Piezoelectric wafer pump

Abstract

The invention relates to a piezoelectric wafer pump, and belongs to the technical field of piezoelectric pumps, the piezoelectric wafer pump comprises a piezoelectric actuator and a plurality of groups of double-cavity diaphragm pumps driven by the piezoelectric actuator, the piezoelectric actuator comprises a comb finger type resonator, a bolt connector and a screw connector, the comb finger type resonator comprises a cross beam and a plurality of driving arms distributed on the top surface of the cross beam at equal intervals, the bolt connector is arranged on the driving arm located on the outermost side, and the screw connector is arranged on the driving arm located on the inner side. The double-cavity diaphragm pump is positioned between two adjacent driving arms and is suspended above the top surface of the cross beam; piezoelectric patches are horizontally arranged on the top face and the bottom face of the cross beam and the bottom ends of the two side faces of the driving arm in pairs, and all the piezoelectric patches are connected in series or in parallel. The comb finger type driver is adopted to drive the multiple sets of double-cavity diaphragm pumps, only one driving power source is needed, the complexity and the control requirement of the driving power source needed by the multi-pump-body resonant piezoelectric pump can be effectively lowered, and the output performance and the working reliability are improved.

Description

Technical Field

[0001] This invention belongs to the field of piezoelectric pump technology, specifically relating to a piezoelectric wafer pump that uses a comb-finger resonator to drive a multi-diaphragm pump. Background Technology

[0002] A piezoelectric pump is a novel fluid transport device that utilizes the inverse piezoelectric effect of piezoelectric materials to induce mechanical deformation in a piezoelectric oscillator, driving periodic changes in the volume of the pump chamber. This, combined with a check valve, enables fluid pumping. Compared to traditional pumps, piezoelectric pumps offer advantages such as compact structure, low power consumption, high efficiency, high power density, high precision, and fast response. They have broad application prospects in fields such as biomedicine, fuel supply, liquid cooling, and precision actuation.

[0003] Compared to other driving mechanisms, the biggest drawback of piezoelectric actuators is their small output displacement, which also leads to the generally low output performance of current piezoelectric pumps. To improve the output characteristics of piezoelectric pumps, one approach is to operate the piezoelectric actuator in a resonant state to increase its output displacement and driving force, thereby obtaining a resonant piezoelectric pump with high flow and pressure output. Another approach is to design a piezoelectric pump with a multi-pump structure, using series, parallel, or hybrid connections of multiple diaphragm pumps to improve the overall output performance of the piezoelectric pump.

[0004] Designing resonant piezoelectric pumps and multi-piezoelectric pump systems are two effective methods to improve piezoelectric pump performance. However, there is currently no research combining these two methods, i.e., constructing a multi-piezoelectric resonant piezoelectric pump system. This is because, for multi-piezoelectric resonant piezoelectric pumps, even using piezoelectric actuators of the same structure and size, the resonant frequencies of different piezoelectric pumps will differ due to manufacturing and assembly errors, as well as differences in the working environment and operating conditions of each pump. This means that multiple pumps cannot share the same drive power supply. To ensure that each piezoelectric pump in a multi-piezoelectric resonant piezoelectric pump operates at its optimal state, multiple drive power supplies need to be set up, and the output frequency of each drive power supply needs to be adjusted to the resonant frequency of the corresponding piezoelectric pump. This will greatly increase the complexity and cost of the system and reduce its reliability. Summary of the Invention

[0005] To address the problems of complex drive circuits, high control costs, and low reliability caused by inconsistent resonant frequencies among piezoelectric pumps in multi-pump resonant piezoelectric pump systems, this invention designs a piezoelectric wafer pump that uses a comb-finger resonator to drive multiple diaphragm pumps.

