CN111245290A - Single-degree-of-freedom piezoelectric turntable and excitation method thereof - Google Patents

Abstract

The invention provides a single-degree-of-freedom piezoelectric turntable and an excitation method thereof, and belongs to the technical field of piezoelectric driving. The single-degree-of-freedom piezoelectric turntable comprises an annular base, N two-dimensional piezoelectric actuators, a disc rotor, 2N axial fixing screws, N axial pressing blocks and N radial fastening screws, wherein N is an even number which is more than or equal to 6; the time sequence and the amplitude of a path of excitation voltage signal applied to N two-dimensional piezoelectric actuators are controlled by designing, the N two-dimensional piezoelectric actuators are excited to generate bending motion along the tangential direction of the outer edge of the disc rotor, and the disc rotor is driven by friction force to realize single-degree-of-freedom rotation; and the friction force between the two-dimensional piezoelectric actuator and the disk rotor is controlled by adjusting the amplitude of the other path of voltage signal applied to the two-dimensional piezoelectric actuator. The single-degree-of-freedom piezoelectric turntable has the advantages of no support, controllable friction force, large stroke and high motion resolution, and has wide application prospect in the fields of precision driving and positioning.

Description

A single-degree-of-freedom piezoelectric turntable and its excitation method

technical field

The invention belongs to the technical field of piezoelectric driving, and in particular relates to a single-degree-of-freedom piezoelectric turntable and an excitation method thereof.

Background technique

Piezoelectric drive technology refers to a precision drive technology that uses the inverse piezoelectric effect of piezoelectric materials to convert electrical energy into mechanical energy and realizes the motion output of piezoelectric devices through a specific actuation principle. This technology has high motion accuracy and anti-electromagnetic interference. , fast response, power off self-locking and other advantages. In recent years, with the rapid development in the fields of biomedicine, optical engineering, and precision machining, they have put forward urgent demands for precision rotary motion platforms. In view of the remarkable advantages of high displacement resolution, large stroke, simple structure, self-locking after power failure, and no electromagnetic interference, the precision rotary motion platform using piezoelectric drive technology has broad application prospects in the field of precision drive and positioning. Many scholars at home and abroad have carried out extensive research on the precision piezoelectric rotary motion platform.

According to different working principles, the current piezoelectric rotary motion platform mainly includes two types: resonant type and non-resonant type. The resonant piezoelectric rotary motion platform uses the excitation voltage signal of ultrasonic frequency to excite the stator to generate ultrasonic vibration, and then drives the mover through frictional coupling to realize the output of rotary motion; it has the ability to output large stroke, high speed and large torque, but such pressure The electric rotary motion platform works in a high frequency state, and its operation is accompanied by serious friction, wear and heat problems, and the motion accuracy is low, usually only in the order of microns. The non-resonant piezoelectric rotary motion platform mainly uses the alternating change of dynamic and static friction between the mover and the stator to realize the motion output, and its operating frequency is low; although the output speed and torque of such a piezoelectric rotary platform are lower than those of the resonant type. Piezoelectric rotary motion platform, but it achieves higher motion resolution and positioning accuracy; because this type of piezoelectric rotary platform works in the low frequency range, the friction and wear problem is weakened, and the heating problem caused by high-speed and high-frequency operation is avoided; in short , the non-resonant piezoelectric rotary motion platform is more suitable for the application requirements of high motion accuracy, good stability and intermittent operation, and has gradually become a research hotspot. For the above piezoelectric rotary motion platform, the support method of the mover and the friction force between the mover and the stator are the two key factors that determine its motion output characteristics; in order to support the mover and limit its redundant motion freedom, The existing piezoelectric rotary motion platform usually needs to design a support structure to support the mover; in order to ensure the friction force required for the work between the mover and the stator, it is often necessary to configure a complex preloading mechanism to adjust the mover and stator. The pre-tightening force between the two can further adjust the friction between the two, so as to ensure that the stator can stably drive the mover to achieve motion output; however, the pre-tightening mechanism is usually a fixed mechanical device, and it is difficult to adjust the pre-tightening force during operation. And then control the size of the friction force.

SUMMARY OF THE INVENTION

In view of this, the present invention aims to provide a single-degree-of-freedom piezoelectric turntable and an excitation method thereof to solve the problems of complex supporting and limiting structures of existing single-degree-of-freedom piezoelectric drive devices, and difficulty in controlling friction during operation.

