Non-contact micro piezoelectric driver and driving method

Abstract

The application provides a non-contact micro piezoelectric driver and a driving method. The driver comprises a driving component, a transmission component and a base component. A periodic sawtooth wave voltage signal is applied to the piezoelectric stack to generate a stretching and shrinking micro deformation, which is amplified by a displacement amplification element to drive the piston to reciprocate, periodically change the volume of a closed cavity composed of the piston, a compression cylinder base and an upper bearing base, cause the periodic pressure change of the gas in the cavity, drive the transmission component to move by the gas, and realize the non-contact transmission of power.

Description

Technical Field

[0001] This invention belongs to the field of micro-rotary machinery power drive, specifically relating to a non-contact micro piezoelectric actuator and driving method. Background Technology

[0002] With the rapid development of science and technology, industrial products, whether in traditional manufacturing or high-precision extreme working conditions, are constantly evolving towards miniaturization and intelligence. The demand for actuators used in micro-rotating machinery, characterized by lightweighting, integration, and intelligence, is increasing, placing higher demands on actuator performance indicators such as fast response speed, good overload capacity, and long service life. Piezoelectric actuation converts the deformation energy of a piezoelectric element into the kinetic energy of a transmission mechanism to drive the output shaft to rotate. This motion offers advantages such as high displacement resolution, strong resistance to electromagnetic interference, simple structure, and ease of miniaturization and control. This has led to an exceptionally rapid industrialization of micro-actuators using piezoelectric actuation, with applications in micro-robotics, high-precision positioning mechanisms, optical zoom systems, and other fields.

[0003] In existing technologies, piezoelectric stacks produce linear micro-deformation upon application of a voltage signal. Current actuators using a single piezoelectric stack as the energy conversion element are mostly linear actuators. Rotary actuators using a single piezoelectric stack as the power source are generally based on the principle of inertial impact, employing various displacement amplification mechanisms to convert the linear micro-displacement of the piezoelectric stack into the oscillating displacement of the amplification mechanism. This drives a rotor, which is in contact with the amplification mechanism and subjected to a certain preload, to rotate in a stepping motion, thereby rotating the output shaft, which is fixed to the rotor, to output power and achieve the conversion of different energy forms. In rotary actuators using this approach, the contact between the amplification mechanism and the rotor is surface contact with a certain preload. After prolonged operation, the contact surface will experience wear due to friction, gradually reducing the actuator's response speed, rotational accuracy, and even causing slippage between the stator and rotor contact surfaces, leading to stalling and affecting the actuator's service life. Summary of the Invention

[0004] The purpose of this invention is to provide a non-contact miniature piezoelectric actuator and driving method, which solves the loss caused by friction driving between the stator and rotor, innovates the driving method between the stator and rotor, and provides a non-contact miniature piezoelectric actuator and driving method.

[0005] A non-contact miniature piezoelectric actuator, comprising: Drive component 1, used to drive transmission component 2 to rotate, includes: The piezoelectric stack 11 and the displacement amplification element 12 are provided. The piezoelectric stack 11 is used to generate longitudinal displacement, and the displacement amplification element 12 is used to amplify the longitudinal displacement generated by the piezoelectric stack 11. The piezoelectric stack 11 is disposed inside the displacement amplification element 12. The upper end of the displacement amplification element 12 is fixedly disposed by screws. Piston 13 and compressor cylinder seat 14 together with upper bearing seat 22 in transmission component 2 form a closed cavity; The compressed air cylinder seat 14 is fixedly installed by screws and includes a frustum-shaped cylindrical cavity with different cross-sectional areas distributed along the axial direction; the piston 13 is fixed to the lower end of the displacement amplification element 12 by screws and moves along the axial direction with the displacement amplification element 12 to change the volume of the frustum-shaped cylindrical cavity that makes up the sealed cavity; the compressed air cylinder seat 14 is detachably installed on the upper housing 41. The transmission component 2, used to convert the linear motion of the displacement amplification mechanism into the rotational motion of the output shaft, is housed within the lower housing 42, which is detachably connected to the upper housing 41. The upper bearing seat 22 is detachably disposed on the inner wall of the lower housing 42. It also includes: When the air pressure in the sealed cavity of the wind-driven gyroscope rotor 23 increases, the gas is blown from the first frustum hole on the upper bearing seat 22 to the top of the wind-driven gyroscope rotor 23. The top of the rotor is equipped with a rotating shaft, which is matched with an upper one-way bearing. The upper one-way bearing is matched with a bearing seat hole formed by a cylindrical tube on the upper bearing seat 22. The bottom of the rotor is equipped with a threaded hole that is threadedly connected to the output shaft 25. The upper bearing end cover 21 is used to position the outer ring of the upper one-way bearing and is fixed to the upper end face of the cylindrical tube of the upper bearing seat 22 by screws. The output shaft 25 can rotate with the wind-driven gyroscope rotor 23, and it is mounted on the base component 3 via a lower one-way bearing 26. The base component 3 is used to limit the output shaft 25 along the axial direction. It is fixed to the lower end face of the lower housing 42 by screws, and a second frustum hole is opened on it to connect with the first frustum hole.