[0006] A piezoelectric wafer pump includes a piezoelectric actuator and multiple sets of dual-chamber diaphragm pumps driven therefrom. The piezoelectric actuator includes a comb-finger resonator, a bolt connector, and a screw connector. The comb-finger resonator includes a crossbeam and a plurality of drive arms that are vertically fixed on the top surface of the crossbeam and are equidistantly distributed. The bolt connector is disposed on the outermost drive arm, and the screw connector is disposed on the inner drive arm. The dual-chamber diaphragm pump is located between two adjacent drive arms and suspended above the top surface of the crossbeam. One power input end of the dual-chamber diaphragm pump is fixedly connected to the screw connector, and the other end is fixedly connected to the bolt connector or screw connector. The two adjacent sets of dual-chamber diaphragm pumps have opposite working phases and the same resonant frequency. Pairs of piezoelectric plates are horizontally arranged on the top and bottom surfaces of the crossbeam, corresponding to each dual-chamber diaphragm pump directly below it. Pairs of piezoelectric plates are vertically arranged at the bottom ends of both sides of the drive arm. All piezoelectric plates are connected in series or in parallel. When the excitation frequency of the AC power applied to the piezoelectric plate is the inverse bending resonant frequency of the piezoelectric actuator, the comb-finger resonator simultaneously drives multiple sets of dual-cavity diaphragm pumps to continuously pump fluid at the same resonant frequency.

[0007] Furthermore, the drive arm has a vertically arranged waist-shaped hole, and a connecting bolt or connecting screw is provided in the waist-shaped hole. The end of the bolt connector away from the dual-chamber diaphragm pump is threadedly connected to the connecting bolt, and the end of the screw connector away from the dual-chamber diaphragm pump is fixedly connected to the end of the connecting screw by a first bolt.

[0008] Furthermore, the connecting screw has an external thread section in the middle, and two nuts are threaded onto the external thread section. The two nuts are located on both sides of the waist-shaped hole of the drive arm. Bosses are provided at both ends of the connecting screw, and lateral through holes are provided at the bosses. The first bolt passes through the lateral through holes and is threaded to the end of the screw connector.

[0009] Furthermore, a mass block located on the top side of the dual-chamber diaphragm pump is fixedly disposed at the top of the drive arm, and an additional mass block is fixedly connected to the top of the mass block.

[0010] Furthermore, the crossbeam, drive arm, and mass block are integrally formed structures.

[0011] Furthermore, the drive arm has a width of 5~100mm, a thickness of 0.5~5mm, and a length of 10~100mm, and the crossbeam has the same width as the drive arm, a thickness of 0.5~5mm, and a length equal to the distance between the outer sides of the two outermost drive arms.

[0012] Furthermore, the piezoelectric sheet is made of piezoelectric ceramic or piezoelectric single crystal, and has a thickness of 0.01 to 1 mm, a width the same as the width of the drive arm / beam, and a length of 1 to 50 mm.

[0013] Furthermore, the comb-finger resonator is made of metal, and its surface, except for the area in contact with the piezoelectric sheet, is coated with an insulating layer.

[0014] Furthermore, the dual-chamber diaphragm pump is stacked, consisting of two diaphragm pumps fixed back to back.

[0015] Furthermore, the fluid channels of the two diaphragm pumps in each set of dual-chamber diaphragm pumps are connected in parallel or in series, and the fluid channels of each set of dual-chamber diaphragm pumps are connected in parallel or in series.

[0016] Compared with the prior art, the beneficial technical effects of the present invention are reflected in the following aspects: (1) The present invention proposes a novel piezoelectric actuator structure, which can drive multiple diaphragm pumps simultaneously in the resonant state using one actuator. Only one drive power supply is needed, which effectively reduces the complexity of the drive power supply and control requirements of the multi-pump resonant piezoelectric pump, and improves the output performance and working reliability.

[0017] (2) The piezoelectric actuator of the present invention adopts a comb-finger structure design, with a drive beam and multiple drive arms. Adjacent drive arms form a drive unit similar to a tuning fork. The length of the drive beam and the number of drive arms can be adjusted according to the number of pumps to be driven. The design is flexible and easy to process. The working mode of the piezoelectric actuator is the anti-phase bending resonance mode. This resonance mode has the characteristics of uniform strain distribution on the piezoelectric sheet surface and high mechanical quality factor, thus resulting in high driving performance and good working reliability.

[0018] (3) In the piezoelectric drive mechanism of the present invention, the amplitude of the drive arm and the resonant frequency of the piezoelectric drive mechanism can be adjusted by changing parameters such as the thickness of the drive arm and the size of the additional mass block, so as to match the optimal working frequency of the diaphragm pump and make the working performance of the piezoelectric pump reach the best.