In order to achieve the above object, the technical scheme of the present invention is achieved in this way:

A single-degree-of-freedom piezoelectric turntable includes an annular base, N two-dimensional piezoelectric actuators, a disc mover, 2N axial fixing screws, N axial compression blocks, and N radial Set screws, where N is an even number greater than or equal to 6; N two-dimensional piezoelectric actuators are divided into upper and lower layers and are evenly distributed on the circumference of the annular base, and the upper and lower layers each include N/2 two-dimensional piezoelectric actuators. three-dimensional piezoelectric actuator; the structure of the N two-dimensional piezoelectric actuators is the same; each of the two-dimensional piezoelectric actuators includes a rectangular base, a piezoelectric element and a driving foot, the rectangular base, the pressure The electric element and the driving foot are fixedly connected in sequence; N rectangular gaps and N annular gaps are evenly distributed along the circumferential directions of the upper and lower end faces of the annular base respectively, and the rectangular gaps and N annular gaps on each end surface of the annular base The annular gaps are arranged in a one-to-one correspondence, wherein the annular gap is formed by removing part of the annular body from the corresponding end face of the annular base, the rectangular gap is located on the bottom surface of the annular gap, and two axial threads are arranged on the bottom surface of each annular gap hole; on the outer cylindrical surface of the annular base and in the radial direction through the center of each rectangular gap, there is a radially tightening threaded hole; the annular gap, rectangular gap, axial threaded hole and diameter of the upper end face are The annular notch, the rectangular notch, the axial threaded hole and the radially threaded hole on the lower end face are arranged in a mirror image relationship with the axially symmetric plane of the annular base as the center; the annular notch and the shaft It is adapted to the structure of the compression block, and the axial compression block is embedded in the annular gap, and is fixedly connected with the annular base through the axial fixing screw; the rectangular base of the two-dimensional piezoelectric actuator is connected to the rectangular base on the annular base. The shape and characteristics of the gap are the same, and the rectangular base is embedded in the rectangular gap; the radial set screw is connected to the annular base through the radial set screw hole, and is in contact with the rectangular base of the two-dimensional piezoelectric actuator. To the position of the set screw, the fine-tuning of the radial distribution position of the two-dimensional piezoelectric actuator along the annular base is realized; the outer edge of the disc mover is provided with an upper conical annular surface and a lower conical annular surface, and the upper layer N The driving feet of /2 two-dimensional piezoelectric actuators are in contact with the upper conical torus of the disc mover, while the driving feet of the lower N/2 two-dimensional piezoelectric actuators are in contact with the lower cone of the disc mover. The torus faces are in contact.

Further, the disc mover is supported by N two-dimensional piezoelectric actuators evenly arranged on the annular base, and the disc is restricted by the contact between the N two-dimensional piezoelectric actuators and the disc mover. The mover has all the degrees of freedom of movement except the rotational movement around its own axis.

Further, by using one voltage signal, the magnitude of the positive pressure between the two-dimensional piezoelectric actuator and the disc mover is controlled by controlling the bending motion of the N two-dimensional bending actuators along the axis of the disc mover, and further. Control the friction between the 2D piezoelectric actuator and the disc mover.

Further, each 2D piezoelectric actuator produces independent bending motions along two orthogonal directions.

Further, the annular base is machined with threaded holes, countersunk holes or through holes for fixedly connecting the single-degree-of-freedom piezoelectric turntable with other components.

An excitation method for a single-degree-of-freedom piezoelectric turntable, which is used to excite N two-dimensional piezoelectric actuators to achieve simultaneous bending motion along the outer circumference of a disc mover, and drive the disc mover to achieve single freedom Rotational motion; that is, the disc mover is driven to achieve counterclockwise or clockwise rotational motion around the Z-axis;

Among them, the specific process of driving the disc mover to rotate counterclockwise around the Z axis is as follows:

Step 1. Apply a slowly decreasing excitation voltage signal to the piezoelectric elements of the N two-dimensional piezoelectric actuators, and the N two-dimensional piezoelectric actuators generate slow bending along the counterclockwise tangent direction around the Z axis Deformed to the negative limit position, the driving feet of the N two-dimensional piezoelectric actuators generate a slow and tiny displacement along the counterclockwise tangent direction around the Z axis, and the disc mover is driven counterclockwise around the Z axis by the static friction force. small angular displacement;

