Supercharger control for a supercharged internal combustion engine

Claim 1

A supercharged engine including a supercharger comprising a rotor having an axis of rotation and formed with a plurality of mutually separated, axially extending gas passages, and a casing supporting the rotor for rotation about the axis of rotation, the casing being formed with exhaust gas inlet port means opposing to an end of the rotor and exhaust gas outlet port means apposing to an end of the rotor, said exhaust gas outlet port means being offset with respect to the exhaust gas inlet port means in the direction of rotor rotation, said casing being formed, at an end of the rotor opposite to the end to which the exahust gas inlet port means is opposing, with intake gas inlet means and, at an end of the rotor opposite to the end to which the exhaust gas outlet port means is opposing, with intake gas inlet port means, said exhausg gas inlet port means being connected with exhaust port means of the engine, said intake gas outlet port means being connected with intake port means of the engine, characterized by electric motor means for rotationally driving the rotor of the supercharger and electric control means for controlling the operation of the motor means, said control means including means for controlling the speed of the electric motor means so that the ratio of the speed of the motor means to the speed of the engine is changed in accordance with the engine operating condition.