A piezoelectric rotary precision drive platform based on parasitic inertia principle

Abstract

The present invention relates to a parasitic inertia type piezoelectric rotary precision driving platform, which is composed of a piezoelectric stack, an asymmetric thin-walled flexible hinge mechanism, a rotor, a pre-tightening screw, a pre-tightening wedge and a base. The piezoelectric stack can be extended and restored under the drive of a voltage signal, and the asymmetric thin-walled flexible hinge mechanism can realize parasitic inertial motion; the pre-tightening screw adjusts the initial pre-tightening force between the asymmetric thin-walled flexible hinge mechanism and the rotor; the base supports and installs and fixes other parts. The main output direction of the piezoelectric stack of the present invention is in a straight line with the rotation center of the rotor, and the stiffness of the main output direction of the piezoelectric stack is fully utilized; the asymmetric thin-walled flexible hinge mechanism has good stiffness and can withstand a large load, thereby increasing the output load of the driving platform. The platform can realize rotational stepping motion along a certain direction, and 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 device. Traditional drive devices 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 size of drive devices. 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 devices usually place the piezoelectric element and the mover 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 device 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 device, and the large stiffness of the piezoelectric element in the main output direction is not fully utilized. 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 and further improves the output load of the piezoelectric drive device. 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 the function of rotary motion output.

[0004] The present invention arranges the main output direction of the piezoelectric stack and the rotor rotation center in a straight line, adopts an asymmetric thin-walled flexible hinge mechanism with good stiffness output characteristics, transmits the composite load through the asymmetric thin-walled flexible hinge mechanism, and finally realizes the rotational movement 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 a rotor (1), a piezoelectric stack (2), a preload wedge (3), a preload screw (4), an asymmetric thin-walled flexible hinge mechanism (5) and a base (6), wherein the precision drive platform realizes piezoelectric rotary precision drive through the parasitic inertia principle. The structure of the rotor (1) uses a high-precision bearing to reduce its friction loss, and the bearing is connected to the base through a rotating shaft; the rotor (1) 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 are interference fit; the asymmetric thin-walled flexible hinge mechanism (5) is installed on the base through screws; the piezoelectric stack (2) is installed in the asymmetric thin-walled flexible hinge mechanism (5), and its main output direction is in a straight line with the rotation center of the rotor (1); the preload wedge (3) is arranged between the piezoelectric stack (2) and the asymmetric thin-walled flexible hinge mechanism (5), and ... The symmetrical thin-walled flexible hinge mechanism (5) can be pre-tightened by a pre-tightening wedge (3); the pre-tightening screw (4) is fastened on the base and contacts the lower end of the asymmetrical thin-walled hinge. The asymmetrical thin-walled flexible hinge mechanism (5) is an asymmetrical thin-walled structure, and its upper arc structure contacts the rotor (1); the base (6) plays the role of supporting and installing and fixing other parts. The asymmetrical thin-walled flexible hinge mechanism (5) is made of spring steel or high-strength aluminum alloy and is connected by eight thin-walled flexible hinges to form an asymmetrical parallelogram structure. The main output direction of the piezoelectric stack (2) is in a straight line with the rotation center of the rotor (1), so that the greater stiffness of the piezoelectric stack (2) in the main output direction is fully utilized; the asymmetric thin-walled flexible hinge mechanism (5) has good stiffness output performance, and its upper end can withstand a greater preload force, and the movement is stable and efficient. The piezoelectric stack (2) is energized to transmit the driving force of the rotational movement of the rotor (1) and the preload force of the contact surface between the asymmetric thin-walled flexible hinge mechanism (5) and the rotor (1) through the asymmetric thin-walled flexible hinge mechanism (5), thereby greatly improving the output load of the piezoelectric drive platform and realizing rotational stepping movement along the desired direction.

[0007] The initial pre-tightening force between the asymmetric thin-walled flexible hinge mechanism (5) and the rotor (1) is adjusted by a pre-tightening screw (4);

[0008] The piezoelectric stack (2) adopts a shape-controllable surface-type piezoelectric ceramic stack PZT, and the parasitic inertial motion drive is achieved by controlling the voltage of the piezoelectric stack (2).

