Fluid actuator, piezoelectric pump and axial superposition pump

Abstract

The fluid actuator comprises piezoelectric ceramic, a through hole is formed in the center of the piezoelectric ceramic in a penetrating mode, two electrodes are arranged on the piezoelectric ceramic, and wiring terminals of the two electrodes are located on the same side; the flexible electric connection sheet is pasted on the piezoelectric ceramic and electrically connected with the wiring terminals of the two electrodes, and the flexible electric connection sheet is connected with the piezoelectric ceramic and then located on the outer side of the piezoelectric ceramic to form a peripheral flexible area; the deformation steel sheet is adhered to the surface, far away from the piezoelectric ceramic, of the flexible electric connection sheet; or the deformed steel sheet is adhered to the surface, far away from the flexible electric connection sheet, of the piezoelectric ceramic; the communication channel is formed in any position, except the center, of the actuator in a penetrating mode, so that the two spaces located above and below the actuator are communicated; the piezoelectric pump comprises a pump shell and the fluid brake. An axial superposition pump is formed by superposing at least two piezoelectric pumps in the axial direction. The device is simple in structure, the using effect is improved, and the device has high application and popularization value.

Description

Technical Field

[0001] The present invention relates to the field of actuators and piezoelectric pumps, and in particular to a fluid actuator, a piezoelectric pump and an axial superposition pump. Background Art

[0002] Piezoelectric pumps are generally used in some portable electronic devices, such as some portable blood pressure monitors, head-mounted massagers, etc. They are relatively small pumps used to deliver positive pressure or provide vacuum. In order to achieve the desired goals of small size, high efficiency and silent operation, such pumps must operate at very high frequencies, usually around 20kHz or higher. In order to operate at high frequencies, the valves equipped with the pump must respond to high-frequency oscillating pressure, which can be rectified to produce a net fluid flow through the pump.

[0003] An actuator is configured in the piezoelectric pump, and the periodic vibration of the actuator is used to achieve fluid transmission. However, the fluid actuator used in the piezoelectric pumps currently on the market has disadvantages such as limited movement range, which affects the fluid transmission effect, resulting in poor use of the piezoelectric pump. In addition, the piezoelectric pump structure of the prior art has relatively more external pipelines, which cannot well achieve flexible superposition of the pumps, and there are many inconveniences in actual use. Therefore, the present invention proposes a fluid actuator, a piezoelectric pump, and an axial superposition pump to solve some technical problems of the prior art. Summary of the invention

[0004] The object of the present invention is to provide a fluid actuator, a piezoelectric pump and an axial superposition pump to solve some problems existing in the prior art.

[0005] To achieve the above object, the present invention adopts the following technical solution:

[0006] A fluid actuator comprises: a piezoelectric ceramic, a through hole is formed through the center of the piezoelectric ceramic, two electrodes are arranged on the piezoelectric ceramic, the two electrodes have opposite polarities and are respectively arranged on the upper and lower surfaces of the piezoelectric ceramic, one of the electrodes is bent along the side of the piezoelectric ceramic and extends to the other surface, so that the wiring terminals of the two electrodes are located on the same side; a flexible electrical connecting sheet, the flexible electrical connecting sheet is pasted on the piezoelectric ceramic and electrically connected to the wiring terminals of the two electrodes to form a loop, and after the flexible electrical connecting sheet is connected to the piezoelectric ceramic, it is located on the outside of the piezoelectric ceramic to form an outer flexible area; a deformable steel sheet, the deformable steel sheet is bonded to the surface of the flexible electrical connecting sheet away from the piezoelectric ceramic; or the deformable steel sheet is bonded to the surface of the piezoelectric ceramic away from the flexible electrical connecting sheet; a connecting channel, the connecting channel is opened through any position of the actuator except the center, so that the two spaces located above and below the actuator are connected.

[0007] Furthermore, the communication channel sequentially passes through the piezoelectric ceramic, the flexible electrical connection sheet and the deformable steel sheet.

[0008] Furthermore, the communication channel is opened through the peripheral flexible area.

[0009] Furthermore, the flexible electrical connection sheet is formed by pressing a resin material and an ultra-thin conductive copper sheet.

[0010] Furthermore, a glue hole is provided through the bonding area between the flexible electrical connection sheet and the piezoelectric ceramic or the deformed steel sheet.

