阅读说明：本技术 一种用于精密液体传输的压电螺杆泵 (Piezoelectric screw pump for precise liquid transmission ) 是由 潘巧生 李英豪 黄梓良 汪权 姜海洋 于 2020-12-14 设计创作，主要内容包括：本发明公开了一种用于精密液体传输的压电螺杆泵,属于压电螺杆泵和流固耦合技术领域。包括螺杆泵和驱动机构。螺杆泵包括通过矩形螺纹间隙配合的螺杆和螺纹管,在螺纹管上设有进口和出口。驱动机构包括在同一平面内的一对压电振子,即水平压电振子和垂直压电振子；水平压电振子和垂直压电振子结构相同,压电振子包括一对位移放大件和压电叠堆,位移放大件为菱形空心框架件,一对位移放大件依次连接,压电叠堆固定设于一个位移放大件内。驱动机构通过柔性铰链连接着环形铰链的外圆周；环形铰链固定套设在螺纹管上。给驱动机构通入正向的正弦信号,通过环形铰链使螺纹管相对于螺杆进行椭圆运动,使螺杆和螺纹管之间的间隙产生变化,实现液体的传输。(The invention discloses a piezoelectric screw pump for precise liquid transmission, and belongs to the technical field of piezoelectric screw pumps and fluid-solid coupling. Comprises a screw pump and a driving mechanism. The screw pump comprises a screw rod and a threaded pipe which are in clearance fit through rectangular threads, and an inlet and an outlet are arranged on the threaded pipe. The driving mechanism comprises a pair of piezoelectric vibrators in the same plane, namely a horizontal piezoelectric vibrator and a vertical piezoelectric vibrator; the horizontal piezoelectric vibrator and the vertical piezoelectric vibrator are identical in structure, each piezoelectric vibrator comprises a pair of displacement amplification pieces and a piezoelectric stack, each displacement amplification piece is a rhombic hollow frame piece, the pair of displacement amplification pieces are sequentially connected, and each piezoelectric stack is fixedly arranged in one displacement amplification piece. The driving mechanism is connected with the outer circumference of the annular hinge through a flexible hinge; the annular hinge is fixedly sleeved on the threaded pipe. The positive sine signal is fed into the driving mechanism, the threaded pipe is enabled to carry out elliptic motion relative to the screw rod through the annular hinge, the gap between the screw rod and the threaded pipe is enabled to change, and liquid transmission is achieved.)

1. The utility model provides a piezoelectric screw pump for transmission of accurate liquid, includes screw pump and actuating mechanism, the screw pump is including cooperation driven screw rod (6) and screwed pipe (7), its characterized in that:

the driving mechanism comprises a pair of piezoelectric vibrators in the same plane, and the pair of piezoelectric vibrators are a horizontal piezoelectric vibrator and a vertical piezoelectric vibrator; the structure of the horizontal piezoelectric vibrator is the same as that of the vertical piezoelectric vibrator, the piezoelectric vibrator comprises a pair of displacement amplification pieces and a piezoelectric stack, the displacement amplification pieces are rhombic hollow frame pieces, and the pair of displacement amplification pieces are connected in sequence; the piezoelectric stack is fixedly arranged in a displacement amplifying piece; the horizontal piezoelectric vibrator and the vertical piezoelectric vibrator are respectively connected with the outer circumference of the annular hinge (8) through flexible hinges; the annular hinge (8) is fixedly sleeved on the threaded pipe (7);

the screw rod (6) is in clearance fit with the threaded pipe (7) through rectangular threads, and the fit end faces at the two ends of the screw rod (6) and the threaded pipe (7) are sealed;

an inlet (71) is formed in the pipe wall of one axial end of the threaded pipe (7), an outlet (72) is formed in the pipe wall of the other axial end of the threaded pipe (7), and an inner port of the inlet (71) and an inner port of the outlet (72) are communicated with the inner pipe wall of the threaded pipe (7) respectively; the two axial end faces of the screw rod (6) and the threaded pipe (7) which are matched are sealed, so that a thread matching gap of the screw rod (6) and the threaded pipe (7), an inlet (71) and an outlet (72) form a sealed gap flow channel (10);

