CN220470173U - Miniature valveless piezoelectric pump - Google Patents

Abstract

The utility model discloses a miniature valveless piezoelectric pump, which relates to the field of piezoelectric pumps, and comprises a frame body and a piezoelectric element positioned outside the frame body, wherein the frame body is provided with an inflow port and an outflow port, the inflow port is a stepped runner formed by superposing a plurality of single structures or a stepped runner or an equal radial runner processed on a single-layer plate, the frame body comprises a top plate assembly, an annular plate assembly and a bottom plate assembly, a cavity formed by clamping the top plate assembly, the annular plate assembly and the bottom plate assembly along the thickness direction forms a pump cavity, and the inflow port and/or the outflow port are positioned on one, two or three of the top plate assembly, the annular plate assembly and the bottom plate assembly. The utility model can obtain the stepped flow passage in a superposition combination mode, can ensure the processing efficiency and reduce the processing difficulty while being maximally close to the gradually deformed reducing flow passage.

Description

Miniature valveless piezoelectric pump

Technical Field

The utility model relates to the field of piezoelectric pumps, in particular to a miniature valveless piezoelectric pump.

Background

The piezoelectric pump is a device for converting electric energy into mechanical energy by using piezoelectric effect, and the piezoelectric ceramic is applied with an alternating current driving signal to make the piezoelectric ceramic generate mechanical vibration with the same frequency as the driving signal, and the mechanical vibration is converted into the movement and flowing effect of fluid, so that the purpose of pumping the fluid is achieved.

Conventional piezoelectric pumps often require the use of one-way valves to control the direction of flow and to limit the reverse flow of fluid. However, check valves tend to have complex, precise mechanical structures and introduce large energy dissipation, which is costly to manufacture, maintain and replace.

The chinese patent of application publication No. CN112832992a discloses a valved hybrid piezoelectric pump, and claim 5 discloses that "the inner wall of the water inlet channel (15) is in an inverted cone shape, and the inner wall of the connection part of the guiding shell (13) and the water outlet (5) is in a cone shape. The scheme is based on the non-uniformity of flow resistance of the fluid in the front and back directions in the conical tube, so that the fluid has a flow difference in the front and back directions in the conical tube, and a unidirectional net flow is generated. The structure omits a one-way stop valve, simplifies the structure and also avoids the pressure loss possibly caused by moving parts.

However, for the existing micro piezoelectric pump, stainless steel, stainless iron and brass thin films with the thickness of 50-600 μm are generally selected as materials of the top plate and the bottom plate, the difficulty of processing cone angles or cone angles for deflection of a central shaft on the materials with the thickness is very large, the processing efficiency is low, the accuracy after processing cannot be ensured, and the processing cost is increased.

Disclosure of Invention

The utility model aims to provide a miniature valveless piezoelectric pump which can obtain a stepped flow passage in a superposition combination mode, is close to a gradually deformed reducing flow passage to the greatest extent, and can ensure the processing efficiency and reduce the processing difficulty.

The aim of the utility model is realized by the following technical scheme:

the miniature valveless piezoelectric pump comprises a frame body and a piezoelectric element positioned outside the frame body, wherein the frame body is provided with an inflow port and an outflow port, the outflow port is a stepped flow passage formed by superposing a plurality of single structures or a stepped through hole formed by processing on a single-layer plate, and the inflow port is a stepped flow passage formed by superposing a plurality of single structures or a stepped through hole formed by processing on the single-layer plate or an equal-diameter through hole serving as a flow passage.

Further, the frame body comprises a top plate assembly, an annular plate assembly and a bottom plate assembly, a cavity formed by clamping the top plate assembly, the annular plate assembly and the bottom plate assembly along the thickness direction forms a pump cavity, and the inflow port and/or the outflow port are/is positioned on one, two or three of the top plate assembly, the annular plate assembly and the bottom plate assembly.

Further, the top plate assembly comprises one or more top plates provided with a first opening;

when the top plate assembly comprises a top plate, a first opening on the top plate is used as an inflow port, and the first opening is an equal-diameter through hole;

when the top plate assembly comprises a plurality of top plates, each layer of top plates are concentric and fixed with each other, the first opening size of each layer of top plates is gradually reduced from the outside of the pump cavity to the inside of the pump cavity, and the inflow opening is formed by superposing a plurality of first openings.

