Patent attributes
An assist generator motor is driven by an engine to generate power or assists in a drive of the engine by supply of power from an electricity storage device. A revolving electric motor is driven by power supplied from the electricity storage device or supplies regeneration power generated by a regeneration operation to the electricity storage device. The assist generator motor is controlled by a first inverter. The revolving electric motor is controlled by a second inverter. The first inverter and the second inverter are mounted on a support bracket elastically supported on a revolving frame in a position different from a position where the electricity storage device is mounted.