CN102843063A - Screw-thread-driven rotary-linear ultrasonic motor using columnar stator high-order bending vibration mode - Google Patents

Abstract

The invention relates to a thread-driven rotary linear ultrasonic motor utilizing a high-order bending vibration mode of a columnar stator, belonging to the technical field of ultrasonic motors. It solves the problem of small output torque when the thread-driven rotary-linear ultrasonic motor in the bending vibration mode of the columnar stator is miniaturized. It includes a threaded output shaft, a metal tube elastic sleeve and m groups of piezoelectric ceramic sheets, or includes a threaded output shaft, piezoelectric ceramic tubes, two metal caps and p groups of external electrodes. Orthogonal two high-order bending vibrations, such as second-order or third-order bending vibration modes, are generated on the inner surface of the stator driving end composed of metal tube elastic sleeves and m groups of piezoelectric ceramic sheets by using the superposition and coupling of vibrations Driving the traveling wave, the stator and the threaded output shaft are driven by the threaded pair, and under the action of the axial load force, the output shaft's rotation-linear motion output is realized. The invention is used as a rotary linear ultrasonic motor.

Description

Thread-driven rotary linear ultrasonic motor utilizing high-order bending vibration modes of cylindrical stator

technical field

The invention relates to a thread-driven rotary linear ultrasonic motor utilizing the high-order bending vibration mode of a columnar stator, and belongs to the technical field of ultrasonic motors.

Background technique

The thread-driven rotary-linear ultrasonic motor using the bending vibration mode of the cylindrical stator is one of many types of ultrasonic motors. Compared with other types of ultrasonic motors, the stator and output shaft of this type of ultrasonic motor are The two spatially orthogonal bending vibration modes use the coupling and superposition of vibration to generate driving traveling waves on the inner surface of the stator driving end, which can easily realize the output of the screw output shaft rotation-linear degree of freedom motion. Compared with the disc traveling wave ultrasonic motor, it has the characteristics of simple structure, easy miniaturization and high positioning accuracy.

The thread-driven ultrasonic motor based on the thread pair transmission can be divided into the following types according to the difference in the stator structure and excitation mode of the ultrasonic motor: the thread-driven polyhedral ultrasonic motor with a polyhedral structure that uses in-plane bending vibration mode coupling to drive traveling waves , using the thread-driven ultrasonic motor driven by the standing wave of the in-plane bending vibration mode of the ring-shaped ultra-thin structure stator. The stators of these two types of motors mostly adopt polyhedron or ring-shaped structures, and the motor is realized by exciting the in-plane vibration mode of the stator. Rotary-linear motion of the output part.

In order to reduce the resonant frequency of the motor stator, a threaded linear motor driven by a piezoelectric composite bending beam whose stator is fixed at one end with a cantilever beam structure is also proposed. This type of motor mainly uses the space orthogonal bending of the columnar cantilever beam structure stator The coupling of vibration modes generates driving waves to realize the motion output of the output shaft; another representative thread-driven cylindrical rotary-linear ultrasonic motor mainly includes metal tube type and piezoelectric tube type with stators pasted with piezoelectric sheets. Two types of ultrasonic waveguide screw motors, the ultrasonic waveguide screw motor mainly uses two first-order bending vibrations that are orthogonal to each other in the space of a cylindrical stator that is freely constrained at both ends to couple with each other, and generates driving traveling waves on the inner surface of the free end of the stator. The stator and the output shaft are driven by thread pairs, and the output shaft’s rotation-linear motion output is realized under the action of the axial load force; the piezoelectric elements used in the above-mentioned thread-driven ultrasonic motor stators mostly use the d ₃₁ vibration mode, which vibration mode There are certain advantages in the miniaturization of motors, especially for ultrasonic guiding screw motors, this advantage is more obvious, but at the same time there is an inevitable practical problem of small output force.

In order to increase the output force of the motor and improve the load characteristics, a class of piezoelectric sheet sandwich rotary linear ultrasonic motors using the vibration mode of the piezoelectric element d ₃₃ , and a piezoelectric thread-driven linear ultrasonic motor using the mode conversion type, and Compared with the thread-driven ultrasonic motor using piezoelectric element d ₃₁ vibration mode, this type of motor has obvious advantages in output force, but there is a problem that miniaturization is difficult.

Contents of the invention

The invention aims to solve the problem of small output torque when the thread-driven rotary-linear ultrasonic motor in the bending vibration mode of the cylindrical stator is miniaturized, and provides a thread-driven rotary linear ultrasonic motor utilizing the high-order bending vibration mode of the cylindrical stator.

