CN210297571U

CN210297571U - Linear motor driven by laminated eight-rod piezoelectric stator

Info

Publication number: CN210297571U
Application number: CN201921757251.9U
Authority: CN
Inventors: 贺红林; 方志敏; 龙玉繁; 邓传涛; 乐敏杰
Original assignee: Nanchang Hangkong University
Current assignee: Nanchang Hangkong University
Priority date: 2019-10-19
Filing date: 2019-10-19
Publication date: 2020-04-10
Anticipated expiration: 2029-10-19

Abstract

The utility model discloses a linear electric motor that eight pole type piezoelectric stator of stromatolite promoted, including stator module, positioning platform and support subassembly, stator module and support subassembly fixed connection just contact through drive foot and positioning platform within positioning platform, form the sliding pair between positioning platform and the support subassembly, utilize eight pole type piezoelectric stator specific dual integral sign shape modals of stromatolite and two pincerlike mode drive positioning platform. The utility model has simple positioning mode, selects the center position of the rectangular block without vibration displacement as the stator clamping point and suspends and fixes the stator, thereby not only ensuring the positioning reliability, but also avoiding the problems of abnormal working mode and large amplitude drift of the mode frequency, which are possibly brought by clamping and fixing; the pre-pressure between the stator assembly and the positioning platform is adjusted through the adjusting screw and the elastic gasket, so that the motor is convenient to operate by a user, the structure of the motor is more compact and stable, and higher response speed, higher operation precision and higher output thrust can be generated.

Description

Linear motor driven by laminated eight-rod piezoelectric stator

Technical Field

The utility model relates to a precision drive piezoelectricity linear electric motor structure belongs to the piezoelectric motor field.

Background

The piezoelectric motor is used as a novel power mechanical part, electric energy is converted into vibration state mechanical energy based on the inverse piezoelectric effect of piezoelectric ceramics, and the vibration energy is converted into specific movement or rotation of the rotor through a friction process. Compared with the traditional electromagnetic motor, the piezoelectric motor has the advantages of simple structure, small size, light weight, quick response, low noise, power failure self-locking, no magnetic field interference, accurate movement and the like. The first patent related to piezoelectric motors was started by american scholars Williams a and Brown W in the last 40 th century, and the technology of piezoelectric motors and their products have been industrialized so far in technologically developed countries such as the united states, japan, germany, and the like. The piezoelectric motors are mainly classified into a rotary type piezoelectric motor and a linear type piezoelectric motor, the technology of the rotary type piezoelectric motor is mature day by day, and the development of the linear motor technology is relatively lagged. However, the linear motor has high positioning precision and precise movement because the stator directly drives the rotor and the transmission conversion mechanism is thrown, so that the linear motor has wide application prospect in the fields of precise driving of a movement workbench, driving of microscopic equipment, biomedical operation, IC etching, optical fiber butt joint, assembly and the like. Piezoelectric linear motors have become a hotspot in the study of piezoelectric motors. In 2008, a single rectangular plate composite mode linear ultrasonic motor is designed in time of use; in 2013, a fan-shaped stator ultrasonic motor is designed by utilizing a Langewen structure when Yaoqiang is far; in 2015, a triquetrum linear motor was proposed. In addition, other piezoelectric linear motors with new configurations meeting specific use requirements are proposed and developed in recent years, for example, a physical grating three-dimensional scanner needs to adjust the grating position in a narrow space of 29mm × 23mm × 3mm, an actuator with small volume, large execution force and quick response is needed for a buffer air bag to control the size of an air bag exhaust port in real time in a landing and buffering process, and an actuator with a flat structure is needed for driving a fuse explosion-proof mechanism to move in a fuse safety system, and the actuator is required to have no electromagnetic interference. Generally, many people have done much work and achieved a great deal of results in order to advance the development of linear motors. However, the current piezoelectric linear motor is far from mature, and the performance of the piezoelectric linear motor is far from the requirement of wide engineering application. On the one hand, it still generally has the power little, the inefficiency, the job is not steady scheduling problem, and on the other hand, the more limited linear electric motor structural style makes it still can't satisfy the various demands that the application field provided to it at present, so more the utility model linear electric motor new principle and dynamics structure still remain the important aspect of piezoelectric motor research.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to provide a linear electric motor that eight pole type piezoelectricity stators of stromatolite promote overcomes former linear electric motor stator location complicacy, the low, the slow and little shortcoming of output thrust of motion position resolution ratio.

