US Patent 11207969 Hybrid powertrain for vehicles

A hybrid powertrain may include an engine input shaft connected to an engine by a main clutch, a motor input shaft mounted coaxially with the engine input shaft and connected to a motor, a center synchronizer installed to interrupt connection between the engine input shaft and the motor input shaft, first and second output shafts mounted parallel to the engine input shaft, a variable driving gear provided on the motor input shaft to maintain or increase a rotation speed of the motor input shaft and then to transmit the maintained or increased rotation speed to the first output shaft, and plural external gear pairs installed to form different transmission gear ratios between the engine input shaft and the first output shaft and between the engine input shaft and the second output shaft.