[0019] (4) The present invention uses a recyclable piezoelectric actuator and a replaceable diaphragm pump, which makes it easy to replace damaged parts and reduce the cost of use; the fluid channels of multiple diaphragm pumps can be connected in parallel or in series, making it easy to adjust the overall output performance of the piezoelectric pump; the installation position of the diaphragm pump on the piezoelectric actuator is easy to adjust, and the mechanical impedance matching characteristics between the piezoelectric actuator and the diaphragm pump can be easily adjusted to achieve the best impedance matching. Attached Figure Description

[0020] Figure 1 This is a three-dimensional structural schematic diagram of the piezoelectric wafer pump in Embodiment 1 of the present invention; Figure 2 This is a schematic diagram of the piezoelectric actuator in Example 1; Figure 3 This is a schematic diagram of the polarization direction setting of each piezoelectric element and the connection method of the driving power supply when the piezoelectric elements are set as parallel piezoelectric bicrystalline wafers in Example 1; Figure 4 This is a schematic diagram of the polarization direction setting of each piezoelectric element and the connection method of the driving power supply when the piezoelectric elements are set as a series piezoelectric bicrystalline wafer in Example 1; Figure 5 This is a cross-sectional view of the piezoelectric wafer pump in Embodiment 1 of the present invention; Figure 6 This is a schematic diagram of the deformation mode of the piezoelectric actuator and the working state of the diaphragm pump when the excitation voltage of the driving power supply is positive in Example 1. Figure 7 This is a schematic diagram of the deformation mode of the piezoelectric actuator and the working state of the diaphragm pump when the excitation voltage of the driving power supply is negative in Example 1. Figure 8 This is a simulation diagram of the deformation of the piezoelectric actuator driving two sets of dual-cavity diaphragm pumps in the anti-phase bending resonant mode in Embodiment 1 of the present invention; Figure 9 This is a schematic diagram showing that the fluid channels of different groups of dual-chamber diaphragm pumps in Example 1 are connected in parallel; Figure 10 This is a schematic diagram showing that the fluid channels of different groups of dual-chamber diaphragm pumps in Example 1 are connected in series; Figure 11 This is a three-dimensional structural schematic diagram of the piezoelectric wafer pump in Embodiment 2 of the present invention; Figure 12 This is a simulation diagram of the deformation of the piezoelectric actuator in Example 2 driving three sets of dual-chamber diaphragm pumps in the reverse bending resonant mode.

[0021] In the diagram: 1. Comb-finger resonator; 101. Crossbeam; 102. First end drive arm; 103. Second end drive arm; 104. Middle drive arm; 105. Additional mass block; 106. Mass block; 107. Through hole; 2. Bolt connector; 3. Screw connector; 4. First dual-chamber diaphragm pump; 401. First left pump chamber diaphragm; 402. First right pump chamber diaphragm; 403. Pump chamber; 404. Inlet check valve; 405. Outlet check valve; 406. Inlet flow channel; 407. Outlet flow channel; 5. Second dual-chamber diaphragm pump; 501. Second left pump chamber diaphragm; 502. Second right pump chamber 6. Diaphragm; 7. Connecting screw; 8. Connecting bolt; 9. First bolt; 10. Second bolt; 11. Nut; 12. First piezoelectric bicrystalline wafer; 13. First piezoelectric element; 14. Second piezoelectric element; 15. Second piezoelectric bicrystalline wafer; 16. Third double-chamber diaphragm pump; 17. Third double-chamber diaphragm pump. Detailed Implementation

[0022] The preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, so that the advantages and features of the present invention can be more easily understood by those skilled in the art, thereby providing a clearer and more explicit definition of the scope of protection of the present invention.

[0023] It should be noted that when a component is said to be "installed on" another component, it can be directly on the other component or it may be in a component that is centered on it. When a component is said to be "set on" another component, it can be directly set on the other component or it may also be in a component that is centered on it. When a component is said to be "fixed to" another component, it can be directly fixed to the other component or it may also be in a component that is centered on it.

