A vibration-type actuator capable of suppressing reduction in holding torque or holding force under influence of humidity. A vibration-type actuator 10 includes a vibrating body 2 and a driven body 1. The vibrating body 2 has a piezoelectric element 2c and an elastic body 2b. The driven body 1 is in contact with the vibrating body 2. The vibration-type actuator 10 moves the vibrating body 2 and the driven body 1 relatively to each other by vibration excited to the vibrating body 2. At least one of a first contact portion of the vibrating body 2 and a second contact portion of the driven body 1 includes a stainless-steel sintered body with pores and at least some of the pores are impregnated with a resin.

A vibration type actuator includes a vibrating body including an elastic body and an electro-mechanical energy conversion element, a contact body contacting the vibrating body, a flexible printed board provided with a concave portion on a surface opposite to a surface contacting the electro-mechanical energy conversion element and configured to supply electric power to the electro-mechanical energy conversion element, and a holding member provided with a projection portion engaging with the concave portion.

A vibration actuator capable of reducing variations of pressure force and reaction force acting on a vibrator and a contact member has a specific construction. Vibrator devices respectively have vibrators, each of which includes an elastic member and an electro-mechanical energy conversion element. A contact member contacts the vibrators and is movable in a predetermined direction relatively to the vibrators. A restraint member fixes a first vibrator device among the vibrator devices to restrict a degree of freedom in the predetermined direction. A flexible member connects a second vibrator device among the vibrator devices to the first vibrator device. The flexible member has predetermined rigidity in the predetermined direction and has rigidity, which is lower than the predetermined rigidity, in directions other than the predetermined direction.

A vibration-type actuator includes a vibrator, a contact member, a ball, and a base table having a third guide. The vibrator has an elastic member and an energy conversion element. The contact member is fixed to the base table, contacts the elastic member, and extends in a predetermined direction. The vibrator and the contact member are driven along the predetermined direction due to a vibration generated by a voltage applied to the energy conversion element. A first guide provided on the contact member extends in the predetermined direction and a second guide that is connected with the vibrator faces the first guide and moves integrally with the vibrator. The ball is held between the first guide and the second guide rollably in the predetermined direction. The second guide extends in the predetermined direction and includes a fitting projection portion loosely fitted to a groove portion provided on the third guide.

A piezoelectric drive unit is configured for driving a passive element relative to an active element, wherein the active element includes a resonator with two arms, each extending in parallel to a reference plane and ending in a contact element, which is movable by oscillating movements of the arms and thereby drives the passive element. Each of the arms has, at the outer end of the arm, a protrusion extending inward, toward the other arm, and on at least one of the arms, the respective contact element, arranged at the arm's outer end, extends outward, away from the other arm.

A controller is capable of reducing time required to stop a control target at a target stop position as a final stop position. The controller drives a vibration element including a piezoelectric element by an AC signal to thereby move a contact body, in contact with the vibration element, relative to the vibration element. The controller controls a pulse duty cycle of a signal converted to the AC signal based on a difference between a target stop position, which is a final stop position of the contact body, and a current position of the contact body, and an actual speed of the contact body.

Provided is a vibration wave motor including: a vibrator; a pressurizing member configured to pressurize the vibrator against a friction member; a holding member configured to hold the vibrator; and a buffering member provided between the vibrator and the holding member. The vibrator and the friction member are moved relatively to each other in a relative movement direction by vibration of the vibrator, and the holding member holds the vibrator in such a manner that an extending part extending in a pressurizing direction of the pressurizing member sandwiches the vibrator and the buffering member.

Provided is a control apparatus of a vibration-type actuator for generating an elliptical motion of contact portions by a common alternating current including a frequency determining unit for setting a frequency of the alternating current. The frequency determining unit sets the frequency of the alternating current for changing an ellipticity of the elliptical motion, within a frequency range such that ellipticity changing frequency ranges set for the vibrators are overlapped, and the ellipticity changing frequency ranges are set for the vibrators as frequency ranges between an upper limit and a lower limit, such that the lower limit is a maximum resonant frequency at a time of changing the ellipticity, and the upper limit is larger than the lower limit and is a maximum frequency for the relative movement of the driving member.

A control apparatus for a vibration type actuator that moves a vibrating body in which vibrations are excited by an electromechanical energy conversion element, and a contact body contacting the vibrating body relative to each other includes a generation unit configured to generate multi-phase driving signals having a phase difference applied to the electromechanical energy conversion element, and a detection unit configured to detect an actual position of a movable unit including the vibrating body or the contact body. The generation unit sets the phase difference based on a deviation of the actual position from a target position of the movable unit. The generation unit makes larger a change rate of the phase difference against the deviation from when the movable unit stops to when the movable unit starts moving as the target position changes than that after the movable unit starts moving.

A vibration-type actuator capable of suppressing reduction in holding torque or holding force under influence of humidity. A vibration-type actuator 10 includes a vibrating body 2 and a driven body 1. The vibrating body 2 has a piezoelectric element 2c and an elastic body 2b. The driven body 1 is in contact with the vibrating body 2. The vibration-type actuator 10 moves the vibrating body 2 and the driven body 1 relatively to each other by vibration excited to the vibrating body 2. At least one of a first contact portion of the vibrating body 2 and a second contact portion of the driven body 1 includes a stainless-steel sintered body with pores and at least some of the pores are impregnated with a resin.