CN113131786B - A rotary piezoelectric motor - Google Patents

Abstract

The invention relates to a rotary piezoelectric motor, which belongs to the technical field of precision driving and positioning. Including base, stator mechanism and mover mechanism. The base is an L-shaped base, and the upright plate of the base is a square frame; the stator mechanism includes a cross-shaped frame, two pairs of rotating piezoelectric sheets and two pairs of clamping piezoelectric sheets, and the two pairs of rotating piezoelectric sheets are set on a pair of vertical arms to form Drive unit; two pairs of clamping piezoelectric plates are set on a pair of horizontal arms to form a clamping unit; the stator mechanism is fixed in the square frame of the base; the mover mechanism includes an output shaft and a supporting slider; the output shaft passes through the bearing through the design The upper part of the supporting slider is matched with the lower part of the supporting slider on the base through the T-shaped slot. The invention uses sinusoidal signals to control the driving and clamping action of the stator, and realizes that the contact between the stator and the output shaft is abrupt, and the stator and the mover are driven by static friction without sliding friction. No wear, prolonging motor life.

Description

A rotary piezoelectric motor

technical field

The invention belongs to the technical field of precision driving and positioning, and in particular relates to a rotary piezoelectric motor.

Background technique

Piezoelectric motors, also known as ultrasonic motors, utilize the mechanical vibration of a vibrator through the inverse piezoelectric effect. The motion and torque of the motor is obtained by the friction between the vibrator and the slider (rotor). So far, they have been widely used in robots, high-precision instruments, and researchers like piezoelectric motors because of their superior advantages over electromagnetic motors, including compact and simple structure, no coils, fast response, weight and power consumption Minimum, self-locking in power-off state, and no electromagnetic interference, etc.

Piezoelectric motors can be classified into ultrasonic motors and quasi-static motors. The ultrasonic motor is driven by the friction between the stator and the mover to move the mover, and works in a resonance state with high frequency and fast speed. Because it is driven by a single harmonic, the process of the stator driving the mover is gradual, and there is sliding friction between the stator and the mover, which causes severe wear and short life. In 2016, Yang et al. created a longitudinal bending composite drive motor with a no-load speed of 342 rpm and a frequency of 57.47 kHz. Nevertheless, the maximum torque is only 6.26 N mm, and the high frequency brings high speed, but due to the driving principle of the friction coupling, the efficiency and service life of the motor are limited. The frequency of quasi-static motors is relatively low, such as inchworm motors. The inchworm motor realizes unidirectional movement through the cooperation of the clamping unit and the driving vibrator. Theoretically speaking, the inchworm motor has no sliding friction, no friction and wear during operation, high efficiency and long life. At the same time, this type of piezoelectric motor requires two tank units and one drive unit to act synchronously and alternately, which is relatively difficult from a control point of view and requires a relatively complicated circuit to achieve effective control.

Contents of the invention

In order to solve the shortcomings of severe friction and wear of the ultrasonic motor and low frequency and low speed of the quasi-static motor, the invention provides a rotary piezoelectric motor.

A rotary piezoelectric motor includes a base 4, a stator mechanism 3 and a mover mechanism.

The base 4 is an L-shaped base; the horizontal bottom plate of the base 4 is provided with an inverted T-shaped groove 41, and the upright plate of the base 4 is a square frame;

The stator mechanism 3 includes a cross-shaped frame 31, two pairs of rotating piezoelectric sheets 34 and two pairs of clamping piezoelectric sheets 35; the middle part of the cross-shaped frame is provided with a blind hole, and the blind hole is a circular platform notch 32; Rotating piezoelectric sheets 34 are respectively fixed on both sides of a pair of vertical arms 38 of the cross-shaped frame to form a drive unit; two pairs of clamping piezoelectric sheets 35 are respectively fixed on two sides of a pair of horizontal arms 33 of the cross-shaped frame. On the side, a clamping unit is formed; the cross-shaped frame 31 is fixedly connected and fixed in the square frame of the base 4 through the cantilever end of a pair of horizontal arms 33 and the inner wall of the square frame of the base 4, and the pair of vertical arms 38 The cantilever end is not in contact with the inner wall of the square frame of the base 4;

