Patent ID: 8480357

Claim:
A variable geometry turbocharger assembly, comprising: a turbine housing defining an inlet for exhaust gas and an outlet; a turbine wheel within the turbine housing and attached to a shaft; a nozzle defining a nozzle passage for exhaust flow to the turbine wheel; a plurality of vanes disposed within the nozzle passage, each vane mounted on a bearing pin and each vane configured to pivot about an axis defined by the respective bearing pin; a center housing connected to the turbine housing and comprising an outer pilot surface defining an outer radius; at least one guide pin secured to the center housing adjacent to the outer pilot surface, each guide pin defining a wear surface that extends to a radius which is larger than the outer radius of the outer pilot surface proximate each guide pin; and a unison ring connected to the vanes and rotatable substantially about a longitudinal axis defined by the shaft for pivoting the vanes about the respective axes, the unison ring defining a radially inner surface; wherein the radially inner surface of the unison ring makes sliding contact with the wear surface of each guide pin and/or the outer pilot surface of the center housing as the unison ring rotates substantially about the longitudinal axis, each guide pin and/or the outer pilot surface restraining radial movement of the unison ring while allowing for rotational movement of the unison ring.