[0006] Preferably, the displacement amplification element 12 includes: The first flexible hinge 121 is a rhomboid thin plate structure. Supports 1211 are provided at both ends of one diagonal of the rhombus for placing the piezoelectric stack 11. The other two diagonal ends of the rhombus are fixedly connected to the second flexible hinge 122. The second flexible hinge 122 is a lever-type thin plate structure. The upper platform is fixed to the upper cover 5 by bolts, and the lower part is flexibly hinged to the L-shaped plate 1232 of the third flexible hinge 123. The vertical plate 1221 of the second flexible hinge 122 is fixed to the vertical plate 1213 of the first flexible hinge. The third flexible hinge 123 is a lever-type thin plate structure. One end near the second flexible hinge 122 is an inclined plate 1231, which is flexibly hinged to the support 1211 of the first flexible hinge 121. The other end is fixedly connected to the piston 13 with bolts.

[0007] Preferably, the output shaft 25 can rotate with the wind-driven gyroscope rotor 23, and includes: a column 251, a first shoulder 252, a second shoulder 253, a bearing mounting section, a retaining ring groove 254, and an output section; External threads are machined on the column 251, which are matched with the internal threaded hole at the center of the end face of the gyroscope rotor 23 through the elastic washer 24. A bearing retaining ring 27 is placed on the retaining ring groove 254; The lower one-way bearing 26 is installed in the bearing mounting section, and is positioned on both sides by the second shaft shoulder 253 and the bearing retaining ring 27 respectively; the elastic washer 24 is positioned by the first shaft shoulder 252 and the end face of the gyroscope rotor 23.

[0008] A non-contact micro piezoelectric actuation method includes the following steps: When a rising edge sawtooth wave voltage signal is applied: the piezoelectric stack 11 elongates axially, producing a slight deformation. This deformation is amplified by the displacement amplification element 12, which is in interference fit with it, and then pushes the piston 13 to move downward along the axial direction of the inner cavity of the compression cylinder seat 14. The volume of the sealed cavity formed by the piston 13, the compression cylinder seat 14, and the upper bearing seat 22 decreases, the gas in the cavity is compressed, and the gas pressure increases. After the compressed gas passes through the first frustum hole on the upper bearing seat 22, it is blown toward the top of the gyroscope rotor 23 in the transmission component 2. The compressed airflow drives the gyroscope rotor 23 to rotate, and the gyroscope rotor 23 drives the output shaft 25, which is fixed to it, to rotate, thus outputting power. The compressed airflow blows towards the top of the gyroscope rotor 23 and then flows along the spiral cavity between the rotor 23 blades to the root of the blades. It then exits the driver through the second frustum hole at the center of the lower base 31 end face, reducing the accumulation of compressed gas in the lower cylindrical housing 42 and hindering the movement of the rotor 23. When the electrical signal changes to a falling edge sawtooth wave signal: the piezoelectric stack 11 contracts longitudinally and returns to its initial state, the displacement amplification element 12 with interference fit resets, and pulls the piston 13 to move upward along the axial direction of the inner cavity of the compressed air cylinder seat. The volume of the sealed cavity formed by the piston 13, the compressed air cylinder seat 14 and the upper bearing seat 22 increases, and a partial vacuum is formed inside the cavity. Under the action of atmospheric pressure, the gas outside the cavity enters the sealed cavity through the second frustum hole provided at the center of the end face of the lower base 31 and the first frustum hole on the upper bearing seat 22, preparing for the next working process.