Further, the bottom plate assembly comprises at least two bottom plates, a plurality of bottom plates are concentric and fixed with each other, the bottom plates are provided with second open holes, the second open holes of each layer of bottom plates are gradually reduced from the inside of the pump cavity to the outside of the pump cavity, and the outflow opening is formed by overlapping a plurality of second open holes.

Further, the first opening and the second opening are through holes with equal diameters or through holes with variable diameters, the central axes of the first opening of each layer are mutually overlapped, and the central axes of the second opening of each layer are mutually overlapped.

Further, the central axes of the second openings of each layer are parallel to each other, and the central axes of the second openings and the central axes of the frame body are parallel to each other or not parallel to each other.

Further, the shape of the first openings of each layer is geometrically similar or dissimilar, and the shape of the second openings of each layer is geometrically similar or dissimilar.

Further, the inflow port is located the middle part of bottom plate subassembly, bottom plate subassembly includes bottom plate and installation piece, the middle part of bottom plate is equipped with the mounting hole of stairstepping, the mounting hole includes first hole and second hole, the diameter of first hole be greater than the second hole and with the second hole is concentric, the size of installation piece with the size looks adaptation of mounting hole is fixed in the mounting hole.

Further, the mounting block comprises a first circular plate and a second circular plate, the diameter of the first circular plate is larger than that of the second circular plate, the first circular plate is fixed on the second circular plate and concentric with the second circular plate, the diameter of the first circular plate is identical to that of the first inner hole, the diameter of the second circular plate is identical to that of the second inner hole, a first opening is formed in the edge of the first circular plate, a second opening is formed in the position, corresponding to the first opening, of the edge of the second circular plate, and the outflow opening is formed through the first opening, the second opening, the first inner hole and the second inner hole.

Further, the inflow port is located on the annular plate assembly, the annular plate assembly comprises at least two annular plates, a plurality of annular plates are concentric and fixed with each other, the annular plates are provided with third openings, the size of each layer of third opening of each annular plate is gradually reduced from outside the pump cavity to inside the pump cavity, and the inflow port is formed by superposing a plurality of third openings.

Further, the piezoelectric element is fixed on the top plate assembly, the top plate assembly is composed of a single top plate, the outflow opening is located in the center of the top plate, the outflow opening is an independent stepped hole, the outflow opening gradually reduces from the inside of the pump cavity to the outside of the pump cavity, and a through hole which is not smaller than the diameter of the smallest end of the outflow opening is formed in the position, corresponding to the outflow opening, of the piezoelectric element.

The beneficial effects of the utility model are as follows:

1) The stepped flow channel can be obtained in a superposition combination mode, the stepped flow channel is maximally close to the gradually deformed reducing flow channel, the processing efficiency can be ensured, and the processing difficulty is reduced.

2) The sizes of the first opening and the second opening are subdivided, so that the step surfaces of the adjacent openings are smaller, the inflow opening and the outflow opening can be maximally close to the conical surface of the gradual change type inflow opening, and the flowing effect of fluid in the step-shaped flow passage is ensured.

3) The bottom plate assembly can be arranged into a split structure of a mounting block and a mounting hole, and the mounting hole on the bottom plate can be divided into a plurality of outflow openings through the mounting block.

4) Independent stepped through holes can be formed in a single plate, so that the processing utilization of thick plates is improved, and the problem of inaccurate positioning caused by superposition of multiple layers of plates is solved.

Drawings

FIG. 1 is a schematic view of an inflow port superimposed by two layers of first openings and an outflow port superimposed by two layers of second openings, with the central axes of each layer of first openings coincident and parallel to the central axis of the pump chamber;

FIG. 2 is an exploded view of the structure of FIG. 1;

FIG. 3 is a schematic view of the second openings of each layer having their central axes parallel and not coincident, the central axes of the second openings of each layer being parallel to the central axis of the pump chamber, and the second openings of each layer being aligned along one side for a stacked arrangement;

FIG. 4 is an exploded view of the structure of FIG. 3;

FIG. 5 is a schematic view of the superposition of the inflow opening through three layers of first openings and the outflow opening through three layers of second openings;

FIG. 6 is an exploded view of the structure of FIG. 5;

FIG. 7 is a schematic view of the second openings of each layer having their central axes parallel and not coincident, the central axes of the second openings of each layer being parallel to the central axis of the pump chamber, and the second openings of each layer being stacked in an oblique direction;

