CN105406759B - Partitioned excitation type longitudinal-bending composite ultrasonic motor vibrator - Google Patents

Abstract

A partition excitation type longitudinal bending composite ultrasonic motor vibrator belongs to the technical field of piezoelectric ultrasonic motors. The vibrator solves the problems that the energy conversion efficiency is low and the optimal arrangement is difficult to realize due to the independent arrangement of longitudinal vibration ceramic and bending vibration ceramic in the conventional longitudinal and bending composite ultrasonic motor vibrator. The piezoelectric ceramic of the whole piece realizes the excitation of longitudinal and bending composite vibration, wherein the middle position of the ceramic is used for exciting longitudinal vibration, the ceramics at the two sides are used for exciting bending vibration, the longitudinal vibration ceramic and the bending vibration ceramic are not separately arranged any more, and the positions of the longitudinal vibration ceramic and the bending vibration ceramic in the axial direction are overlapped, so that the problems of low energy conversion efficiency and difficult realization of optimal arrangement are solved; the longitudinal and bending composite excitation is realized by adopting the whole ceramic wafer, and the problems of low electromechanical coupling efficiency, serious heating and the like caused by exciting bending vibration by a half-wafer bending vibration ceramic combination mode in the traditional scheme are avoided. The invention is suitable for the field of ultrasonic motor vibrator manufacturing.

Description

Partition-excited Longitudinal-bending Composite Ultrasonic Motor Vibrator

technical field

The invention relates to a section-excited longitudinal-bending composite ultrasonic motor vibrator, which belongs to the technical field of piezoelectric ultrasonic motors.

Background technique

Piezoelectric ultrasonic motor is a kind of piezoelectric ultrasonic motor that uses the inverse piezoelectric effect of piezoelectric ceramics to excite vibration in the ultrasonic frequency range in the elastic body, and forms a particle motion with a specific trajectory at a specific point or area on the surface of the elastic body, and then passes through the stator, The frictional coupling between the rotors converts the microscopic motion of the particle into the macroscopic motion of the rotor. It has the advantages of simple structure, flexible design, low speed, high torque/thrust, high power/torque density, high positioning accuracy, fast response speed, and self-locking when power is off. , No electromagnetic interference and not subject to electromagnetic interference.

Piezoelectric ultrasonic drive technology is a kind of inverse piezoelectric effect of piezoelectric ceramics, which excites vibration in the ultrasonic frequency range in the elastic body, forms a particle motion with a specific trajectory at a specific point or area on the surface of the elastic body, and then passes through the stator , The frictional coupling between the rotors converts the microscopic motion of the particle into the macroscopic motion of the rotor. Piezoelectric ultrasonic driver has the advantages of low speed and high torque, no need for speed change mechanism, no electromagnetic interference, fast response and self-locking when power is off.

The vibrator of the longitudinal-bending composite ultrasonic motor is driven by the combination of longitudinal vibration and bending vibration of the vibrator elastic body. In the traditional longitudinal-bending composite ultrasonic motor vibrator, the piezoelectric ceramic elements that excite the longitudinal vibration and bending vibration are generally set separately, that is, the longitudinal vibration Vibrating ceramics are used to excite longitudinal vibrations, and bending vibrating ceramics are used to excite bending vibrations; for example, the publication date is August 22, 2007, the publication number is CN101022256, and the invention name is "Sandwich Transducer Type Longitudinal Bending with FM Horn". "Linear Ultrasonic Motor" patent application, which proposes a sandwich transducer type longitudinal bending linear ultrasonic motor with a frequency modulation horn, which solves the problems of low motor efficiency and high noise in the existing sandwich longitudinal bending composite linear ultrasonic motor , serious wear and tear, difficult to serialize and other deficiencies, it has the advantages of high efficiency, large output, and serial production. However, the ultrasonic motor vibrator uses longitudinal vibration ceramics and bending vibration ceramics to excite longitudinal vibration and bending vibration respectively, and the two ceramics are located at different positions in the axial direction of the vibrator; The optimal setting position of the bending vibration ceramics is often overlapped; therefore, this method of independently setting the piezoelectric element limits the improvement of its energy conversion efficiency, which is not conducive to achieving the optimal arrangement of the piezoelectric ceramics; in addition, this method The bending vibration ceramic in the vibrator is composed of two half pieces of piezoelectric ceramics with opposite polarization directions. Due to the unavoidable thickness deviation in the process of bending vibration ceramics, the combination of half pieces of ceramics will make each bending vibration ceramics. The tightening force is inconsistent, which greatly reduces the electromechanical coupling efficiency and causes serious heating problems.

