Patent attributes
Variable turbocharger apparatus comprising a housing, a compressor, a turbine, a chamber which extends around the turbine, a bearing assembly for the turbine, vanes mounted in the chamber, a piston positioned between the housing and the turbine, a control device controlling the piston, a piston end nearest the bearing assembly defining a gap, which is variable in size to control exhaust gases acting on the turbine, at least one bypass aperture which opens to allow exhaust gases that are not required for acting on the turbine to bypass the turbine, and sliding of the piston being such that the piston is always maintained in a position which enables the turbine speed to be controlled through the gap alone when there is no bypass and through the gap and the bypass aperture when there is bypass.