Screw type ultrasonic motor utilizing multi-wavelength exciting mode

To increase the output force and improve the contact driving status between stator and output shaft of screw type ultrasonic motor, a cylindrical stator by attaching 12 PZT plates on a metal elastomer was presented. A traveling wave with the 3 wavelengths processing along the circumference of stator was excited to drive the screw output shaft. And a novel screw type ultrasonic motor utilizing the multi-wavelength exciting mode was proposed. The design of ultrasonic motor was given out. The exciting method of multi-wavelength exciting mode was clarified. A vibration mode simulation of stator was carried out by the finite element method. A prototype of screw type ultrasonic motor utilizing the multi-wavelength exciting mode was developed. The dimension of stator is 36 mm×30 mm×M24 mm (length×width×inner diameter). The testing results indicate that the prototype utilizing the multi-wavelength exciting mode can be driven availably. The output velocity and force increase linearly as the exciting voltage rises. A maximum output force 40 N can be obtained at a 52.1 kHz working frequency and an exciting voltage of effective value 42 V.