<p>This vibration actuator rotates a rotor using ultrasonic vibrations generated at a stator, and a pre-load member imparts a contact pressure of 30 MPa between the rotor and stator. Also, a supply body impregnated with oil is provided within a concavity of the stator, and the contact section between the rotor and stator is lubricated by means of the oil supplied from the supply body. A fluorine-based oil having a kinematic viscosity at 40°C of VG400 in the ISO viscosity classification is selected as the oil impregnating the supply body.</p>
