CN100367650C - Micro supersonic motor device using magnetic pressure - Google Patents

Abstract

The invention relates to a micro-ultrasonic motor device using magnetic pressure, which belongs to the field of ultrasonic applications. The device includes a stator for exciting ultrasonic vibration, a rotor and a device for providing pre-pressure between the rotor and the stator. The ceramic element and the matching block connected to it are made of materials that can generate magnetic attraction between the magnet; the rotor is composed of a non-magnetizable base and a magnet connected to it, and the magnetic force provided by the magnet is sufficient to bear the rotor itself. Gravity, and provide pre-pressure between the stator and the rotor so that the rotor can rotate. The ultrasonic motor is simple in structure, easy to manufacture and easy to miniaturize. In addition, the structure of the rotor also makes it easy to use. The invention will have broad application prospects in the fields of biology, medical treatment, micro-mechanics and the like.

Description

A Micro Ultrasonic Motor Device Using Magnetic Pressure

technical field

The invention belongs to the field of ultrasonic applications, in particular to a miniaturized ultrasonic motor structure design.

Background technique

The piezoelectric ultrasonic motor is a driving mechanism made of a specific structure using the inverse piezoelectric effect of piezoelectric materials. It is generally composed of functional components such as a stator, a rotor, and a pre-pressure mechanism. It uses the inverse piezoelectric effect of piezoelectric ceramics to generate ultrasonic vibrations on the surface of the stator, and the friction between the stator and the rotor drives the rotor to move. Ultrasonic motors have the following advantages over ordinary electromagnetic motors:

1. With low speed and high torque, it can directly drive the load without deceleration mechanism.

2. Small size, flexible structure, power volume ratio is 3-10 times that of electromagnetic motor.

3. Quick start and stop response, the response time is less than 1 millisecond.

4. It does not generate electromagnetic interference, nor is it subject to electromagnetic interference.

5. With self-holding torque, no gear backlash, and precise positioning.

6. Quiet and noiseless operation.

Bending vibration mode ultrasonic motor is a kind of ultrasonic motor. Its structure is relatively simple compared with other ultrasonic motors. It is also mainly composed of a stator that excites ultrasonic vibration, a rotor/shaft that outputs torque, and a pre-pressure mechanism that pressurizes the rotor. , the said stator is mainly composed of a piezoelectric ceramic element that excites vibration and a matching block. At the same time, bending vibration mode ultrasonic motors are divided into piezoelectric sheet drive motors and piezoelectric tube drive motors according to the way of exciting bending vibration and the shape of piezoelectric ceramic elements. Their transmission principles and drive mechanisms are the same, as shown in Figure 1. The stator is in the vibration mode of circular shaking, and there is a small gap between the stator 11 and the ring-shaped rotor 12. During the transmission, the stator moves while bending, so there is a tangential contact between the stator and the rotor, and the contact point is outside the stator. Moving on the periphery of the circle, in turn, the friction between the stator and the rotor causes the rotor to rotate in the opposite direction to the direction of movement of the contact point.

The key to the rotor movement of the ultrasonic motor is to make the rotor contact with the stator and provide a certain pressure, so that the ultrasonic vibration on the surface of the stator drives the rotor to move through the friction between the rotor and the stator. Therefore, in order to make the rotor rotate, there needs to be a device to provide pre-pressure between the rotor and the stator. Two existing structures for providing preload are shown in Fig. 2 and Fig. 3 . 2 is a motor with a shell locking structure. The entire driving mechanism is covered in a metal shell 20. The shell provides a pre-pressure between the rotor 24 and the stator 25 by pressing the spring 23 through the rubber pad 21 and the polytetrafluoroethylene ring 22. Fig. 3 is a piezoelectric cylindrical ultrasonic motor with a fixed shaft structure, in which a spring 33 provides pressure between the rotor and the stator.

The structural feature of the existing ultrasonic motor is that it is relatively complicated to provide a pre-pressure device, and it is relatively troublesome to realize. In addition, the rotating device provided to the outside world is a thin shaft (as shown in Figure 2), or a spring-loaded annular rotor (as shown in Figure 3), which is not conducive to use in some cases.

Contents of the invention

The purpose of the present invention is to overcome the deficiencies of the prior art, and propose a micro-ultrasonic motor device using magnetic pressure, the pre-pressure required for rotation is provided by the magnetic force between the magnet and the stator. The ultrasonic motor has a simple structure, is easy to be miniaturized, and has wide application prospects in the fields of biology, medical treatment, micro-mechanics and the like.