First technical scheme of the present invention:

A thread-driven rotary linear ultrasonic motor utilizing the high-order bending vibration mode of a cylindrical stator, which includes a threaded output shaft, a metal tube elastic sleeve, and m groups of piezoelectric ceramic sheets, where m is a positive integer,

The metal tube elastic sleeve is sleeved on the outer surface of the threaded output shaft, and is connected with the threaded output shaft through a thread pair. The outer contour of the cross section of the metal tube elastic sleeve is a regular n-gon, and the value of n is an integer of 4 times,

On the outer surface of the elastic sleeve of the metal tube, m groups of piezoelectric ceramic sheets are evenly distributed in the axial direction, each group of piezoelectric ceramic sheets is composed of n piezoelectric ceramic sheets, and the n piezoelectric ceramic sheets of each group of piezoelectric ceramic sheets are distributed correspondingly On each plane of the outer surface of the elastic sleeve of the metal tube;

The piezoelectric ceramic sheet is polarized along the thickness direction, and the upper and lower surfaces of the piezoelectric ceramic sheet are plated with silver electrodes.

Second technical scheme of the present invention:

A thread-driven rotary linear ultrasonic motor utilizing the high-order bending vibration mode of a cylindrical stator, which includes a threaded output shaft, a metal tube elastic sleeve, and m groups of piezoelectric ceramic sheets, where m is a positive integer,

The metal tube elastic sleeve is sleeved on the outer surface of the threaded output shaft, and is connected with the threaded output shaft through a thread pair. The outer contour of the cross section of the metal tube elastic sleeve is a shape composed of a circular arc and two straight lines. Where the arc is greater than or equal to half the circumference, and the two straight line segments are equal in length and perpendicular to each other;

On the outer surface of the elastic sleeve of the metal tube, m groups of piezoelectric ceramic sheets are evenly distributed along the axial direction, each group of piezoelectric ceramic sheets is composed of two piezoelectric ceramic sheets, and the two piezoelectric ceramic sheets of each group of piezoelectric ceramic sheets are distributed correspondingly On two planes on the outer surface of the elastic sleeve of the metal tube;

The piezoelectric ceramic sheet is polarized along the thickness direction, and the upper and lower surfaces of the piezoelectric ceramic sheet are plated with silver electrodes.

In the above two technical solutions, the m groups of piezoelectric ceramic sheets are respectively located at the center amplitudes of the m amplitudes of the m-order bending vibration of the elastic sleeve of the metal tube.

The piezoelectric ceramic sheet is bonded and fixed to the outer surface of the elastic sleeve of the metal tube through epoxy resin glue.

The material of the metal tube elastic sleeve is titanium alloy, copper alloy, alloy steel or aluminum alloy;

The piezoelectric ceramic sheet is made of piezoelectric ceramic material with piezoelectric effect.

The third technical scheme of the present invention:

A thread-driven rotary linear ultrasonic motor utilizing a high-order bending vibration mode of a cylindrical stator, which includes a threaded output shaft, a piezoelectric ceramic tube, two metal caps, and p groups of external electrodes, where p is a positive integer,

The two ends of the piezoelectric ceramic tube are respectively bonded with a metal cap to form a stator. The stator is sleeved on the outside of the threaded output shaft, and the two metal caps are connected with the threaded output shaft through a thread pair.

The inner surface of the piezoelectric ceramic tube is covered with internal electrodes, and the outer surface of the piezoelectric ceramic tube is uniformly distributed in p groups of external electrodes along the axial direction. Each group of external electrodes includes q external electrodes, and the value of q is an integer multiple of 4. Each The q external electrodes in the group of external electrodes are evenly distributed and fixed along the circumferential direction of the piezoelectric ceramic tube,

The piezoelectric ceramic tube is polarized in radial direction.

The piezoelectric ceramic tube and the metal cap are bonded and fixed with epoxy resin.

The material of the metal cap is titanium alloy, copper alloy, alloy steel or aluminum alloy;

The piezoelectric ceramic tube is made of piezoelectric ceramic material with piezoelectric effect.

Among the above three technical solutions:

Both ends of the threaded output shaft are of flat head structure or ball end structure.

The material of the threaded output shaft is copper alloy, alloy steel metal or polytetrafluoroethylene high polymer material.

The advantages of the present invention are: the present invention excites two high-order bending vibrations that are orthogonal to each other in the space of the free stator, such as the second-order or third-order bending vibration modes, and utilizes the superposition and coupling of vibrations to form a metal tube elastic sleeve The inner surface of the stator driving end composed of m groups of piezoelectric ceramic sheets generates driving traveling waves, and the stator and the threaded output shaft are driven by the threaded pair, and the output shaft's rotation-linear motion output is realized under the action of the axial load force. The performance of the ultrasonic motor of the present invention is significantly improved, especially in terms of output force. While meeting miniaturization, its maximum output force can be increased by more than 50% compared with the current technology.

The invention has high working efficiency and good mechanical properties, and promotes the practical and miniaturization process of the bending vibration mode rotation-linear ultrasonic motor.

The invention has broad application prospects in the fields of aerospace, medical equipment, intelligent robots, digital products, precision drive systems and the like.