[0009] The contact portion between the upper end of the asymmetric thin-walled flexible hinge mechanism (5) and the rotor (1) is an arc-shaped structure, which is beneficial to the stability of the contact.

[0010] The main advantages of the present invention are: by utilizing the principle of parasitic inertial motion, the main output direction of the piezoelectric stack is aligned with the center of rotation of the rotor, and the parasitic inertial motion of the asymmetric thin-walled flexible hinge mechanism is used to transfer the load, which greatly increases the output load of the drive platform and realizes the rotational motion of the rotor. It has the advantages of high drive reliability, good stability, and high working efficiency. It 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

[0011] The illustrations of the drawings herein are used to provide further understanding of the present invention and constitute a part of this application. The illustrative examples of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0012] Figure 1 is an isometric schematic view of the present invention;

[0013] Figure 2 It is a front view schematic diagram of the present invention;

[0014] Figure 3 It is a left side schematic diagram of the present invention;

[0015] Figure 4 It is a schematic diagram of the asymmetric thin-walled flexible hinge mechanism of the present invention.

[0016] In the figure:

[0017] 1. Rotor; 2. Piezoelectric stack; 3. Preload wedge;

[0018] 4. Pre-tightening screws; 5. Asymmetric thin-walled flexible hinge mechanism; 6. 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 4As shown, a piezoelectric rotary precision drive platform based on the parasitic inertia principle mainly comprises a rotor (1), a piezoelectric stack (2), a pre-tightening wedge (3), a pre-tightening screw (4), an asymmetric thin-walled flexible hinge mechanism (5) and a base (6). The rotor (1) comprises a rotating table, a bearing and a rotating shaft, wherein 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 are in interference fit; the structure of the rotor (1) uses a high-precision bearing to reduce its friction loss, and the bearing is connected to the base through the rotating shaft; the asymmetric thin-walled flexible hinge mechanism (5) is installed on the base through screws; the piezoelectric stack (2) is installed in the asymmetric thin-walled flexible hinge mechanism (5), and its main output direction is in a straight line with the rotation center of the rotor (1); the pre-tightening wedge (3) is arranged between the piezoelectric stack (2) and the asymmetric thin-walled flexible hinge mechanism (5), and can be pre-tightened by the pre-tightening wedge (3); the pre-tightening screw (4) is fastened to the base (6) and contacts the lower end of the asymmetric thin-walled hinge; the asymmetric thin-walled flexible hinge mechanism (5) is an asymmetric thin-walled structure, and its upper arc structure contacts the rotor (1); the base (6) plays the role of supporting and installing other parts.

[0021] The main output direction of the piezoelectric stack (2) is in a straight line with the rotation center of the rotor (1), so that the larger stiffness of the piezoelectric stack (2) in the main output direction is fully utilized; the asymmetric thin-walled flexible hinge mechanism (5) has good stiffness output performance, the upper end of the asymmetric thin-walled flexible hinge mechanism (5) can withstand a larger preload force, and the movement is stable and efficient. The piezoelectric stack (2) is energized to transmit the driving force of the rotational movement of the rotor (1) and the preload force between the asymmetric thin-walled flexible hinge mechanism (5) and the rotor (1) through the asymmetric thin-walled flexible hinge mechanism (5), thereby greatly improving the output load of the piezoelectric drive platform and realizing rotational stepping movement along a certain direction.

[0022] The initial pre-tightening force between the asymmetric thin-walled flexible hinge mechanism (5) and the rotor (1) is adjusted by a pre-tightening screw (4);

[0023] The piezoelectric stack (2) adopts a piezoelectric ceramic stack PZT with a controllable surface shape, and the parasitic inertial motion is achieved by controlling the voltage of the piezoelectric stack (2).

[0024] The contact portion between the upper end of the asymmetric thin-walled flexible hinge mechanism (5) and the rotor (1) is an arc-shaped structure, which is beneficial to the stability of the contact.

