A power transmission device, comprising: an input-side rotor configured to receive power transmitted from an engine, the input-side rotor including a rotor conductor for generating a rotating magnetic field when alternating current flows therethrough; a first output-side rotor configured to be rotatable relative to the input-side rotor and to transmit power to a drive shaft, torque acting between the first output-side rotor and the input-side rotor in response to exertion of the rotating magnetic field generated by the rotor conductor; a stator including a stator conductor for generating a rotating magnetic field when alternating current flows therethrough; a second output-side rotor configured to rotate with the first output-side rotor and transmit power to the drive shaft, torque acting between the second output-side rotor and the stator in response to exertion of the rotating magnetic field generated by the stator conductor; a slip ring electrically connected with the rotor conductor, the slip ring rotating with the input-side rotor; a brush configured to electrically contact the slip ring; the power transmission device being characterized in that a temperature obtaining section configured to obtain a temperature of either one of the brush and the slip ring; and a restriction mechanism for restricting rotation of the input-side rotor, wherein, the power transmitting device is configured so that, when driving the drive shaft with operation of the engine being stopped, the rotation of the input-side rotor is restricted by the restriction mechanism, and further, based on the temperature obtained by the temperature obtaining section, allocation is controlled between the torque acting between the input-side rotor and first output-side rotor by the alternating current of the rotor conductor with respect to a required torque of the drive shaft, and the torque acting between the stator and the second output-side rotor by the alternating current of the stator conductor with respect to the required torque of the drive shaft. an input-side rotor configured to receive power transmitted from an engine, the input-side rotor including a rotor conductor for generating a rotating magnetic field when alternating current flows therethrough; a first output-side rotor configured to be rotatable relative to the input-side rotor and to transmit power to a drive shaft, torque acting between the first output-side rotor and the input-side rotor in response to exertion of the rotating magnetic field generated by the rotor conductor; a stator including a stator conductor for generating a rotating magnetic field when alternating current flows therethrough; a second output-side rotor configured to rotate with the first output-side rotor and transmit power to the drive shaft, torque acting between the second output-side rotor and the stator in response to exertion of the rotating magnetic field generated by the stator conductor; a slip ring electrically connected with the rotor conductor, the slip ring rotating with the input-side rotor; a brush configured to electrically contact the slip ring; the power transmission device being characterized in that a temperature obtaining section configured to obtain a temperature of either one of the brush and the slip ring; and a restriction mechanism for restricting rotation of the input-side rotor, wherein, the power transmitting device is configured so that, when driving the drive shaft with operation of the engine being stopped, the rotation of the input-side rotor is restricted by the restriction mechanism, and further, based on the temperature obtained by the temperature obtaining section, allocation is controlled between the torque acting between the input-side rotor and first output-side rotor by the alternating current of the rotor conductor with respect to a required torque of the drive shaft, and the torque acting between the stator and the second output-side rotor by the alternating current of the stator conductor with respect to the required torque of the drive shaft.