CN106452170A - Surface acoustic wave rotary motor - Google Patents

Abstract

The invention relates to an ultrasonic rotary motor based on surface acoustic wave, mainly comprising a fixing shell, a surface acoustic wave device, push plates, an upper retaining plate and a rotor, wherein the surface acoustic wave device comprises two pairs of interdigital transducers and a piezoelectric substrate. The part of a rotor in contact with the piezoelectric substrate is positioned in an area between the two pairs of interdigital transducers, certain pressure is applied to the left and right push plates and the upper retaining plate, a high-frequency sinusoidal signal is applied to the specified interdigital transducer to excite the surface acoustic wave device to generate surface acoustic wave, and the rotor can be rotated clockwise and anticlockwise by the aid of frictional force between the rotor and the piezoelectric substrate. The ultrasonic rotary motor has the advantages of simple structure, small size, high drive precision, low control difficulty, low cost and the like.

Description

A Surface Acoustic Wave Rotary Motor

technical field

The invention belongs to the field of ultrasonic motors, in particular to a surface acoustic wave rotary motor.

Background technique

With the rapid development of modern science and technology, the role of micro-machines in social production is becoming more and more prominent. Therefore, as the core component of micro-mechanical systems, micro-motors have attracted extensive attention from domestic and foreign researchers. Although the traditional electromagnetic motor has the advantages of fast speed, high power, and high energy utilization rate, its internal structure is relatively complicated, and because its driving principle is to use the electromagnetic force between the rotor magnet and the stator coil to drive the rotor to rotate, it is easily affected by the outside world. Electromagnetic interference, in addition, the traditional electromagnetic motor has a large size and low driving precision.

Because traditional electromagnetic motors are difficult to apply to micro-mechanical systems, a piezoelectric ultrasonic motor driven by friction has entered people's field of vision. The piezoelectric ultrasonic motor has high positioning accuracy, low speed and high torque, no electromagnetic interference, small size, no Noise and other advantages.

In the mid-1990s, Japanese scholars Kurosawa and others proposed the surface acoustic wave motor, which is also a kind of piezoelectric ultrasonic motor, but compared with ordinary piezoelectric ultrasonic motors, the surface acoustic wave motor is easy to control and smaller in size , with nanometer-level positioning accuracy, and it adopts high-precision surface micromachining manufacturing technology, so it has higher reliability and work efficiency. However, most of the surface acoustic wave motors studied by scholars at home and abroad are of a single linear type, and there are very few studies on the rotary surface acoustic wave motor. In view of this, the present invention proposes a surface acoustic wave rotary motor, which uses surface acoustic waves to make solid surface particles generate elliptical motion trajectories, and relies on the friction between the rotor and the contact surface to drive the rotor to achieve rotational motion.

Contents of the invention

The purpose of the present invention is to provide a surface acoustic wave rotary motor to solve the problem that the current surface acoustic wave motor is difficult to realize the rotary motion.

In order to solve the problems of the technologies described above, the technical solution adopted in the present invention is:

The surface acoustic wave rotary motor is composed of a fixed housing (1), four surface acoustic wave devices (2), two push plates (5), an upper baffle (6) and a rotor (7). The device (201) is fixed on the lower surface of the inner wall of the fixed housing (1); the surface acoustic wave device (202) is fixedly bonded to the push plate (502), placed on the right surface of the inner wall of the fixed housing (1), and the push plate ( 502) and the hole of the fixed shell (1) are clearance fit; the surface acoustic wave device (204) is fixedly bonded to the push plate (501), placed on the left surface of the fixed shell (1) inner wall, and the push plate ( 501) and the hole of the fixed housing (1) are in clearance fit; the rotor (7) is placed in the fixed housing (1) and is in tangential contact with each surface acoustic wave device (2); the surface acoustic wave device (203) It is fixedly bonded to the upper baffle (6), placed above the rotor (7), and the surface acoustic wave device (2) is in tangential contact with the rotor (7).

The surface acoustic wave device (2) includes two pairs of interdigital transducers (3) and piezoelectric substrates (4), and the interdigital transducers (3) are sputtered on the piezoelectric substrates using MEMS micromachining technology. (4) SURFACE.

