CN108757408A - A kind of Valveless piezoelectric pump - Google Patents

Abstract

The invention provides a valveless piezoelectric pump, which includes an elastic housing, a piezoelectric film layer, an AC power supply and an elastic paddle set, the elastic housing is provided with a hollow pump cavity, and the piezoelectric film layer is attached on the inner wall of the elastic housing, and the piezoelectric film is electrically connected to the AC power supply; the two sides of the pump chamber are respectively connected with flow nozzles communicating with it, and the two flow nozzles are equipped with the The elastic paddle set, the elastic paddle set includes a circular table tube formed by a plurality of elastic paddle units, each of the elastic paddle unit arrays is arranged on the outer wall of the circular table tube, and the inside of the circular table tube is hollow for fluid flow However, the circular platform includes a small-diameter end and a large-diameter end, and the small-diameter ends of the two circular platform tubes face the same direction. The valveless piezoelectric pump adopting the technical solution of the present invention has high pumping efficiency, can realize macroscopic unidirectional fluid flow, and has a flexible structure of the pump body, which has wider application fields.

Description

A valveless piezoelectric pump

technical field

The invention relates to the technical field of piezoelectric pumps, in particular to a valveless piezoelectric pump.

Background technique

Compared with traditional pumps, piezoelectric pumps have the advantages of simple structure, small size, light weight, low energy consumption, no noise, no electromagnetic interference, and can accurately control key parameters such as fluid flow and flow velocity. focus on. At present, there are many applications in the fields of aerospace, biomedicine, machinery, household appliances, microchemical mixing and microelectronic cooling.

The pumping motive force of the piezoelectric pump comes from the deformation generated by the inverse piezoelectric effect of the piezoelectric vibrator. There are many kinds of piezoelectric pumps, but piezoelectric pumps can be divided into piezoelectric pumps with valves and piezoelectric pumps without valves. Generally, the valveless piezoelectric pump has a relatively simple structure. Usually, the design of most piezoelectric pumps starts with the flow channel structure of the inlet and outlet flow pipes. If the coefficients are different, the fluid will form a macroscopic one-way flow. In the prior art, the flow channel can be set in various structures, such as a simple conical flow channel, there are also branch-like flow channels, and there are also flow channels designed in a spiral shape. The principle of its effect is: Brother Earth The forward and reverse flow resistances of the fluid are different under the force.

However, in the prior art, the scheme of changing the flow channel setting is not effective in disturbing the flow. When the fluid passes through the above-mentioned flow channel, the flow disturbance rate of the fluid is low, and only a preliminary one-way flow effect of the fluid is achieved macroscopically, and the fluid in the piezoelectric The pumping efficiency in the pump is low; in addition, the pump body in the prior art is generally provided with piezoelectric sheets in the pump chamber of the rigid pump body, so as to realize the periodic flow of fluid into and out of the pump chamber, but the rigid pressure Electric pumps have their limitations and cannot be used in applications that require the pump body or the entire structure to exhibit flexibility, such as implanting piezoelectric pumps in living organisms.

Contents of the invention

The object of the present invention is to provide a valveless piezoelectric pump, which has high pumping efficiency and can realize macroscopic one-way flow of fluid, and the structure of the pump body is flexible, which has wider application field.

Based on this, the present invention proposes a valveless piezoelectric pump, which includes an elastic housing, a piezoelectric film layer, an AC power supply and an elastic paddle set, the elastic housing is provided with a hollow pump cavity, and the piezoelectric film The layer is attached to the inner wall of the elastic shell, and the piezoelectric film is electrically connected to the AC power supply; the two sides of the pump chamber are respectively connected with flow nozzles communicating with it, and the two flow nozzles are provided with There is the elastic plectrum set, the elastic plectrum set includes a circular platform tube formed by a plurality of elastic plectrum units, each of the elastic plectrum unit arrays is arranged on the outer wall of the circular platform tube, and the inside of the circular platform tube is hollow to For fluid to flow through, the circular platform includes a small-diameter end and a large-diameter end, and the small-diameter ends of the two circular platform tubes face the same direction.