FIG. 8 is an exploded view of the structure of FIG. 7;

FIG. 9 is a schematic view of a top plate assembly comprising a single top plate with an independent constant diameter through hole for the inlet;

FIG. 10 is an exploded view of the structure of FIG. 9;

FIG. 11 is a schematic view of a top plate assembly comprising a single top plate, wherein the inlet is an equal diameter through hole in a single top plate, and the second openings in each layer of the outlet are arranged in a staggered and stacked manner along one direction;

FIG. 12 is an exploded view of the structure of FIG. 11;

FIG. 13 is a cross-sectional view of the base plate and mounting block after assembly;

FIG. 14 is a cross-sectional view taken along the line A-A in FIG. 13;

FIG. 15 is a cross-sectional and top view of the mounting block;

FIG. 16 is a cross-sectional view of the base plate of FIG. 13;

FIG. 17 is a schematic view of the inflow opening being formed by stacking the third openings, the outflow opening being located at the center of the top plate;

FIG. 18 is a schematic view of a stepped through hole formed in a single plate, wherein (a) in FIG. 18 is a process of machining a counterbore and then machining the through hole, and (b) in FIG. 18 is a process of machining the through hole and then machining the counterbore;

FIG. 19 is a schematic view of a stepped flow path formed by overlapping tapered holes in a plurality of single plates;

in the figure, 1-flow outlet, 101-second opening, 2-flow inlet, 201-first opening, 202-third opening, 3-bottom plate assembly, 301-bottom plate, 4-top plate assembly, 401-top plate, 5-piezoelectric element, 6-annular plate assembly, 601-annular plate, 7-mounting block, 701-first circular plate, 702-second circular plate, 703-first opening, 704-second opening, 8-mounting hole, 801-first inner hole, 802-second inner hole.

Detailed Description

The technical solutions of the present utility model will be clearly and completely described below with reference to the embodiments, and it is apparent that the described embodiments are only some embodiments of the present utility model, but not all embodiments. All other embodiments, which can be made by a person skilled in the art without any inventive effort, are intended to be within the scope of the present utility model, based on the embodiments of the present utility model.

In the utility model, the piezoelectric element comprises a piezoelectric ceramic plate, the piezoelectric ceramic is adhered to the top plate, and the piezoelectric ceramic and the top plate form a piezoelectric vibrator. The piezoelectric ceramic vibrates in the thickness direction by applying a voltage of a prescribed frequency across the piezoelectric ceramic plate. The annular plate is clamped in the middle through the top plate and the bottom plate, a cylindrical pump cavity is formed, an acoustic Helmholtz resonant cavity is formed in the pump cavity, and when the acoustic resonant frequency of the pump cavity is close to the resonant frequency of the vibrating body, the displacement of the vibrating body can be efficiently converted into the discharge pressure of fluid.

When the fluid being delivered passes through the reduced diameter inlet and outlet ports, a series of flow phenomena may occur, including flow rate changes, pressure changes, energy conversion, and the like. The constricted flow inlet or outlet has a gradual change in size in one direction, transitioning from one port to the other. The flow rate, the flow speed and the pressure of the flow entering the pump cavity from the inflow port can be improved, and the flow rate of the flow exiting the pump cavity from the inflow port can be restrained, so that the net flow of the miniature valveless piezoelectric pump can be increased; the flow rate, the flow speed and the pressure of the pump cavity discharged from the outflow port can be improved by the reduced-diameter outflow port, and the flow rate of the pump cavity discharged from the outflow port can be restrained, and particularly, the miniature piezoelectric pump can discharge high pressure and a large amount of fluid without a one-way valve by the reduced-diameter outflow port with reasonable design structure.

The existing inflow and outflow openings are directly processed into conical holes on a top plate or a bottom plate, but the depth of the processed conical holes is limited due to the thinner thickness of the plate, so that the change range of the cone angle is smaller, and the rectifying phenomenon is not obvious when fluid passes through. Meanwhile, in the machining process, the process for machining the conical holes in the thin plate is complex, the machining difficulty is high, the machining cost is high, and the production yield and the machining precision are difficult to ensure. According to the utility model, the stepped runner can be obtained in a superposition combination mode, the stepped runner is maximally close to the gradually deformed and reduced runner, the processing efficiency can be ensured, the runner forming process is simplified, the processing difficulty is reduced, the production cost is reduced, and the production yield is improved. In one aspect, the stepped flow channel may be formed by stacking multiple layers of carrier plates (top or bottom plates) having first openings, and stacking the carrier plates and the mounting blocks. Alternatively, the stepped flow channels may be formed by stepwise processing on a single carrier plate: firstly, processing a counter bore with larger diameter, then further processing a counter bore with smaller diameter on the basis of the counter bore, repeating the steps until a completely conducted flow channel is formed, or firstly, processing a through hole with smaller diameter, and then further processing the counter bore with larger diameter on the basis of the through hole.

