US Patent 7097432 Sliding vane turbocharger with graduated vanes

A turbocharger having a variable geometry turbine inlet incorporating a cylindrical piston movable to vary the area of the inlet nozzle into the turbine. Vanes mounted to the piston for flow control in the nozzle are received through a slotted heat shield which provides smooth aerodynamic flow into the turbine blades. The vanes additionally incorporate a step having larger cord and depth that engages the surface of the heat shield and seals the slots with the piston in a closed position. An axial actuator is attached for operation of the piston.