As a preferred solution, each of the elastic pick units is an arc-shaped elastic pick unit, and each of the arc-shaped elastic pick units is bent toward the central axis of the circular table cylinder.

As a preferred solution, it also includes a fixing piece, the middle part of the fixing piece is provided with a first through hole communicating with the pump chamber, the fixing piece is embedded in the nozzle, and the elastic plectrum set A connecting cylinder is provided at the tail, and one end of the connecting cylinder is connected to the large-diameter end of the circular table cylinder, and the connecting cylinder is engaged with the inner wall of the nozzle through the fixing member.

As a preferred solution, the connecting cylinder is provided with a protrusion, the inner wall of the nozzle is provided with a locking groove, and the connecting cylinder is engaged with the locking groove through the protrusion.

As a preferred solution, the elastic shell includes an outer shell and an inner shell, the outer shell, the piezoelectric film layer and the inner shell are stacked in sequence, the inner and outer sides of the piezoelectric film layer have opposite electrodes, the The two electrodes of the piezoelectric film layer are respectively electrically connected to the AC power supply through wires, and both the outer shell and the inner shell are elastic insulating layers.

As a preferred solution, the outer shell and the inner shell are made of silicon rubber.

As a preferred solution, the elastic housing is an elliptical elastic housing, and the shape of the cross section of the pump cavity is elliptical.

As a preferred solution, the two nozzles are respectively located at the endpoints of the long axis of the ellipsoidal elastic shell.

As a preferred solution, both sides of the elastic housing are provided with a second through hole communicating with the pump chamber, and each of the nozzles is interference-fitted in the second through hole, and the nozzles and A soft anti-corrosion sealant is provided at the joint of the elastic shell.

As a preferred solution, when the fluid flows from the small-diameter end of the circular platform to the large-diameter end, the small-diameter end of the circular platform forms a small envelope, and the outer edge of the small envelope is in line with the central axis of the circular platform. An included angle θ is formed, and the value range of the included angle θ is 30°-60°.

Implementing the embodiment of the present invention has the following beneficial effects:

1. The pump body with variable elasticity makes the structure of the pump body flexible, so that the piezoelectric pump has a wider application field, such as implanting the piezoelectric pump into the living body; the elastic paddle set includes multiple elastic paddle units The formed circular table includes a small-diameter end and a large-diameter end. When the fluid flows from the large-diameter end to the small-diameter end inside the circular table, the fluid impacts the elastic paddle unit to expand the small-diameter end of the circular table. There is a lot of fluid passing through, and the flow resistance is small, so it is convenient for the fluid to flow through; when the fluid flows from the small-diameter end to the large-diameter end, the fluid located outside the circular table tube makes the small-diameter end of the circular table tube shrink, and the fluid passing through the unit time is less , and the large flow resistance is not conducive to the flow of fluid; and the small diameter ends of the two cylindrical cylinders are facing the same direction. Based on the above structure, in a working cycle, the two nozzles located on both sides of the pump chamber are respectively recorded as the first nozzle and the second nozzle, at this time, the first nozzle has more fluid flowing in and less fluid flowing out, while the second nozzle has more fluid flowing out and less fluid flowing in, so the fluid macroscopically moves along the second flow in the entire cycle Flow out from the nozzle to the first nozzle, so as to realize the macroscopic one-way flow of the fluid; in addition, compared with the prior art, the elastic paddle group presents a three-dimensional structure, and the elastic paddle group with the above structure has a high disturbance rate for the fluid. In a working cycle, the above-mentioned structure of the elastic paddle set has a high rate of disturbance to the fluid. In a working cycle, when the volume of the pump chamber becomes smaller, more fluid will enter the pump chamber, and when the volume of the pump chamber becomes larger, more fluid will flow into the pump chamber. More fluid flows out of the pump cavity, so that more fluid is pumped in the whole cycle, that is, the piezoelectric pump can pump more fluid in one working cycle, thereby improving the pumping efficiency of the piezoelectric pump.