The utility model provides a linear electric motor that eight pole type piezoelectricity stators of stromatolite promoted, includes stator module, location platform and support subassembly, its characterized in that: the stator assembly is connected with the support assembly and is arranged in the positioning platform, the positioning platform is connected with the stator assembly and the support assembly, and a moving pair is formed between the stator assembly and the support assembly, the stator assembly comprises a stator base body, a piezoelectric ceramic piece and a driving foot, the stator base body comprises a rectangular block and eight square rod bodies positioned at four corners of the front surface and the rear surface of the rectangular block, the rectangular block and the square rod bodies are of an integrated structure, the four square rod bodies positioned at the upper part of the rectangular block form an upper layer body, the four square rod bodies positioned at the lower part of the rectangular block form a lower layer body, a through hole is drilled at the center of the upper surface of the rectangular block, grooves are formed at the connecting ends of the square rod bodies and the rectangular block, blind holes are drilled at the centers of the square rod bodies, and the aim to reduce the; the piezoelectric ceramic plates are rectangular thin plates, are adhered to the periphery of the same position of the square rod body along the length direction and are divided into two groups, the piezoelectric ceramic plates adhered to the upper surface and the lower surface of each square rod body are double-clamp bending vibration excitation ceramic, the piezoelectric ceramic plates adhered to the two side surfaces of each square rod body are double integrator bending vibration excitation ceramic, and the driving feet are cuboid and arranged at the rod end positions of the upper surface and the lower surface of the stator base body.

A linear motor that eight pole type piezoelectricity stators of stromatolite promote, its characterized in that: the positioning platform comprises a lower layer plate, an upper layer plate and four stand columns, wherein the lower layer plate and the upper layer plate are rectangular plates and have the same peripheral size, a square groove is formed in the middle of the lower layer plate, the stand columns are square strips, one ends of the stand columns are fastened with the lower layer plate through platform screws, the other ends of the stand columns are fixed on the upper layer plate through platform screws, and elastic gaskets are pressed between the stand columns and the upper layer plate; the support assembly comprises a bottom plate and guide rail strips, wherein a boss is arranged at the center of the bottom plate, a threaded hole is formed in the boss, the section of each guide rail strip is concave, the two guide rail strips are fastened on the bottom plate through screws, a guide rail elastic gasket is arranged at the joint of each guide rail strip and the bottom plate, the two guide rail strips are parallel to each other, the grooves of the two guide rail strips are opposite, and mounting screws are arranged at four corners of the bottom plate; the lower layer plate of the positioning platform is connected with the guide rail bar of the support assembly and forms a moving pair; the stator assembly is arranged between the lower layer plate and the upper layer plate and is connected to the boss on the support assembly through a screw; the four driving feet on the upper layer body of the stator assembly are connected with the lower surface of the upper layer plate, and the four driving feet on the lower layer body are connected with the upper surface of the lower layer plate; the pre-pressure between the positioning platform and the stator assembly can be adjusted by adjusting the compression degree of the elastic gasket.

A linear motor that eight pole type piezoelectricity stators of stromatolite promote, its characterized in that: the working modes of the motor comprise a double integral symbol mode and a double clamp mode of the stator assembly, the double integral symbol mode specifies that the vibration of the stator only occurs in the plane where the upper layer body and the lower layer body are located, and the bending forms of two vertical rods of each layer body are completely consistent; the double-clamp mode refers to the fact that vibration of the stator occurs outside a plane where the two layers of bodies are located, bending forms of the upper portion and the lower portion of each vertical rod of the two-layer body structure are opposite, the double-clamp mode is used for achieving the purpose that the driving feet are alternately kept in contact with or separated from the positioning platform, and the double-integral-symbol mode is used for achieving the purpose that the driving feet are alternately pushed to move the positioning platform.

The utility model has the advantages that: the linear motor of the utility model has simple positioning mode, selects the center position of the rectangular block without vibration displacement as the stator clamping point and suspends and fixes the stator, thereby not only ensuring the positioning reliability, but also avoiding the problems of abnormal working mode and large amplitude drift of the modal frequency caused by clamping and fixing; the linear motor of the utility model adjusts the pre-pressure between the stator assembly and the positioning platform through the adjusting screw and the elastic gasket, thereby facilitating the operation of users and leading the structure of the motor to be more compact and stable; the utility model discloses a linear electric motor adopts the sufficient motion that directly promotes positioning platform of a plurality of drives of eight pole type piezoelectricity stators of stromatolite, and the sufficient driven mode of combining force of this kind of numerous drives can increase positioning platform's output thrust and speed at double and make its platform's operation more stable, guarantees that motor response speed is fast, can export great thrust and speed again when positioning accuracy is high.