[0024] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the specification of this invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "or / and" as used herein includes any and all combinations of one or more of the associated listed items. Example

[0025] See Figure 1 and Figure 2A piezoelectric wafer pump includes a piezoelectric actuator and a first dual-chamber diaphragm pump 4 and a second dual-chamber diaphragm pump 5 driven by the actuator. The piezoelectric actuator includes a comb-finger resonator 1, a bolt connector 2, and a screw connector 3. The comb-finger resonator 1 includes a crossbeam 101 and a first end drive arm 102 and a second end drive arm 103, respectively vertically fixed at both ends of the top surface of the crossbeam 101, and an intermediate drive arm 104 vertically fixed at the middle of the top surface of the crossbeam 101. That is, the first end drive arm 102, the intermediate drive arm 104, and the second end drive arm 103 are equidistantly distributed on the top surface of the crossbeam 101. Mass blocks 106 are fixedly disposed on the top right side of the top of the first end drive arm 102, the top left side of the top of the second end drive arm 103, and both sides of the top of the intermediate drive arm 104, respectively, located on the top sides of the first dual-chamber diaphragm pump 4 / second dual-chamber diaphragm pump 5. An additional mass block 105 is disposed on the top of the mass blocks 106. The mass block 106 has a threaded hole, and the additional mass block 105 has a bolt through hole corresponding to the threaded hole. A second bolt 9 is installed in the bolt through hole, and the end of the second bolt 9 is threadedly connected to the threaded hole, so that the additional mass block 105 is fixedly connected to the mass block 106.

[0026] In this embodiment, all drive arms have the same dimensions, ranging from 5 to 100 mm in width, 0.5 to 5 mm in thickness, and 10 to 100 mm in length. The crossbeam 101 has the same width as each drive arm, a thickness of 0.5 to 5 mm, and a length equal to the distance between the outer sides of the first end drive arm 102 and the second end drive arm 103. Preferably, the crossbeam 101, each drive arm, and each mass block 106 are integrally formed, i.e., the comb-finger resonator 1 is an integral structure with the same wall thickness in all parts. Its material is metal, and its surface, except for the area in contact with each piezoelectric sheet, is coated with an insulating layer. By changing parameters such as the thickness of the drive arm and the size of the additional mass block, the amplitude of the drive arm and the resonant frequency of the piezoelectric drive mechanism can be adjusted to match the optimal operating frequency of the diaphragm pump, thereby optimizing the performance of the piezoelectric pump.

[0027] See Figure 2In this embodiment, there are two bolt connectors 2, respectively disposed on the inner sides of the first end drive arm 102 and the second end drive arm 103. There are also two screw connectors 3, disposed on both sides of the intermediate drive arm 104. Specifically, the first end drive arm 102, the second end drive arm 103, and the intermediate drive arm 104 all have through holes 107 located on the same horizontal axis in their middle portions. Connecting bolts 7 are respectively disposed in the through holes 107 on the first and second end drive arms 102 and 103, and connecting screws 6 are disposed in the through holes 107 on the intermediate drive arm 104. The inner end of the bolt connector 2 is a connecting flange structure, and the outer end is a cylindrical structure. A threaded hole is provided on the outer end face of the cylindrical structure. The threaded end of the connecting bolt 7 passes through the through hole 107 and is threadedly connected to the threaded hole on the outer end face of the bolt connector 2, thereby fixing the two bolt connectors 2 relatively on the first end drive arm 102 and the second end drive arm 103.

[0028] The connecting screw 6 has an external threaded section in the middle, on which two nuts 10 are threadedly connected. The two nuts 10 are located on both sides of the through hole 107 of the intermediate drive arm 104. Thus, the connecting screw 6 is fixedly connected to the intermediate drive arm 104 through the threaded engagement of the two nuts 10 with the external threaded section. The length of the connecting screw 6 on both sides of the intermediate drive arm 104 is equal to ensure symmetrical connection on both sides. Both ends of the connecting screw 6 are provided with bosses, and the bosses have lateral through holes. A first bolt 8 is installed in the lateral through holes. The screw connector 3 has a connecting flange structure at one end near the bolt connector 2 and a rectangular column structure at the other end. Threaded holes are opened on the side of the rectangular column. The first bolt 8 passes through the lateral through hole and is threadedly connected to the threaded hole at the end of the screw connector 3. Thus, the two screw connectors 3 are symmetrically fixedly connected to both sides of the intermediate drive arm 104. The two screw connectors 3 are respectively positioned opposite the two bolt connectors 2 and are used to clamp and connect the first dual-chamber diaphragm pump 4 and the second dual-chamber diaphragm pump 5.

