Abstract: An improved compressor wheel assembly for a a turbocharger or the like includes a centrifugal compressor wheel having a boreless hub to substantially improve wheel fatigue life. The compressor wheel is formed as by casting from an aluminum alloy to include an integral mounting sleeve extending coaxially from the boreless hub and adapted for connection as by threading with a turbocharger shaft. An annular spacer ring of wear resistant material is mounted on the wheel mounting sleeve and defines wear resistant surfaces for supporting one or more seal rings within the bore of a compressor backplate opening, and for axially engaging an adjacent thrust bearing unit associated with the turbocharger shaft.

Abstract: A turbocharger having a variable nozzle vane assembly to be used in association with an engine. A plurality of pivotable vanes are mounted between the turbocharger backplate and unison ring on one side and an annular side wall, independent of the turbine housing on the other. Each vane includes a drive pin which pivots the vane in response to rotational movement of the unison ring.