In addition, in order to avoid the restriction of the transport flow rate by the passage capacity of the inflow port, when the sum of the areas of all inflow ports is larger than the sum of the areas of all outflow ports, the restriction of the inflow port to the change of the opening radius can be weakened, and the piezoelectric pump can achieve good performance even if the inflow port is not provided with a stepped reducing opening.

Hereinafter, a plurality of embodiments of the pump according to the present utility model will be described by taking a pump constituting gas delivery as an example. In addition, the pump according to the present utility model can transport a suitable fluid such as a gas-liquid mixture or a liquid, in addition to the gas.

Example 1

Referring to fig. 1-2, in this embodiment, the piezoelectric element 5 is fixed above the top plate 401, and the inflow openings 2 are uniformly arranged along the circumferential direction of the top plate assembly 4, wherein the inflow openings 2 are located between the outer ring of the piezoelectric element 5 and the inner wall of the annular plate assembly 6 (the annular plate assembly 6 only includes a single annular plate in the drawing), and in order to avoid the piezoelectric element 5 from blocking the inflow openings 2 due to unavoidable assembly errors in the assembly process, a distance of 0.05-1 mm needs to be reserved between the edge of the piezoelectric element 5 and the edge of the inflow opening 2 on the top plate 401.

The top plate assembly 4 is formed by superposing two top plates 401, the bottom plate assembly 3 is formed by superposing two bottom plates 301, and the superposition process is fixed by adopting modes of bonding, welding and the like. The top plate 401 is provided with the first openings 201, the positions of the first openings 201 of each layer of the top plate 401 correspond to each other, and meanwhile, the size of each layer of the first openings 201 gradually decreases from outside to inside of the pump cavity, so that the inflow port 2 formed by stacking each layer of the first openings 201 is a stepped flow passage. Meanwhile, the machining difficulty of the single-layer top plate 401 is small, the machining precision is high, conical hole machining is not needed, and only the first openings 201 machined by the single-layer top plates 401 are overlapped, so that the machining efficiency is greatly improved, and the machining difficulty is reduced.

Further, taking one of the inflow openings 2 of the present embodiment as an example, the central axes of the first openings 201 of each layer in the inflow opening 2 are coincident, and meanwhile, the central axes of the first openings 201 of each layer are all parallel to the central axis of the pump cavity, specifically, the first openings 201 of each layer are arranged in a stacked manner along a common axis, and since the size of each layer of the first openings 201 gradually decreases from outside the pump cavity to inside the pump cavity, as shown in fig. 1, the cross-sectional size of the inflow opening 2 is isosceles stepped, so that the inflow opening 2 obtains a flow channel with a vertical geometric central axis in a manner of aligning the centers of the first openings 201, thereby facilitating the fluid outside the pump cavity to be sucked into the pump cavity.

Similarly, in this embodiment, a plurality of outflow openings 1 are uniformly arranged in the middle of the base plate assembly 3, and the base plate assembly 3 also adopts a mode of overlapping two layers of base plates 301, and the outflow openings 1 are formed by corresponding lamination through the second openings 101.

Example 2

Based on the embodiment 1, referring to fig. 3 to 4,

the arrangement of the inflow port 2 in this embodiment is the same as that of embodiment 1, and description thereof will be omitted, and the arrangement of the outflow port 1 is different in that: taking one of the outflow openings 1 as an example, the central axes of the second openings 101 of each layer in the outflow opening 1 are parallel to each other and do not coincide, and at the same time, the central axes of the second openings 101 of each layer are all parallel to the central axis of the pump cavity, specifically, the second openings 101 of each layer are aligned along one side for lamination, and since the size of each layer of the second openings 101 gradually decreases from the inside of the pump cavity to the outside of the pump cavity, as shown in fig. 3, the cross-sectional size of the outflow opening 1 is in a right-angle stepped shape, so that the outflow opening 1 obtains a flow channel with a geometric central axis deflection in a manner that the second openings 101 are aligned along one side, thereby facilitating the fluid in the pump cavity to flow to a designated direction along the angular outflow opening 1.