[0009] Compared with the prior art, the advantages of the present invention are: 1. This actuator mainly consists of four parts: a drive component, a transmission component, a base component, and a top cover. It utilizes the micro-deformation generated by applying a periodic sawtooth wave voltage signal to the piezoelectric stack. This deformation is amplified by a displacement amplification element and drives the piston to reciprocate. This periodically changes the volume of the sealed cavity formed by the piston, the compressed air cylinder seat, and the upper bearing seat, causing periodic pressure changes in the gas within the cavity. This gas drives the transmission component, achieving non-contact power transmission. This actuator features a simple structure, small size, light weight, easy miniaturization and control, fast response, and long lifespan.

[0010] 2. The displacement amplification element in the drive component is a flexible hinge structure with multi-stage amplification and symmetrical arrangement. A piezoelectric stack is placed between the two supports. When a sawtooth wave voltage signal is applied to the piezoelectric stack, it extends axially, increasing the distance between the two supports. The distance between the two diagonals perpendicular to the supports, i.e., the upper positions of the two second flexible hinges fixed to each other, decreases, causing the two second flexible hinges to move closer together. Since the second flexible hinge is a lever-type thin plate structure, the fixed upper end is the fulcrum, causing the lower ends of the two second flexible hinges to also move closer together. The two Z-shaped lever-type thin plate structures on the left and right are third flexible hinges, flexibly hinged to the lower ends of the second flexible hinges. As the lower ends of the second flexible hinges move closer together, the hinge points of the third flexible hinges also move closer together. At the same time, the first flexible hinge support moves downward, pushing the inclined plates of the left and right third flexible hinges flexibly hinged to the lower support to move along their respective length directions, causing the lower ends of the third flexible hinges fixed to the piston to move downward, thereby pushing the piston to move downward along its own axis.

[0011] 3. The transmission component utilizes the change in volume of the sealed cavity formed by the drive component and the transmission component to cause changes in the air pressure inside the cavity, thereby driving its own movement. The drive component and the transmission component achieve power transmission in a non-contact manner, which changes the traditional piezoelectric motor where the drive component and the transmission component rely on contact to achieve the conversion of different motion forms. The non-contact power transmission has low friction loss, low heat generation, good overload capacity, high service life and high efficiency, and is particularly suitable for high-speed, low-load micro drive applications.

[0012] 4. The upper bearing housing has evenly distributed fan-shaped frustum holes at the root of the cylindrical tube, which are biased towards the central axis. This facilitates airflow guidance and increases the airflow velocity towards the top of the pneumatic gyroscope rotor. The lower base end face has fan-shaped holes that are tangent to the slope of the blades at the root of the gyroscope rotor and are evenly distributed along the central axis, which facilitates the discharge of gas that drives the gyroscope rotor to rotate.

[0013] 5. The upper cover is a convex cylindrical structure. The vertical plate and groove on the lower end face of the upper cover facilitate the effective positioning and power transmission of the piezoelectric stack, the upper cover and the upper cylindrical shell, and the displacement amplification element when the piezoelectric stack undergoes periodic expansion and contraction micro-deformation after the periodic sawtooth wave voltage signal is applied to the driver.

[0014] 6. The bearing housing holes in the central cavities of the upper bearing housing and lower base house one-way bearings, constraining part of the output shaft's motion freedom in the axial and radial directions, ensuring effective unidirectional rotation of the output shaft. Each component of the lower base, compressor housing, and upper cover has a boss structure on its end face to ensure accurate positioning between each pair of components after the driver is assembled. Attached Figure Description

[0015] Figure 1(a) shows the outline of a non-contact miniature piezoelectric actuator; Figure 1(b) is a cross-sectional view of a non-contact miniature piezoelectric actuator; Figure 2(a) is an assembly diagram of the drive components; Figure 2(b) is a structural diagram of the displacement amplification element; Figure 2(c) is a diagram of the piston structure; Figure 2(d) shows the structure of the compressed air cylinder base; Figure 3(a) is an assembly diagram of the transmission components; Figure 3(b) is a structural diagram of the upper bearing end cover; Figure 3(c) is a structural diagram of the upper bearing housing; Figure 3(d) shows the rotor structure of the wind-driven gyroscope; Figure 3(e) is a structural diagram of the output shaft; Figure 4(a) is an assembly diagram of the base components; Figure 4(b) shows the structure of the lower base; Figure 4(c) is a structural diagram of the lower bearing end cover; Figure 5 This is a structural diagram of a cylindrical shell. Figure 6 This is a diagram of the upper cover structure; Figure 7 Schematic diagram of the periodic sawtooth wave voltage signal applied to the driver; Figure 8 This is a structural diagram of the first flexible hinge in the displacement amplification element; Figure 9 This is a structural diagram of the second flexible hinge in the displacement amplification element; Figure 10 This is a structural diagram of the third flexible hinge in the displacement amplification element.