[0011] A piezoelectric pump comprises a pump housing and any one of the fluid brakes described above, wherein the fluid actuator is installed inside the pump housing to divide the internal space of the pump housing into two upper and lower pump chambers, and the upper and lower parts of the pump housing are respectively penetrated by a positive-pressure fluid outlet and a negative-pressure fluid inlet, and a one-way valve is respectively installed on the positive-pressure fluid outlet and the negative-pressure fluid inlet.

[0012] Furthermore, the two one-way valves are both closed when the fluid actuator moves toward the negative-pressure fluid suction port side; and the two one-way valves are both opened when the fluid actuator moves toward the positive-pressure fluid outlet side.

[0013] Furthermore, a filter mesh is fixedly installed on the outside of the negative pressure fluid suction port.

[0014] An axially stacked pump is formed by axially stacking at least two piezoelectric pumps as described above. When two adjacent piezoelectric pumps are connected, the positive pressure fluid outlet of one piezoelectric pump is connected to the negative pressure fluid intake port of another piezoelectric pump to form a fluid passage.

[0015] Furthermore, a one-way valve is arranged on the fluid passage; or two upper and lower one-way valves are arranged on the fluid passage.

[0016] Furthermore, two piezoelectric pumps are axially stacked to form a cavity between the two piezoelectric pumps as an outlet flow channel, and the positive pressure fluid outlets of the two piezoelectric pumps are both arranged toward the cavity and connected to each other, and an exhaust channel is led out from the side of the cavity.

[0017] Furthermore, three piezoelectric pumps are axially stacked to form a cavity between the middle piezoelectric pump and one of the adjacent piezoelectric pumps. The positive-pressure fluid outlets of the piezoelectric pumps on the upper and lower sides are both oriented toward the middle piezoelectric pump and are interconnected. A hole connected to the cavity is penetrated through the middle piezoelectric pump, and a separate exhaust duct is led out from the side of the cavity.

[0018] Compared with the existing technology, the above technical solution has the following beneficial effects:

[0019] 1. A through hole is opened in the center of the piezoelectric ceramic of the fluid actuator to avoid the dead point in the middle of the piezoelectric ceramic where it cannot be stretched or expanded, and also disconnect the connection and traction between the stretching and the expansion, thereby increasing the vibration amplitude of the fluid actuator and achieving better fluid transportation effect;

[0020] 2. The connecting channel connecting the upper and lower pump chambers is directly set on the fluid actuator, which reduces the external connecting pipes and makes the whole more simple and beautiful;

[0021] 3. A filter mesh is directly installed on the negative pressure fluid suction port of the piezoelectric pump to avoid the problem of failure of the piezoelectric pump caused by blockage of the one-way valve after the fluid flows through the one-way valve. On the one hand, it can ensure the reliability of the piezoelectric pump, so that the fluid can be output normally and continuously to ensure work efficiency. On the other hand, it can extend the service life of the piezoelectric pump and reduce the cost of use to a certain extent.

[0022] 4. Through the flexible setting of the axial superposition pump, it can be changed according to the demand for fluid transportation pressure. The combination is simple and can be applied to more application scenarios. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0024] Figure 1 is a schematic structural diagram of the fluid actuator in the present invention;

[0025] Figure 2 It corresponds to Figure 1 A magnified view of part A in FIG.

[0026] Figure 3 is a pressure diagram of the fluid actuator of the present invention when it vibrates periodically;

[0027] Figure 4 is a schematic diagram of a partial structure of a fluid actuator in Example 1 of the present invention;

[0028] Figure 5 It is a schematic structural diagram of the fluid actuator in the present invention when the deformable steel sheet 3 is bonded and fixed to a side of the piezoelectric ceramic 1 away from the flexible electrical connection sheet 2;

[0029] Figure 6 It is a schematic structural diagram of the fluid actuator in the present invention when the communication channel 4 is opened through the peripheral flexible area 21 of the flexible electrical connection sheet 2;

[0030] Figure 7 It is a schematic diagram of the structure of the piezoelectric pump in the present invention;

[0031] Figure 8 It is a schematic diagram of the explosion structure of the piezoelectric pump in the present invention;

[0032] Fig. 9 It is one of the schematic diagrams of the flow route of the fluid in the piezoelectric pump of the present invention;

[0033] Fig.10 This is the second schematic diagram of the flow path of the fluid in the piezoelectric pump of the present invention;

[0034] Fig.11 It is a schematic structural diagram of an axial superposition pump formed by superimposing two piezoelectric pumps in the present invention;

[0035] Fig.12 It is a schematic diagram of the explosion structure when two piezoelectric pumps are superimposed to form an axial superposition pump in the present invention;

