CN115395818A

CN115395818A - Piezoelectric driving device

Info

Publication number: CN115395818A
Application number: CN202211079913.8A
Authority: CN
Inventors: 龚威; 许良; 王振华; 彭仁强; 刘如德
Original assignee: Suzhou Yinguan Semiconductor Technology Co ltd; Shanghai Yinguan Semiconductor Technology Co Ltd
Current assignee: Suzhou Yinguan Semiconductor Technology Co ltd; Shanghai Yinguan Semiconductor Technology Co Ltd
Priority date: 2022-09-05
Filing date: 2022-09-05
Publication date: 2022-11-25

Abstract

The present invention provides a piezoelectric driving device, including: the two ends of the first elastic structure of the shell part are connected with the outer frame structure, and the two ends of the second elastic structure are connected with the outer frame structure; the piezoelectric driving part comprises a first piezoelectric stack group, a second piezoelectric stack group and a rotor, the rotor is positioned between the first piezoelectric stack group and the second piezoelectric stack group, the first piezoelectric stack group is connected with one side, facing the rotor, of the first elastic structure, and the second piezoelectric stack group is connected with one side, facing the rotor, of the second elastic structure; the first magnetic pre-tightening part is positioned on one side, away from the rotor, of the first elastic structure, and applies a first pre-tightening force towards the rotor to the first elastic structure through the action of magnetic force; and the second magnetic pre-tightening part is positioned on one side of the second elastic structure, which is deviated from the rotor, and applies a second pre-tightening force towards the rotor to the second elastic structure through the action of magnetic force. The proposal greatly improves the output actuating power of the piezoelectric driving device.

Description

Piezoelectric driving device

Technical Field

The invention relates to the technical field of precision motion platforms, in particular to a piezoelectric driving device.

Background

In the field of precision equipment, precision motion technology is a core technology of equipment systems and is always highly valued in the industry. In a precise motion platform, the importance of a driving device is needless to say, and along with the improvement of the stability and the positioning precision of the device by the precise motion platform, the application of piezoelectric materials in the driving device is more and more extensive.

In the conventional piezoelectric driving device, an elastic structure is used for prepressing action on a piezoelectric stack, so that the piezoelectric stack clamps a rotor, and the rigidity and the pretightening force of the elastic structure are particularly important. In the working process of the piezoelectric driving device, the piezoelectric stack generates regular reciprocating actions of contraction and expansion, so that the elastic structure vibrates violently in a micro amplitude, the piezoelectric driving device is influenced by the rigidity factor of the elastic structure, the elastic structure can generate high-frequency obvious numerical value change to the pretightening force of the piezoelectric stack, the pretightening force with the obvious numerical value change has a great limiting effect on improving the external output actuating force of the rotor, and meanwhile, due to the fact that the fluctuation amplitude of the pretightening force is large, vibration noise can be generated, and the problem that the vibration noise interferes with the external environment is caused. Therefore, how to further increase the external output power of the piezoelectric driving device is a key issue for research in the industry.

Disclosure of Invention

The invention provides a piezoelectric driving device, which aims to solve the problem that the output actuating force of a mover in a piezoelectric driving device in the prior art is difficult to greatly improve.

In order to solve the above problem, the present invention provides a piezoelectric driving device including: the shell part comprises an outer frame structure, a first elastic structure and a second elastic structure, wherein two ends of the first elastic structure are connected with the outer frame structure, and two ends of the second elastic structure are connected with the outer frame structure; the piezoelectric driving part comprises a first piezoelectric stack group, a second piezoelectric stack group and a rotor, the rotor is positioned between the first piezoelectric stack group and the second piezoelectric stack group, the first piezoelectric stack group is connected with one side, facing the rotor, of the first elastic structure, and the second piezoelectric stack group is connected with one side, facing the rotor, of the second elastic structure; the first magnetic pre-tightening part is positioned on one side, away from the rotor, of the first elastic structure and applies a first pre-tightening force towards the rotor to the first elastic structure through the action of magnetic force; and the second magnetic pre-tightening part is positioned on one side of the second elastic structure, which is deviated from the rotor, and applies a second pre-tightening force towards the rotor to the second elastic structure through the action of magnetic force.

Furthermore, the first magnetic pre-tightening part comprises a first magnet and a second magnet, the first magnet and the second magnet are arranged at intervals along the direction facing the rotor and repel each other, the first magnet is connected with the outer frame structure, the second magnet is connected with the first elastic structure, and the second magnet applies a first pre-tightening force to the first elastic structure through the repulsive force; the second magnetic pre-tightening part comprises a third magnet and a fourth magnet, the third magnet and the fourth magnet are arranged at intervals in the direction facing the rotor and mutually repel, the third magnet is connected with the outer frame structure, the fourth magnet is connected with the second elastic structure, and the fourth magnet applies second pre-tightening force to the second elastic structure through the repulsive force; the first elastic structure exerts a third pre-tightening force towards the rotor on the first piezoelectric stack group through self elastic deformation, and the third pre-tightening force is smaller than the first pre-tightening force; the second elastic structure exerts fourth pretightening force towards the rotor on the second piezoelectric stack group through self elastic deformation, and the fourth pretightening force is smaller than the second pretightening force.