2. Each elastic paddle unit is an arc-shaped elastic paddle unit, and each arc-shaped elastic paddle unit is bent toward the central axis of the circular table cylinder, so that the bending effect of each arc-shaped elastic paddle unit is better under the impact of fluid , while the arc-shaped elastic paddle unit can recover faster when the fluid impact is lost, and at the same time, the outer wall of the arc-shaped elastic paddle unit has a buffering effect on the fluid, thereby improving the stability of the fluid flow.

3. The piezoelectric pump also includes a fixing piece. The middle part of the fixing piece is provided with a first through hole communicating with the pump cavity. The fixing piece is embedded in the nozzle. One end of the cylinder is connected with the large-diameter end of the round platform tube, and the connecting tube is connected to the inner wall of the nozzle through the fixing piece. The elastic paddle set is installed in the nozzle, which makes the structure easier to disassemble and maintain.

4. The connecting cylinder is provided with a protrusion, and the inner wall of the nozzle is provided with a card slot. The connecting tube is connected to the card slot through the protrusion. inside the mouth.

5. The elastic shell includes an outer shell and an inner shell. The outer shell, the piezoelectric film layer and the inner shell are stacked in sequence. The inner and outer sides of the piezoelectric film layer have opposite electrodes, and the two electrodes of the piezoelectric film layer are respectively connected to the AC through wires. The power supply is electrically connected, and both the outer shell and the inner shell are elastic insulating layers, and a piezoelectric film layer is arranged between the outer shell and the inner shell of the elastic shell, so that the deformation of the piezoelectric film layer can make the entire elastic shell deform, and Both the outer shell and the inner shell are insulating layers, so that the exterior of the entire piezoelectric pump and the interior of the pump chamber are insulating structures, so that the piezoelectric pump can be implanted in a living body and can ensure stable operation.

6. The outer shell and the inner shell are made of silicone rubber. Silicon rubber has good insulation and good elasticity. Silicon rubber is also physiologically inert and does not cause blood coagulation. Therefore, it is widely used in the medical field, which is beneficial to the piezoelectric pump. implanted in the organism.

Description of drawings

FIG. 1 is a schematic structural diagram of a valveless piezoelectric pump in an embodiment of the present invention.

Fig. 2 is a sectional view of a valveless piezoelectric pump in an embodiment of the present invention.

Fig. 3 is a schematic structural view of the nozzle and the fixing part in the embodiment of the present invention.

Fig. 4 is a schematic structural diagram of the elastic paddle set when the fluid flows from the large-diameter end to the small-diameter end in the embodiment of the present invention.

Fig. 5 is a schematic structural diagram of the elastic paddle set when the fluid flows from the small-diameter end to the large-diameter end in the embodiment of the present invention.

In the figure: 1-elastic housing, 2-piezoelectric film layer, 3-AC power supply, 4-elastic paddle group, 5-nozzle, 6-fixing piece, 7-pump chamber; 11-outer shell, 12-inner Shell, 401-round table tube, 402-connecting tube, 403-protrusion, 41-first elastic paddle group, 42-second elastic paddle group, 51-first nozzle, 52-second nozzle; 401a- Small bore end, 401b - large bore end.

Detailed ways

The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some, not all, embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without creative efforts fall within the protection scope of the present invention.

It should be understood that the terms "first", "second", etc. are used in the present invention to describe various information, but these information should not be limited to these terms, and these terms are only used to distinguish information of the same type from each other. For example, "first" information may also be referred to as "second" information without departing from the scope of the present invention, and similarly, "second" information may also be referred to as "first" information.

It should be pointed out that the direction of the arrow in the drawings in this embodiment is the flow direction of the fluid.