Description of drawings

Fig. 1 is a schematic structural view of the thread-driven rotary linear ultrasonic motor according to Embodiment 1 of the present invention. In the figure, there are two groups of piezoelectric ceramic sheets, and the outer contour of the cross-section of the metal tube elastic sleeve is square; the sign "+" in the figure and "-" indicate the polarization direction of the piezoelectric ceramic sheet;

Fig. 2 is a sectional view along the axial direction of Fig. 1;

Fig. 3 is a sectional view in the side view direction of Fig. 1; the arrows in the figure indicate the polarization direction of the piezoelectric ceramic sheet;

Fig. 4 is a schematic diagram of the second-order bending vibration mode of the ultrasonic motor shown in Fig. 1;

Fig. 5 is a structural schematic diagram of a thread-driven rotary linear ultrasonic motor according to Embodiment 1 of the present invention. In the figure, there are three groups of piezoelectric ceramic sheets, and the outer contour of the cross-section of the elastic sleeve of the metal tube is square;

Fig. 6 is a sectional view along the axial direction of Fig. 5;

Fig. 7 is a schematic diagram of the third-order bending vibration mode of the ultrasonic motor shown in Fig. 5;

Fig. 8 is a schematic structural diagram of the thread-driven rotary linear ultrasonic motor according to Embodiment 2 of the present invention, in which there are two groups of piezoelectric ceramic sheets;

Fig. 9 is a side view sectional view of Fig. 8;

Fig. 10 is a schematic diagram of the second-order bending vibration mode of the ultrasonic motor shown in Fig. 8;

Fig. 11 is a schematic structural diagram of the thread-driven rotary linear ultrasonic motor according to Embodiment 2 of the present invention, in which there are three groups of piezoelectric ceramic sheets;

Fig. 12 is a schematic diagram of the third-order bending vibration mode of the ultrasonic motor shown in Fig. 11;

Fig. 13 is a schematic structural diagram of the thread-driven rotary linear ultrasonic motor described in Embodiment 6 of the present invention, in which the outer electrodes are divided into two groups;

Fig. 14 is a sectional view along the axial direction of Fig. 13;

Fig. 15 is a schematic diagram of the second-order bending vibration mode of the ultrasonic motor shown in Fig. 13;

Fig. 16 is a schematic structural diagram of the thread-driven rotary linear ultrasonic motor described in Embodiment 6 of the present invention, in which there are three groups of external electrodes;

Fig. 17 is a sectional view along the axial direction of Fig. 16;

FIG. 18 is a schematic diagram of the third-order bending vibration mode of the ultrasonic motor shown in FIG. 16 .

Detailed ways

Specific Embodiment 1: The present embodiment will be described below with reference to FIGS. 1 to 7. The thread-driven rotary linear ultrasonic motor using the high-order bending vibration mode of the columnar stator described in this embodiment includes a threaded output shaft 1, a metal tube elastic Sleeve 2 and m groups of piezoelectric ceramic sheets 3, m is a positive integer,

The metal tube elastic sleeve 2 is sleeved on the outer surface of the threaded output shaft 1, and is connected with the threaded output shaft 1 through a thread pair. The outer contour of the cross section of the metal tube elastic sleeve 2 is a regular n-gon, and the value of n is is an integer multiple of 4,

On the outer surface of the metal tube elastic sleeve 2, m groups of piezoelectric ceramic sheets 3 are evenly distributed in the axial direction, each group of piezoelectric ceramic sheets 3 is composed of n piezoelectric ceramic sheets, and each group of piezoelectric ceramic sheets 3 consists of n piezoelectric ceramic sheets. The ceramic sheets are correspondingly distributed on each plane of the outer surface of the elastic sleeve 2 of the metal tube;

The piezoelectric ceramic sheet 3 is polarized along the thickness direction, and the upper surface and the lower surface of the piezoelectric ceramic sheet 3 are plated with silver electrodes.

Figures 1 to 4 show a rotary-linear ultrasonic motor using a metal tube stator with a symmetrical structure in the second-order bending vibration mode. The metal tube elastic sleeve 2 has a symmetrical structure, and the cross section of the metal tube elastic sleeve 2 is square. Hollow columnar symmetrical structure, and its inner hole is processed with thread pair, metal tube elastic sleeve 2 and two groups of piezoelectric ceramic sheets 3 constitute the stator of ultrasonic motor, the outer surface of thread output shaft 1 is processed with metal tube elastic sleeve 2 matched thread pairs.

In this embodiment, all piezoelectric ceramic sheets 3 adopt the d ₃₁ vibration mode. There are thin silver electrodes on the surface of piezoelectric ceramic sheets 3 . In Fig. 1 to Fig. 4, the piezoelectric ceramic sheet 3 is divided into two excitation groups along the axial direction of the metal tube elastic sleeve 2, and the polarization direction of the adjacent piezoelectric ceramic sheet 3 along the axial direction of the metal tube elastic sleeve 2 On the contrary, along the circumferential direction of the elastic sleeve 2 of the metal tube, the piezoelectric ceramic sheets 3 are equally divided into two groups according to the polarization direction, one group is from outside to inside, and the other group is from inside to outside. The polarization direction of the piezoelectric ceramic sheet 3 cooperates with the energization mode to achieve the maximum output torque.

