An engine (EG1) is connected to a motor (MG1) and is connected to an engine (EG2) through a clutch (C1), a drive shaft (65) is connected to the engine (EG2) through a clutch (C2), and a motor (MG2) is installed on the drive shaft (65). In a low speed such as in starting, the clutch (C2) is set to off, disconnecting the engine (EG2) from the drive shaft (65) to travel by power from the motor (MG2), and in an intermediate speed, the clutch (C2) is set to on to travel mainly by power from the engine (EG2) efficiently operated. This enhances energy efficiency. Further, since only two clutches are needed other than two engines and two motors, the construction is simple. |