Piezoelectric actuator

Abstract

The utility model belongs to the technical field of micro-driving equipment, and provides a piezoelectric actuator which comprises a shell structure, a piezoelectric structure, a motion guiding structure and a transmission output structure, the shell structure is internally provided with a containing space with a first opening, and the piezoelectric structure is connected to the bottom of the containing space; the transmission output structure is located at the first opening to output the displacement generated by the piezoelectric structure, and the motion guide structure is located between the transmission output structure and the piezoelectric structure and used for providing motion guide for the piezoelectric structure and separating the piezoelectric structure from the transmission output structure, so that the transmission effect of tangential stress is reduced; and a connecting groove is formed in the motion guide structure, so that the length of a force arm of the piezoelectric structure is reduced, the risk of damage to the piezoelectric structure is further reduced, the deflection angle can be reduced, and the guide effect is improved. Therefore, the piezoelectric actuator has excellent structural stability, working reliability and applicability, and can adapt to various complex application scenes.

Description

Technical Field

[0001] The present application relates to the field of micro-drive technology, and in particular to a piezoelectric actuator. Background Art

[0002] A piezoelectric actuator is a device that uses the inverse piezoelectric effect of piezoelectric materials to achieve precise displacement control. Piezoelectric materials, such as piezoelectric ceramics, have unique physical properties: when voltage is applied to them, the piezoelectric material deforms and produces displacement, and when mechanical stress is applied to them, the piezoelectric material generates an electric charge. Piezoelectric actuators are usually formed by stacking multiple layers of piezoelectric materials to form a piezoelectric stack structure. Electrodes are usually connected to both ends of the piezoelectric stack. When a certain voltage is applied to the piezoelectric stack, according to the inverse piezoelectric effect, the piezoelectric stack will deform along the axial direction of its stack, allowing the entire piezoelectric stack to provide a large displacement output. The displacement generated is precisely controllable, with high accuracy and fast response, making it suitable for a variety of applications requiring high-precision positioning.

[0003] Currently, prestressed piezoelectric actuators on the market consist of a piezoelectric ceramic stack, a base, an output pusher, and a housing. The base and output pusher are connected to opposite axial ends of the piezoelectric ceramic stack, and the housing is fitted around the outer periphery of the piezoelectric ceramic stack, the output pusher, and the base. Due to limitations in assembly precision, piezoelectric actuators are inevitably subject to tangential impact during use, causing the piezoelectric ceramic stack to experience significant tangential stress, which can easily cause the stack to fracture and lead to product damage. Furthermore, longer strokes require a longer piezoelectric ceramic stack, further increasing the risk of stack fracture.

[0004] Based on this, in order to solve the above problems, the present application provides a piezoelectric actuator to reduce the risk of fracture of the piezoelectric ceramic stack. Utility Model Content

[0005] In view of the above-mentioned shortcomings of the prior art, the purpose of this application is to provide a piezoelectric actuator to solve the problem in the prior art that the piezoelectric actuator is easily damaged by tangential impact, and to effectively reduce the risk of damage such as breakage of the piezoelectric actuator.

[0006] To achieve the above-mentioned and other related objectives, the present application provides a piezoelectric actuator, comprising:

[0007] A housing structure having an accommodating space therein, wherein one end of the accommodating space is provided with a first opening;

[0008] a piezoelectric structure located within the accommodating space, the piezoelectric structure connected to a bottom portion of the accommodating space away from the first opening, comprising a plurality of piezoelectric elements stacked sequentially from the bottom portion of the accommodating space toward the first opening; a stacking direction of the plurality of piezoelectric elements being a first direction;

[0009] a motion guide structure, located on a side of the piezoelectric structure close to the first opening, and having a connecting groove formed on the side close to the piezoelectric structure, wherein the piezoelectric structure is connected to the bottom of the connecting groove;

[0010] The transmission output structure is located on a side of the motion guide structure away from the piezoelectric structure and passes through the first opening, and is used for outputting the displacement generated by the piezoelectric structure along the first direction.

[0011] Optionally, there is a first gap between the outer side surface of the motion guide structure and the outer shell structure, the width of the first gap is less than or equal to 20 μm, and a first lubricating layer is provided in the first gap.

[0012] Optionally, the transmission output structure includes a transmission base and a transmission output member, and the transmission output member is connected to a side of the transmission base away from the piezoelectric structure; wherein, when looking down at the piezoelectric actuator along the first direction, the outer contour line of the transmission output member is located within the outer contour line of the transmission base.