为相位差；第二组激振组中与第一组激振组中一对压电陶瓷片3相应的那对压电陶瓷片3通交流电信号为-sinωt，第二组激振组中与第一组激振组中另外一对压电陶瓷片3相应的那对压电陶瓷片3通交流电信号为

金属管弹性套筒2外表面接地。其中交流电信号的频率ω一般应与该定子二阶弯曲振动共振频率相吻合或相近，由此达到激发定子空间相互正交的二阶弯曲振动模态的效果，相位差一般为90或270度，利用振动耦合在定子的两个自由端的内表面耦合产生驱动行波，在轴向负载力的作用下经由螺纹副实现螺纹输出轴1一个方向的旋转-直线运动输出；当相位差

由90变为270度时，可使螺纹输出轴1产生相反方向的旋转-直线运动输出，参见图4。As shown in Figure 2 and Figure 3, two groups of piezoelectric ceramic sheets 3 are placed at the center of the two amplitudes of the second-order bending vibration of the metal tube elastic sleeve 2, and the ultrasonic motor can be fixed by flanges and screws when in use. At the vibration nodes of the stator. The specific power-on method is as follows: a pair of piezoelectric ceramic sheets opposite to each other in the first group of excitation groups. Chip 3-way AC signal for

is the phase difference; in the second group of excitation groups, the pair of piezoelectric ceramic sheets 3 corresponding to the pair of piezoelectric ceramic sheets 3 in the first group of excitation groups has an alternating current signal of -sinωt, and in the second group of excitation groups The pair of piezoelectric ceramic sheets 3 corresponding to the other pair of piezoelectric ceramic sheets 3 in the first group of excitation groups have an alternating current signal as

The outer surface of the metal tube elastic sleeve 2 is grounded. The frequency ω of the AC signal should generally coincide with or be close to the resonant frequency of the second-order bending vibration of the stator, thereby achieving the effect of exciting the second-order bending vibration modes orthogonal to each other in the space of the stator, and the phase difference Generally 90 or 270 degrees, use vibration coupling to couple the inner surfaces of the two free ends of the stator to generate driving traveling waves, and realize the rotation-linear motion output of the threaded output shaft 1 in one direction through the thread pair under the action of the axial load force; When the phase difference

When changing from 90 to 270 degrees, the threaded output shaft 1 can produce the opposite direction of rotation-linear motion output, see Figure 4.

第二激振组中压电陶瓷片3与第一激振组中相应的压电陶瓷片3的通电信号相反；第二激振组中压电陶瓷片3的通电方向与上述类同，金属管弹性套筒2接地。其中该交流电信号的频率ω一般应与该定子三阶弯曲振动共振频率相吻合或相近，由此达到激发定子空间相互正交的三阶弯曲振动模态的效果，相位差

一般为90或270度，利用振动耦合在定子的两个自由端的内表面耦合产生驱动行波，在轴向负载力的作用下经由螺纹副实现螺纹输出轴1一个方向的旋转-直线运动输出；当相位差

由90变为270度时，可使螺纹输出轴1产生相反方向的旋转-直线运动输出，参见图7。Figures 5 to 7 are rotary-linear ultrasonic motors with metal tube stators with symmetrical structures in third-order bending vibration modes. The piezoelectric ceramic sheets 3 are divided into three groups, and the three groups of piezoelectric ceramic sheets 3 form three excitation groups. A group of piezoelectric ceramic sheets 3 are respectively placed at the center of the three amplitudes of the third-order bending vibration of the metal tube elastic sleeve 2. When the ultrasonic motor is in use, it can be fixed at the vibration node of the stator through flanges and screws, as shown in the figure 6 and 7, the specific power supply method is: the AC signal of a pair of opposite piezoelectric ceramic sheets in the first excitation group can be sinωt, and the other pair of ceramic sheets is 3-pass

The energization signal of the piezoelectric ceramic sheet 3 in the second excitation group is opposite to that of the corresponding piezoelectric ceramic sheet 3 in the first excitation group; the energization direction of the piezoelectric ceramic sheet 3 in the second excitation group is similar to the above, and the metal The tube elastic sleeve 2 is grounded. The frequency ω of the AC signal should generally coincide with or be close to the resonant frequency of the third-order bending vibration of the stator, thereby achieving the effect of exciting the third-order bending vibration modes orthogonal to each other in the space of the stator, and the phase difference

Generally 90 or 270 degrees, use vibration coupling to couple the inner surfaces of the two free ends of the stator to generate driving traveling waves, and realize the rotation-linear motion output of the threaded output shaft 1 in one direction through the threaded pair under the action of the axial load force; When the phase difference

When changing from 90 to 270 degrees, the threaded output shaft 1 can produce the opposite direction of rotation-linear motion output, see FIG. 7 .

