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 flexible gas connection joint for use with an exhaust gas recirculation system is located between an engine exhaust manifold and a turbocharger. The flexible joint comprises a hot pipe for connection with an exhaust gas source. The hot pipe has a first end for connecting with the exhaust gas source, and has a second oppositely positioned end for connecting with an exhaust gas receiving member. The hot pipe second end includes a generally cylindrical outside surface. An adapter is coupled to the hot pipe second end for receiving exhaust gas therefrom. The adapter has a cylindrical inside diameter, and the hot pipe second end is disposed within the cylindrical inside diameter. The hot pipe second end has a radiused outside surface for enabling three-dimensional movement of the hot pipe second end within the adapter. The flexible joint can include a sealing ring interposed between concentric hot pipe and adapter surfaces for providing a leak-tight seal therebetween.

Abstract: Butterfly valves of this invention generally comprise a flapper element that is rotatably disposed within an annular bore of a valve housing. The valve may be configured to provide an improved degree of gas flow control sensitivity from a closed to a partially opened position through the use of projections that extend radially inwardly from the housing bore, are positioned at diametrically opposed positions within the bore, and that are specifically configured to provide a gradual increase in gas flow across the valve as the flapper is moved from a closed position to a partially opened position. The butterfly valve may be configured having further projections that extend radially inwardly a distance therein, that are positioned at diametrically opposed positions in the bore, and that include faces that are sized and shaped to cooperate with respective opposed surfaces of the flapper to seal off gas flow within the bore when the flapper is placed into a closed position.

Abstract: A flexible gas connection joint for use with an exhaust gas recirculation system is located between an engine exhaust manifold and a turbocharger. The flexible joint comprises a hot pipe for connection with an exhaust gas source. The hot pipe has a first end for connecting with the exhaust gas source, and has a second oppositely positioned end for connecting with an exhaust gas receiving member. The hot pipe second end includes a generally cylindrical outside surface. An adapter is coupled to the hot pipe second end for receiving exhaust gas therefrom. The adapter has a cylindrical inside diameter, and the hot pipe second end is disposed within the cylindrical inside diameter. The hot pipe second end has a radiused outside surface for enabling three-dimensional movement of the hot pipe second end within the adapter. The flexible joint can include a sealing ring interposed between concentric hot pipe and adapter surfaces for providing a leak-tight seal therebetween.