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.

An ultrasonic motor includes a vibration section having a piezoelectric element configured to generate vibration by receiving a drive voltage, a driven section, a convex section connected to the vibration section and configured to transmit vibration of the vibration section to the driven section, a drive circuit configured to generate the drive voltage, an encoder configured to detect a movement amount of the driven section, a storage section configured to store a specified voltage value, and a determination section configured to receive position information from the encoder when the driven section starts to move and a voltage value at the time of start up from the drive circuit and to determine that least one of the convex section or the driven section is worn out when the voltage value at the time of start up is larger than the specified voltage value.

A drive control circuit restores a holding force when a vibrator and a driven body have been left at a standstill for a long time period and when they are used in a high-humidity environment. A drive circuit outputs an alternating-current signal, which is to be applied to an electro-mechanical energy conversion element, based on an output from a control unit. The control circuit controls the drive circuit with first timing such that elliptical motion produced in the vibrator takes a path of which a component parallel to a driving direction of the driven body is large as compared to such a path that a speed at which the driven body is driven is the maximum. The first timing is different from second timing with which relative positions of the vibrator and the driven body are changed.

A vibration driving device that achieves low cost and high accuracy while reducing driving load. A drive unit has a vibrator with a projection and generates driving force by vibrating the vibrator. A first unit has a contact portion with which the projection is in pressure contact in a first direction. A second unit rotates relative to the first unit around a rotation axis parallel to the first direction by the driving force. Three or more support members are between the first and second units in the first direction to support the first and second units rotatably. The support members are positioned such that, during relative rotation of the first and second units, a contact point at which the projection contacts the contact portion is always located in at least one of triangular areas formed by connecting any three support members with straight lines when viewed in the first direction.

The invention relates to an ultrasonic motor having a bracket, a plate-shaped ultrasonic actuator arranged in the bracket, said ultrasonic actuator having two opposing main surfaces and at least four side surfaces connecting the main surfaces to one another, and an element to be driven, wherein the ultrasonic actuator is pressed against the element to be driven, and the bracket comprises a first frame that supports the ultrasonic actuator and a second frame in which the first frame is supported and guided by bearing elements, and the bearing elements are pressed elastically against the first frame by the second frame. According to the invention, the first frame is pressed against the main surfaces of the ultrasonic actuator via the bearing elements, thus preventing or reducing movements of the ultrasonic actuator in a direction vertical to the main surfaces.

An aspect of the present invention relates to a vibration element comprising: a substrate; a ceramic layer containing glass and provided on the substrate; and a piezoelectric element comprising an electrode layer fixed to the substrate with the ceramic layer therebetween and a piezoelectric layer, wherein the piezoelectric layer, the electrode layer, the substrate, and the ceramic layer are integrated by the piezoelectric layer, the electrode layer, the substrate, and the ceramic layer being sintered together at a sintering temperature of from 800° C. or higher to 940° C. or lower.

The present invention relates to a vibration-type driving apparatus including a vibrator including an electro-mechanical transducer; a driven body disposed in pressure-contact with the vibrator; a supporting portion extending from the vibrator; a base to which the vibrator is fixed with the supporting portion interposed therebetween; a vibration absorber disposed between the supporting portion and the base; and a compressive-force adjusting device capable of adjusting a compressive force to be applied to the vibration absorber between the supporting portion and the base.

Disclosed herein is a micro stage using a piezoelectric element that can be reliably operated even in a vacuum environment. In a particle column requiring a high precision, for example, a microelectronic column, the micro stage can be used as a stage with micro or nano degree precision for alignment of parts of the column, or for moving a sample, and so on.

There is disclosed an ultrasonic motor having a vibrator that vibrates by a high frequency drive voltage applied thereto, a sliding member that comes in contact frictionally with the vibrator, pressurizing means for pressurizing the vibrator to the sliding member, a base to which the vibrator is fixed, a vibrator support member holding the base, and coupling means for coupling the vibrator with the vibrator support member, the vibrator and the sliding member being relatively moved by the vibration, wherein the coupling means includes the base, the rolling member that freely moves the base to the vibrator support member in a pressurizing direction of the pressurizing means, and an urging member that urges the rolling member in a direction perpendicular to the pressurizing direction of the pressurizing means.

A piezoelectric drive device includes a piezoelectric drive portion which includes a contact portion capable of coming into contact with a driven body and a piezoelectric material, and a drive circuit which drives the piezoelectric drive portion. The drive circuit sets an allowable maximum output torque Tlim or less to an allowable output torque range, sets output torque Td of the piezoelectric drive portion so as to be within the allowable output torque range, and operates the piezoelectric drive portion. The allowable maximum output torque Tlim is expressed by the following Expression (1).
Tlim=r1×μk×Ns×fs  (1)
In the expression, r1 is a distance between a rotation center of the driven body and a contact position of the contact portion, μk is a dynamic friction coefficient between the driven body and the contact portion, Ns is a pressing force by which the contact portion presses the driven body when an operation of the piezoelectric drive portion stops, and fs is a coefficient of 1 or less.