The mover mechanism includes an output shaft 1 and a supporting slider 2; the output shaft 1 is installed on the upper part of the supporting slider 2 through a bearing, and one end of the output shaft 1 is a circular table top 11, and the circular table top 11 of the output shaft 1 is located at ten In the round platform notch 32 of font frame; The bottom of support slide block 2 cooperates with inverted T-shaped groove 41 and is located on the base 4;

A pre-tightening mechanism is provided between the upright plate of the base 4 and the supporting slider 2 of the mover mechanism;

When working, a sinusoidal signal is input to two pairs of rotating piezoelectric sheets 34, and the elastic vibrator of a pair of vertical arms 38 drives the stator mechanism 3 to rotate forward or reverse alternately in one cycle; to two pairs of clamping piezoelectric sheets 35 Input a square wave signal, the elastic vibrator of a pair of horizontal arms 33 realizes the stator mechanism 3 to move back and forth in the direction perpendicular to the rotation plane in one cycle, and realizes the orifice of the circular platform notch 32 on the stator mechanism 3 and the output shaft 1. The top 11 of the round table is in contact to realize the clamping process; at the same time, a sinusoidal signal or a square wave signal with equal frequency is input to the two pairs of rotating piezoelectric sheets 34 and the two pairs of clamping piezoelectric sheets 35 respectively, so that the rotating drive action and the clamping action are carried out synchronously , to achieve continuous rotation of the motor.

Further defined technical solutions are as follows:

The cantilever ends of a pair of horizontal arms of the cross-shaped frame 31 are fixedly connected to the two side frame inner walls of the square frame of the base 4 by fixed blocks 37 and bolts respectively; Flexible hinge 36.

Described pretensioning mechanism comprises screw rod 7, nut 6 and spring 5, and spring 5 is sleeved on the screw rod 7; Set on the extended end of the screw rod 7 inside the nut 6; the adjustment of the pre-tightening force is realized by adjusting the nut 6, and the contact or non contact.

A pair of elliptical holes 42 are respectively provided on the horizontal base plates on both sides of the inverted T-shaped groove 41 of the base 4, and positioning screw holes 22 are respectively provided on both sides of the lower part of the support slider 2 corresponding to the pair of elliptical holes 42; 2 is fixed on the base 4 through the threaded connection between the bolt and the positioning threaded hole 22, and a pair of oval holes 42 realize the adjustment of the position of the support slider 2 on the base 4.

The material of the rotating piezoelectric piece 34 and the material of the clamp driving piezoelectric piece 35 are both PZT-4 type piezoelectric ceramic pieces.

The materials of the base 4, the fixed block 37 and the supporting slider 2 are all cast iron.

The material of the flexible hinge 36 is spring steel.

The materials of the cross-shaped frame 31 and the output shaft 1 are carbon structural steel.

Beneficial technical effect of the present invention is embodied in the following aspects:

1. The present invention uses sinusoidal signals to control the driving and clamping action of the stator, so that the contact between the stator and the output shaft is abrupt, and the stator and the mover are driven by static friction without sliding friction. There is no wear between them, prolonging the life of the motor.

2. The working state of the present invention is a resonance state. When two electrical signals work together, the output shaft will realize unidirectional rotation, and the rotation direction of the output shaft can also be reversed by changing the initial phase of the sinusoidal signal. When the operating frequency of the rotary piezoelectric motor is 652Hz and the driving voltage is 180V, the no-load speed and maximum output torque of the rotary piezoelectric motor are 15.6r/min and 83.6N·mm.

Description of drawings

Fig. 1 is a schematic diagram of the structure of the present invention.

