Multiple jet piezoelectric pump

Abstract

A new piezoelectric pump driven by fluid, through the simulation and test of piezoelectric drive jet pump, a large flow multiple jet piezoelectric pump is obtained.

Description

Technical Field

[0001] A novel piezoelectric pump for driving fluids was developed. Through simulation and experimentation of a piezoelectric-driven jet pump, a high-flow-rate multi-jet piezoelectric pump was obtained. Background Technology

[0002] In the design of jet pumps such as piezoelectric pumps, the piezoelectric micro blower designed by CN101542122A, i.e., a piezoelectrically driven gas jet pump, is an example. Figure 5 (The original appendix to CN101542122A) Figure 1 As shown in the diagram. The piezoelectric actuator, piezoelectric ceramic 1, under the drive of an alternating signal, bends and deforms vertically, driving air to periodically increase or decrease the volume of the pump chamber, generating large positive or negative pressure within the pump chamber. During the positive pressure period, the fluid (such as air) inside the pump chamber is ejected at high speed from the small jet hole at the center of the upper wall of the pump chamber, forming a cylindrical high-speed fluid jet. After passing through the partition, it flows out through the corresponding small jet hole in the pump casing (such as...). Figure 5 (As indicated by d in the diagram). During the negative pressure period, fluid (such as air) in the partition is drawn into the pump cavity through the small jet holes on the upper wall of the pump cavity (such as...). Figure 5 (As shown in b in the diagram). This results in a fluid jet pump without backflow, eliminating the need for a check valve. This avoids the persistent backflow problem inherent in traditional designs. Summary of the Invention

[0003] Current technology has a relatively low flow rate, approximately 0.6 to 0.8 liters per minute, which is insufficient for applications. Although some improved designs, such as prior applications filed by the applicant alone or jointly with other parties, have significantly increased the flow rate, they still cannot meet actual needs.

[0004] In the simulation study of fluid motion, the fluid motion of the pump was analyzed, and actual sample preparation experiments were conducted. This led to the discovery of a superior and novel jet structure that significantly improves fluid drive efficiency, such as... Figure 1 . Figure 1 In this design, a jet baffle 11 and jet holes 12 on the baffle 11 are incorporated. The air intake baffle 7 is divided into upper and lower layers (7.1 and 7.2), achieving multiple jets. This effectively controls the orderliness of fluid movement and significantly reduces resistance factors such as turbulence. Furthermore, the Bernoulli effect of high-speed jets is introduced to expand the flow and increase the flow rate, thus increasing the actual flow rate by approximately 3 times, while the pump's energy consumption, i.e., power, remains unchanged at around 0.2 watts.

[0005] In existing technologies, such as Figure 5As shown in section

[0011] of the specification of CN101542122A, it is stated that when the pump cavity jet passes through the inflow channel 7 (equivalent to the air inlet baffle 7 in this application) at high speed, "because the high-speed flow entrains the fluid inflow channel 7 while flowing upward, a large flow rate can be obtained on the opening side of the second opening 5b." However, in reality, due to the hysteresis effect of the pump cavity air intake and the interference of turbulence and other factors, the superposition of various factors means that although the design of CN101542122A achieves effective isolation between the air intake and the air outlet and solves the "backflow" problem, the jet diffusion effect is not as expected or the effect is extremely limited. In this application, the pump cavity air intake and the diffusion jet use their own independent air inlet baffles, avoiding the aforementioned mutual interference, and the diffusion baffle is located in the upper layer, avoiding the turbulent region, achieving effective diffusion, and thus greatly improving efficiency. From another perspective, it can also be regarded as a diffusion effect with only a weak jet effect that is severely suppressed in the prior art. In this application, in addition to the weaker jet effect, the negative teaching of CN101542122A is overcome by superimposing a completely unrestrained and fully utilized (flow rate increased by 3 times) jet effect, and it is a double jet effect, which can even be extended to multiple N jets (N>=2).

[0006] Based on the experimental and simulation results, the air volume of the pump chamber is much smaller than that of the jet amplification air volume. Therefore, the thickness of the upper layer 7.2 of the air intake partition should be greater than the thickness of the lower layer 7.1 of the air intake partition. Attached Figure Description

[0007] Figure 1 A schematic cross-sectional view of the design in this application.

[0008] Figure 2 This is a design diagram showing that there are multiple jet holes 5 in the pump cavity, and multiple corresponding jet holes 12 on the partition plate 11, and multiple corresponding holes on the outer shell 8 to form the outlet 9.

