Piezoelectric stick-slip rotary motor

Abstract

This invention discloses a piezoelectric stick-slip rotary motor, comprising a mover with a first conical pit and a second conical pit, and further comprising a first drive mechanism and a second drive mechanism. The first drive mechanism includes a first annular member and a first rotating member located within the first annular member, and further comprises a first piezoelectric drive assembly and a first flexible connector disposed between the first annular member and the first rotating member. The first rotating member has a first cone inserted into the first conical pit. The second drive mechanism includes a second annular member and a second rotating member located within the second annular member, and further comprises a second piezoelectric drive assembly and a second flexible connector disposed between the second annular member and the second rotating member. The second rotating member has a second cone inserted into the second conical pit. The output directions of the first piezoelectric drive assembly and the second piezoelectric drive assembly are the same after being energized. This invention features simple assembly and adjustment between the mover and stationary elements, can achieve rotational motion exceeding 360°, and provides high driving force and rotational speed.

Description

Technical Field

[0001] This invention belongs to the field of micro-nano positioning technology, and relates to piezoelectric rotary actuators, and particularly to a piezoelectric stick-slip rotary motor. Background Technology

[0002] Piezoelectric stick-slip rotary motors are precision rotary displacement actuators capable of achieving both large strokes (360° rotation) and high resolution at the micro-nano level. They utilize the difference in dynamic and static friction between the mover and stator caused by the asymmetric vibration of the piezoelectric actuator under sawtooth wave voltage, continuously accumulating the small displacements of the piezoelectric actuator to achieve a continuous large stroke displacement. Compared to electromagnetic rotary motors, piezoelectric stick-slip rotary motors offer advantages such as no magnetic field, ease of control, and absence of end effects and thrust fluctuations. Compared to ultrasonic resonant and inchworm-driven piezoelectric rotary motors, they offer advantages such as ease of miniaturization, simple drive control, and negligible hysteresis nonlinearity during rapid motion. Therefore, piezoelectric stick-slip rotary motors exhibit unique advantages in micro-nano manipulation technologies requiring miniaturization, lightweight design, and no magnetic field, such as MEMS assembly and cell manipulation. However, current piezoelectric stick-slip rotary motors still have the following shortcomings:

[0003] 1) The motor is large in size and has a complex structure;

[0004] 2) The assembly and adjustment process between the stationary and moving parts is complex;

[0005] 3) It is difficult to achieve rotational motion exceeding 360°;

[0006] 4) The motor has a large angular displacement, but low speed and driving force. Summary of the Invention

[0007] The technical problem to be solved by the present invention is to provide a piezoelectric stick-slip rotary motor with a reasonable structural layout, simple assembly and adjustment between the stationary and moving parts, capable of achieving more than 360° rotational motion, and large driving force and speed, in light of the current status of the prior art.

[0008] The technical solution adopted by the present invention to solve the above-mentioned technical problems is as follows: a piezoelectric stick-slip rotary motor, including a mover as an output component, the mover having a first conical pit and a second conical pit, the first conical pit and the second conical pit having opposite orientations and being coaxial; a first driving mechanism is provided on the outside of the first conical pit, and a second driving mechanism is provided on the outside of the second conical pit;

[0009] The first drive mechanism includes a first annular component and a first rotating component located within the first annular component. It also includes a first piezoelectric drive assembly and a first flexible connector disposed between the first annular component and the first rotating component. The first rotating component is provided with a first cone inserted into a first conical pit.

[0010] The second drive mechanism includes a second annular member and a second rotating member located within the second annular member. It also includes a second piezoelectric drive assembly and a second flexible connector disposed between the second annular member and the second rotating member. The second rotating member is provided with a second cone inserted into a second conical pit.

[0011] The output directions of the first and second piezoelectric drive groups are the same after they are energized.