Example 3

Based on the embodiment 1, referring to fig. 5 to 6,

the arrangement of the inflow port 2 and the outflow port 1 in this embodiment is the same as that of embodiment 1, except that the top plate assembly 4 in this embodiment is stacked by using three layers of top plates 401, and the bottom plate assembly 3 is stacked by using three layers of bottom plates 301, and by subdividing the dimensions of the first opening 201 and the second opening 101, the step surfaces of the adjacent openings are smaller, so that the inflow port 2 and the outflow port 1 can be maximally close to the tapered surfaces of the gradual-change-shaped inflow port 2, and the smaller flow resistance of the fluid in the stepped flow passage is ensured.

Example 4

Based on examples 2-3, as shown in figures 7-8,

the arrangement of the inflow openings 2 in this embodiment is the same as that of embodiment 3, and will not be described in detail, except that the outflow openings 1 in this embodiment are arranged, the plurality of outflow openings 1 are arranged in the middle of the base plate assembly 3, the base plate assembly 3 adopts a form of stacking three layers of base plates 301, and the outflow openings 1 are formed by corresponding stacking through the second openings 101.

Taking one of the outflow openings 1 of the present embodiment as an example, the central axes of the second openings 101 of each layer in the outflow opening 1 are parallel to each other and do not coincide, and at the same time, the central axes of the second openings 101 of each layer are all parallel to the central axis of the pump chamber, specifically, the second openings 101 of each layer are arranged in a stacked manner after being offset along one direction, since the size of the second openings 101 of each layer gradually decreases from the inside of the pump chamber to the outside of the pump chamber, as shown in fig. 7, the cross-sectional size of the outflow opening 1 is in an irregular step shape, so that the outflow opening 1 obtains a flow passage with a geometric central axis offset by the second openings 101 in an inclined arrangement manner, and the outflow opening 1 is different from the outflow opening 1 of the embodiment 2 in that the inclination angle is larger, thereby facilitating the fluid in the pump chamber to flow along the outflow opening 1 with a specific angle to the designated direction.

Example 5

Based on the embodiment 1, referring to fig. 9 to 10,

the arrangement of the outflow port 1 in this embodiment is the same as that of embodiment 1, and will not be described in detail, except that the top plate assembly 4 in this embodiment employs a single top plate 401, and the inflow port 2 is provided as a through hole of equal diameter. Since the sum of the areas of the inflow openings 2 is larger than the sum of the areas of all the outflow openings 1 in order to avoid that the transport flow rate is limited by the throughput of the inflow openings 2, the restriction of the inflow openings 2 can be weakened in this case, and good performance can be obtained even if the inflow openings 2 are provided as through holes of equal diameter.

Example 6

Based on the embodiment 1, referring to fig. 11 to 12,

the inflow port 2 of this embodiment is an equal-diameter through hole on a single top plate, the outflow port 1 of this embodiment is a flow channel with a geometric center axis deflected, and the direction of the fluid in the pump chamber when discharged can be controlled by adjusting the deflection angle of the outflow port 1.

Example 7

Based on the embodiment 1, referring to fig. 13-16 and 18,

the top plate assembly 4 in this embodiment adopts a single top plate 401, the inflow opening 2 is arranged on the top plate 401, the inflow opening 2 is an independent stepped through hole, and specific machining methods are two, one method is to firstly machine a small-diameter through hole on the top plate 401, then machine a large-diameter counter bore on one side of the top plate 401, the counter bore is concentric with the through hole, and the other method is to firstly machine a large-diameter counter bore on the top plate 401, then machine a small-diameter through hole on the basis of the counter bore, and the counter bore is concentric with the through hole. It will be appreciated that for a top plate 401, a bottom plate 301 or an annular plate having a certain thickness (the annular plate assembly 6 in the figure comprises only a single annular plate), a trapezoid hole can be directly formed, and the processing efficiency can be improved compared with the inlet 2 or the outlet 1 formed by lamination, and the waste of the plate material can be reduced.