[0029] like Figure 5As shown, in this embodiment, the dual-chamber diaphragm pump is stacked and consists of two diaphragm pumps fixed back to back. The first dual-chamber diaphragm pump 4 is located between the first end drive arm 102 and the middle drive arm 104 and is suspended above the top surface of the crossbeam 101. Its left power input end (first left pump chamber diaphragm 401) is fixedly connected to the connecting flange structure of the bolt connector 2 fixedly connected to the first end drive arm 102, and its right power input end (first right pump chamber diaphragm 402) is fixedly connected to the connecting flange structure of the screw connector 3 located on the left side fixedly connected to the middle drive arm 104. The second dual-chamber diaphragm pump 5 is located between the second end drive arm 103 and the middle drive arm 104 and is suspended above the top surface of the crossbeam 101. Its right power input end (second right pump chamber diaphragm 502) is fixedly connected to the connecting flange structure of the bolt connector 2 fixedly connected to the second end drive arm 103, and its left power input end (second left pump chamber diaphragm 501) is fixedly connected to the connecting flange structure of the screw connector 3 located on the right side of the middle drive arm 104. In this way, the first dual-chamber diaphragm pump 4 and the adjacent second dual-chamber diaphragm pump 5 are symmetrically arranged in the comb-finger resonator 1, so the two dual-chamber diaphragm pumps have opposite operating phases and the same resonant frequency.

[0030] Preferably, the through hole 107 is a vertically distributed waist-shaped hole. The mounting position of the two dual-chamber diaphragm pumps on the drive arm of the comb-finger resonator 1 can be adjusted along the length of the waist-shaped hole to adjust the mechanical impedance matching characteristics, thereby adjusting the output characteristics of the two sets of dual-chamber diaphragm pumps.

[0031] Pairs of piezoelectric plates are horizontally arranged on the top and bottom surfaces of the crossbeam 101, corresponding to those directly below each dual-chamber diaphragm pump. Pairs of piezoelectric plates are vertically arranged at the bottom ends of both sides of the drive arm. See also Figure 3 and Figure 4In this embodiment, a first piezoelectric sheet 111 and a second piezoelectric sheet 112 are respectively provided on both sides of the root of the first end drive arm 102, forming a first piezoelectric bicrystalline wafer 11; a third piezoelectric sheet 121 and a fourth piezoelectric sheet 122 are respectively provided on the upper and lower surfaces of the crossbeam 101 between the first end drive arm 102 and the middle drive arm 104, forming a second piezoelectric bicrystalline wafer 12; a fifth piezoelectric sheet 131 and a sixth piezoelectric sheet 132 are respectively provided on both sides of the root of the middle drive arm 104, forming a third piezoelectric bicrystalline wafer 13; a seventh piezoelectric sheet 141 and an eighth piezoelectric sheet 142 are respectively provided on the upper and lower surfaces of the crossbeam 101 between the middle drive arm 104 and the second end drive arm 103, forming a fourth piezoelectric bicrystalline wafer 14; and a ninth piezoelectric sheet 151 and a tenth piezoelectric sheet 152 are respectively provided on both sides of the root of the second end drive arm 103, forming a fifth piezoelectric bicrystalline wafer 15. Each piezoelectric element is made of piezoelectric ceramic or piezoelectric single crystal, with a thickness of 0.01–1 mm, a width equal to the width of the drive arm / beam, and a length of 1–50 mm. The comb-finger resonator 1 is made of metal, and its surface, except for the area in contact with each piezoelectric element, is coated with an insulating layer. All piezoelectric elements are connected in series via wires 16 (e.g., ...). Figure 4 (as shown) or all connected in parallel (such as) Figure 3 (as shown), and then connect the AC drive power supply U1.

