A motor includes: a rotor including an undulated surface; a rod disposed about the rotor; and a coil disposed about the rod to induce shape changes in the rod, which in turn impart forces to the undulated surface to rotate the rotor.

A vibration actuator difficult to be affected by an external force. A vibration element is held by a shaft. A driven element is held in pressure contact with an elastic body, and a bearing member is joined to the driven element in a manner rotatable about the shaft as a rotational axis. Vibrations excited in the vibration element cause the vibration element and the driven element to rotate relative to each other about the shaft. In the driven element, a connecting portion connects between a main body and a gear provided outside the main body. The degree of freedom of the main body with respect to the bearing member is restricted in other directions than a direction of rotation thereof and a thrust direction of the shaft. The connecting portion has a lower flexural rigidity in a direction parallel to the rotational axis than the main body and the gear.

A piezoelectric motor assembly for producing rotary motion, according to the present invention, has a motor frame and a circular body rotatably mounted on the motor frame having a diameter, a thickness, and a circumferential outer surface. At least two piezoelectric motors are mounted on the motor frame in tangential engagement with the outer surface of the circular body. The at least two piezoelectric motors are biased against the outer surface, resulting in an unbalanced net force on the circular body.

Provided is a vibration actuator including: an electromechanical transduction member that transduces electric power to a mechanical vibration; a transmission member that transmits the vibration from the electromechanical transduction member as a driving force; and an abutting portion that abuts on the transmission member and moves relative to the transmission member in response to the driving force. One of the transmission member and the abutting portion includes pores in its surface contacting the abutting portion or the transmission member at an area occupancy of 2% or higher. In this vibration actuator, the average area of the pores may be 3 m.sup.2 or larger. The other of the transmission member and the abutting portion may include iron in its surface contacting the one.

A rotary piezoelectric motor (1), in particular for a timepiece, including a rotor (3) configured to rotate and actuate a mechanical device, and a stator (2) configured to rotate the rotor (3), the stator (2) including a piezoelectric actuator provided with a resonator (29) arranged to perform an oscillatory motion, and a fixed element (4). The resonator in a movable element (5) arranged at a distance from the fixed element (4) and connected to the fixed element (4), the piezoelectric actuator being configured to move the movable element (5) against the rotor (3) to make it rotate, the movement of the movable element (5) making the rotor (3) rotate in a first direction.

The apparatus disclosed herein includes a single X-shaped ultrasonic motor (X-USM) and robotic arm with a ball joint, with is an actuator that can generate high torque and precise positioning for three degree of freedom (3-DOF). In one implementation, the X-shaped USM disclosed herein includes a plurality of electrodes configured such that a bottom surface of each of the electrodes is attached to a bottom surface of another of the electrodes and a side surface of each of the electrodes is attached to a side surface of another of the electrodes, wherein each of the electrodes having notch in vicinity of a notch of the other electrodes such that the notches form an opening at the center of the motor device and wherein each of the electrodes are configured to be excited by electric signal

This application discloses a camera module including a bracket, where the bracket is provided with a groove; a drive member, where the drive member is disposed on a first side of the bracket; a transmission member, where the transmission member is disposed on an inner wall of the groove, and the transmission member is electrically connected to the drive member; and a lens module, where at least part of the lens module is disposed in the groove, the lens module is movably connected to the transmission member, and the transmission member is configured to drive the lens module to move.