The present invention relates to the field of electromechanical equipment for use in the vehicular field. More specifically, it relates to a selector, doser and transmitter of torque and power between one or more engines and one or more final transmission shafts. Applied for example on a vehicle without a gearbox, the new mechanism allows for selection of the ratio between the speed of rotation of one or more driving sources (such as an internal combustion engine drive shaft) and the final transmission shaft. In a preferred configuration, this selection is controlled electronically, managing the broad scope of possibilities provided by the mechanical configuration of this mechanism to dose the torque and power and regulate the rpm of the driving sources, in a hybrid motorization system.