Magnetic preload walking type piezoelectric actuator

Abstract

The invention discloses a magnetic preloading walking type piezoelectric actuator, which comprises a rack, a moving part and a magnetic preloading module, and is characterized in that the moving part is a magnetic component; the magnetic preloading module comprises two magnetic preloading assemblies arranged on the two sides of the moving part respectively, the magnetic preloading assemblies are movably arranged in the second direction relative to the rack, the second direction is perpendicular to the first direction, each magnetic preloading assembly comprises at least one magnetic module and at least one piezoelectric module, each piezoelectric module comprises at least two piezoelectric feet, and the piezoelectric feet are arranged on the two sides of the moving part. The magnetic module is configured to form a magnetic attraction force along the second direction with the moving part so as to enable the at least two piezoelectric feet to be in contact with the moving part, and the piezoelectric module is configured to drive the moving part to move along the first direction by alternately driving the at least two piezoelectric feet. According to the invention, through the negative stiffness characteristic of the magnetic preloading force provided by the magnetic module, adaptive assembly of the moving part and the piezoelectric module is realized, and the precision of displacement output is improved.

Description

Technical Field

[0001] The invention relates to the technical field of semiconductor production and detection precision equipment, in particular to a magnetic preloaded walking type piezoelectric actuator. Background Art

[0002] In the field of semiconductor production and testing equipment, there are strict requirements on the motion accuracy, reliability and service life of high-precision moving parts. Piezoelectric actuators convert electrical signals into displacement outputs through the inverse piezoelectric effect, which can meet the technical needs of high-precision moving parts in semiconductor production. At the same time, they have the advantages of adapting to vacuum, low heat consumption, fast response and large load, and are therefore widely valued. Piezoelectric actuators require large preload force clamping to achieve large stroke and high-precision displacement output. The existing technology uses a high-rigidity flexible hinge mechanism to provide preload force, but it is very difficult in structural design, material selection and assembly process, and it is difficult to ensure high-precision displacement output. Summary of the invention The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, the present invention provides a magnetic preload walking piezoelectric actuator, which uses magnetic force as a preload force to achieve adaptive assembly and ensure the accuracy of displacement output.

[0003] A magnetic preload walking piezoelectric actuator according to an embodiment of the present invention includes: Stand; A moving part, the moving part extends along a first direction and is movably disposed on the stand, and the moving part is a magnetic component; The magnetic preload module comprises two magnetic preload components respectively arranged on both sides of the moving part, the magnetic preload components are movably arranged relative to the stand along a second direction, the second direction is arranged perpendicular to the first direction, the magnetic preload components include at least one magnetic module and at least one piezoelectric module, the piezoelectric module includes at least two piezoelectric feet, the magnetic module is configured to form a magnetic attraction force along the second direction between the moving part so that at least the two piezoelectric feet are in contact with the moving part, and the piezoelectric module is configured to drive the moving part to move along the first direction by alternately driving at least the two piezoelectric feet.

[0004] The magnetic preload walking piezoelectric actuator according to the embodiment of the present invention has at least the following beneficial effects: when in use, the magnetic modules on both sides of the moving part form a magnetic attraction force with the moving part along the second direction, and the magnetic attraction force serves as a preload force of the piezoelectric module, so that the piezoelectric feet on both sides of the moving part contact with the moving part, and the moving part is clamped by the piezoelectric modules on both sides. The piezoelectric module drives the moving part to move along the first direction by alternately driving at least two piezoelectric feet. At this time, the magnetic module and the moving part do not have direct contact. The negative stiffness characteristics of the magnetic preload force provided by the magnetic module enable the moving part and the piezoelectric module to be adaptively assembled, and the accuracy of the displacement output is improved.

[0005] According to some embodiments of the present invention, the moving component includes a ferromagnetic metal strip extending along the first direction. The ferromagnetic metal strip is provided with first contact pieces on both sides facing the two magnetic preload components, and the piezoelectric foot is in contact with the first contact pieces.