[0025] See also Figures 1 to 4 As shown, the specific working process of the present invention is as follows:

[0026] The realization of the step-by-step rotational motion of the rotor, in the initial state: the pre-tightening screw (4) is adjusted to adjust the contact distance between the asymmetric thin-walled flexible hinge mechanism (5) and the rotor (1), that is, the initial pre-tightening force during the parasitic motion process. The piezoelectric stack (2) is controlled by a piezoelectric signal in the form of a sawtooth wave or a triangle wave. The piezoelectric stack (2) is not charged, and the system is in a free state; when the piezoelectric stack (2) is energized, it stretches through the inverse piezoelectric effect, pushing the asymmetric thin-walled flexible hinge mechanism (5) to deform, the asymmetric thin-walled flexible hinge mechanism (5) presses the rotor (1), and the asymmetric thin-walled flexible hinge mechanism (5) drives the rotor (1) to rotate under the action of the static friction force between the asymmetric thin-walled flexible hinge mechanism (5) and the rotor (1); when the piezoelectric stack (2) loses power and quickly retreats to the initial position, the asymmetric thin-walled flexible hinge mechanism (5) also returns to the initial state, and the rotor (1) still maintains the position after rotation under the action of the inertial force, thereby completing a motion cycle of the driving platform. By repeating the above steps, the driving platform can realize step-by-step rotational motion in a desired direction and obtain a larger output rotation angle.

[0027] The present invention relates to a piezoelectric rotary precision driving platform based on the parasitic inertia principle. Since a piezoelectric stack is used as a driving source and an asymmetric thin-walled flexible hinge mechanism is used as a power transmission element, the platform has the characteristics of low heat generation, stable, reliable and efficient driving, and can realize step-by-step rotary precision motion.

Claims

1. A piezoelectric rotary precision drive platform based on the parasitic inertia principle, comprising a rotor (1), a piezoelectric stack (2), a preload wedge (3), a preload screw (4), an asymmetric thin-walled flexible hinge mechanism (5) and a base (6), characterized in that: The precision drive platform realizes rotational motion by using the parasitic inertia principle. The rotor (1) comprises 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 and the base are interference fit. The structure of the rotor (1) uses a high-precision bearing to reduce its friction loss. The bearing is connected to the base through the rotating shaft to realize high-precision rotational motion. The asymmetric thin-walled flexible hinge mechanism (5) is installed on the base through screws. The piezoelectric stack (2) is installed in the asymmetric thin-walled flexible hinge mechanism (5) and can be pre-tightened by a pre-tightening wedge (3). The pre-tightening screw (4) can adjust the initial pre-tightening force between the asymmetric thin-walled flexible hinge mechanism (5) and the rotor (1). The asymmetric thin-walled flexible hinge mechanism (5) is made of spring steel or high-strength aluminum alloy and is connected by eight thin-walled flexible hinges to form an asymmetric parallelogram structure. The main output direction of the piezoelectric stack (2) is in a straight line with the rotation center of the rotor (1).

2. The piezoelectric rotary precision drive platform based on the parasitic inertia principle according to claim 1 is characterized in that By adopting the parasitic inertia driving principle of the asymmetric thin-walled flexible hinge mechanism (5), a single piezoelectric stack (2) is electrically driven to drive the asymmetric thin-walled flexible hinge mechanism (5) to generate a composite force in two directions, wherein the force in one direction acts as a driving force to drive the rotor (1) to perform rotational motion; and the force in the other direction presses the rotor (1) 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 The designed asymmetric thin-walled flexible hinge mechanism (5) and the pressing part of the rotor (1) are arc-shaped structures.

4. The piezoelectric rotary precision drive platform based on the parasitic inertia principle according to claim 1 is characterized in that A piezoelectric signal in the form of a sawtooth wave or a triangular wave is used to control the piezoelectric stack (2), so that the piezoelectric stack (2) slowly extends, pushing the asymmetric thin-walled flexible hinge mechanism (5) to perform parasitic inertial motion, thereby realizing the rotation of the rotor (1); when the piezoelectric stack (2) quickly retreats under the control of the piezoelectric signal, the rotor (1) maintains the angle after rotation under the action of inertia.

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