[0036] Fig.13 It is a simplified structural diagram of the case where two upper and lower one-way valves 54 are provided on the fluid passage 57 in Embodiment 7 of the present invention;

[0037] Fig.14 is a schematic structural diagram of a one-way valve 54 provided on a fluid passage 57 in Embodiment 8 of the present invention;

[0038] Fig.15 It is a schematic structural diagram of an axial superposition pump formed by superimposing three piezoelectric pumps in the present invention;

[0039] Fig.16 It is a schematic diagram of the explosion structure when three piezoelectric pumps are superimposed to form an axial superposition pump in the present invention;

[0040] Fig.17 It is a schematic structural diagram of the embodiment 9 of the present invention when two upper and lower one-way valves 54 are respectively provided on two fluid passages 57;

[0041] Fig.18 This is a simplified structural diagram of a case where two upper and lower one-way valves 54 are provided on one fluid passage 57 and one one-way valve 54 is provided on the other fluid passage 57 in Embodiment 9 of the present invention;

[0042] Fig.19 is a simplified structural diagram of Embodiment 10 of the present invention;

[0043] Fig. 20 It is a simplified structural diagram of embodiment 11 of the present invention.

[0044] Description of reference numerals:

[0045] 1. Piezoelectric ceramics; 11. Through hole;

[0046] 2. Flexible electrical connection sheet; 21. Peripheral flexible area; 22. Extension; 221. Actuator electrical interface;

[0047] 3. Deformed steel sheet;

[0048] 4. Connecting channel;

[0049] 5. Pump housing; 51. Pump chamber; 52. Positive pressure fluid outlet; 53. Negative pressure fluid inlet; 54. One-way valve; 55. Filter mesh; 56. Air pipe joint; 57. Fluid passage; 58. Hole. DETAILED DESCRIPTION

[0050] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0051] In view of the problems existing in the prior art, the present invention provides a fluid actuator, a piezoelectric pump and a bearing superposition pump. The present invention is described in detail below with reference to the accompanying drawings.

[0052] Example 1

[0053] See also Figure 1-4 As shown, a fluid actuator, driven by a periodic voltage signal of more than 20KHz, makes periodic vibrations and forms ultrasonic standing waves, which is mainly used in ultrasonic piezoelectric pumps. The fluid actuator includes:

[0054] Piezoelectric ceramic 1, two electrodes are arranged on the piezoelectric ceramic 1, one of which is a positive electrode and the other is a negative electrode, and the two electrodes are arranged on the upper and lower surfaces of the piezoelectric ceramic 1 respectively, and one of the electrodes is bent along the side of the piezoelectric ceramic 1 and extends to the other surface, that is, the longitudinal section of the electrode located on the side of the piezoelectric ceramic 1 is a C-shaped structure, and finally the wiring terminals of the two electrodes are located on the same surface. A through hole 11 is opened through the center of the piezoelectric ceramic 1. Compared with the piezoelectric ceramic without a hole, the through hole 11 can avoid the dead point in the middle position where it cannot be stretched or expanded, and also disconnects the connection traction between the expansion and contraction, thereby increasing the action amplitude of the fluid actuator and making the effect better. Specifically, the aperture of the through hole 11 is between 0.5-10mm, and preferably, the aperture of the through hole 11 is opened to 3mm.

[0055] A flexible electrical connection sheet 2 is pasted on one side of the piezoelectric ceramic 1 with the two electrode terminals and electrically connected to the two electrode terminals to form a loop. The outer diameter of the main body of the flexible electrical connection sheet 2 connected to the piezoelectric ceramic 1 should be larger than the outer diameter of the piezoelectric ceramic 1, so that after the main body of the flexible electrical connection sheet 2 is connected to the piezoelectric ceramic 1, there is still a certain peripheral flexible area 21 on the periphery of the piezoelectric ceramic 1. The main body of the flexible electrical connection sheet 2 has an extension portion 22, and an actuator electrical interface 221 is provided at the end of the extension portion 22.

[0056] The deformed steel sheet 3 is bonded to the surface of the flexible electrical connection sheet 2 away from the piezoelectric ceramic 1 .

[0057] The communicating channel 4 is used to communicate the upper and lower spaces of the actuator. The communicating channel 4 is provided with at least one communicating channel 4, and the aperture of the communicating channel 4 should be not less than 0.3 mm. The communicating channel 4 can be provided at any position of the actuator except the center. Specifically, the communicating channel 4 can sequentially penetrate the piezoelectric ceramic 1, the flexible electrical connection sheet 2 and the deformable steel sheet 3.

