Two-way single-mode ramp type tower-shaped linear ultrasonic motor and electric excitation method

Abstract

The invention relates to a two-way single-mode ramp type tower-shaped linear ultrasonic motor and an electric excitation method thereof, and the two-way single-mode ramp type tower-shaped linear ultrasonic motor belongs to the ultrasonic motors and comprises a stator, piezoelectric ceramics and a guide rail. The guide rail is pressed on a stator drive foot by pre-pressure and inclines with a Theta angle. The stator comprises the drive foot, a flexible amplifying round hole and a tower-shaped metal body of two rectangular columns, and six piezoelectric ceramics are symmetrically adhered on the outer surface of the tower-shaped metal body and used for exciting two orthogonal working modes (x-z section bending vibration mode and y-z section symmetrical vibration mode including local bending vibration) of the stator. When a single-phase voltage signal is used for exciting any one working mode of the stator, a motion curve of mass points on the surface of the stator drive foot is a skew line oppositely to the guide rail, and the skew direction of the skew line is changed with the change of the working modes, thereby pushing the guide rail to move in a forward and reverse way. The ultrasonic motor has compact structure, high drive efficiency, large thrust-weight ratio and reliable working.

Description

Technical field: [0001] The bidirectional single-mode inclined rail tower-shaped linear ultrasonic motor and the electric excitation method of the present invention belong 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] According to the literature search of existing tower-shaped ultrasonic motors, Zhao Chunsheng et al. published the Chinese Invent...

AI Technical Summary

Problems solved by technology

[0004] The disadvantage of the above-mentioned motor is that when the motor is used to drive the mover to make a single-degree-of-freedom linear motion, only the symmetric-antisymmetric mode in the yoz plane or the symmetric-antisymmetric mode in the yoz plane is excited. can achieve the goal

The disadvantage is that the motor can only move in one direction and cannot reverse

The disadvantage is that the motor uses laminated piezoelectric ceramics as the drive element, which is more expensive; the motor can only provide a maximum driving force of 0.5N, which limits its application range

[0008] 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;

[0009] 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 impact of the clamping of the stator on the working mode and increase the energy loss; at the same time, in order to take into account the positive and negative direction movement, the position of the driving foot is not at the maximum amplitude, and the utilization rate of vibration energy is not high

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