VARIABLE GEOMETRY TURBOCHARGER

In a variable geometry turbocharger, with a turbine housing having a standar d inlet for exhaust gas and an outlet to the exhaust system of the engine, a volute connected to the inlet and an integral outer nozzle, a plurality of vanes having rotation posts extending from a first surface substantially parallel to the outer nozzle wall to provide the variable nozzle; the posts received in circumferentially spaced apertures in the outer nozzle wall; the vanes having actuation tabs extending from the opposite surfaces of the vanes; a unison ring engaged between the centre housing and the vanes and having a plurality of profiled slots equal in numb er to the vanes; the slots oriented obliquely to a circumference of the unison ring and receive t he tabs; the profiled surfaces of the slots engage the substantially flat sides of the tabs on different surfaces during the translation to provide optimum control and wear reduction; a radial slot wit h crank shaft having a pin engaging the radial slot to actuate the unison ring, the crank shaft moveable continuously from a first position to a second position to cause the pin to translate in the radial slot; an integral hydraulic actuator providing the actuation mechanism for the crank shaft.