Step 2: Apply a rapidly rising excitation voltage signal to the piezoelectric elements of the N two-dimensional piezoelectric actuators, and the N two-dimensional piezoelectric actuators generate rapid bending along the clockwise tangential direction around the Z axis When deformed to the positive limit position, the driving feet of the N two-dimensional piezoelectric actuators generate rapid and small displacements along the clockwise tangential direction around the Z-axis, and the disc mover remains stationary due to inertia;

Step 3. Repeat steps 1 to 2 to realize the continuous rotation of the disc mover in the counterclockwise direction around the Z axis;

The specific process of driving the disc mover to rotate clockwise around the Z axis is as follows:

Step 1. Apply a slowly rising excitation voltage signal to the piezoelectric elements of the N two-dimensional piezoelectric actuators, and the N two-dimensional piezoelectric actuators generate slow bending along the clockwise tangential direction around the Z axis Deformed to the positive limit position, the driving feet of the N two-dimensional piezoelectric actuators generate a slow and tiny displacement along the clockwise tangent direction around the Z axis, and the disc mover is driven clockwise around the Z axis by the static friction force. small angular displacement;

Step 2: Apply a rapidly decreasing excitation voltage signal to the piezoelectric elements of the N two-dimensional piezoelectric actuators, and the N two-dimensional piezoelectric actuators generate rapid bending along the counterclockwise tangent direction around the Z axis When deformed to the negative limit position, the driving feet of N two-dimensional piezoelectric actuators generate rapid and small displacement along the counterclockwise tangent direction around the Z axis, and the disc mover remains stationary due to inertia;

Step 3: Repeat steps 1 to 2 to realize the continuous rotational movement of the disc mover in the clockwise direction around the Z axis.

Further, the excitation voltage signal required to realize the method is a periodic, asymmetric sawtooth or trapezoidal waveform, and the rise and fall process of the excitation voltage signal in each cycle can be linear or nonlinear, but the rise and fall of the excitation voltage signal can be linear or non-linear. and the duration of the descending process is not equal.

Compared with the prior art, the single-degree-of-freedom piezoelectric turntable and the excitation method thereof of the present invention have the following advantages:

The single-degree-of-freedom rotational motion output of the disc mover can be realized; among them, the disc mover has a large stroke and high-resolution motion output capability; the double-layer configuration of the two-dimensional piezoelectric actuator in the single-degree-of-freedom piezoelectric rotary table , and the special outer structure design of the disc mover, on the one hand, the self-support and limit of the disc mover is realized without adding other auxiliary devices, and on the other hand, the two-dimensional piezoelectric actuator and the circular disc mover are realized during operation. The adjustment of the positive pressure between the plate movers and the adjustment of the friction force between them is realized; the single-degree-of-freedom piezoelectric rotary table disclosed in the present invention overcomes the complex preload structure of the traditional piezoelectric rotary table and the difficulty in regulating the friction force. Disadvantages: The electrical regulation of the friction force between the two-dimensional piezoelectric actuator and the disc mover is realized through electrical signals, which is expected to improve its mechanical output performance and expand its application in ultra-precision rotary drive and positioning.

Description of drawings

The accompanying drawings constituting a part of the present invention are used to provide further understanding of the present invention, and the exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the attached image:

Figure 1 is a three-dimensional schematic diagram of a single-degree-of-freedom piezoelectric turntable when N is equal to 6;

Figure 2 is an exploded view of a single two-dimensional piezoelectric actuator tightening structure of a single-degree-of-freedom piezoelectric turntable when N is equal to 6;

Figure 3 is a schematic diagram of a single two-dimensional piezoelectric actuator making forward and reverse bending motions along two orthogonal directions A1 and A2 respectively; wherein, sub-figure (a) represents a single two-dimensional piezoelectric actuator along the A2 direction Positive bending motion, part (b) represents the negative bending motion of a single 2D piezoelectric actuator along the A2 direction, part (c) represents the positive bending motion of a single 2D piezoelectric actuator along the A1 direction, part Figure (d) shows the negative bending motion of a single 2D piezoelectric actuator along the A1 direction;

4 is a schematic diagram of the motion of a single-degree-of-freedom piezoelectric turntable in which a two-dimensional piezoelectric actuator bends slowly from a positive limit position to a negative limit position at the same time;

