Bent oscillator stimulated rotary ultrasonic motor and electric excitation mode thereof

Abstract

The invention discloses a bent oscillator stimulated rotary ultrasonic motor and an electric excitation mode thereof. The rotary ultrasonic motor comprises a stator assembly, a rotor assembly and a rotation shaft arranged along the axial direction of the stator assembly, wherein the stator assembly and the rotor assembly are coaxially arranged; the stator assembly comprises a metal ring body and four piezoelectric bent oscillators; the metal ring body comprises an upper circular ring; four connecting feet are evenly distributed on the circumferential direction of an upper circular ring and are correspondingly connected with the four piezoelectric bent oscillators one by one; the four piezoelectric bent oscillators are evenly distributed at 90 degrees in a rotating mode around the center shaft of the metal ring body; and meanwhile, the length direction of each piezoelectric bent oscillator is tangent with the circumferential direction of the upper circular ring. Therefore, according to the invention, the rotary ultrasonic motor can realize forward and reverse rotation motion, and has high-power output characteristic and an electric excitation mode. The bent oscillator stimulated rotary ultrasonic motor has the characteristics of stable performance, high output power, compact structure, single requirement on a ceramic chip and low processing and assembling requirement.

Description

technical field [0001] The invention relates to a rotating ultrasonic motor excited by bending oscillators and its electric excitation mode, belonging to the field of ultrasonic motors. Background technique [0002] Ultrasonic motor is a new type of actuator that uses the inverse piezoelectric effect of piezoelectric ceramics to excite ultrasonic vibrations and is driven by friction. The rotary ultrasonic motor is a kind of ultrasonic motor. Compared with traditional electromagnetic motors, ultrasonic motors have the advantages of large torque-to-mass ratio, fast response, precise positioning, and no electromagnetic interference. They have broad application prospects in the fields of biomedicine, precision drives, optical devices, and aerospace. [0003] Searching the existing in-plane traveling wave rotary ultrasonic motor patents found that there are two main ways to realize in-plane traveling waves: excitation by patch piezoelectric ceramics and excitation by sandwich vi...

AI Technical Summary

Problems solved by technology

The application number is 200910212678.5, which discloses an in-plane traveling wave rotating ultrasonic motor, which uses a vibrator coupled with two modes of longitudinal and bending to excite the in-plane bending traveling wave motion of the ring. The advantages of this motor structure are simple structure and good processability. However, the normal layout of the vibrator is not conducive to the miniaturization of the motor, and the installation and clamping methods of the stator have a great influence on its vibration mode

The application number is 200910072818.3, which discloses a longitudinal-bending composite cylindrical rotating ultrasonic motor, which also uses a sandwich transducer with a longitudinal-bending composite mode to excite the in-plane traveling wave motion of the cylinder. The tangential position of the motor is connected with the cylinder by using two cantilever structures. The advantage of this motor is that it has a compact structure, but the machining accuracy and assembly requirements for the cantilever parts are relatively high.

In addition, the design of a single vibrator coupling two special-shaped modes is more complicated, requiring the use of different types of ceramic chips, and it is difficult for the two modes to achieve the same amplitude under the same excitation

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