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 assembly employing the present invention includes a center housing, a compressor housing attached to one side of the center housing, and a turbine housing attached to another side of the center housing. A plurality of movable vanes is disposed within the turbine housing, and a unison ring is rotatably disposed within the turbine housing to move the vanes in unison. The turbocharger includes a unison ring assembly of this invention that includes an insert that is separate from and attached to the center housing. The support has one or more surfaces to carry the unison ring, and the unison ring is rotatably positioned on the support. The support further provides a space that isolates the unison ring from making contact with contacting the center housing. A heat shroud optionally extends radially inwardly along the center housing and is retained into position by the support.

Abstract: Variable geometry turbochargers include a turbine housing having an exhaust gas inlet and outlet, a volute connected to the inlet, and typically a nozzle wall adjacent the volute. The turbine housing includes a bypass exhaust gas flow port disposed internally therein having an inlet opening positioned upstream from the turbine wheel, and a outlet opening positioned downstream from the turbine wheel. The inlet opening is exposed for facilitating bypass exhaust gas flow through the turbocharger when a respective vane is actuated or moved into an open position. The turbine housing may also include a specially configured nozzle wall terminal edge designed to work with vanes having a recessed underside surface to permit additional bypass exhaust gas flow within the turbocharger when the vanes are actuated in an open position.