As shown in Figures 1 to 5, this embodiment provides a valveless piezoelectric pump, including an elastic housing 1, a piezoelectric film layer 2, an AC power supply 3 and an elastic paddle set 4, the elastic housing 1 is set There is a hollow pump chamber 7, the piezoelectric film layer 2 is attached to the inner wall of the elastic housing 1, and the piezoelectric film is electrically connected to the AC power supply 3, and the AC power supply 3 is the piezoelectric film to improve the cycle When the voltage is changed periodically, the piezoelectric film layer 2 is periodically deformed so that the entire elastic housing 1 is deformed, thereby causing the volume of the pump chamber 7 to achieve periodic changes. It should be pointed out that the pressure in this embodiment The electric thin film layer 1 is composed of a flexible piezoelectric material, specifically, for example, lead zirconate titanate is an inorganic compound, a piezoelectric material, and its chemical formula is Pb[Zr _x Ti _1-x ]O ₃ , where ( 0≤x≤1), also known as PZT, PZT is the main material of electrostrictive actuators at present, the performance of PZT obtained by different x values in the above chemical formula is different, and the same performance will also be affected by the doped materials, pressure Electric materials can realize the direct conversion of electrical energy and mechanical energy. It can not only convert the applied stress into electric charge, but also convert the applied electric field into a linearly related strain. When the Zr/Ti ratio is 52/48 (that is, x=0.52 ), the PZT dielectric constant reaches 3000 at this time, and it belongs to soft PZT, which can be used as the material of the elastically changing piezoelectric film layer 1 in this example. And the pump chamber 7 is in a cycle, when the volume of the pump chamber 7 becomes larger, the fluid located outside the pump chamber 7 is pressed into the pump chamber 7 due to the pressure difference, and the volume of the pump chamber 7 becomes smaller, and the fluid in the pump chamber 7 flows from the pump The cavity 7 is pressed out, that is, the pump cavity 7 realizes the process of fluid inflow to outflow in one cycle. In addition, the elastically variable pump body makes the pump body structure flexible, so that the piezoelectric pump has a wider application field. For example, a piezoelectric pump is implanted in a living body; the two sides of the pump chamber 7 are respectively connected with flow nozzles 5 communicating with it, and the two flow nozzles 5 are all provided with the elastic plectrum group 4, and the elastic plectrum The sheet group 4 includes a circular table tube 401 formed by a plurality of elastic paddle units, and each of the elastic paddle unit arrays is arranged on the outer wall of the circular table tube 401, and the inside of the circular table tube 401 is hollow for fluid to flow through. The cylinder 401 includes a small diameter end 401a and a large diameter end 401b. As shown in FIG. The caliber end 401a expands, and the fluid passing through per unit time is more, and the flow resistance is small so that the fluid flows through; The fluid makes the small-diameter end 401a of the cylindrical cylinder 401 shrink, and the fluid passing per unit time is small, and the large flow resistance is not conducive to fluid flow; and the small-diameter ends 401a of the two cylindrical cylinders 401 face the same direction. In this embodiment, the two nozzles 5 located on both sides of the pump chamber 7 are respectively marked as the first nozzle 51 and the second nozzle 52, and the elastic plectrum group 4 corresponding to the first nozzle 51 is designated as the first nozzle 51. The elastic paddle group 4, the small-diameter end 401a of the first elastic paddle group 4 is set away from the pump chamber 7, the elastic paddle group 4 corresponding to the second nozzle 52 is recorded as the second elastic paddle group 4, the second elastic paddle group 4 The small-diameter end 401a of the paddle set 4 is set toward the pump chamber 7. In a working cycle, when the volume of the pump chamber 7 becomes larger, the external fluid enters the pump chamber 7 from the first nozzle 51 and the second nozzle 52, and the fluid When flowing into the pump chamber 7 from the first nozzle 51, since the small-diameter end 401a of the first elastic paddle group 4 is set away from the pump chamber 7, that is, the fluid flows from the small-diameter end 401a to the large-diameter end 401b, and the fluid is located outside the circular table cylinder 401 The fluid makes the small-diameter end 401a of the cylindrical cylinder 401 shrink, and the fluid passing through the unit time is less, and when the second nozzle 52 flows into the pump chamber 7, the small-diameter end 401a of the second elastic paddle set 4 faces the pump chamber 7 Setting, that is, the fluid flows from the large-diameter end 401b to the small-diameter end 401a in the cylindrical cylinder 401, and the fluid passing through the unit time is more. The second nozzle 52 flows out. At this time, more fluid flows out along the first nozzle 51 per unit time, while less fluid flows out along the second nozzle 52 per unit time. To sum up, in a working cycle, the second nozzle 52 flows in more fluid and flows out less, and the first nozzle 51 flows in more fluid and flows in less, so the fluid macroscopically Flow out along the direction from the second nozzle 52 to the first nozzle 51, so as to realize the macroscopic one-way flow of the fluid. At the same time, since the elastic paddle group 4 presents a three-dimensional structure, compared with the two-dimensional flow channel in the prior art, the elastic paddle group 4 of the above structure has a high disturbance rate for the fluid, and within a working cycle, the pump chamber 7 When the volume becomes smaller, more fluid will enter the pump chamber 7, and when the volume of the pump chamber 7 becomes larger, more fluid will flow out of the pump chamber 7, so that more fluid is pumped in the entire cycle, that is, in a working cycle The piezoelectric pump can pump more fluid, thereby improving the pumping efficiency of the piezoelectric pump. However, in the prior art, a two-dimensional flow channel design is often used on the inlet and outlet flow pipes, which only realizes the macroscopic one-way flow of the fluid, and when the fluid passes through the above-mentioned flow channel, the flow rate of the fluid is low, and the two-dimensional structure The flow resistance of the flow channel is small, so that the difference of the fluid entering and exiting the pump chamber 7 within a unit time is small, and the pumping efficiency of the piezoelectric pump is low. It should be pointed out that the setting form of the first elastic plectrum group 4 in the first nozzle 51 and the second elastic plectrum group 4 in the second nozzle 52 should not be limited to this embodiment, as long as the first elastic plectrum is ensured The direction of the sheet group 4 and the second elastic plectrum group 4 should be the same.

