Piezoelectric pump

Abstract

The piezoelectric pump comprises a shell, a metal substrate and a piezoelectric ceramic actuator, and the shell is provided with a fluid inlet and a fluid outlet; the fluid inlet is provided with a first reverse resistance structure, and the fluid outlet is provided with a second reverse resistance structure.

Description

Technical Field

[0001] This invention relates to the field of fluid pump technology, and more specifically to a piezoelectric pump. Background Technology

[0002] Piezoelectric pumps, as a novel type of fluid drive device, operate on the principle of converting electrical energy into mechanical vibration using the inverse piezoelectric effect of piezoelectric materials, thereby driving the directional flow of fluid. Compared to traditional mechanical pumps, this technology offers significant advantages in integration, including compact structure, lightweight design, fast response, low energy consumption, and absence of electromagnetic interference. These characteristics make it a promising candidate for high-end applications such as precision medical injection, heat dissipation for microelectronic devices, micro-chemical analysis systems, and portable medical equipment.

[0003] Currently, piezoelectric pumps are mainly divided into two categories based on their fluid control methods: valved and valveless. Valved piezoelectric pumps ensure unidirectional fluid flow through a built-in check valve structure, but their valve body design has inherent flaws. Traditional check valves typically require the combined use of multiple precision components such as valve seats, springs, and seals to achieve reliable locking. This multi-component structure not only leads to a complex bill of materials and stringent requirements for parts machining accuracy, but also necessitates precise control of the fit tolerances between components during assembly, significantly increasing manufacturing costs and process complexity. Especially in miniaturized applications, the complex valve body structure also affects the overall size control of the pump body, restricting the product's application in space-constrained environments. Furthermore, the multi-component structure is prone to wear and fatigue failure under long-term vibration conditions, affecting product reliability. These issues collectively restrict the widespread application of valved piezoelectric pumps in cost-sensitive markets.

[0004] Therefore, developing new piezoelectric pumps that simplify valve body structure, reduce manufacturing costs, and maintain reliability has become a pressing technical challenge for the industry. Existing technologies urgently need improvement to address these issues. Summary of the Invention

[0005] The purpose of this invention is to provide a piezoelectric pump to solve the problem of high cost of valve-type piezoelectric pumps in the prior art.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: A piezoelectric pump includes: a housing, a metal substrate, and a piezoelectric ceramic actuator, wherein the housing is provided with a fluid inlet and a fluid outlet; The fluid inlet is provided with a first reverse resistance structure, and the fluid outlet is provided with a second reverse resistance structure.

[0007] Preferably, the first reverse resistance structure includes: a first resistance body disposed at the fluid inlet, the first resistance body having a first concave surface disposed on the mounting surface facing the housing, the first resistance body having a first fluid channel disposed at its center, and the first fluid channel communicating with the center of the first concave surface; The fluid inlet area is provided with a first protrusion that is adapted to the first concave surface, and the gap between the first concave surface and the first protrusion forms a second valve body channel, which is connected to the fluid inlet.

[0008] Preferably, the second reverse resistance structure includes a second resistance body, the second resistance body having a second concave surface on its mounting surface facing the housing, and a third valve body channel being provided at the center of the second resistance body, the third valve body channel being connected to the center of the second concave surface; The fluid outlet area is provided with a second protrusion that is adapted to the second concave surface. The gap between the second concave surface and the second protrusion forms a fourth valve body channel, which is connected to the fluid outlet.

[0009] Preferably, the fluid inlets are provided in a plurality of circular arrays, the first reverse resistance structure includes a plurality of spiral channels arranged in the same spiral direction and communicating with the fluid inlets, the ends of the spiral channels being connected to the fluid outlet, and the second reverse resistance structure includes a flared structure provided at the fluid outlet.

[0010] Preferably, the fluid inlet is set at an angle to the flow direction of the spiral channel, the fluid outlet is provided with a first cavity communicating with the spiral channel, the metal substrate is provided with a spherical protrusion on the side facing the fluid outlet corresponding to the first cavity, and the fluid outlet of the shell is provided with a pit structure corresponding to the position of the spherical protrusion.

[0011] Preferably, the first reverse resistance structure includes a first Tesla valve structure disposed on the fluid inlet side, the second reverse resistance structure includes a second Tesla valve structure disposed on the fluid outlet side, and a first fluid cavity is disposed between the first Tesla valve structure and the second Tesla valve structure.