5 is a schematic diagram of the motion of a single-degree-of-freedom piezoelectric turntable in which a two-dimensional piezoelectric actuator bends rapidly from a negative limit position to a positive limit position at the same time;

6 is a schematic diagram of the motion of a single-degree-of-freedom piezoelectric turntable in which a two-dimensional piezoelectric actuator bends slowly from a negative limit position to a positive limit position at the same time;

7 is a schematic diagram of the motion of a single-degree-of-freedom piezoelectric turntable in which a two-dimensional piezoelectric actuator bends rapidly from a positive limit position to a negative limit position at the same time;

Figure 8 is a schematic diagram of the excitation voltage signal of the single-degree-of-freedom piezoelectric rotary table; wherein, V _max is the maximum value of the positive voltage amplitude, -V _max is the maximum value of the negative voltage amplitude, T is the period, and t is the The duration of the slow change of the voltage signal in one cycle, t exceeds the half cycle T/2; sub-picture (a) shows that in a cycle T, the excitation voltage signal whose amplitude decreases from the positive maximum value to the negative maximum value is applied first, and the sub-picture ( b) Indicates that an excitation voltage signal whose amplitude rises from a negative maximum value to a positive maximum value is firstly applied in a period T;

FIG. 9 is a schematic diagram of realizing the adjustment of the preload force of the single-degree-of-freedom piezoelectric rotary table, wherein the dashed arrows indicate the bending motion directions of the corresponding two-dimensional piezoelectric actuators.

In the above drawings, the coordinate system XYZ is a Cartesian space Cartesian coordinate system, and the Z axis coincides with the axis of the disc mover, and the X and Y axes respectively represent two orthogonal directions on the axial symmetry plane of the disc mover. .

Detailed ways

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the protection scope of the present invention.

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

Embodiment 1: This embodiment will be further described in detail with reference to Fig. 1 and Fig. 2 of the specification. This embodiment provides a specific implementation of a single-degree-of-freedom piezoelectric turntable, a single-degree-of-freedom piezoelectric turntable, comprising an annular base 1, N two-dimensional piezoelectric actuators 2, and a disc mover 3. 2N axial set screws 4, N axial compression blocks 5, N radial set screws 6, where N is an even number greater than or equal to 6; N two-dimensional piezoelectric actuators 2 are divided into The upper and lower layers are evenly distributed on the circumference of the annular base 1, and the upper and lower layers each include N/2 two-dimensional piezoelectric actuators 2; the N two-dimensional piezoelectric actuators 2 have the same structure; Each of the two-dimensional piezoelectric actuators 2 includes a rectangular base 2-1, a piezoelectric element 2-2 and a driving foot 2-3, a rectangular base 2-1, a piezoelectric element 2-2 and a driving foot 2 -3 Fixed connection in sequence; N rectangular gaps 1-1 and N annular gaps 1-2 are evenly distributed along the circumferential direction of the upper and lower end faces of the annular base 1, and each end face of the annular base 1 The rectangular notch 1-1 and the annular notch 1-2 are set in one-to-one correspondence, wherein the annular notch 1-2 is formed after removing part of the annular body from the corresponding end face of the annular base 1, and the rectangular notch 1-1 is located in the annular notch 1 -2 on the bottom surface of each annular gap 1-2 are provided with 2 axial threaded holes 1-3; on the outer cylindrical surface of the annular base 1 and through the center of each rectangular gap 1-1 In the upward direction, there is a radially tightening threaded hole 1-4; the annular gap 1-2, the rectangular gap 1-1, the axial threaded hole 1-3 and the radially tightening threaded hole 1- 4 and the annular gap 1-2, the rectangular gap 1-1, the axial threaded hole 1-3 and the radial tightening threaded hole 1-4 on the lower end face are mirror images with the axial symmetry plane of the annular base 1 as the center The relationship is arranged; the annular gap 1-2 is adapted to the structure of the axial compression block 5, and the axial compression block 5 is embedded in the annular gap 1-2, and is fixedly connected to the annular base 1 through the axial fixing screw 4 ; The rectangular base 2-1 of the two-dimensional piezoelectric actuator 2 has the same shape and characteristics as the rectangular gap 1-1 on the annular base 1, and the rectangular base 2-1 is embedded in the rectangular gap 1-1; The screw 6 is connected to the annular base 1 through the radially tightening threaded holes 1-4, and is in contact with the rectangular base 2-1 of the two-dimensional piezoelectric actuator 2. By adjusting the position of the radially tightening screw 6, Realize the fine-tuning of the radial distribution position of the two-dimensional piezoelectric actuator 2 along the annular base 1; the outer edge of the disc mover 3 is provided with an upper conical annulus 3-1 and a lower conical annulus 3-2, The driving feet 2-3 of the N/2 two-dimensional piezoelectric actuators 2 in the upper layer are in contact with the upper conical torus 3-1 of the disc mover 3, and the N/2 two-dimensional piezoelectric actuators in the lower layer are in contact with each other. The driving foot 2-3 of 2 is in contact with the lower conical annular surface 3-2 of the disc mover 3; The degree of freedom piezoelectric turntable is connected to other components.

