Piezoelectric rotary driving platform based on stick-slip mechanism and driving method thereof

Abstract

The application discloses a piezoelectric rotary driving platform based on stick-slip mechanism and a driving method thereof. The piezoelectric rotary driving platform comprises a rotary table, a stator, a fixed shaft and a base. The fixed shaft is fixed on the base; the stator is fixed on the outside of the fixed shaft; and the rotary table is coaxially connected with the fixed shaft. The stator is provided with n piezoelectric drivers arranged in sequence along the circumference of the fixed shaft. The piezoelectric driver comprises a piezoelectric ceramic stack, a first compliant structure, a second compliant structure and a driving foot. The first compliant structure utilizes the lever principle to amplify the radial displacement of the driving foot; the second compliant structure adopts an elastically deformable parallelogram structure, which converts the radial movement of the driving foot into tangential movement under the condition that the load capacity of the rotary table is ensured, so as to increase the rotation amplitude of the rotary table.

Description

TECHNICAL FIELD

[0001] The application relates to a piezoelectric rotary driving platform based on a stick-slip mechanism and belongs to the technical field of micro-nano precision driving and positioning. BACKGROUND

[0002] Miniature rotary driving structures generally have motor driving and piezoelectric driving, wherein the structure adopting the piezoelectric driving technology has the advantages of high precision, small size, fast response and anti-electromagnetic interference, and has important application significance in the fields of bioengineering, micro-operation, precision measurement, aerospace and the like.

[0003] The piezoelectric driving is an actuating device for converting electric energy into mechanical energy by using a piezoelectric element. According to the driving principle, the piezoelectric driver mainly has inchworm type, ultrasonic type, stick-slip type and inertia type. The stick-slip type piezoelectric driving structure generally has a stator and a rotor, and the rotor is caused to move by the friction between the stator and the rotor. The piezoelectric driving moves by using the friction force, does not need gear transmission, and can directly drive the rotor; when no power excitation is applied, the original mechanical position can be kept due to the friction between the contact surfaces, energy consumption and heat generation are reduced, and the positioning precision is improved.

[0004] A rotary piezoelectric driving structure based on the stick-slip mechanism is developed. The piezoelectric driver part adopts a lever structure combined with a parallelogram structure for displacement amplification, which significantly increases the single-step step length and the friction driving force of the piezoelectric driving. At present, most piezoelectric driving structures only use one or two piezoelectric stacks to drive the overall mechanism, the driving torque is small, the output performance is low, and the back-off effect is obvious. The application drives the rotary table in the form of three piezoelectric driver arrays in parallel, increases the driving capacity, reduces the back-off effect, and improves the displacement resolution. SUMMARY

[0005] The application aims to solve the problems of ordinary piezoelectric driving structures, such as small output load, low driving speed and poor displacement resolution, and provides a piezoelectric rotary driving platform based on the stick-slip mechanism.

[0006] A piezoelectric rotary driving platform based on the stick-slip mechanism comprises a rotary table, a stator, a fixed shaft and a base. The fixed shaft is fixed on the base; the stator is fixed on the outer side of the fixed shaft; and the rotary table is coaxially rotationally connected with the fixed shaft. The stator is provided with n piezoelectric drivers arranged in sequence along the circumferential direction of the fixed shaft; n>=3.

[0007] The piezoelectric driver comprises a piezoelectric ceramic stack, a first compliant structure, a second compliant structure and a driving foot. The inner end of the first compliant structure is connected with the outer end of the corresponding connecting part through a flexible hinge. The middle part of the inner side surface of the first compliant structure is connected with a push plate through a flexible hinge. The piezoelectric ceramic stack is arranged between the push plate and the corresponding stator.

[0008] The secondary compliant structure is arranged at the outer end of the outer side of the primary compliant structure. The secondary compliant structure comprises two connecting arms and a mounting arm. The inner ends of the two connecting arms, which are parallel and equal in length, are connected with the primary compliant structure. The outer ends of the two connecting arms are connected with the two ends of the mounting arm respectively. The outer side of the mounting arm is fixed with a driving foot. After the piezoelectric ceramic stack is electrified, the driving foot extrudes the turntable to drive the turntable to rotate.

[0009] As preferred, each piezoelectric ceramic stack corresponds to a pre-tightening bolt; the pre-tightening bolt is screwed on the stator and abuts against the inner end of the piezoelectric ceramic stack. The pre-tightening bolt applies pre-tightening force to the piezoelectric ceramic stack.

