A linear piezoelectric motor including a passive element having an elongated shape, and a piezoelectric actuator including a resonator including a pair of arms connected at one of their ends at a connection zone, the two other ends being called free, the passive element being capable of being moved linearly between the free ends by friction of the free ends against the passive element, the passive element and the resonator being inclined with respect to one another by a non-zero angle (α) of less than 90 degrees.

An ultrasonic actuator with increased radiating surface is presented. The increased radiating surface is provided by a plurality of piezoelectric stacks that are each compressed by action of a respective bolt against a common backing structure of the actuator. According to one aspect, each of the stacks includes a plurality of stacked piezoelectric rings with the respective bolt arranged through the central opening of the rings. According to another aspect, one or both of the backing structure and the horn of the actuator include tuning grooves and/or tuning slots to produce amplitude uniformity of displacement through the actuator. According to another aspect, the radiating surface has a symmetrical shape about an axial direction of the actuator with a lateral dimension that is in a range between one quarter and one half of the wavelength of operation of the actuator.

An ultrasonic device according to an aspect of the present disclosure includes a substrate in which an opening section piercing through the substrate in a thickness direction is provided, a vibration plate provided on the substrate to close the opening section, a piezoelectric element provided in a position corresponding to the opening section on a first surface at the opposite side of the substrate side of the vibration plate, and an elastic layer provided in contact with a second surface at the substrate side of the vibration plate at the inner side of the opening section of the substrate. The elastic layer includes a curved surface recessed to the vibration plate side at the opposite side of the vibration plate side.

There are provided a laminated piezoelectric element in which a stress applied to an interface between a cover layer and a stacked body is reduced, and an injection device and a fuel injection system provided with the laminated piezoelectric element. A laminated piezoelectric element includes a stacked body in which piezoelectric layers and internal electrode layers are alternately laminated; and a cover layer disposed so as to surround a side face of the stacked body, and the cover layer has a two-layer structure with an annular boundary when viewed in a section perpendicular to a stacking direction of the stacked body.

A driving device generates a driving signal and outputs the driving signal to a piezoelectric element, the driving signal having a waveform obtained by using, as a first modulated wave, a first low-frequency wave having a frequency of 1 Hz or more and less than 100 Hz, using, as a second modulated wave, a waveform obtained by modulating an amplitude of a second low-frequency wave having a frequency of 100 Hz or more and 300 Hz or less with the first modulated wave, and modulating a high-frequency wave having a frequency of 20 kHz or more and 100 kHz or less with the second modulated wave.

A method for manufacturing a shaker device using 3D-printing (i.e., additive manufacturing). An electromagnet is formed by producing a bobbin body and winding an electrical conductor on the bobbin body to form an electromagnet coil. A cylindrical body is 3D-printed and the bobbin body with the electromagnet coil is coupled within an interior of the cylindrical body. A piston assembly is then positioned within the bobbin assembly. The shaker device is operated by controllably applying a magnetic field through the electromagnet coil that impinges a permanent magnet of the piston assembly to cause movement of the cylindrical body relative to the piston. By using these 3D printing techniques, the composition of materials can be varied within a single component part, fine structural details can be included in the components, and components can be 3D printed directly on each other to eliminate tolerance issues relating to small variations in component size.

A driving-unit operation method includes: generating pulse blocks on the basis of driving pulses; and modifying a driving signal in accordance with a position error signal. In the modifying the driving signal, when the position error signal is in a first range, the shape of the driving pulses is modified so as to form a first driving-pulse shape, and the pulse-block duty cycle is set to a first pulse-block duty cycle value, whereas when the position error signal is in a second range, the shape of the driving pulses is modified so as to form a second driving-pulse shape, and the pulse-block duty cycle is set to a second pulse-block duty cycle value.

A lens drive device is provided with: a lens holder for holding a lens; an ultrasonic motor configured to move the lens holder in a direction of an optical axis; and a support part configured to support the lens holder in a state where the lens holder is urged in a direction orthogonal to the optical axis and such that the lens holder is capable of moving in the direction of the optical axis. The support part includes two pairs of support portions which are disposed respectively on two straight lines along an urging direction and parallel to each other such that the support portions of each pair holds the lend holder therebetween.

A touchpad module includes a touch member, a bracket, a piezoelectric vibration unit and an elastic element. The bracket is located under the touch member. A portion of the touch member is exposed to a first perforation of the bracket. The piezoelectric vibration unit is aligned with the first perforation of the bracket. The piezoelectric vibration unit has a first surface and a second surface, which are opposed to each other. The elastic element installed on the bracket and contacted with the second surface of the piezoelectric vibration unit. When the piezoelectric vibration unit vibrates, a first reaction force is generated between the first surface of the piezoelectric vibration unit and the portion of the touch member exposed to the first perforation, and a second reaction force is generated between the second surface of the piezoelectric vibration unit and the elastic element.

A wheel hub assembly for motor vehicles, having a rotatable hub, a bearing unit in turn comprising a radially outer ring, a radially inner ring and a plurality of rolling bodies. The axial interface between the wheel hub assembly and a knuckle of a motor vehicle suspension provides at least one piezoelectric spacer configured to detect first mechanical vibrations coming from the components of the wheel hub assembly and to implement corrective action consisting of second mechanical vibrations of almost equal amplitude but with opposite direction and phase, so that the resultant of the first and second mechanical vibrations is close to zero.