Specific embodiment 2: This embodiment will be further described in detail with reference to FIG. 3 in the description. This embodiment provides a specific embodiment in which a single two-dimensional piezoelectric actuator 2 realizes bending motion along two orthogonal directions of A1 and A2. The two-dimensional bending motion that can be realized by a single two-dimensional piezoelectric actuator 2 is shown in Figure 3. By applying an excitation voltage signal to the piezoelectric element 2-2, the positive and negative bending along the A2 axis direction can be realized Motion: When the amplitude of the excitation voltage signal is positive, the two-dimensional piezoelectric actuator 2 produces a bending motion along the positive axis of A2, as shown in Figure 3(a); when the amplitude of the excitation voltage signal is negative , the two-dimensional piezoelectric actuator 2 produces a bending motion along the negative direction of the A2 axis, as shown in Fig. 3(b). By applying another excitation voltage signal to the piezoelectric element 2-2 respectively, the positive and negative bending motions along the A1 axis can be realized. When the amplitude of the excitation voltage signal is positive, the two-dimensional piezoelectric actuator 2 produces a positive bending motion along the A1 axis, as shown in Figure 3(c); when the amplitude of the excitation voltage signal is negative, the two-dimensional piezoelectric actuator 2 produces a negative bending motion along the A1 axis, as shown in Figure 3(d). The above-mentioned A1 and A2 axis directions only represent two orthogonal bending motion directions realized by the two-dimensional piezoelectric actuator 2 .

Embodiment 3: This embodiment will be further described in detail with reference to FIGS. 4 to 8 of the specification. This embodiment provides a specific embodiment of the excitation method of the single-degree-of-freedom piezoelectric turntable. The Cartesian Cartesian coordinate system XYZ is established with the center of the disk mover 3 as the coordinate origin, and the Z axis of the coordinate system is related to the disk mover 3. If the axes are collinear, the excitation method can excite the disc mover 3 of the single-degree-of-freedom piezoelectric turntable to achieve counterclockwise or clockwise rotation output around the Z axis; the following description is the two-dimensional piezoelectric actuator 2 The number N is equal to six cases.

The specific process of driving the disc mover 3 to rotate counterclockwise around the Z axis is as follows:

Step 1. Apply a slowly decreasing excitation voltage signal on the piezoelectric elements 2-2 of the six two-dimensional piezoelectric actuators 2, corresponding to the t period in an excitation voltage signal period T in FIG. 8(a); six The six two-dimensional piezoelectric actuators 2 are slowly bent and deformed to the negative limit along the counterclockwise tangential direction around the Z-axis, and the driving feet 2-3 of the six two-dimensional piezoelectric actuators 2 are along the A slow and small displacement is generated in the counterclockwise tangential direction of the Z-axis, and the disc mover 3 is driven by the static friction force to generate a small angular displacement around the Z-axis in the counterclockwise direction, as shown in Figure 4;

Step 2: Apply a fast-rising excitation voltage signal on the piezoelectric elements 2-2 of the six two-dimensional piezoelectric actuators 2, corresponding to the T-t period in an excitation voltage signal period T in FIG. 8(a); six The two two-dimensional piezoelectric actuators 2 are rapidly bent and deformed to the positive limit along the clockwise tangential direction around the Z-axis, and the driving feet 2-3 of the six two-dimensional piezoelectric actuators 2 are along the A small and rapid displacement occurs in the clockwise tangential direction of the Z axis, and the disc mover 3 remains stationary due to inertia, as shown in Figure 5;

In the above steps 1 and 2, the duration of the t period is greater than half the excitation period T/2 of the excitation voltage signal;