Furthermore, the rotor is provided with a first surface and a second surface which are opposite, the first surface is parallel to the second surface, the first piezoelectric stack group is matched with the first surface, the second piezoelectric stack group is matched with the second surface, the first pretightening force and the second pretightening force are perpendicular to the first surface and are arranged in opposite directions, and the third pretightening force and the fourth pretightening force are perpendicular to the first surface and are arranged in opposite directions.

Further, the gap between the first magnet and the second magnet is 0.5mm to 1.5mm, and the gap between the third magnet and the fourth magnet is 0.5mm to 1.5mm.

Furthermore, the first magnet and the second magnet are both one, and the polarities of the two opposite ends of the first magnet and the second magnet are the same; or, the first magnets and the second magnets are both multiple, the multiple first magnets are arranged at intervals along the moving direction of the rotor, the multiple second magnets are arranged at intervals along the moving direction of the rotor, the polarities of the two opposite ends of the two adjacent first magnets are opposite, the polarities of the two opposite ends of the two adjacent second magnets are opposite, the multiple first magnets and the multiple second magnets are arranged in a one-to-one correspondence manner, and the polarities of the two opposite ends of the first magnets and the two opposite ends of the corresponding second magnets are the same.

Furthermore, the shell part is of an integral structure or a split structure, the first piezoelectric stack group and the second magnet are respectively adhered to two opposite sides of the first elastic structure, and the second piezoelectric stack group and the fourth magnet are respectively adhered to two opposite sides of the second elastic structure.

Or the first magnetic pre-tightening part comprises a first magnet, a fifth magnet and a second magnet which are sequentially arranged at intervals, the first magnet is connected with the outer frame structure, the second magnet is connected with the first elastic structure, one end of the fifth magnet is mutually repelled with the first magnet, the other end of the fifth magnet is mutually repelled with the second magnet, and the second magnet applies a first pre-tightening force to the first elastic structure through the repelled force; the second magnetic pre-tightening part comprises a third magnet, a sixth magnet and a fourth magnet which are sequentially arranged at intervals, the third magnet is connected with the outer frame structure, the fourth magnet is connected with the second elastic structure, one end of the sixth magnet is mutually repelled with the third magnet, the other end of the sixth magnet is mutually repelled with the fourth magnet, and the fourth magnet applies a second pre-tightening force to the second elastic structure through the repelled force.

Furthermore, the piezoelectric driving device is provided with a preset symmetry plane, the first piezoelectric stack group and the second piezoelectric stack group are symmetrically arranged relative to the symmetry plane, the first elastic structure and the second elastic structure are symmetrically arranged relative to the symmetry plane, and the first magnetic pre-tightening part and the second magnetic pre-tightening part are symmetrically arranged relative to the symmetry plane.

Further, first elastic construction includes the main part and two elastic pieces that set up respectively in the main part both sides, and two elastic pieces are connected with the frame structure respectively, and first piezoelectricity pile group is connected with the main part, and the thickness of main part is greater than the thickness of elastic piece, and the thickness of elastic piece is 0.1mm ~ 0.5mm, and second elastic construction is the same with the structure of first elastic construction.

Further, the frame structure includes the relative first side wall that sets up, second side wall and the relative first rigidity portion that sets up, the second rigidity portion, the one end of first side wall, the one end of second side wall, the one end of first elastic construction, the one end of second elastic construction all is connected with first rigidity portion, the other end of first side wall, the other end of second side wall, the other end of first elastic construction, the other end of second elastic construction all is connected with second rigidity portion, first magnetism pretension portion is located the region between first side wall and the first elastic construction, second magnetism pretension portion is located the region between second side wall and the second elastic construction.

Further, the first piezoelectric stack group comprises 4N piezoelectric ceramic stacks, where N is an integer greater than zero, the 4N piezoelectric ceramic stacks are distributed in a one-dimensional array or a two-dimensional array, and the second piezoelectric stack group and the first piezoelectric stack group have the same structure.

Further, the mover is made of a ceramic material; or the rotor comprises a substrate, a first ceramic piece and a second ceramic piece which are respectively arranged on two sides of the substrate, wherein the first ceramic piece is matched with the first piezoelectric stacking group, and the second ceramic piece is matched with the second piezoelectric stacking group; or the rotor comprises a substrate, a first ceramic coating and a second ceramic coating, wherein the first ceramic coating and the second ceramic coating are respectively arranged on two sides of the substrate, the first ceramic coating is matched with the first piezoelectric stack group, and the second ceramic coating is matched with the second piezoelectric stack group.

Furthermore, the shell part also comprises a stop block arranged on the outer frame structure, the stop block is positioned on one side of the elastic sheet facing the rotor, and a first digging groove is formed between the stop block and the elastic sheet; wherein, two flexure strips of first elastic construction all correspond and are provided with a dog.

Furthermore, two ends of the main body in the moving direction of the rotor are respectively provided with a second digging groove, the second digging grooves are positioned on one side, facing the rotor, of the elastic sheet, and the opening of each second digging groove faces the opening of one corresponding first digging groove.