[0010] As preferred, the outer side of the stator is provided with n driver mounting positions; the driver mounting position comprises a limiting surface and a connecting portion. The inner side of the connecting portion is perpendicular to the limiting surface. The connecting portion is integrally formed with the main body of the stator. The inner end of the primary compliant structure is connected with the outer end of the connecting portion. The n piezoelectric drivers are respectively mounted in the n driver mounting positions; the stator is provided with n second threaded through holes; the n second threaded through holes correspond to the n limiting surfaces respectively. The second threaded through hole penetrates between the inner circumferential surface of the stator and the corresponding limiting surface. The axis of the second threaded through hole is perpendicular to the corresponding limiting surface. The pre-tightening bolt is screwed in the corresponding second threaded through hole.

[0011] As preferred, the outer end of the piezoelectric ceramic stack and the push plate, and the inner end of the piezoelectric ceramic stack and the corresponding pre-tightening bolt are both provided with a gasket.

[0012] As preferred, the outer side of the driving foot is in the shape of a semi-cylinder and is provided with a friction coating.

[0013] As preferred, the inner side of the driving foot is provided with a tenon; the outer side of the mounting arm is provided with a mortise groove; the driving foot is detachably connected through the mortise and tenon structure.

[0014] As preferred, the n piezoelectric drivers on the stator are evenly distributed along the circumference of the fixed shaft.

[0015] As preferred, the turntable comprises a coaxial and integrally formed central shaft, a top turntable and a rotating ring. The rotating ring is sleeved on the outer side of each piezoelectric driver. The central shaft is rotationally connected with the central hole of the fixed shaft.

[0016] As preferred, the central hole of the fixed shaft is embedded with deep groove ball bearings at both ends; the central shaft of the turntable penetrates through the two deep groove ball bearings and is in interference fit with the inner rings of the deep groove ball bearings.

[0017] Preferably, n is 3; the central hole of the stator is arranged outside the fixed shaft; three radial first threaded through holes are arranged on the stator; the three first threaded through holes and the three piezoelectric drivers are alternately arranged along the circumferential direction of the central axis of the stator; and the three distance adjusting bolts are respectively screwed into the first threaded through holes and abut against the fixed shaft. By rotating the three distance adjusting bolts, the eccentricity of the stator and the rotary table and the fixed shaft is adjusted, so that the pressure of the three driving feet on the rotary table is kept suppressed.

[0018] The driving method of the piezoelectric rotary driving platform based on the stick-slip mechanism is as follows:

[0019] Periodic sawtooth-shaped electric signals are applied to the n piezoelectric drivers; along the rotation direction of the rotary table, the sawtooth-shaped electric signals applied to the n piezoelectric drivers are sequentially staggered by 1 / n period; one period of the periodic electric signal includes a rising section and a falling section; the voltage value of the electric signal linearly increases from 0 to the maximum value in the rising section, and linearly decreases from the maximum value to 0 in the falling section. The time length of the rising section is greater than or equal to (n-1) times the time length of the falling section. The piezoelectric drivers all drive the rotary table to rotate in the positive direction in the rising section, and reset in the falling section.

[0020] The present application has the following advantages:

[0021] 1. The primary compliant structure in the present application uses the lever principle to amplify the radial displacement of the driving feet; the secondary compliant structure adopts an elastically deformable parallelogram structure, which converts part of the radial movement of the driving feet into tangential movement to increase the rotation amplitude of the rotary table, while ensuring that the pressure and friction between the driving feet and the inner wall of the rotary table are sufficient and the load capacity of the rotary table is sufficient.

[0022] 2. The present application drives the three piezoelectric drivers arranged around to stagger a certain phase, so that when part of the piezoelectric drivers reset, the remaining piezoelectric drivers continue to drive the rotary table to rotate, thereby effectively suppressing the reset problem of the stick-slip mechanism driver.

[0023] 3. The present application can adjust the degree of deviation between the stator and the rotor axis by adjusting the three distance adjusting bolts, so that the outer edge points of the three driving feet are on the same circle with the rotor axis as the center, and the friction between the three driving feet and the rotary table is kept equal, in the case that the three driving feet have different wear degrees and the machining precision of the stator is insufficient. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 is a schematic view of the appearance of the present application.

[0025] Figure 2 is an exploded view of the present application.

[0026] Figure 3is the structure diagram of the stator and three piezoelectric drivers in the application.

[0027] Figure 4 is the structure diagram of the fixed shaft in the application.