Specific Embodiment 2: The present embodiment will be described below with reference to FIGS. 8 to 12. The thread-driven rotary linear ultrasonic motor using the high-order bending vibration mode of the columnar stator described in this embodiment includes a threaded output shaft 1, a metal tube elastic Sleeve 2 and m groups of piezoelectric ceramic sheets 3, m is a positive integer,

The metal tube elastic sleeve 2 is sleeved on the outer surface of the threaded output shaft 1, and is connected with the threaded output shaft 1 through a thread pair. The outer contour of the cross section of the metal tube elastic sleeve 2 is composed of a circular arc and two straight lines. A shape composed of arcs greater than or equal to one-half of the circumference, and two straight line segments of equal length and perpendicular to each other;

On the outer surface of the metal tube elastic sleeve 2, m groups of piezoelectric ceramic sheets 3 are evenly distributed in the axial direction, and each group of piezoelectric ceramic sheets 3 is composed of two piezoelectric ceramic sheets, and each group of piezoelectric ceramic sheets 3 consists of two piezoelectric ceramic sheets. The ceramic sheets are correspondingly distributed on two planes on the outer surface of the elastic sleeve 2 of the metal tube;

The piezoelectric ceramic sheet 3 is polarized along the thickness direction, and the upper surface and the lower surface of the piezoelectric ceramic sheet 3 are plated with silver electrodes.

Figures 8 to 10 are rotary-linear ultrasonic motors utilizing second-order bending vibration mode asymmetric metal tube stators. The cross-section of the metal tube elastic sleeve 2 is a hollow cylindrical asymmetric structure with a semicircle and a half square. A pair of threads is processed, the metal tube elastic sleeve 2 and two groups of piezoelectric ceramic sheets 3 constitute the stator of the ultrasonic motor, and the thread output shaft 1 is processed with a thread pair matched with the metal tube elastic sleeve 2 .

The piezoelectric ceramic sheet 3 adopts the d ₃₁ vibration mode, and its upper and lower surfaces are plated with thin silver electrodes, and when energized and excited, the strain, that is, the deformation direction is perpendicular to the polarization direction. The piezoelectric ceramic sheets 3 are divided into two excitation groups along the circumferential direction of the elastic sleeve 2 of the metal tube, and the polarization direction of each group of piezoelectric ceramic sheets 3 is from outside to inside or from inside to outside. The polarization direction of the piezoelectric ceramic sheet 3 cooperates with the energization mode to achieve the maximum output torque.

Two groups of piezoelectric ceramic sheets 3 are placed at the central amplitude of the two amplitudes of the second-order bending vibration of the metal tube elastic sleeve 2. When the ultrasonic motor is in use, it can be fixed at the vibration node of the stator through flanges and screws. See As shown in Fig. 9 and Fig. 10, the specific power supply method is as follows: the two piezoelectric ceramic sheets 3 in the first vibration group respectively pass the alternating current signal, which can be sinωt and -sinωt, and the two piezoelectric ceramic sheets 3 in the second vibration group do not When electrified, the metal tube elastic sleeve 2 is grounded. In this embodiment, the frequency ω of the AC signal should generally coincide with or be close to the resonance frequency of the second-order bending vibration of the asymmetric structure stator, thereby achieving the effect of exciting the second-order bending vibration mode of the stator in one direction. Asymmetric structure, so that the driving waves can be generated by coupling the inner surfaces of the two free ends of the stator by means of vibration coupling, and under the action of the axial load force, the rotation-linear motion output of the thread output shaft 1 in one direction can be realized through the thread pair ; When the two piezoelectric ceramic sheets 3 in the second excitation group pass through the AC signal sinωt and -sinωt respectively, the two piezoelectric ceramic sheets 3 in the first excitation group are not powered, and the metal tube elastic sleeve 2 is grounded. Using the same principle, the output of rotation-linear motion in the opposite direction of the screw output shaft 1 can be realized.

Fig. 11 and Fig. 12 are the rotary-linear ultrasonic motors using the third-order bending vibration mode asymmetric metal tube stator. There is a pair of threads, the metal tube elastic sleeve 2 and three groups of piezoelectric ceramic sheets 3 constitute the stator of the ultrasonic motor, and the outer surface of the threaded output shaft 1 is processed with a thread pair matched with the metal tube elastic sleeve 2 .

The piezoelectric ceramic sheet 3 adopts the d ₃₁ vibration mode. This type of piezoelectric sheet is polarized along the thickness direction, and the upper and lower surfaces are plated with thin silver electrodes. All piezoelectric ceramic sheets 3 are divided into two excitation groups along the circumferential direction, each excitation group includes three piezoelectric ceramic sheets 3, and the piezoelectric ceramic sheets 3 of the two excitation groups are placed on the metal tube elastic sleeve 2 At the central amplitude of the three amplitudes of the third-order bending vibration, the ultrasonic motor can be fixed at the vibration node of the stator through flanges and screws when in use, see Figure 12.