[0016] Among them, 1. driving component; 11. piezoelectric stack; 12. displacement amplification element; 121. First flexible hinge; 1211. Support; 1212. Inclined plate; 1213. Vertical plate; 122. Second flexible hinge; 1221. Vertical plate one; 1222. Base; 123. Third flexible hinge; 1231. Inclined plate one; 1232. L-shaped plate; 13. Piston; 14. Compressor cylinder seat; 2. Transmission components; 21. Upper bearing end cover; 22. Upper bearing seat; 23. Pneumatic gyroscope rotor; 24. Elastic washer; 25. Output shaft; 251. Threaded cylinder; 252. Shoulder 1; 253. Shoulder 2; 254. Retaining ring groove; 26. Lower one-way bearing; 27. Bearing retaining ring; 3. Base components; 31. Lower base; 32. Lower bearing end cover; 33. Screw; 4. Cylindrical housing; 41. Upper cylindrical housing; 42. Lower cylindrical housing; 5. Top cover; 51. Vertical plate; 52. Screw hole; 53. Mounting groove; 54. Screw hole; 55. Wire hole. Implementation

[0017] The non-contact micro piezoelectric actuator and driving method of the present invention will now be described in more detail with reference to the schematic diagrams, which illustrate preferred embodiments of the invention. It should be understood that those skilled in the art can modify the invention described herein while still achieving its advantageous effects. Therefore, the following description should be understood as being of general knowledge to those skilled in the art and is not intended to limit the invention.

[0018] As shown in Figures 1(a) to 10, the non-contact micro piezoelectric actuator consists of a drive component 1, a transmission component 2, a base component 3, a cylindrical shell 4, and a top cover 5.

[0019] Piston 13, compressor seat 14, and upper bearing seat 22 form a sealed cavity. Drive component 1 compresses the volume of the sealed cavity, increasing the internal gas pressure. This gas drives transmission component 2 to move, which in turn rotates output shaft 25, outputting power. This achieves the conversion of different energy forms.

[0020] The drive unit 1 mainly comprises four parts: a piezoelectric stack 11, a displacement amplification element 12, a piston 13, and a compressed air cylinder seat 14. The piezoelectric stack 11 is placed longitudinally between the two supports of the displacement amplification element 12 and is interference-fitted with the supports. The longitudinal expansion and contraction micro-deformation generated by the piezoelectric stack 11 after a voltage signal is applied is transmitted to the displacement amplification element 12.

[0021] The displacement amplification element 12 is a multi-stage amplification symmetrical flexible hinge structure. This structure consists of a first flexible hinge 121, a second flexible hinge 122, and a third flexible hinge 123.

[0022] In this embodiment, the "flexible hinge" can be a thin plate or other flexible component.

[0023] The first flexible hinge 121 is a rhomboid thin plate structure. Supports 1211 are set at both ends of one diagonal of the rhombus for placing the piezoelectric stack 11. The two ends of the other diagonal of the rhombus are fixedly connected to the second flexible hinge 122. Specifically, it consists of 4 inclined plates 1212 + 2 supports 1211 + 2 vertical plates 1213, forming a symmetrical rhomboid thin plate structure.

[0024] The purpose of aligning the diagonal as the central axis is to ensure that the rhombic thin-plate structure can be decomposed into two symmetrical triangular amplification mechanisms. The second and third flexible hinges are also designed as symmetrical structures. This way, when the piezoelectric stack undergoes longitudinal expansion and contraction deformation, the amplification mechanism amplifies the deformation, enabling the piston to reciprocate axially along its own axis. The rhombic structure can be decomposed into two symmetrical triangular amplification mechanisms. The magnification factor of each triangular amplification mechanism depends only on the angle between the hypotenuse of the triangle and the horizontal direction; the smaller the angle, the greater the magnification.

[0025] The second flexible hinge 122 is a lever-type thin plate structure. The upper platform is fixed to the upper cover 5 by bolts, and the lower part is flexibly hinged to the third flexible hinge 123.

[0026] The second flexible hinge 122 (two symmetrically arranged) consists of a base 1222 and a vertical plate 1221 (the base 1222 is flexibly hinged to the upper end of the vertical plate 1221). The vertical plate 1221 is fixedly connected to the vertical plate 1213 of the first flexible hinge. As can be seen from the diagram of the first flexible hinge, the vertical plate is thicker than the inclined plate. Because the base 1222 is fixed to the upper cover, the vertical plate 1221 of the second flexible hinge 122 is subjected to the tension of the vertical plate 1213 of the first flexible hinge, and they move closer together with the flexible hinge point at the base 1222 as the fulcrum.