In the scheme, at least a part of force of first pretightening force applied by the first magnetic pretightening part is transmitted to the first piezoelectric stack group through the first elastic structure, at least a part of force of second pretightening force applied by the second magnetic pretightening part is transmitted to the second piezoelectric stack group through the second elastic structure, and meanwhile, elastic deformation of the first elastic structure and the second elastic structure also applies pretightening force to the piezoelectric driving part, so that most of elastic pretightening force is replaced by magnetic force action. Specifically, the magnetic force is adopted in the scheme to improve the pretightening force, so that the pretightening force and pretightening rigidity requirements on the elastic structure are greatly reduced, and the change of the magnetic force in the micrometer amplitude range is extremely small, so that the pretightening force applied to the piezoelectric stacking group in the working process is very small, and the influence on the output performance is greatly reduced. In addition, the scheme greatly reduces the variation amplitude of the pretightening force, thereby reducing the vibration amplitude of the elastic structure and further reducing the vibration noise interference in the piezoelectric driving process. In addition, the magnetic pre-tightening part has certain energy storage characteristics and can store and release certain vibration energy, so that vibration and noise are further reduced.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this application, are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification, illustrate embodiment(s) of the invention and together with the description serve to explain the invention and not to limit the invention. In the drawings:

fig. 1 is a schematic structural diagram of a piezoelectric driving device according to an embodiment of the present invention;

fig. 2 shows a plan view of the piezo drive of fig. 1;

fig. 3 shows a schematic representation of the pretensioning principle of the piezo drive of fig. 1;

FIG. 4 illustrates a schematic view of the housing portion of FIG. 1;

fig. 5 shows a schematic structural view of the piezoelectric driving part in fig. 1;

fig. 6 is a schematic structural diagram of a piezoelectric driving device according to a second embodiment of the present invention;

fig. 7 is a schematic structural diagram of a piezoelectric driving device according to a third embodiment of the present invention;

fig. 8 shows a schematic structural diagram of the piezoelectric driving part in fig. 7.

Wherein the figures include the following reference numerals:

100. a housing portion; 110. an outer frame structure; 111. a first side wall; 112. a second side wall; 113. a first rigid section; 114. a second rigid portion; 120. a first elastic structure; 121. a main body; 122. an elastic sheet; 130. a second elastic structure; 140. a stopper; 151. first grooving; 152. second grooving;

200. a piezoelectric driving section; 210. a first piezo stack group; 211. stacking the piezoelectric ceramics; 220. a second piezo stack group; 230. a mover; 231. a first side; 232. a second face;

300. a first magnetic pre-tightening part; 310. a first magnet; 320. a second magnet;

400. a second magnetic pre-tightening part; 410. a third magnet; 420. and a fourth magnet.

Detailed Description

The technical solution in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. It should be apparent that the described embodiments are only some embodiments of the present invention, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the invention, its application, or uses. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

As shown in fig. 1 to 5, a first embodiment of the present invention provides a piezoelectric driving device, including: a housing portion 100, the housing portion 100 including an outer frame structure 110, a first elastic structure 120 and a second elastic structure 130, two ends of the first elastic structure 120 being connected to the outer frame structure 110, two ends of the second elastic structure 130 being connected to the outer frame structure 110; the piezoelectric driving unit 200 includes a first piezoelectric stack group 210, a second piezoelectric stack group 220, and a mover 230, wherein the mover 230 is located between the first piezoelectric stack group 210 and the second piezoelectric stack group 220, the first piezoelectric stack group 210 is connected to a side of the first elastic structure 120 facing the mover 230, and the second piezoelectric stack group 220 is connected to a side of the second elastic structure 130 facing the mover 230; the first magnetic pre-tightening part 300 is positioned on one side, away from the mover 230, of the first elastic structure 120, and the first magnetic pre-tightening part 300 exerts a first pre-tightening force towards the mover 230 on the first elastic structure 120 through the action of magnetic force; the second magnetic pre-tightening portion 400 is located on a side of the second elastic structure 130 away from the mover 230, and the second magnetic pre-tightening portion 400 exerts a second pre-tightening force on the second elastic structure 130 toward the mover 230 through a magnetic force. In fig. 1, X, Y, and Z represent three directions of a rectangular coordinate system, wherein the moving direction of the mover 230 is the X direction in the drawing.

In this scheme, at least a part of the force of the first pretightening force applied by the first magnetic pretightening part 300 is transmitted to the first piezoelectric stack group 210 through the first elastic structure 120, at least a part of the force of the second pretightening force applied by the second magnetic pretightening part 400 is transmitted to the second piezoelectric stack group 220 through the second elastic structure 130, and meanwhile, elastic deformation of the first elastic structure 120 and the second elastic structure 130 also applies a part of pretightening force to the piezoelectric driving part 200, so that the scheme replaces most of the existing elastic pretightening force through the action of magnetic force, and since the magnetic force stiffness is relatively small, the magnetic force can be designed to be large, thereby not only greatly improving the pretightening force of the piezoelectric stack group, but also obviously reducing the fluctuation amplitude of the pretightening force in the working process, and greatly improving the output actuating force of the piezoelectric driving device. The magnetic rigidity is the magnitude of the change value of the magnetic force corresponding to the unit displacement, and the smaller magnetic rigidity means that the force change value of the elastic pretightening force in the micrometer range is larger than the magnetic force change value.

Specifically, because the magnetic force is adopted in the scheme to improve the pretightening force, compared with the prior art, the pretightening force and pretightening stiffness requirements on the elastic structures (the first elastic structure 120 and the second elastic structure 130) are greatly reduced, and the change of the pretightening force received by the piezoelectric stack group in the working process is very small due to the extremely small change of the magnetic force in the micrometer amplitude range, so that the influence on the output performance is greatly reduced. In addition, the scheme greatly reduces the variation amplitude of the pretightening force, so that the vibration amplitude of the elastic structure is reduced, and the vibration noise interference in the piezoelectric driving process is further reduced. In addition, the magnetic pre-tightening parts (the first magnetic pre-tightening part 300 and the second magnetic pre-tightening part 400) have certain energy storage characteristics, and can store and release certain vibration energy, so that vibration and noise are further reduced.

