A piezoelectric rotary precision drive platform based on parasitic inertia principle

Abstract

The present invention relates to a piezoelectric rotary precision driving platform based on the parasitic inertia principle, comprising two piezoelectric stacks, two asymmetric thin-walled flexible hinge mechanisms, a rotor, a pre-tightening screw, a pre-tightening wedge and a base. The two groups of piezoelectric stacks can be extended and restored under the drive of a voltage signal; the two groups of asymmetric thin-walled flexible hinge mechanisms can realize parasitic inertial motion; the pre-tightening screws and the pre-tightening wedges adjust the initial pre-tightening force between the asymmetric thin-walled flexible hinge mechanism and the rotor; the base plays a supporting role. Under the timing control of the voltage, the two piezoelectric stacks of the present invention alternately provide drive, so that the two groups of asymmetric thin-walled flexible hinge mechanisms alternately drive the rotor to rotate, which not only increases the output load, but also eliminates the retreat phenomenon of the rotor within the motion cycle, improves the output performance of the device, and realizes the efficient rotation of the rotor. The platform can be applied to precision and ultra-precision machining, micro-electromechanical systems, micro-manipulation robots, large-scale integrated circuit manufacturing, and biotechnology.

Description

Technical Field

[0001] The invention relates to the fields of precision and ultra-precision machining, micro-nano operating robots and micro-electromechanical systems, and in particular to a piezoelectric rotary precision driving platform based on the parasitic inertia principle. Background Art

[0002] Precision drive technology with micro / nano-level positioning accuracy is a key technology in high-end scientific and technological fields such as ultra-precision machining and measurement, optical engineering, modern medical care, and aerospace technology. In order to achieve micro / nano-level output accuracy, the application of modern precision drive technology has put forward higher requirements on the accuracy of the drive platform. Traditional drive platforms have low output accuracy and large overall size, which cannot meet the requirements of modern advanced scientific and technological systems for micro / nano-level high precision and small drive platform size. Piezoelectric ceramic drives have the advantages of small size, high displacement resolution, large output load, and high energy conversion rate. They can achieve micro / nano-level output accuracy and have been increasingly used in micro-positioning and precision ultra-precision machining. Existing piezoelectric inertial drive platforms usually place the piezoelectric element and the rotor mass block parallel to their direction of movement. The preload force is perpendicular to the main output direction of the piezoelectric element, and the output load of the overall platform mainly depends on the friction force generated by the preload force. However, piezoelectric elements such as piezoelectric stacks are usually used d 33 The working mode has a small stiffness in the section perpendicular to the main output direction, and the preload generated is small, which greatly reduces the output load of the overall platform. The large stiffness of the piezoelectric element in the main output direction is not fully utilized; the output load provided by a single piezoelectric stack is small; the backlash phenomenon during movement further reduces the output performance. Therefore, it is necessary to design a piezoelectric rotary precision drive platform that fully utilizes the stiffness of the piezoelectric stack in the main output direction, eliminates the backlash phenomenon, increases the output load, and further increases the output load of the piezoelectric drive platform. Summary of the invention

[0003] The purpose of the present invention is to provide a piezoelectric rotary precision drive platform based on the parasitic inertia principle, which solves the above problems existing in the prior art. The present invention has the characteristics of simple and compact structure, high output precision, large output stiffness and output load, high output frequency, and can realize efficient rotary motion output function.

[0004] The present invention adopts two groups of piezoelectric drive units, arranges the main output direction of the piezoelectric stack and the rotation center of the rotor in a straight line, and adopts an asymmetric thin-walled flexible hinge mechanism with good stiffness output characteristics. Under the alternating drive of the two piezoelectric stacks, the asymmetric thin-walled flexible hinge mechanism realizes parasitic inertial motion in sequence, transmits composite loads, and finally realizes the rotational motion of the rotor.