[0027] The third flexible hinge 123 is a thin plate structure similar to a Z-shaped lever.

[0028] One end near the second flexible hinge 122 is an inclined plate 1231, which is flexibly hinged to the support 1211 of the first flexible hinge 121. The other end is fixed to the piston 13 with bolts to amplify the micro-deformation generated by the piezoelectric stack 11.

[0029] Specifically, the third flexible hinge 123 (two symmetrically arranged) consists of one inclined plate 1231 and one L-shaped plate 1232. One end of the L-shaped plate 1232 is flexibly hinged to the lower end of the vertical plate 1221 of the second flexible hinge, and the other end is fixed to the piston 13 with screws. One end of the inclined plate 1231 is flexibly hinged to the support 1211 in the first flexible hinge 121, and the other end is flexibly hinged to the L-shaped plate 1232 at the hinge point near the lower end of the vertical plate 1221 of the second flexible hinge 122.

[0030] The piston 13 has a cylindrical handle fixedly connected to the displacement amplification element 12 at the center of its upper end face. The handle has a pair of parallel cross-sections perpendicular to each other along the axis of the cylinder. The lower end of the cross-sections has a boss to facilitate the positioning and fixing of the lower end of the displacement amplification element 12 (the lower end of the L-shaped plate 1232 on the third flexible hinge 123). The lower end face has a frustum-shaped blind hole, which together with the compressed air cylinder seat 14 and the upper bearing seat 22 in the transmission component 2 form a sealed cavity.

[0031] The compressor housing 14 is a cylindrical structure with multiple bosses. The compressor housing and piston 13 are machined together to ensure the airtightness of the cavity when the piston moves axially.

[0032] The upper end face of the compressor holder 14 is provided with a boss for positioning the upper cylindrical shell 41, and the lower end face is provided with a boss for positioning the lower cylindrical shell 42. The center of the end face of the compressor holder 14 is a composite cavity structure composed of a cylindrical cylinder and a frustum cylinder (the boss on the upper end face of the compressor holder 14 surrounds the outside of the composite cavity structure). The cylindrical cylinder facilitates the axial movement of the piston 13 (the deformation direction of the piezoelectric stack 11), and the frustum cylinder is used to change the volume of the sealed cavity when the piston 13 moves axially. Screw holes and bolt holes are evenly distributed around the end face of the compressor holder 14 for fixing the upper cylindrical shell 41 and the lower cylindrical shell 42.

[0033] The transmission component 2 mainly consists of four parts: an upper bearing housing 22, an upper bearing end cover 21, a pneumatic gyroscope rotor 23, and an output shaft 25. The upper bearing housing 22 is a disc-shaped structure with a cylindrical tube. The cylindrical tube at the center of the upper bearing housing 22 has a bearing seat hole for placing the upper one-way bearing. On the disc-shaped end face of the upper bearing housing 22 (near the root of the cylindrical tube), there are evenly distributed fan-shaped frustum holes (first frustum holes) offset from the central axis of the upper bearing housing 22. This facilitates the guidance of compressed airflow and increases the airflow velocity blown towards the top of the pneumatic gyroscope rotor 23 in the transmission component 2 through this hole. Screw holes are evenly distributed around the circumference of the disc-shaped end face of the upper bearing housing 22 for fixing it to the lower cylindrical shell 42.

[0034] The upper bearing end cover 21 is a cylindrical structure with a cylindrical boss. The end face of the cylindrical boss positions the outer ring of the one-way bearing. The disc-shaped end face has screw holes evenly distributed in the circumferential direction and is fixed to the upper end face of the cylindrical tube of the upper bearing seat 22 by screws.

[0035] The wind-driven gyroscope rotor 23 is a multi-helical vane conical structure with evenly distributed vanes along the central axis and different helical angles along the axial direction. The top of the gyroscope rotor 23 has a rotating shaft that mates with an upper one-way bearing. The inner ring of the upper one-way bearing does not axially constrain the top rotating shaft of the wind-driven gyroscope rotor 23, facilitating axial self-adjustment of the rotor 23, reducing motion resistance caused by machining and assembly factors of various components, and improving energy conversion efficiency. The bottom end face of the gyroscope rotor 23 has a threaded hole at its center, which is threadedly connected to a section of the output shaft 25 (the threaded cylinder 251).