[0028] Figure 5 is the structure diagram of the rotating platform in the application.

[0029] Figure 6 is the working principle diagram of the piezoelectric driver in the application.

[0030] Figure 7 is the diagram of the driving signal of the three piezoelectric ceramic stacks in the application.

[0031] In the figure: 1, piezoelectric ceramic stack; 2, stator; 2.1, first compliant structure; 2.2, second compliant structure; 2.3, driving foot; 2.4, push plate; 3, rotating platform; 3.1, central shaft; 3.2, top rotating disc; 3.3, rotating ring; 4, fixed shaft; 4.1, deep groove ball bearing; 5, distance adjusting bolt; 6, pre-tightening bolt; 7, base DETAILED DESCRIPTION

[0032] The detailed content of the application and its specific implementation will be further illustrated below in combination with the drawings.

[0033] As shown in Figure 1 , 2 and 3, a piezoelectric rotating driving platform based on stick-slip mechanism is provided, which improves the rotating output performance and is of great significance to improve the driving speed and displacement accuracy and suppress the back-off of the rotating platform. The piezoelectric rotating driving platform based on stick-slip mechanism comprises a rotating platform 3, a stator 2 with three piezoelectric driver arrays, a fixed shaft 4 and a base 7. The fixed shaft 4 is fixed on the base 7;

[0034] As shown in Figure 2 , 3 and 4, the stator 2 is coaxially arranged on the outside of the fixed shaft 4 and remains relatively static with the fixed shaft 4 during the working process. Specifically, the central hole of the stator 2 is sleeved on the outside of the fixed shaft 4; three radial first threaded through holes are formed on the stator 2; three blind holes are formed on the fixed shaft 4; the three first threaded through holes and the three blind holes are respectively aligned. Three distance adjusting bolts 5 are respectively threadedly connected in the first threaded through holes, and the end portions abut against the bottoms of the blind holes. The diameter of the blind hole is larger than the diameter of the distance adjusting bolt 5, so that the distance adjusting bolt 5 can move radially in the blind hole. By rotating the three distance adjusting bolts 5, the relative position of the stator 2 to the rotating platform and the fixed shaft can be adjusted, so that the pressure of the three driving feet 2.3 on the inner circumferential surface of the rotating platform remains balanced. After adjusting the position of the stator 2 by the three distance adjusting bolts 5, the stator 2 and the base 7 can be fixed together through the remaining structures (such as the fixing bolts and nuts).

[0035] By adjusting the three distance bolts 5, the size accuracy requirement of the three piezoelectric drivers on the stator 2 can be reduced. Specifically, even if the three driving feet 2.3 fail to be completely on the circular line with the center axis of the stator as the center due to different degrees of wear or machining accuracy problems of the piezoelectric drivers, since three points form a circle, the position of the stator can be adjusted by rotating the three distance bolts 5, so that the three driving feet 2.3 are in contact with the inner circumferential surface of the rotary table, and the pressure is equal.

[0036] As shown in Figure 2 and 5 , the rotary table 3 is coaxially connected with the fixed shaft 4. Specifically, the center hole of the fixed shaft 4 is embedded with deep groove ball bearings 4.1 at both ends; the center shaft of the rotary table 3 passes through the two deep groove ball bearings 4.1 and is in interference fit with the inner ring of the deep groove ball bearings 4.1. The three piezoelectric drivers on the stator 2 are uniformly distributed along the circumference of the fixed shaft 4. The rotary table 3 includes a coaxial and integrally formed center shaft 3.1, a top rotary disc 3.2 and a rotating ring 3.3. The rotating ring is sleeved on the outside of the three piezoelectric drivers.

[0037] As shown in Figure 3 , the outer side of the stator 2 is provided with three driver mounting positions uniformly distributed along the circumference of the fixed shaft 4; the driver mounting position includes a limiting surface and a connecting portion. The inner side surface of the connecting portion is perpendicular to the limiting surface. The connecting portion is integrally formed with the main body of the stator 2. A single piezoelectric driver includes a piezoelectric ceramic stack 1, a first compliant structure 2.1, a second compliant structure 2.2 and a driving foot 2.3. The first compliant structure 2.1 and the second compliant structure 2.2 are both metal elastic bodies integrally formed with the corresponding connecting portion.