[0013] Optionally, the transmission output structure further includes:

[0014] a second lubricating layer, located between the transmission base and the motion guide structure, and covering the bottom surface of the transmission base;

[0015] a third lubricating layer covering at least a portion of the outer side surface of the transmission output member;

[0016] The fourth lubricating layer is located between the transmission base and the housing structure and covers the outer side surface of the transmission base.

[0017] Optionally, the piezoelectric actuator further comprises:

[0018] a protective layer, located between the shell and the piezoelectric structure, comprising an anti-sticking layer, the anti-sticking layer at least covering a portion of a side surface of the piezoelectric structure and spaced apart from the motion guide structure;

[0019] The filling packaging layer is located between the protection layer and the shell structure, and is spaced apart from the piezoelectric structure and the motion guiding structure respectively.

[0020] Optionally, the protective layer further comprises elasticity, is located between the anti-sticking layer and the piezoelectric structure, and is spaced apart from the filling packaging layer and the motion guiding structure respectively, and the elastic packaging layer at least covers part of the side surface of the piezoelectric structure.

[0021] Optionally, the filling encapsulation layer includes a plurality of filling segments, and the plurality of filling segments are sequentially spaced apart along the first direction.

[0022] Optionally, the shell structure includes a packaging shell and a packaging base, the bottom surface of the piezoelectric structure is connected to the packaging base, the first opening is located at one end of the packaging shell, and the end of the packaging shell away from the first opening is connected to the packaging base, so that the packaging shell is arranged on the periphery of the packaging base and the piezoelectric structure, and the packaging shell is spaced apart from the piezoelectric structure.

[0023] Optionally, when looking down at the piezoelectric actuator along the first direction, the packaging shell has a circular ring outline or a rectangular ring outline, and the piezoelectric structure has a circular outline or a rectangular outline.

[0024] Optionally, the piezoelectric actuator further comprises:

[0025] a cover plate, spaced apart along the first direction on a side of the transmission base away from the piezoelectric structure, and fixedly connected to the housing structure, the cover plate having a through hole extending along the first direction, the transmission output member passing through the through hole;

[0026] The elastic member surrounds the outer periphery of the transmission output member and is located between the cover plate and the transmission base.

[0027] As described above, the piezoelectric actuator provided by this application has at least the following beneficial effects:

[0028] The piezoelectric actuator of the present application is provided with a transmission guide structure, which has the function of providing motion guidance for the piezoelectric structure, and separates the piezoelectric structure from the transmission output structure, thereby improving the decoupling effect between the tangential stress and the normal stress transmitted by the transmission output structure to the piezoelectric structure, and reducing the transmission effect of the tangential stress; a connecting groove is provided in the motion guide structure, so that the motion guide structure can have a larger thickness along the first direction, reducing its deflection angle, improving the guiding effect, and reducing the force arm length of the piezoelectric structure, thereby reducing the risk of damage to the piezoelectric structure; it can be seen that the piezoelectric actuator of the present application can effectively reduce or prevent the risk of damage to the piezoelectric structure, and while ensuring the protection effect of the piezoelectric structure, it also plays an excellent guiding role, thereby improving the stability, reliability and applicability of the product, enabling it to adapt to a variety of complex application scenarios, effectively overcoming the various defects in the existing technology and having high industrial application value. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without creative work.

[0030] Figure 1 Shown is a structural schematic diagram of the piezoelectric actuator provided in Example 1 of the present application.

[0031] Figure 2 Shown is a specific structural schematic diagram of the piezoelectric actuator housing structure provided in Example 1 of the present application.

[0032] Figure 3 It shows a schematic structural diagram of a piezoelectric actuator in the prior art.

[0033] Figures 4 to 7 Schematic diagrams of the structures of four different cross sections of the piezoelectric actuator provided in the first embodiment of the present application along a direction perpendicular to the first direction are shown respectively.

[0034] Figure 8 Shown is a schematic structural diagram of a piezoelectric actuator with a first lubricating layer provided in Example 1 of the present application.

[0035] Figure 9 Shown is a schematic structural diagram of a piezoelectric actuator with a second lubricating layer provided in Example 1 of the present application.

[0036] Figure 10 Shown is a schematic structural diagram of the third lubricating layer and the fourth lubricating layer provided in Example 1 of the present application.

[0037] Figure 11 Shown is a structural schematic diagram of the piezoelectric actuator provided in Example 2 of the present application.

[0038] Figure 12 and Figure 13 Shown are schematic structural diagrams of a piezoelectric actuator with two filling segments and three filling segments provided in the second embodiment of the present application.