Fig. 2 is a rear view of Fig. 1 .

Figure 3 is a schematic diagram of the stator structure.

Figure 4 is a schematic diagram of the mover structure.

Fig. 5 is a schematic diagram of the positional relationship between the stator and the output shaft.

Fig. 6 is a schematic diagram of the base structure.

Fig. 7 is a schematic diagram of the contact and non-contact states of the orifice of the circular table hole on the stator mechanism and the top of the circular table of the output shaft.

Fig. 8 is a diagram of the input signal of the rotationally driven piezoelectric sheet.

Figure 9 is a schematic diagram of the stator rotating action.

Fig. 10 is a diagram of the input signal of the clamp driving piezoelectric film.

Figure 11 is a schematic diagram of the stator clamping action.

Serial numbers in the above picture: output shaft 1, support slider 2, stator mechanism 3, base 4, spring 5, nut 6, screw rod 7, through hole 21, positioning threaded hole 22, cross-shaped frame 31, circular table notch 32, horizontal Arm 33, rotating piezoelectric sheet 34, clamping piezoelectric sheet 35, flexible hinge 36, fixed block 37, vertical arm 38, round table top 11, inverted T-shaped slot 41, oval hole 42, threaded hole 44, through hole 45.

Detailed ways

The present invention will be further described through the embodiments below in conjunction with the accompanying drawings.

Referring to FIG. 1 , a rotary piezoelectric motor includes a base 4 , a stator mechanism 3 and a mover mechanism.

Referring to Fig. 6, the base 4 is an L-shaped base; the horizontal bottom plate of the base 4 has an inverted T-shaped groove 41, and the upright plate of the base 4 is a square frame. A pair of elliptical holes 42 are respectively provided on the horizontal bottom plate on both sides of the inverted T-shaped groove 41; referring to FIG. It is fixed on the base 4 through the threaded connection of the bolt and the positioning threaded hole 22, and a pair of oval holes 42 realize the adjustment of the position of the support slider 2 on the base 4, as shown in FIG. 1 .

Referring to Fig. 3, the stator mechanism 3 includes a cross-shaped frame 31, two pairs of rotating piezoelectric sheets 34 and two pairs of clamping piezoelectric sheets 35; a blind hole is opened in the middle of the cross-shaped frame, and the blind hole is small inside and large outside. Round table notch 32; Two pairs of rotating piezoelectric sheets 34 are respectively fixed on both sides of a pair of vertical arms 38 of the cross-shaped frame to form a drive unit; Two pairs of clamping piezoelectric sheets 35 are respectively fixed on the sides of the cross-shaped frame On both sides of the pair of horizontal arms 33, clamping units are formed. The cantilever ends of a pair of horizontal arms 33 of the cross-shaped frame 31 are fixedly connected to the two side frame inner walls of the square frame of the base 4 by fixed blocks 37 and bolts respectively; flexible hinges are arranged between the cantilever ends of the horizontal arms 33 and the fixed blocks 37 36. The cantilevered ends of a pair of vertical arms 38 do not contact the inner walls of the square frame of the base 4 .

Referring to Fig. 4, the mover mechanism includes an output shaft 1 and a supporting slider 2; the output shaft 1 is installed on the upper part of the supporting slider 2 through a bearing, and one end of the output shaft 1 is a circular platform top 11, and the circular platform top 11 of the output shaft 1 Located in the notch 32 of the round platform of the cross-shaped frame; the lower part of the support slider 2 is arranged on the base 4 in cooperation with the inverted T-shaped groove 41;

Referring to Fig. 1, a pre-tightening mechanism is provided between the upright plate of the base 4 and the supporting slider 2 of the mover mechanism. The pre-tightening mechanism includes a screw rod 7 , a nut 6 and a spring 5 . The screw rod 7 passes through the through hole 43 at the bottom of the base 4 and the through hole 21 at the bottom of the support slider 2, and the spring 5 is set on the extended end of the screw rod 7 inside the nut 6; When adjusting the contact or non-contact between the top 11 of the circular table of the output shaft 1 and the inner wall of the circular table notch 32 of the stator mechanism 3, when the top 11 of the circular table is in contact with the inner wall of the circular table notch 32, see a in Figure 7, the top 11 of the circular table and the inner wall of the circular table notch 32 When the inner walls of the notch 32 are not in contact, see b in FIG. 7 .