the screw (6) is made of photosensitive resin; the threaded pipe (7) is made of silica gel;

under the longitudinal vibration mode, under the action of sinusoidal signals with the same voltage, the same frequency f and the phase difference of 90 degrees, the horizontal piezoelectric vibrator and the vertical piezoelectric vibrator vibrate to synthesize the vibration of the horizontal piezoelectric vibrator and the vertical piezoelectric vibrator into an annular hinge (8) which drives the threaded pipe (7) to do elliptical motion in a plane and the threaded pipe (7) to do elliptical motion relative to the screw rod (6), so that the transmission of liquid is completed; under the longitudinal vibration mode, under the action of sinusoidal signals with the same voltage, the same frequency f and the phase difference of-90 degrees, the horizontal piezoelectric vibrator and the vertical piezoelectric vibrator vibrate to synthesize the vibration into an annular hinge (8) to drive the reverse elliptical motion of the threaded pipe (7) in a plane and the reverse elliptical motion of the threaded pipe (7) relative to the screw (6), so that the reverse transmission of liquid is completed.

2. A piezoelectric screw pump for precision liquid delivery according to claim 1, wherein: the horizontal piezoelectric vibrator comprises a first horizontal amplifying piece (21), a second horizontal amplifying piece (22) and a horizontal piezoelectric stack (31); the vertical piezoelectric vibrator comprises a first vertical amplifying piece (23), a second vertical amplifying piece (24) and a vertical piezoelectric stack (32); the first horizontal amplifying piece (21), the second horizontal amplifying piece (22), the first vertical amplifying piece (23) and the second vertical amplifying piece (24) are identical in structure and are all diamond-shaped hollow frame pieces.

3. A piezoelectric screw pump for precision liquid delivery according to claim 1, wherein: one diagonal line of the rhombic hollow frame piece is a long diagonal line, and the other diagonal line of the rhombic hollow frame piece is a short diagonal line; the two rhombic hollow frame pieces are sequentially connected in the short diagonal direction, the outer part of one rhombic hollow frame piece in the short diagonal direction is fixedly connected with an annular hinge (8) through a flexible hinge, and the piezoelectric stack is fixed in the long diagonal direction of the other rhombic hollow frame piece.

4. A piezoelectric screw pump for precision liquid delivery according to claim 1, wherein: the diamond-shaped hollow frame piece is made of manganese steel, and the rigidity of the diamond-shaped hollow frame piece in the long diagonal direction is one tenth of that of the piezoelectric stack.

5. A piezoelectric screw pump for precision liquid delivery according to claim 1, wherein: the annular hinge (8) is made of manganese steel, and the included angle between the two flexible hinges on the outer circumference of the annular hinge (8) is 90 degrees; the flexible hinge is of a fillet straight beam type flexible hinge structure, and the flexible hinge has smaller bending rigidity, so that the horizontal piezoelectric vibrator and the vertical piezoelectric vibrator can more easily drive the annular hinge to form elliptical motion in a longitudinal vibration mode.

6. A piezoelectric screw pump for precision liquid delivery according to claim 1, wherein: the Shore hardness of the silica gel material of the threaded pipe (7) is 40 HA.

7. A piezoelectric screw pump for precision liquid delivery according to claim 1, wherein: elongated grooves are formed in two ends of the screw rod (6), and bolts are placed in the elongated grooves and are fixed on the base (1) through the supporting rod (4) and the gasket (5) respectively.

8. A piezoelectric screw pump for precision liquid delivery according to claim 1, wherein: the matching end faces of the two ends of the screw rod (6) and the threaded pipe (7) are sealed by epoxy resin glue (9); the annular hinge (8) is sleeved on the threaded pipe (7) and fixed by epoxy resin glue (9).

