High-reliability pen-type piezoelectric ceramic stack displacement device

Abstract

The application discloses a high-reliability pen-type piezoelectric ceramic stack displacement device, which comprises an anti-pressure cylinder, upper and lower caps arranged at the upper and lower ends of the anti-pressure cylinder, a through hole arranged on the lower cap, an upper half of a stress adapter column arranged at the lower end inside the anti-pressure cylinder, a lower half of the stress adapter column arranged outside the anti-pressure cylinder after extending out of the through hole on the lower cap, a spring arranged between the bottom of the upper half of the stress adapter column and the inner side cover surface of the lower cap, a piezoelectric ceramic stack arranged inside the anti-pressure cylinder, the upper and lower ends of the piezoelectric ceramic stack being in contact with the lower end surface of the upper cap and the upper end surface of the stress adapter column respectively and ensuring that the upper and lower ends of the piezoelectric ceramic stack are concentric, a sleeve bearing arranged between the outer wall of the upper part of the stress adapter column and the inner wall of the lower part of the anti-pressure cylinder, and a stress block arranged at the bottom of the lower half of the stress adapter column. The piezoelectric ceramic stack has the capacity of bearing torsion and shearing force improved, is not easily damaged, and the use and maintenance costs are reduced.

Description

Technical Field

[0001] This invention relates to displacement devices in the fields of machine vision imaging or electron microscopy scanning, and more specifically to a high-reliability pen-type piezoelectric ceramic stack displacement device. Background Technology

[0002] In the fields of machine vision imaging or electron microscopy, due to the extremely high requirements for the displacement accuracy of electron microscope objectives, pen-type piezoelectric ceramic stack displacement devices are currently commonly used to achieve high-precision displacement of objectives.

[0003] The pen-shaped piezoelectric ceramic stack displacement device not only has the characteristics of strong load capacity, fast displacement frequency, precise stepping and eccentric load bearing, but also has the advantages of small size, simple material selection and convenient installation. It can simultaneously drive multiple objectives to move at the nanometer level with anti-shake precision within the effective distance.

[0004] Even so, existing pen-type piezoelectric ceramic stack displacement devices still suffer from the problem of easy damage to the internal piezoelectric ceramic stack. Due to structural design factors, existing pen-type piezoelectric ceramic stack displacement devices (such as the applicant's previous generation pen-type piezoelectric ceramic stack displacement device, publication number: CN215222042U) are prone to damage to the internal piezoelectric ceramic stack when operating due to the torsional or shear forces, which significantly shortens their service life and increases the cost of use. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a highly reliable pen-shaped piezoelectric ceramic stack displacement device to improve the ability of the piezoelectric ceramic stack to withstand torque and shear force, and to prevent the piezoelectric ceramic stack from being easily damaged.

[0006] To solve the above-mentioned technical problems and achieve the above-mentioned technical effects, the present invention is implemented through the following technical solution:

[0007] A high-reliability pen-shaped piezoelectric ceramic stack displacement device includes a pressure-resistant cylinder, a piezoelectric ceramic stack, an upper cap, a lower cap, a force-bearing block, a force-bearing transition column, a sleeve bearing, and a spring.

[0008] The upper cap and the lower cap are respectively installed on the upper and lower ends of the pressure-resistant cylinder. The lower cap has a through hole on its surface. The upper half of the force-bearing adapter is located at the lower end inside the pressure-resistant cylinder, and the lower half of the force-bearing adapter extends out of the through hole on the lower cap and is located outside the pressure-resistant cylinder. The spring is located between the bottom of the upper half of the force-bearing adapter and the inner surface of the lower cap. The piezoelectric ceramic stack is located entirely inside the pressure-resistant cylinder. The upper and lower ends of the piezoelectric ceramic stack are in contact with the lower end face of the upper cap and the upper end face of the force-bearing adapter, respectively. The upper cap and the force-bearing adapter are respectively centered and limited to ensure that the upper and lower ends of the piezoelectric ceramic stack are concentric, thereby making the piezoelectric ceramic stack less susceptible to shear force and ensuring that the piezoelectric ceramic stack is not easily damaged.