Contents of the invention

The present invention aims to solve the problems of low energy conversion efficiency and difficulty in achieving optimal arrangement caused by the independent arrangement of longitudinal vibration ceramics and bending vibration ceramics existing in the existing longitudinal-bending composite ultrasonic motor vibrator, and the half-piece bending vibration ceramics Due to the problems of low electromechanical coupling efficiency and serious heat generation caused by the combination method, the present invention provides a partition-excited longitudinal-bending composite ultrasonic motor vibrator.

Partition-excited longitudinal-bending composite ultrasonic motor vibrator, which includes a separator 1, eight piezoelectric ceramic sheets 2, two end covers 3, two driving feet 4, four ground electrode sheets 5, and four longitudinal vibration electrode sheets 6 And eight bending vibration electrode sheets 7;

Two studs 1-1 are arranged symmetrically on the left and right sides of the partition 1, and the two studs 1-1 are perpendicular to the partition 1; superior;

On the same side of the separator 1, the four piezoelectric ceramic sheets 2 starting from the separator 1 are respectively called the first piezoelectric ceramic sheet, the second piezoelectric ceramic sheet, the third piezoelectric ceramic sheet and the first piezoelectric ceramic sheet. Four pieces of piezoelectric ceramics; two end caps 3 are respectively screwed on the ends of two studs 1-1 for clamping the piezoelectric ceramics 2;

The two driving feet are respectively fixed at the end positions of the upper sides of the two end covers 3;

The eight piezoelectric ceramic sheets 2 are all polarized along the thickness direction, and the two adjacent piezoelectric ceramic sheets 2 have opposite polarization directions;

A ground electrode sheet 5 is arranged between the second piezoelectric ceramic sheet and the third piezoelectric ceramic sheet on the left side of the separator 1, and between the fourth piezoelectric ceramic sheet and the left end cover 3; A ground electrode sheet 5 is provided between the second piezoelectric ceramic sheet and the third piezoelectric ceramic sheet 2 on the side, and between the fourth piezoelectric ceramic sheet and the right end cover 3;

A longitudinal vibration electrode sheet 6 and a Two bending vibration electrode sheets 7; between the first piezoelectric ceramic sheet and the second piezoelectric ceramic sheet on the right side of the separator 1, between the third piezoelectric ceramic sheet and the fourth piezoelectric ceramic sheet 2 One longitudinal vibration electrode piece 6 and two bending vibration electrode pieces 7 are provided;

One longitudinal vibration electrode piece 6 and two bending vibration electrode pieces 7 are arranged in the same plane, the longitudinal vibration electrode piece 6 is set on the stud 1-1, and the two bending vibration electrode pieces 7 are symmetrically arranged on the longitudinal vibration electrode piece 6, and there is a gap between the bending electrode sheet 7 and the longitudinal vibration electrode sheet 6.

All the ground electrode sheets 5 are connected to the common end of the excitation signal, the four longitudinal vibration electrode sheets 6 are connected to the first phase drive signal, the two bending electrode sheets 7 on the upper left side of the separator 1 and the lower right side of the separator 1 The two bending vibration electrode pieces 7 of the diaphragm 1 are connected to the second phase drive signal, the two bending vibration electrode pieces 7 on the left lower part of the separator 1 and the two bending vibration electrode pieces 7 on the right upper part of the separator 1 are connected to the third Phase drive signal connection; all drive signals are AC excitation signals, and the signal waveform is square wave, sine wave, trapezoidal wave or triangular wave; there is a 90-degree phase difference between the first-phase drive signal and the second-phase drive signal in time, There is a 180-degree phase difference between the second-phase driving signal and the third-phase driving signal in time.

The cross section of the end cap 3 is greater than or equal to the cross section of the piezoelectric ceramic sheet 2 .

The cross section of the separator 1 is larger than that of the piezoelectric ceramic sheet 2 .