[0009] Figure 3 This is a design diagram showing that there are multiple jet holes 5 in the pump cavity, multiple corresponding jet holes 12 on the partition plate 11, and a corresponding large hole on the outer shell 8 forming the outlet 9.

[0010] Figure 4 This is a schematic diagram showing that the partition 11 is smaller than the air intake partition.

[0011] Figure 5 It is a design based on existing technology, and is the original appendix to CN101542122A. Figure 1 .

[0012] In the diagram, 1 is the actuating component of the fluid pump made of piezoelectric ceramic or other actuating material; 2 is the gasket; 3 is the diaphragm; 1, 2, and 3 together form a piezoelectric resonator. 4 is the pump chamber; 5 is the second diaphragm; 6 is the pump chamber jet orifice formed by one or more holes on the second diaphragm; 7 is the air intake baffle, where the air intake baffle is divided into two layers, the lower layer being 7.1 and the upper layer being 7.2. 8 is the pump casing; 9 is the fluid outlet on the casing; 10 is the opening of the air intake baffle 7 or the upper and lower air intake baffles 7.1 and 7.2 on the side wall or near the outside of the pump, serving as the fluid inlet; 11 is the baffle separating the air intake baffles; and 12 is the jet orifice on the baffle 11. The electrodes and drive circuit of the drive signal are omitted and not shown. The drive signal can be a periodic or aperiodic signal, and its frequency can be the pump's resonant frequency. Detailed Implementation

[0013] With reference to the accompanying drawings, specific embodiments of this application are given, further elaborating on the design concept. Based on the mechanism proposed in this application, it can be applied to fluid pumps driven by various piezoelectric and other electromagnetic actuation materials without creative effort. Simply by mimicking the analysis in this application of using a baffle to divide the air intake layer into two layers and rationally arranging the fluid movement to achieve both a jet effect that separates the air intake and exhaust, and a jet amplification effect due to the Bernoulli effect, efficient jet fluid delivery can be achieved in various designs, including but not limited to the design of this application, as well as in fluid pumps driven by other actuation materials or machinery, resulting in a significant improvement in efficiency. In this application, up, down, left, and right are only relative directional concepts for ease of description; actual directional changes do not affect the design of this application. Example 1

[0014] exist Figure 1In the pump chamber 4, an electromagnetic actuator 1, made of piezoelectric or other materials, bends and deforms under the influence of electrical and / or magnetic signals, causing the gasket 2 and diaphragm 3 to bend and deform together. The deformation of the oscillator causes a significant change in the internal volume of the pump chamber 4, creating a large positive or negative pressure. The jet orifice of the pump chamber is located near the center of the pump. During pump operation, in the intake phase, fluid such as air is drawn in through the jet orifice of the pump chamber through the lower layer 7.1 of the intake partition, while outside air is replenished into the intake partition from the inlet 10. In the exhaust phase, the high-pressure fluid such as air in the pump chamber is ejected at high speed through the jet orifice 6 of the pump chamber, passing through the upper and lower intake partitions and flowing out to the outside through the outlet 9. When the high-speed jet enters the upper intake partition 7.2 through the jet orifice 12 of the partition 11, due to the high jet velocity, the jet effect or Bernoulli effect is triggered, carrying and attracting a large amount of fluid such as air from the intake partition 7.2, which flows out to the outside through the outlet 9 of the outer casing 8. Therefore, it can be seen that the two intake baffles 7.1 and 7.2 have different functions: intake baffle 7.1 is mainly used to separate the intake and exhaust air, reduce "backflow," and provide a gas source for the pump chamber. Intake baffle 7.2, on the other hand, is used for "flow amplification," increasing the flow rate and acting as a jet amplification baffle. Experiments have shown that the thickness of the upper layer of the intake baffle, i.e., the distance between the intake baffle and the pump casing, should preferably be greater than the thickness of the lower layer of the intake baffle, i.e., the distance between the baffle and the second diaphragm. Furthermore, the thickness of the upper layer 7.2 of the intake baffle, i.e., the distance between the intake baffle and the pump casing, is preferably 1 / 20 to 1 / 3 of the pump's operating frequency wavelength. At an operating frequency of approximately 25kHz, the thickness of the upper layer 7.2 of the intake baffle is in the range of 0.5 to 5 mm, preferably in the range of 0.8 to 4 mm, and even more preferably in the range of 1 to 3 mm. The thickness of the lower layer 7.1 of the intake baffle is preferably around 0.2 to 1.5 mm. The thickness ratio of the upper and lower layers of the air intake layer is approximately 1 to 6 times, and the thickness of the upper layer is preferably greater than or equal to the thickness of the lower layer.

