Rotary ultrasonic motor based on piezoelectric single crystal surface-cut mode

Abstract

The invention discloses a rotary ultrasonic motor based on a piezoelectric single crystal surface-cut mode. The rotary ultrasonic motor is formed by a stator assembly and a rotator assembly. The stator assembly comprises vibrators, a stator support, and a stator base. The shape of the vibrator is square flat plate shape. The upper surface and the lower surface of the vibrator are plated with electrodes. The lower surfaces of the vibrators are on a same plane. The plane is vertical to a motor rotating axis. The middle points of the lower surfaces are connected to form a regular polygon. The motor rotating axis passes the middle point of the regular polygon. Through controlling excitation modes of a piezoelectric vibrator, a surface-cut mode is excited, and the rotator is driven to rotate along the periphery through driving feet. Compared with a travelling wave rotary ultrasonic motor which is most widely used, the ultrasonic motor is simple in structure, and output torque is doubled, power density is doubled, electromechanical coupling efficiency is 2.8 times higher (about 0.6), driving voltage is 40-200 times lower, temperature rise is more than 10 DEG lower, and the thickness of the motor is just one third of that of an existing travelling wave ultrasonic motor. The rotary ultrasonic motor is especially suitable for application occasions of precision driving and biomedical engineering.

Description

technical field [0001] The invention relates to an ultrasonic motor, in particular to a rotating ultrasonic motor based on a piezoelectric single-crystal face-cut mode, and belongs to the technical field of mechatronics. Background technique [0002] Compared with traditional electromagnetic motors, ultrasonic motors can directly output large torque at low speeds, and have fast transient response, high positioning accuracy, high power density, no electromagnetic interference, no deceleration mechanism, and no rectifier circuit and structure at the receiving end of wireless power supply. Simple, flexible design form, easy miniaturization and other advantages, it has broad application prospects in aerospace, robotics, medical equipment, precision instruments, automobile industry and other fields. [0003] After searching the literature of the prior art, it is found that the piezoelectric materials used in the existing rotary ultrasonic motors are mainly lead zirconate titanate...

AI Technical Summary

Problems solved by technology

Its shortcomings are: low electromechanical coupling coefficient, low power density, excitation voltage (normal working electric field 800 ~ 1000V p / mm) high and temperature rise, the thickness of the motor is nearly 30mm, etc.

These two motors are essentially k t Thickness mode, the disadvantages are: high excitation voltage, low electromechanical coupling coefficient (only 0.20~0.23), complex motor structure, thickness 40~60mm, too large volume and weight and low power density, it is difficult to make a compact micro motor

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