As shown in fig. 2 and 3, the first magnetic pre-tightening part 300 includes a first magnet 310 and a second magnet 320, the first magnet 310 and the second magnet 320 are disposed at an interval in a direction (i.e., Y direction) toward the mover 230 and repel each other, the first magnet 310 is connected to the outer frame structure 110, the second magnet 320 is connected to the first elastic structure 120, and the second magnet 320 applies a first pre-tightening force to the first elastic structure 120 by the repulsive force. In this way, the outer frame structure 110 supports the first magnet 310, the first magnet 310 and the second magnet 320 repel each other, opposite ends of the first magnet 310 and the second magnet 320 have the same polarity, and the repulsive force applied to the second magnet 320 is applied to the first elastic structure 120, i.e., the first pre-tightening force is applied to the first elastic structure 120, and is transferred by the first elastic structure 120 and the first piezo stack 210, so that the pre-tightening force is applied to the mover 230. Correspondingly, the second magnetic pre-tightening portion 400 includes a third magnet 410 and a fourth magnet 420, opposite ends of the third magnet 410 and the fourth magnet 420 have the same polarity, the third magnet 410 and the fourth magnet 420 are disposed at intervals in a direction toward the mover 230 and repel each other, the third magnet 410 is connected to the outer frame structure 110, the fourth magnet 420 is connected to the second elastic structure 130, and the fourth magnet 420 exerts a second pre-tightening force on the second elastic structure 130 through the repulsive force, so that the pre-tightening force is exerted in both opposite directions of the mover 230, and the mover 230 is clamped.

In this embodiment, the first elastic structure 120 applies a third pre-tightening force to the first piezo stack group 210 through elastic deformation thereof, where the third pre-tightening force is smaller than the first pre-tightening force; the second elastic structure 130 exerts a fourth pre-tightening force on the second piezoelectric stack group 220 toward the mover 230 through elastic deformation of the second elastic structure, and the fourth pre-tightening force is smaller than the second pre-tightening force. The third pre-tightening force is generated by elastic deformation of the first elastic structure 120, and the fourth pre-tightening force is generated by elastic deformation of the second elastic structure 130, which can be understood as a light-pressure clamping force applied to the mover 230, so as to achieve a primary positioning effect on the mover 230. The first pre-tightening force and the second pre-tightening force can be understood as a heavy-pressure clamping force applied to the mover 230, and act as a clamping action on the mover 230.

In the prior art, during the operation process of the piezoelectric driving device outputting displacement along the X direction, the first piezoelectric stack group 210 and the second piezoelectric stack group 220 may generate reciprocating motions of contraction and expansion regularly along the Y direction, so as to cause the first elastic structure 120 and the second elastic structure 130 to vibrate violently at micron level along the Y direction. Because the two elastic structures in this embodiment are only used to provide a light-pressure clamping force for preliminary clamping and positioning of the mover 230, and the requirements on the pre-tightening force and the pre-tightening stiffness are low, in the working process, the elastic deformation force generated by the elastic structures is controlled within a relatively small fluctuation range, and the vibration noise is greatly reduced. In addition, since there is no contact between the magnets of the first and

second magnets

310 and 320 providing the heavy clamping force and the repulsive force is less rigid, the variation of the repulsive force generated by the magnets is also controlled within a relatively small fluctuation range. Therefore, on one hand, the clamping force on the rotor 230 of the piezoelectric driving device is improved, so that the external output actuating force of the piezoelectric driving device is greatly improved, on the other hand, the fluctuation amplitude of the clamping force on the rotor 230 is reduced, the interference of vibration noise to the external environment is obviously weakened, and the adverse effect of the fluctuation of the clamping force on the output performance of the piezoelectric driving device is reduced.

As shown in fig. 5, the mover 230 has a first surface 231 and a second surface 232 which are opposite to each other, the first surface 231 and the second surface 232 are parallel to each other, the first piezo stack group 210 is matched with the first surface 231, the second piezo stack group 220 is matched with the second surface 232, the first pretightening force and the second pretightening force are perpendicular to the first surface 231 and are opposite to each other, and the third pretightening force and the fourth pretightening force are perpendicular to the first surface 231 and are opposite to each other. Thus, the first preload force and the third preload force are both directed toward the first surface 231 of the mover 230, thereby providing a clamping force to the mover 230 in a direction toward the first surface 231, and the second preload force and the fourth preload force are both directed toward the second surface 232 of the mover 230, thereby providing a clamping force to the mover 230 in a direction toward the second surface 232. The moving direction of the mover 230 is parallel to the first surface 231 and the second surface 232, which increases the clamping force on the mover 230 and improves the output actuation power of the piezoelectric driving device.

It should be noted that all numerical ranges recited in the present embodiment include two endpoints.

In the present embodiment, the gap between the first and

second magnets

310 and 320 is 0.5 to 1.5mm, and the gap between the third and

fourth magnets

410 and 420 is 0.5 to 1.5mm. By setting the gap between the first magnet 310 and the second magnet 320 and the gap between the third magnet 410 and the fourth magnet 420 in the above ranges, the repulsive force generated between the first magnet 310 and the second magnet 320, the repulsive force between the third magnet 410 and the fourth magnet 420 are relatively large, and the rigidity of the repulsive force is relatively small, so that the pre-tightening force of the piezoelectric stack group can be greatly improved, the fluctuation amplitude of the pre-tightening force in the working process can be obviously reduced, and the output actuating force of the piezoelectric driving device is improved. The specific value of the gap is selected according to the requirement of output power, the volume size of the magnet and the like.