[0036] The output shaft 25 is a cylindrical structure with double shoulders, including a column 251, shoulder one 252, shoulder two 253, bearing mounting section, retaining ring groove 254 and output section connected in sequence.

[0037] External threads are machined on the column 251, which mate with the internal threaded hole at the center of the end face of the gyroscope rotor 23 via an elastic washer 24 to prevent relative movement between the gyroscope rotor 23 and the output shaft 25 during driver operation. The output shaft 25 is provided with a first shoulder 252, a second shoulder 253, and a retaining ring groove 254. After the bearing retaining ring 27 is placed on the retaining ring groove 254, the elastic washer 24 and the lower one-way bearing 26 are positioned to prevent axial movement along the output shaft 25. Specifically, the lower one-way bearing 26 is installed in the bearing mounting section, positioned on both sides by the second shoulder 253 and the bearing retaining ring 27, respectively; the elastic washer 24 is positioned by the first shoulder 252 and the end face of the gyroscope rotor 23.

[0038] The base component 3 consists of two parts: a lower base 31 and a lower bearing end cover 32. The lower base 31 has an axially oriented boss for positioning the lower cylindrical housing 42 and a bearing seat hole (for engaging with the lower one-way bearing 26). The boss positioning the lower cylindrical housing 42 surrounds the outside of the fan-shaped hole on it. The end face of the lower base 31 has fan-shaped holes (second frustum holes) tangential to the slope of the root blades of the gyroscope rotor 23 and evenly distributed along its center, facilitating the discharge of gas that drives the gyroscope rotor 23 to rotate. The end face also has evenly distributed screw holes for fixing to the lower bearing end cover 32 and the lower cylindrical housing 42. The lower bearing end cover 32 is a hollow cylindrical structure with a boss, fixed to the bearing seat hole of the lower base 31 by screws 33, positioning the lower one-way bearing 26 placed within the bearing seat hole of the lower base 31. This limits the radial movement, axial movement, and reverse rotation of the output shaft 25.

[0039] The cylindrical housing 4 comprises two parts: an upper cylindrical housing 41 and a lower cylindrical housing 42. Both ends of the upper cylindrical housing 41 are provided with evenly distributed screw holes for securing the upper cover 5 and the compressed air cylinder seat 14. The lower cylindrical housing 42 is a cylindrical structure with flanges and multiple internal steps. The inner stepped cylindrical wall is used to position the compressed air cylinder seat 14, the upper bearing seat 22, and the lower base 31. Both ends of the lower cylindrical housing 42 are also provided with evenly distributed screw holes for securing it to the compressed air cylinder seat 14, the upper bearing seat 22, and the lower base 31.

[0040] The upper cover 5 is a cylindrical structure with a boss. The boss is used to position the upper cylindrical housing 41. The center of the upper end face is provided with a wire hole 55 and evenly distributed screw holes to facilitate the introduction of driver signal lines and fixation of the upper cylindrical housing 41. The center of the lower end face is symmetrically provided with a pair of parallel vertical plates 51, mounting grooves 53 and screw holes 54 to limit the lateral (perpendicular to the longitudinal direction) movement of the piezoelectric stack 11. The mounting grooves 53 are used to position the displacement amplification element 12 in the drive component.

[0041] The non-contact miniature piezoelectric actuator driving method is as follows: After assembly, the non-contact miniature piezoelectric actuator, consisting of the piston 13 in drive component 1, the compressed air cylinder seat 14, and the upper bearing seat 22 in transmission component 2, forms a sealed cavity. When the volume of the sealed cavity decreases, the air pressure inside increases. This gas is blown through a fan-shaped frustum-shaped hole on the end face of the upper bearing seat 22, offset from its central axis, towards the top of the pneumatic gyroscope rotor 23, causing the gyroscope rotor 23 to rotate. This, in turn, drives the output shaft 25, which is fixed to it, to rotate, thus outputting power. This achieves the conversion of different energy forms using compressed gas as a medium.