9. A piezoelectric screw pump for precision liquid delivery according to claim 1, wherein: the nominal diameter D of the threaded pipe is between 10mm and 30mm, the width D of the rectangular threads of the threaded pipe and the screw is between 0.5mm and 2mm, the fit clearance s is between 0.1 mm and 1mm, and the theoretical output flow Q of the screw pump is approximately equal to pi multiplied by D multiplied by D multiplied by f multiplied by 60 (ml/min).

Technical Field

The invention belongs to the technical field of piezoelectric screw pumps and fluid-solid coupling, and particularly relates to a piezoelectric screw pump for precise liquid transmission.

Background

The structure of the existing piezoelectric screw pump adopts a piezoelectric ceramic piece as a driving device, and the output amplitude of the piezoelectric ceramic piece is small, so that the output power of the piezoelectric screw pump is low; the screw rod and the threaded pipe are in meshing transmission by adopting conical threads, and no fit clearance exists between the screw rod and the threaded pipe. The output flow of the piezoelectric screw pump is completely determined by the output amplitude of the piezoelectric ceramic piece, the output flow of the piezoelectric screw pump cannot be controlled through the structural change of the screw and the threaded pipe, the output flow of the threaded pump cannot be deduced through a theoretical formula, and the precise transmission control of liquid is difficult to realize. There is not fixing device in the project organization, and piezoceramics during operation, screw rod and screwed pipe all can produce the vibration, and the clearance that produces between screw rod and the screwed pipe has uncertainty, leads to the working property unreliability of piezoceramics piece's work efficiency, and piezoceramics piece's work efficiency can not obtain effective utilization.

The traditional screw pump drives a screw rod to work through a motor, most of the traditional screw pump adopts an electromagnetic motor, and the electromagnetic motor is complex in structure and large in size, so that the screw pump is not easy to miniaturize. The electromagnetic motor has no self-locking capability after power failure, so that the traditional screw pump cannot ensure the precision of liquid transmission. The traditional electromagnetic motor can generate electromagnetic pollution, and the traditional screw pump cannot be directly applied to occasions sensitive to electromagnetic interference. Most of the traditional screw pumps have fixed steering, only can pump liquid in a single direction, and cannot realize bidirectional pump output.

Disclosure of Invention

In order to change the output flow of the piezoelectric screw pump through the change of the structure, namely the output flow of the piezoelectric screw pump can be controlled, the invention provides the piezoelectric screw pump for precise liquid transmission.

A piezoelectric screw pump for precise liquid transmission comprises a screw pump and a driving mechanism, wherein the screw pump comprises a screw 6 and a threaded pipe 7 which are in matched transmission;

the driving mechanism comprises a pair of piezoelectric vibrators in the same plane, and the pair of piezoelectric vibrators are a horizontal piezoelectric vibrator and a vertical piezoelectric vibrator; the structure of the horizontal piezoelectric vibrator is the same as that of the vertical piezoelectric vibrator, the piezoelectric vibrator comprises a pair of displacement amplification pieces and a piezoelectric stack, the displacement amplification pieces are rhombic hollow frame pieces, and the pair of displacement amplification pieces are connected in sequence; the piezoelectric stack is fixedly arranged in a displacement amplifying piece; the horizontal piezoelectric vibrator and the vertical piezoelectric vibrator are respectively connected with the outer circumference of the annular hinge 8 through flexible hinges; the annular hinge 8 is fixedly sleeved on the threaded pipe 7 by using epoxy resin glue 9;

the screw rod 6 and the threaded pipe 7 are in clearance fit of rectangular threads, and the fit end faces of the two ends of the screw rod 6 and the threaded pipe 7 are sealed by epoxy resin glue 9;

an inlet 71 is formed in the pipe wall of one axial end of the threaded pipe 7, an outlet 72 is formed in the pipe wall of the other axial end of the threaded pipe 7, and an inner port of the inlet 71 and an inner port of the outlet 72 are respectively communicated with the inner pipe wall of the threaded pipe 7; the two axial end faces of the screw 6 and the threaded pipe 6 which are matched are sealed, so that a thread matching gap of the screw 6 and the threaded pipe 7, an inlet 71 and an outlet 72 form a sealed gap flow passage 10;