[0006] In this solution, the moving part is set as a ferromagnetic metal strip, and the ferromagnetic metal strip is used to form a magnetic attraction with the magnetic module, which can increase the magnitude of the magnetic attraction and the magnitude of the preload force. Secondly, when the ferromagnetic metal strip moves along the first direction, the magnetic attraction is maintained between the magnetic module and the ferromagnetic metal strip, thereby generating a large stroke, continuous high-precision displacement output. The setting of the first contact piece can improve the wear resistance of the moving part, extend the service life of the moving part, and also improve the accuracy of the displacement output.

[0007] According to some embodiments of the present invention, the piezoelectric foot is provided with a second contact piece in contact with the first contact piece.

[0008] The piezoelectric foot in this solution contacts the first contact piece through the second contact piece, thereby improving the wear resistance of the piezoelectric foot and thus increasing the service life of the piezoelectric foot. At the same time, it also increases the friction between the piezoelectric foot and the moving part, further improving the accuracy of the displacement output.

[0009] According to some embodiments of the present invention, the piezoelectric foot comprises a tangential piezoelectric stack and a vertical piezoelectric stack sequentially connected along the second direction, and the vertical piezoelectric stack is configured to extend along the second direction under a first preset voltage so that the piezoelectric foot is pressed against the moving part, and to retract along the second direction under a second preset voltage so that the piezoelectric foot is separated from the moving part; The tangential piezoelectric stack is configured to extend along the first direction when a third preset voltage is applied so that the piezoelectric foot pushes the moving part to move along the first direction, and to retract along the first direction when a fourth preset voltage is applied so that the piezoelectric foot returns to its original position.

[0010] In this way, in the piezoelectric module, a first preset voltage is applied to the vertical piezoelectric stack of one of the piezoelectric feet, so that the vertical piezoelectric stack extends along the second direction so that the piezoelectric foot is pressed against the moving part, and a third preset voltage is applied to the tangential piezoelectric stack in the piezoelectric foot, so that the tangential piezoelectric stack extends along the first direction so that the piezoelectric foot pushes the moving part to move along the first direction; at this time, a second preset voltage is applied to the vertical piezoelectric stack of the other piezoelectric foot, so that the vertical piezoelectric stack retracts along the second direction so that the piezoelectric foot is separated from the moving part, and a fourth preset voltage is applied to the tangential piezoelectric stack in the piezoelectric foot so that it retracts along the first direction so that the piezoelectric foot returns to its original position, and then the voltages of the two piezoelectric feet are alternately controlled to achieve alternating contact and displacement output between the two piezoelectric feet and the moving part.

[0011] According to some embodiments of the present invention, a first connecting insulating sheet is provided between the tangential piezoelectric stack and the vertical piezoelectric stack, a second connecting insulating sheet for installation and fixation is provided at one end of the vertical piezoelectric stack away from the tangential piezoelectric stack, and one end of the tangential piezoelectric stack away from the vertical piezoelectric stack is in contact with the moving component.

[0012] In this solution, the vertical piezoelectric stack is used to push the tangential piezoelectric stack to move in the second direction, so that the tangential piezoelectric stack is in contact with or separated from the moving part, while the tangential piezoelectric stacks are in contact with the moving part and push it to move in the first direction.

[0013] According to some embodiments of the present invention, a plurality of magnetic modules spaced apart along the first direction are respectively disposed on both sides of the moving component, and a piezoelectric module is disposed between two adjacent magnetic modules.

[0014] In this solution, magnetic modules are provided at both ends of the piezoelectric module, so that preload force is formed at both ends of the piezoelectric module, so that the contact between the piezoelectric foot on the piezoelectric module and the moving part is more uniform, and the actuating force is also improved.

[0015] According to some embodiments of the present invention, the magnetic module includes a plurality of magnets, and the plurality of magnets are periodically arranged in a Halbach array along the first direction and the second direction.

[0016] The magnetic module of the present invention is composed of magnets periodically arranged in a Halbach array along a first direction and a second direction. The magnetic field direction of each magnet is perpendicular to the magnetic field direction of the adjacent magnet. The magnetic fields are alternately arranged along the first direction and the second direction. The generated strong magnetic surface faces the moving part, which can further increase the size of the preload force.