[0058] When the fluid actuator is actually working, the piezoelectric ceramic 1 can shrink or expand radially under the action of the external alternating voltage. As the frequency increases, it will drive the deformed steel sheet 3 to undergo elastic deformation. The deformation of the deformed steel sheet 3 is very difficult in the radial direction, so it will be transformed into axial deformation. The direction of deformation changes with the shrinkage or expansion deformation, bringing about vibration peaks and troughs. As the frequency of the alternating voltage increases, continuous peaks and troughs will be brought about on the upper and lower sides of the fluid actuator, thereby promoting the movement of the fluid in cooperation with the one-way valve of the pump body.

[0059] It should be specifically explained that the flexible electrical connection sheet 2 of the present application is formed by pressing a resin material and an ultra-thin conductive copper sheet. Preferably, the resin material is a PI film material.

[0060] Example 2

[0061] See also Figure 5 As shown, the difference between this embodiment and embodiment 1 is that the deformed steel sheet 3 is bonded and fixed to a side of the piezoelectric ceramic 1 away from the flexible electrical connection sheet 2 .

[0062] A hole may also be provided through the center of the deformed steel sheet 3 described in the present application.

[0063] Example 3

[0064] See also Figure 6 As shown, the difference between this embodiment and the first embodiment is that the communication channel 4 is opened through the outer flexible area 21 of the flexible electrical connection sheet 2 .

[0065] Example 4

[0066] On the basis of any one of embodiments 1-3, a glue hole (not specifically marked in the figure) is opened through the bonding area between the flexible electric connecting sheet 2 and the piezoelectric ceramic 1 or the deformed steel sheet 3, so that the glue can easily overflow on both sides, and the flexible electric connecting sheet 2 and the deformed steel sheet 3 or the piezoelectric ceramic 1 can be better bonded into a whole. When the piezoelectric ceramic 1 is driven by an alternating voltage, it can operate more reliably and improve performance.

[0067] Example 5

[0068] See also Figure 7-10 As shown, a piezoelectric pump includes a pump housing 5 and a fluid actuator as described in any one of embodiments 1-4, wherein the fluid actuator is installed inside the pump housing 5 to separate the internal space of the pump housing 5 into two upper and lower pump chambers 51, and the upper and lower pump chambers 51 can be connected through a connecting channel 4 opened on the fluid actuator.

[0069] The upper and lower parts of the pump housing 5 are respectively provided with a positive pressure fluid outlet 52 and a negative pressure fluid inlet 53, and the positive pressure fluid outlet 52 and the negative pressure fluid inlet 53 are preferably provided at the center of the pump housing 5. A one-way valve 54 is respectively installed on the positive pressure fluid outlet 52 and the negative pressure fluid inlet 53.

[0070] The ultrasonic standing wave generated by the periodic vibration of the fluid actuator changes the space of the upper and lower pump chambers 51, thereby generating pressure to open or close the two one-way valves 54. Specifically, the two one-way valves 54 are both facing the antinode of the ultrasonic standing wave, and the one-way valves 54 are both closed when the fluid actuator moves toward the negative pressure fluid suction port 53, and the fluid in the pump chamber 51 on the negative pressure fluid suction port 53 side is discharged into the other pump chamber 51 through the connecting channel 4; when the one-way valves 54 move toward the positive pressure fluid outlet 52 side, they are both opened, and the external fluid enters the pump chamber 51 on the negative pressure fluid suction port 53 side through the negative pressure fluid suction port 53, while the fluid in the pump chamber 51 close to the positive pressure fluid outlet 52 flows out.

[0071] In the piezoelectric pump described above, under the action of the peaks and troughs generated by the fluid actuator, the fluid can flow into one passage and flow out of another passage, and the connecting channel 4 is arranged inside the pump housing 5. The advantage of this is that the pipeline can be greatly reduced and the output fluid pressure can be made higher. Every time the fluid passes through a one-way valve 54, the pressure value can be increased by about 20Kpa.

[0072] Example 6

[0073] See also Figure 7-Figure 8 As shown, this embodiment is based on the embodiment 5, and an air pipe connector 56 is provided on the positive pressure fluid outlet 52, so that the pipeline can be plugged in.