The bottom plate assembly 3 in this embodiment includes a single bottom plate 301 and a mounting block 7, the middle part of the bottom plate 301 is provided with a stepped mounting hole 8, the mounting hole 8 includes a first inner hole 801 and a second inner hole 802 in the same manner as the flow inlet 2 in this embodiment, the first inner hole 801 has a larger diameter than the second inner hole 802 and is concentric with the second inner hole 802, the mounting block 7 includes a first circular plate 701 and a second circular plate 702, the first circular plate 701 has a larger diameter than the second circular plate 702, the first circular plate 701 is fixed on the second circular plate 702 and is concentric with the second circular plate 702, and since the diameter of the first circular plate 701 is the same as the diameter of the first inner hole 801 and the diameter of the second circular plate 702 is the same as the diameter of the second inner hole 802, the first circular plate 701 is mounted in the first inner hole 801, and the second circular hole is mounted in the second inner hole 802, specifically, the portion of the first circular plate 701 protruding the second circular plate 702 is fixed on the step of the mounting hole 8, and the fixing manner may be by bonding, welding, etc.

The edge of the first circular plate 701 is provided with a first opening 703, the edge of the second circular plate 702 is provided with a second opening 704 corresponding to the position of the first opening 703, and the mounting block 7 is fixed in the mounting hole 8, so that the mounting hole 8 is divided into four flow channels through the first opening 703 and the second opening 704 on the mounting block 7, and meanwhile, the size of the first opening 703 is larger than that of the second opening 704, so that the flow channels which are gradually reduced from the inside of the pump cavity to the outside of the first opening 703 and the second opening 704. In this embodiment, the mounting hole 8 on the base plate 301 can be divided into a plurality of outflow openings 1 by one mounting block 7, and the first opening 703 and the second opening 704 on the mounting block 7 also form a stepped-like flow passage in the vertical direction.

Example 8

On the basis of example 1, as shown in figures 17-18,

the top plate assembly 4 in this embodiment adopts a single top plate 401, the outflow opening 1 is arranged in the center of the top plate 401, the outflow opening 1 is an independent stepped through hole, the diameter of the outflow opening 1 is reduced from the inside of the pump cavity to the outside of the pump cavity, as shown in fig. 18 (b), one method is to firstly process a small-diameter through hole on the top plate 401, then process a large-diameter counter bore on one side of the top plate 401, the counter bore and the through hole are concentric, as shown in fig. 18 (a), and the other method is to firstly process a large-diameter counter bore on the top plate 401, and then process a small-diameter through hole on the basis of the counter bore, the counter bore and the through hole are concentric. At the same time, the center of the piezoelectric element 5 is provided with a corresponding through hole corresponding to the position of the outflow opening 1, and the diameter of the through hole is not smaller than the diameter of the smallest end of the outflow opening 1.

Meanwhile, the annular plate assembly 6 in this embodiment is formed by stacking two annular plates 601, the two annular plates 601 are concentric and fixed to each other, the annular plates 601 are provided with third openings 202, the positions of the third openings 202 of each layer of annular plates 601 correspond to each other, and meanwhile, the size of each layer of third openings 202 is gradually reduced from outside the pump cavity to inside the pump cavity, so that the inflow port 2 formed by stacking each layer of third openings 202 is a stepped flow passage.

It will be appreciated that the openings of the first opening 201, the second opening 101, and the third opening 202 in all the above embodiments are not fixed, and may be circular, square, triangular, etc., so long as the stepped flow path formed by stacking multiple layers of holes is within the protection scope of the present embodiment.

Further, as shown in fig. 19, the first opening 201, the second opening 101, and the third opening 202 in all the above embodiments may be equal-diameter through holes, where the equal-diameter through holes are convenient for machining and shaping; it may be a gradual through hole, such as a tapered hole, and in particular, it is difficult to machine a tapered hole with a certain depth in a thick plate, but by providing a tapered hole with a shallow depth and a small taper angle in each layer of top plate 401, a tapered hole with a certain depth is formed by stacking multiple layers of top plates 401.

The foregoing is merely a preferred embodiment of the utility model, and it is to be understood that the utility model is not limited to the form disclosed herein but is not to be construed as excluding other embodiments, but is capable of numerous other combinations, modifications and environments and is capable of modifications within the scope of the inventive concept, either as taught or as a matter of routine skill or knowledge in the relevant art. And that modifications and variations which do not depart from the spirit and scope of the utility model are intended to be within the scope of the appended claims.