[0039] Reference numerals:

[0040] 1. Shell structure; 11. Package shell; 12. Package base; 101. Accommodating space; 102. First opening; 2. Piezoelectric structure; 21. Piezoelectric element; 3. Protective layer; 31. Anti-sticking layer; 32. Elastic packaging layer; 4. Filling packaging layer; 41. Filling section; 5. Transmission output structure; 51. Transmission output member; 52. Transmission base; 501. Second lubricating layer; 502. Third lubricating layer; 503. Fourth lubricating layer; 61. Cover plate; 611. Through hole; 62. Elastic member; 7. Motion guide structure; 71. Connecting groove; 72. First lubricating layer; 81. Piezoelectric ceramic stack; 82. Shell base; 83. Output push head; 83. Shell body. DETAILED DESCRIPTION

[0041] To make the technical objectives, technical solutions, and technical effects of this application more clear, the technical solutions of this application will be clearly and completely described below in conjunction with embodiments. Obviously, the described embodiments are only part of the embodiments of this application, not all of them. Generally, the components of the embodiments of this application described and shown in the drawings herein can be arranged and designed in various different configurations.

[0042] Therefore, the following detailed description of the embodiments of the present application is not intended to limit the scope of the claimed application, but rather merely represents selected embodiments of the present application. All other embodiments obtained by persons of ordinary skill in the art based on the embodiments in this application without creative effort are within the scope of protection of this application. In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance.

[0043] In the description of this application, it should be noted that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on this application.

[0044] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installed", "connected" and "connected" should be understood in a broad sense. For example, it can be a fixed connection or a detachable connection. In addition, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "example", "specific example" or "some examples" means that the specific features, structures, materials or characteristics described in combination with the implementation or example are included in at least one implementation or example of this application. In this specification, the schematic representation of the above terms does not necessarily refer to the same implementation or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more implementations or examples in a suitable scheme.

[0045] Example 1

[0046] This embodiment provides a piezoelectric actuator for solving the problem in the prior art that the piezoelectric stack is easily damaged when the piezoelectric actuator is subjected to a tangential impact. Figure 1 The piezoelectric actuator provided in this embodiment includes a housing structure 1 , a piezoelectric structure 2 , a motion guide structure 7 and a transmission output structure 5 .

[0047] Reference Figure 1 and Figure 2 The housing structure 1 includes a housing space 101, with a first opening 102 at one end. The housing space 101 is used to mount and secure the piezoelectric structure 2. The first opening 102 serves as the external mounting and positioning interface and displacement output interface for the piezoelectric actuator. In practical applications, the housing structure 1 is typically a metal workpiece to protect the internal piezoelectric structure 2. Alternatively, the housing structure 1 may be made of stainless steel, copper alloy, titanium alloy, or other acceptable materials.

[0048] The piezoelectric structure 2 is located within the accommodating space 101. The piezoelectric structure 2 is a displacement generating structure of the piezoelectric actuator, having a top surface and a bottom surface arranged opposite to each other, and a side surface connecting the top surface and the bottom surface. The bottom surface of the piezoelectric structure 2 is connected to the bottom of the accommodating space 101 away from the first opening 102. The piezoelectric structure 2 includes a plurality of piezoelectric elements 21, which are stacked in sequence from the bottom of the accommodating space 101 toward the first opening 102. The direction in which the plurality of piezoelectric elements 21 are stacked is referred to as the first direction. In actual applications, when a certain voltage is applied to the piezoelectric structure 2, due to the inverse piezoelectric effect of the piezoelectric structure 2, the piezoelectric structure 2 generates a certain deformation along the first direction, and the deformation is transmitted to the transmission output structure 5 to form a displacement output.

[0049] In an optional embodiment, the piezoelectric element 21 is a piezoelectric ceramic monolith, and multiple piezoelectric ceramic monoliths are stacked in sequence from the bottom of the accommodating space 101 to form a piezoelectric ceramic stack, which effectively increases the length of the piezoelectric structure 2 along the first direction, thereby increasing the displacement output of the piezoelectric actuator.

[0050] The motion guiding structure 7 is located on the side of the piezoelectric structure 2 close to the first opening 102, and is used to transmit the displacement of the piezoelectric structure 2 and provide guidance for the displacement of the piezoelectric structure 2 along the first direction; the motion guiding structure 7 is provided with a connecting groove 71 on its side close to the piezoelectric structure 2, and the piezoelectric structure 2 is connected to the bottom of the connecting groove 71. Optionally, the piezoelectric structure 2 is fixedly connected to the bottom of the connecting groove 71. Further, the piezoelectric structure 2 is fixedly connected to the bottom of the connecting groove 71 by bonding.