[0005] The above-mentioned object of the present invention is achieved by the following technical solutions:

[0006] A piezoelectric rotary precision drive platform based on the parasitic inertia principle mainly comprises two groups of piezoelectric drive units I and II, a rotor (5), pre-tightening wedges I and II (2, 8), pre-tightening screws I and II (1, 9), and a base (10), characterized in that the precision drive device utilizes the parasitic inertia principle and adopts two groups of drive units to achieve efficient piezoelectric rotary precision drive.

[0007] The piezoelectric drive unit I comprises a piezoelectric stack I (3) and an asymmetric thin-walled flexible hinge mechanism I (4); the piezoelectric drive unit II comprises a piezoelectric stack II (7) and an asymmetric thin-walled flexible hinge mechanism II (6); the piezoelectric stacks I and II (3, 7) are respectively arranged in the asymmetric thin-walled flexible hinge mechanisms I and II (4, 6), and their main output directions are in a straight line with the rotation center of the rotor (5); the piezoelectric stack I (3) can drive the asymmetric thin-walled flexible hinge mechanism I (4) stretches, the piezoelectric stack II (7) can drive the asymmetric thin-walled flexible hinge mechanism II (6) to stretch, and by controlling the timing between driving the piezoelectric stacks I and II (3, 7), the piezoelectric stacks I and II (4, 6) work alternately to achieve the parasitic inertial motion between the asymmetric thin-walled flexible hinge mechanism I and II (4, 6) and the rotor (5), thereby driving the rotational motion of the rotor (5); the rotor (5) includes a rotating table, a bearing and a rotating shaft, the rotating table and the outer ring of the bearing, the rotating shaft and the inner ring of the bearing, and the rotating shaft The rotor (5) is interference fit with the base (10); the structure of the rotor (5) uses a high-precision bearing to reduce its friction loss, and the bearing is connected to the base (10) through a rotating shaft to achieve high-precision rotational motion; the asymmetric thin-walled flexible hinge mechanism I, II (4, 6) is installed on the base (10) through screws; the piezoelectric stack I, II (3, 7) is installed in the asymmetric thin-walled flexible hinge mechanism I, II (4, 6), and its main output direction is in a straight line with the rotation center of the rotor (5). The piezoelectric stacks I and II (3 and 7) can be pre-tightened by pre-tightening wedges I and II (2 and 8). The pre-tightening screws I and II (1 and 9) are fastened to the base (10) and contact the lower ends of the asymmetric thin-walled hinge mechanisms I and II (4 and 6). The asymmetric thin-walled hinge mechanisms I and II (4 and 6) are connected by eight thin-walled flexible hinges to form an asymmetric form, and the arc structure at the upper end contacts the mover (5). The base (10) supports and fixes other parts. The main output direction of the piezoelectric stacks I and II (3 and 7) is in a straight line with the rotation center of the rotor (5), and the stiffness of the main output direction of the piezoelectric stacks I and II (3 and 7) is fully utilized. The asymmetric thin-walled flexible hinge mechanisms I and II (4 and 6) have good stiffness output performance, and the upper end of the asymmetric thin-walled flexible hinge mechanism can withstand a large pre-tightening force, and the movement is stable and efficient.

[0008] The piezoelectric signal uses a sawtooth wave or a triangular wave to control the piezoelectric stacks I and II (3 and 7) in a timing sequence, so that the piezoelectric stacks I and II (3 and 7) are slowly extended in sequence, and the asymmetric thin-walled flexible hinge mechanisms I and II (4 and 6) are pushed to perform parasitic inertial motion respectively, thereby realizing the rotation of the rotor (5); the piezoelectric stacks I and II (3 and 7) are quickly retreated under the control of the piezoelectric signal, and the rotor (5) maintains the angle after rotation under the action of inertia. The two groups of piezoelectric drive units I and II are controlled by timing and work alternately, which can eliminate the retreat phenomenon of the rotor (5) within the motion cycle, greatly increase the output load, and improve the output performance.