[0012] The first piezoelectric drive unit drives the first rotating component to rotate, and the first rotating component synchronously drives the first cone to rotate. The first cone drives the mover to rotate through the static friction between itself and the first conical pit. The second piezoelectric drive unit drives the second rotating component to rotate, and the second rotating component synchronously drives the second cone to rotate. The second cone drives the mover to rotate through the static friction between itself and the second conical pit.

[0013] When the mover needs to rotate continuously, a voltage is applied to the first piezoelectric drive group. The voltage intensity slowly rises from 0 to the peak value, and the first cone slowly drives the mover to rotate. After the voltage reaches the peak value, it quickly drops to 0, and the first cone quickly resets, repeating the cycle. The waveform of the voltage applied by the second piezoelectric drive group is the same as that of the first piezoelectric drive group. The difference is that the second piezoelectric drive group applies voltage when the voltage of the first piezoelectric drive group is rising from 0 to the peak value. This ensures that when the first cone resets, the second cone still drives the mover to rotate. Similarly, in the next cycle, when the second cone resets, the first cone still drives the mover to rotate. Finally, the mover rotates a certain angle in the positive direction within one cycle. Repeating the above steps can achieve continuous rotation of the motor, and the continuously rotating second cone can correct the backlash error of the mover when the first cone resets.

[0014] To optimize the above technical solution, the following measures were also taken:

[0015] As a further optimization of the present invention, the first annular component is provided with a first base, and the second annular component is provided with a second base. The first base and the second base are placed together on the base. The first base is provided with a slotted hole leading to the base, and the second base is provided with a countersunk hole leading to the base. A first fastening screw is installed in the slotted hole, and a second fastening screw is installed in the countersunk hole. By loosening the first fastening screw, the first base can move on the base, thereby adjusting the distance between the first cone and the first conical pit, and adjusting the distance between the second cone and the second conical pit.

[0016] As a further optimization of the present invention, a first through hole is provided between the first conical pit and the second conical pit, and the first cone is provided with a motor shaft, with the first through hole gap sleeved outside the motor shaft; the second cone and the second rotating member are provided with a second through hole for powering the motor shaft to rotate. The motor shaft can ensure the coaxiality of the first cone and the second cone, and facilitates the accurate positioning of the moving part during device installation.

[0017] As a further optimization of the present invention, the end of the motor shaft is provided with a threaded section and equipped with a preload nut. A bearing and a washer are sequentially arranged between the preload nut and the second annular member, and the bearing is sleeved on the motor shaft. Tightening the preload nut can push the bearing to move towards the first drive mechanism, thereby reducing the distance between the first drive mechanism and the second drive mechanism, and ultimately increasing the friction between the first cone and the first conical recess, as well as between the second cone and the second conical recess.

[0018] As a further optimization of the present invention, the washer is placed on the outer ring of the bearing, and the preload nut is placed on the inner ring of the bearing, so that the preload nut can rotate together with the motor shaft.

[0019] As a further optimization of the present invention, the first piezoelectric drive assembly includes a first pre-tightening washer, a first piezoelectric actuator, and a first hemispherical head arranged sequentially. The first annular member is provided with a first stepped portion for placing the first pre-tightening washer, and the first rotating member is provided with a second stepped portion for the first hemispherical head to abut against. When the first piezoelectric actuator is energized and extends, it can drive the first rotating member to rotate through the first hemispherical head. The first hemispherical head can prevent the first piezoelectric actuator from being damaged by lateral pressure.

[0020] The second piezoelectric drive assembly includes a second preload washer, a second piezoelectric actuator, and a second hemispherical head, which are sequentially mounted on top of each other. The second annular member has a third step for placing the second preload washer, and the second rotating member has a fourth step for the second hemispherical head to hold against. When the second piezoelectric actuator is energized and extends, it can drive the second rotating member to rotate through the second hemispherical head. The second hemispherical head can prevent the second piezoelectric actuator from being damaged by lateral pressure.

[0021] The first and second piezoelectric actuators are tilted, and the tilting direction and angle are the same on the same projection. This way, when the first and second piezoelectric actuators are energized in sequence, the mover can rotate in the same direction.