The contact area between the rotor (7) and the piezoelectric substrate (4) is between two pairs of interdigital transducers (3), and the piezoelectric substrate (4) forms a polygon to surround the rotor (7), and the rotor ( 7) It is tangent to each piezoelectric substrate (4), and the contact line between the rotor (7) and the piezoelectric substrate (4) is the symmetrical center line of the piezoelectric substrate (4). The electric substrate (4) is vertical and points to the tangential contact line, and the contact length between the rotor (7) and the surface acoustic wave device (2) is shorter than the length of the interdigital transducer (3).

The surface acoustic wave rotary motor is driven by the friction between the rotor (7) and the piezoelectric substrate (4), and a certain pressure is applied to the left and right push plates (5) and the upper baffle plate (6). The high-frequency sinusoidal signal applied by the finger transducer (3) can realize clockwise rotation and counterclockwise rotation of the rotor (7).

Working principle of the present invention:

Connect the interdigital transducer with the high-frequency signal generator and the two poles of the power amplifier, and apply a high-frequency sinusoidal signal to the interdigital transducer. Due to the inverse piezoelectric effect of the piezoelectric substrate, a The surface acoustic wave propagating to the surrounding, because the surface acoustic wave has the characteristic of making the solid surface particle generate an elliptical motion track, the rotor is placed on the surface of the piezoelectric substrate, and a certain pre-pressure is applied to the rotor, and the friction between the rotor and the piezoelectric substrate is used The force can realize the movement of the rotor, and because there is friction force for driving around the rotor, the rotation of the rotor can be realized finally.

The invention has the advantages that: the amplitude of the surface acoustic wave is at the nanometer level, and the driving precision of the rotor can also reach the nanometer level. Compared with the ordinary piezoelectric ultrasonic motor, the surface acoustic wave rotary motor has higher driving precision, and the surface acoustic wave The structure of the wave motor is simpler and the size is smaller, which can solve the technical problem that the current micro-motor is difficult to achieve nanometer-level driving precision.

Description of drawings

Figure 1 is an isometric view of the front of the invention.

Figure 2 is an exploded view of the structure of the present invention.

Figure 3 is an isometric view of a surface acoustic wave device.

Fig. 4 is a schematic diagram of the second embodiment.

Fig. 5 is a driving schematic diagram of a surface acoustic wave motor.

Including: fixed shell 1 surface acoustic wave device 2 (201,202,203,204)

Interdigital transducer 3 (301, 302, 303, 304, 305, 306, 307, 308)

Piezoelectric substrate 4 (401,402,403,404) push plate 5 (501,502) upper baffle plate 6

Rotor 7

detailed description

Referring to Figure 1, Figure 2, Figure 3, Figure 4, and Figure 5:

The invention proposes a surface acoustic wave rotary motor, which includes a fixed shell (1), four surface acoustic wave devices (2), two push plates (5), an upper baffle (6) and a rotor (7). The surface wave device (201) is fixed on the lower surface of the inner wall of the fixed housing (1) by bonding; the surface acoustic wave device (202) is fixedly bonded to the push plate (502), and placed on the inner wall of the fixed housing (1). On the right surface, the round platform of the push plate (502) is in clearance fit with the hole of the fixed shell (1); the surface acoustic wave device (204) is fixedly bonded to the push plate (501), and placed on the inner wall of the fixed shell (1). On the left surface, the round platform of the push plate (501) is in clearance fit with the hole of the fixed housing (1); the rotor (7) is placed in the fixed housing (1) and is in tangential contact with each surface acoustic wave device (2); The surface wave device (203) is fixedly bonded to the upper baffle (6), placed above the rotor (7), and the surface acoustic wave device (2) is in tangential contact with the rotor (7). The surface acoustic wave device (2) includes two pairs of interdigital transducers (3) and a piezoelectric substrate (4), and the interdigital transducers (3) are sputtered on the piezoelectric substrate (4) by MEMS micromachining technology. On the surface, the material of the interdigital transducer (3) can be selected from aluminum, the material of the piezoelectric substrate (4) is usually selected from lithium niobate, and the material of the rotor (7) can be selected from aluminum.

The peak-to-peak voltage of the input signal of the interdigital transducer (3) is 20V-50V, and the pre-pressure applied to the left and right push plates (5) and the upper baffle plate (6) is 10N-100N.

