A composite motor having high-precision positioning, comprising: a housing (1), a rough positioning assembly, a hollow output shaft (2), a fine positioning assembly, a power switching apparatus and a controller (6). A stepper motor (3) in the rough positioning assembly is responsible for rough positioning of the composite motor, an annular travelling wave ultrasonic motor in the fine positioning assembly is responsible for tail end fine positioning of the composite motor, and the controller (6) implements power output switching between the annular travelling wave ultrasonic motor and the stepper motor (3). The composite motor effectively solves the problem that annular travelling wave ultrasonic motors which operate continuously for a long time have a short service life, and ensures high-precision positioning while also extending motor service life.

A vibration type actuator includes a vibration body, having an annular elastic body and an electro-mechanical energy conversion element, and includes a contact body having an annular shape. The contact body contacts the vibration body and relatively moves with regard to the vibration body. The contact body includes a base portion, a supporting portion that extends in an annular shape from the base portion in a radial direction of the contact body, and a friction member that is provided to the supporting portion, is a member different from the supporting portion, and is in contact with the vibration body. The friction member is connected to the supporting portion by a first surface extending along a central axis direction of the contact body and an annular second surface extending in the radial direction. The first surface includes a portion inclined with respect to the direction of the contact body central axis.

There is provided a vibration wave motor that includes a plurality of pressing parts separated by slits and can prevent an intervention member from protruding from the slits. The vibration wave motor includes a vibrator, a driven body configured to be brought into pressure contact with the vibrator and to move relative to the vibrator, a pressing member configured to move together with the driven body and to bring the driven body into pressure contact with the vibrator, and an intervention member intervening between the driven body and the pressing member, and configured to be pressed together with the driven body when the pressing member brings the driven body into pressure contact with the vibrator. The pressing member includes a plurality of pressing parts that is separated by slits and presses the intervention member. The intervention member is firmly fixed to the driven body.

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.

Provided are a barium titanate-based piezoelectric ceramics having satisfactory piezoelectric performance and a satisfactory mechanical quality factor (Q.sub.m), and a piezoelectric element using the same. Specifically provided are a piezoelectric ceramics, including: crystal particles; and a grain boundary between the crystal particles, in which the crystal particles each include barium titanate having a perovskite-type structure and manganese at 0.04% by mass or more and 0.20% by mass or less in terms of a metal with respect to the barium titanate, and the grain boundary includes at least one compound selected from the group consisting of Ba.sub.4Ti.sub.12O.sub.27 and Ba.sub.6Ti.sub.17O.sub.40, and a piezoelectric element using the same.

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.

One aspect of the invention relates to a vibration type drive device including: a mechanical energy application element; a resilient member provided with the mechanical energy application element; a driven member subjected to a relative displacement with respect to the resilient member due to a vibration excited by the resilient member, wherein the resilient member includes a conductive material, and does not constitute an electric closed loop.

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.

A piezoelectric material contains a main component containing a perovskite-type metal oxide represented by general formula (1), a first sub-component containing Mn, and a second sub-component containing Bi or Bi and Li. A Mn content relative to 100 parts by weight of the metal oxide is 0.500 parts by weight or less (including 0 parts by weight) in terms of metal, a Bi content relative to 100 parts by weight of the metal oxide is 0.042 parts by weight or more and 0.850 parts by weight or less in terms of metal, and a Li content relative to 100 parts by weight of the metal oxide is 0.028 parts by weight or less (including 0 parts by weight) in terms of metal:
(Ba.sub.1−x−yCa.sub.xSn.sub.y).sub.α(Ti.sub.1−zZr.sub.z)O.sub.3 (where 0.020≦x≦0.200, 0.020≦y≦0.200, 0≦z≦0.085, 0.986≦α≦1.100)  General formula (1).

A vibration type actuator providing a satisfactory actuator performance even when an increase in speed is achieved and having a contact spring. The actuator includes a vibrator equipped with an electrical-mechanical energy conversion element, an elastic member to which the electrical-mechanical energy conversion element is fixed, and a protrusion provided on the elastic member. The vibrator can generate an elliptic movement in the protrusion. A driven body is configured to come into contact with the protrusion and to make a relative movement with respect to the vibrator. The protrusion includes a contact portion having a contact surface contacting the driven body, a continuous side wall portion protruding with respect to one end surface of the elastic member and forming a hollow structure, and a connection portion connecting the contact portion and the side wall portion and exhibiting flexibility in a direction normal to the contact surface.