[0022] As a further optimization of the present invention, the first annular member is provided with a first preload screw pressing on the first preload washer, and the second annular member is provided with a second preload screw pressing on the second preload washer.

[0023] As a further optimization of the present invention, the first flexible connector includes a first circumferential flexible hinge located on the first annular member, and a first radial flexible hinge connecting the first circumferential flexible hinge and the first rotating member. The first annular member is provided with a first buffer groove to accommodate the first circumferential flexible hinge. The first circumferential flexible hinge is mounted on the first buffer groove along the circumference of the first annular member. The first radial flexible hinge connects the first rotating member and the middle section of the first circumferential flexible hinge, making the first radial flexible hinge and the first circumferential flexible hinge form a T-shape. The advantages of the T-shaped structure of the first flexible connector are: the first circumferential flexible hinge can buffer the radial pulling impact of the first radial flexible hinge, while the first radial flexible hinge can help the first rotating member rotate and reset.

[0024] The second flexible connector includes a second circumferential flexible hinge located on the second annular member, and a second radial flexible hinge connecting the second circumferential flexible hinge and the second rotating member. The second annular member has a second buffer groove for accommodating the second circumferential flexible hinge. The second circumferential flexible hinge is mounted circumferentially on the second buffer groove along the second annular member. The second radial flexible hinge connects the middle sections of the second rotating member and the second circumferential flexible hinge, forming a T-shape. The advantages of the T-shaped structure of the second flexible connector are: the second circumferential flexible hinge can buffer the radial tensile impact of the second radial flexible hinge, while the second radial flexible hinge can help the second rotating member rotate and reset.

[0025] As a further optimization of the present invention, the first rotating member is provided with a third buffer groove into which the first radial flexible hinge penetrates, and the second rotating member is provided with a fourth buffer groove into which the second radial flexible hinge penetrates. One end of the first radial flexible hinge is connected to the middle section of the first circumferential flexible hinge, and the other end is connected to the bottom of the third buffer groove. One end of the second radial flexible hinge is connected to the middle section of the second circumferential flexible hinge, and the other end is connected to the bottom of the fourth buffer groove. Compared to being connected to the outside of the first rotating member, the first radial flexible hinge is closer to the center of the first rotating member, allowing it to be longer and enabling the first rotating member to rotate at a larger angle. Similarly, the second rotating member can rotate at a larger angle.

[0026] As a further optimization of the present invention, the second annular member is provided with a mounting hole for accommodating a washer and a bearing.

[0027] In summary, compared with the prior art, the piezoelectric stick-slip rotary motor of the present invention has the following advantages:

[0028] 1) The motor is small in size and has a simple and compact structure;

[0029] 2) The friction between the stator and the motor can be changed through simple adjustments;

[0030] 3) The motor can achieve rotational motion exceeding 360°;

[0031] 4) The motor adopts a dual-drive method, which can not only reduce the rotational displacement, but also increase the motor speed and increase the driving force. Attached Figure Description

[0032] Figure 1 This is a schematic diagram of the structure of the present invention;

[0033] Figure 2 This is a three-dimensional structural schematic diagram of the present invention;

[0034] Figure 3 yes Figure 1 Internal structure diagram;

[0035] Figure 4 yes Figure 2 Internal structure diagram;

[0036] Figure 5 yes Figure 3 A schematic diagram of the decomposition process;

[0037] Figure 6 yes Figure 1 A schematic diagram of the first drive mechanism from the left-center view;

[0038] Figure 7 yes Figure 6 A schematic diagram of the decomposition process;

[0039] Figure 8 Is and Figure 6 A schematic diagram of the first drive mechanism from the same perspective;

[0040] Figure 9 yes Figure 8 A schematic diagram of the decomposition process;

[0041] Figure 10 This is a driving waveform diagram of the first and second piezoelectric actuators of the present invention. Detailed Implementation

[0042] The embodiments of the present invention will be described in further detail below with reference to the accompanying drawings.