[0051] The transmission output structure 5 is located on the side of the motion guide structure 7 away from the piezoelectric structure 2. It passes through the first opening 102 and extends to the outside of the accommodating space 101. The transmission output structure 5 is used to output the displacement generated by the piezoelectric structure 2 along the first direction. Optionally, the transmission output structure 5 is spaced apart from the side wall of the first opening 102.

[0052] In the prior art, referring to Figure 3 The structure of the prestressed piezoelectric actuator consists of a piezoelectric ceramic stack 81, a shell base 82, an output push head 83 and an outer shell 83. Some space is reserved between the piezoelectric ceramic stack 81 and the outer shell 83 to facilitate installation and prevent affecting the actuation effect. When the piezoelectric actuator is subjected to a tangential impact perpendicular to the first direction, the tangential force will be transmitted to the piezoelectric ceramic stack 81. Due to the brittleness of the piezoelectric ceramic stack 81 and the bridge structure connecting its two ends, it is very easy to cause damage such as fracture when subjected to tangential stress. There is a high risk of product damage during product transportation, installation and use. The piezoelectric actuator of this embodiment is provided with a motion guiding structure 7, which can provide a guiding effect for the displacement of the piezoelectric structure 2 along the first direction, and realize the decoupling between the normal stress along the first direction and the tangential stress perpendicular to the first direction transmitted by the transmission output structure 5 to the piezoelectric structure 2, thereby reducing the transmission effect of the tangential stress, and thereby reducing the risk of damage such as fracture of the piezoelectric structure 2. In addition, a connecting groove 71 is provided in the motion guiding structure 7, so that the motion guiding structure 7 can have a larger thickness along the first direction, thereby reducing the deflection angle of the motion guiding structure 7 and improving the guiding effect. In addition, by providing the connecting groove 71, the length of the force arm of the piezoelectric structure 2 when subjected to tangential stress can be reduced, further reducing the risk of damage such as fracture of the piezoelectric structure 2, effectively improving the stability and reliability of the product, so that it can adapt to a variety of complex application scenarios.

[0053] In an alternative embodiment, reference Figure 8The motion guiding structure 7 has an outer side surface parallel to the first direction, and a first gap is provided between the outer side surface of the motion guiding structure 7 and the outer shell structure 1. Optionally, the width of the first gap is less than or equal to 20 μm. A first lubricating layer 72 is provided in the first gap to reduce the resistance of the motion guiding structure 7 along the first direction, improve its guiding effect, and thereby reduce the resistance of the piezoelectric actuator during operation. Optionally, the first lubricating layer 72 can be, for example, a Teflon coating or other acceptable material coating.

[0054] In an alternative embodiment, reference Figure 1 and Figure 2 The transmission output structure 5 includes a transmission base 52 and a transmission output member 51. The transmission base 52 is located between the transmission output member 51 and the piezoelectric structure 2, and the transmission output member 51 is connected to the surface of the transmission base 52 on the side away from the piezoelectric structure 2. Optionally, when viewing the piezoelectric actuator from the first direction, the outer contour of the transmission output member 51 is located within the outer contour of the transmission base 52. The transmission output member 51 extends from the accommodation space 101 through the first opening 102 and to the outside of the accommodation space 101. The transmission output structure 5 can be an integrated structure or a discrete structure. Optionally, the transmission output structure 5 adopts an integrated structure, and the transmission base 52 abuts against the motion guide structure 7.

[0055] Further, refer to Figure 9 The transmission base 52 has a top surface, a bottom surface, and an outer side surface connecting the top and bottom surfaces. The transmission output member 51 is connected to the top surface of the transmission base 52. The transmission output structure 5 also includes a second lubricating layer 501. The second lubricating layer 501 is disposed between the transmission base 52 and the motion guide structure 7 and covers the bottom surface of the transmission base 52. Optionally, the second lubricating layer 501 may be a Teflon coating or other acceptable coating. The second lubricating layer 501 further reduces the decoupling effect between the normal stress and the tangential stress transmitted from the transmission output structure 5 to the piezoelectric structure 2, thereby further reducing the transmission of the tangential stress and the risk of damage to the piezoelectric structure 2.