[0009] Meanwhile, the sleeve bearing is located between the outer wall of the upper part of the force-bearing transition column and the inner wall of the lower part of the pressure-resistant cylinder, thereby eliminating the gap between the force-bearing transition column and the pressure-resistant cylinder, which greatly improves the ability of the piezoelectric ceramic stack to withstand torque and shear force; the force-bearing block is located at the bottom of the lower half of the force-bearing transition column, thereby increasing the contact area between the force application point and the working surface, thus improving the service life of the piezoelectric ceramic stack.

[0010] Furthermore, the pressure-resistant cylinder is a straight tube with a hollow interior and open ends, and the piezoelectric ceramic stack is rod-shaped or stick-shaped.

[0011] Furthermore, both the upper and lower ends of the piezoelectric ceramic stack are convex spherical surfaces, the lower end face of the upper cap is a concave conical surface, and the upper end face of the force-bearing adapter post is a concave conical surface. The conical surface of the upper cap and the conical surface of the force-bearing adapter post are concentric. When the piezoelectric ceramic stack is installed inside the pressure-resistant cylinder, the convex spherical surface at the upper end of the piezoelectric ceramic stack contacts the concave conical surface at the lower end of the upper cap, achieving automatic centering and limiting. The convex spherical surface at the lower end of the piezoelectric ceramic stack contacts the conical surface at the upper end of the force-bearing adapter post, also achieving automatic centering and limiting. The piezoelectric ceramic stack is ensured to be concentric at both ends during installation by the upper and lower centering limits of the upper cap and the force-bearing adapter post.

[0012] Furthermore, the piezoelectric ceramic stack comprises an upper piezoelectric ceramic stack, a lower piezoelectric ceramic stack, and a connecting block. The upper end of the upper piezoelectric ceramic stack is a convex spherical surface, and the lower end of the upper piezoelectric ceramic stack is a flat surface. The lower end of the lower piezoelectric ceramic stack is a convex spherical surface, and the upper end of the lower piezoelectric ceramic stack is a flat surface. The lower end of the upper piezoelectric ceramic stack is detachably connected to the upper surface of the connecting block, and the upper end of the lower piezoelectric ceramic stack is detachably connected to the lower surface of the connecting block. The upper and lower piezoelectric ceramic stacks are coaxial. Designing the piezoelectric ceramic stack as a detachable two-section structure allows for replacement of only the damaged section when only one section is damaged, thus facilitating maintenance and replacement and reducing usage and maintenance costs.

[0013] Furthermore, the outer wall of the upper cap is provided with an external thread, and the inner wall of the upper opening of the pressure-resistant cylinder is provided with an internal thread. The upper cap is tightened onto the upper opening of the pressure-resistant cylinder through the cooperation of the internal and external threads. Similarly, the outer wall of the lower cap is provided with an external thread, and the inner wall of the lower opening of the pressure-resistant cylinder is provided with an internal thread. The lower cap is tightened onto the lower opening of the pressure-resistant cylinder through the cooperation of the internal and external threads.

[0014] Furthermore, the force-bearing transition column includes a large column section at the top and a small column section at the bottom. The large column section and the small column section are integrally formed and coaxial. The large column section is located at the bottom end inside the pressure-resistant cylinder. The sleeve bearing is disposed between the outer wall of the large column section and the inner wall of the pressure-resistant cylinder. The small column section extends downward from the through hole on the lower cap and connects to the force-bearing block. The spring is sleeved on the small column section located inside the lower cap, and the upper end of the spring contacts the lower end face of the large column section, while the lower end of the spring contacts the inner bottom surface of the lower cap.

[0015] Furthermore, the circumferential surface of the small column segment located outside the lower cap is provided with external threads, and an internal thread hole is provided on the upper end face of the force-bearing block. The force-bearing block is tightened onto the small column segment of the force-bearing adapter column through the cooperation of the internal and external threads.

[0016] Furthermore, the sleeve bearing is a graphite sleeve bearing.

[0017] Furthermore, the spring is a plurality of disc springs stacked together.

[0018] Furthermore, the spring is four disc springs stacked together.

[0019] The beneficial effects of this invention are as follows:

[0020] This invention designs both ends of the piezoelectric ceramic stack as convex spherical surfaces, and the lower end face of the upper cap and the upper end face of the force-bearing adapter post as concave conical surfaces. This changes the traditional plane-to-plane contact to a spherical-to-conical contact. Therefore, with the conical surface of the upper cap and the conical surface of the force-bearing adapter post concentric, the spherical surface can be stably embedded in the center of the contacting conical surface, thereby achieving automatic centering and limiting. This ensures that the upper and lower ends of the piezoelectric ceramic stack are concentric during installation, making the piezoelectric ceramic stack less susceptible to shear forces and preventing damage.