[0043] Figures 1 to 9 This is a schematic diagram of the structure of the present invention.

[0044] The reference numerals in the accompanying drawings are as follows: First drive mechanism 1, First annular component 11, First stepped portion 111, First buffer groove 112, First rotating component 12, Second stepped portion 121, Third buffer groove 122, First flexible connector 13, First radial flexible hinge 131, First circumferential flexible hinge 132, First piezoelectric drive assembly 14, First preload washer 141, First piezoelectric actuator 142, First hemispherical head 143, First preload screw 15, First cone 16, Motor shaft 17, Threaded section 171, First base 18, Slotted hole 181, Second drive mechanism 2, Second annular component 21, Third stepped portion 211, ... 212, second buffer groove, second rotating part, fourth step, fourth buffer groove, second flexible connector, second radial flexible hinge, second circumferential flexible hinge, second piezoelectric drive assembly, second preload washer, second piezoelectric actuator, second hemispherical head, second preload screw, second cone, second through hole, second base, countersunk hole, mounting hole, moving part, first conical pit, second conical pit, first through hole, first fastening screw, second fastening screw, second fastening screw, washer, bearing, preload nut, base, and base.

[0045] Figures 1 to 9 As shown in the figure, the piezoelectric stick-slip rotary motor of the present invention includes a mover 3 as an output component. The mover 3 is provided with a first conical pit 31 and a second conical pit 32. The first conical pit 31 and the second conical pit 32 are oriented in opposite directions and are coaxial. A first drive mechanism 1 is provided on the outside of the first conical pit 31, and a second drive mechanism 2 is provided on the outside of the second conical pit 32.

[0046] The first drive mechanism 1 includes a first annular member 11 and a first rotating member 12 located within the first annular member 11. It also includes a first piezoelectric drive group 14 and a first flexible connector 13 disposed between the first annular member 11 and the first rotating member 12. The first rotating member 12 is provided with a first cone 16 inserted into the first conical pit 31.

[0047] The second drive mechanism 2 includes a second annular member 21 and a second rotating member 22 located within the second annular member 21. It also includes a second piezoelectric drive assembly 24 and a second flexible connector 23 disposed between the second annular member 21 and the second rotating member 22. The second rotating member 22 is provided with a second cone 26 inserted into the second conical pit 32.

[0048] The first piezoelectric drive group 14 and the second piezoelectric drive group 24 have the same output direction after being energized.

[0049] The first piezoelectric drive group 14 drives the first rotating member 12 to rotate, and the first rotating member 12 synchronously drives the first cone 16 to rotate. The first cone 16 drives the mover 3 to rotate through the static friction between itself and the first conical pit 31. The second piezoelectric drive group 24 drives the second rotating member 22 to rotate, and the second rotating member 22 synchronously drives the second cone 26 to rotate. The second cone 26 drives the mover 3 to rotate through the static friction between itself and the second conical pit 32.

[0050] In the embodiments, such as Figures 1 to 5 As shown, the first annular component 11 has a first base 18, and the second annular component 21 has a second base 28. The first base 18 and the second base 28 are placed together on the base 9. The first base 18 has a slotted hole 181 leading to the base 9, and the second base 28 has a countersunk hole 281 leading to the base 9. A first fastening screw 4 is installed in the slotted hole 181, and a second fastening screw 5 is installed in the countersunk hole 281. By loosening the first fastening screw 4, the first base 18 can move on the base 9, thereby adjusting the distance between the first cone 16 and the first conical pit 31, and adjusting the distance between the second cone 26 and the second conical pit 32.

[0051] In the embodiments, such as Figure 5 As shown, a first through hole 33 is provided between the first conical pit 31 and the second conical pit 32. The first cone 16 is provided with a motor shaft 17, and the first through hole 33 is fitted around the outside of the motor shaft 17. The second cone 26 and the second rotating member 22 are provided with a second through hole 27 for rotating the motor shaft 17. The motor shaft 17 can ensure the coaxiality of the first cone 16 and the second cone 26, and facilitate the accurate positioning of the mover 3 during device installation.