The materials of the rotating piezoelectric sheet 34 and the clamping piezoelectric sheet 35 are both PZT-4 piezoelectric ceramic sheets. The materials of the base 4, the fixed block 37 and the supporting slide block 2 are all cast iron. The material of the flexible hinge 36 is spring steel. The material of the cross-shaped frame 31 and the output shaft 1 is carbon structural steel.

The working principle of the present invention is described in detail as follows:

Referring to FIG. 8 , a sinusoidal signal is input to the rotating piezoelectric sheet 34 .

Referring to Fig. 9, when there is no voltage signal, it is shown in a in Fig. 9; the time is from t0 to t1, the vertical arm 38 swings a small angle counterclockwise, as shown in b in Fig. 9, the cross-shaped frame 31 rotates an angle clockwise; When the time is from t1 to t2, the vertical arm 38 returns to the initial position, see c in FIG. In d, the cross-shaped frame 31 rotates an angle counterclockwise; when the time is from t3 to t4, the vertical arm 38 returns to the initial position, as shown in e in FIG. 9 , the cross-shaped frame 31 returns to the initial position.

Referring to FIG. 10 , a sinusoidal signal is input to the clamping piezoelectric sheet 35 .

Referring to Figure 11, the state of the cross-shaped frame 31 when there is no signal is shown as f in Figure 11; when the time is from t0 to t1, the horizontal arm 33 swings toward the direction close to the output shaft 1, see g in Figure 11, and ten The glyph frame 31 is close to the output shaft 1; when the time is from t1 to t2, the horizontal arm 33 returns to the initial position, see h among Fig. 11, while the cross-shaped frame 31 is away from the output shaft 1; when the time is from t2 to t3, the horizontal arm 33 swings away from the output shaft 1, see i in Figure 11, and at the same time the cross-shaped frame 31 moves away from the output shaft 1 again; when the time is from t3 to t4, the horizontal arm 33 swings in a direction close to the output shaft 1, see Figure 11 In j, the cross frame 31 is close to the output shaft 1 at the same time. One cycle is complete.

In one cycle, the vertical arm 38 rotates counterclockwise, at this time the cross-shaped frame 31 rotates clockwise, and the input signal of the clamp piezoelectric sheet 35 makes the cross-shaped frame 31 close to the output shaft 1, at this time, the circular platform groove on the stator mechanism 3 The port 32 is in contact with the apex 11 of the circular platform of the output shaft 1, thereby driving the output shaft 1 to rotate clockwise; when the vertical arm 38 vibrates in the opposite direction, the input signal of the clamp piezoelectric sheet 35 makes the cross-shaped frame 31 away from the output shaft 1; When the vertical arm 38 continues to rotate counterclockwise, the cross-shaped frame 31 continues to approach the output shaft 1, so that the notch 32 of the circular table on the stator mechanism 3 contacts the top 11 of the circular table of the output shaft 1, and so reciprocating, the piezoelectric motor can be realized. Continuous rotation in the clockwise direction. Reverse rotation of the piezoelectric motor can be achieved by reversing the phase angles of the driving and clamping voltage signals. Different speeds and torques can be achieved by adjusting the phase angle and duty cycle of the driving and clamping voltage signals.