[0017] According to some embodiments of the present invention, mounting beams extending along the first direction are respectively provided on both sides of the moving component, and flexible connecting members are respectively provided at both ends of the mounting beams. The mounting beams are connected to the stand through the flexible connecting members so that the mounting beams can move relative to the stand along the second direction, and the two magnetic preload assemblies are respectively installed on the two mounting beams.

[0018] The two ends of the mounting beam of the present invention are connected to the stand by flexible connectors, so that the movement of the mounting beam is constrained in the second direction and movement in other directions is restricted. When a magnetic attraction force is formed between the magnetic preload assembly and the moving part, the mounting beam approaches the moving part along the second direction.

[0019] According to some embodiments of the present invention, the magnetic preload assembly includes a back iron plate, the magnetic module and the piezoelectric module are detachably mounted on the inner side of the back iron plate, and the back iron plate is detachably mounted on the inner side of the mounting beam.

[0020] When in use, the magnetic module and the piezoelectric module can be removed one by one from the back iron plate for maintenance, and the back iron plate can be removed from the mounting beam to achieve modular assembly, which is easy to assemble.

[0021] According to some embodiments of the present invention, a guide rail and slider structure is provided between the moving component and the stand, and the guide rail and slider structure is used to limit the movement of the moving component in the first direction.

[0022] This solution constrains the movement of the moving parts in the first direction through the guide rail slider structure, and generates a large stroke and high-precision displacement output when clamped and pushed by the magnetic preload module.

[0023] Other features and advantages of the present invention will be set forth in the description which follows, and in part will be apparent from the description, or may be learned by practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The present invention will be further described below with reference to the accompanying drawings and embodiments, wherein: Figure 1 Schematic diagram of the structure of a magnetic preload walking piezoelectric actuator according to an embodiment of the present invention; Figure 2 A top view of a magnetic preloaded walking piezoelectric actuator according to an embodiment of the present invention; Figure 3 A side view of a magnetic preloaded walking piezoelectric actuator according to an embodiment of the present invention; Figure 4 It is a structural schematic diagram of a magnetic preload assembly according to an embodiment of the present invention; Figure 5 is a structural schematic diagram of a piezoelectric module according to an embodiment of the present invention; Figure Number: Stand 100; mounting beam 110; flexible connector 111; second mounting slot 112; Moving part 200; ferromagnetic metal strip 210; connecting groove 211; first contact piece 220; Magnetic preload assembly 300; magnetic module 310; piezoelectric module 320; piezoelectric foot 321; tangential piezoelectric stack 3211; vertical piezoelectric stack 3212; connecting ceramic 3213; floor ceramic 3214; second contact piece 3215; back iron plate 330; first mounting slot 331; Guide rail and slider structure 400 ; guide rail groove 410 ; slider body 420 . DETAILED DESCRIPTION

[0025] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0026] In the description of the present invention, it should be understood that descriptions involving orientation, such as orientation or positional relationship indicated as up, down, etc., are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0027] In the description of the present invention, "a plurality" means more than two. If there is a description of "first" or "second", it is only used for the purpose of distinguishing technical features, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features or implicitly indicating the order of the indicated technical features.

[0028] In the description of the present invention, unless otherwise clearly defined, terms such as setting, installing, connecting, etc. should be understood in a broad sense, and technicians in the relevant technical field can reasonably determine the specific meanings of the above terms in the present invention based on the specific content of the technical solution.

[0029] The technical solution of the present invention will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the embodiments described below are only some embodiments of the present invention, not all embodiments.

[0030] Piezoelectric actuators require large preload force clamping to achieve large stroke and high-precision displacement output. In the prior art, a high-rigidity flexible hinge mechanism is used to provide the preload force, but this poses challenges to the structural design, material selection and assembly process. Therefore, an embodiment of the present invention proposes a magnetic preload walking piezoelectric actuator, which uses magnetic force as the preload force to achieve adaptive assembly and ensure the accuracy of displacement output.

[0031] like Figure 1 As shown, the magnetic preload walking piezoelectric actuator according to the embodiment of the present invention comprises: a stand 100, a moving component 200 and a magnetic preload module.