[0021] This invention designs the piezoelectric ceramic stack as a detachable two-section structure, which allows only the damaged section to be replaced if one section is damaged, thus facilitating repair and replacement and reducing usage and maintenance costs.

[0022] The present invention adds a sleeve bearing between the outer wall of the upper part of the force-bearing adapter column and the inner wall of the lower part of the pressure-resistant cylinder, which eliminates the gap between the force-bearing adapter column and the pressure-resistant cylinder, thereby greatly improving the ability of the piezoelectric ceramic stack to withstand torque and shear force.

[0023] The present invention adds a force-bearing block at the bottom of the lower half of the force-bearing transition column, which increases the contact area between the force application point and the working surface of the pen-shaped piezoelectric ceramic stack displacement device, thereby improving the working life of the piezoelectric ceramic stack.

[0024] As can be seen from the advantages obtained from the above improvements, the present invention significantly improves the ability of the piezoelectric ceramic stack to withstand torsional and shear forces, avoids easy damage to the piezoelectric ceramic stack, greatly improves product reliability, facilitates maintenance and replacement, and reduces the cost of use and maintenance.

[0025] The above description is merely an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention and to implement it according to the contents of the specification, the preferred embodiments of the present invention are described in detail below with reference to the accompanying drawings. Specific embodiments of the present invention are given in detail below with reference to the accompanying drawings. Attached Figure Description

[0026] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this application, illustrate exemplary embodiments of the invention and, together with their description, serve to explain the invention and do not constitute an undue limitation thereof. In the drawings:

[0027] Figure 1 This is a perspective view of the present invention;

[0028] Figure 2 This is a cross-sectional view of the present invention;

[0029] Figure 3 This is an exploded view of the present invention;

[0030] Figure 4 This is a perspective view of the stress-bearing transition column of the present invention;

[0031] Figure 5 This is a cross-sectional view of the lower structure of the present invention;

[0032] Figure 6 This is a cross-sectional view showing the mating relationship between the upper end of the piezoelectric ceramic stack and the upper cap of the present invention;

[0033] Figure 7 This is a cross-sectional view showing the mating relationship between the lower end of the piezoelectric ceramic stack and the force-bearing adapter post of the present invention.

[0034] Figure 8 This is a perspective view of the two-segment piezoelectric ceramic stack of the present invention. Detailed Implementation

[0035] The present invention will now be described in detail with reference to the accompanying drawings and embodiments. The description herein is intended to provide a further understanding of the invention and forms part of this application. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention.

[0036] See Figure 1-3 As shown, a high-reliability pen-shaped piezoelectric ceramic stack displacement device includes a pressure-resistant cylinder 1, a piezoelectric ceramic stack 2, an upper cap 3, a lower cap 4, a force-bearing block 5, a force-bearing adapter column 6, a sleeve bearing 7, and a spring 8.

[0037] The pressure-resistant cylinder 1 is a straight tube with a hollow interior and open ends, and the piezoelectric ceramic stack 2 is rod-shaped or stick-shaped.

[0038] The upper cap 3 and the lower cap 4 are respectively installed on the upper and lower ends of the pressure-resistant cylinder 1. Specifically, the upper cap 3 has an external thread on its outer side wall and an internal thread on the inner side of the upper opening of the pressure-resistant cylinder 1. The upper cap 3 is tightened onto the upper opening of the pressure-resistant cylinder 1 through the cooperation of the internal and external threads. Similarly, the lower cap 4 has an external thread on its outer side wall and an internal thread on the inner side of the lower opening of the pressure-resistant cylinder 1. The lower cap 4 is tightened onto the lower opening of the pressure-resistant cylinder 1 through the cooperation of the internal and external threads.

[0039] The upper half of the force-bearing adapter 6 is located at the lower end inside the pressure-resistant cylinder 1. A through hole is provided on the cover surface of the lower cap 4. The lower half of the force-bearing adapter 6 extends out from the through hole on the lower cap 4 and is located outside the pressure-resistant cylinder 1.