[0056] Further, refer to Figure 10The transmission output structure 5 further includes a third lubricating layer 502 and a fourth lubricating layer 503. The third lubricating layer 502 covers at least a portion of the outer surface of the transmission output member 51. A second gap is defined between the outer surface of the transmission base 52 and the housing structure 1. The fourth lubricating layer 503 is located within the second gap and covers the outer surface of the transmission base 52. Optionally, the third lubricating layer 502 and the fourth lubricating layer 503 can be coatings made of the same or different materials. For example, both the third lubricating layer 502 and the fourth lubricating layer 503 can be Teflon coatings. Alternatively, the third lubricating layer 502 and the fourth lubricating layer 503 can be other acceptable coatings. The third lubricating layer 502 and the fourth lubricating layer 503 can reduce the resistance of the transmission output structure 5 when moving in the first direction, thereby reducing the resistance of the piezoelectric actuator when operating.

[0057] In an alternative embodiment, reference Figure 1 and Figure 2 The shell structure 1 can be an integrated structure or a discrete structure. For example, the shell structure 1 adopts a discrete structure, which can facilitate the installation and fixation of the piezoelectric structure 2; the shell structure 1 includes a packaging base 12 and a packaging shell 11, and the first gap is located between the packaging shell 11 and the outer side surface of the motion guide structure 7. The packaging shell 11 is sleeved on the outer periphery of the packaging base 12 and the piezoelectric structure 2, and is spaced apart from the piezoelectric structure 2; the packaging base 12 has a top surface and a bottom surface and an outer side surface connecting the top surface and the bottom surface, and the piezoelectric structure 2 is fixedly connected to the top surface of the packaging base 12; optionally, the packaging shell 11 is a cylindrical structure, one end of which is connected to the outer side surface of the packaging base 12, so that a receiving space 101 is enclosed between the packaging shell 11 and the packaging base 12.

[0058] Furthermore, the package housing 11 may be adhered to the package base 12 , or fixedly connected to the package base 12 by screws, or fixedly connected to the package base 12 by welding, or may be fixedly connected to the package base 12 by other acceptable methods.

[0059] In this embodiment, refer to Figures 4 to 7 Looking down at the piezoelectric actuator along the first direction, the packaging shell has a circular ring profile or a rectangular ring profile, and the piezoelectric structure 2 has a circular profile or a rectangular profile, that is, the cross-section of the packaging shell along the first direction perpendicular to the first direction is a circular ring structure or a rectangular ring structure, and the cross-section of the piezoelectric structure 2 along the first direction perpendicular to the first direction is a circular structure or a rectangular structure.

[0060] In an alternative embodiment, reference Figure 4 Looking down at the piezoelectric actuator along the first direction, the packaging shell has a circular ring profile, and the piezoelectric structure 2 has a rectangular profile, that is, the cross-section of the packaging shell along the first direction perpendicular to the first direction is a circular ring structure, and the cross-section of the piezoelectric structure 2 along the first direction perpendicular to the first direction is a rectangular structure.

[0061] In an alternative embodiment, reference Figure 5 Looking down at the piezoelectric actuator along the first direction, the packaging shell has a rectangular ring profile, and the piezoelectric structure 2 has a circular profile, that is, the cross-section of the packaging shell along the first direction perpendicular to the first direction is a rectangular ring structure, and the cross-section of the piezoelectric structure 2 along the first direction perpendicular to the first direction is a circular structure.

[0062] In an alternative embodiment, reference Figure 6 Looking down at the piezoelectric actuator along the first direction, the packaging shell has a rectangular ring profile, and the piezoelectric structure 2 has a rectangular profile, that is, the cross section of the packaging shell along the first direction perpendicular to the first direction is a rectangular ring structure, and the cross section of the piezoelectric structure 2 along the first direction perpendicular to the first direction is a rectangular structure.

[0063] In an alternative embodiment, reference Figure 7 Looking down at the piezoelectric actuator along the first direction, the packaging shell has a circular ring profile, and the piezoelectric structure 2 has a circular profile, that is, the cross-section of the packaging shell along the first direction perpendicular to the first direction is a circular ring structure, and the cross-section of the piezoelectric structure 2 along the first direction perpendicular to the first direction is a circular structure.

[0064] It should be noted that users can make the above combinations based on factors such as application scenarios, costs, and processes. There is no absolute optimal choice.