[0032] In order to more clearly describe the positional relationship of each component, the left-right direction is set as the first direction, that is, the X direction indicated in the drawings, the front-back direction is set as the second direction, that is, the Y direction indicated in the drawings, and the up-down direction is set as the third direction, that is, the Z direction indicated in the drawings.

[0033] The moving component 200 is extended along the first direction, is movably disposed on the stand 100 , and is a magnetic component.

[0034] The magnetic preload module includes two magnetic preload components 300, which are respectively arranged on the front and rear sides of the moving part 200. In order to make the force uniform, the two magnetic preload components 300 of the embodiment of the present invention are symmetrically arranged. The magnetic preload components 300 are movably arranged along the second direction relative to the stand 100, and in other directions, the magnetic preload components 300 and the stand 100 are fixedly arranged relative to each other.

[0035] like Figure 1 , 2 As shown in Figure 4, the magnetic preload assembly 300 of the embodiment of the present invention includes at least one magnetic module 310 and at least one piezoelectric module 320, the piezoelectric module 320 includes at least two piezoelectric feet 321, the magnetic module 310 is configured to form a magnetic attraction force along the second direction between the moving part 200 so that the at least two piezoelectric feet 321 are in contact with the moving part 200, and the piezoelectric module 320 is configured to drive the moving part 200 to move along the first direction by alternately driving the piezoelectric feet 321.

[0036] When in use, the magnetic modules 310 on the front and rear sides of the moving component 200 form a magnetic attraction force along the second direction with the moving component 200. The magnetic attraction force serves as a preload force of the piezoelectric module 320, so that the piezoelectric feet 321 on the front and rear sides of the moving component 200 contact with the moving component 200. The moving component 200 is clamped by the piezoelectric modules 320 on the front and rear sides. The piezoelectric module 320 drives the moving component 200 to move along the first direction by alternately driving the piezoelectric feet 321. At this time, the magnetic module 310 does not have direct contact with the moving component 200. The negative stiffness characteristics of the magnetic preload force provided by the magnetic module 310 enable the moving component 200 and the piezoelectric module 320 to achieve adaptive assembly and improve the accuracy of the displacement output.

[0037] Furthermore, the embodiment of the present invention provides a preload force for the walking piezoelectric actuator through a magnetic preload force to achieve a large stroke and high-precision displacement output. The preload force applied by the magnetic module 310 has a negative stiffness characteristic and has working characteristics of large output and no heat generation. It is suitable for working requirements of vacuum, low heat consumption, fast response and large load.

[0038] It is understandable that if Figure 2 As shown, an air gap is formed between the moving component 200 and the magnetic module 310 to generate suction, so that the piezoelectric module 320 and the moving component 200 contact each other and apply a preload force. Under this preload force application mode, the walking piezoelectric actuator has position locking and structural robustness characteristics, and the moving component 200 pushes the moving component 200 to generate displacement output.

[0039] like Figure 1 , 2 As shown in Figures 4 and 5, the magnetic preload component 300 of this embodiment is provided with three magnetic modules 310 and two piezoelectric modules 320, and the three magnetic modules 310 and the two piezoelectric modules 320 are arranged alternately and sequentially along the first direction. In some other embodiments, the magnetic preload component 300 may be provided with other numbers of magnetic modules 310 and piezoelectric modules 320, and in order to ensure the uniformity of contact between the piezoelectric foot 321 and the moving part 200 and to further improve the actuating force, the piezoelectric module 320 is arranged between two adjacent magnetic modules 310 in this embodiment. It can be understood that the magnetic modules 310 are arranged at both the left and right ends of the piezoelectric module 320, so that preload force is formed at both the left and right ends of the piezoelectric module 320.

