A dynamoelectric machine main body that includes: a housing that is constituted by a rear bracket and a front bracket; a rotor; a stator; and a fan, and a power supply unit that is mounted integrally onto the dynamoelectric machine main body are included, the power supply unit is disposed between the fan and a bottom portion of the rear bracket, and the power supply unit is disposed between the fan and a bottom portion of the rear bracket, and the rear bracket has: air discharge ports that are formed on portions that are positioned radially outside the fan; and air suction ports that have openings nearer to a bottom portion than the power supply unit, and includes a partitioning member for configuring a ventilation channel that extends from the air suction ports to the air discharge ports that is disposed between the power supply unit and the fan.