the screw 6 is made of photosensitive resin; the threaded pipe 7 is made of silica gel;

under the longitudinal vibration mode, under the action of sinusoidal signals with the same voltage, the same frequency f and the phase difference of 90 degrees, the horizontal piezoelectric vibrator and the vertical piezoelectric vibrator vibrate to synthesize the vibration of the horizontal piezoelectric vibrator and the vertical piezoelectric vibrator into an annular hinge 8 which drives the threaded pipe 7 to do elliptical motion in a plane and the threaded pipe 7 to do elliptical motion relative to the screw 6, so that the liquid transmission is completed; under the longitudinal vibration mode, under the action of sinusoidal signals with the same voltage, the same frequency f and the phase difference of-90 degrees, the horizontal piezoelectric vibrator and the vertical piezoelectric vibrator vibrate to synthesize the vibration of the horizontal piezoelectric vibrator and the vertical piezoelectric vibrator into an annular hinge 8 to drive the reverse elliptical motion of the threaded pipe 7 in a plane and the reverse elliptical motion of the threaded pipe 7 relative to the screw 6, so that the reverse transmission of liquid is completed.

The technical scheme for further limiting is as follows:

the horizontal piezoelectric vibrator comprises a first horizontal amplifying piece 21, a second horizontal amplifying piece 22 and a horizontal piezoelectric stack 31; the vertical piezoelectric vibrator comprises a first vertical amplifying piece 23, a second vertical amplifying piece 24 and a vertical piezoelectric stack 32; the first horizontal amplifying element 21, the second horizontal amplifying element 22, the first vertical amplifying element 23 and the second vertical amplifying element 24 are identical in structure and are all diamond-shaped hollow frame elements.

One diagonal line of the rhombic hollow frame piece is a long diagonal line, and the other diagonal line of the rhombic hollow frame piece is a short diagonal line; the two rhombic hollow frame pieces are sequentially connected in the short diagonal direction; the piezoelectric stack is fixed on the long diagonal direction of one rhombic hollow frame piece, and the outer part of the other rhombic hollow frame piece in the short diagonal direction is fixedly connected with a ring-shaped hinge 8 through a flexible hinge.

The diamond-shaped hollow frame piece is made of manganese steel, and the rigidity of the diamond-shaped hollow frame piece in the long diagonal direction is one tenth of that of the piezoelectric stack.

The annular hinge 8 is made of manganese steel, and the included angle between the two flexible hinges on the outer circumference of the annular hinge 8 is 90 degrees; the flexible hinge is of a fillet straight beam type flexible hinge structure, and the flexible hinge has smaller bending rigidity, so that the horizontal piezoelectric vibrator and the vertical piezoelectric vibrator can more easily drive the annular hinge to form elliptical motion in a longitudinal vibration mode.

The Shore hardness of the silica gel of the material of the threaded pipe 7 is 40 HA.

Two ends of the screw rod 6 are provided with elongated slots, and bolts are placed in the elongated slots and are fixed on the base 1 through the support rod 4 and the gasket 5 respectively.

The matching end faces of the two ends of the screw 6 and the threaded pipe 7 are sealed by epoxy resin glue 9; the annular hinge 8 is sleeved on the threaded pipe 7 and fixed by epoxy resin glue.

The nominal diameter D of the threaded pipe is between 10mm and 30mm, the width D of the rectangular threads of the threaded pipe and the screw is between 0.5mm and 2mm, the fit clearance s is between 0.1 mm and 1mm, and the theoretical output flow Q of the screw pump is approximately equal to pi multiplied by D multiplied by D multiplied by f multiplied by 60 (ml/min).

Compared with the prior art, the beneficial technical effects of the invention are embodied in the following aspects:

1. the invention deduces the theoretical output flow through a formula, and can adjust the output flow of the piezoelectric screw pump according to the change of the structure.