The partition-excited longitudinal-bending composite ultrasonic motor vibrator of the present invention utilizes the combination of the odd-order longitudinal vibration and the even-order bending vibration of the composite beam to realize the linear actuation of the two feet; the middle part of the piezoelectric ceramic applies the same AC excitation through the longitudinal vibration electrode sheet The signal generates synchronous expansion and contraction deformation, and then excites the longitudinal vibration of the vibrator; the two sides of the piezoelectric ceramic are respectively applied with two-phase excitation signals with a phase difference of 180 degrees through the bending vibration electrode sheet, and the upper and lower sides of the piezoelectric ceramic will generate Alternate expansion and contraction, and then excite the bending vibration of the vibrator; when the resonant frequency of the odd-order longitudinal vibration and the even-order bending vibration of the ultrasonic motor vibrator are very close, and the longitudinal vibration and bending vibration have a 90-degree phase difference in time, then it can be Through the combination of longitudinal vibration and bending vibration, the vibration of the elliptical trajectory is excited at the two driving feet, and the rotation direction of the vibration trajectory of the two driving feet is consistent, so that the vibrator can be actuated in a straight line (see Figure 8, where 8 is the mover) ; Adjust the phase difference between the longitudinal vibration and the bending vibration to -90 degrees, then the reverse drive can be realized.

The partition-excited longitudinal-bending composite ultrasonic motor vibrator of the present invention uses a whole piece of piezoelectric ceramics to realize the excitation of longitudinal-bending composite vibrations, wherein the middle position of the ceramics is used to excite longitudinal vibrations, and the ceramics on both sides are used to excite bending vibrations , longitudinal vibration ceramics and bending vibration ceramics are no longer set separately, and their positions in the axial direction are coincident. The energy conversion efficiency caused by independent setting is low, and it is difficult to achieve the optimal layout; moreover, the whole piece of ceramic sheet is used to realize the composite excitation of longitudinal bending, which avoids the combination of half-piece bending vibration ceramics in the traditional scheme to excite bending vibration The problems of low electromechanical coupling efficiency and serious heat generation are brought about.

The partition-excited longitudinal-bending composite ultrasonic motor vibrator of the present invention has high energy conversion efficiency, low heat generation, and is easy to realize the optimal arrangement of piezoelectric ceramics. It is very simple to process and assemble, and is convenient to realize serialization and commercialization.

The invention is applicable to the field of manufacturing ultrasonic motor vibrators.

Description of drawings

Fig. 1 is a three-dimensional structural schematic diagram of a partition-excited longitudinal-bending composite ultrasonic motor vibrator according to the present invention;

Fig. 2 is a cross-sectional view of the section-excited longitudinal-bending composite ultrasonic motor vibrator shown in Fig. 1;

Fig. 3 is a schematic diagram of the polarization direction of the piezoelectric ceramic 2 in the vibrator of the partition-excited longitudinal-bending composite ultrasonic motor shown in Fig. 1;

Fig. 4 is a perspective view of the section-excited longitudinal bending composite ultrasonic motor vibrator shown in Fig. 1 after the left end cover 3 is removed;

Fig. 5 is a perspective view of the section-excited longitudinal bending composite ultrasonic motor vibrator shown in Fig. 1 after the left end cover 3 and a piece of piezoelectric ceramic 2 are removed;

Fig. 6 is a longitudinal vibration modal diagram of the vibrator of the partition-excited longitudinal-bending composite ultrasonic motor shown in Fig. 1;

Fig. 7 is a diagram of the mode shape of the bending vibration of the vibrator of the partition-excited longitudinal-bending composite ultrasonic motor shown in Fig. 1;

Fig. 8 is a schematic diagram of moving the mover when the section-excited longitudinal-bending composite ultrasonic motor vibrator shown in Fig. 1 is working.

detailed description

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 1. This embodiment will be specifically described with reference to FIGS. 1 to 8. The section-excited longitudinal-bending composite ultrasonic motor vibrator described in this embodiment includes a separator 1, eight piezoelectric ceramic sheets 2, two terminal Cover 3, two driving feet 4, four ground electrode sheets 5, four longitudinal vibration electrode sheets 6 and eight bending vibration electrode sheets 7;

Two studs 1-1 are arranged symmetrically on the left and right sides of the partition 1, and the two studs 1-1 are perpendicular to the partition 1; superior;