[0052] In the embodiments, such as Figure 5 As shown, the end of the motor shaft 17 is provided with a threaded section 171 and a preload nut 8. A bearing 7 and a washer 6 are sequentially arranged between the preload nut 8 and the second annular member 21. The bearing 7 is sleeved on the motor shaft 17. Tightening the preload nut 8 can push the bearing 7 to move towards the first drive mechanism 1, thereby reducing the distance between the first drive mechanism 1 and the second drive mechanism 2, and ultimately increasing the friction between the first cone 16 and the first conical pit 31, and between the second cone 26 and the second conical pit 32.

[0053] In the embodiments, such as Figure 3 As shown, washer 6 rests on the outer ring of bearing 7, and preload nut 8 rests on the inner ring of bearing 7, so that preload nut 8 can rotate together with motor shaft 17.

[0054] In the embodiments, such as Figure 6 and Figure 7As shown, the first piezoelectric drive assembly 14 includes a first pre-tightening pad 141, a first piezoelectric actuator 142, and a first hemispherical head 143, which are sequentially mounted on top of each other. The first annular member 11 is provided with a first step portion 111 for placing the first pre-tightening pad 141, and the first rotating member 12 is provided with a second step portion 121 for the first hemispherical head 143 to abut against. When the first piezoelectric actuator 142 is energized and extends, it can push the first rotating member 12 to rotate through the first hemispherical head 143. The first hemispherical head 143 can prevent the first piezoelectric actuator 142 from being damaged by lateral pressure.

[0055] like Figure 8 and Figure 9 As shown, the second piezoelectric drive assembly 24 includes a second preload pad 241, a second piezoelectric actuator 242, and a second hemispherical head 243, which are sequentially mounted on top of each other. The second annular member 21 is provided with a third step portion 211 for placing the second preload pad 241, and the second rotating member 22 is provided with a fourth step portion 221 for the second hemispherical head 243 to abut against. When the second piezoelectric actuator 242 is energized and extends, it can push the second rotating member 22 to rotate through the second hemispherical head 243. The second hemispherical head 243 can prevent the second piezoelectric actuator 242 from being damaged by lateral pressure.

[0056] The first piezoelectric actuator 142 and the second piezoelectric actuator 242 are inclined and have the same tilt direction and angle on the same projection. In this way, after the first piezoelectric actuator 142 and the second piezoelectric actuator 242 are energized in sequence, the mover 3 can be rotated in the same direction.

[0057] In the embodiments, such as Figure 6 and Figure 7 As shown, the first annular member 11 is provided with a first preload screw 15 that rests on the first preload washer 141, as... Figure 8 and Figure 9 As shown, the second annular member 21 is provided with a second preload screw 25 that rests on the second preload washer 241.

[0058] In the embodiments, such as Figure 6 and Figure 7As shown, the first flexible connector 13 includes a first circumferential flexible hinge 132 located on the first annular member 11, and a first radial flexible hinge 131 connecting the first circumferential flexible hinge 132 and the first rotating member 12. The first annular member 11 is provided with a first buffer groove 112 to accommodate the first circumferential flexible hinge 132. The first circumferential flexible hinge 132 is mounted circumferentially on the first buffer groove 112 along the first annular member 11. The first radial flexible hinge 131 connects the first rotating member 12 and the middle section of the first circumferential flexible hinge 132, making the first radial flexible hinge 131 and the first circumferential flexible hinge 132 form a T-shape. The advantages of the T-shaped structure of the first flexible connector 13 are: the first circumferential flexible hinge 132 can buffer the radial pulling impact of the first radial flexible hinge 131, while the first radial flexible hinge 131 can help the first rotating member 12 rotate and reset.