Step 3: Repeat steps 1 to 2, that is, repeatedly apply the excitation voltage signals of multiple cycles shown in FIG. 8(a) to the six two-dimensional piezoelectric actuators to realize the counterclockwise direction of the disc mover 3 around the Z axis. The continuous rotation motion output of ;

The specific process of driving the disc mover 3 to rotate clockwise around the Z axis is as follows:

Step 1. Apply a slow-rising excitation voltage signal on the piezoelectric elements 2-2 of the six two-dimensional piezoelectric actuators 2, corresponding to the t period in an excitation voltage signal period T in FIG. 8(b); six The two two-dimensional piezoelectric actuators 2 are slowly bent and deformed to the positive limit along the clockwise tangential direction around the Z-axis, and the driving feet 2-3 of the six two-dimensional piezoelectric actuators 2 are along the A slow and small displacement is generated in the clockwise tangential direction of the Z axis, and the disc mover 3 is driven by the static friction force to generate a small angular displacement in the clockwise direction of the Z axis, as shown in Figure 6;

Step 2. Apply a fast-dropping excitation voltage signal on the piezoelectric elements 2-2 of the six two-dimensional piezoelectric actuators 2, corresponding to the T-t period in an excitation voltage signal period T in FIG. 8(a); six The two two-dimensional piezoelectric actuators 2 are rapidly bent and deformed to the negative limit position along the counterclockwise tangential direction around the Z-axis, and the driving feet 2-3 of the six two-dimensional piezoelectric actuators 2 are along the A rapid and small displacement occurs in the counterclockwise tangential direction of the Z axis, and the disc mover 3 remains stationary due to inertia, as shown in Figure 7;

In the above steps 1 and 2, the duration of the t period is greater than half the excitation period T/2 of the excitation voltage signal;

Step 3: Repeat steps 1 to 2, that is, repeatedly apply the excitation voltage signals of multiple cycles shown in FIG. 8(b) to the six two-dimensional piezoelectric actuators to realize the clockwise direction of the disc mover 3 around the Z axis. of continuous rotational motion output.

Embodiment 4: This embodiment will be further described in detail with reference to FIG. 9 in the description. This embodiment provides a specific embodiment of adjusting the preload force of the single-degree-of-freedom piezoelectric turntable by using a voltage signal, thereby regulating the friction force; The preload force of the single-degree-of-freedom piezoelectric turntable refers to the positive pressure between the six two-dimensional piezoelectric actuators 2 of the single-degree-of-freedom piezoelectric turntable and the disc mover 3; the positive pressure determines the two-dimensional piezoelectric The size of the sliding friction between the actuator 2 and the disc mover 3, the sliding friction between the two-dimensional piezoelectric actuator 2 and the disc mover 3 is proportional to the positive pressure between them; The voltage signals with positive and negative amplitudes are respectively applied to three two-dimensional piezoelectric actuators 2 in the upper layer, three two-dimensional piezoelectric actuators 2 in the lower layer, and three two-dimensional piezoelectric actuators in the upper layer of the single-degree-of-freedom piezoelectric turntable. The piezoelectric actuator 2 produces a bending motion along the negative Z axis, while the lower three two-dimensional piezoelectric actuators 2 generate a bending motion along the positive Z axis, and the two-dimensional piezoelectric actuators 2 bend along the Z axis. The direction of movement is shown by the dashed arrow in Figure 9; since the two-dimensional piezoelectric actuator 2 belongs to an elastic body, the upper and lower two-dimensional piezoelectric actuators 2 generate slight amplitudes along the negative Z-axis and the positive Z-axis, respectively During the bending motion, the driving foot 2-3 of the two-dimensional piezoelectric actuator 2 is always in contact with the upper conical annulus 3-1 and the lower conical annulus 3-2 of the disc mover 3; by increasing and decreasing The magnitude of the voltage signal used can realize the increase and decrease of the positive pressure between the six two-dimensional piezoelectric actuators 2 and the disc mover 3; due to the six two-dimensional piezoelectric actuators 2 and the disc The frictional force between the movers 3 is proportional to the positive pressure, so that the magnitude of the frictional force can be adjusted by using the voltage signal.