[0065] In an alternative embodiment, reference Figure 1 , the piezoelectric actuator also includes a cover plate 61 and an elastic member 62; the cover plate 61 is arranged on the side of the transmission base 52 away from the piezoelectric structure 2 along the first direction, and is fixedly connected to the shell structure 1; the cover plate 61 and the shell structure 1 form an accommodating space 101, and are spaced apart from the transmission base 52, thereby forming a movement space for the transmission base 52; a through hole 611 is provided in the cover plate 61 that passes through the through hole 611 along the first direction, and the transmission output member 51 passes through the through hole 611 from the accommodating space 101 and extends to the outside of the accommodating space 101. Optionally, there is a third gap between the outer side surface of the transmission output member 51 and the inner wall of the through hole 611, and the third elastic member 62 is provided. The sliding layer 502 at least covers the area of ​​the outer side surface of the transmission output member 51 located in the third gap; the elastic member 62 surrounds the outer periphery of the transmission output member 51 and is located between the cover plate 61 and the transmission base 52. The elastic member 62 can apply prestress to the transmission base 52, so that there is prestress between the transmission output structure 5 and the motion guide structure 7, thereby applying prestress to the piezoelectric structure 2, and at the same time ensuring that the transmission output structure 5 can move along the first direction to output the displacement of the piezoelectric structure 2, thereby improving the structural stability and working reliability of the piezoelectric actuator. Optionally, the elastic member 62 can be, for example, an elastic gasket, a spring or other acceptable elastic structure.

[0066] In summary, the piezoelectric actuator provided in this embodiment is provided with a transmission guide structure, which has the function of providing motion guidance for the piezoelectric structure 2, and separates the piezoelectric structure 2 from the transmission output structure 5, thereby improving the decoupling effect between the tangential stress and the normal stress transmitted by the transmission output structure 5 to the piezoelectric structure 2, and reducing the transmission effect of the tangential stress; a connecting groove 71 is provided in the motion guide structure 7, which reduces the force arm length of the piezoelectric structure 2 and reduces the risk of fracture damage to the piezoelectric structure 2, so that the motion guide structure 7 can have a larger thickness along the first direction, reduce its deflection angle, and improve the guiding effect; a first lubricating layer 72 is provided between the outer shell structure 1, which further improves the guiding effect; a second lubricating layer 501 is provided between the transmission base 52, which further reduces the transmission effect of the tangential stress. It can be seen that the piezoelectric actuator of this embodiment can effectively reduce or prevent the risk of damage to the piezoelectric structure 2. At the same time, while ensuring the protection effect of the piezoelectric structure 2, it reduces the resistance of the piezoelectric actuator during operation, improves the stability, reliability and applicability of the product, enables it to adapt to a variety of complex application scenarios, effectively overcomes the various defects in the existing technology and has high industrial application value.

[0067] Example 2

[0068] This embodiment provides another piezoelectric actuator, which also includes the shell structure 1, piezoelectric structure 2, motion guide structure 7 and transmission output structure 5 in Example 1. The similarities with Example 1 are not repeated here. The difference is that the piezoelectric actuator of this embodiment also includes a protective layer 3 and a filling packaging layer 4.

[0069] Reference Figure 11 In this embodiment, the filling and encapsulation layer 4 is disposed between the housing structure 1 and the piezoelectric structure 2. It supports the travel surface of the piezoelectric structure 2, effectively decomposing the impact energy and preventing damage to the piezoelectric structure 2 caused by excessive local stress. The protective layer 3 is disposed between the filling and encapsulation layer 4 and the piezoelectric structure 2, spacing the filling and encapsulation layer 4 from the piezoelectric structure 2. This prevents adhesion between the filling and encapsulation layer 4 and the piezoelectric structure 2, helps reduce the motion resistance of the piezoelectric structure 2, and ensures the displacement output of the piezoelectric actuator.

[0070] In an optional embodiment, the protective layer 3 includes an anti-sticking layer 31, which covers at least a portion of the side surface of the piezoelectric structure 2 to reduce the resistance of the piezoelectric structure 2 during movement. Optionally, the anti-sticking layer 31 is spaced apart from the motion guide structure 7. The anti-sticking layer 31 can cover a portion of the side surface of the piezoelectric structure 2, or cover the entire side surface of the piezoelectric structure 2. For example, the anti-sticking layer 31 covers the side surface of the piezoelectric structure 2 except for the area near the first opening 102 and the bottom of the accommodating space 101.

[0071] Furthermore, the anti-sticking layer 31 may be an oily coating or a nano-coating, which can effectively reduce the resistance of the piezoelectric structure 2 during operation.

[0072] In an optional embodiment, the material of the filling encapsulation layer 4 may be a high-rigidity encapsulation adhesive, a composite material or other suitable materials. Furthermore, the material of the filling encapsulation layer 4 is, for example, an encapsulation epoxy adhesive.