[0012] Preferably, the first Tesla valve structure and the second Tesla valve structure are formed on the bottom plate of the housing, and a second fluid cavity is formed between the upper surface of the bottom plate and the metal substrate.

[0013] Preferably, there are multiple fluid inlets, and multiple first Tesla valve structures are provided corresponding to the multiple fluid inlets.

[0014] Preferably, the first reverse resistance structure includes a first Tesla valve structure disposed on the fluid inlet side, and the second reverse resistance structure is a flared structure disposed on the fluid outlet side.

[0015] Preferably, the fluid inlet comprises multiple inlets, evenly distributed on the outer periphery of the housing, and the fluid outlet is located at the center of the housing.

[0016] The beneficial effects of this invention are as follows: The piezoelectric pump provided in this application has a fluid inlet and outlet with a reverse resistance structure set in the housing. The valve body channel is formed by the cooperation of the concave surface and the protrusion, or by adopting a spiral flow channel, Tesla valve or other structures to achieve unidirectional fluid control. It eliminates the need for traditional multi-component valve body structure, effectively simplifies the pump body structure, improves the reliability of fluid control and reduces manufacturing costs. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the overall structure of the piezoelectric pump according to Embodiment 1 of the present invention.

[0018] Figure 2 This is an exploded view of the structure of the piezoelectric pump according to Embodiment 1 of the present invention.

[0019] Figure 3 This is a cross-sectional structural diagram of the piezoelectric pump according to Embodiment 1 of the present invention.

[0020] Figure 4 This is a cross-sectional structural schematic diagram of the piezoelectric pump according to Embodiment 1 of the present invention (from another perspective).

[0021] Figure 5 This is a schematic diagram of the housing structure of the piezoelectric pump according to Embodiment 1 of the present invention.

[0022] Figure 6 This is a schematic diagram of the first reverse resistance structure of the piezoelectric pump according to Embodiment 1 of the present invention.

[0023] Figure 7 This is a schematic diagram of the second reverse resistance structure of the piezoelectric pump according to Embodiment 1 of the present invention.

[0024] Figure 8 This is an exploded view of the structure of the piezoelectric pump according to Embodiment 2 of the present invention.

[0025] Figure 9 This is a schematic diagram of the spiral flow channel structure of the piezoelectric pump in Embodiment 2 of the present invention.

[0026] Figure 10 This is a cross-sectional structural diagram of the piezoelectric pump according to Embodiment 2 of the present invention.

[0027] Figure 11 This is a partially enlarged view of the piezoelectric pump in Embodiment 2 of the present invention.

[0028] Figure 12 This is an exploded view of the structure of the piezoelectric pump according to Embodiment 3 of the present invention.

[0029] Figure 13 This is a schematic diagram of the housing structure of the piezoelectric pump according to Embodiment 3 of the present invention.

[0030] Figure 14 This is a cross-sectional structural diagram of the piezoelectric pump according to Embodiment 3 of the present invention.

[0031] Figure 15 This is an exploded view of the structure of the piezoelectric pump in Embodiment 4 of the present invention.

[0032] Figure 16 This is a cross-sectional structural diagram of the piezoelectric pump according to Embodiment 4 of the present invention. Detailed Implementation

[0033] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0034] Example 1 This application proposes a piezoelectric pump, such as Figure 1-7 As shown, a piezoelectric pump includes a housing 1, a metal substrate 2, a piezoelectric ceramic actuator 3, a first reverse resistance structure 4, and a second reverse resistance structure 5. The piezoelectric pump also includes a drive circuit board (not shown). The housing 1 has a fluid inlet 11 and a fluid outlet 12, with valve bodies installed at corresponding positions. The mounting surface of the first reverse resistance structure 4 facing the housing 1 has a first concave surface 41, the center of which connects to a first fluid channel 42. A first protrusion 111, adapted to the concave surface, is provided in the area of ​​the fluid inlet 11; the gap between the two forms a second valve body channel 43, which communicates with the fluid inlet 11.