Embodiment one: as shown in Figure 1, the plane formed by the contact line between the rotor (7) of the surface acoustic wave rotary motor and a certain piezoelectric substrate (4) and the axis of the rotor (7) is the rotor (7) and the acoustic plane. On the symmetrical plane of the surface wave device (2), a certain preload is applied to the left and right push plates (5) and the upper baffle (6), and then the same sinusoidal signal is applied to the interdigital transducers (301, 303, 305, 307), and the same sinusoidal signal is applied to the interdigital transducers (302,304,306,308) do not apply signals, and the counterclockwise rotation of the rotor (7) can be realized; apply the same sinusoidal signal to the interdigital transducers (302,304,306,308), and do not apply signals to the interdigital transducers (301,303,305,307), and the rotor (7) can be realized ), the clockwise rotation speed of the rotor is equal to the counterclockwise rotation speed of the rotor without changing other parameters.

Embodiment 2: As shown in Figure 4, the plane formed by the contact line between the rotor (7) of the surface acoustic wave rotary motor and any piezoelectric substrate (4) and the axis of the rotor (7) is not the rotor (7) With the plane of symmetry of the surface acoustic wave device (2), a certain preload is applied to the surface acoustic wave device (202, 203, 204), and then the same sinusoidal signal is applied to the interdigital transducer (301, 303, 305, 307), and the interdigital transducer (302, 304, 306, 308) does not Applying a signal can realize counterclockwise rotation of the rotor (7); applying the same sinusoidal signal to the interdigital transducers (302, 304, 306, 308) and not applying a signal to the interdigital transducers (301, 303, 305, 307) can realize clockwise rotation of the rotor (7). Rotation, the clockwise rotation speed of the rotor is not equal to the counterclockwise rotation speed of the rotor under the condition of not changing other parameters.

Claims (5)

1. A surface acoustic wave rotary motor, said surface acoustic wave rotary motor consists of a fixed housing (1), four surface acoustic wave devices (2), two push plates (5), an upper baffle plate (6) and a rotor (7), wherein the surface acoustic wave device (2) includes two pairs of interdigital transducers (3) and a piezoelectric substrate (4); the surface acoustic wave device (201) is fixed on a fixed housing (1) The lower surface of the inner wall; the surface acoustic wave device (202) is fixedly bonded to the push plate (502), placed on the right surface of the inner wall of the fixed housing (1), and the round platform of the push plate (502) is connected to the fixed housing (1) The hole is a clearance fit; the surface acoustic wave device (204) is fixedly bonded to the push plate (501), placed on the left surface of the inner wall of the fixed housing (1), and the round platform of the push plate (501) and the fixed housing (1) The holes are clearance fit; the rotor (7) is placed in the fixed casing (1) and is in tangential contact with each surface acoustic wave device (2); the surface acoustic wave device (203) is fixedly bonded to the upper baffle (6), and placed above the rotor (7), and the surface acoustic wave device (2) is in tangential contact with the rotor (7), characterized in that: the contact area between the rotor and the piezoelectric substrate is between two pairs of interdigital transducers, and The piezoelectric substrate constitutes a polygon surrounding the rotor. 2 . A surface acoustic wave rotary motor according to claim 1 , wherein the rotor is tangent to each piezoelectric substrate, and the acting direction of the pre-pressure is perpendicular to the piezoelectric substrate and points to the tangential contact line. 3. A surface acoustic wave rotary motor according to claim 1, characterized in that clockwise or counterclockwise rotation of the rotor can be achieved by applying a high-frequency sinusoidal signal to a specific interdigital transducer. 4. A surface acoustic wave rotary motor according to claim 1, characterized in that: when the plane formed by the contact line between the rotor and a certain piezoelectric substrate and the axis of the rotor is the plane of symmetry between the rotor and the surface acoustic wave device , the speed of clockwise rotation of the rotor is equal to the speed of counterclockwise rotation; when the plane formed by the contact line between the rotor and any piezoelectric substrate and the axis of the rotor is not the symmetry plane of the rotor and the surface acoustic wave device, the clockwise rotation of the rotor The speed of clockwise rotation is not equal to the speed of counterclockwise rotation. 5. A surface acoustic wave rotating motor according to claim 1, characterized in that: the contact length between the rotor and the surface acoustic wave device is smaller than the length of the fingers of the interdigital transducer.