The output flow of the piezoelectric screw pump provided by the invention is in direct proportion to the nominal diameter D of a threaded pipe, the width D of a rectangular thread and the fit clearance s of the thread.

The volume V of the extruded screw pipe per rotation is approximately equal to pi multiplied by D multiplied by s multiplied by D

Number of turns of rotation of threaded pipe per minute X = f × 60

The flow rate of the threaded pipe per minute is Q = V multiplied by X ≈ pi multiplied by D multiplied by D multiplied by f multiplied by 60

The piezoelectric screw pumps with different output flow Q grades are formed by designing different rectangular thread widths d and thread fit gaps s, and the output flow of the piezoelectric screw pumps can be adjusted by adjusting the driving signal frequency f, so that the output flow of the piezoelectric screw pumps can be in a larger range, and therefore the piezoelectric screw pumps provided by the invention can be applied to occasions with different flow requirements. The screw pump in the prior art cannot calculate the theoretical flow, so that the output flow cannot be accurately controlled.

2. The screw pump of the invention has larger flow than the existing screw pump. The driving device of the invention is a piezoelectric vibrator consisting of a piezoelectric stack and a displacement amplifying part, has large output amplitude, and improves the integral output performance of the piezoelectric screw pump. The nominal diameter of the thread of the existing piezoelectric screw pump is 12mm, the width of the thread is 1mm, the output flow under the frequency of a driving signal 800V and the frequency of 13.8kHz is 0.75ml/min, the nominal diameter of the thread of the piezoelectric screw pump provided by the invention is 12mm, the width of the thread is 1.5mm, the fit clearance is 0.5mm, the flow under the frequency of a driving signal 400V and the frequency of 200Hz is 10ml/min, and the output performance of the piezoelectric screw pump is effectively improved.

3. The screw pipe is provided with the inlet and the outlet, the screw thread fit clearance between the screw rod and the screw pipe, and the inlet and the outlet form a sealed clearance flow channel which is directly connected with the material pipe for liquid transmission, so that the liquid transmission is more convenient. The existing piezoelectric screw pump is not provided with a water inlet and a water outlet, and cannot be directly connected with a material pipe for liquid transmission.

Drawings

FIG. 1 is a schematic diagram of the present invention.

Fig. 2 is a schematic structural view of the drive mechanism.

FIG. 3 is an assembly view of the ring hinge and threaded pipe.

Fig. 4 is a schematic view of a screw structure.

Fig. 5 is a cross-sectional view of a threaded pipe.

FIG. 6 is a cross-sectional view of the screw and threaded tube in combination.

Fig. 7 is a partially enlarged view of fig. 6.

Fig. 8 is a schematic diagram of the operation of the piezoelectric vibrator and the ring hinge.

Fig. 9 is a working principle diagram of a screw and a threaded pipe.

Fig. 10 is a driving signal diagram.

Fig. 11 is a schematic structural diagram of a conventional piezoelectric screw pump.

Numbers in fig. 1-8: the device comprises a base 1, a first horizontal displacement amplifying piece 21, a second horizontal displacement amplifying piece 22, a first vertical displacement amplifying piece 23, a second vertical displacement amplifying piece 24, a horizontal piezoelectric stack 31, a vertical piezoelectric stack 32, a support rod 4, a gasket 5, a screw rod 6, a threaded pipe 7, an inlet 71, an outlet 72, an annular hinge 8, epoxy resin glue 9 and a clearance flow channel 10.

Detailed Description

The technical solution of the present invention is further described in detail by embodiments with reference to the accompanying drawings.

The present invention may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.

Referring to fig. 1, a piezoelectric screw pump for precision liquid delivery includes a screw pump and a drive mechanism.