In this embodiment, the housing portion 100 is an integral structure or a separate structure, which can be selected according to the production requirement. The first piezo stack group 210 and the second magnet 320 are respectively adhered to two opposite sides of the first elastic structure 120, and the second piezo stack group 220 and the fourth magnet 420 are respectively adhered to two opposite sides of the second elastic structure 130, so that the adhering manner is adopted, the assembling is convenient, and the structure is compact.

In this embodiment, the piezoelectric driving device has a predetermined symmetry plane, the first piezoelectric stack group 210 and the second piezoelectric stack group 220 are symmetrically disposed with respect to the symmetry plane, the first elastic structure 120 and the second elastic structure 130 are symmetrically disposed with respect to the symmetry plane, and the first magnetic pre-tightening part 300 and the second magnetic pre-tightening part 400 are symmetrically disposed with respect to the symmetry plane. Therefore, the piezoelectric driving device is integrally of a symmetrical structure, so that on one hand, the manufacturing and the assembly are convenient, on the other hand, the symmetry of the clamping force of the two piezoelectric stack groups on the mover 230 is easily realized, and the stability of the mover 230 during movement is ensured.

As shown in fig. 2 to 4, the first elastic structure 120 includes a main body 121 and two elastic pieces 122 respectively disposed at two sides of the main body 121, the two elastic pieces 122 are respectively connected with the outer frame structure 110, the first piezo stack group 210 is connected with the main body 121, the thickness of the main body 121 is greater than that of the elastic pieces 122, the thickness of the elastic pieces 122 is 0.1mm to 0.5mm, and the second elastic structure 130 and the first elastic structure 120 have the same structure. With the above arrangement, the main body 121 supports the first piezo stack group 210, and a pretightening force is applied to the first piezo stack group 210 by an acting force generated by elastic deformation of the elastic sheet 122. Specifically, the body 121 is preferably made of a rigid material, one surface of the body 121 is bonded with the magnet, and the other surface is bonded with the piezoelectric stack assembly, and the rigidity of the body 121 facilitates bonding and positioning. Wherein the thickness of the elastic sheet 122 is preferably 0.3mm.

As shown in fig. 4, the outer frame structure 110 includes a first side wall 111, a second side wall 112, a first rigid portion 113 and a second rigid portion 114, the first side wall 111, the second side wall 112, the first elastic structure 120, and the second elastic structure 130 are connected to the first rigid portion 113, the first side wall 111, the second side wall 112, the first elastic structure 120, and the second elastic structure 130 are connected to the second rigid portion 114, the first magnetic pre-tightening part 300 is located in a region between the first side wall 111 and the first elastic structure 120, and the second magnetic pre-tightening part 400 is located in a region between the second side wall 112 and the second elastic structure 130. The first rigid portion 113 and the second rigid portion 114 provide support for the first elastic structure 120 and the second elastic structure 130, the first sidewall 111 provides support for the first magnetic prefastening portion 300, and the second sidewall 112 provides support for the second magnetic prefastening portion 400. The first side wall 111 and the second side wall 112 are preferably made of a rigid material, so that the rigid walls can ensure that the two magnetic pretensions exert a larger positive pressure on the mover 230.

In the present embodiment, the mover 230 is made of a ceramic material; or, the mover 230 includes a base, and a first ceramic sheet and a second ceramic sheet respectively disposed at two sides of the base, where the first ceramic sheet is matched with the first piezo stack group 210, and the second ceramic sheet is matched with the second piezo stack group 220; or, the mover 230 includes a base, and a first ceramic coating and a second ceramic coating respectively disposed on two sides of the base, where the first ceramic coating is matched with the first piezo stack group 210, and the second ceramic coating is matched with the second piezo stack group 220. With the arrangement, the mover 230 has high rigidity, good wear resistance and long service life. The ceramic material may be alumina ceramic, silicon carbide ceramic, zirconia ceramic, or the like.

As shown in fig. 3 and 4, the housing portion 100 further includes a stopper 140 disposed on the outer frame structure 110, the stopper 140 is disposed on a side of the elastic piece 122 facing the mover 230, and a first cutout 151 is formed between the stopper 140 and the elastic piece 122; the two elastic pieces 122 of the first elastic structure 120 are respectively provided with a stop 140. The first cutout 151 and the stopper 140 are provided to prevent the elastic piece 122 from being broken due to an unpredictable external force applied to the piezoelectric driving unit. Specifically, under the action of external force, the elastic piece 122 may have an excessively large swing amplitude, which is likely to break, and the arrangement of the stopper 140 may provide a stopping and limiting effect for the elastic piece 122, so as to prevent the elastic piece 122 from having an excessively large swing amplitude, thereby preventing the elastic piece 122 from breaking.

Optionally, both ends of the main body 121 along the moving direction of the mover 230 have a second slot 152, the second slot 152 is located on a side of the elastic sheet 122 facing the mover 230, and an opening of each second slot 152 faces an opening of a corresponding first slot 151. The second grooves 152 are designed to meet the length requirement of the elastic piece 122, and if the length of the first grooves 151 is limited by the structure and cannot meet the requirement, the second grooves 152 can be correspondingly added, so that the elastic piece 122 meets the length requirement through the arrangement of the second grooves 152.

