CN2535972Y - Surface elastic wave motor - Google Patents

Abstract

The surface elastic wave motor of the present utility model has a stator and a mover, and the stator includes a piezoelectric material substrate and transducers arranged at the left and right ends of the substrate to convert the high-frequency excitation voltage into a surface elastic wave. Linear guide rails are fixed on both sides of the piece respectively, and the mover is a multi-contact mover, which includes a slider and a mover substrate that slide along the linear guide rail, and a pressure spring is set between the mover substrate and the slider. The bottom of the sub-base has contact groups that are in contact with the surface of the stator substrate. When working, when the ultra-high-frequency excitation voltage is applied to the transducer, the contact group and the surface particles of the piezoelectric substrate will have a mutual motion tendency, and the surface elastic wave will push the multi-contact mover to move in a straight line through friction. The surface elastic wave motor of the utility model has the advantages of simple structure, small heating loss, high efficiency, low noise, fast response, easy realization of miniaturization and meeting the requirements of small step length, high speed and large thrust.

Description

surface elastic wave motor

technical field

The utility model relates to a motor which utilizes piezoelectric effect for linear motion.

Background technique

With the development of science and technology and modern industry, in many special fields, it is necessary to use electric motors (or motors) with special performance as the motion source of the motion system, or as the power source of the operating system. Existing motors mainly include electromagnetic induction motors, electrostatic motors and ultrasonic motors. Electromagnetic induction motors have fast speed, large torque and high power; however, due to the use of electromagnetic coils and gear shaft transmission mechanisms, the heat loss is large and it is not easy to miniaturize. Electrostatic motors directly use electrostatic force to drive the rotor, without the need for electric solenoid coils, and can be miniaturized, but the torque is small, and the friction and noise between the stator and rotor are relatively large, so the motor often needs to be soaked in oil to run. Ultrasonic motor is a new type of special motor developed in recent years. The stator of this type of motor is made of piezoelectric material and elastic body with many slots processed. Based on this, the ultrasonic vibration of piezoelectric material is amplified, and then the rotor is driven by friction material. Generate motion, the working frequency is about 50KHz. The biggest feature of the existing ultrasonic motor is low speed, high torque and high efficiency, and it has been applied in the optical focusing mechanism of cameras and video cameras. However, it is difficult to achieve high speed, and the service life is generally not long. The reason is that the piezoelectric material is easily damaged by fatigue, and the friction and heat will quickly deteriorate the adhesive. In addition, the motor structure is not easy to further miniaturize.

Contents of the invention

The purpose of the utility model is to provide a surface elastic wave motor with large torque, high speed, fast response and easy miniaturization.

The surface elastic wave motor of the present utility model has a stator and a mover, and the stator includes a piezoelectric material substrate and transducers arranged at the left and right ends of the substrate to convert the high-frequency excitation voltage into a surface elastic wave. Linear guide rails are fixed on both sides of the piece respectively, and the mover is a multi-contact mover, which includes a slider and a mover substrate that slide along the linear guide rail, and a pressure spring is set between the mover substrate and the slider. The bottom of the sub-base has contact groups that are in contact with the surface of the stator substrate.

The above-mentioned piezoelectric material substrate can be Zno or quartz or LiTaO ₃ or Bi ₁₂ GeO ₂₀ substrate.

The transducer can be an interdigital transducer or a wedge transducer. The contact group at the bottom of the mover substrate and the surface of the stator substrate can use steel balls or have protrusions on the mover substrate.

When working, when a 1-30MHz ultra-high frequency excitation voltage is applied to the left end transducer, the surface of the piezoelectric substrate of the stator and the particles on the shallow layer will reciprocate counterclockwise with an elliptical trajectory, thus generating a vibration along the stator. A surface elastic wave propagating to the right of the surface. There will be a mutual motion tendency between the contact group and the surface particles of the piezoelectric substrate, and the surface elastic wave pushes the multi-contact mover to move to the left through friction. So the whole mover moves to the left along the linear guide rail. Similarly, if an excitation voltage is applied to the transducer at the right end, the rightward drive of the SAW motor can be conveniently realized. Changing the frequency and amplitude of the excitation voltage of the transducer, and the pressure of the reed can conveniently control the moving speed, step distance and driving force of the mover.

