Abstract: A vibration actuator includes an elastic member and a relative movement member. The elastic member generates oscillatory waves by oscillation of an electromechanical conversion element. The relative movement member with which the elastic member is in pressure contact is driven by the oscillatory waves to rotationally move with respect to the elastic member. Of the elastic member and the relative movement member, at least one member has a plurality of spaces at one contacting face opposite to the other contacting face of the other member. The spaces are filled with friction coefficient adjusting substances so that a coefficient of friction of the one contacting face of the one member changes in a radial direction.

Abstract: A vibration actuator includes an elastic member and a relative movement member. The elastic member generates oscillatory waves by oscillation of an electromechanical conversion element. The relative movement member with which the elastic member is in pressure contact is driven by the oscillatory waves to rotationally move with respect to the elastic member. Of the elastic member and the relative movement member, at least one member has a plurality of spaces at one contacting face opposite to the other contacting face of the other member. The spaces are filled with friction coefficient adjusting substances so that a coefficient of friction of the one contacting face of the one member changes in a radial direction.

Abstract: A vibrational actuator includes an oscillator that generates vibrational energy; a mover that is rotationally driven around a first axis by the vibrational energy; an output shaft that rotates around a second axis by using a rotational force communicated from the mover; and a flange portion projecting out from the output shaft along a direction intersecting the second axis, that rotates together with the output shaft. Pressure is applied to the mover at a position between the flange portion and the oscillator. A distance from the first axis to an outer portion of the mover over an area where the mover is pressed against the flange portion is set to a value large enough to prevent the first axis and the second axis from becoming tilted relative to each other.

Abstract: A vibrational actuator includes an oscillator that generates vibrational energy; a mover that is rotationally driven around a first axis by the vibrational energy; an output shaft that rotates around a second axis by using a rotational force communicated from the mover; and a flange portion projecting out from the output shaft along a direction intersecting the second axis, that rotates together with the output shaft. Pressure is applied to the mover at a position between the flange portion and the oscillator. A distance from the first axis to an outer portion of the mover over an area where the mover is pressed against the flange portion is set to a value large enough to prevent the first axis and the second axis from becoming tilted relative to each other.