In the present embodiment, the first magnet 310 and the second magnet 320 are both one, and the polarities of the two opposite ends of the first magnet 310 and the second magnet 320 are the same; accordingly, each of the third and

fourth magnets

410 and 420 is one, and the polarities of the opposite ends of the third and

fourth magnets

410 and 420 are the same.

As shown in fig. 6, in the second embodiment, different from the first embodiment, the first magnet 310 and the second magnet 320 are both provided in plural, the plural first magnets 310 are arranged at intervals along the moving direction of the mover 230, the plural second magnets 320 are arranged at intervals along the moving direction of the mover 230, the polarities of the opposite ends of two adjacent first magnets 310 are opposite, the polarities of the opposite ends of two adjacent second magnets 320 are opposite, the plural first magnets 310 and the plural second magnets 320 are arranged in one-to-one correspondence, and the polarities of the opposite ends of the first magnets 310 and the corresponding second magnets 320 are the same. The first magnet 310 and the second magnet 320 are provided in plurality, so that the magnetic induction line density around the magnets is increased, and under the condition of a certain space size range, the repulsion force between the magnets is obtained as much as possible. And, two adjacent first magnets 310 attract each other, and two adjacent second magnets 320 attract each other, so that the larger component of the two mutually attracting forces in the moving direction of the mover 230 are cancelled out, and the smaller component of the two mutually attracting forces in the direction toward the mover 230 is cancelled out by a part of the repulsive force between the magnets, thereby improving the stability of the force balance of the first elastic structure 120 in the moving direction of the mover 230, and reducing the adverse effect caused by the reduction of the pre-tightening stiffness of the first elastic structure 120. Accordingly, in the second embodiment, the third magnet 410 and the fourth magnet 420 are also provided in plural numbers, and the third magnet 410 and the fourth magnet 420 are arranged in the same direction as the first magnet 310 and the second magnet 320, so that the same advantageous effects can be produced.

In this embodiment, the first piezo stack group 210 includes 4N piezo ceramic stacks 211, where N is an integer greater than zero, the 4N piezo ceramic stacks 211 are distributed in a one-dimensional array or a two-dimensional array, and the second piezo stack group 220 and the first piezo stack group 210 have the same structure. For example, in the first and second embodiments, the first piezo stack group 210 includes 4 piezo ceramic stacks 211, and the 4 piezo ceramic stacks 211 are distributed in a one-dimensional array. As shown in fig. 7 and 8, in the third embodiment, unlike the first embodiment, 4 piezoelectric ceramic stacks 211 are distributed in a two-dimensional array, which can also meet the use requirement.

Specifically, each piezoelectric ceramic stack 211 includes two portions, the polarization directions of the ceramic structures of the two portions are different, the polarization direction of the ceramic structure of one portion is along the axial direction (Y direction in fig. 1) and provides the expansion deformation in the axial direction, and the polarization direction of the ceramic structure of the other portion is along the tangential direction and provides the deflection deformation in the tangential direction (X direction in fig. 1); from the view of the single-side piezoelectric stack group, the piezoelectric ceramic stack 211 extends out along the axial direction to clamp the mover 230, the piezoelectric ceramic stack 211 clamps the mover 230 under the positive pressure of the pre-tightening mechanism, and generates a static friction force on a contact surface, the static friction force provides a force required by the movement of the mover 230 in the forward direction, and then the piezoelectric ceramic stack 211 swings along the tangential direction to drive the mover 230 to move forward for a certain displacement; in order to realize the continuous movement of the rotor 230, the single-side 4N piezoceramic stacks 211 are divided into two groups, one group is responsible for clamping and deflecting to drive the rotor 230 to move, the other group is responsible for disengaging and resetting, after the former group moves in place or approaches to be in place, the latter group extends to clamp and deflect to drive the rotor 230 to move, and simultaneously the former group disengages and resets, so that the operation flow is circularly performed, and the two groups alternately perform the operations of clamping, deflecting, disengaging and resetting, thereby realizing the continuous movement of the rotor 230.

In a fourth embodiment not shown in the drawings, the first magnetic pre-tightening part 300 includes a first magnet 310, a fifth magnet and a second magnet 320 which are sequentially arranged at intervals in a direction toward the mover 230, a first end of the first magnet 310 is connected with the outer frame structure 110, a first end of the second magnet 320 is connected with the first elastic structure 120, a first end of the fifth magnet is the same polarity as a second end of the first magnet 310, and the first and second magnets repel each other; the second end of the fifth magnet and the second end of the second magnet 320 have the same polarity, and the second ends repel each other; the second magnet 320 applies a first pre-tightening force to the first elastic structure 120 through the received repulsive force; the second magnetic pre-tightening part 400 includes a third magnet 410, a sixth magnet and a fourth magnet 420 which are sequentially arranged along the direction facing the mover 230 at intervals, a first end of the third magnet 410 is connected with the outer frame structure 110, and a first end of the fourth magnet 420 is connected with the second elastic structure 130; the first end of the sixth magnet and the second end of the third magnet 410 are of the same polarity and are mutually repulsive; the second end of the sixth magnet and the second end of the fourth magnet 420 have the same polarity, and are mutually repulsive; the fourth magnet 420 exerts a second pre-load force on the second elastic structure 130 through the repulsive force.

