Patent ID: 7097432
Filing Date: 2006-08-29
Classification: F01D,F05D

Abstract:
1. A turbocharger comprising: a case having a turbine housing receiving exhaust gas from an exhaust manifold of an internal combustion engine at an inlet and having an exhaust outlet, a compressor housing having an air inlet and a first volute, and a center housing intermediate the turbine housing and compressor housing; a turbine wheel carried within the turbine housing and extracting energy from the exhaust gas, said turbine wheel connected to a shaft extending from the turbine housing through a shaft bore in the center housing; a bearing carried in the shaft bore of the center housing, said bearing supporting the shaft for rotational motion; a compressor impeller connected to the shaft opposite the turbine wheel and enclosed within the compressor housing; a substantially cylindrical piston, concentric to the turbine wheel and movable parallel to an axis of rotation of the turbine wheel; a plurality of vanes extending substantially parallel to the axis of rotation from a first end of the piston proximate a back disc of the turbine wheel, each vane having a first portion with a first cord and depth and a second portion intermediate the first portion and the first end of the piston, the second portion having a second cord and depth larger than the first cord and depth, the first and second portions being characterized in that the larger cord and depth of the second portion provides a step around the first portion; a heat shield engaged at its outer circumference between the turbine housing and center housing and extending radially inward toward the axis of rotation, said heat shield further having a plurality of slots having cord and depth to closely receive the first portion of the vanes; and means for moving the piston from a first position wherein the first end is proximate the heat shield to a second position wherein the first end is distal the heat shield, the second portion of the vanes engaging the heat shield and sealing the slots with the piston in the first position.