[0042] Specifically, when a rising edge sawtooth wave voltage signal is applied, as shown in the attached diagram... Figure 7 As shown. The piezoelectric stack 11 elongates axially, generating a slight deformation. This deformation is amplified by the displacement amplification element 12, which is in interference fit with it, and then pushes the piston 13 to move downward along the axial (longitudinal) direction of the inner cavity of the compression cylinder seat 14. The volume of the sealed cavity formed by the piston 13, the compression cylinder seat 14, and the upper bearing seat 22 decreases, and the gas inside the cavity is compressed, increasing the gas pressure. This compressed gas passes through the fan-shaped frustum holes evenly distributed at the root of the cylindrical tube of the upper bearing seat 22, which are offset from the central axis, and blows towards the top of the gyroscope rotor 23 in the transmission component 2. The compressed airflow drives the gyroscope rotor 23 to rotate, and the gyroscope rotor 23 drives the output shaft 25, which is fixed to it, to rotate, thus outputting power. After the compressed airflow blows towards the top of the gyroscope rotor 23, it flows along the spiral cavity between the rotor 23 blades to the root of the blades, and then exits the driver through the fan-shaped holes evenly distributed along the center of the end face of the lower base 31, which are tangential to the slope of the root spiral blades. This reduces the accumulation of compressed gas in the lower cylindrical shell 42, which hinders the movement of the rotor 23.

[0043] When the electrical signal changes to a falling-edge sawtooth wave signal, as shown in the attached image... Figure 7 As shown. The piezoelectric stack 11 contracts longitudinally, returning to its initial state. The displacement amplification element 12, which is interference-fitted with it, resets, pulling the piston 13 to move upward along the axial direction of the inner cavity of the compressed air cylinder seat. The volume of the sealed cavity formed by the piston 13, the compressed air cylinder seat 14, and the upper bearing seat 22 increases, and a partial vacuum is formed inside the cavity. Under the action of atmospheric pressure, the gas outside the cavity enters the sealed cavity through the fan-shaped hole tangent to the slope of the root blades of the gyroscope rotor 23 provided at the center of the end face of the lower base 31 and the fan-shaped frustum holes evenly distributed at the root of the cylindrical tube of the upper bearing seat 22, which are biased towards the central axis, in preparation for the next working process.

[0044] When a periodic rising-edge sawtooth wave signal is applied to the driver, the compressed gas drives the gyroscope rotor 23 to rotate, which in turn drives the output shaft 25, which is fixed to it, to rotate, thus outputting torque. When a periodic falling-edge sawtooth wave signal is applied, the piston 13 moves upward and resets. The volume of the sealed cavity formed by the piston 13, the compressed air cylinder seat 14, and the upper bearing seat 22 increases, creating a partial vacuum. Gas from outside the cavity enters the sealed cavity under atmospheric pressure. Due to the high frequency of the applied periodic sawtooth wave signal and the rotational inertia of the gyroscope rotor 23, the output shaft 25 will rotate continuously in one direction, outputting power and driving the load.

[0045] The above are merely preferred embodiments of the present invention and do not constitute any limitation on the present invention. Any equivalent substitutions or modifications made by those skilled in the art to the technical solutions and content disclosed in the present invention without departing from the scope of the present invention shall be deemed to have remained within the protection scope of the present invention.

Claims

1. A non-contact miniature piezoelectric actuator, characterized in that, include: Drive component (1), used to drive transmission component (2) to rotate, includes: A piezoelectric stack (11) and a displacement amplification element (12) are provided. The piezoelectric stack (11) is used to generate longitudinal displacement, and the displacement amplification element (12) is used to amplify the longitudinal displacement generated by the piezoelectric stack (11). The piezoelectric stack (11) is disposed inside the displacement amplification element (12). The upper end of the displacement amplification element (12) is fixed by screws. The piston (13) and the compressor seat (14) together with the upper bearing seat (22) in the transmission component (2) form a closed cavity; The compressed air cylinder seat (14) is fixed by screws and includes a frustum-shaped cylindrical cavity with different cross-sectional areas distributed along the axial direction; the piston (13) is fixed to the lower end of the displacement amplification element (12) by screws and moves along the axial direction with the displacement amplification element (12) to change the volume of the frustum-shaped cylindrical cavity that makes up the sealed cavity; the compressed air cylinder seat (14) is detachably disposed on the upper housing (41). The transmission component (2), used to convert the linear motion of the displacement amplification mechanism into the rotational motion of the output shaft, is placed inside the lower cylindrical housing (42). The lower cylindrical housing (42) is detachably connected to the upper housing (41). The upper bearing seat (22) is detachably disposed on the inner wall of the lower cylindrical housing (42). It also includes: When the air pressure in the sealed cavity of the wind-driven gyroscope rotor (23) increases, the gas is blown from the first frustum hole on the upper bearing seat (22) to the top of the wind-driven gyroscope rotor (23). The top of the rotor is provided with a rotating shaft, which is matched with the upper one-way bearing. The upper one-way bearing is matched with the bearing seat hole formed by the cylindrical tube on the upper bearing seat (22). The bottom of the rotor is provided with a threaded hole that is threadedly connected to the output shaft (25). The upper bearing end cap (21) is used to position the outer ring of the upper one-way bearing and is fixed to the upper end face of the cylindrical tube of the upper bearing seat (22) by screws; The output shaft (25) can rotate with the wind-driven gyroscope rotor (23), and it is mounted on the base component (3) via a lower one-way bearing (26); The base component (3) is used to limit the output shaft (25) along the axial direction. It is fixed to the lower end face of the lower cylindrical housing (42) by screws, and a second frustum hole is opened on it to connect the first frustum hole.