The screw pump comprises a screw 6 and a threaded pipe 7 which are in matched transmission. The screw 6 is made of photosensitive resin, and two ends of the screw 6 are designed with elongated slots and are fixed on the base 1 through a support rod 4 and a gasket 5 respectively, as shown in fig. 4 and fig. 1. The material of the threaded pipe 7 is silica gel, and the shore hardness is 40HA, see fig. 5. The screw rod 6 and the threaded pipe 7 are in clearance fit of rectangular threads, the nominal diameter of the threads is D, the width of the rectangular threads is D, and the fit clearance of the rectangular threads is s, which is shown in figures 6 and 7. An inlet 71 is formed in the pipe wall of one axial end of the threaded pipe 7, an outlet 72 is formed in the pipe wall of the other axial end of the threaded pipe 7, and an inner port of the inlet 71 and an inner port of the outlet 72 are respectively communicated with the inner pipe wall of the threaded pipe 7. Referring to fig. 6, the two axial end faces of the screw rod 6 and the threaded pipe 7 are sealed by epoxy resin glue 9, so that the thread fit clearance of the screw rod 6 and the threaded pipe 7, the inlet 71 and the outlet 72 form a sealed clearance flow passage 10.

Referring to fig. 2, the driving mechanism includes a pair of piezoelectric vibrators in the same plane, the pair of piezoelectric vibrators are a horizontal piezoelectric vibrator and a vertical piezoelectric vibrator, and the horizontal piezoelectric vibrator and the vertical piezoelectric vibrator have the same structure. The horizontal piezoelectric vibrator includes a first horizontal amplification piece 21, a second horizontal amplification piece 22, and a horizontal piezoelectric stack 31; the vertical piezoelectric vibrator includes a first vertical amplifying piece 23, a second vertical amplifying piece 24, and a vertical piezoelectric stack 32.

The first horizontal amplifying element 21, the second horizontal amplifying element 22, the first vertical amplifying element 23 and the second vertical amplifying element 24 are identical in structure and are all diamond-shaped hollow frame elements, the diamond-shaped hollow frame elements are made of manganese steel, and the rigidity of the diamond-shaped hollow frame elements in the long diagonal direction is one tenth of that of the piezoelectric stack.

Referring to fig. 2 and 3, one diagonal line of the diamond-shaped hollow frame member is a long diagonal line, and the other diagonal line is a short diagonal line; the two rhombic hollow frame pieces are sequentially connected in the short diagonal direction; the short diagonal direction outer part of one rhombic hollow frame piece is fixedly connected to the base 1, the short diagonal direction outer part of the other rhombic hollow frame piece is fixedly connected to the annular hinge 8 through the flexible hinge, and the annular hinge 8 is fixedly sleeved on the threaded pipe 7 and fixed through epoxy resin glue. The horizontal piezoelectric stack 31 is fixedly mounted in the long diagonal direction of the first horizontal amplifying element 21 connected to the base, and the vertical piezoelectric stack 32 is fixedly mounted in the long diagonal direction of the first vertical amplifying element 23 connected to the base.

The material of the annular hinge 8 is manganese steel, referring to fig. 3, the included angle between two flexible hinges on the outer circumference of the annular hinge 8 is 90 degrees, the flexible hinges are fillet straight beam type flexible hinges, and the flexible hinges have smaller bending rigidity, so that the horizontal piezoelectric vibrator and the vertical piezoelectric vibrator can drive the annular hinge to form elliptical motion more easily in a longitudinal vibration mode.

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

in the specific implementation process, sinusoidal signals with the same voltage amplitude, the same frequency and 90-degree phase difference are respectively introduced into the horizontal piezoelectric stack 31 and the vertical piezoelectric stack 32; as shown in fig. 10, the signal a is input to the horizontal piezoelectric stack 31, the signal B is input to the vertical piezoelectric stack 32, the piezoelectric amplitudes of the two sets of signals are V, the frequency is f, and the driving signal a leads the driving signal B by 90 °.

When no driving signal is input into each of the horizontal piezoelectric stack 31 and the vertical piezoelectric stack 32, the positions of the piezoelectric stacks are kept unchanged, the positions of the first horizontal amplifying part 21, the second horizontal amplifying part 22, the first vertical amplifying part 23 and the second vertical amplifying part 24 are kept unchanged, the position of the ring hinge 8 is kept unchanged, as shown in (a) of fig. 8, the positions of the screw 6 and the threaded pipe 7 are kept unchanged, and the clearance flow passage 10 is kept in an initial state, as shown in (a) of fig. 9.

