Throttle valve assembly

Throttle valve assembly (10) comprising: - a valve housing (40) having a main channel (32) and an auxiliary channel (36), - a main throttle valve (34) pivotally mounted in the main channel (32), - an auxiliary throttle valve (38) pivotally mounted in the auxiliary channel (36), - a common rotating actuator (54) controlling the opening angle of both the main throttle valve (34) and the auxiliary throttle valve (38) through an actuating mechanism (52), characterized by said actuating mechanism (52) comprising a crank mechanism (70) connected between the auxiliary pivoting shaft (50) and a gear train (58) driven by the rotating actuator (54).