Preface:
With the development of science and technology, more and more new technological applications are realized, and ultrasonic motor is one of them.This technology combines the disciplines of vibration, fluctuation, tribology, dynamic design, power electronics, automatic control, new materials and new processes to provide completely new applications for motor development.
What is an ultrasonic motor?
Ultrasonic motor, different from the traditional motor using electromagnetic cross force to obtain its motion and torque, it is the use of piezoelectric ceramic inverse piezoelectric effect and ultrasonic vibration to obtain its motion and torque, the material's microscopic deformation through the mechanical resonance amplification and friction coupling into the rotor's macro-motion. In this new type of motor, the piezoelectric ceramic material disc replaces many copper coils.
Ultrasonic motor is mainly composed of stator piezoelectric ceramics and rotor friction material, etc. The use of piezoelectric ceramics of the inverse piezoelectric effect, so that the stator surface plasma to produce ultrasonic frequency domain of the ellipsoidal vibration, through the contact friction between the rotor and the stator to drive the rotation of the rotor.
What are the application advantages of ultrasonic motors?
Compared with the traditional electromagnetic motor, ultrasonic motor has the advantages of compact structure, small volume and light weight; fast response speed, good control characteristics; low-speed large torque; stopping with a holding torque; no electromagnetic interference, suitable for harsh working environments and other application advantages.
1、Small size and light weight
Ultrasonic motor has no coil, no magnet, fine structure, compared with ordinary motors, in the case of the same output torque, it can be made smaller, lighter and thinner.
2、fast response speed, good control characteristics
Ultrasonic motor is driven by friction, the mass of the moving body is light, inertia is small, response speed is fast, the starting and stopping time is milliseconds in magnitude. Therefore it can achieve high precision speed control and position control.
3、Nanoscale control precision
The ability of ultrasonic motors to achieve nanoscale precision control is the result of the synergistic effect of multiple factors. Firstly, the extremely high vibration frequency of the ultrasonic motor makes the step angle extremely small, thus achieving fine control. Second, by precisely adjusting the voltage applied to the piezoelectric material, the amplitude and frequency of the vibration of the motor can be precisely controlled, which in turn controls the motion of the motor. Thirdly, the ultrasonic motor adopts frequency conversion control and phase difference control technology to optimise the speed and torque output of the motor and achieve precise position control. Fourth, the ultrasonic motor is equipped with a closed-loop control system with high-precision sensors, which can monitor and feedback the actual position and motion status of the motor in real time, and after comparing it with the desired value, it can achieve nanometer-level precision through automatic adjustment.
4、Self-locking when work stops, no heat generation
When the motor stops working, the vibration of the vibrating element also stops, the friction disappears, and the motor can naturally remain in its current position, achieving self-locking. On the other hand, the coreless design of the ultrasonic motor means that there is no continuous current flow through the motor when it stops working, so no additional heat is generated and there is no heat loss inside the motor due to hysteresis and eddy current effects.
5、no electromagnetic interference, suitable for strong magnetic field and other harsh working environment
Ultrasonic motor has no magnetic pole, so it is not affected by electromagnetic induction. At the same time, it does not produce electromagnetic interference to the outside world, especially suitable for the working environment under strong magnetic field. In the environment with strict requirements for EMI (electromagnetic interference), the use of ultrasonic motors is also very suitable.
What are the applications of ultrasonic motors?
An ultrasonic motor produces motion by taking steps, so it can be used in different ways depending on the requirements of a particular application.By way of analogy, an ultrasonic motor is like a human being in that it can walk in different ways. It can move fast or slow, take long, short or partial steps, or stop at any point. All this is done through different movement patterns and frequencies of the legs.
1、Ultrasonic motor drive high-speed auto focus axis
A high-speed autofocus axis is required to track the cell terrain. The motion determines the harsh step size for continuous movement at the tens of nanometre level to maintain focus.
2、Ultrasonic motor driven digital microscope
Digital microscopes utilise a high performance XY stage to perform dynamic scanning at a high constant speed or step and repeat for automated image acquisition. The precision stage is designed to hold multiple samples for transmission or reflection imaging.
3、Ultrasonic motor drive wafer inspection stage
Provides X-axis and Y-axis travel for the wafer inspection stage to support 450mm diameter wafers. The stage provides absolute positional stability at rest, no EMI, and built-in hold and brake functions for contact and non-contact measurement.
4、Ultrasonic motor drive carrier table
Sonic motors can drive all kinds of carrier tables, such as electron and ion beam carrier tables, spectroscopy carrier tables, electron and ion beam carrier tables, electron and ion beam carrier tables, multi-axis carrier tables, non-magnetic bi-axial rotating carrier tables, etc.
Summary:
As a precision drive technology, ultrasonic motors are widely used in various high-tech fields, including imaging equipment, industrial automation equipment, and surgical equipment. As an emerging technology, the application of ultrasonic motors in the field of precision drive is promising and is expected to play a more important role in the future industrial and scientific and technological fields.
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