A PMDC motor includes a housing, a stator magnet fixed to the inner circumferential surface of the housing, a rotor core received in the housing and facing the stator magnet, and rotor windings wound around the rotor core. The rotor core includes a plurality of rotor teeth, each of the rotor teeth including a tooth body and a tooth tip. A ratio of the outer diameter of the rotor core to an outer diameter of the housing is in the range of 0.6 to 0.67. Compared to the existing PMDC motor, the PMDC motor of the present invention can satisfy the same performance requirement, while reducing the size and weight of the rotor core and hence the weight of the rotor windings. In this way, the total weight and hence the moment of inertia of the rotor is reduced, thereby effectively reducing the noise generated during operation of the motor.