The specific power-on method is: the three piezoelectric ceramic sheets 3 in the first excitation group are connected with alternating current signals, which can be sinωt, -sinωt and sinωt, and the three piezoelectric ceramic sheets 3 in the second excitation group are not energized. The metal tube elastic sleeve 2 is grounded. The frequency ω of the AC signal should generally coincide with or be close to the resonance frequency of the third-order bending vibration of the asymmetric structure stator, thereby achieving the effect of exciting the third-order bending vibration mode of the stator in one direction. Since the stator adopts an asymmetric structure, so that the driving wave can be generated by coupling the inner surfaces of the two free ends of the stator through vibration coupling, and under the action of the axial load force, the rotation-linear motion output of the thread output shaft 1 in one direction can be realized through the thread pair; when The three piezoelectric ceramic sheets 3 in the second excitation group pass through the AC signals sinωt, -sinωt and sinωt respectively, the three piezoelectric ceramic sheets 3 in the first excitation group are not energized, and the metal tube elastic sleeve 2 is grounded. The same principle can realize the rotation-linear motion output of the screw output shaft 1 in the opposite direction.

Specific Embodiment Three: The present embodiment will be described below in conjunction with FIG. 2 and FIG. 6. This embodiment is a further description of Embodiment 1 or 2. The m groups of piezoelectric ceramic sheets 3 are respectively located at m At the central amplitude of the m amplitudes of the first-order bending vibration.

Embodiment 4: This embodiment is a further description of Embodiment 1, 2 or 3. The piezoelectric ceramic sheet 3 is bonded and fixed to the outer surface of the metal tube elastic sleeve 2 by epoxy resin glue.

The piezoelectric ceramic sheet 3 and the metal tube elastic sleeve 2 can also be fixed by cold welding.

Embodiment 5: This embodiment is a further description of Embodiments 1, 2, 3 or 4. The metal tube elastic sleeve 2 is made of titanium alloy, copper alloy, alloy steel or aluminum alloy;

The piezoelectric ceramic sheet 3 is made of piezoelectric ceramic material with piezoelectric effect.

The piezoelectric ceramic sheet 3 described in this embodiment can be made of PZT4, PZT-5, PZT-8 or PMNT.

Specific Embodiment Six: The present embodiment will be described below with reference to FIGS. 13 to 18. The thread-driven rotary linear ultrasonic motor using the high-order bending vibration mode of the columnar stator described in this embodiment includes a threaded output shaft 1, a piezoelectric ceramic Tube 4, two metal caps 5 and p group of external electrodes 6-2, p is a positive integer,

The two ends of the piezoelectric ceramic tube 4 are respectively bonded with a metal cap 5 to form a stator, and the stator is sleeved on the outside of the threaded output shaft 1, and the two metal caps 5 are connected with the threaded output shaft 1 through a pair of threads.

The inner surface of the piezoelectric ceramic tube 4 is covered with internal electrodes 6-1, and the outer surface of the piezoelectric ceramic tube 4 is evenly distributed along the axial direction in p groups of external electrodes 6-2, and each group of external electrodes 6-2 includes q external electrodes , the value of q is an integer multiple of 4, and the q external electrodes in each group of external electrodes 6-2 are evenly distributed and fixed along the circumferential direction of the piezoelectric ceramic tube 4,

The piezoelectric ceramic tube 4 is polarized in the radial direction.

As shown in Fig. 13 to Fig. 15, it is a rotary-linear ultrasonic motor utilizing a piezoelectric tube stator in a second-order bending vibration mode. The outer surface of the piezoelectric ceramic tube 4 is evenly distributed with eight radially polarized coils for exciting vibration and electrification. In order to effectively excite the external electrode 6-2, the external electrode is preferably arranged at the center of the vibration amplitude of the corresponding bending vibration, mainly using the second-order or higher-order bending vibration mode of the piezoelectric tube stator, and the motor can be used through the flange Cooperate with the screw and fix at the vibration node of the stator; the inner hole of the metal cap 5 is processed with a thread pair, and the outer surface of the threaded output shaft 1 is processed with a thread pair matched with the metal cap 5 .

一般为90或270度，利用振动耦合在定子的两个自由端金属帽5的内表面耦合产生驱动行波，在轴向负载力的作用下经由螺纹副实现螺纹输出轴1一个方向的旋转-直线运动输出；当相位差

由90变为270度时，可使螺纹输出轴1产生相反方向的旋转-直线运动输出，参见图13与图14。The piezoelectric ceramic tube 4 is polarized along the radial direction, and adopts the d ₃₁ vibration mode. The eight external electrodes are divided into two excitation groups along the axial direction of the piezoelectric ceramic tube 4. The specific power supply method is: the first excitation group The four outer electrodes 6-2 in the middle pass the alternating current signal sequentially along the circumferential direction and can be sinωt, -sinωt and The energization signals of the external electrodes 6-2 in the second excitation group are opposite to those of the corresponding external electrodes 6-2 in the first excitation group; the inner surface of the piezoelectric ceramic tube 4 is a virtual ground. The frequency ω of the AC signal should generally coincide with or be close to the resonant frequency of the second-order bending vibration of the stator, thereby achieving the effect of exciting the second-order bending vibration modes orthogonal to each other in the space of the stator, and the phase difference

Generally, it is 90 or 270 degrees. Vibration coupling is used to couple the inner surfaces of the metal caps 5 at the two free ends of the stator to generate driving waves. Under the action of axial load force, the rotation of the threaded output shaft 1 in one direction is realized through the threaded pair- Linear motion output; when the phase difference

When changing from 90 degrees to 270 degrees, the threaded output shaft 1 can produce the opposite direction of rotation-linear motion output, see Fig. 13 and Fig. 14 .

