National Science Council of Republic of China

Kingstate Electronics Corporation

Fuh-Liang Wen

Minsun Ouyang

A kind of piezoceramic shaft-driving type ultrasonic motor is a piezoelectric disc device as the driving stator of the motor in which the A.C power is supplied to form extend-contract motion of piezoceramic based on converse piezoelectric effect. The flexural wave of back plate is generated by push-pull force of piezoceramic oscillation. By utilizing the pin head above the stator as the dynamic shaft bearing wherein the rotor being drive is connected directly on the bearing to transmit the power with friction contact force. The rotating speed of the prototype motor could be reached as high as 3000 rpm on the driving condition of 74 kHz, voltage &plus;/&minus;10Vpp, and 0.2 A current, wherein the torque is about 0.003 N&middot;m. It could be utilized in the driver of CD, the actuator in the biomedical engineering, or the cooling fan in the computer CPU.

Piezoceramic shaft-driving type ultrasonic motor

A thin-disc piezoelectric actuating ultrasonic motor includes a stator made up of a commercially available piezoelectric element that includes a piezoelectric ceramic membrane bonded on a metal plate to form a concentric disk. An ultrasonic motor driving mechanism induces mechanical vibration in the piezoelectric element by extension and shrinkage of the metal back plate, upon application of single phase AC power. There are two propagating directions in the induced mechanical vibrating wave. One is a radial component, and the other is a transverse component. The outer edge of the piezoelectric element thus forms traveling waves in different directions. These traveling waves may be used to provide a torque so as to drive the rotor to rotate.

Growing community of inventors

Hsinchu Hsien, Taiwan

Fuh-Liang Wen