Drawings

Fig. 1 is a schematic structural view of the present invention;

FIG. 2 is a side view of the structure of FIG. 1;

fig. 3 is a schematic structural view of a stator assembly in the present invention;

fig. 4 is a schematic structural view of the positioning platform of the present invention;

FIG. 5 is a schematic structural view of the middle support assembly of the present invention;

fig. 6 is a schematic diagram of a dual integral mode of the stator assembly of the present invention;

fig. 7 is a schematic view of a double-clamp mode of the stator assembly of the present invention;

fig. 8 is a schematic plan view of the arrangement of the piezoelectric ceramic positions of the upper body and the piezoelectric polarization and power supply configuration thereof according to the present invention;

fig. 9 is a schematic plan view of the piezoelectric ceramic position arrangement and its piezoelectric polarization and power supply configuration of the lower layer body according to the present invention;

fig. 10 is a schematic plan view illustrating the positioning platform pushed by the stator assembly of the present invention to move linearly;

in the figure: 1-stator component, 11-stator base body, 111-rectangular block, 112-square rod body, 12-piezoelectric ceramic plate, 13-driving foot, 2-positioning platform, 21-lower plate, 22-upper plate, 23-upright post, 24-platform screw, 25-elastic gasket, 3-support component, 31-bottom plate, 311-boss, 32-guide rail bar, 33-mounting screw, 34-screw and 35-guide rail elastic gasket.

Detailed Description

The structure of the present invention will be described in detail with reference to the accompanying drawings:

a linear motor pushed by a laminated eight-rod piezoelectric stator is shown in figures 1-5 and comprises a stator assembly 1, a positioning platform 2 and a support assembly 3, and is characterized in that: the stator assembly 1 is connected with the support assembly 3 and is arranged in the positioning platform 2, the positioning platform 2 is connected with the stator assembly 1 and the support assembly 3, and a moving pair is formed between the stator assembly 1 and the support assembly 3, the stator assembly 1 comprises a high-performance PZT piezoelectric ceramic sheet 12, a stator base 11 made of metal elastic material, and a driving foot 13 made of wear-resistant material, the stator base 11 comprises a rectangular block 111 and eight square rod bodies 112 positioned at four corners of the front and back surfaces of the rectangular block 111, the rectangular block 111 and the square rod bodies 112 are of an integrated structure, wherein the four square rod bodies 112 positioned at the upper part of the rectangular block 111 form an upper layer body, the four square rod bodies 112 positioned at the lower part of the rectangular block 111 form a lower layer body, a through hole is drilled at the center of the upper surface of the rectangular block 111, so that the stator base 11 can pass through the hole to be installed on the, a groove is formed at the connecting end of the square rod body 112 and the rectangular block 111, and holes are drilled in the center of the square rod body 112, so that the rigidity of the square rod body 112 is reduced to increase the amplitude of working mode vibration of the stator; the piezoelectric ceramic plates 12 are rectangular thin plates, are adhered to the periphery of the same position of the square rod body 112 along the length direction and are divided into two groups, wherein the piezoelectric ceramic plates 12 adhered to the upper surface and the lower surface of the square rod body 112 are double-clamp bending vibration excitation ceramics, and the total number of the piezoelectric ceramic plates 12 adhered to the side surface of the square rod body 112 is sixteen, and the total number of the piezoelectric ceramic plates 12 is sixteen; the driving feet 13 are in a cuboid shape, eight pieces are arranged at the rod end positions of the upper surface and the lower surface of the stator base 11, and in order to avoid movement interference, the height of the driving feet 13 needs to be larger than the thickness of the piezoelectric ceramic plate 12. The positioning platform 2 comprises a lower plate 21, an upper plate 22 and four upright posts 23, wherein the lower plate 21 and the upper plate 22 are rectangular plates, the peripheral sizes of the lower plate 21 and the upper plate 22 are the same, a square groove is formed in the middle of the lower plate 21 so that a boss 311 can penetrate through the lower plate 21 to facilitate installation of the stator base body 11, the upright posts 23 are in a square strip shape, one ends of the upright posts 23 are fastened with the lower plate 21 through platform screws 24, the other ends of the upright posts are fixed on the upper plate 22 through the platform screws 24, and elastic gaskets 25 are pressed between the upright posts 23 and the upper plate 22; the support assembly 3 comprises a bottom plate 31 and guide rail strips 32, wherein a boss 311 is arranged at the center of the bottom plate 31, a threaded hole is formed in the boss 311 for fixing the stator assembly 1, the cross section of each guide rail strip 32 is concave, the two guide rail strips 32 are fastened on the bottom plate 31 through screws 34, a guide rail elastic gasket 35 is arranged at the joint of each guide rail strip 32 and the bottom plate 31, the two guide rail strips 32 are parallel to each other and the grooves of the two guide rail strips are opposite, and mounting screws 33 are arranged at four corners of the bottom plate 31; the lower plate 21 of the positioning platform 2 is connected with the guide rail strip 32 of the support component 3 and forms a moving pair; the stator assembly 1 is arranged between the lower plate 21 and the upper plate 22 and is connected to a boss 311 on the support assembly 3 through a screw; four driving feet 13 on the upper layer body of the stator assembly 1 are connected with the lower surface of the upper layer plate 22, and four driving feet 13 on the lower layer body are connected with the upper surface of the lower layer plate 21; the pre-pressure between the positioning platform 2 and the stator assembly 1 can be adjusted by adjusting the degree of compression of the elastic gasket 25.

