PURPOSE: An ultrasonic motor is provided to obtain twice torque by vibrating a rotor at both sides in the same direction and overlapping the torques which are generated from the both sides. CONSTITUTION: A rotor(20) is installed inside a motor casing(10). A stator comprises a rotary shaft penetrating through the motor casing. A first rotor(30) is arranged inside the motor casing and is contacted with the upper part of the rotor. A piezoelectric material(40) generates vibration by supplying the AC power source thereto. A second stator(50) is arranged inside the motor casing and is contacted with the lower part of the rotor. A second piezoelectric material(60) is arranged inside the motor casing and is contact with the upper part of the second stator.