-sinωt和

第二个激振组中外电极6-2与第一个激振组中相应的外电极6-2的通电信号相反；第三个激振组中外电极6-2与第一个激振组中相应的外电极6-2的通电信号相同，压电陶瓷管4内表面虚地。其中该交流电信号的频率ω一般应与该定子三阶弯曲振动共振频率相吻合或相近，由此达到激发定子空间相互正交的三阶弯曲振动模态的效果，相位差

一般为90或270度，利用振动耦合在定子的两个自由端金属帽5的内表面耦合产生驱动行波，在轴向负载力的作用下经由螺纹副实现螺纹输出轴1一个方向的旋转-直线运动输出；当相位差

由90变为270度时，可使螺纹输出轴1产生相反方向的旋转-直线运动输出，参见图18。As shown in Fig. 16 to Fig. 18, it is a rotary-linear ultrasonic motor utilizing a piezoelectric tube stator in a third-order bending vibration mode, and twelve radially polarized electrodes are evenly distributed on the outer surface of the piezoelectric ceramic tube 4 for excitation and vibration energization. The external electrodes used are preferably arranged at the center of the vibration amplitude of the corresponding bending vibration in order to effectively excite the external electrodes, mainly using the third-order or higher-order bending vibration modes of the piezoelectric tube stator, and the motor can be used through flanges and screws. Cooperate and fix at the vibration node of the stator; the twelve external electrodes can be divided into three groups for excitation, and the twelve external electrodes are divided into three excitation groups along the axial direction of the piezoelectric ceramic tube 4. The specific power supply method For: the four external electrodes 6-2 in the first excitation group pass the alternating current signal sequentially along the circumferential direction, which can be sinωt,

-sinωt and

The external electrode 6-2 in the second excitation group is opposite to the energization signal of the corresponding external electrode 6-2 in the first excitation group; the external electrode 6-2 in the third excitation group is the same as the first excitation group The energization signals of the corresponding external electrodes 6-2 are the same, and the inner surface of the piezoelectric ceramic tube 4 is a virtual ground. The frequency ω of the AC signal should generally coincide with or be close to the resonant frequency of the third-order bending vibration of the stator, thereby achieving the effect of exciting the third-order bending vibration modes orthogonal to each other in the space of the stator, and the phase difference

Generally, it is 90 or 270 degrees. Vibration coupling is used to couple the inner surfaces of the metal caps 5 at the two free ends of the stator to generate driving waves. Under the action of axial load force, the rotation of the threaded output shaft 1 in one direction is realized through the threaded pair- Linear motion output; when the phase difference

When changing from 90 to 270 degrees, the threaded output shaft 1 can be rotated in the opposite direction-linear motion output, see Figure 18.

Embodiment 7: This embodiment is a further description of Embodiment 6. In this embodiment, the piezoelectric ceramic tube 4 and the metal cap 5 are bonded and fixed by epoxy resin.

The piezoelectric ceramic tube 4 and the metal cap 5 can also be fixed by cold welding.

Embodiment 8: This embodiment is a further description of Embodiment 6 or 7. The material of the metal cap 5 is titanium alloy, copper alloy, alloy steel or aluminum alloy;

The piezoelectric ceramic tube 4 is made of piezoelectric ceramic material with piezoelectric effect.

Embodiment 9: This embodiment is a further description of Embodiments 1, 2, 3, 4, 5, 6, 7 or 8. The two ends of the threaded output shaft 1 are of flat head structure or ball end structure.

Specific Embodiment 10: This embodiment is a further description of Embodiments 1, 2, 3, 4, 5, 6, 7, 8 or 9. The material of the threaded output shaft 1 is copper alloy, alloy steel metal or polystyrene Vinyl fluoride polymer material.

In the above-mentioned embodiments of the present invention, the piezoelectric material used in the piezoelectric ceramic sheet 3 or the piezoelectric ceramic tube 4 can also be selected from smart materials such as magnetostrictive materials or electrostatic materials.