[0009] The main advantages of the present invention are: using the principle of parasitic inertial motion, using two groups of piezoelectric drive units to work alternately in a time sequence, eliminating the backlash phenomenon during the motion process; the main output direction of the piezoelectric stack is in a straight line with the rotation center of the rotor, and the parasitic inertial motion of the asymmetric thin-walled flexible hinge mechanism is used to transfer the load; the present invention greatly improves the output load of the drive platform, and at the same time realizes the rotational motion of the rotor, and has the advantages of high drive reliability, good stability, and high work efficiency, and can be applied to important scientific and engineering fields such as precision and ultra-precision machining, micro-manipulation robots, micro-electromechanical systems, large-scale integrated circuit manufacturing, and biotechnology. The present invention has a simple structure, compact layout, stable motion, high efficiency, low investment, and high benefits, and has a broad application prospect. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 is an isometric schematic view of the present invention;

[0011] Figure 2 It is a front view schematic diagram of the present invention;

[0012] Figure 3 It is a left side schematic diagram of the present invention;

[0013] Figure 4 It is a schematic diagram of the asymmetric thin-walled flexible hinge mechanism of the present invention.

[0014] In the figure:

[0015] 1. Preload screw I; 2. Preload wedge I; 3. Piezoelectric stack I;

[0016] 4. Asymmetric thin-walled flexible hinge mechanism I; 5. Rotor; 6. Asymmetric thin-walled flexible hinge mechanism II;

[0017] 7. Piezoelectric stack II; 8. Preload wedge II; 9. Preload screw II;

[0018] 10. Base. DETAILED DESCRIPTION

[0019] The details of the present invention and its specific implementation methods are further described below in conjunction with the accompanying drawings.

[0020] See also Figures 1 to 4 As shown, a piezoelectric rotary precision drive platform based on the parasitic inertia principle mainly includes two groups of piezoelectric drive units I and II, a rotor (5), pre-tightening wedges I and II (2, 8), pre-tightening screws I and II (1, 9), and a base (10), characterized in that: the precision drive device uses the parasitic inertia principle to adopt two groups of drive units to achieve efficient piezoelectric rotary precision drive. The piezoelectric drive unit I includes a piezoelectric stack I (3) and an asymmetric thin-walled flexible hinge mechanism I (4); the piezoelectric drive unit II includes a piezoelectric stack II (7) and an asymmetric thin-walled flexible hinge mechanism II (6); the piezoelectric stacks I and II (3, 7) are respectively arranged in the asymmetric thin-walled flexible hinge mechanism I and II (4, 6), and their main output directions are in a straight line with the rotation center of the rotor (5); the piezoelectric stack I (3) can drive the asymmetric thin-walled flexible hinge mechanism I (4) stretches, and the piezoelectric stack II (7) can drive the asymmetric thin-walled flexible hinge mechanism II (6) to stretch. By controlling the timing between the piezoelectric stacks I and II (3, 7), the piezoelectric stacks I and II (3, 7) work alternately to achieve parasitic inertial motion between the asymmetric thin-walled flexible hinge mechanism I and II (4, 6) and the rotor (5), thereby driving the rotational motion of the rotor (5); the rotor (5) comprises a rotating table, a bearing and a rotating shaft, and the rotating table and the outer ring of the bearing, the rotating shaft and the inner ring of the bearing, and the rotating shaft and the base (10) are interference fit; the structure of the rotor (5) uses high-precision bearings to reduce its friction loss, and the bearing is connected to the base (10) through the rotating shaft to achieve high-precision rotational motion; the asymmetric thin-walled flexible hinge mechanism I and II (4, 6) is installed on the base (10) by screws; the piezoelectric stacks I and II (3, 7) are installed in the asymmetric thin-walled flexible hinge mechanism I and II (4, 6), and their main output direction is in a straight line with the rotation center of the rotor (5). The piezoelectric stacks I and II (3 and 7) can be pre-tightened by pre-tightening wedges I and II (2 and 8); the pre-tightening screws I and II (1 and 9) are fastened to the base (10) and contact the lower ends of the asymmetric thin-walled hinge mechanisms I and II (4 and 6); the asymmetric thin-walled hinge mechanisms I and II (4 and 6) are connected by eight thin-walled flexible hinges to form an asymmetric form, and the arc structure at the upper end thereof contacts the mover (5); the base (10) plays the role of supporting and installing other parts.