[0015] However, as a degraded design, the thickness of the upper layer of the intake baffle can be made smaller than that of the lower layer. This reduces performance, but still results in two jet effects, and the pump flow rate is still significantly improved compared to existing technologies.

[0016] The openings of the air intake diaphragm and the fluid inlet of the pump can be located on the sidewall, or structurally directed to the upper and / or lower surface of the pump or any other location. Example 2

[0017] like Figure 4As shown, an air intake baffle 11, smaller than the air intake baffle layer, is provided between the pump housing and the second diaphragm. The baffle has jet holes 12. The outer diameter of the air intake baffle is preferably less than half the outer diameter of the air intake baffle layer, ensuring that the air intake of the upper and lower layers near the jet holes 12 does not interfere with each other. The outer air intake baffle layer is formed by merging the two separated layers into one, thus reducing the fluid flow resistance of the intake air and improving efficiency. As a special case, the air intake baffle in this example can be completely omitted. The air intake baffle layer is a single layer with a thickness of 1.0~5.0 mm, preferably 1.5~3.5 mm, more preferably 2.0~3.0 mm, or between 1 / 12 and 1 / 3 of the pump's operating frequency wavelength. The fluid movement itself divides the pump chamber into two zones: pump chamber air intake and jet diffusion. The fluid in the lower part of the air intake baffle layer 7, near the pump chamber jet holes (the lower half of the air intake baffle layer near the second diaphragm), provides the pump chamber air intake. The fluid in the upper part of the intake baffle 7 (the upper half of the intake baffle away from the second diaphragm) is attracted and entrained by the high-speed jet of the pump chamber due to the jet effect, and flows out of the outlet 9 together with the pump chamber jet, forming an effective "flow expansion". However, due to the mutual interference of the two intake movements, the pump flow rate will be slightly reduced, but it is still about twice that of the existing technology.

[0018] In the experiment, the piezoelectric pump designed in this application, under the same driving conditions, increased the flow rate by approximately three times compared to the prior art comparative sample. Specifically, the flow rate of the prior art comparative sample was 0.5 L / min, while the flow rate of the sample prepared using the design in this application was 1.6 L / min, an increase of 3.2 times. In another design scheme, the flow rate of the prior art dual-oscillator sample was 2.0 L / min, while the flow rate of the dual-oscillator sample designed in this application was 5.3 L / min, an increase of approximately 2.6 times. Power consumption remained largely unchanged.

[0019] In the design of this application, the jet orifice of the pump cavity can be as follows: Figure 1 , Figure 2 , Figure 3 and Figure 4As shown, a single hole at the center of the pump or multiple holes distributed around the center of the pump can be used. The shape of the hole can be various shapes, such as circular holes and / or arc-shaped holes, or any combination of hole type and / or hole distribution. The jet hole 12 on the inlet baffle 11 can be a larger circular hole (or a hole type with a similar shape to the jet hole of the pump chamber) aligned with the center of each jet hole of the pump chamber, or it can be a larger circular hole or other shape hole surrounding all the jet holes of the pump chamber, so that the jet of each jet hole of the pump chamber flows into the jet hole 12. Similarly, the outlet 9 of the pump casing 8 is set according to the same principle. The outlet, which consists of one or more holes, is larger than the jet hole 12 on the inlet baffle, aligned with and surrounding the jet hole 12, ensuring that the jet passing through the inlet baffle enters the range of the outlet 9. The outlet 9 is set to maximize the jet effect, that is, to ensure that enough fluid in the upper layer 7.2 of the inlet baffle is driven and attracted by the jet, flows out of the pump casing, and forms the maximum pump flow rate or the optimal flow rate required by the design. The shape, size, and position of the jet orifice and outlet 9 can be optimized through simulation and experimentation without requiring creative labor.

[0020] As a special case, in certain application scenarios, it can be omitted. Figures 1-4 Instead of the pump housing 8 and outlet 9 in the traditional sense, the outlet 9 is set on the outer casing of the entire device, such as a mobile phone, which uses a multi-jet piezoelectric pump. A positioning feature is also provided on the outer casing, allowing the pump to achieve [the desired effect] after installation. Figures 1-4 The complete design. At this point, a portion of the machine casing serves as the pump casing 8 and has an outlet 9. The lower part of the machine casing forms the air intake baffle 7.2, and the outlet 9 is aligned with and surrounds the jet hole 12 of the baffle 11. This significantly reduces the installation thickness.