On the same side of the separator 1, the four piezoelectric ceramic sheets 2 starting from the separator 1 are respectively called the first piezoelectric ceramic sheet, the second piezoelectric ceramic sheet, the third piezoelectric ceramic sheet and the first piezoelectric ceramic sheet. Four pieces of piezoelectric ceramics; two end caps 3 are respectively screwed on the ends of two studs 1-1 for clamping the piezoelectric ceramics 2;

The two driving feet are respectively fixed at the end positions of the upper sides of the two end covers 3;

The eight piezoelectric ceramic sheets 2 are all polarized along the thickness direction, and the two adjacent piezoelectric ceramic sheets 2 have opposite polarization directions;

A ground electrode sheet 5 is arranged between the second piezoelectric ceramic sheet and the third piezoelectric ceramic sheet on the left side of the separator 1, and between the fourth piezoelectric ceramic sheet and the left end cover 3; A ground electrode sheet 5 is provided between the second piezoelectric ceramic sheet and the third piezoelectric ceramic sheet 2 on the side, and between the fourth piezoelectric ceramic sheet and the right end cover 3;

A longitudinal vibration electrode sheet 6 and a Two bending vibration electrode sheets 7; between the first piezoelectric ceramic sheet and the second piezoelectric ceramic sheet on the right side of the separator 1, between the third piezoelectric ceramic sheet and the fourth piezoelectric ceramic sheet 2 One longitudinal vibration electrode piece 6 and two bending vibration electrode pieces 7 are provided;

One longitudinal vibration electrode piece 6 and two bending vibration electrode pieces 7 are arranged in the same plane, the longitudinal vibration electrode piece 6 is set on the stud 1-1, and the two bending vibration electrode pieces 7 are symmetrically arranged on the longitudinal vibration electrode piece 6, and there is a gap between the bending electrode sheet 7 and the longitudinal vibration electrode sheet 6.

In this embodiment, eight piezoelectric ceramic sheets 2 are symmetrically set on two studs 1-1, that is, four piezoelectric ceramic sheets 2 are set on the stud 1-1 on the left side of the partition 1, and the other four pieces The piezoelectric ceramic sheet 2 is set on the stud 1-1 on the right side of the separator 1.

On the same side of the separator 1, the four piezoelectric ceramic sheets 2 starting from the separator 1 are respectively called the first piezoelectric ceramic sheet, the second piezoelectric ceramic sheet, the third piezoelectric ceramic sheet and the first piezoelectric ceramic sheet. Four piezoelectric ceramic sheets; that is, a piezoelectric ceramic sheet 2 next to the separator 1 on the same side of the separator 1 is called the first piezoelectric ceramic sheet, and a piezoelectric ceramic sheet next to the first piezoelectric ceramic sheet Sheet 2 is called the second piezoelectric ceramic sheet, and the piezoelectric ceramic sheet 2 next to the second piezoelectric ceramic sheet is called the third piezoelectric ceramic sheet, and the one next to the third piezoelectric ceramic sheet is called the third piezoelectric ceramic sheet. Electric ceramic sheet 2 is called the fourth piezoelectric ceramic sheet

Embodiment 2. The difference between this embodiment and the section-excited longitudinal-bending composite ultrasonic motor vibrator described in Embodiment 1 is that all ground electrode sheets 5 are connected to the common end of the excitation signal, and the four longitudinal vibration electrode sheets 6 are connected to the first One-phase drive signal connection, the two bending vibration electrode sheets 7 on the upper left side of the separator 1 and the two bending vibration electrode sheets 7 on the lower right side of the separator 1 are connected to the second phase drive signal, the left side of the separator 1 The two bending electrode sheets 7 on the lower part of the side and the two bending electrode sheets 7 on the upper right side of the separator 1 are connected to the third-phase drive signal; all drive signals are AC excitation signals, and the signal waveform can be square wave, Sine wave, trapezoidal wave or triangular wave; there is a 90-degree phase difference between the first-phase driving signal and the second-phase driving signal in time, and a 180-degree phase between the second-phase driving signal and the third-phase driving signal in time Difference.

Embodiment 3. The difference between this embodiment and the section-excited longitudinal-bending composite ultrasonic motor vibrator described in Embodiment 1 is that the cross-section of the end cover 3 is greater than or equal to the cross-section of the piezoelectric ceramic sheet 2 .

