The present invention relates to an ultrasonic motor comprising a stator
formed by using an acoustic waveguide of helical coil shape or an
acoustic waveguide of in-plane spiral coil shape, so that a rotor placed
in close proximity to, or in close contact with the coil is rotated,
traveled, or performed curved line movement by the propagation of the
wave on the stator, thereby eliminating the provision of a preload spring
and an absorber, simplifying the structure of the motor, reducing the
size of the motor, and enabling to work in a liquid environment without
water proofing and rotation of a hollow tube.