[0073] In an optional embodiment, the protective layer 3 also includes an elastic encapsulation layer 32, which is formed between the anti-sticking layer 31 and the piezoelectric structure 2, and is respectively spaced between the filling encapsulation layer 4 and the motion guide structure 7, for reducing the resistance of the piezoelectric structure 2 during movement. Optionally, the elastic encapsulation layer 32 covers at least part of the side surface of the piezoelectric structure 2, for example, the elastic encapsulation layer 32 can cover part of the side surface of the piezoelectric structure 2, or cover the entire side surface of the piezoelectric structure 2, for example, the elastic encapsulation layer 32 covers the side surface of the piezoelectric structure 2 except for the area near the first opening 102 and the bottom of the accommodating space 101, and the anti-sticking layer 31 completely covers the elastic encapsulation layer 32.

[0074] Furthermore, the elastic packaging layer 32 is made of an elastic material. Optionally, the elastic packaging layer 32 can be, for example, a polyurethane coating, a rubber coating, a graphite coating, or other suitable material coating. In actual applications, the piezoelectric structure 2 may have poor straightness along the first direction, resulting in poor linearity of the movement of the piezoelectric structure 2 after the piezoelectric actuator is potted, leading to movement obstruction. The elastic packaging layer 32 made of an elastic material further reduces the resistance to displacement of the piezoelectric structure 2 along the first direction, ensuring the stable output of the piezoelectric actuator, and acts as a tangential elastic constraint on the piezoelectric structure 2, effectively preventing the piezoelectric structure 2 from breaking or other damage when the piezoelectric actuator is subjected to a tangential impact, further improving the protection of the piezoelectric structure 2, and thereby further improving the structural stability and operational reliability of the piezoelectric actuator.

[0075] In an alternative embodiment, reference Figure 12 and Figure 13The filling and packaging layer 4 includes a plurality of filling segments 41, which are arranged in sequence and at intervals along the first direction. Optionally, the filling and packaging layer 4 includes, for example, two filling segments 41, respectively denoted as a first filling segment and a second filling segment. For example, the first filling segment can surround the end of the piezoelectric structure 2 close to the first opening 102, and the second filling segment is located between the first filling segment and the packaging base 12. Alternatively, the filling and packaging layer 4 includes, for example, three filling segments 41, which are evenly spaced and arranged in sequence along the first direction. By configuring the filling and packaging layer 4 as a plurality of spaced filling segments 41, the contact area between the filling and packaging layer 4 and the protective layer 3 can be reduced while ensuring the protective effect of the filling and packaging layer 4 on the piezoelectric structure 2, further reducing the resistance of the piezoelectric actuator when it moves in the first direction, and ensuring the displacement output of the piezoelectric actuator.

[0076] The piezoelectric actuator of this embodiment also includes the shell structure 1, piezoelectric structure 2, motion guide structure 7 and transmission output structure 5 in the first embodiment, and therefore also has the beneficial effects of the first embodiment; moreover, in this embodiment, the filling packaging layer 4 can support the travel surface of the piezoelectric structure 2, fully decompose the impact energy, and avoid damage to the piezoelectric structure 2 caused by excessive local stress; the anti-sticking layer 31 of the protective layer 3 can avoid adhesion between the filling packaging layer 4 and the piezoelectric structure 2, which helps to reduce the movement resistance of the piezoelectric structure 2 and ensure the displacement output of the piezoelectric actuator; further, the protective layer 3 also includes an elastic packaging layer 32, which can avoid the piezoelectric structure The hard contact between the piezoelectric structure 2 and the filling packaging layer 4 reduces the constraint of the piezoelectric structure 2 in the displacement direction, further ensuring the stable output of the piezoelectric actuator; the filling packaging layer 4 includes a plurality of filling segments 41 spaced apart along the first direction, which reduces the contact area between the filling packaging layer 4 and the protective layer 3, and further reduces the resistance of the piezoelectric structure 2 when moving along the first direction; it can be seen that the piezoelectric actuator of this embodiment further reduces the risk of fracture of the piezoelectric structure 2 while ensuring that the piezoelectric actuator has a small movement resistance when it is in action, improves the protection effect of the piezoelectric structure 2, and further improves the stability, reliability and applicability of the product.

[0077] The above embodiments are merely illustrative of the principles and effects of this application and are not intended to limit this application. Anyone skilled in the art may modify, alter, or combine the above embodiments without departing from the spirit and scope of this application. Therefore, all equivalent modifications or variations accomplished by a person of ordinary skill in the art without departing from the spirit and technical concepts disclosed in this application shall be covered by the claims of this application.