[0032] The working principle of the piezoelectric wafer pump in this embodiment is described in detail below: See Figure 6 and Figure 7The bending vibration deformation of the first end drive arm 102, the second end drive arm 103, and the middle drive arm 104 can be simultaneously transmitted to the first left pump chamber diaphragm 401, the first right pump chamber diaphragm 402, the second left pump chamber diaphragm 501, and the second right pump chamber diaphragm 502 through the bolt connector 2 and the screw connector 3, causing the four pump chamber diaphragms to undergo elastic vibration deformation simultaneously, thereby causing the sealing volume of the pump chamber 403 to change periodically. Taking two diaphragm pumps in the first dual-chamber diaphragm pump 4 as an example, when the first end drive arm 102 and the middle drive arm 104 pull the bolt connector 2 and the screw connector 3 to deform the first left pump chamber diaphragm 401 and the first right pump chamber diaphragm 402 towards the outside of the corresponding pump chamber 403, the sealing volume of the pump chamber 403 increases and the pressure decreases. Under the action of the internal and external pressure difference, the corresponding inlet check valve 404 opens and the corresponding outlet check valve 405 closes, and the fluid flows into the pump chamber 403 from the corresponding inlet flow channel 406 through the inlet check valve 404. 3. The fluid intake process: When the first end drive arm 102 and the middle drive arm 104 push the bolt connector 2 and the screw connector 3, causing the first left pump chamber diaphragm 401 and the first right pump chamber diaphragm 402 to deform into the corresponding pump chamber 403, the sealing volume of the pump chamber 403 decreases, and the pressure increases. Under the action of the internal and external pressure difference, the corresponding inlet check valve 404 closes, and the corresponding outlet check valve 405 opens. The fluid flows from the pump chamber 403 through the outlet check valve 405 and out of the corresponding outlet flow channel 407, which is the fluid discharge process. The principle of this process is the same for other diaphragm pumps.

[0033] See Figure 6 When the excitation voltage of the AC drive power supply U1 is positive, the direction of the generated electric field intensity is along the thickness direction of each piezoelectric element, and the direction of the electric field intensity is the same as the polarization direction of the first piezoelectric element 111, the fourth piezoelectric element 122, the sixth piezoelectric element 132, the seventh piezoelectric element 141, and the ninth piezoelectric element 151, and opposite to the polarization direction of the second piezoelectric element 112, the third piezoelectric element 121, the fifth piezoelectric element 131, the eighth piezoelectric element 142, and the tenth piezoelectric element 152. Therefore, the middle part of the crossbeam 101 between the first end drive arm 102 and the middle drive arm 104 bends upward, and the middle part of the crossbeam 101 between the second end drive arm 103 and the middle drive arm 104 bends downward. The first end drive arm 102 and the middle drive arm 104 bend away from each other, and the second end drive arm 103 and the middle drive arm 104 bend towards each other. At this time, the first dual-chamber diaphragm pump 4 is in the process of sucking in fluid, and the second dual-chamber diaphragm pump 5 is in the process of discharging fluid.

[0034] See Figure 7When the excitation voltage of the AC drive power supply U1 is negative, the direction of the generated electric field intensity is along the thickness direction of each piezoelectric element, and the direction of the electric field intensity is opposite to the polarization direction of the first piezoelectric element 111, the fourth piezoelectric element 122, the sixth piezoelectric element 132, the seventh piezoelectric element 141, and the ninth piezoelectric element 151, and the same as the polarization direction of the second piezoelectric element 112, the third piezoelectric element 121, the fifth piezoelectric element 131, the eighth piezoelectric element 142, and the tenth piezoelectric element 152. Therefore, the middle part of the crossbeam 101 between the first end drive arm 102 and the middle drive arm 104 bends downward, and the middle part of the crossbeam 101 between the second end drive arm 103 and the middle drive arm 104 bends upward. The first end drive arm 102 and the middle drive arm 104 bend towards each other, and the second end drive arm 103 and the middle drive arm 104 bend away from each other. At this time, the first dual-chamber diaphragm pump 4 is in the process of discharging fluid, and the second dual-chamber diaphragm pump 5 is in the process of sucking fluid.

[0035] See Figure 8 When the excitation frequency of the AC drive power supply U1 is close to the anti-phase bending resonant frequency of the piezoelectric actuator, the comb-finger resonator 1 of the piezoelectric actuator will generate large-amplitude periodic vibrations in the anti-phase bending resonant mode, thereby driving the first dual-chamber diaphragm pump 4 and the second dual-chamber diaphragm pump 5, which are connected to the first end drive arm 102, the second end drive arm 103 and the middle drive arm 104, to continuously pump fluid at the same resonant frequency.

