Hybrid vehicle system

An improved hybrid system for a vehicle that includes an engine having an output shaft, a transmission device for changing the speed of rotation of an input shaft thereof and transmitting said rotation to vehicle wheels via an output shaft thereof, a clutch for engaging/disengaging the output shaft of the engine with/from the input shaft of the transmission device, a rotational electric device serving as an electric motor and an electric generator, a power transmission mechanism for coupling an input/output shaft of the rotational electric device with the input shaft of the transmission device, and an accumulator element for accumulating electrical power supplied by the rotational electric device, wherein the improvement comprises:

• means for determining gear change instructions for the transmission device;
• means for disengaging the clutch when a gear change instruction is determined;
• and
• means for controlling rotation of said rotational electric device, transmitted to the input shaft of said transmission device and geared down by said power transmission mechanism, in such a manner that the rotational speed of the input shaft of the transmission device assumes a target rotational speed required for the gear changing operation.