[0074] A fixed filter mesh 55 is installed outside the negative pressure fluid inlet 53. The filter mesh 55 is made of a fine mesh material with a mesh size of 300 or more, and is used to filter particles in the fluid to prevent the tiny pores flowing through the one-way valve 54 from being blocked and causing failure. In this way, the piezoelectric pump can be equipped with a filter mesh 55 for filtering the fluid, which can better ensure the reliability of the piezoelectric pump, increase the service life of the piezoelectric pump, and reduce the cost to a certain extent.

[0075] Example 7

[0076] See also Figure 11-13 As shown, an axially stacked pump is formed by stacking at least two piezoelectric pumps as described in any one of embodiments 5-6 in the axial direction. When two adjacent piezoelectric pumps are connected, the positive pressure fluid outlet 52 of one piezoelectric pump is connected to the negative pressure fluid inlet 53 of another piezoelectric pump to form a fluid passage 57, which can make the fluid flow through each cavity in an orderly manner under the drive of the fluid driver. Such a pump can bring greater pressure and is more compact in structure. In this embodiment, the air pipe joint 56 needs to be set at the positive pressure fluid outlet 52 of the piezoelectric pump at the end.

[0077] The axially stacked pump form can eventually form at least four pump chambers 51. If two piezoelectric pumps are stacked axially, four pump chambers 51 will be formed, and eventually a fluid passage 57 will be formed.

[0078] like Fig.13 As shown, two one-way valves 54 are arranged on the fluid passage 57, and the two one-way valves 54 are consistent with the one-way valves 54 arranged at the head and tail ends of the superimposed pump in the flow direction. Experiments have shown that the fluid pressure can be increased by 20Kpa each time the fluid passes through a one-way valve 54, and the fluid pressure can be increased to 80Kpa when the fluid flows through four one-way valves 54 in an orderly manner.

[0079] Example 8

[0080] like Fig.14 As shown, the difference between this embodiment and Embodiment 7 is that only one one-way valve 54 is provided on the fluid passage 57, so that the number of the one-way valves 54 of the entire superimposed pump is three. For the usage scenario that only requires a smaller pressure, such as 60Kpa, such a superimposed pump form is also feasible.

[0081] Example 9

[0082] like Figure 15-18As shown, the difference between this embodiment and embodiment 7 is that three piezoelectric pumps as described in any one of embodiments 5-6 are stacked in the axial direction, and six pump chambers 51 are formed at this time, and two fluid passages 57 are formed, and two one-way valves 54 are respectively provided on the two fluid passages 57, or one one-way valve 54 is respectively provided, or two one-way valves 54 are provided on one fluid passage 57, and one one-way valve 54 is provided on the other fluid passage 57. The number of one-way valves 54 on the fluid passage 57 can be flexibly varied according to actual needs.

[0083] Of course, the axial superposition pump described in this application is not limited to the axial superposition form of two or three piezoelectric pumps described above, and can even be four or five. Such a superposition method can quickly superimpose more required pump bodies, with various changes and relatively simple combinations.

[0084] Example 10

[0085] like Fig.19 As shown, the axial superposition pump of this embodiment is formed by superimposing two piezoelectric pumps in the axial direction. Specifically, a cavity is formed between the two piezoelectric pumps as an outlet flow channel, and the positive pressure fluid outlets 52 of the two piezoelectric pumps are both arranged toward the cavity and connected to each other. The pump cavity 51 of the piezoelectric pump is connected to the cavity through the positive pressure fluid outlet 52, and an exhaust channel is led out on the side of the cavity. At the same time, the negative pressure fluid outlets 53 of the two piezoelectric pumps are both arranged away from the cavity, and a filter mesh 55 is installed on the negative pressure fluid inlet 53.

[0086] Embodiment 11

[0087] like Fig. 20 As shown, the axial stacking pump of this embodiment uses three piezoelectric pumps stacked axially, and a cavity is formed between the piezoelectric pump in the middle and one of the adjacent piezoelectric pumps. The positive pressure fluid outlets 52 of the piezoelectric pumps on the upper and lower sides are both oriented toward the piezoelectric pump in the middle and are connected to each other. A hole 58 connected to the cavity is provided through the piezoelectric pump in the middle, and a separate exhaust duct is led out from the side of the cavity. In the axial stacking pump formed by such connection, the fluid enters through the piezoelectric pumps on the upper and lower sides and is finally discharged into the pump cavity 51 of the piezoelectric pump in the middle, and then is discharged into the cavity through the hole 58 and discharged from the exhaust duct on the side of the cavity.

[0088] Specifically, filter meshes 55 are installed on the negative pressure fluid outlets 53 of the piezoelectric pumps at the upper and lower sides.