[0021] The core technology of this application lies in the jet fluid pump driven by piezoelectric materials and other electromagnetic actuation materials. Based on fluid dynamics analysis and insights, it analyzes fluid motion through simulation, overcoming the erroneous teachings of existing technologies regarding jets. Through multi-jet design and experimentation, it achieves a significant flow expansion effect. The lower layer of the air inlet baffle provides air intake to the pump chamber, while the upper layer utilizes the high-speed jet effect to achieve flow expansion, resulting in a substantial increase in flow rate. This leads to a new multi-jet jet pump design, achieving significant technological advancements and benefits. This design can be applied to the design of other jet pumps without requiring creative labor or overcoming any biases, such as pumps driven by any actuation material, including mechanically driven pumps. Simply add a new outlet at the outlet of the existing pump, aligning with and surrounding the original outlet. The original outlet then becomes the jet hole 12 on the baffle 11 in this design. The new outlet and the partition separating the original outlet form the air inlet baffle 7.2 of this design. This achieves a significant flow expansion Bernoulli effect, greatly increasing the pump's flow rate. Only a sufficiently high fluid velocity at the original pump outlet is required. Furthermore, the pump's flow rate, maximum pressure, and other parameters can be adjusted according to actual needs to meet those needs.

[0022] This application can employ any existing or future piezoelectric oscillator design. The three-layer oscillator described in this application is merely an illustrative example to understand the design principles and concepts. This application can also employ a dual-crystal oscillator or a dual-oscillator (with a second oscillator replacing...) Figures 1-4 The system includes a second diaphragm and a piezoelectric material oscillator. Additionally, the intake baffle can be multi-layered, for example, with two layers, effectively dividing the intake baffle into three layers. The bottom layer is the pump chamber intake baffle, while the top two layers achieve jet amplification through two Bernoulli effects, resulting in multiple jet amplification processes.

[0023] The design of this application is supported by simulation and experimental verification, and has achieved significant technological progress and benefits, and has yielded a completely new design for a jet pump.

Claims

1. A multi-jet piezoelectric pump, comprising an oscillator composed of piezoelectric material and metal, a second diaphragm, the second diaphragm and the oscillator being spaced apart at a certain height to form a sealed pump chamber, a pump casing and at least one baffle plate being respectively disposed on the second diaphragm at a certain height, at least two upper and lower air inlet baffles being formed between the pump casing and the baffle plate, and between the baffle plate and the second diaphragm, one or more pump chamber jet holes being disposed on the second diaphragm to connect the pump chamber and the air inlet baffles, one or more jet holes being disposed on the baffle plate corresponding to the positions of the pump chamber jet holes, a fluid outlet being disposed on the pump casing, the outlet corresponding to and surrounding the jet holes of the baffle plate and the pump chamber, and a fluid inlet being disposed on the air inlet baffles, characterized in that, At least one baffle is provided between the pump housing and the second diaphragm, and the air intake baffle has at least two layers, upper and lower.

2. The multi-jet piezoelectric pump according to claim 1, further characterized in that, The lower layer of the intake baffle provides the fluid source for the pump chamber intake, while the upper layer of the intake baffle provides the fluid source for the high-speed jet effect.

3. The multi-jet piezoelectric pump according to claim 1, characterized in that, The outer diameter of the intake baffle is smaller than the diameter of the intake baffle layer.

4. The multi-jet piezoelectric pump according to claim 1, further characterized in that, The height or thickness of the upper layer of the air intake partition is greater than the height or thickness of the lower layer of the air intake partition.

5. The multi-jet piezoelectric pump according to claim 1, characterized in that, The upper layer height or thickness of the intake partition is greater than or equal to 0.5 mm, or between 1 / 20 and 1 / 3 of the pump's operating frequency wavelength.

6. The multi-jet piezoelectric pump according to claim 1, characterized in that, The pump housing is partially installed within the casing of the entire unit that uses the multi-jet piezoelectric pump, and the pump outlet is located in this partial area of ​​the casing to reduce the installation thickness.

7. The multi-jet piezoelectric pump according to claim 1, characterized in that, The baffle in the intake baffle can be omitted. The thickness of the intake baffle is greater than or equal to 1 mm, or between 1 / 12 and 1 / 3 of the wavelength of the pump's operating frequency. The fluid in the upper part or upper half of the intake baffle flows out of the outlet along with the pump cavity jet due to the jet effect.

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