[0059] like Figure 8 and Figure 9 As shown, the second flexible connector 23 includes a second circumferential flexible hinge 232 located on the second annular member 21, and a second radial flexible hinge 231 connecting the second circumferential flexible hinge 232 and the second rotating member 22. The second annular member 21 is provided with a second buffer groove 212 to accommodate the second circumferential flexible hinge 232. The second circumferential flexible hinge 232 is mounted circumferentially on the second buffer groove 212 along the second annular member 21. The second radial flexible hinge 231 connects the middle section of the second rotating member 22 and the second circumferential flexible hinge 232, making the second radial flexible hinge 231 and the second circumferential flexible hinge 232 form a T-shape. The advantages of the T-shaped structure of the second flexible connector 23 are: the second circumferential flexible hinge 232 can buffer the radial pulling impact of the second radial flexible hinge 231, while the second radial flexible hinge 231 can help the second rotating member 22 rotate and reset.

[0060] In the embodiments, such as Figure 6 and Figure 7 As shown, the first rotating member 12 is provided with a third buffer groove 122 into which the first radial flexible hinge 131 penetrates, such as Figure 8 and Figure 9 As shown, the second rotating member 22 is provided with a fourth buffer groove 222 into which the second radial flexible hinge 231 enters. One end of the first radial flexible hinge 131 is connected to the middle section of the first circumferential flexible hinge 132, and the other end is connected to the bottom of the third buffer groove 122. One end of the second radial flexible hinge 231 is connected to the middle section of the second circumferential flexible hinge 232, and the other end is connected to the bottom of the fourth buffer groove 222. Compared to being connected to the outside of the first rotating member 12, the first radial flexible hinge 131 is closer to the center of the first rotating member 12, and the first radial flexible hinge 131 can be longer, allowing the first rotating member 12 to rotate at a larger angle. Similarly, the second rotating member 22 can rotate at a larger angle.

[0061] In the embodiments, such as Figure 5 As shown, the second annular member 21 is provided with a mounting hole 29 for accommodating the washer 6 and the bearing 7.

[0062] If, when viewed from the first piezoelectric drive group 14 towards the second piezoelectric drive group 24, the movement of the mover 3 is clockwise (positive rotation), then the working principle of this invention is as follows:

[0063] like Figure 10 As shown, the voltage applied to the first piezoelectric actuator 142 exhibits a sawtooth waveform. At time t10, the voltage is slowly applied to the first piezoelectric actuator 142. At time t11, the first piezoelectric actuator 142 is de-energized and quickly retracts, resetting the first drive mechanism 1. The cycle repeats at time t12 after the reset is complete. The voltage waveform applied to the second piezoelectric actuator 242 is the same as that of the first piezoelectric actuator 142, except that the voltage is applied by the second piezoelectric actuator 242 during the voltage increase process of the first piezoelectric actuator 142. Ultimately, the mover 3 rotates forward by a certain angle within one cycle. Repeating the above steps achieves continuous rotational motion of the mover. If reversal is required, the voltage is applied quickly and then slowly reduced.

[0064] The preferred embodiments of the present invention have been described, and various changes or modifications made by those skilled in the art will not depart from the scope of the present invention.

