Tower-like ultrasonic motor with asymmetrical structure and asymmetrical modes thereof as well as electric excitation mode of asymmetrical modes

Abstract

The invention provides a tower-like ultrasonic motor with an asymmetrical structure and asymmetrical modes thereof as well as an electric excitation mode of the asymmetrical modes, belonging to ultrasonic motors. The tower-like ultrasonic motor comprises a stator and a linear guide rail, wherein the guide rail is pressed on a driving foot of the stator by pre-pressure; the stator is tower-like and comprises two piezoelectric vibrators with the different lengths, wherein the two piezoelectric vibrators form an included angle; each piezoelectric vibrator comprises a back-end cover, a piezoelectric ceramic, an electrode plate and a front-end cover in sequence; the front-end cover and the back-end cover are compressed and fixed by compression bolts; the upper end parts of the front-end coversof the two piezoelectric vibrators are integrated to form a driving foot by a flexible hinge with a suddenly-diminished sectional area; the stator is provided with the two asymmetrical working modes;when any asymmetrical working mode is excited, motion trails of material points on the surface of the driving foot of the stator are in a skew line; and the direction of dip of the skew line is changed with changes of the working modes so as to push the forward and reverse motions of the guide rail. The ultrasonic motor is large in thrust, wide in driving frequency band and reliable in work.

Description

Technical field: [0001] The invention relates to an asymmetric structure similar to a tower-shaped ultrasonic motor and an asymmetric mode and electric excitation mode, belonging to the field of ultrasonic motors. Background technique: [0002] Ultrasonic motor is a new type of power output device that utilizes the inverse piezoelectric effect of piezoelectric ceramics and ultrasonic vibration. Among them, the linear motion ultrasonic motor is a kind of ultrasonic motor. Compared with the traditional electromagnetic motor, the ultrasonic motor has the advantages of low speed and high torque, fast transient response, high positioning accuracy, good control characteristics, no magnetic field and no magnetic field influence, etc. It has great advantages in precision drive, medical equipment, aerospace and other fields. Wide application prospects. [0003] It is found through literature retrieval of existing approximate tower-shaped ultrasonic motors that Kurosawa et al. publi...

AI Technical Summary

Problems solved by technology

[0006] 2. Due to the error of theoretical calculation and actual processing, plus the contact between the stator and the rotor when the motor is working, changes in temperature and load, there is a certain degree of difference in the resonance frequency of the two orthogonal working modes;

[0007] 3. Under the excitation of a single frequency alternating signal, due to a certain degree of difference in the resonance frequency of the two orthogonal operating modes, the two orthogonal operating modes cannot be excited to the maximum at the same time, which affects the performance of the motor. The operating efficiency and performance also make the frequency domain that the motor can drive narrow

Its disadvantage is that the clamping position of the stator is not placed near the node, node line or node surface of the working mode, which will cause the clamping of the stator to affect the working mode and increase the energy loss; when the motor is working, only Half of the piezoelectric sheet is working, which is not conducive to improving the mechanical output performance of the motor; in order to take into account both forward and reverse motion, the position of the motor driving foot is not at the maximum amplitude, and the vibration energy utilization rate is not high

Images