[0040] Regarding the connection between the magnetic preload assembly 300 and the stand 100, as shown in FIG. Figure 1 and 2As shown, in the embodiment of the present invention, mounting beams 110 are respectively arranged on the front and rear sides of the moving part 200, and the mounting beams 110 extend along the first direction. Flexible connectors 111 are respectively provided at the left and right ends of the mounting beams 110, and the mounting beams 110 are connected to the stand 100 through the flexible connectors 111 so that the mounting beams 110 can move along the second direction relative to the stand 100, and the two magnetic preload components 300 are respectively installed on the two mounting beams 110. The left and right ends of the mounting beams 110 of the present invention are connected to the stand 100 through the flexible connectors 111, which constrain the movement of the mounting beams 110 in the second direction and restrict movement in other directions. When a magnetic attraction is formed between the magnetic preload component 300 and the moving part 200, the mounting beam 110 approaches the moving part 200 along the second direction.

[0041] In some other embodiments, the magnetic preload assembly 300 may be installed on the stand 100 via a sliding structure, so that the magnetic preload assembly 300 may slide on the stand 100 along the second direction.

[0042] like Figure 1 , 2 As shown in FIG. 4 , the magnetic preload assembly 300 of the embodiment of the present invention further includes a back iron plate 330, the magnetic module 310 and the piezoelectric module 320 are detachably mounted on the inner side of the back iron plate 330, and the back iron plate 330 is detachably mounted on the inner side of the mounting beam 110, as shown in FIG. Figure 2 As shown, a plurality of first mounting slots 331 are provided on the inner side surface of the back iron plate 330, and the magnetic module 310 and the piezoelectric module 320 are detachably installed in the plurality of first mounting slots 331 in a one-to-one correspondence, and a second mounting slot 112 is also provided on the inner side surface of the mounting beam 110, and the back iron plate 330 is detachably installed in the second mounting slot 112.

[0043] When in use, the magnetic module 310 and the piezoelectric module 320 can be removed one by one from the back iron plate 330 for maintenance, and the back iron plate 330 can be removed from the mounting beam 110 to achieve modular assembly, which is convenient for assembly.

[0044] The flexible connector 111 of this embodiment is a flexible sheet structure, and the flexible sheet structure is extended along the first direction and the third direction.

[0045] Furthermore, if Figure 3As shown, a guide rail slider structure 400 is provided between the moving component 200 and the stand 100 of this embodiment. The guide rail slider structure 400 is used to limit the movement of the moving component 200 in a first direction. Specifically, a guide rail groove 410 extending along the first direction is provided on the stand 100, and a plurality of slider bodies 420 are provided at the bottom of the moving component 200. The plurality of slider bodies 420 slide in cooperation with the guide rail groove 410. The movement of the moving component 200 is constrained in the first direction by the guide rail slider structure 400, and a large stroke and high-precision displacement output is generated under the clamping and pushing of the magnetic preload module.

[0046] In this embodiment, the stage 100 is fixed, and the moving component 200 as a moving unit is restricted along the first direction. In some embodiments, the moving component 200 is fixed, and the stage 100 is used as a moving unit to generate movement along the first direction.

[0047] like Figure 4 and 5 As shown, each piezoelectric module 320 of the present embodiment is provided with two piezoelectric feet 321. In other embodiments, each piezoelectric module 320 may be provided with other numbers of piezoelectric feet 321. The piezoelectric feet 321 of the present embodiment include a tangential piezoelectric stack 3211 and a vertical piezoelectric stack 3212. The tangential piezoelectric stack 3211 and the vertical piezoelectric stack 3212 are sequentially connected along the second direction. Specifically, the vertical piezoelectric stack 3212 of the present embodiment is connected to the back iron plate 330, while the tangential piezoelectric stack 3211 is in contact with the moving part 200, wherein the vertical piezoelectric stack 3212 is configured to extend along the second direction when a first preset voltage is applied so that the piezoelectric foot 321 is pressed against the moving part 200, and to retract along the second direction when a second preset voltage is applied so that the piezoelectric foot 321 is separated from the moving part 200. In some embodiments, the first preset voltage and the second preset voltage are opposite voltages.

[0048] The tangential piezoelectric stack 3211 is configured to extend along the first direction when a third preset voltage is applied so that the piezoelectric foot 321 pushes the moving part 200 to move along the first direction, and to retract along the first direction when a fourth preset voltage is applied so that the piezoelectric foot 321 returns to its original position. In some embodiments, the third preset voltage and the fourth preset voltage may also be opposite voltages, or the fourth preset voltage may be zero.