[0036] The driving waveform of the AC drive power supply U1 is an AC sine wave, triangular wave, or square wave, and the driving frequency is the reverse bending resonant frequency of the piezoelectric actuator, or can be adjusted within a certain range around the resonant frequency. The reverse bending resonant frequency of the piezoelectric actuator will vary due to the influence of the driven load (including bolt connector 2, screw connector 3, additional mass block 105, pump chamber diaphragm, pumped fluid, etc.). An oscillation circuit that can automatically track the resonant frequency can be added for closed-loop control.

[0037] The first dual-chamber diaphragm pump 4 and the second dual-chamber diaphragm pump 5 complete one fluid intake process and one fluid discharge process respectively within one vibration cycle of the piezoelectric actuator. When the piezoelectric actuator vibrates in the anti-phase bending resonant mode, the fluid intake process and fluid discharge process of the two diaphragm pumps in the same group are carried out synchronously (phase difference is 0°), while the fluid intake process and fluid discharge process of the first dual-chamber diaphragm pump 4 and the second dual-chamber diaphragm pump 5 in different groups are carried out asynchronously (phase difference is 180°).

[0038] See Figure 9 and Figure 10Since the two dual-chamber diaphragm pumps in the same group synchronously draw in and discharge fluid, they can be connected in parallel using pipelines to increase the flow rate of the fluid pumped by the diaphragm pumps in the same group. The fluid intake and discharge processes between the first dual-chamber diaphragm pump 4 and the second dual-chamber diaphragm pump 5 are asynchronous. When the first dual-chamber diaphragm pump 4 and the second dual-chamber diaphragm pump 5 are connected in parallel, the flow rate of the piezoelectric wafer pump driven by the comb-finger resonator of this invention can be increased, such as... Figure 9 As shown. When the first dual-chamber diaphragm pump 4 and the second dual-chamber diaphragm pump 5 are connected in series, the pressure of the fluid pumped by the piezoelectric wafer pump driven by the comb-finger resonator of this invention can be increased, such as... Figure 10 As shown. Example

[0039] See Figure 11 The difference between this embodiment and Embodiment 1 is that it includes a piezoelectric actuator and three sets of dual-chamber diaphragm pumps. Therefore, a first end drive arm 102 and a second end drive arm 103 are provided on the crossbeam 101 of its comb-finger resonator 1, along with two intermediate drive arms 104 equidistantly distributed between the first end drive arm 102 and the second end drive arm 103. The three sets of dual-chamber diaphragm pumps are a first dual-chamber diaphragm pump 4, a second dual-chamber diaphragm pump 5, and a third dual-chamber diaphragm pump 17. The first dual-chamber diaphragm pump 4 and the second dual-chamber diaphragm pump 5 are assembled in the same way on the comb-finger resonator 1. The difference is that in embodiment 1, the first dual-chamber diaphragm pump 4 and the second dual-chamber diaphragm pump 5 are connected by the same connecting screw 6; while in this embodiment, a connecting screw 6 is provided on each of the two intermediate drive arms 104. The right power input end of the first dual-chamber diaphragm pump 4 is connected to the left end of the left connecting screw 6, and the left power input end of the second dual-chamber diaphragm pump 5 is connected to the right end of the right connecting screw 6. The two power input ends of the third dual-chamber diaphragm pump 17 are respectively connected to a screw connector 3. The left end of the left screw connector 3 is connected to the right end of the left connecting screw 6, and the right end of the right screw connector 3 is connected to the left end of the right connecting screw 6.

[0040] See Figure 12 The working principle of this embodiment is the same as that of embodiment 1. When the excitation frequency of the AC drive power supply U1 is close to the anti-phase bending resonance frequency of the piezoelectric actuator, the piezoelectric actuator will generate a large-amplitude periodic vibration in the anti-phase bending resonance mode, thereby driving three sets of dual-cavity diaphragm pumps to continuously pump fluid at the same resonance frequency.