[0038] The inner end of the first compliant structure 2.1 is connected to the outer end of the corresponding connecting portion through a flexible hinge. The middle part of the inner side surface of the first compliant structure 2.1 is connected with a push plate 2.4 through a flexible hinge. The piezoelectric ceramic stack 1 is arranged between the push plate 2.4 and the corresponding driver mounting position. When the piezoelectric ceramic stack 1 is energized to elongate, it can push the first compliant structure 2.1 to flip outward. Since the push plate 2.4 can flip relative to the first compliant structure 2.1, the piezoelectric ceramic stack 1 can mainly bear pressure when working, avoiding damage to the stack caused by large transverse force.

[0039] Three second threaded holes are formed in the stator 2; the three second threaded holes correspond to the three limiting surfaces respectively. The second second threaded hole penetrates between the inner circumferential surface of the stator 2 and the corresponding limiting surface. The axis of the second second threaded hole is perpendicular to the corresponding limiting surface. A pre-tightening bolt is screwed in each of the three second threaded holes; the three pre-tightening bolts are aligned with the three push plates 2.4 respectively. The three pre-tightening bolts abut against the inner end of the piezoelectric ceramic stack 1 respectively, and exert a pre-tightening force on the piezoelectric ceramic stack 1. The pre-tightening force is 10% to 20% of the nominal maximum thrust of the piezoelectric ceramic stack 1, to prevent the stack from loosening.

[0040] In this embodiment, a gasket 8 is arranged between the outer end of the piezoelectric ceramic stack 1 and the push plate 2.4, and between the inner end of the piezoelectric ceramic stack 1 and the corresponding pre-tightening bolt; the gasket 8 can play a buffering role and increase the contact area between the piezoelectric ceramic stack and the metal on both sides.

[0041] The secondary compliant structure 2.2 is arranged at the outer end of the outer side surface of the primary compliant structure 2.1. The secondary compliant structure 2.2 is a parallelogram, including two connecting arms and an installation arm; the thickness of the connecting arm is 0.5 mm, and the thickness of the installation arm is 0.6 mm; the material of the primary compliant structure 2.1 and the secondary compliant structure 2.2 is structural steel. The inner ends of the two connecting arms, which are parallel and equal in length, are connected with the primary compliant structure 2.1. The outer ends of the two connecting arms are connected with the two ends of the installation arm respectively. The outer side surface of the installation arm is fixed with a driving foot 2.3; the outer side surface of the driving foot 2.3 is spherical. When the driving foot 2.3 is pressed against the inner circumferential surface of the rotary table 3, the secondary compliant structure 2.2 is elastically deformed, converting the movement of the outer end of the primary compliant structure 2.1 along the radial direction of the fixed shaft into tangential movement, and increasing the rotation amplitude of the rotary table 3. The elastic force generated by the elastic deformation of the secondary compliant structure 2.2 can provide the driving foot 2.3 with a pressing force against the rotor, thereby increasing the rotation amplitude while ensuring that the driving foot 2.3 and the rotor can generate sufficient static friction to drive the load.

[0042] The outer side surface of the driving foot 2.3 is a semicylindrical surface (the axis of the circular arc surface is parallel to the rotary table axis), and is provided with a wear-resistant coating; specifically, a wear-resistant coating based on ceramic particles or metal powder is used; the inner side surface of the driving foot 2.3 is provided with a tenon; the outer side surface of the installation arm is provided with a mortise; the driving foot 2.3 is detachably connected through a mortise-and-tenon structure, so as to facilitate replacement after the driving foot is worn out.

[0043] In this embodiment, the primary compliant structure 2.1 is a lever type displacement amplification structure; the secondary compliant structure 2.2 is a parallelogram displacement amplification structure, and the combination of the two converts the longitudinal displacement (i.e. the displacement along the radial direction of the fixed shaft) of the piezoelectric ceramic stack 1 into coupled displacement in the horizontal and vertical directions.

[0044] The driving method of the piezoelectric rotary driving platform based on stick-slip mechanism is as follows:

[0045] Periodic sawtooth-shaped electric signals are applied to the three piezoelectric drivers; the sawtooth-shaped electric signals applied to the three piezoelectric drivers are sequentially staggered by 120° in phase along the rotation direction of the rotary table; one period of the periodic electric signal includes a rising section and a falling section; the voltage value of the electric signal linearly increases from 0 to the maximum value in the rising section, and linearly decreases from the maximum value to 0 in the falling section. The time length of the rising section accounts for 80% of the period of the sawtooth-shaped electric signal; so that the speed of the driving foot 2.3 pushing the rotary table to rotate is far less than the speed of the driving foot 2.3 resetting, and the amplitude of the reverse rotation of the rotary table when the driving foot 2.3 resets is inhibited.