Compared with the first embodiment, in the present embodiment, a row of magnets is added in the Y direction on each side of the mover 230, so that the fifth magnet and the sixth magnet perform a better vibration buffering function (similar to the energy storage and inertia of the flywheel) during the regular reciprocating motion of the piezoelectric stack group in the Y direction, which contracts and expands.

Through the scheme, the problem of bottleneck in lifting the output actuating force of the mover of the medium-voltage driving device in the prior art can be solved, and the pre-tightening force of the piezoelectric ceramic stack is improved through the repulsive force of the magnet, so that the output actuating force of the piezoelectric driving device is greatly improved.

Moreover, the invention can solve the problem that the output performance of the medium-voltage electric driving device is greatly influenced by the large variation of the pretightening force of the elastic mechanism in the prior art, the pretightening force is improved by using the repulsive force of the magnet, so the requirements on the pretightening force and the pretightening rigidity of the elastic mechanism are greatly reduced, and the output performance is greatly reduced because the repulsive force of the magnet varies slightly in the micrometer range, so the pretightening force variation of the piezoelectric ceramic stack in the working process is small.

In addition, the invention can solve the problem of vibration noise interference in the working process of the piezoelectric driving device in the prior art, and the repulsive force of the magnet is used for replacing most of the pretightening force of the elastic mechanism, so that the change amplitude of the pretightening force is greatly reduced, the vibration amplitude is reduced, and the vibration noise interference in the piezoelectric driving process is reduced. In addition, the magnet has certain energy storage characteristics and can store and release certain vibration energy.

The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A piezoelectric driving apparatus, comprising:

the shell comprises a shell body (100), wherein the shell body (100) comprises an outer frame structure (110), a first elastic structure (120) and a second elastic structure (130), two ends of the first elastic structure (120) are connected with the outer frame structure (110), and two ends of the second elastic structure (130) are connected with the outer frame structure (110);

a piezoelectric driving part (200), wherein the piezoelectric driving part (200) comprises a first piezoelectric stack group (210), a second piezoelectric stack group (220) and a mover (230), the mover (230) is located between the first piezoelectric stack group (210) and the second piezoelectric stack group (220), the first piezoelectric stack group (210) and the first elastic structure (120) are connected towards one side of the mover (230), and the second piezoelectric stack group (220) and the second elastic structure (130) are connected towards one side of the mover (230);

the first magnetic pre-tightening part (300) is positioned on one side, away from the rotor (230), of the first elastic structure (120), and the first magnetic pre-tightening part (300) exerts a first pre-tightening force towards the rotor (230) on the first elastic structure (120) through the action of magnetic force;

the second magnetic pre-tightening part (400) is located on one side, away from the rotor (230), of the second elastic structure (130), and the second magnetic pre-tightening part (400) exerts a second pre-tightening force, facing the rotor (230), on the second elastic structure (130) through magnetic force.

2. Piezoelectric driving device according to claim 1,

the first magnetic pretightening part (300) comprises a first magnet (310) and a second magnet (320), the first magnet (310) and the second magnet (320) are arranged at intervals in the direction facing the mover (230) and repel each other, the first magnet (310) is connected with the outer frame structure (110), the second magnet (320) is connected with the first elastic structure (120), and the second magnet (320) applies the first pretightening force to the first elastic structure (120) through the repelled force;

the second magnetic pretightening part (400) comprises a third magnet (410) and a fourth magnet (420), the third magnet (410) and the fourth magnet (420) are arranged at intervals in the direction facing the rotor (230) and repel each other, the third magnet (410) is connected with the outer frame structure (110), the fourth magnet (420) is connected with the second elastic structure (130), and the fourth magnet (420) applies the second pretightening force to the second elastic structure (130) through the repulsive force;

the first elastic structure (120) exerts a third pre-tightening force towards the rotor (230) on the first piezoelectric stack group (210) through elastic deformation of the first elastic structure, and the third pre-tightening force is smaller than the first pre-tightening force;

the second elastic structure (130) exerts a fourth pre-tightening force on the second piezoelectric stack group (220) towards the rotor (230) through elastic deformation of the second elastic structure, and the fourth pre-tightening force is smaller than the second pre-tightening force.

3. The piezoelectric driving apparatus according to claim 2, wherein the mover (230) has a first surface (231) and a second surface (232) opposite to each other, the first surface (231) and the second surface (232) are parallel to each other, the first piezoelectric stack group (210) is engaged with the first surface (231), the second piezoelectric stack group (220) is engaged with the second surface (232), the first pre-tightening force and the second pre-tightening force are perpendicular to the first surface (231) and are oppositely disposed, and the third pre-tightening force and the fourth pre-tightening force are perpendicular to the first surface (231) and are oppositely disposed.

4. The piezoelectric driving device according to claim 2, wherein a gap between the first magnet (310) and the second magnet (320) is 0.5mm to 1.5mm, and a gap between the third magnet (410) and the fourth magnet (420) is 0.5mm to 1.5mm.

