gas to the turbine wheel. The unison ring rotates on at least one guide pin which is secured to the turbocharger. The guide pins may be press-fit into apertures in a center housing at an outer pilot surface. In other embodiments the guide pins may be press-fit into a different part of the turbocharger such as a nozzle ring. The guide pins may each have a wear surface which defines a circumferential radius of curvature which is substantially equal to a circumferential radius of curvature of a radially inner surface of the unison ring.

Abstract: A compressor diffuser for a vehicle engine turbocharger, the diffuser comprising: a diffuser housing having a gas flow path having a side wall connecting a gas inlet to a gas outlet; a plurality of pivotally mounted diffuser vanes arranged in the flow path to control gas flow, and a vane angle control device for adjusting the angle of each of the plurality of vanes in the flow path; the control device comprising a unison ring coupled to the plurality of vanes in such a way that rotation of the unison ring pivots each of the vanes by interaction of a cam surface with a respective cam follower.

Abstract: A compressor diffuser for a vehicle engine turbocharger, the diffuser comprising: a diffuser housing having a gas flow path having a side wall connecting a gas inlet to a gas outlet; a plurality of pivotally mounted diffuser vanes arranged in the flow path to control gas flow, and a vane angle control device for adjusting the angle of each of the plurality of vanes in the flow path; the control device comprising a unison ring coupled to the plurality of vanes in such a way that rotation of the unison ring pivots each of the vanes by interaction of a cam surface with a respective cam follower.

Abstract: A variable geometry turbocharger includes vanes disposed therein having an inner airfoil surface oriented adjacent a turbine wheel, and an outer airfoil surface oriented opposite and parallel to the inner airfoil surface. The vane includes first and second axial surfaces that are each positioned perpendicular to and interposed between the inner and outer airfoil surfaces. A vane leading edge is positioned along a first inner and outer airfoil surface junction, and a trailing edge is positioned along a second inner and outer airfoil surface junction. One or more of the first and second axial surfaces have a composite construction comprising a solid section that extends a distance from the leading edge towards the trailing edge, and a cored-out section that extends a distance from the trailing edge towards the leading edge.

Abstract: A variable geometry turbocharger employs multiple vanes in the turbine inlet with a unison ring and integral cast wall in the turbine housing forming the nozzle walls. The unison ring incorporates actuation slots receiving tabs on the vanes for opening the closing the nozzle area upon rotation of the unison ring. An integral electrohydraulic actuator rotates the unison ring through a rack and pinion driven crank shaft with direct position feedback to the spring biased variable current solenoid via a cam on the crank shaft.