The working modes of the linear motor pushed by the laminated eight-rod piezoelectric stator are as follows: as shown in fig. 6 and 7, the dual integral sign mode includes a dual integral sign mode in which the square rod 112 of the stator assembly 1 vibrates reciprocally in the horizontal direction based on the plane of the layer body, and a dual clamp mode in which the square rod vibrates reciprocally in the positive and negative directions perpendicular to the plane of the layer body, where the dual integral sign mode indicates that the vibration of the stator only occurs in the plane of the upper layer body and the lower layer body, and the bending forms of the two vertical rods of each layer body are completely consistent; the double-clamp pincerlike mode means that the vibration of the stator is generated outside the plane where the two layers of bodies are located, and the bending forms of the upper part and the lower part of each vertical rod of the two-layer body structure are just opposite. The dual clamp mode is used for alternately keeping the driving feet 13 in contact with or separated from the positioning platform 2, and the dual integrating symbol mode is used for alternately pushing the positioning platform 2 to move by the driving feet 13.

The operation mode of the linear motor driven by the laminated eight-rod piezoelectric stator is as follows: as shown in fig. 6 to 10, a specific dual integrator shape mode and a double clamp shape mode of the stator assembly 1 are excited based on the inverse piezoelectric effect of the piezoelectric ceramic plate 12, and the specific dual integrator shape mode and the double clamp shape mode of the stator assembly 1 are further utilized to push the positioning platform 2 to operate; when the equal amplitude, the same frequency and the time phase difference of 90 are respectively applied to the dual integral sign bending vibration excitation ceramic and the dual-clamp bending vibration excitation ceramic^oWhen the two-phase alternating current power signal excites the two-phase working mode, the dual-integral conformal mode vibration and the dual-clamp pincer mode vibration two-phase elastic vibration are simultaneously excited on the stator assembly 1. Homogeneous phase difference 90 in time and space due to two-phase vibration^oAnd the phases are linearly superposed through the stator assembly 1, so that mass points on the driving feet 13 at the ends of the square rod bodies 112 generate elliptical motion tracks. The laminated eight-bar piezoelectric stator utilizes the elliptical motion and pushes the positioning platform 2 to do linear motion by means of the friction coupling process between the driving foot 13 and the positioning platform 2. When the phase difference between electric power signals applied to the double integrator bend-excited ceramic and the double-clamp bend-excited ceramic becomes-90^oWhen the positioning platform 2 moves linearly, the direction of the elliptical motion trajectory of the mass point of the driving foot 13 changes, so that the positioning platform 2 moves linearly in the opposite direction.