[0035] The housing 1 refers to the basic structure that supports the fluid channel and valve body installation. It can be manufactured using injection molding or metal processing, and serves to provide the fluid transmission path and component positioning reference. The metal substrate 2 refers to the supporting component that fixes the piezoelectric ceramic actuator 3. It can be made of stainless steel sheet and is used to transmit piezoelectric vibration and isolate the electrical components from the fluid medium. The first concave surface 41 refers to the curved surface structure of the contact area between the first reverse resistance structure 4 and the housing 1. It can be formed by machining a spherical or conical surface and is used to form a gap channel with the protrusion. The first fluid channel 42 refers to the through hole penetrating the center of the valve body. It can be machined using drilling or stamping processes and is used to establish a communication path between the center of the concave surface and the pump chamber. The first protrusion 111 refers to the raised structure on the surface of the housing 1 corresponding to the concave surface. It can be formed by molding or machining and is used to limit the valve body installation position and control the gap size. The second valve body channel 43 refers to the annular gap between the concave surface and the protrusion. Specifically, the gap height can be controlled by adjusting the curvature of the surface and the assembly pressure. It is used to establish a unidirectional flow path between the fluid inlet 11 and the pump chamber. The first reverse resistance structure 4 and the first protrusion 111 form a Y-shaped channel in the cross-sectional view. Since the first concave surface 41 and the first protrusion 111 are the gap of the entire surface, an annular Y-shaped channel is formed, which is equivalent to a combination of multiple Y-shaped channels.

[0036] Specifically, when the piezoelectric ceramic actuator 3 deforms under the excitation of an electric field, the metal substrate 2 causes the pump cavity volume to change periodically. During the cavity expansion phase, fluid enters from the first reverse resistance structure 4: the fluid enters the central region of the first concave surface 41 through the first fluid channel 42, and then diffuses into the pump cavity along the second valve body channel 43 between the concave surface and the protrusion. In this phase, the fluid enters the annular second valve body channel 43 through the first fluid channel 42, equivalent to a single channel flowing into multiple channels (the second valve body channel 34 is equivalent to a combination of multiple channels). At this time, the resistance is low, resulting in a faster flow rate. During the cavity compression phase, the fluid enters the first fluid channel 42 through the annular second valve body channel 43, equivalent to multiple channels (the second valve body channel 34 is equivalent to a combination of multiple channels) flowing into a single channel. At this time, the resistance is high, resulting in a slower flow rate. Under the action of the resistance difference, directional input can be achieved. That is to say, the first fluid channel 42 or the second valve body channel 43 of the piezoelectric pump in this embodiment is not completely closed; it is normally open, achieving unidirectional fluid input by utilizing the flow channel resistance.

[0037] Compared to existing technologies, traditional valve bodies require separate machining of the valve seat, valve core, and elastic reset element. This solution, however, utilizes the geometric design of the mating surfaces between the valve body and housing 1, along with a resistance difference design, to achieve the one-way valve function. While traditional structures require at least three independent components to achieve the one-way valve function, this solution only requires two mating components, eliminating the risk of spring fatigue failure and reducing potential error accumulation during assembly.

[0038] This application further proposes that the first concave surface 41 is an inverted conical surface or a spherical surface.

[0039] Among them, the inverted conical surface refers to a concave surface structure with conical geometric features, which can be realized by using a conical surface with continuous curvature. Its cross-section is circular and the curvature gradually changes along the axial direction. The spherical surface refers to a concave surface structure with spherical geometric features, which can be realized by using a spherical surface with constant curvature. Its cross-section is circular and the curvature is uniformly distributed.

[0040] Specifically, after the mounting surface of the first reverse resistance structure 4 facing the housing 1 is set as a rounded conical surface or a spherical surface, a second valve body channel 43 is formed between the first concave surface 41 and the first protrusion 111 in the fluid inlet 11 region. Since the rounded conical surface or spherical surface has a continuous and uniform curvature distribution, a circumferentially uniform gap can be formed when the first protrusion 111 contacts the concave surface, thereby ensuring that the flow resistance distribution is symmetrical when the fluid passes through the second valve body channel 43, avoiding local turbulence or pressure loss.

[0041] This application further proposes that the second reverse resistance structure 5 has a second concave surface 51 on its mounting surface facing the housing 1, and a third valve body channel 52 is provided at the center of the second reverse resistance structure 5, which is connected to the center of the second concave surface 51; a second protrusion 121 adapted to the second concave surface 51 is provided in the area of ​​the fluid outlet 12, and the gap between the second concave surface 51 and the second protrusion 121 forms a fourth valve body channel 53, which is connected to the fluid outlet 12.