Claims

1. Piezoelectric stick-slip rotary electric machine comprising a rotor (3), characterized in that, The moving part (3) is provided with a first conical pit (31) and a second conical pit (32), the first conical pit (31) and the second conical pit (32) are oriented in opposite directions and are coaxial; a first driving mechanism (1) is provided on the outside of the first conical pit (31), and a second driving mechanism (2) is provided on the outside of the second conical pit (32); The first driving mechanism (1) includes a first annular member (11) and a first rotating member (12) located within the first annular member (11), and also includes a first piezoelectric drive group (14) and a first flexible connector (13) disposed between the first annular member (11) and the first rotating member (12). The first rotating member (12) is provided with a first cone (16) inserted into the first conical pit (31). The second drive mechanism (2) includes a second annular member (21) and a second rotating member (22) located within the second annular member (21), and also includes a second piezoelectric drive assembly (24) and a second flexible connector (23) disposed between the second annular member (21) and the second rotating member (22). The second rotating member (22) is provided with a second cone (26) inserted into a second conical pit (32). The first piezoelectric drive group (14) and the second piezoelectric drive group (24) have the same output direction after being energized; The first piezoelectric drive assembly (14) includes a first preloaded washer (141), a first piezoelectric actuator (142), and a first hemispherical head (143) arranged sequentially. The first annular member (11) is provided with a first step portion (111) for placing the first preloaded washer (141), and the first rotating member (12) is provided with a second step portion (121) for the first hemispherical head (143) to abut against. The second piezoelectric drive assembly (24) includes a second preloaded pad (241), a second piezoelectric actuator (242), and a second hemispherical head (243) that are sequentially mounted. The second annular member (21) is provided with a third step (211) for placing the second preloaded pad (241), and the second rotating member (22) is provided with a fourth step (221) for the second hemispherical head (243) to abut against. The first piezoelectric actuator (142) and the second piezoelectric actuator (242) are tilted, and the tilting direction and angle are the same on the same projection.

2. The piezoelectric stick-slip rotary motor according to claim 1, characterized in that, The first annular component (11) is provided with a first base (18), and the second annular component (21) is provided with a second base (28). The first base (18) and the second base (28) are placed together on the base (9). The first base (18) is provided with a slotted hole (181) leading to the base (9), and the second base (28) is provided with a countersunk hole (281) leading to the base (9). The slotted hole (181) is filled with a first fastening screw (4), and the countersunk hole (281) is filled with a second fastening screw (5).

3. The piezoelectric stick-slip rotary motor according to claim 2, characterized in that, A first through hole (33) is provided between the first conical pit (31) and the second conical pit (32). The first cone (16) is provided with a motor shaft (17). The first through hole (33) is fitted outside the motor shaft (17) with a gap. The second cone (26) and the second rotating member (22) are provided with a second through hole (27) for the motor shaft (17) to rotate.

4. The piezoelectric stick-slip rotary motor according to claim 3, characterized in that, The motor shaft (17) has a threaded section (171) at its end and is equipped with a preload nut (8). A bearing (7) and a washer (6) are sequentially provided between the preload nut (8) and the second annular part (21). The bearing (7) is sleeved on the motor shaft (17).

5. The piezoelectric stick-slip rotary motor according to claim 4, characterized in that, The washer (6) rests on the outer ring of the bearing (7), and the preload nut (8) rests on the inner ring of the bearing (7).

6. The piezoelectric stick-slip rotary motor according to claim 5, characterized in that, The first annular member (11) is provided with a first pre-tightening screw (15) pressing against the first pre-tightening washer (141), and the second annular member (21) is provided with a second pre-tightening screw (25) pressing against the second pre-tightening washer (241).

7. The piezoelectric stick-slip rotary motor according to claim 6, characterized in that, The first flexible connector (13) includes a first circumferential flexible hinge (132) located on the first annular member (11) and a first radial flexible hinge (131) connecting the first circumferential flexible hinge (132) and the first rotating member (12). The first annular member (11) is provided with a first buffer groove (112) for accommodating the first circumferential flexible hinge (132). The second flexible connector (23) includes a second circumferential flexible hinge (232) located on the second annular member (21) and a second radial flexible hinge (231) connecting the second circumferential flexible hinge (232) and the second rotating member (22). The second annular member (21) is provided with a second buffer groove (212) for accommodating the second circumferential flexible hinge (232).

8. The piezoelectric stick-slip rotary motor according to claim 7, characterized in that, The first rotating member (12) is provided with a third buffer groove (122) for the first radial flexible hinge (131) to penetrate, and the second rotating member (22) is provided with a fourth buffer groove (222) for the second radial flexible hinge (231) to penetrate.

9. The piezoelectric stick-slip rotary motor according to claim 8, characterized in that, The second annular member (21) is provided with mounting holes (29) for accommodating washers (6) and bearings (7).

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