As shown in fig. 8 and 9, in order to excite the dual integrator bending mode effectively and correctly, reasonable polarization and power supply configuration are required to be performed on the dual integrator bending vibration excitation ceramic, wherein "+" indicates that the piezoelectric polarization direction is perpendicular to the pasting surface and faces away from the square rod 112 in the same direction as the normal direction, and "-" indicates that the piezoelectric polarization direction is perpendicular to the pasting surface and faces toward the square rod 112 in the opposite direction to the normal direction; therefore, the requirements are as follows: the piezoelectric ceramic plates 12 adhered to the left surfaces of the four square rod bodies 112 on the back surface of the rectangular block 111 are all vertical to the adhering surface and are polarized in the direction opposite to the square rod bodies 112 in the same direction with the normal line, and the piezoelectric ceramic plates 12 on the right surfaces are all vertical to the adhering surfaceThe surface and the direction opposite to the normal direction and pointing to the direction of the square rod body 112 are polarized, the piezoelectric ceramic pieces 12 on the left surfaces of the four square rod bodies 112 pasted on the front surface of the rectangular block 111 are all vertical to the pasting surface and point to the direction of the square rod body 112 and are polarized opposite to the normal direction, and the piezoelectric ceramic pieces 12 on the right surfaces are all vertical to the pasting surface and are polarized in the direction opposite to the direction of the square rod body 112 and the normal direction; the same frequency cosine excitation voltage is introduced to the surfaces of all the dual integral sign bending vibration excitation ceramics

(ii) a Meanwhile, the adhesion surfaces of the double integral sign bending vibration excitation ceramic and the square rod body 112 are required to be grounded and connected with zero excitation voltage; in order to effectively and correctly excite the double-clamp mode, reasonable polarization and power supply configuration are required to be carried out on the double-clamp bending vibration excitation ceramic, and therefore the requirements are as follows: the piezoelectric ceramic plates 12 adhered to the upper surface of the square rod body 112 on the upper layer and positioned on the rear surface of the rectangular block 111 are all vertical to the adhering surface and are polarized in the direction opposite to the direction of the square rod body 112 in the same direction as the normal line, the piezoelectric ceramic plates 12 on the lower surface are all vertical to the adhering surface and are polarized in the direction opposite to the direction of the normal line and towards the direction of the square rod body 112, the piezoelectric ceramic plates 12 adhered to the upper surface of the square rod body 112 on the upper layer and positioned on the front surface of the rectangular block 111 are all vertical to the adhering surface and are polarized in the direction opposite to the direction of the square rod body 112 in the opposite direction to the direction of the normal line, and the piezoelectric; the polarization direction of the double-clamp bending vibration ceramic pasted on the surface of the lower layer body square rod body 112 is correspondingly opposite to the polarization direction of the double-clamp bending vibration excitation ceramic pasted on the surface of the upper layer body square rod body 112; the surfaces of all the double-clamp bending vibration excitation ceramics are connected with same-frequency sine excitation voltage

Meanwhile, the adhesion surfaces of the double-clamp bending vibration excitation ceramic and the square rod body 112 are required to be grounded and connected with zero excitation voltage. As shown in fig. 10, the inverse piezoelectric effect of the dual integrator bend-vibration excitation ceramic and the dual-clamp bend-vibration excitation ceramic is utilized, and the dual-integrator bend-vibration excitation ceramic and the dual-clamp bend-vibration excitation ceramic are further excited by the inverse piezoelectric effectCeramic applied constant amplitude, same frequency and time phase difference of 90^oThe two-phase alternating current power signal excites the two-phase working mode, double integral conformal mode vibration and double clamp mode vibration two-phase elastic vibration are simultaneously excited on the stator assembly 1, and resonance or near resonance of the two-phase working mode drives mass points on the driving foot 13 arranged at the end part of the square rod body 112 to do elliptic motion; the laminated eight-rod piezoelectric stator utilizes the elliptic motion and pushes the positioning platform 2 to do linear motion by virtue of the friction coupling action between the driving foot 13 and the positioning platform 2; by changing the phase difference of two excitation signals to-90^oWhen the positioning platform 2 moves in the opposite direction, the elliptical motion direction of the mass point on the driving foot 13 can be changed.

The foregoing is a more detailed description of the present invention, taken in conjunction with the specific preferred embodiments thereof, and it is not intended that the invention be limited to the specific embodiments shown and described. For those skilled in the art to which the invention pertains, equivalent substitutes or obvious modifications may be made without departing from the spirit of the invention, and the same properties or uses are deemed to fall within the scope of the invention as defined by the claims appended hereto.