The present invention proposes a micro-ultrasonic motor device utilizing magnetic pressure, comprising a stator that excites ultrasonic vibrations, a rotor, and a device that provides pre-pressure between the rotor and the stator, and is characterized in that the stator is composed of piezoelectric ceramic elements that excite vibrations and a matching block made of a material that can generate an attractive force between the magnet; the rotor is composed of a non-magnetizable base and a magnet connected to it, and the magnetic force provided by the magnet is sufficient to bear the gravity of the rotor itself. And provide the pre-pressure between the stator and the rotor so that the rotor can rotate.

When the ultrasonic motor using magnetic pressure of the present invention is in use, it only needs to fix the rotor and the rotating device together by mechanical fixing or bonding, and the rotation of the rotor will provide power for the entire rotating device.

In the present invention, the pre-pressure required for rotation is provided by the magnetic force between the magnet of the rotor and the stator. It has the advantages of simple structure, easy manufacture, easy miniaturization and easy use.

The invention will have wide application prospects in the fields of biology, medical treatment, micro-mechanics and the like.

Description of drawings

Figure 1 is a schematic diagram of the shaking head movement of the ultrasonic motor.

Fig. 2 is a schematic structural diagram of an existing external locking ultrasonic motor.

Fig. 3 is a schematic structural diagram of an existing ultrasonic motor with a fixed shaft.

Fig. 4 is a schematic diagram of an embodiment of the stator structure of the ultrasonic motor according to the present invention.

Fig. 5 is a schematic diagram of an embodiment of the rotor structure of the ultrasonic motor of the present invention.

Detailed ways

The ultrasonic motor device of the present invention includes two main parts, a stator and a rotor. The stator structure embodiment is shown in Fig. 4, and it is made of the cylindrical piezoelectric ceramic element 42 that excites vibration and the cylindrical matching block 41 that is connected with it (piezoelectric ceramic element and matching block also can adopt other shapes), and this matching block 41 A protruding shaft is connected on the surface, and the matching block and the protruding shaft can be integrally processed by ordinary steel (other materials that generate magnetic attraction force with the magnet can also be used), and the protruding shaft of the matching block plays a positioning role. The ultrasonic motor rotor structure embodiment is shown in Figure 5. This rotor is made of an aluminum cylinder or stainless steel cylinder 52 with a hole in the center and a disc-shaped magnet 51 on it. The disc-shaped magnet is made of a permanent magnet material, such as NdFeB. , ferrite, etc. The two are fixed together by superglue or mechanical means. It can be used only by fitting the rotor and the stator through the shaft hole. A hole in the center of the rotor forms a mating relationship with the protruding shaft of the stator. In order to make the bonding easier, the hole of the aluminum column in this embodiment is processed as a blind hole, that is, one end of it is not opened, of course it can also be used. Since the material of the protruding shaft of the stator matching block is a material that can generate magnetic attraction force with the magnet, an attraction force is generated between the protruding shaft and the magnet of the rotor, so that the rotor can be adsorbed on the stator and provide a pre-pressure between the rotor and the stator. to drive the rotor to rotate. Wherein the aluminum column can also be made of other non-magnetizable materials, but cannot be made of magnetizable materials, otherwise its magnetization will make the pressure between the rotor and the stator very small, which is not enough to provide the power for the rotor to rotate.

The overall size of this embodiment is: the diameter of the stator and the rotor is 2 mm, the length of the magnet is 2 mm, and the length of the rotor and the stator is not more than 8 mm when they are assembled together.

Claims (2)

1. A micro-ultrasonic motor device utilizing magnetic pressure, comprising a stator that excites ultrasonic vibrations, a rotor and a device that provides a preload between the rotor and the stator, it is characterized in that said stator consists of piezoelectric ceramic elements that excite vibrations and its The connecting block is composed of a matching block made of a material that can generate magnetic attraction between the magnet; the rotor is composed of a non-magnetizable base and a magnet connected to it, and the magnetic force provided by the magnet is sufficient to bear the gravity of the rotor itself, and The pre-pressure between the stator and the rotor is provided so that the rotor can rotate; the rotor base is a non-magnetic cylinder with a blind hole or a through hole in the center, and the magnet is a disc-shaped magnet corresponding to the cross-sectional shape of the cylinder. Said matching block of the stator has a protruding shaft matched with the hole of the rotor, and the stator and the rotor are assembled into one body through the cooperation of the shaft and the hole. 2. The micro-ultrasonic motor device utilizing magnetic pressure as claimed in claim 1, wherein said matching block is integrally processed by ordinary steel, said rotor base body is made of aluminum or stainless steel, said The magnet is made of permanent magnet material, and the magnet and the rotor base are fixed together by superglue or mechanically.

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