[0040] See Figure 4As shown, the specific structure of the force-bearing transition column 6 may include a large column section 601 located at the upper part and a small column section 602 located at the lower part. The large column section 601 and the small column section 602 are integrally formed and coaxial. The large column section 601 is located at the bottom end inside the pressure-resistant cylinder 1. The sleeve bearing 7 is disposed between the outer wall of the large column section 601 and the inner wall of the pressure-resistant cylinder 1. The small column section 602 extends downward from the through hole on the lower cap 4 and is located outside the pressure-resistant cylinder 1.

[0041] The spring 8 is disposed between the bottom of the upper half of the force-bearing adapter 6 and the inner surface of the lower cap 4, and is used to provide an upward restoring force for the force-bearing adapter 6. See also Figure 5 As shown, the spring 8 can be a plurality of stacked butterfly springs, for example, four butterfly springs stacked together. The four butterfly springs are sleeved on the small column segment 602 located inside the lower cap 4, and the four butterfly springs are pressed between the lower end face of the large column segment 601 and the inner bottom surface of the lower cap 4.

[0042] The piezoelectric ceramic stack 2 is located inside the pressure-resistant cylinder 1. The upper and lower ends of the piezoelectric ceramic stack 2 are in contact with the lower end face of the upper cap 3 and the upper end face of the force-bearing adapter 6, respectively. The upper cap 3 and the force-bearing adapter 6 are respectively center-limited to ensure that the upper and lower ends of the piezoelectric ceramic stack 2 are concentric, thereby making the piezoelectric ceramic stack 2 less susceptible to shear force and ensuring that the piezoelectric ceramic stack 2 is not easily damaged.

[0043] The method to ensure that the upper and lower ends of the piezoelectric ceramic stack 2 are concentric can be as follows: See Figure 6-7 As shown, both the upper and lower ends of the piezoelectric ceramic stack 2 are designed as convex spherical surfaces, the lower end face of the upper cap 3 is designed as a concave conical surface, and the upper end face of the force-bearing adapter 6 is also designed as a concave conical surface. The conical surface of the upper cap 3 and the conical surface of the force-bearing adapter 6 are concentric. When the piezoelectric ceramic stack 2 is installed in the pressure-resistant cylinder 1, the convex spherical surface at the upper end of the piezoelectric ceramic stack 2 contacts the lower end face of the upper cap 3 in a concave conical contact. Since the contact method is changed from the traditional plane-to-plane contact to spherical-to-conical contact, the spherical surface can be stably embedded in the center of the contacting conical surface, thereby achieving automatic centering and limiting, and thus ensuring the concentricity of the upper and lower ends of the piezoelectric ceramic stack 2 during installation.

[0044] See Figure 8As shown, the piezoelectric ceramic stack 2 can be designed as a detachable two-section structure, consisting of an upper piezoelectric ceramic stack 201, a lower piezoelectric ceramic stack 202, and a connecting block 203. The upper end of the upper piezoelectric ceramic stack 201 is a convex spherical surface, and the lower end of the upper piezoelectric ceramic stack 201 is a flat surface. The lower end of the lower piezoelectric ceramic stack 202 is a convex spherical surface, and the upper end of the lower piezoelectric ceramic stack 202 is a flat surface. The lower end of the upper piezoelectric ceramic stack 201 is detachably connected to the upper flat surface of the connecting block 203, and the upper end of the lower piezoelectric ceramic stack 202 is detachably connected to the lower flat surface of the connecting block 203. The upper piezoelectric ceramic stack 201 and the lower piezoelectric ceramic stack 202 are coaxial. This detachable two-section structure allows for replacement of only the damaged section when only one of the two internal piezoelectric ceramic stacks is damaged, thus facilitating maintenance and replacement and reducing usage and maintenance costs.

[0045] The sleeve bearing 7 is disposed between the outer wall of the upper part of the force-bearing transition column 6 and the inner wall of the lower part of the pressure-resistant cylinder 1, thereby eliminating the gap between the force-bearing transition column 6 and the pressure-resistant cylinder 1, thus greatly improving the ability of the piezoelectric ceramic stack 2 to withstand torque and shear force. The sleeve bearing 7 can preferably be a graphite sleeve bearing.

[0046] The force-bearing block 5 is located at the bottom of the lower half of the force-bearing adapter post 6, thereby increasing the contact area between the force application point and the working surface, thus improving the service life of the piezoelectric ceramic stack 2. The connection between the force-bearing block 5 and the force-bearing adapter post 6 can be such that the circumferential surface of the small column segment 602 located outside the lower cap 4 is provided with external threads, and an internal thread hole is opened on the upper end face of the force-bearing block 5. The force-bearing block 5 is tightened onto the small column segment 602 of the force-bearing adapter post 6 through the cooperation of the internal and external threads.