Embodiment 4. The difference between this embodiment and the section-excited longitudinal-bending composite ultrasonic motor vibrator described in Embodiment 1 is that the cross-section of the separator 1 is larger than the cross-section of the piezoelectric ceramic sheet 2 .

Claims (4)

1. Partition-excited longitudinal bending composite ultrasonic motor vibrator, which includes a partition (1), eight piezoelectric ceramic sheets (2), two end covers (3), two driving feet (4), and four grounding electrodes sheet (5), four longitudinal vibration electrode sheets (6) and eight bending electrode sheets (7); It is characterized in that two studs (1-1) are arranged symmetrically on the left and right sides of the partition (1), and the two studs (1-1) are perpendicular to the partition (1); eight pieces of piezoelectric ceramics The sheet (2) is symmetrically set on the two studs (1-1); The four piezoelectric ceramic sheets (2) starting from the separator (1) on the same side of the separator (1) are respectively called the first piezoelectric ceramic sheet, the second piezoelectric ceramic sheet, and the third piezoelectric ceramic sheet. A piezoelectric ceramic sheet and a fourth piezoelectric ceramic sheet; the two end caps (3) are respectively screwed on the ends of the two studs (1-1) for clamping the piezoelectric ceramic sheet (2); The two driving feet are respectively fixedly arranged at the end positions of the upper sides of the two end covers (3); the eight piezoelectric ceramic sheets (2) are all polarized along the thickness direction, and the adjacent two piezoelectric ceramic sheets The polarization directions of the sheet (2) are opposite; A ground electrode sheet (5 ); between the second piezoelectric ceramic sheet and the third piezoelectric ceramic sheet (2) on the right side of the separator (1), and between the fourth piezoelectric ceramic sheet and the right end cover (3) are provided with Ground electrode sheet (5); A longitudinal vibration electrode is arranged between the first piezoelectric ceramic sheet and the second piezoelectric ceramic sheet on the left side of the separator (1), and between the third piezoelectric ceramic sheet and the fourth piezoelectric ceramic sheet (6) and two bending vibration electrode sheets (7); between the first piezoelectric ceramic sheet and the second piezoelectric ceramic sheet on the right side of the separator (1), the third piezoelectric ceramic sheet and the fourth piezoelectric ceramic sheet A longitudinal vibration electrode piece (6) and two bending vibration electrode pieces (7) are arranged between the piezoelectric ceramic pieces (2); One longitudinal vibration electrode piece (6) and two bending vibration electrode pieces (7) are arranged in the same plane, the longitudinal vibration electrode piece (6) is set on the stud (1-1), and the two bending vibration electrode pieces (7) symmetrically arranged on the upper and lower sides of the longitudinal vibration electrode sheet (6), and there is a gap between the bending vibration electrode sheet (7) and the longitudinal vibration electrode sheet (6). 2. The section-excited longitudinal-bending composite ultrasonic motor vibrator according to claim 1, characterized in that all ground electrode sheets (5) are connected to the common end of the excitation signal, and four longitudinal-vibration electrode sheets (6) are connected to the first phase Drive signal connection, the two bending vibration electrode sheets (7) on the left upper part of the separator (1) and the two bending vibration electrode sheets (7) on the right lower part of the separator (1) are connected to the second phase drive signal , the two bending electrode sheets (7) on the left lower part of the separator (1) and the two bending electrode sheets (7) on the right upper part of the separator (1) are connected with the third phase drive signal; all drive The signals are all AC excitation signals, and the signal waveform is square wave, sine wave, trapezoidal wave or triangular wave; there is a 90-degree phase difference between the first-phase drive signal and the second-phase drive signal in time, and the second-phase drive signal and the second-phase drive signal The three-phase drive signals have a phase difference of 180 degrees in time. 3. The section-excited longitudinal-bending composite ultrasonic motor vibrator according to claim 1, characterized in that the cross-section of the end cover (3) is greater than or equal to the cross-section of the piezoelectric ceramic sheet (2). 4. The section-excited longitudinal-bending composite ultrasonic motor vibrator according to claim 1, characterized in that the cross-section of the partition (1) is larger than the cross-section of the piezoelectric ceramic sheet (2).