[0049] In the piezoelectric module 320, a first preset voltage is applied to the vertical piezoelectric stack 3212 of one of the piezoelectric feet 321, so that the vertical piezoelectric stack 3212 stretches in the second direction so that the piezoelectric foot 321 is pressed against the moving part 200, and a third preset voltage is applied to the tangential piezoelectric stack 3211 in the piezoelectric foot 321, so that the tangential piezoelectric stack 3211 stretches in the first direction so that the piezoelectric foot 321 pushes the moving part 200 to move in the first direction. A second preset voltage is applied to the vertical piezoelectric stack 3212 of the piezoelectric foot 321, so that the vertical piezoelectric stack 3212 retracts along the second direction to separate the piezoelectric foot 321 from the moving part 200, and a fourth preset voltage is applied to the tangential piezoelectric stack 3211 in the piezoelectric foot 321 so that it retracts along the first direction to restore the piezoelectric foot 321 to its original position, and then the voltages of the two piezoelectric feet 321 are alternately controlled to achieve alternating contact and displacement output between the two piezoelectric feet 321 and the moving part 200.

[0050] It can be understood that, when the vertical piezoelectric stack 3212 of the piezoelectric foot 321 in the same piezoelectric module 320 is passed with opposite voltage control signals, it can be achieved that one piezoelectric foot 321 is in contact with the moving part 200 while the other piezoelectric foot 321 is separated, and the alternating voltage control signal will realize the alternating contact and displacement output of the two piezoelectric feet 321 and the moving part 200; the tangential piezoelectric stack 3211 of the piezoelectric foot 321 in contact with the moving part 200 drives the moving part 200 to produce a high-precision displacement output, and the tangential piezoelectric stack 3211 of the piezoelectric foot 321 separated from the moving part 200 adjusts its position to prepare for the next contact, so that the alternating movement of the piezoelectric foot 321 will drive the generation of continuous high-precision displacement output.

[0051] like Figure 5 As shown, a connecting ceramic 3213 is provided between the tangential piezoelectric stack 3211 and the vertical piezoelectric stack 3212 , and a floor ceramic 3214 is provided at one end of the vertical piezoelectric stack 3212 away from the tangential piezoelectric stack 3211 , and the floor ceramic 3214 is connected to the back iron plate 330 .

[0052] Furthermore, the moving component 200 of the embodiment of the present invention is a ferromagnetic metal strip 210, which extends along the first direction. The ferromagnetic metal strip 210 forms a magnetic attraction force with the magnetic module 310. On the one hand, the magnitude of the magnetic attraction force and the magnitude of the preload force can be increased. On the other hand, in the process of the ferromagnetic metal strip 210 moving along the first direction, the magnetic attraction force is maintained between the magnetic module 310 and the ferromagnetic metal strip 210, thereby generating a large stroke, continuous high-precision displacement output.

[0053] In some embodiments, a ferromagnetic metal member may be embedded within the moving part 200 .

[0054] like Figure 1 As shown, the present invention is an embodiment of the ferromagnetic metal strip 210, and the front and rear sides thereof are respectively provided with a first contact piece 220, and the piezoelectric foot 321 is in contact with the first contact piece 220. The provision of the first contact piece 220 can improve the wear resistance of the moving component 200, extend the service life of the moving component 200, and also improve the accuracy of the displacement output. The first contact piece 220 of this embodiment is a ceramic sheet, and the front and rear sides of the ferromagnetic metal strip 210 are respectively provided with connection grooves 211 for installing the first contact piece 220.

[0055] In addition, if Figure 5 As shown, the piezoelectric foot 321 is provided with a second contact piece 3215 in contact with the first contact piece 220. The second contact piece 3215 is also made of a ceramic sheet. The second contact piece 3215 is pasted to the end of the tangential piezoelectric stack 3211. The piezoelectric foot 321 is in contact with the first contact piece 220 through the second contact piece 3215, thereby improving the wear resistance of the piezoelectric foot 321, thereby improving the service life of the piezoelectric foot 321, and also increasing the friction between the piezoelectric foot 321 and the moving part 200, further improving the accuracy of the displacement output, and at the same time achieving the insulation effect.