5. Piezoelectric driving device according to claim 2,

the first magnet (310) and the second magnet (320) are both one, and the polarities of the two opposite ends of the first magnet (310) and the second magnet (320) are the same; or the like, or, alternatively,

the first magnets (310) and the second magnets (320) are multiple, the multiple first magnets (310) are arranged at intervals along the moving direction of the mover (230), the multiple second magnets (320) are arranged at intervals along the moving direction of the mover (230), the two opposite ends of the two adjacent first magnets (310) are opposite in polarity, the two opposite ends of the two adjacent second magnets (320) are opposite in polarity, the multiple first magnets (310) and the multiple second magnets (320) are arranged in a one-to-one correspondence manner, and the two opposite ends of the first magnets (310) and the corresponding second magnets (320) are identical in polarity.

6. The piezoelectric driving apparatus according to claim 2, wherein the housing portion (100) is an integral structure or a separate structure, the first piezoelectric stack group (210) and the second magnet (320) are respectively adhered to two opposite sides of the first elastic structure (120), and the second piezoelectric stack group (220) and the fourth magnet (420) are respectively adhered to two opposite sides of the second elastic structure (130).

7. Piezoelectric driving device according to claim 1,

the first magnetic pretightening part (300) comprises a first magnet (310), a fifth magnet and a second magnet (320) which are sequentially arranged at intervals, wherein the first magnet (310) is connected with the outer frame structure (110), the second magnet (320) is connected with the first elastic structure (120), one end of the fifth magnet and the first magnet (310) repel each other, the other end of the fifth magnet and the second magnet (320) repel each other, and the second magnet (320) applies the first pretightening force to the first elastic structure (120) through the repulsive force;

the second magnetic pre-tightening part (400) comprises a third magnet (410), a sixth magnet and a fourth magnet (420) which are sequentially arranged at intervals, the third magnet (410) is connected with the outer frame structure (110), the fourth magnet (420) is connected with the second elastic structure (130), one end of the sixth magnet and the third magnet (410) repel each other, the other end of the sixth magnet and the fourth magnet (420) repel each other, and the fourth magnet (420) applies the second pre-tightening force to the second elastic structure (130) through the repulsive force.

8. The piezo-electric drive according to any one of claims 1 to 7, characterized in that the piezo-electric drive has a predetermined plane of symmetry, the first piezo stack group (210) and the second piezo stack group (220) being arranged symmetrically with respect to the plane of symmetry, the first spring structure (120) and the second spring structure (130) being arranged symmetrically with respect to the plane of symmetry, and the first magnetic pretension (300) and the second magnetic pretension (400) being arranged symmetrically with respect to the plane of symmetry.

9. The piezoelectric driving apparatus according to claim 1, wherein the first elastic structure (120) includes a main body (121) and two elastic pieces (122) respectively disposed at two sides of the main body (121), the two elastic pieces (122) are respectively connected to the outer frame structure (110), the first piezoelectric stack group (210) is connected to the main body (121), the thickness of the main body (121) is greater than that of the elastic pieces (122), the thickness of the elastic pieces (122) is 0.1mm to 0.5mm, and the second elastic structure (130) and the first elastic structure (120) have the same structure.

10. The piezoelectric driving apparatus according to claim 1, wherein the outer frame structure (110) comprises a first side wall (111) and a second side wall (112) which are opposite to each other, and a first rigid portion (113) and a second rigid portion (114) which are opposite to each other, one end of the first side wall (111), one end of the second side wall (112), one end of the first elastic structure (120), and one end of the second elastic structure (130) are connected to the first rigid portion (113), the other end of the first side wall (111), the other end of the second side wall (112), the other end of the first elastic structure (120), and the other end of the second elastic structure (130) are connected to the second rigid portion (114), the first magnetic pre-tightening portion (300) is located in a region between the first side wall (111) and the first elastic structure (120), and the second magnetic pre-tightening portion (400) is located in a region between the second side wall (112) and the second elastic structure (130).

11. The piezoelectric driving apparatus according to claim 1, wherein the first piezoelectric stack group (210) includes 4N piezoelectric ceramic stacks (211), N is an integer greater than zero, the 4N piezoelectric ceramic stacks (211) are distributed in a one-dimensional array or a two-dimensional array, and the second piezoelectric stack group (220) and the first piezoelectric stack group (210) have the same structure.

12. Piezoelectric driving device according to claim 1,

the mover (230) is made of a ceramic material; or the like, or a combination thereof,

the rotor (230) comprises a base body, a first ceramic piece and a second ceramic piece, wherein the first ceramic piece and the second ceramic piece are respectively arranged on two sides of the base body, the first ceramic piece is matched with the first piezoelectric stacking group (210), and the second ceramic piece is matched with the second piezoelectric stacking group (220); or the like, or, alternatively,

the rotor (230) comprises a base body, a first ceramic coating and a second ceramic coating, wherein the first ceramic coating and the second ceramic coating are respectively arranged on two sides of the base body, the first ceramic coating is matched with the first piezoelectric stack group (210), and the second ceramic coating is matched with the second piezoelectric stack group (220).

13. The piezoelectric driving apparatus according to claim 9, wherein the housing portion (100) further comprises a stopper (140) disposed on the outer frame structure (110), the stopper (140) is located on a side of the elastic piece (122) facing the mover (230), and a first cutout (151) is formed between the stopper (140) and the elastic piece (122); the two elastic pieces (122) of the first elastic structure (120) are respectively and correspondingly provided with one stop block (140).

14. The piezoelectric driving device according to claim 13, wherein the main body (121) has a second cutout (152) at each end along the moving direction of the mover (230), the second cutout (152) is located at a side of the elastic piece (122) facing the mover (230), and an opening of each second cutout (152) faces an opening of a corresponding first cutout (151).