The invention proposes a piezoelectric turntable with a single degree of freedom. By designing the configuration relationship of a plurality of two-dimensional piezoelectric actuators and the structure of the disc mover, on the one hand, the unification of supporting and driving components is realized, and the use of other On the other hand, it can realize the electrical adjustment of the friction force of the piezoelectric rotary table during operation; it overcomes the complex structure of the traditional piezoelectric rotary table and the uncontrollable preload force during operation, which causes the friction between the mover and the stator. The shortcoming that the friction force is difficult to control; an excitation method of the single-degree-of-freedom piezoelectric turntable is proposed, and its multiple two-dimensional piezoelectric actuators are excited by periodic excitation signals to generate bending motion, and the driving feet form a specific direction along the The small displacement in the direction, and the use of friction to drive the mover to continue to rotate. All in all, a single-degree-of-freedom piezoelectric turntable of the present invention realizes the self-supporting and limiting of the mover, and the electrical regulation of friction during operation, and at the same time has the characteristics of large stroke, no heat, and high motion resolution. Support its application in ultra-precision drive and positioning engineering.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the scope of the present invention. within the scope of protection.

Claims (7)

1. A single degree of freedom piezoelectric turntable is characterized in that: the piezoelectric actuator comprises an annular base (1), N two-dimensional piezoelectric actuators (2), a disk rotor (3), 2N axial fixing screws (4), N axial compression blocks (5) and N radial set screws (6), wherein N is an even number which is more than or equal to 6; the N two-dimensional piezoelectric actuators (2) are divided into an upper layer and a lower layer which are uniformly distributed on the circumference of the annular base (1), and the upper layer and the lower layer respectively comprise N/2 two-dimensional piezoelectric actuators (2); the N two-dimensional piezoelectric actuators (2) have the same structure; each two-dimensional piezoelectric actuator (2) comprises a rectangular base (2-1), a piezoelectric element (2-2) and a driving foot (2-3), wherein the rectangular base (2-1), the piezoelectric element (2-2) and the driving foot (2-3) are fixedly connected in sequence; n rectangular notches (1-1) and N annular notches (1-2) are respectively and uniformly distributed along the circumferential direction of the upper end face and the lower end face of the annular base (1), the rectangular notches (1-1) and the annular notches (1-2) on each end face of the annular base (1) are uniformly and correspondingly arranged, the annular notches (1-2) are formed by removing part of annular bodies from the corresponding end faces of the annular base (1), the rectangular notches (1-1) are located on the bottom faces of the annular notches (1-2), and 2 axial threaded holes (1-3) are formed in the bottom faces of the annular notches (1-2); a radial fastening threaded hole (1-4) is formed in the outer cylindrical surface of the annular base (1) in the radial direction passing through the center of each rectangular notch (1-1); the annular gap (1-2), the rectangular gap (1-1), the axial threaded hole (1-3) and the radial fastening threaded hole (1-4) on the upper end surface are arranged in a mirror image relationship with the annular gap (1-2), the rectangular gap (1-1), the axial threaded hole (1-3) and the radial fastening threaded hole (1-4) on the lower end surface by taking the axial symmetry plane of the annular base (1) as the center; the annular gap (1-2) is matched with the axial compression block (5) in structure, and the axial compression block (5) is embedded into the annular gap (1-2) and fixedly connected with the annular base (1) through an axial fixing screw (4); the rectangular base (2-1) of the two-dimensional piezoelectric actuator (2) is the same as the rectangular notch (1-1) on the annular base (1) in shape and characteristic, and the rectangular base (2-1) is embedded into the rectangular notch (1-1); the radial set screw (6) is connected with the annular base (1) through a radial set threaded hole (1-4) and is in contact with the rectangular base (2-1) of the two-dimensional piezoelectric actuator (2), and the fine adjustment of the radial distribution position of the two-dimensional piezoelectric actuator (2) along the annular base (1) is realized by adjusting the position of the radial set screw (6); the outer edge of the disc rotor (3) is provided with an upper conical ring surface (3-1) and a lower conical ring surface (3-2), the driving feet (2-3) of the upper N/2 two-dimensional piezoelectric actuators (2) are in contact with the upper conical ring surface (3-1) of the disc rotor (3), and the driving feet (2-3) of the lower N/2 two-dimensional piezoelectric actuators (2) are in contact with the lower conical ring surface (3-2) of the disc rotor (3).

2. The single degree of freedom piezoelectric turntable of claim 1, wherein: the disc rotor (3) is supported by N two-dimensional piezoelectric actuators (2) uniformly arranged on the annular base (1), and all motion freedom degrees of the disc rotor (3) except for the rotation motion around the axis of the disc rotor are limited by the contact between the N two-dimensional piezoelectric actuators (2) and the disc rotor (3).