[0046] As shown in Figure 6 , the driving process of a single piezoelectric driver includes the following steps:

[0047] a) initial stage, by keeping the pre-tightening force of the piezoelectric ceramic stack by the pre-tightening screw 6 at 10% to 20% of the maximum thrust of the piezoelectric ceramic stack. Before work, by adjusting the tightening degree of the three distance adjusting bolts 5, the friction between the three driving feet 2.3 and the rotary table 3 is equal.

[0048] b) slow extension stage of the piezoelectric ceramic, inputting a sawtooth-shaped electric signal to the piezoelectric stack 1, when the voltage slowly increases, based on the inverse piezoelectric effect, the piezoelectric ceramic stack slowly extends with the slow increase of the voltage, the primary compliant structure 2.1 amplifies the deformation of the piezoelectric stack in the y direction, the secondary compliant structure 2.2 makes the driving foot 2.3 press the inner circumferential surface of the rotary table 3 in the radial direction, increases the pressure and static friction between the driving foot 2.3 and the rotary table 3, so that the sliding phenomenon between the driving foot 2.3 and the rotary table 3 is not easy to occur, and the relative static between the two is ensured. At the same time, the secondary compliant structure 2.2 deforms, so that the driving foot 2.3 forms a tangential displacement, and drives the rotary table 3 to move d1 distance in the positive direction of the tangential direction.

[0049] c) fast contraction stage of the piezoelectric ceramic stack, when the voltage amplitude sharply decreases to 0V, the piezoelectric ceramic stack 1 quickly shortens with the rapid decrease of the sawtooth wave voltage, and returns to the initial length, the primary compliant structure 2.1 and the secondary compliant structure 2.2 reset, the driving foot 2.3 will rapidly retreat in the radial direction and the tangential direction at the same time, reducing the pressure and friction between the driving foot 2.3 and the rotary table 3, so that the sliding phenomenon between the two is more likely to occur, and at the same time, the rotary table 3 itself has inertia, which also reduces the back-off movement of the rotary table 3 in the negative direction of the tangential direction.

[0050] And, by adjusting the phase difference of the three groups of piezoelectric stack drive signals, the backoff can be suppressed. Specifically, because the sawtooth wave signals input to the three piezoelectric ceramic stacks are staggered by one-third of a period, when one of the piezoelectric drivers backtracks, the other two piezoelectric drivers are in the stage of elongation, pushing the turntable to rotate in the positive direction; see specifically Figure 7 At time t1 and time t2 in FIG. 1, the piezoelectric ceramic stacks a, b, and c are all in the stage of slow elongation, jointly pushing the turntable 3 to move; at time t2, the piezoelectric ceramic stack a rapidly contracts, which will cause the turntable 3 to back off, but the piezoelectric ceramic stacks b and c are both in the stage of slow elongation, and under the joint action of the three, the turntable 3 still moves in the positive direction. In addition, the parallel connection of the three drivers also improves the driving force on the turntable 3, reduces the backtracking effect of the turntable 3, and thus improves the load capacity of the rotating mechanism.

[0051] Therefore, the backtracking displacement d2 of the turntable caused by the reset of a single piezoelectric driver is close to 0; the final displacement of the turntable 3 in one sawtooth wave period is d1-d2, where d1>>d2; and d2 can be ignored; by continuously applying a periodic sawtooth wave, the turntable 3 can continuously rotate.

Claims

1. A piezoelectric rotary drive platform based on a stick-slip mechanism, comprising a turntable (3), a stator (2), a fixed shaft (4), and a base (7); characterized in that: The fixed shaft (4) is fixed on the base (7); the stator (2) is fixed on the outside of the fixed shaft (4); the turntable (3) is coaxially rotatably connected to the fixed shaft (4); the stator (2) is provided with n piezoelectric actuators arranged sequentially along the circumference of the fixed shaft (4); n≥3; the outside of the stator (2) is provided with n actuator mounting positions; the actuator mounting positions include limiting surfaces and connecting parts; The piezoelectric actuator includes a piezoelectric ceramic stack (1), a primary compliant structure (2.1), a secondary compliant structure (2.2), and a driving foot (2.3); the inner end of the primary compliant structure (2.1) is connected to the outer end of the corresponding connecting part by a flexible hinge; a push plate is connected to the middle of the inner side of the primary compliant structure (2.1) by a flexible hinge; the piezoelectric ceramic stack (1) is disposed between the push plate and the corresponding stator (2); The secondary compliant structure (2.2) is located at the outer end of the outer side of the primary compliant structure (2.1); the secondary compliant structure (2.2) includes two connecting arms and one mounting arm; the inner ends of the two parallel and equal-length connecting arms are connected to the primary compliant structure (2.1); the outer ends of the two connecting arms are connected to the two ends of the mounting arm respectively; the outer side of the mounting arm is fixed with a driving foot (2.3).