[0089] In the description of the present invention, unless otherwise specified, “plurality” means two or more than two; the orientations or positional relationships indicated by terms such as “upper”, “lower”, “left”, “right”, “inside”, “outside”, “front end”, “rear end”, “head” and “tail” are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0090] The above description is only used to illustrate the technical solution of the present invention rather than to limit it. Other modifications or equivalent substitutions made to the technical solution of the present invention by ordinary technicians in this field should be included in the scope of the claims of the present invention as long as they do not depart from the spirit and scope of the technical solution of the present invention.

Claims

1. A fluid actuator, characterized in that: include: A piezoelectric ceramic, wherein a through hole is formed in the center of the piezoelectric ceramic, and two electrodes are arranged on the piezoelectric ceramic, the two electrodes have opposite polarities and are arranged on the upper and lower surfaces of the piezoelectric ceramic respectively, and one of the electrodes is bent along the side of the piezoelectric ceramic and extends to the other surface, so that the connection terminals of the two electrodes are located on the same side; A flexible electrical connection sheet, which is attached to the piezoelectric ceramic and electrically connected to the connection terminals of the two electrodes to form a loop. After the flexible electrical connection sheet is connected to the piezoelectric ceramic, it is located on the outer periphery of the piezoelectric ceramic to form an outer flexible area; A deformed steel sheet, wherein the deformed steel sheet is bonded to the surface of the flexible electrical connection sheet away from the piezoelectric ceramic; or the deformed steel sheet is bonded to the surface of the piezoelectric ceramic away from the flexible electrical connection sheet; The communication channel is opened through any position of the actuator except the center, so that the two spaces above and below the actuator are connected.

2. The fluid actuator according to claim 1, characterized in that: The communication channel sequentially passes through the piezoelectric ceramic, the flexible electric connection sheet and the deformed steel sheet.

3. The fluid actuator according to claim 1, characterized in that: The communication channel is opened through the peripheral flexible area.

4. The fluid actuator according to claim 1, characterized in that: The flexible electrical connection sheet is formed by pressing a resin material and an ultra-thin conductive copper sheet.

5. The fluid actuator according to claim 1, characterized in that: The adhesive hole is formed through the adhesive area between the flexible electrical connection sheet and the piezoelectric ceramic or the deformed steel sheet.

6. A piezoelectric pump, characterized in that: It includes a pump housing and a fluid brake as described in any one of claims 1 to 5, wherein the fluid actuator is installed inside the pump housing to divide the internal space of the pump housing into two upper and lower pump chambers, and the upper and lower parts of the pump housing are respectively penetrated by a positive-pressure fluid outlet and a negative-pressure fluid inlet, and a one-way valve is respectively installed on the positive-pressure fluid outlet and the negative-pressure fluid inlet.

7. The piezoelectric pump according to claim 6, characterized in that The two one-way valves are both closed when the fluid actuator moves toward the negative-pressure fluid suction port side; the two one-way valves are both opened when the fluid actuator moves toward the positive-pressure fluid outlet side.

8. The piezoelectric pump according to claim 6, characterized in that A filter mesh is fixedly installed on the outside of the negative pressure fluid suction port.

9. An axial superposition pump, characterized in that: It is formed by axially stacking at least two piezoelectric pumps as described in any one of claims 6 to 8. When two adjacent piezoelectric pumps are connected, the positive pressure fluid outlet of one piezoelectric pump is connected to the negative pressure fluid intake port of another piezoelectric pump to form a fluid passage.

10. The axial superposition pump according to claim 9, characterized in that: A one-way valve is arranged on the fluid passage; or two upper and lower one-way valves are arranged on the fluid passage.

11. The axial superposition pump according to claim 9, characterized in that: Two piezoelectric pumps are stacked axially to form a cavity between the two piezoelectric pumps as an outlet flow channel, and the positive pressure fluid outlets of the two piezoelectric pumps are both arranged toward the cavity and connected to each other, and an exhaust channel is led out from the side of the cavity.

12. The axial superposition pump according to claim 9, characterized in that: Three piezoelectric pumps are stacked axially, and a cavity is formed between the middle piezoelectric pump and one of the adjacent piezoelectric pumps. The positive pressure fluid outlets of the piezoelectric pumps on the upper and lower sides are both oriented toward the middle piezoelectric pump and are interconnected. A hole connected to the cavity is penetrated through the middle piezoelectric pump, and a separate exhaust duct is led out from the side of the cavity.

Images