[0021] The main output direction of the piezoelectric stacks I, II (3, 7) is in a straight line with the rotation center of the rotor (5), so that the greater stiffness of the piezoelectric stacks I, II (3, 7) in the main output direction is fully utilized; the asymmetric thin-walled flexible hinge mechanism I, II (4, 6) has good stiffness output performance, the upper end of the asymmetric thin-walled flexible hinge mechanism can withstand a large preload, and the movement is stable and efficient.

[0022] The piezoelectric signal uses a sawtooth wave or a triangular wave piezoelectric signal timing control piezoelectric stacks I, II (3, 7), so that the piezoelectric stacks I, II (3, 7) slowly extend in time sequence, and push the asymmetric thin-walled flexible hinge mechanism I, II (4, 6) to perform compound motion respectively, thereby realizing the rotation of the rotor (5); the piezoelectric stacks I, II (3, 7) quickly retreat under the control of the piezoelectric signal, and the rotor (5) maintains the angle after rotation under the action of inertia. The two groups of piezoelectric drive units I and II work alternately through timing control, which can eliminate the retreat phenomenon of the rotor (5) within the movement cycle, greatly increase the output load, and improve the output performance.

[0023] See also Figures 1 to 4 As shown, the specific working process of the present invention is as follows:

[0024] The realization of the step-by-step rotational motion of the rotor, initial state: the preload screws I, II (1, 9) are adjusted respectively to adjust the contact distance between the asymmetric thin-walled flexible hinge mechanism I, II (4, 6) and the rotor (5), that is, the initial preload force during the parasitic motion process. The piezoelectric signal in the form of a sawtooth wave or a triangular wave is used to control the piezoelectric stack I, II (3, 7). When the piezoelectric stacks I and II (3, 7) are not energized, the system is in a free state; when only the piezoelectric stack I (3) is energized, it stretches due to the inverse piezoelectric effect, pushing the asymmetric thin-walled flexible hinge mechanism I (4) to deform, the asymmetric thin-walled flexible hinge mechanism I (4) presses the rotor (5), and the asymmetric thin-walled flexible hinge mechanism I (4) drives the rotor (5) to rotate under the action of the static friction force between the asymmetric thin-walled flexible hinge mechanism I (4) and the rotor (5); when the piezoelectric stack I (3) is about to lose power, the piezoelectric stack II (7) is energized and stretches, pushing the asymmetric thin-walled flexible hinge mechanism II (6) to deform, the asymmetric thin-walled flexible hinge mechanism II (6) presses the rotor (5), and the asymmetric thin-walled flexible hinge mechanism II (6) drives the rotor (5) to continue rotating under the action of the static friction force between the asymmetric thin-walled flexible hinge mechanism II (6). When the piezoelectric stack II (7) is about to lose power, the piezoelectric stack I (3) is powered on and stretched again, driving the asymmetric thin-walled flexible hinge mechanism I (4) to perform parasitic inertial motion, and starting the next cycle of motion cycle. In this process, when the piezoelectric stack I (3) returns to its initial position after losing power, the asymmetric thin-walled flexible hinge mechanism I (4) also returns to its initial state. Similarly, when the piezoelectric stack II (7) quickly returns to its initial position after losing power, the asymmetric thin-walled flexible hinge mechanism II (6) also returns to its initial state. By repeating the above process, the drive platform can achieve efficient rotational motion and obtain a larger output rotation angle.

[0025] The present invention relates to a piezoelectric rotary precision driving platform based on the principle of parasitic inertia, which adopts two groups of piezoelectric stacks as driving sources and an asymmetric thin-walled flexible hinge mechanism as a power transmission element. It has the characteristics of low heat generation, stable, reliable and efficient driving, and can realize functions such as efficient rotary precision motion.