Claims

1. A piezoelectric actuator, characterized in that: include: A housing structure (1) is provided with a receiving space (101) therein, and a first opening (102) is provided at one end of the receiving space (101); A piezoelectric structure (2) is located in the accommodating space (101), the piezoelectric structure (2) is connected to the bottom of the accommodating space (101) away from the first opening (102), and includes a plurality of piezoelectric elements (21), wherein the plurality of piezoelectric elements (21) are stacked and arranged in sequence from the bottom of the accommodating space (101) toward the first opening (102); the stacking direction of the plurality of piezoelectric elements (21) is a first direction; a motion guide structure (7) located on a side of the piezoelectric structure (2) close to the first opening (102), and having a connection groove (71) formed on the side close to the piezoelectric structure (2), wherein the piezoelectric structure (2) is connected to the bottom of the connection groove (71); A transmission output structure (5) is located on a side of the motion guide structure (7) away from the piezoelectric structure (2) and passes through the first opening (102), and is used to output the displacement generated by the piezoelectric structure (2) along the first direction.

2. The piezoelectric actuator according to claim 1, wherein A first gap is provided between the outer side surface of the motion guide structure (7) and the outer shell structure (1), the width of the first gap is less than or equal to 20 μm, and a first lubricating layer (72) is provided in the first gap.

3. The piezoelectric actuator according to claim 1, wherein: The transmission output structure (5) comprises a transmission base (52) and a transmission output member (51), wherein the transmission output member (51) is connected to a side of the transmission base (52) away from the piezoelectric structure (2); wherein, when the piezoelectric actuator is viewed from above along the first direction, the outer contour of the transmission output member (51) is located within the outer contour of the transmission base (52).

4. The piezoelectric actuator according to claim 3, wherein: The transmission output structure (5) further comprises: A second lubricating layer (501) is located between the transmission base (52) and the motion guide structure (7), and covers the bottom surface of the transmission base (52); a third lubricating layer (502), covering at least a portion of the outer side surface of the transmission output member (51); The fourth lubricating layer (503) is located between the transmission base (52) and the housing structure (1), and covers the outer side surface of the transmission base (52).

5. The piezoelectric actuator according to claim 1, wherein The piezoelectric actuator further comprises: a protective layer (3) located between the housing structure (1) and the piezoelectric structure (2), comprising an anti-sticking layer (31), wherein the anti-sticking layer (31) covers at least a portion of a side surface of the piezoelectric structure (2) and is spaced apart from the motion guide structure (7); The filling packaging layer (4) is located between the protective layer (3) and the shell structure (1), and is spaced apart from the piezoelectric structure (2) and the motion guide structure (7).

6. The piezoelectric actuator according to claim 5, wherein: The protective layer (3) further includes an elastic packaging layer (32), which is located between the anti-sticking layer (31) and the piezoelectric structure (2), and is spaced apart from the filling packaging layer (4) and the motion guide structure (7), respectively. The elastic packaging layer (32) covers at least part of the side surface of the piezoelectric structure (2).

7. The piezoelectric actuator according to claim 5 or 6, wherein: The filling encapsulation layer (4) comprises a plurality of filling segments (41), and the plurality of filling segments (41) are sequentially spaced apart along the first direction.

8. The piezoelectric actuator according to claim 1, wherein The shell structure (1) comprises a packaging shell (11) and a packaging base (12); the bottom surface of the piezoelectric structure (2) is connected to the packaging base (12); the first opening (102) is located at one end of the packaging shell (11); the end of the packaging shell (11) away from the first opening (102) is connected to the packaging base (12), so that the packaging shell (11) is sleeved on the outer periphery of the packaging base (12) and the piezoelectric structure (2), and the packaging shell (11) and the piezoelectric structure (2) are spaced apart.

9. The piezoelectric actuator according to claim 8, wherein: Looking down at the piezoelectric actuator along the first direction, the packaging shell (11) has a circular ring profile or a rectangular ring profile, and the piezoelectric structure (2) has a circular profile or a rectangular profile.

10. The piezoelectric actuator according to claim 3, wherein The piezoelectric actuator further comprises: a cover plate (61) spaced apart along the first direction on a side of the transmission base (52) away from the piezoelectric structure (2) and fixedly connected to the housing structure (1); the cover plate (61) having a through hole (611) extending along the first direction, and the transmission output member (51) passing through the through hole (611); The elastic member (62) surrounds the outer periphery of the transmission output member (51) and is located between the cover plate (61) and the transmission base (52).

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