A vibration-type actuator which downsizes a pressurizing mechanism for bringing a vibrating body and a driven body into pressure contact with each other and generates required pressurizing force. The vibrating body has an elastic body, an electro-mechanical energy conversion element, and at least one projecting portion. The driven body has a driven base material that is brought into pressure contact with the vibrating body, and a permanent magnet joined to the driven base material. The driven base material and the elastic body face each other across the permanent magnet in a thickness direction of the elastic body. The permanent magnet is magnetized in the thickness direction of the elastic body. A magnetic action of the permanent magnet on the elastic body and the driven base material brings the projecting portion and the driven base material into pressure contact with each other in the thickness direction of the elastic body.

A piezoelectric motor with improved efficiency and improved specific power is disclosed. The piezoelectric motor has two frictionally engaged components mounted in such a way that they can move relative to each other. One component is a piezoelectric element in the form of a rectangular plate with metal coatings on its main planar surfaces. This component defines electrodes, where either some or all of the electrodes have leads for connection to a source of alternating voltage. The piezoelectric element is pressed by either its peripheral surfaces or by some parts of its peripheral surfaces at least by one of its sides or a section of one of its side against a cylindrical or planar surface of the other frictionally engaged component. The shape of the piezoelectric element, the arrangement and the number of the electrodes are configured to satisfy the condition of resonant excitation in the piezoelement of the first order mode of bending vibration along the length in the plane of the piezoelement during operation of the motor in one direction, and resonant excitation of the first order mode of longitudinal vibrations along the length during operation of the motor in the opposite direction.

A driving motor includes a member having a contact surface, a vibrator including a contact part that is brought into contact with the contact surface, a pressing unit, and a contact member located between the pressing unit and the vibrator. The vibrator and the member move relatively by a vibration of the vibrator. The pressing unit comprises an elastic member so as to apply a pressing force on the contact part against the member including the contact surface. The contact member has a curved surface portion formed as an arc shape curved toward the pressing unit, and comes into contact with the pressing unit at the curved surface portion. The curved surface portion is formed so as to locate a position of a center of a circle including the arc shape of the curved surface portion not closer to the contact member than to the contact part.

An ultrasonic motor includes a vibrator including a contact surface that is brought into contact with a member to be driven, and a piezoelectric element fixed thereto, the vibrator configured to drive the member to be driven by an ultrasonic vibration excited by the piezoelectric element; a fixing unit; and a pressing member supported by a restraining part of the fixing unit so as not to move in a direction parallel to the contact surface, the pressing member configured to apply a bias force to the vibrator so as to press the contact surface against the member to be driven.

A method of driving a vibration actuator. The vibration actuator includes a vibration element including a piezoelectric element as an electromechanical energy conversion element and an elastic body which is joined to the piezoelectric element, and a driven element which is brought into pressure contact with the elastic body. Driving vibration is excited in the vibration element by applying a drive signal to the piezoelectric element, whereby the vibration element and the driven element are moved relative to each other. The driving vibration is vibration in which at least n-th-order vibration and 2n-th-order vibration are combined, n being a natural number.

A vibration type driving device includes a vibrator configured to make an elliptic motion of a contact portion by combining vibrations in different vibration modes, and a driven body configured to be rotated relative to the vibrator by the elliptic motion while being in contact with the contact portion. A contact pressure of the contact portion with the driven body is lower on a radial inner side than on a radial outer side in a radial direction of the rotation.

A vibration actuator reduced in the manufacturing cost and size thereof without using a magnet. An elastic body of a vibration element includes a base portion joined to an electromechanical energy conversion element, and a pair of contact portions extending from said base portion. The contact portions are brought into pressure contact with a driven element, by elastic deformation, in a third direction orthogonal to both of a first direction of relative motion of the vibration element and the driven element and a second direction as a thickness direction of the conversion element. When driving vibration is excited in the vibration element by applying a predetermined AC voltage to said conversion element, the contact portions apply frictional driving forces to the driven element, for moving the vibration element and the driven element relative to each other in the first direction.

A vibration type driving apparatus including: a vibrator including an electro-mechanical energy conversion device; a driven body between the vibrator and a movable body and driven in a first direction by the vibrator; and a moving mechanism that allows the movable body to move in a second direction relative to the driven body, in which the second direction is a direction intersecting the first direction in a plane parallel to a plane where the vibrator and the driven body are in contact with each other.

The actuator includes a vibration plate including a fixing portion for fixing the vibration plate to a holding member, and a connection portion for connecting a center portion and the fixing portion, and is provided between a surface and a friction-sliding surface in a direction in which the vibration plate is pressed against the rotor by a pressurizing force produced by a pressure member. When finishing a surface on which a piezoelectric device is to be fixed to the vibration plate to a uniform surface by polishing, a decrease in the performance of the ultrasonic motor due to deformation of the vibration plate that is caused by warping of support portions that extend from both ends thereof or by burrs or the like can be prevented, and the time required to polish the vibration plate can be reduced.

A vibration-type actuator that is capable of reducing an unnecessary vibration during driving. A vibration body is configured by connecting an electro-mechanical energy conversion element and an elastic body. A driven body is in pressure contact with the vibration body. A controller moves the vibration body and the driven body relatively by a vibration that is excited in the vibration body by applying driving voltage to the electro-mechanical energy conversion element so that a difference between a resonance frequency in a natural vibration mode of the vibration body that is higher than an upper limit frequency of a predetermined driving frequency range and that is nearest to the upper limit frequency and a frequency of the driving voltage is larger than a difference between a resonance frequency in a natural vibration mode used for moving the vibration body and the driven body relatively and the frequency of the driving voltage.