Claims (1)

1. A rotary piezoelectric motor, comprising a base (4), a stator mechanism (3) and a mover mechanism, characterized in that: The base (4) is an L-shaped base; an inverted T-shaped groove (41) is opened on the horizontal bottom plate of the base (4), and the upright plate of the base (4) is a square frame; The stator mechanism (3) includes a cross-shaped frame (31), two pairs of rotating piezoelectric sheets (34) and two pairs of clamping piezoelectric sheets (35); a blind hole is opened in the middle of the cross-shaped frame, and the blind hole It is a circular platform notch (32); two pairs of rotating piezoelectric sheets (34) are respectively fixed on the two sides of a pair of vertical arms (38) of the cross-shaped frame to form a drive unit; two pairs of clamping piezoelectric sheets (35 ) are respectively fixed on the two sides of a pair of horizontal arms (33) of the cross-shaped frame to form a clamping unit; the cross-shaped frame (31) is connected to the base (4) The inner wall of the square frame is fixedly connected and fixed in the square frame of the base (4), and the cantilever ends of the pair of vertical arms (38) are not in contact with the inner wall of the square frame of the base (4); The cantilever ends of a pair of horizontal arms of the cross-shaped frame (31) are fixed to the inner walls of the two side frames of the square frame of the base (4) through fixed blocks (37) and bolts respectively; the cantilever ends of the horizontal arms and the fixed A flexible hinge (36) is provided between the blocks (37); A pair of elliptical holes (42) are respectively opened on the horizontal bottom plates on both sides of the inverted T-shaped slot (41) of the base (4), and the two sides of the lower part of the support slider (2) corresponding to the pair of elliptical holes (42) are respectively Positioning threaded holes (22) are provided; the support slider (2) is fixed on the base (4) through the threaded connection between the bolt and the positioning threaded hole (22), and a pair of oval holes (42) realize the support of the slider (2) Adjust the position on the base (4); The materials of the rotating piezoelectric sheet (34) and the clamping piezoelectric sheet (35) are both PZT-4 piezoelectric ceramic sheets; The mover mechanism includes an output shaft (1) and a supporting slider (2); the output shaft (1) is installed on the upper part of the supporting slider (2) through a bearing, and one end of the output shaft (1) is the top of a round platform (11 ), and the top of the round table (11) of the output shaft (1) is located in the round table notch (32) of the cross-shaped frame; the lower part of the support slider (2) is arranged on the base (4) in cooperation with the inverted T-shaped slot (41) superior; A pre-tightening mechanism is provided between the upright plate of the base (4) and the supporting slider (2) of the mover mechanism; The pre-tightening mechanism includes a screw (7), a nut (6) and a spring (5), and the spring (5) is sheathed on the screw (7); the screw (7) passes through the through hole at the bottom of the base (4) (43) and the through hole (21) in the lower part of the support slider (2), the spring (5) is sleeved on the extended end of the screw (7) inside the nut (6); the preload is realized by adjusting the nut (6) The adjustment of the force realizes the contact or non-contact between the top of the circular table (11) of the output shaft (1) and the inner wall of the circular table notch (32) of the stator mechanism (3) during the adjustment work; The materials of the base (4), the fixing block (37) and the supporting slider (2) are all cast iron; The material of the flexible hinge (36) is spring steel; The materials of the cross-shaped frame (31) and the output shaft (1) are carbon structural steel; When working, input sinusoidal signals to two pairs of rotating piezoelectric plates (34), and the elastic vibrators of a pair of vertical arms (38) drive the stator mechanism (3) to achieve forward or reverse rotation alternately in one cycle; The clamping piezoelectric sheet (35) inputs a square wave signal, and the elastic vibrator of a pair of horizontal arms (33) realizes the stator mechanism (3) moving back and forth in the direction perpendicular to the rotation plane within one cycle, realizing the stator mechanism (3) The opening of the notch (32) of the circular platform on the top contacts with the top (11) of the circular platform of the output shaft (1) to realize the clamping process; 35) Input sinusoidal signals or square wave signals with equal frequency respectively, so that the rotation driving action and clamping action are carried out synchronously, so as to realize the continuous rotation of the motor.

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