Based on the above technical solution, the pump body with variable elasticity makes the structure of the pump body flexible, so that the piezoelectric pump has a wider application field, such as implanting the piezoelectric pump into the living body; the elastic paddle set 4 includes a plurality of The circular table tube 401 formed by the elastic plectrum unit, the circular table tube 401 includes a small-diameter end 401a and a large-diameter end 401b, when the fluid flows from the large-diameter end 401b to the small-diameter end 401a inside the circular table tube 401, the fluid impacts the elastic plectrum unit so that The small-diameter end 401a of the circular platform tube 401 expands, and the fluid passing through the unit time is large, and the flow resistance is small so that the fluid flows through; The small-diameter end 401a of the circular platform tube 401 shrinks, and the fluid passing through the unit time is small, and the flow resistance is large, which is not conducive to the flow of fluid; and the small-caliber ends 401a of the two circular platform tubes 401 are facing the same direction. In the cycle, the two nozzles 5 located on both sides of the pump chamber 7 are respectively recorded as the first nozzle 51 and the second nozzle 52. At this time, the first nozzle 51 flows in more fluid and flows out less, while the second nozzle 51 More fluid flows out of the nozzle 52, and less fluid flows in, so that the fluid macroscopically flows out along the direction from the second nozzle 52 to the first nozzle 51 in the whole cycle, thereby realizing the macroscopic unidirectional flow of the fluid; in addition, compared to In the prior art, the elastic paddle group 4 presents a three-dimensional structure, and the elastic paddle group 4 of the above-mentioned structure has a high disturbance rate for the fluid, and within a working cycle, the elastic paddle group 4 with the above-mentioned structure has a high disturbance rate for the fluid , in a working cycle, more fluid will enter the pump chamber 7 when the volume of the pump chamber 7 becomes smaller, and more fluid will flow out of the pump chamber 7 when the volume of the pump chamber 7 becomes larger, so that the whole cycle pumps There is more fluid, that is, the piezoelectric pump can pump more fluid in one working cycle, thereby improving the pumping efficiency of the piezoelectric pump.

