Power transmission device for vehicle

A power transmission device for a vehicle, comprising:

• an electric motor;
• and
• a torque converter connected to the electric motor and configured to transmit torque of the electric motor to an output member, wherein
• a characteristic line for the torque converter is determined based on a capacity coefficient of the torque converter and indicates torque of the torque converter relative to each rotational speed of the torque converter,
• a characteristic line for the electric motor indicates a maximum output torque of the electric motor relative to each rotational speed of the electric motor,
• a first range corresponds to a range that is equal to and greater than a base rotational speed of the electric motor and is equal to or less than a first average rotational speed, which is an average of the base rotational speed of the electric motor and a maximum rotational speed of the electric motor, and
• the capacity coefficient of the torque converter is such that the characteristic line for the torque converter intersects the characteristic line for the electric motor in the first range.