2. The non-contact micro piezoelectric actuator according to claim 1, characterized in that, The displacement amplification element (12) includes: The first flexible hinge (121) is a rhomboid thin plate structure. Supports (1211) are provided at both ends of one diagonal of the rhombus for placing the piezoelectric stack (11). The other two diagonal ends of the rhombus are fixedly connected to the second flexible hinge (122). The second flexible hinge (122) is a lever-type thin plate structure. The upper platform is fixed to the upper cover (5) by bolts, and the lower part is flexibly hinged to the L-shaped plate (1232) of the third flexible hinge (123). The first vertical plate (1221) of the second flexible hinge (122) is fixed to the vertical plate (1213) of the first flexible hinge. The third flexible hinge (123) is a lever-type thin plate structure. One end near the second flexible hinge (122) is an inclined plate (1231), which is flexibly hinged to the support (1211) of the first flexible hinge (121). The other end is fixedly connected to the piston (13) with bolts.

3. The non-contact micro piezoelectric actuator according to claim 1, characterized in that, The output shaft (25) can rotate with the wind-driven gyroscope rotor (23), and includes: a column (251), a first shoulder (252), a second shoulder (253), a bearing mounting section, a retaining ring groove (254), and an output section; External threads are machined on the column (251), and the elastic washer (24) is used to fit the internal thread hole at the center of the end face of the gyroscope rotor 23; A bearing retaining ring (27) is placed on the retaining ring groove (254); The lower one-way bearing (26) is installed in the bearing mounting section, and is positioned on both sides by the second shaft shoulder (253) and the bearing retainer (27) respectively; the elastic washer (24) is positioned by the first shaft shoulder (252) and the end face of the gyroscope rotor (23).

4. A driving method for the non-contact micro piezoelectric actuator as described in claim 1, characterized in that, Includes the following steps: When a rising edge sawtooth wave voltage signal is applied: the piezoelectric stack (11) elongates axially, and the micro deformation is amplified by the displacement amplification element (12) that is interference-fitted with it, and pushes the piston (13) to move downward along the axial direction of the inner cavity of the compression cylinder seat (14); the volume of the sealed cavity formed by the piston (13), the compression cylinder seat (14) and the upper bearing seat (22) shrinks, the gas in the cavity is compressed, the gas pressure increases, and the compressed gas blows to the top of the gyroscope rotor 23 in the transmission component 2 after passing through the first frustum hole on the upper bearing seat (22). The compressed airflow drives the gyroscope rotor (23) to rotate, and the gyroscope rotor (23) drives the output shaft (25) that is fixed to it to rotate, and outputs power; The compressed airflow blows towards the top of the gyroscope rotor (23) and then flows along the spiral cavity between the rotor (23) vanes to the root of the vanes. It then exits the driver through the second frustum hole at the center of the lower base (31) end face, reducing the accumulation of compressed gas in the lower cylindrical housing (42) and hindering the movement of the rotor (23). When the electrical signal changes to a falling edge sawtooth wave signal: the piezoelectric stack (11) shrinks longitudinally and returns to its initial state. The displacement amplification element (12) that is interference-fitted with it resets and pulls the piston (13) to move upward along the axial direction of the inner cavity of the compressed air cylinder seat. The volume of the sealed cavity formed by the piston (13), the compressed air cylinder seat (14) and the upper bearing seat (22) increases, and a partial vacuum is formed inside the cavity. Under the action of atmospheric pressure, the gas outside the cavity enters the sealed cavity through the second frustum hole provided at the center of the end face of the lower base (31) and the first frustum hole on the upper bearing seat (22) to prepare for the next working process.

Images