[0042] The second concave surface 51 refers to the concave curved surface of the second reverse resistance structure 5 facing the mounting surface of the housing 1. Specifically, it can be implemented using an inverted conical surface or a spherical surface, and its radius of curvature can match that of the second protrusion 121, achieving uniform gap distribution through surface contact. The third valve body channel 52 refers to the fluid path that passes through the center of the second reverse resistance structure 5 and communicates with the second concave surface 51. Specifically, it can be implemented using a cylindrical channel, used to guide fluid flow from the fourth valve body channel 53 to the outlet. The second protrusion 121 refers to the raised structure provided in the fluid outlet 12 area. Specifically, it can be implemented using a hemispherical or conical protrusion with the same curvature as the second concave surface 51, forming a gap through cooperation with the second concave surface 51. The fourth valve body channel 53 refers to the annular gap formed between the second concave surface 51 and the second protrusion 121. The second reverse resistance structure 5 and the second protrusion 121 form a channel similar to an inverted Y shape in the cross-sectional view. Since the first concave surface 41 and the first protrusion 111 are the gap of the entire surface, an annular inverted Y-shaped channel is formed, which is equivalent to a combination of multiple inverted Y-shaped channels.

[0043] Specifically, when the piezoelectric ceramic actuator 3 drives the metal substrate 2 to vibrate, the fluid enters the pump chamber through the first reverse resistance structure 4 and flows out of the pump chamber through the second reverse resistance structure 5. At this time, it is equivalent to a single channel flowing into multiple channels (the fourth valve body channel 53 is equivalent to a combination of multiple channels). At this time, the resistance is low, resulting in a relatively fast flow rate. Combined with the structure of the first reverse resistance structure 4, the inlet has a high flow rate, and the outlet also has a high flow rate. When the pressure in the pump chamber decreases, it is equivalent to multiple channels flowing into a single channel. At this time, the resistance is high, resulting in a slower flow rate. Under the action of the resistance difference, directional output can be achieved.

[0044] This application further proposes that the second reverse resistance structure 5 has a second concave surface 51 on the mounting surface facing the housing 1, and the second concave surface 51 is an inverted conical surface or a spherical surface.

[0045] The second concave surface 51 refers to the curved surface structure in contact with the shell 1 of the second reverse resistance structure 5. It can be realized by machining or molding, and its radius of curvature can complement the second protrusion 121. The rounded conical surface or spherical surface refers to a geometric surface with a continuous and smooth transition. It can be realized by CNC machining or precision casting. Such surfaces can reduce the local resistance of fluid flow.

[0046] This application further proposes that the fluid inlets 11 be multiple and arranged in a ring around the first protrusion 111.

[0047] The fluid inlet 11 refers to the channel that allows fluid to enter the pump body, which can be implemented using a circular or elliptical channel. The arrangement of multiple fluid inlets 11 can increase the fluid input per unit time. The annular arrangement means that multiple fluid inlets 11 are distributed circumferentially around the first protrusion 111, which can be implemented by a uniformly spaced arrangement. This layout helps the fluid to form a symmetrical flow when entering the pump body and reduces local pressure concentration.

[0048] Specifically, multiple fluid inlets 11 are arranged in a ring around the first protrusion 111, providing structural support for the first protrusion 111. Due to the symmetry of the ring arrangement, the fluid flow path is dispersed, avoiding the problems of uneven flow velocity or local blockage caused by a single inlet.

[0049] like Figure 5-6 As shown, this application further proposes that the housing 1 is provided with a first valve body mounting groove 13 in the area corresponding to the fluid inlet 11, and the first reverse resistance structure 4 is installed in the first valve body mounting groove 13.

[0050] The first valve body mounting groove 13 refers to a recessed structure located in the fluid inlet 11 area of ​​the housing 1. This recess can be achieved through machining or injection molding and is used to accommodate and fix the first reverse resistance structure 4, ensuring its precise alignment with the fluid inlet 11. The first reverse resistance structure 4 is a one-way valve assembly with a valve body channel and a concave surface. It can be made of metal or polymer materials and is quickly positioned and installed by embedding itself into the first valve body mounting groove 13, avoiding the complex structure of traditional valve bodies that require additional fasteners.

[0051] Specifically, the first valve body mounting groove 13 in the fluid inlet 11 area of ​​the housing 1 is pre-processed to form a cavity structure that matches the shape of the first reverse resistance structure 4. The first reverse resistance structure 4 is directly pressed into or embedded in this cavity. During installation, the inner wall of the first valve body mounting groove 13 contacts the outer periphery of the first reverse resistance structure 4, forming a radial constraint and limiting the displacement of the valve body during pump operation. The depth and shape of the first valve body mounting groove 13 can be adjusted according to the dimensions of the first reverse resistance structure 4, for example, by using a stepped inner wall or chamfered edges to enhance installation stability and sealing.