Claims

1. The utility model provides a linear electric motor that eight pole type piezoelectricity stators of stromatolite promoted, includes stator module (1), location platform (2) and support subassembly (3), its characterized in that: the stator assembly (1) is connected with the support assembly (3) and is arranged in the positioning platform (2), the positioning platform (2) is connected with the stator assembly (1) and the support assembly (3) and forms a sliding pair with the support assembly (3), the stator assembly (1) comprises a stator base body (11), a piezoelectric ceramic piece (12) and a driving foot (13), the stator base body (11) comprises a rectangular block (111) and eight square rod bodies (112) positioned at four corners of the front surface and the rear surface of the rectangular block (111), the rectangular block (111) and the square rod bodies (112) are of an integrated structure, wherein the four square rod bodies (112) positioned at the upper part of the rectangular block (111) form an upper layer body, the four square rod bodies (112) positioned at the lower part of the rectangular block (111) form a lower layer body, and a through hole is drilled at the center of the upper surface of the rectangular block (111), the stator base body (11) penetrates through the hole by a screw to be installed on the support assembly (3), a groove is formed in the connecting end of the square rod body (112) and the rectangular block (111), holes are drilled in the center of the square rod body (112), and the purpose of reducing the rigidity of the square rod body (112) to increase the amplitude of working mode vibration of the stator is achieved; the piezoelectric ceramic plates (12) are rectangular thin plate-shaped, are pasted on the periphery of the same position of the square rod body (112) along the length direction and are divided into two groups, wherein the piezoelectric ceramic plates (12) pasted on the upper surface and the lower surface of the square rod body (112) are double-clamp bending vibration excitation ceramic, the piezoelectric ceramic plates (12) pasted on the side surfaces of the square rod body (112) are double-integrator bending vibration excitation ceramic, and the driving feet (13) are cuboid and are arranged at the rod end positions of the upper surface and the lower surface of the stator base body (11).

2. The laminated eight-bar piezoelectric stator-propelled linear motor of claim 1, wherein: the positioning platform (2) comprises a lower plate (21), an upper plate (22) and four upright posts (23), wherein the lower plate (21) and the upper plate (22) are rectangular plates, the peripheral sizes of the lower plate and the upper plate are the same, a square groove is formed in the middle of the lower plate (21), the upright posts (23) are square strips, one ends of the upright posts are fastened with the lower plate (21) through platform screws (24), the other ends of the upright posts are fixed on the upper plate (22) through the platform screws (24), and elastic gaskets (25) are pressed between the upright posts (23) and the upper plate (22); the support assembly (3) comprises a bottom plate (31) and guide rail strips (32), wherein a boss (311) is installed at the center of the bottom plate (31), a threaded hole is formed in the boss (311), the cross sections of the guide rail strips (32) are concave, the two guide rail strips (32) are fastened on the bottom plate (31) through screws (34), guide rail elastic gaskets (35) are arranged at the joints of the guide rail strips (32) and the bottom plate (31), the two guide rail strips (32) are parallel to each other and are opposite in groove, and mounting screws (33) are arranged at four corners of the bottom plate (31); the lower layer plate (21) of the positioning platform (2) is connected with a guide rail bar (32) of the support assembly (3) and forms a moving pair; the stator assembly (1) is arranged between the lower layer plate (21) and the upper layer plate (22) and is connected to a boss (311) on the support assembly (3) through a screw; four driving feet (13) on the upper layer body of the stator component (1) are connected with the lower surface of the upper layer plate (22), and four driving feet (13) on the lower layer body are connected with the upper surface of the lower layer plate (21); the pre-pressure between the positioning platform (2) and the stator assembly (1) can be adjusted by adjusting the pressing degree of the elastic gasket (25).

3. A laminated eight-bar piezoelectric stator-propelled linear motor as claimed in claim 1 or 2, wherein: the working modes of the motor comprise a double integral symbol mode and a double clamp mode of the stator assembly, the double integral symbol mode specifies that the vibration of the stator only occurs in the plane where the upper layer body and the lower layer body are located, and the bending forms of two vertical rods of each layer body are completely consistent; the double-clamp mode is that the vibration of the stator is generated outside the plane of the two layers of bodies, the bending forms of the upper part and the lower part of each vertical rod of the two-layer body structure are opposite, the double-clamp mode is used for realizing the alternative keeping of the driving feet (13) in contact with or separated from the positioning platform (2), and the double-integral-symbol mode is used for realizing the alternative pushing of the positioning platform (2) by the driving feet (13).