Claims (10)

1. The miniature valveless piezoelectric pump comprises a frame body and a piezoelectric element positioned outside the frame body, wherein the frame body is provided with an inflow port and an outflow port, and the miniature valveless piezoelectric pump is characterized in that: the flow outlet is a stepped flow channel formed by superposing a plurality of single structures or a stepped through hole formed in a single-layer plate, and the flow inlet is a stepped flow channel formed by superposing a plurality of single structures or a stepped through hole formed in a single-layer plate or an equal-diameter through hole.

2. The micro valveless piezoelectric pump according to claim 1, wherein: the frame body comprises a top plate assembly, an annular plate assembly and a bottom plate assembly, wherein a cavity formed by clamping the top plate assembly, the annular plate assembly and the bottom plate assembly in the thickness direction forms a pump cavity, and the inflow port and/or the outflow port are/is positioned on one, two or three of the top plate assembly, the annular plate assembly and the bottom plate assembly.

3. The micro valveless piezoelectric pump according to claim 2, wherein: the top plate assembly comprises one or more top plates, and the top plates are provided with first holes;

when the top plate assembly comprises a top plate, a first opening on the top plate is used as an inflow port, and the first opening is an equal-diameter through hole;

when the top plate assembly comprises a plurality of top plates, each layer of top plates are concentric and fixed with each other, the first opening size of each layer of top plates is gradually reduced from the outside of the pump cavity to the inside of the pump cavity, and the inflow port is formed by superposing a plurality of first openings;

the bottom plate assembly comprises at least two bottom plates, a plurality of the bottom plates are concentric and fixed with each other, the bottom plates are provided with second open holes, the second open holes of each layer of the bottom plates are gradually reduced from the inside of the pump cavity to the outside of the pump cavity, and the outflow opening is formed by overlapping a plurality of the second open holes.

4. A micro valveless piezoelectric pump according to claim 3, wherein: the first open pore and the second open pore are through holes or taper holes with equal diameters, the central axes of the second open pore of each layer are mutually overlapped, and when the top plate component comprises a plurality of layers of top plates, the central axes of the first open pore of each layer are mutually overlapped.

5. A micro valveless piezoelectric pump according to claim 3, wherein: the central axes of the second holes are parallel to each other, and the central axes of the second holes are parallel to the central axis of the frame body.

6. A micro valveless piezoelectric pump according to claim 3, wherein: the shape of each layer of the first open holes is similar or dissimilar geometrically, and the shape of each layer of the second open holes is similar or dissimilar geometrically.

7. The micro valveless piezoelectric pump according to claim 2, wherein: the inflow port is located the middle part of bottom plate subassembly, bottom plate subassembly includes bottom plate and installation piece, the middle part of bottom plate is equipped with the mounting hole of stairstepping, the mounting hole includes first hole and second hole, the diameter of first hole be greater than the second hole and with the second hole is concentric, the size of installation piece with the size looks adaptation of mounting hole is fixed in the mounting hole.

8. The micro valveless piezoelectric pump according to claim 7, wherein: the installation piece includes first plectane and second plectane, the diameter of first plectane is greater than the second plectane, first plectane fix on the second plectane and with the second plectane is concentric, the diameter of first plectane with the diameter of first hole is the same, the diameter of second plectane with the diameter of second hole is the same, be equipped with first opening on the edge of first plectane, the edge of second plectane corresponds the position of first opening is equipped with the second opening, the egress opening passes through first opening, second opening, first hole and second hole jointly form.

9. The micro valveless piezoelectric pump according to claim 2, wherein: the inflow port is located on the annular plate assembly, the annular plate assembly comprises at least two annular plates, the annular plates are concentric and fixed with each other, the annular plates are provided with third openings, the size of each layer of third opening of each annular plate is gradually reduced from outside the pump cavity to inside the pump cavity, and the inflow port is formed by superposing a plurality of third openings.

10. The micro valveless piezoelectric pump according to claim 9, wherein: the piezoelectric element is fixed on the top plate assembly, the top plate assembly consists of a single top plate, the outflow opening is positioned in the center of the top plate, the outflow opening is an independent stepped through hole, the outflow opening gradually reduces from the inside of the pump cavity to the outside of the pump cavity, and a through hole with the smallest diameter not smaller than the outflow opening is arranged at the position of the piezoelectric element corresponding to the outflow opening.