[0047] The working principle of this invention is as follows:

[0048] By applying different voltages to the piezoelectric ceramic stack 2 located inside the pressure-resistant cylinder 1, the length of the piezoelectric ceramic stack 2 is changed. During the length change, the upper end of the piezoelectric ceramic stack 2 remains stationary due to the obstruction of the upper cap 3 at the upper end of the pressure-resistant cylinder 1, while the lower end of the piezoelectric ceramic stack 2 transmits torque to the force-receiving block 5 outside the lower cap 4 through the force-receiving adapter 6. At the same time, the force-receiving adapter 6 exerts a certain amount of compression on the spring 8, and finally the force-receiving block 5 controls the displacement state of this pen-shaped piezoelectric ceramic stack displacement device.

[0049] Since both the upper and lower ends of the piezoelectric ceramic stack 2 are convex spherical surfaces, and the lower end face of the upper cap 3 and the upper end face of the force-bearing adapter 6 are both concave conical surfaces, and given that the conical surfaces of the upper cap 3 and the force-bearing adapter 6 are concentric, the convex spherical surfaces at both ends of the piezoelectric ceramic stack 2 can be stably embedded in the center of the contacting conical surfaces, ensuring the concentricity of the upper and lower ends of the piezoelectric ceramic stack 2 during installation. This makes the piezoelectric ceramic stack 2 less susceptible to shear forces and prevents damage. Because a sleeve bearing 7 is added between the outer wall of the upper part of the force-bearing adapter 6 and the inner wall of the lower part of the pressure-resistant cylinder 1, the gap between the force-bearing adapter 6 and the pressure-resistant cylinder 1 disappears, greatly improving the ability of the piezoelectric ceramic stack 2 to withstand torque and shear forces. Because a force-bearing block 5 is added to the bottom of the lower half of the force-bearing adapter 6, the contact area between the force application point and the working surface of this pen-shaped piezoelectric ceramic stack displacement device increases, thereby improving the service life of the piezoelectric ceramic stack 2.

[0050] When the voltage disappears, the length of the piezoelectric ceramic stack 2 gradually returns to its original state. During the length recovery process, the lower end of the piezoelectric ceramic stack 2 will drive the force block 5 to retract through the force-bearing adapter post 6. At the same time, the previously compressed spring 8 will give the force-bearing adapter post 6 a rebound force, thereby providing an auxiliary rebound force for the reset of the force block 5.

[0051] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A high-reliability piezoelectric ceramic stack displacement device of a pen type, characterized by: The application relates to a piezoelectric ceramic stack device, which comprises a pressure-resistant cylinder (1), a piezoelectric ceramic stack (2), an upper cover cap (3), a lower cover cap (4), a stress block (5), a stress adapter column (6), a sleeve bearing (7) and a spring (8); the pressure-resistant cylinder (1) is a straight pipe with hollow interiors and open ends; the upper cover cap (3) and the lower cover cap (4) are respectively arranged on the upper end and the lower end of the pressure-resistant cylinder (1); a through hole is formed in the cover surface of the lower cover cap (4); the upper half of the stress adapter column (6) is located at the lower end of the pressure-resistant cylinder (1); the lower half of the stress adapter column (6) is located outside the pressure-resistant cylinder (1) after extending out of the through hole in the lower cover cap (4); the sleeve bearing (7) is arranged between the outer wall of the upper part of the stress adapter column (6) and the inner wall of the lower part of the pressure-resistant cylinder (1); the spring (8) is arranged between the bottom of the upper half of the stress adapter column (6) and the inner cover surface of the lower cover cap (4); the stress block (5) is arranged at the bottom of the lower half of the stress adapter column (6); the piezoelectric ceramic stack (2) is in the shape of a rod or a stick; the piezoelectric ceramic stack (2) is located in the pressure-resistant cylinder (1); the upper end and the lower end of the piezoelectric ceramic stack (2) are respectively in contact with the lower end surface of the upper cover cap (3) and the upper end surface of the stress adapter column (6); the upper cover cap (3) and the stress adapter column (6) are respectively limited by centering, so as to ensure the concentricity of the upper end and the lower end of the piezoelectric ceramic stack (2). The upper end and the lower end of the piezoelectric ceramic stack (2) are both in the shape of convex spherical surfaces; the lower end surface of the upper cover cap (3) is in the shape of an inner concave conical surface; the upper end surface of the stress adapter column (6) is in the shape of an inner concave conical surface; the conical surface of the upper cover cap (3) is concentric with the conical surface of the stress adapter column (6); when the piezoelectric ceramic stack (2) is installed in the pressure-resistant cylinder (1), the convex spherical surface of the upper end of the piezoelectric ceramic stack (2) is in contact with the inner concave conical surface of the lower end surface of the upper cover cap (3) and is automatically limited by centering; the convex spherical surface of the lower end of the piezoelectric ceramic stack (2) is in contact with the conical surface of the upper end of the stress adapter column (6) and is automatically limited by centering; the piezoelectric ceramic stack (2) is limited by centering by the upper cover cap (3) and the stress adapter column (6) from top to bottom, so as to ensure the concentricity of the upper end and the lower end of the piezoelectric ceramic stack (2) during installation.