In this embodiment, each of the elastic paddle units is an arc-shaped elastic paddle unit, and each of the arc-shaped elastic paddle units is bent toward the central axis of the circular table cylinder 401, so that each The bending effect of the arc-shaped elastic paddle unit is better, and the arc-shaped elastic paddle unit can recover faster when the fluid impact is lost. At the same time, the outer wall of the arc-shaped elastic paddle unit has a buffering effect on the fluid, thereby improving the fluid flow. stability.

Wherein, the piezoelectric pump also includes a fixing piece 6. In this embodiment, the fixing piece 6 is a fixing sleeve, and the middle part of the fixing piece 6 is provided with a first through hole communicating with the pump chamber 7, so The fixing part 6 is embedded in the nozzle 5, the tail of the elastic plectrum set 4 is provided with a connecting cylinder 402, one end of the connecting cylinder 402 is connected with the large-diameter end 401b of the circular table cylinder 401, The connecting cylinder 402 is engaged with the inner wall of the nozzle 5 through the fixing member 6. Based on the above structure, the connecting cylinder 402 provided at the tail of the elastic paddle set 4 makes the installation more stable, and the elastic dial is connected through the connecting piece. The sheet group 4 is installed in the nozzle 5, which makes the disassembly and maintenance of the structure more convenient. Specifically, a plurality of elastic paddle units are arranged in an array to form a circular table tube 401 structure, and the large-diameter end 401b of the circular table tube 401 is provided with a connecting ring. In this way, each elastic paddle unit is connected to form a whole, and the connecting cylinder 402 is connected to the large-diameter end 401b of the circular platform tube 401 , thereby forming a complete structure of the elastic paddle set 4 .

Preferably, the connecting cylinder 402 is provided with a protrusion 403, the inner wall of the nozzle 5 is provided with a slot, the connecting cylinder 402 is engaged with the slot through the protrusion 403, and the protrusion 403 The matching structure with the card slot enables the elastic paddle set 4 to be stably and firmly installed in the nozzle 5 .

In addition, the elastic housing 1 includes an outer shell 11 and an inner shell 12, the outer shell 11, the piezoelectric film layer 2 and the inner shell 12 are stacked in sequence, and the inner and outer sides of the piezoelectric film layer 2 have opposite electrodes, the two electrodes of the piezoelectric film layer 2 are electrically connected to the AC power supply 3 through wires respectively, and the outer shell 11 and the inner shell 12 are both elastic insulating layers, and the outer shell of the elastic shell 1 11 and the inner shell 12 are provided with a piezoelectric film layer 2, so that the deformation of the piezoelectric film layer 2 can make the entire elastic shell 1 realize deformation, while the outer shell 11 and the inner shell 12 are insulating layers, thus making the whole The exterior of the piezoelectric pump and the interior of the pump chamber 7 are both insulated structures, so that the piezoelectric pump can be implanted in a living body and can ensure stable operation. Further, the outer shell 11 and the inner shell 12 are made of silicone rubber, which is insulating and has good elasticity. Silicon rubber is also physiologically inert and does not cause blood coagulation, so it is widely used in the medical field , which is beneficial to implant the piezoelectric pump into the living body.

Preferably, the elastic housing 1 is an ellipsoidal elastic housing 1, and the cross-section of the pump chamber 7 is elliptical. The structure of the ellipsoidal elastic housing 1 makes the outer wall of the piezoelectric pump smooth, and the pump chamber 7 The cross-section of 7 is elliptical to ensure that the pump chamber 7 has a large capacity, and when the fluid enters the pump chamber 7, it has a buffering effect after impacting on the elliptical inner wall, so that the pumping of the fluid is more stable. In addition, the two nozzles 5 are respectively located at the endpoints of the long axis of the ellipsoidal elastic housing 1. Based on this, the distance between the two nozzles 5 is the largest in this structure, so that the fluid flows between the two flows. The inflow and outflow of the nozzle 5 will not interfere with each other, so that the pumping of the fluid in the piezoelectric pump is more stable.