[0041] Similarly, by increasing the number of intermediate drive arms and simultaneously increasing the length of the crossbeam, a comb-finger resonator with more dual-chamber diaphragm pump assembly positions can be manufactured. By setting connecting screws 6 on each intermediate drive arm and configuring a corresponding number of dual-chamber diaphragm pumps, and by configuring screw connectors 3 on both sides of the power input end and connecting them in series through connecting screws 6, this comb-finger resonator can simultaneously drive more dual-chamber diaphragm pumps to work synchronously at the anti-phase resonant frequency, thereby forming piezoelectric wafer pumps with different pumping capacities.

[0042] The above description is merely a preferred embodiment of the present invention and is not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A piezoelectric wafer pump, comprising a piezoelectric actuator and multiple sets of dual-chamber diaphragm pumps driven therefrom, characterized in that: The piezoelectric actuator includes a comb-finger resonator, a bolt connector, and a screw connector. The comb-finger resonator includes a crossbeam and several drive arms that are vertically fixed on the top surface of the crossbeam and are equidistantly distributed. The bolt connector is located on the outermost drive arm, and the screw connector is located on the inner drive arm. The dual-chamber diaphragm pump is located between two adjacent drive arms and suspended above the top surface of the crossbeam. One power input end of the dual-chamber diaphragm pump is fixedly connected to a screw connector, and the other end is fixedly connected to a bolt connector or screw connector. The two adjacent dual-chamber diaphragm pumps have opposite working phases and the same resonant frequency. Pairs of piezoelectric plates are horizontally arranged on the top and bottom surfaces of the crossbeam, corresponding to each dual-chamber diaphragm pump directly below it. Pairs of piezoelectric plates are vertically arranged at the bottom ends of both sides of the drive arm. All piezoelectric plates are connected in series or in parallel. When the excitation frequency of the AC power applied to the piezoelectric plate is the inverse bending resonant frequency of the piezoelectric actuator, the comb-finger resonator simultaneously drives multiple sets of dual-cavity diaphragm pumps to continuously pump fluid at the same resonant frequency.

2. The piezoelectric wafer pump according to claim 1, characterized in that: The drive arm has a vertically oriented waist-shaped hole, and a connecting bolt or connecting screw is installed in the waist-shaped hole. The end of the bolt connector away from the dual-chamber diaphragm pump is threadedly connected to the connecting bolt, and the end of the screw connector away from the dual-chamber diaphragm pump is fixedly connected to the end of the connecting screw by a first bolt.

3. The piezoelectric wafer pump according to claim 2, characterized in that: The connecting screw has an external thread section in the middle, and two nuts are threaded onto the external thread section. The two nuts are located on both sides of the waist-shaped hole of the drive arm. Bosses are provided at both ends of the connecting screw, and lateral through holes are provided at the bosses. The first bolt passes through the lateral through holes and is threaded to the end of the screw connector.

4. The piezoelectric wafer pump according to claim 1, characterized in that: A mass block is fixedly installed at the top of the drive arm, located on the top side of the dual-chamber diaphragm pump, and an additional mass block is fixedly connected to the top of the mass block.

5. The piezoelectric wafer pump according to claim 4, characterized in that: The crossbeam, drive arm, and mass block are integrally formed.

6. The piezoelectric wafer pump according to any one of claims 1 to 5, characterized in that: The drive arm has a width of 5-100mm, a thickness of 0.5-5mm, and a length of 10-100mm. The crossbeam has the same width as the drive arm, a thickness of 0.5-5mm, and a length equal to the distance between the outermost two drive arms.

7. The piezoelectric wafer pump according to claim 6, characterized in that: The piezoelectric sheet is made of piezoelectric ceramic or piezoelectric single crystal, with a thickness of 0.01 to 1 mm, a width the same as the width of the drive arm / beam, and a length of 1 to 50 mm.

8. The piezoelectric wafer pump according to any one of claims 1 to 5 or 7, characterized in that: The comb-finger resonator is made of metal, and its surface, except for the area in contact with the piezoelectric element, is coated with an insulating layer.

9. The piezoelectric wafer pump according to any one of claims 1 to 5 or 7, characterized in that: The dual-chamber diaphragm pump is stacked and consists of two diaphragm pumps fixed back to back.

10. The piezoelectric wafer pump according to claim 9, characterized in that: The fluid channels of the two diaphragm pumps in each set of dual-chamber diaphragm pumps are connected in parallel or in series, and the fluid channels of each set of dual-chamber diaphragm pumps are connected in parallel or in series.

Images