When the driving signals are input to the horizontal piezoelectric stack 31 and the vertical piezoelectric stack 32 at time t0, the driving signal a is a positive voltage, the piezoelectric amplitude V, the horizontal piezoelectric stack 31 expands in the X-axis direction, and the first horizontal amplifying element 21 and the second horizontal amplifying element 22 expand in the X-axis direction and contract in the Y-axis direction. The voltage of the driving signal B is 0, the position of the vertical piezoelectric stack 32 is kept unchanged, and the positions of the first vertical amplifying element 23 and the second vertical amplifying element 24 are kept unchanged. The ring hinge 8 is moved in the negative Y-axis direction with respect to the initial position, as shown in fig. 8 (d). The ring hinge 8 drives the threaded pipe 7 to move in the negative Y-axis direction, as shown in fig. 9 (d).

When the horizontal piezoelectric stack 31 and the vertical piezoelectric stack 32 are supplied with the driving signal at the time t1, the voltage of the driving signal a is 0, the position of the horizontal piezoelectric stack 31 remains unchanged, and the positions of the first horizontal amplifying element 21 and the second horizontal amplifying element 22 remain unchanged. The driving signal B is a positive voltage, the piezoelectric amplitude V, the vertical piezoelectric stack 32 expands in the Y-axis direction, and the first vertical amplifying element 23 and the second vertical amplifying element 24 expand in the Y-axis direction and contract in the X-axis direction. The ring hinge 8 is moved in the negative X-axis direction with respect to the initial position, as shown in fig. 8 (e). The ring hinge 8 drives the threaded pipe 7 to move in the negative X-axis direction, as shown in fig. 9 (e).

When the horizontal piezoelectric stack 31 and the vertical piezoelectric stack 32 are supplied with the driving signal at time t2, the voltage of the driving signal a is a negative voltage, the piezoelectric amplitude is V, the horizontal piezoelectric stack 31 contracts in the X-axis direction, and the first horizontal amplifying element 21 and the second horizontal amplifying element 22 contract in the X-axis direction and expand in the Y-axis direction. The voltage of the driving signal B is 0, the position of the vertical piezoelectric stack 32 is kept unchanged, and the positions of the first vertical amplifying element 23 and the second vertical amplifying element 24 are kept unchanged. The ring hinge 8 is moved in the positive Y-axis direction with respect to the initial position, as shown in fig. 8 (b). The ring hinge 8 drives the threaded pipe 7 to move in the positive Y-axis direction, as shown in fig. 9 (b).

When the horizontal piezoelectric stack 31 and the vertical piezoelectric stack 32 are supplied with the driving signal at the time t3, the voltage of the driving signal a is 0, the position of the horizontal piezoelectric stack 31 remains unchanged, and the positions of the first horizontal displacement amplification piece 21 and the second horizontal displacement amplification piece 22 remain unchanged. The voltage of the driving signal B is a negative voltage, the piezoelectric amplitude is V, the vertical piezoelectric stack 32 contracts in the Y-axis direction, and the first vertical displacement amplifier 23 and the second vertical displacement amplifier 24 contract in the Y-axis direction and expand in the X-axis direction. The ring hinge 8 is moved in the positive X-axis direction with respect to the initial position, as shown in fig. 8 (c). The ring hinge 8 drives the threaded pipe 7 to move in the positive X-axis direction, as shown in fig. 9 (c).

When the horizontal piezoelectric stack 31 and the vertical piezoelectric stack 32 are supplied with the driving signal at the time t4, the driving signal coincides with the time t 0. The driving signal a is a positive voltage, the piezoelectric amplitude V, the horizontal piezoelectric stack 31 expands in the X-axis direction, and the first horizontal amplifying element 21 and the second horizontal amplifying element 22 expand in the X-axis direction and contract in the Y-axis direction. The voltage of the driving signal B is 0, the position of the vertical piezoelectric stack 32 is kept unchanged, and the positions of the first vertical amplifying element 23 and the second vertical amplifying element 24 are kept unchanged. The ring hinge 8 is moved in the negative Y-axis direction with respect to the initial position, as shown in fig. 8 (d). The ring hinge 8 drives the threaded pipe 7 to move in the negative Y-axis direction, as shown in fig. 9 (d).