Specifically, the two sides of the elastic casing 1 are provided with a second through hole communicating with the pump chamber 7, and each of the nozzles 5 is interference-fitted in the second through hole, and the flow nozzles A soft anti-corrosion sealant is provided at the joint between the nozzle 5 and the elastic housing 1, and the interference installed nozzle 5 makes its installation structure more firm and stable, and the soft anti-corrosion sealant makes the sealing of the nozzle 5 Good, ensure that the fluid flows in and out of the pump chamber 7 through the nozzle 5, and ensure the structural stability of the piezoelectric pump.

In this embodiment, when the fluid flows from the small-diameter end 401a of the cylindrical tube 401 to the large-diameter end 401b, the small-diameter end 401a of the circular platform tube 401 forms a small enveloping circle, and the outer edge of the small enveloping circle is in contact with the large-diameter end 401b. The central axis of the circular platform cylinder 401 forms an included angle θ, and the value range of the included angle θ is 30°-60°. The larger the above-mentioned included angle value, the greater the obstruction of the elastic paddle set 4 to the fluid, namely Less fluid will flow per unit time. On the contrary, the smaller the included angle is, the smaller the obstruction to the fluid will be. normal work. Therefore, the setting of the above included angle can ensure the stable flow path of the fluid, and ensure that each elastic paddle unit can expand and contract multiple times, prolonging the service life of the elastic paddle set 4 . It should be pointed out that, in this embodiment, in the structure of the cylindrical cylinder 401, the ratio of the cross-sectional area of the small-diameter end 401a to the cross-sectional area of the large-diameter end 401b ranges from 1/2- 2/3, based on the above ratio, can ensure the stable operation of the elastic paddle set 4 .

Using the valveless piezoelectric pump of the embodiment of the present invention, the pump body with variable elasticity makes the structure of the pump body flexible, so that the piezoelectric pump has a wider application field, such as implanting the piezoelectric pump in the living body; The paddle group 4 includes a circular table tube 401 formed by a plurality of elastic paddle units, and the circular table tube 401 includes a small diameter end 401a and a large diameter end 401b. When the fluid flows from the large diameter end 401b to the small diameter end 401a inside the circular table tube 401, The impact of the fluid on the elastic paddle unit makes the small-diameter end 401a of the cylindrical tube 401 expand, and the fluid passing through per unit time is more, and the flow resistance is small so that the fluid flows through; and when the fluid flows from the small-diameter end 401a to the large-diameter end 401b, The fluid located outside the cylindrical cylinder 401 makes the small-diameter end 401a of the cylindrical cylinder 401 shrink, and the fluid passing through it per unit time is small, and the large flow resistance is not conducive to the flow of fluid; and the small-diameter ends 401a of the two cylindrical cylinders 401 are facing the same direction, Based on the above structure, in a working cycle, the two nozzles 5 located on both sides of the pump chamber 7 are respectively recorded as the first nozzle 51 and the second nozzle 52. There is less fluid, but the second nozzle 52 has more fluid flowing out and less fluid flowing in, so that the fluid macroscopically flows out along the direction from the second nozzle 52 to the first nozzle 51 in the whole cycle, thereby realizing the macroscopic monotony of the fluid. In addition, compared with the prior art, the elastic paddle group 4 presents a three-dimensional structure, and the elastic paddle group 4 of the above-mentioned structure has a high disturbance rate for the fluid. In one working cycle, the elastic paddle group 4 of the above-mentioned structure For the high disturbance rate of the fluid, in a working cycle, more fluid will enter the pump chamber 7 when the volume of the pump chamber 7 becomes smaller, and more fluid will flow out of the pump chamber 7 when the volume of the pump chamber 7 becomes larger , so that more fluid is pumped in the whole cycle, that is, the piezoelectric pump can pump more fluid in one working cycle, thereby improving the pumping efficiency of the piezoelectric pump.