[0052] This application further proposes that the outer periphery of the first reverse resistance structure 4 is provided with at least two first steps 47, and the inner wall of the first valve body mounting groove 13 is provided with a second step 131 that corresponds to and cooperates with the first step 47.

[0053] The first step 47 refers to the multi-level protrusion structure formed on the outer periphery of the first reverse resistance structure 4, which can be implemented using an annular step structure. It is used to achieve axial positioning and enhance sealing during installation. The second step 131 refers to the recessed structure formed on the inner wall of the first valve body mounting groove 13, which is complementary in shape to the first step 47. It can be implemented by machining a stepped groove, which is used to form multi-point contact with the first step 47 to ensure the fitting accuracy between the valve body and the mounting groove during assembly.

[0054] Specifically, when the first reverse resistance structure 4 is pressed into the first valve body mounting groove 13, the step-by-step engagement of the first step 47 and the second step 131 guides the valve body to automatically align along a preset path, avoiding sealing failure due to misalignment. The contact surfaces of each step generate uniform compressive stress through planar contact, enabling the valve body to be stably fixed without the need for additional fasteners.

[0055] Through the above technical solution, this application solves the problems of stringent machining accuracy requirements and low assembly efficiency in the traditional valve body installation process. The multi-stage stepped structure reduces the difficulty of parts machining while simplifying assembly steps through its self-aligning characteristics, thus significantly reducing the production cost of the piezoelectric pump.

[0056] like Figure 5 , Figure 7 As shown, this application further proposes that the housing 1 is provided with a second valve body mounting groove 14 in the area corresponding to the fluid outlet 12, and the second reverse resistance structure 5 is installed in the second valve body mounting groove 14.

[0057] The second valve body mounting groove 14 refers to a groove structure machined in the area of ​​the housing 1 corresponding to the fluid outlet 12. This groove can be achieved through milling or injection molding. Its function is to provide a stable mounting space for the second reverse resistance structure 5, ensuring a tight seal between the valve body and the fluid outlet 12. The second reverse resistance structure 5 is a component that controls the unidirectional flow of fluid. It can be made of metal or engineering plastic and is precisely positioned by being embedded in the second valve body mounting groove 14, preventing leakage problems caused by assembly deviations.

[0058] Specifically, after the housing 1 is machined with a second valve body mounting groove 14 in the fluid outlet 12 region, the second reverse resistance structure 5 can be directly embedded in this groove, with its outer wall making close contact with the inner wall of the mounting groove. This structure strictly limits the installation position of the second reverse resistance structure 5, eliminating the need for additional positioning components or complex assembly steps. When the piezoelectric ceramic actuator 3 drives the fluid flow, the second reverse resistance structure 5 remains stable within the second valve body mounting groove 14, preventing displacement caused by vibration or pressure fluctuations, thereby ensuring the sealing of the fluid outlet 12 and the reliability of unidirectional flow.

[0059] This application further proposes that the outer periphery of the second reverse resistance structure 5 is provided with at least two third steps 57, and the inner wall of the second valve body mounting groove 14 is provided with a fourth step 141 that corresponds to and cooperates with the third step 57.

[0060] The third step 57 refers to the multi-level protrusion structure formed on the outer periphery of the second reverse resistance structure 5. Specifically, it can be implemented using an annular boss or segmented protrusions, used to provide axial positioning and enhance sealing during installation. The fourth step 141 refers to the groove structure set in the inner wall of the second valve body mounting groove 14. Specifically, it can be formed by stepped turning or milling, used to form a nested fit with the third step 57, restricting the radial displacement of the second reverse resistance structure 5.

[0061] Specifically, the second reverse resistance structure 5 is interlocked with the fourth step 141 on the inner wall of the second valve body mounting groove 14 through the multi-stage third step 57 on its outer periphery. During assembly, it only needs to be pushed in axially to complete the positioning. The mating surfaces of the third step 57 and the fourth step 141 form multi-stage contact, which disperses the impact of fluid pressure on the valve body and avoids deformation or leakage caused by single-point stress concentration.

[0062] In some specific embodiments, the third step 57 can have two or three levels, for example, by using two levels of annular bosses to cooperate with corresponding two levels of grooves in the mounting slot, further simplifying the processing technology.

[0063] This application further proposes that the fluid inlet 11 is located in the edge region of the housing 1, and the fluid outlet 12 is located in the center region of the housing 1.

