Disclosed herein is a microelectromechanical (MEMS) device, including a rotor and a first piezoelectric actuator mechanically coupled to the rotor. The first piezoelectric actuator is electrically coupled between a first signal node and a common voltage node. A second piezoelectric actuator is mechanically coupled to the rotor, and is electrically coupled between a second signal node and the common voltage node. Control circuitry includes a drive circuit configured to drive the first and second piezoelectric actuators, a sense circuit configured to process sense signals generated by the first and second pizeoelectric actuators, and a multiplexing circuit. The multiplexing circuit is configured to alternate between connecting the drive circuit to the first piezoelectric actuator while connecting the sense circuit to the second piezoelectric actuator, and connecting the drive circuit to the second piezoelectric actuator while connecting the sense circuit to the first piezoelectric actuator.

A vibration driving device that improves controllability in low speed driving. The vibration driving device includes a vibration actuator that includes a vibrator that has an elastic member and an electro-mechanical energy conversion element, a contact member that contacts the vibrator, and a control device that controls drive of the vibration actuator. The control device includes a speed detection unit that detects speed information showing relative speed of the vibrator and the contact member, and an adjustment unit that decreases amplitude of vibration excited in the vibrator in a case where the speed detection unit detects that a state where the vibration actuator does not operate approximately and a state where the vibration actuator operates at a speed faster than a target driving speed occur alternately after starting to drive the vibration actuator.

A piezoelectric driving device includes a piezoelectric vibrating body and a driving circuit. The piezoelectric vibrating body includes a contact which extends in a first direction and comes into contact with a driven member, a first piezoelectric element which generates bending vibration in a direction intersecting with the first direction in accordance with a first driving voltage, and a second piezoelectric element which generates longitudinal vibration in the first direction in accordance with a second driving voltage. The piezoelectric vibrating body is configured such that a resonance frequency of the longitudinal vibration is higher than a resonance frequency of the bending vibration. The driving circuit sets a driving frequency of each of the first driving voltage and the second driving voltage to be equal to or higher than the resonance frequency of the longitudinal vibration.

A piezoelectric drive device includes two vibrators having vibrating portions with piezoelectric elements and transmitting portions placed in the vibrating portions and transmitting drive forces to a driven member (e.g. a slider), and a fixing portion having through holes (first through hole, second through hole)into which pins or screws are inserted. The two vibrators are placed adjoiningly along a drive direction of the slider, and the fixing portion is placed between the two vibrators and fixing the two vibrators.

There is provided a control method for a piezoelectric driving device including a vibrating body including a piezoelectric element for driving and configured to vibrate when a driving signal is applied to the piezoelectric element for driving, a section to be driven that is driven by the vibration of the vibrating body, and a driving-signal generating section configured to generate the driving signal using a pulse signal generated based on a target pulse duty ratio. When the target pulse duty ratio is smaller than a predetermined value, the driving signal generated by the driving-signal generating section is an intermittently generated periodic signal.

A vibratory actuator includes a vibration member, a contact member, and a pressure member. The vibration member includes an elastic member, having protrusions. The contact member is in contact with the elastic member and moves in a direction relative to the vibration member. The pressure member pressurizes the vibration member and the contact member. Each of the protrusions includes a first contact surface in contact with the contact member. The contact member has a second contact surface made of metal sintered material and in contact with the vibration member. A ratio of a maximum amount of depression on the second contact surface in the direction of pressurization by the pressure member to a width of the first contact surface in a direction perpendicular to the direction of movement of the contact member relative to the vibration member and the direction of pressurization by the pressure member is 0.05% or less.

The invention relates to a rotation actuating device (1), comprising a base (2), a rotor (3) and at least two groups (40, 42) of drive units, each group comprising at least two drive units (4), wherein the drive units (4) are arranged peripherally on the base (2) and between the base and the rotor (3), wherein each drive unit (4) comprises two deflectable actors (5), which are arranged in a V-shape with respect to each other, and a friction element (6), which is connected to both actors, and wherein the rotor (3) and the friction elements (6) are pressed in a direction toward each other by means of a spring device (30) arranged between the drive units (4), such that, when the actors (5) are not deflected, all the friction elements (6) are in contact with the rotor (3) and jointly span a contact plane (K), wherein a continuous movement of the rotor (3) is realized by means of phase-offset control of the actors (5) of different groups (40, 42) of drive units (4). The invention further relates to a method for operating the rotation actuating device

A contact member that makes it possible to reduce variations in characteristics of individual vibration actuators. The contact member is in contact with a vibration member. The contact member has a sintered body of metal powder as a base material. A contact surface of the sintered body, which is in contact with the vibration member, is formed by impregnated resin portions as pore portions of the sintered body in which resin has been impregnated, and non-impregnated as pore portions of the sintered body in which the resin has been impregnated. A ratio of the impregnated resin portions with respect to an entirety of the contact surface is 2% or more and 15% or less, and a ratio of the non-impregnated pore portions with respect to the entirety of the contact surface is 3% or more.

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.

The invention relates to an annular or hollow cylindrical ultrasonic actuator, on the end faces of which are arranged n≥2 friction elements, and on the outer peripheral surface of which are arranged 2n excitation electrodes, spaced apart from one another in each case by a separating gap, each of the friction elements being arranged in the region of a separating gap, wherein, between friction elements that are adjacent with respect to the periphery of the ultrasonic actuator and are located on different end faces, two excitation electrodes are arranged such that, when the ultrasonic actuator is electrically excited, the friction elements of both end faces simultaneously perform a movement which is suitable for driving an element to be driven to rotate in the same direction. The invention further relates to an ultrasonic motor having an ultrasonic actuator of this kind and having a holding device in which the ultrasonic actuator is inserted.