The surface elastic wave motor of the utility model has the advantages of simple structure, small heating loss, high efficiency, low noise, fast response, easy realization of miniaturization and meeting the requirements of small step length, high speed and large thrust.

Description of drawings

Figure 1 is a schematic diagram of the specific structure of a surface elastic wave motor;

Fig. 2 is the top view of Fig. 1;

Fig. 3 is the left view of Fig. 1;

Fig. 4 is a schematic diagram of a specific structure of the transducer installed on the stator.

Detailed ways

Referring to Fig. 1, Fig. 2, and Fig. 3, the surface acoustic wave motor has a stator and a mover, and the stator includes a piezoelectric material substrate 1 and transducers 2 arranged at the left and right ends of the substrate 1. In this example, piezoelectric The material is LiTaO ₃ crystal substrate. In order to obtain high surface acoustic wave conversion efficiency, generally, the transducer is shown in Figure 4, using an interdigital transducer, which is composed of two finger-like electrodes 9 and 10 with alternating polarities interposed opposite each other. Gaps 11 are left, and the positive and negative polarities are arranged alternately. In this way, when an alternating voltage is applied to the two finger electrodes, an alternating electric field will be established in the LiNbO ₃ piezoelectric crystal substrate, and due to the piezoelectric effect, the alternating electric field will be excited in the piezoelectric crystal substrate. The corresponding elastic vibrations propagate on the surface to form surface elastic waves. As shown in the figure, two linear guide rails 3 are respectively fixed on the supports 4 on both sides of the substrate 1 . The mover includes a slider 5 slidingly matched with the linear guide rail, a mover substrate 6, and a compression spring 7 is provided between the mover substrate 6 and the slider 5, as shown in the example, the bottom of the mover substrate and the surface of the stator substrate The contact point group adopts densely packed and bonded steel ball group 8 , and the steel ball group 8 forms multi-point contact with the surface of the stator substrate 1 by utilizing the elastic force exerted by the compression spring 7 . Because the contact area between the ball and the plane is small, under the same pressure, the contact pressure between the steel ball and the surface elastic wave is large, and the friction force between them is also large, and a large driving force generated by the friction force can be obtained. Reducing the width of the electrode line and reducing the diameter of the steel ball, such as using a steel ball with a diameter of 0.5mm or less, can miniaturize the motor.

Usually, the upper and lower heights of the support 4 are adjustable, so that the elastic force applied by the pressure spring to the contact group can be changed, so that the positive pressure between the contact group at the bottom of the mover substrate and the surface elastic wave can be adjusted arbitrarily.

Claims (3)

1. The surface elastic wave motor is characterized in that it has a stator and a mover. The stator includes a piezoelectric material substrate [1] and a high-frequency excitation voltage conversion device arranged at the left and right ends of the substrate [1]. The surface elastic wave transducer [2] is fixed with a linear guide rail [3] on both sides of the substrate [1], and the mover is a multi-contact mover, which includes a slider sliding along the linear guide rail [3]. block [5] and mover base plate [6], a compression reed [7] is set between the mover base plate [6] and the slider [5], and the stator base is fixed on the bottom of the mover base plate [6]. The surface of the sheet [1] is in contact with the contact group [8]. 2. The surface elastic wave motor according to claim 1, characterized in that said transducer [2] is formed by interposing two finger electrodes [9], [10] with alternating polarities, There is a gap between the electrodes [11], and the positive and negative polarities are staggered. 3. The surface elastic wave motor according to claim 1, characterized in that said piezoelectric material substrate [1] is a Zno or quartz or LiTaO ₃ or Bi ₁₂ GeO ₂₀ substrate.

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