Claims

1. A piezoelectric rotary precision drive platform based on the parasitic inertia principle, comprising two groups of piezoelectric drive units I and II, a rotor (5), pre-tightening wedges I and II (2, 8), pre-tightening screws I and II (1, 9), and a base (10), characterized in that: The precision driving platform uses the parasitic inertia principle and adopts two groups of driving units to realize efficient piezoelectric rotation precision driving; the piezoelectric driving unit I includes a piezoelectric stack I (3) and an asymmetric thin-walled flexible hinge mechanism I (4); the piezoelectric driving unit II includes a piezoelectric stack II (7) and an asymmetric thin-walled flexible hinge mechanism II (6); the piezoelectric stacks I and II (3, 7) are respectively arranged in the asymmetric thin-walled flexible hinge mechanism I and II (4, 6); the piezoelectric stack I (3) can drive the asymmetric thin-walled flexible hinge mechanism I (4) to extend; the piezoelectric stack II (7) can drive the asymmetric thin-walled flexible hinge mechanism II (6) to extend; by controlling the timing between driving the piezoelectric stacks I and II (3, 7), the piezoelectric stacks work alternately, and the parasitic inertial motion between the asymmetric thin-walled flexible hinge mechanism I and II (4, 6) and the rotor (5) is realized, thereby driving the rotation motion of the rotor (5); the rotor (5) includes a rotating table, a bearing and a rotating The shaft, the rotating table and the outer ring of the bearing, the rotating shaft and the inner ring of the bearing, and the rotating shaft and the base (10) are interference fit; the structure of the rotor (5) uses a high-precision bearing to reduce its friction loss, and the bearing is connected to the base (10) through the rotating shaft to achieve high-precision rotational motion; the asymmetric thin-walled flexible hinge mechanism I, II (4, 6) is installed on the base (10) through screws; the piezoelectric stack I, II (3, 7) can be pre-tightened by pre-tightening wedges I, II (2, 8); the pre-tightening screws I, II (1, 9) can adjust the initial pre-tightening force between the asymmetric thin-walled flexible hinge mechanism I, II (4, 6) and the rotor (5); the asymmetric thin-walled flexible hinge mechanism I, II (4, 6) can be made of spring steel or high-strength aluminum alloy, and are connected by eight thin-walled flexible hinges to form an asymmetric parallelogram structure; the main output direction of the piezoelectric stack I, II (3, 7) is on a straight line with the rotation center of the rotor (5).

2. The piezoelectric rotary precision drive platform based on the parasitic inertia principle according to claim 1 is characterized in that The parasitic inertia driving principle of the asymmetric thin-walled flexible hinge mechanism I, II (4, 6) is adopted, and the single piezoelectric stacks I, II (3, 7) are respectively and orderly powered to drive the asymmetric thin-walled flexible hinge mechanism I, II (4, 6) to generate a composite force in two directions. The force in one direction acts as a driving force to drive the rotor (5) to rotate, and the force in the other direction presses the rotor (5) upward to apply a pre-tightening force.

3. The piezoelectric rotary precision drive platform based on the parasitic inertia principle according to claim 1 is characterized in that By controlling the timing of the two groups of piezoelectric drive units I and II, the drive voltage is alternately provided. When only the piezoelectric stack I (3) is energized, the piezoelectric stack I (3) is extended, and the parasitic inertial motion of the asymmetric thin-walled flexible hinge mechanism I (4) is used to drive the rotor (5) to rotate. When the piezoelectric stack I (3) is about to lose power, the piezoelectric stack II (7) is energized and extended, and the parasitic inertial motion of the asymmetric thin-walled flexible hinge mechanism II (6) is used to drive the rotor (5) to continue rotating. In this process, when the piezoelectric stack I (3) returns to its initial position after losing power, the asymmetric thin-walled flexible hinge mechanism I (4) also returns to its initial state. Similarly, when the piezoelectric stack II (7) quickly returns to its initial position after losing power, the asymmetric thin-walled flexible hinge mechanism II (6) also returns to its initial state.

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