2. The high-reliability piezoelectric ceramic stack displacement device of claim 1, wherein: The piezoelectric ceramic stack (2) is composed of an upper piezoelectric ceramic stack (201), a lower piezoelectric ceramic stack (202) and a connecting block (203); the upper end of the upper piezoelectric ceramic stack (201) is in the shape of a convex spherical surface; the lower end of the upper piezoelectric ceramic stack (201) is in the shape of a plane; the lower end of the lower piezoelectric ceramic stack (202) is in the shape of a convex spherical surface; the upper end of the lower piezoelectric ceramic stack (202) is in the shape of a plane; the lower end of the upper piezoelectric ceramic stack (201) is detachably connected with the upper plane of the connecting block (203); the upper end of the lower piezoelectric ceramic stack (202) is detachably connected with the lower plane of the connecting block (203); and the upper piezoelectric ceramic stack (201) and the lower piezoelectric ceramic stack (202) are coaxial.

3. The high-reliability piezoelectric ceramic stack displacement device of claim 1, wherein: The outer side wall of the upper cap (3) is provided with external threads, the inner wall of the upper end opening of the pressure-resistant cylinder (1) is provided with internal threads, and the upper cap (3) is screwed on the upper end opening of the pressure-resistant cylinder (1) through the cooperation of the internal and external threads; similarly, the outer side wall of the lower cap (4) is provided with external threads, the inner wall of the lower end opening of the pressure-resistant cylinder (1) is provided with internal threads, and the lower cap (4) is screwed on the lower end opening of the pressure-resistant cylinder (1) through the cooperation of the internal and external threads.

4. The high-reliability piezoelectric ceramic stack displacement device of claim 1, wherein: The force receiving adapter column (6) comprises a large column segment (601) at the upper part and a small column segment (602) at the lower part, the large column segment (601) and the small column segment (602) are integrally formed and coaxial, the large column segment (601) is located at the bottom end inside the pressure-resistant cylinder (1), the sleeve bearing (7) is arranged between the outer wall of the large column segment (601) and the inner wall of the pressure-resistant cylinder (1), the small column segment (602) is connected with the force receiving block (5) after extending downward from the through hole on the lower cap (4), the spring (8) is sleeved on the small column segment (602) inside the lower cap (4), and the upper end of the spring (8) is in contact with the lower end surface of the large column segment (601), and the lower end of the spring (8) is in contact with the inner bottom surface of the lower cap (4).

5. The high-reliability piezoelectric ceramic stack displacement device of claim 4, wherein: The circumferential surface of the small column segment (602) outside the lower cap (4) is provided with external threads, an internal screw hole is formed in the upper end surface of the force receiving block (5), and the force receiving block (5) is screwed on the small column segment (602) of the force receiving adapter column (6) through the cooperation of the internal and external threads.

6. The high-reliability piezoelectric ceramic stack displacement device of claim 1 or 4, wherein: The sleeve bearing (7) is a graphite sleeve bearing.

7. The high-reliability piezoelectric ceramic stack displacement device of claim 1 or 4, wherein: The spring (8) is a plurality of stacked disc springs.

8. The high-reliability piezoelectric ceramic stack displacement device of claim 7, wherein: The spring (8) is four stacked disc springs.

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