In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "upper", "lower", "left", "right", "top", "bottom" etc. Orientation or positional relationship is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation of the present invention.

The above is only a preferred embodiment of the present invention, it should be pointed out that for those of ordinary skill in the art, without departing from the technical principle of the present invention, some improvements and replacements can also be made, these improvements and replacements It should also be regarded as the protection scope of the present invention.

Claims (10)

1. A valveless piezoelectric pump, characterized in that: comprise an elastic housing, a piezoelectric film layer, an AC power supply and an elastic paddle group, the elastic housing is provided with a hollow pump cavity, and the piezoelectric film layer Attached to the inner wall of the elastic housing, and the piezoelectric film is electrically connected to the AC power supply; the two sides of the pump chamber are respectively connected with flow nozzles communicating with it, and the two flow nozzles are provided with The elastic plectrum set, the elastic plectrum set includes a circular table tube formed by a plurality of elastic plectrum units, each of the elastic plectrum unit arrays is arranged on the outer wall of the circular table tube, and the inside of the circular table tube is hollow for The fluid flows through, and the circular platform includes a small-diameter end and a large-diameter end, and the small-diameter ends of the two circular platform tubes face the same direction. 2. The valveless piezoelectric pump according to claim 1, characterized in that: each of the elastic paddle units is an arc-shaped elastic paddle unit, and each of the arc-shaped elastic paddle units faces the side of the circular table cylinder. The central axis is curved. 3. The valveless piezoelectric pump according to claim 1, characterized in that: it also includes a fixing piece, the middle part of the fixing piece is provided with a first through hole communicating with the pump chamber, and the fixing piece is embedded Connected in the nozzle, the tail of the elastic plectrum set is provided with a connecting cylinder, one end of the connecting cylinder is connected with the large-diameter end of the circular table cylinder, and the connecting cylinder is connected through the fixing piece. The inner wall of the nozzle is clamped. 4. The valveless piezoelectric pump according to claim 3, characterized in that: the connecting cylinder is provided with a protrusion, the inner wall of the nozzle is provided with a slot, and the connecting cylinder is connected with the protrusion through the protrusion. The card slots are engaged with each other. 5. The valveless piezoelectric pump according to claim 1, characterized in that: the elastic housing includes an outer shell and an inner shell, the outer shell, the piezoelectric film layer and the inner shell are stacked in sequence, the The inner and outer sides of the piezoelectric film layer have opposite electrodes, and the two electrodes of the piezoelectric film layer are respectively electrically connected to the AC power supply through wires, and both the outer shell and the inner shell are elastic insulating layers. 6. The valveless piezoelectric pump according to claim 5, characterized in that: the material of the outer shell and the inner shell is silicon rubber. 7 . The valveless piezoelectric pump according to claim 1 , wherein the elastic housing is an elliptical elastic housing, and the shape of the cross section of the pump cavity is elliptical. 7 . 8 . The valveless piezoelectric pump according to claim 7 , wherein the two nozzles are respectively located at the endpoints of the long axis of the ellipsoidal elastic shell. 9. The valveless piezoelectric pump according to any one of claims 1 to 8, characterized in that: the two sides of the elastic housing are provided with second through holes communicating with the pump chamber, each of the The nozzle is interference-fitted in the second through hole, and a soft anti-corrosion sealant is provided at the joint between the nozzle and the elastic housing. 10. The valveless piezoelectric pump according to any one of claims 1 to 8, wherein when the fluid flows from the small-diameter end of the cylindrical cylinder to the large-diameter end, the small-diameter end of the cylindrical cylinder forms a small packet An enveloping circle, the outer edge of the small enveloping circle forms an included angle θ with the central axis of the circular table tube, and the value range of the included angle θ is 30°-60°.