Claims (10)

1. A thread-driven rotary linear ultrasonic motor utilizing a cylindrical stator high-order bending vibration mode, characterized in that: it includes a threaded output shaft (1), a metal tube elastic sleeve (2) and m groups of piezoelectric ceramic sheets (3), m is a positive integer, The metal tube elastic sleeve (2) is sleeved on the outer surface of the threaded output shaft (1), and is connected with the threaded output shaft (1) through a thread pair. The outer profile of the metal tube elastic sleeve (2) is positive in cross section. n-gon, the value of n is an integer multiple of 4, On the outer surface of the elastic sleeve (2) of the metal tube, m groups of piezoelectric ceramic sheets (3) are uniformly distributed along the axial direction, each group of piezoelectric ceramic sheets (3) is composed of n piezoelectric ceramic sheets, each group of piezoelectric ceramic sheets (3) n pieces of piezoelectric ceramic sheets are correspondingly distributed on each plane of the outer surface of the metal tube elastic sleeve (2); The piezoelectric ceramic sheet (3) is polarized along the thickness direction, and the upper surface and the lower surface of the piezoelectric ceramic sheet (3) are plated with silver electrodes. 2. A thread-driven rotary linear ultrasonic motor utilizing a high-order bending vibration mode of a cylindrical stator, characterized in that it includes a threaded output shaft (1), a metal tube elastic sleeve (2) and m groups of piezoelectric ceramic sheets (3), m is a positive integer, The metal tube elastic sleeve (2) is sleeved on the outer surface of the threaded output shaft (1), and is connected with the threaded output shaft (1) through a thread pair. The outer profile of the metal tube elastic sleeve (2) cross section is A shape consisting of an arc and two straight line segments, where the arc is greater than or equal to half the circumference, and the two straight line segments are equal in length and perpendicular to each other; On the outer surface of the elastic sleeve (2) of the metal tube, m groups of piezoelectric ceramic sheets (3) are uniformly distributed along the axial direction, each group of piezoelectric ceramic sheets (3) is composed of two piezoelectric ceramic sheets, each group of piezoelectric ceramic sheets The two piezoelectric ceramic sheets of (3) are correspondingly distributed on two planes on the outer surface of the metal tube elastic sleeve (2); The piezoelectric ceramic sheet (3) is polarized along the thickness direction, and the upper surface and the lower surface of the piezoelectric ceramic sheet (3) are plated with silver electrodes. 3. The thread-driven rotary linear ultrasonic motor utilizing the high-order bending vibration mode of the cylindrical stator according to claim 1 or 2, characterized in that: the m groups of piezoelectric ceramic sheets (3) are respectively located in the elastic sleeve of the metal tube The central amplitude of the m amplitudes of the m-order bending vibration of the cylinder (2). 4. The thread-driven rotary linear ultrasonic motor using the high-order bending vibration mode of the columnar stator according to claim 1 or 2, characterized in that: the piezoelectric ceramic sheet (3) is bonded to the metal tube by epoxy resin glue The outer surface of the elastic sleeve (2) is bonded and fixed. 5. The thread-driven rotary linear ultrasonic motor utilizing the high-order bending vibration mode of the cylindrical stator according to claim 1 or 2, characterized in that: the metal tube elastic sleeve (2) is made of titanium alloy, copper alloy, alloy steel or aluminum alloy; The piezoelectric ceramic sheet (3) is made of piezoelectric ceramic material with piezoelectric effect. 6. A thread-driven rotary linear ultrasonic motor utilizing a high-order bending vibration mode of a cylindrical stator, characterized in that it includes a threaded output shaft (1), a piezoelectric ceramic tube (4), and two metal caps (5) And p group of external electrodes (6-2), p is a positive integer, The two ends of the piezoelectric ceramic tube (4) are respectively bonded with a metal cap (5) to form a stator, and the stator is sleeved on the outside of the threaded output shaft (1), and the two metal caps (5) are connected to the threaded output shaft (1) ) are connected through a pair of threads, The inner surface of the piezoelectric ceramic tube (4) is covered with internal electrodes (6-1), and the outer surface of the piezoelectric ceramic tube (4) is evenly distributed along the axial direction in p groups of external electrodes (6-2), each group of external electrodes (6-2) includes q external electrodes, the value of q is an integer multiple of 4, and the q external electrodes in each group of external electrodes (6-2) are evenly distributed and fixed along the circumferential direction of the piezoelectric ceramic tube (4) , The piezoelectric ceramic tube (4) is polarized in radial direction. 7. The thread-driven rotary linear ultrasonic motor using the high-order bending vibration mode of the cylindrical stator according to claim 6, characterized in that: a ring is used between the piezoelectric ceramic tube (4) and the metal cap (5). Oxygen resin adhesive bonding. 8. The thread-driven rotary linear ultrasonic motor using the high-order bending vibration mode of the columnar stator according to claim 6 or 7, characterized in that: the material of the metal cap (5) is titanium alloy, copper alloy, alloy steel or aluminum alloy; The piezoelectric ceramic tube (4) is made of piezoelectric ceramic material with piezoelectric effect. 9. The thread-driven rotary linear ultrasonic motor using the high-order bending vibration mode of the columnar stator according to claim 1, 2 or 6, characterized in that: the two ends of the thread output shaft (1) are flat head structures or For the ball end structure. 10. The thread-driven rotary linear ultrasonic motor utilizing the high-order bending vibration mode of the cylindrical stator according to claim 1, 2 or 6, characterized in that: the thread output shaft (1) is made of copper alloy or alloy steel Metal or polytetrafluoroethylene polymer materials.

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