3. The single degree of freedom piezoelectric turntable of claim 1, wherein: by means of one path of voltage signals, positive pressure between the two-dimensional piezoelectric actuator (2) and the disc rotor (3) is controlled by controlling bending motion of the N two-dimensional bending actuators (2) along the axis direction of the disc rotor (3), and friction between the two-dimensional piezoelectric actuator (2) and the disc rotor (3) is further controlled.

4. The single degree of freedom piezoelectric turntable of claim 1, wherein: each two-dimensional piezoelectric actuator (2) produces independent bending motion along two orthogonal directions.

5. The single degree of freedom piezoelectric turntable of claim 1, wherein: the annular base (1) is provided with a threaded hole, a countersunk hole or a through hole for fixedly connecting the single-degree-of-freedom piezoelectric turntable with other parts.

6. The excitation method of the single degree of freedom piezoelectric turntable as set forth in any one of claims 1 to 5, wherein: the method is used for exciting N two-dimensional piezoelectric actuators (2) to realize bending motion along the circumferential tangential direction outside a disc rotor (3) at the same time, and driving the disc rotor (3) to realize single-degree-of-freedom rotary motion; namely, the disc rotor (3) realizes the rotation motion around the Z axis in the anticlockwise or clockwise direction;

the specific process of the driving disc rotor (3) rotating around the Z axis in the anticlockwise direction is as follows:

firstly, slowly-descending excitation voltage signals are applied to piezoelectric elements (2-2) of N two-dimensional piezoelectric actuators (2), the N two-dimensional piezoelectric actuators (2) generate slow bending deformation to a negative electrode limit position along a tangential direction anticlockwise around a Z axis, driving feet (2-3) of the N two-dimensional piezoelectric actuators (2) generate slowly-changing micro displacement along the tangential direction anticlockwise around the Z axis, and the disc rotor (3) is driven by static friction force to generate micro angular displacement along the anticlockwise direction around the Z axis;

secondly, applying a rapidly rising excitation voltage signal to the piezoelectric elements (2-2) of the N two-dimensional piezoelectric actuators (2), enabling the N two-dimensional piezoelectric actuators (2) to rapidly bend and deform to a positive limit position along a clockwise tangential direction around the Z axis, enabling the driving feet (2-3) of the N two-dimensional piezoelectric actuators (2) to rapidly change micro displacement along the clockwise tangential direction around the Z axis, and enabling the disc rotor (3) to keep static due to inertia;

step three, repeating the step one to the step two to realize the continuous rotary motion of the disc rotor (3) around the Z axis in the anticlockwise direction;

the specific process of the clockwise rotary motion of the driving disc rotor (3) around the Z axis is as follows:

firstly, applying slowly rising excitation voltage signals to piezoelectric elements (2-2) of N two-dimensional piezoelectric actuators (2), enabling the N two-dimensional piezoelectric actuators (2) to generate slow bending deformation to a positive limit position along a clockwise tangential direction around a Z axis, enabling driving feet (2-3) of the N two-dimensional piezoelectric actuators (2) to generate slowly changing micro displacement along the clockwise tangential direction around the Z axis, and driving a disc rotor (3) to generate micro angular displacement along the clockwise direction around the Z axis through static friction force;

secondly, applying a rapidly-descending excitation voltage signal to the piezoelectric elements (2-2) of the N two-dimensional piezoelectric actuators (2), enabling the N two-dimensional piezoelectric actuators (2) to rapidly bend and deform to a negative limit position along a tangential direction anticlockwise around the Z axis, enabling the driving feet (2-3) of the N two-dimensional piezoelectric actuators (2) to rapidly change micro displacement along the tangential direction anticlockwise around the Z axis, and enabling the disc rotor (3) to keep static due to inertia;

and step three, repeating the step one to the step two to realize the continuous rotation motion of the disc rotor (3) around the Z axis in the clockwise direction.

7. The excitation method of the single-degree-of-freedom piezoelectric turntable as claimed in claim 6, wherein: the excitation voltage signal required for realizing the method is a periodic, asymmetric sawtooth or trapezoidal waveform, the rising and falling processes of the excitation voltage signal in each period can be linear or nonlinear, but the duration of the rising and falling processes is not equal.

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