[0056] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0057] The embodiments of the present invention are described in detail above with reference to the accompanying drawings, but the present invention is not limited to the above embodiments, and various changes can be made within the knowledge scope of ordinary technicians in the relevant technical field without departing from the purpose of the present invention.

Claims

1. A magnetic preloaded walking piezoelectric actuator, characterized in that: include: Stand; A moving part, the moving part extends along a first direction and is movably disposed on the stand, and the moving part is a magnetic component; The magnetic preload module comprises two magnetic preload components respectively arranged on both sides of the moving part, the magnetic preload components are movably arranged relative to the stand along a second direction, the second direction is arranged perpendicular to the first direction, the magnetic preload components include at least one magnetic module and at least one piezoelectric module, the piezoelectric module includes at least two piezoelectric feet, the magnetic module is configured to form a magnetic attraction force along the second direction between the moving part so that at least the two piezoelectric feet are in contact with the moving part, and the piezoelectric module is configured to drive the moving part to move along the first direction by alternately driving at least the two piezoelectric feet.

2. The magnetic preloaded walking piezoelectric actuator according to claim 1, characterized in that: The moving component comprises a ferromagnetic metal strip extending along the first direction. The ferromagnetic metal strip is provided with first contact pieces on two sides facing the two magnetic preload components, respectively. The piezoelectric foot contacts the first contact pieces.

3. The magnetic preloaded walking piezoelectric actuator according to claim 2, characterized in that: The piezoelectric foot is provided with a second contact piece in contact with the first contact piece.

4. The magnetic preloaded walking piezoelectric actuator according to claim 1, characterized in that: The piezoelectric foot comprises a tangential piezoelectric stack and a vertical piezoelectric stack connected in sequence along the second direction, wherein the vertical piezoelectric stack is configured to extend along the second direction under a first preset voltage so that the piezoelectric foot is pressed against the moving component, and to retract along the second direction under a second preset voltage so that the piezoelectric foot is separated from the moving component; The tangential piezoelectric stack is configured to extend along the first direction when a third preset voltage is applied so that the piezoelectric foot pushes the moving part to move along the first direction, and to retract along the first direction when a fourth preset voltage is applied so that the piezoelectric foot returns to its original position.

5. The magnetic preloaded walking piezoelectric actuator according to claim 4, characterized in that: A first connecting insulating sheet is provided between the tangential piezoelectric stack and the vertical piezoelectric stack, a second connecting insulating sheet for installation and fixation is provided at one end of the vertical piezoelectric stack away from the tangential piezoelectric stack, and one end of the tangential piezoelectric stack away from the vertical piezoelectric stack is in contact with the moving component.

6. The magnetic preloaded walking piezoelectric actuator according to claim 1, characterized in that: A plurality of magnetic modules spaced apart along the first direction are respectively disposed on both sides of the moving component, and a piezoelectric module is disposed between two adjacent magnetic modules.

7. The magnetic preloaded walking piezoelectric actuator according to claim 1, characterized in that: The magnetic module includes a plurality of magnets, and the plurality of magnets are periodically arranged in a Halbach array along the first direction and the second direction.

8. The magnetic preloaded walking piezoelectric actuator according to claim 1, characterized in that: Mounting beams extending along the first direction are respectively provided on both sides of the moving component, and flexible connecting pieces are respectively provided at both ends of the mounting beams. The mounting beams are connected to the frame through the flexible connecting pieces so that the mounting beams can move relative to the frame along the second direction, and the two magnetic preload assemblies are respectively installed on the two mounting beams.

9. The magnetic preloaded walking piezoelectric actuator according to claim 8, characterized in that: The magnetic preload assembly comprises a back iron plate, the magnetic module and the piezoelectric module are detachably mounted on the inner side of the back iron plate, and the back iron plate is detachably mounted on the inner side of the mounting beam.

10. The magnetic preloaded walking piezoelectric actuator according to claim 1, characterized in that: A guide rail and slider structure is provided between the moving component and the stand, and the guide rail and slider structure is used to limit the movement of the moving component in the first direction.

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