When the driving signal is cycled at t0-t1-t2-t3-t4, as shown in FIG. 10. The positions of the horizontal piezoelectric stack 31 and the vertical piezoelectric stack 32 and the first horizontal magnifying member 21, the second horizontal magnifying member 22, the first vertical magnifying member 23, and the second vertical magnifying member 24 are cyclically moved in (d) - (e) - (b) - (c) - (d), as shown in fig. 8. The positions of the screw 6 and the threaded pipe 7 are cyclically moved in (d) - (e) - (b) - (c) - (d), as shown in fig. 9.

When the relative positions of the screw 6 and the threaded pipe 7 are in the circulating motion of (d) - (e) - (b) - (c) - (d), liquid is extruded in the clearance flow channel and is extruded from the water inlet 71 of the threaded pipe 7 to the water outlet 72, when the driving signal is in the circulating operation of t0-t1-t2-t3-t4, the liquid is extruded from the water inlet to the water outlet all the time, and the piezoelectric screw pump works normally.

When the driving signal is turned off when the piezoelectric screw pump operates, the piezoelectric vibrator stops operating, the position of the piezoelectric stack is kept unchanged, the positions of the first horizontal amplifying part 21, the second horizontal amplifying part 22, the first vertical amplifying part 23 and the second vertical amplifying part 24 are kept unchanged, the position of the ring hinge 8 is kept unchanged, as shown in (a) of fig. 8, the positions of the screw 6 and the threaded pipe 7 are kept unchanged, and the clearance flow passage 10 is kept in an initial state, as shown in (a) of fig. 9. The threaded pipe does not extrude liquid any more, and the liquid in the gap flow channel 10 is not transmitted any more, so that the precise liquid transmission control is realized.

In a specific embodiment, a screw and a threaded tube are used, the threaded tube having a nominal diameter D of 12mm, a thread width D of 1mm, a fit clearance s of 0.3mm, and a flow rate of 2.8ml/min at a frequency of 210Hz of a drive signal of 400V.

In a specific embodiment, a screw and a threaded tube are used, the threaded tube having a nominal diameter D of 12mm, a thread width D of 1.5mm, a fit clearance s of 0.3mm, and a flow rate of 6.6ml/min at a frequency of 215Hz at 400V of the drive signal.

In a specific embodiment, a screw and a threaded tube are used, the threaded tube having a nominal diameter D of 12mm, a thread width D of 1.5mm, a fit clearance s of 0.5mm, and a flow rate of 10ml/min at a frequency of 200Hz at a drive signal of 400V.

In a specific embodiment, a screw and a threaded tube are used, the nominal diameter D of the threaded tube being 24mm, the thread width D being 1.5mm, the fit-up clearance s being 0.5mm, and the flow rate at a frequency of 400V of the drive signal and 205Hz being 15.4 ml/min.

The screw 6 and the threaded pipe 7 with different nominal diameters D, thread widths D and fit clearances s are assembled in the annular hinge 8 to form piezoelectric screw pumps with different output flow grades, and the output flow of the piezoelectric screw pumps can be adjusted by adjusting the frequency f of the driving signal, so that the output flow of the piezoelectric screw pumps can be in a larger range, and the piezoelectric screw pumps provided by the invention can be applied to occasions with different flow requirements.

It will be understood by those skilled in the art that, unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the prior art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein. The above-mentioned embodiments, objects, technical solutions and advantages of the present invention are further described in detail, it should be understood that the above-mentioned embodiments are only illustrative of the present invention and are not intended to limit the present invention, and any modifications, equivalents, improvements and the like made within the spirit and principle of the present invention should be included in the protection scope of the present invention.