2. The piezoelectric rotary drive platform based on a stick-slip mechanism according to claim 1, characterized in that: Each piezoelectric ceramic stack (1) corresponds to a preload bolt; the preload bolt is screwed onto the stator (2) and abuts against the inner end of the piezoelectric ceramic stack (1); the preload bolt applies a preload to the piezoelectric ceramic stack (1).

3. The piezoelectric rotary drive platform based on a stick-slip mechanism according to claim 2, characterized in that: The inner side of the connecting part is perpendicular to the limiting surface; the connecting part and the main body of the stator (2) are integrally formed; the inner end of the first-level compliant structure (2.1) is connected to the outer end of the connecting part; n piezoelectric actuators are respectively installed in n actuator mounting positions; n second threaded through holes are opened on the stator (2); the n second threaded through holes correspond to the n limiting surfaces respectively; the second threaded through holes pass through the inner circumferential surface of the stator (2) and the corresponding limiting surface; the axis of the second threaded through hole is perpendicular to the corresponding limiting surface; the preload bolt is screwed into the corresponding second threaded through hole.

4. A piezoelectric rotary drive platform based on a stick-slip mechanism according to claim 2 or 3, characterized in that: Gaskets (8) are provided between the outer end of the piezoelectric ceramic stack (1) and the push plate, and between the inner end of the piezoelectric ceramic stack (1) and the corresponding preload bolt.

5. A piezoelectric rotary drive platform based on a stick-slip mechanism according to claim 1, 2, or 3, characterized in that: The outer surface of the drive foot (2.3) is semi-cylindrical and is provided with a friction coating.

6. A piezoelectric rotary drive platform based on a stick-slip mechanism according to claim 1, 2, or 3, characterized in that: The inner side of the drive foot (2.3) is provided with a tenon; the outer side of the mounting arm is provided with a mortise; the drive foot (2.3) is detachably connected by a mortise and tenon structure.

7. A piezoelectric rotary drive platform based on a stick-slip mechanism according to claim 1, 2, or 3, characterized in that: The n piezoelectric actuators on the stator (2) are evenly distributed along the circumference of the fixed shaft (4).

8. A piezoelectric rotary drive platform based on a stick-slip mechanism according to claim 1, 2, or 3, characterized in that: The turntable (3) includes a coaxial and integrally formed central shaft, a top turntable and a rotating ring; the rotating ring is sleeved on the outside of each piezoelectric actuator; deep groove ball bearings (4.1) are embedded at both ends of the central hole of the fixed shaft (4); the central shaft of the turntable (3) passes through two deep groove ball bearings (4.1) and is interference-fitted with the inner ring of the deep groove ball bearings (4.1).

9. A piezoelectric rotary drive platform based on a stick-slip mechanism according to claim 1, 2, or 3, characterized in that: The value of n is 3; the center hole of the stator is fitted on the outside of the fixed shaft; three radial first threaded through holes are provided on the stator (2); the three first threaded through holes and the three piezoelectric actuators are arranged alternately along the circumference of the central axis of the stator (2); the three adjusting bolts (5) are respectively threaded into the first threaded through holes, and their ends abut against the fixed shaft; by rotating the three adjusting bolts (5), the degree of eccentricity between the stator (2) and the turntable and the fixed shaft is adjusted, so that the pressure of the three driving feet on the turntable is suppressed.

10. The driving method for a piezoelectric rotary drive platform based on a stick-slip mechanism as described in claim 1, characterized in that: Periodic sawtooth electrical signals are applied to n piezoelectric actuators respectively; along the rotation direction of the turntable, the sawtooth electrical signals of the n piezoelectric actuators are staggered by 1 / n cycles; one cycle of the periodic electrical signal includes a rising segment and a falling segment; the voltage value of the electrical signal increases linearly from 0 to the maximum value in the rising segment, and decreases linearly from the maximum value to 0 in the falling segment; the duration of the rising segment is greater than or equal to (n-1) times the duration of the falling segment; the piezoelectric actuators push the turntable to rotate in the positive direction in the rising segment, and retract and reset in the falling segment.

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