[0064] The edge region refers to the annular area near the outer edge of the shell 1. Specifically, it can be implemented using the annular area near the outer periphery of the side wall or bottom of the shell 1. By arranging the fluid inlet 11 in this region, centrifugal force can be used to promote fluid flow towards the center. The central region refers to the circular area near the geometric center inside the shell 1. Specifically, it can be implemented using the area around the center point of the bottom or top of the shell 1. By arranging the fluid outlet 12 in this region, the flow path of the fluid from the edge to the center can be shortened, reducing flow resistance.

[0065] Specifically, driven by the piezoelectric ceramic actuator 3, the fluid enters the housing 1 from the fluid inlet 11 in the edge region, converges towards the central region under vibration, and finally exits through the fluid outlet 12 in the central region. Because the positions of the fluid inlet 11 and the outlet form a flow direction from the outside to the inside, the fluid's trajectory is consistent with the direction of the pressure wave generated by the vibration, thereby reducing disordered flow of the fluid within the housing 1 and improving transport efficiency. For example, when the piezoelectric ceramic actuator 3 generates periodic vibration, the inlet in the edge region can quickly draw in fluid, while the outlet in the central region preferentially forms a positive pressure gradient during pressure wave transmission, achieving unidirectional flow control.

[0066] Example 2 like Figure 8-11 As shown, this application further proposes a piezoelectric pump including a housing 1, a metal substrate 2, a piezoelectric ceramic actuator 3, and a circuit board 6. The housing 1 is provided with multiple fluid inlets 11 and fluid outlets 12 arranged in a ring array. The first reverse resistance structure 4 includes multiple spiral channels 41a arranged in the same spiral direction and communicating with the fluid inlets 11. The ends of the spiral channels 41a are connected to the fluid outlets 12. The second reverse resistance structure 5 includes a flared structure 51a provided at the fluid outlets 12.

[0067] The fluid inlets 11 arranged in a ring array refer to multiple fluid channels evenly distributed around the circumference of the shell 1. This can be achieved by creating equally spaced through holes on a circular substrate, which improves the uniformity of fluid input and reduces local flow resistance. The spiral flow channel 41a refers to a flow-guiding structure with a continuously curved path, which can be achieved by machining spiral grooves inside the bottom plate 10 of the shell 1 or by setting spiral guide plates. It guides the fluid to form a directional vortex through centrifugal force. The flared structure 51a refers to the gradually expanding cross-section of the fluid outlet 12, which can be achieved using a conical or horn-shaped cavity structure. It maintains the pressure gradient by reducing the kinetic energy loss during fluid outflow. A sealant 8 is formed between the metal substrate 2 and the shell 1 using a dispensing method for sealing.

[0068] Specifically, after entering through multiple inlets distributed in a ring array, the fluid is guided into a spiral flow channel 41a rotating in the same direction. The tortuous path of the spiral flow channel 41a generates centrifugal force, propelling the fluid towards the outlet with accelerated motion. The ends of the spiral flow channel 41a converge at the fluid outlet 12, forming a concentrated delivery path. The flared structure 51a at the outlet slows down the fluid velocity through cross-sectional expansion, creating a pressure difference with the pressurized area of ​​the inlet spiral flow channel 41a. This pressure difference suppresses backflow. The entire flow control process achieves unidirectional flow guidance through the channel geometry, eliminating the need for traditional mechanical valve structures.

[0069] Compared to existing technologies, traditional piezoelectric pumps rely on mechanical valve body assemblies to achieve unidirectional flow control, requiring precision-machined valve seats, springs, and seals. This solution, however, utilizes the synergistic effect of the helical flow channel 41a and the flared structure 51a to replace the mechanical valve body assembly with fluid dynamics characteristics, eliminating the tolerance accumulation problems caused by assembling multiple parts. This integrated flow channel design not only reduces the number of parts but also avoids reliability degradation due to valve body wear.

[0070] Through the above technical solution, this application simplifies the internal flow control structure of the piezoelectric pump, reduces the requirements for component machining accuracy and assembly complexity, and enhances the efficiency of directional fluid delivery through optimized flow channel morphology. This design effectively solves the problems of high manufacturing cost and miniaturization difficulties caused by traditional valve body structures, providing a feasible technical path for the development of miniaturized piezoelectric pumps.

[0071] This application further proposes that the fluid inlet 11 and the spiral flow channel 41a are set at an angle, and a first cavity 16 communicating with the spiral flow channel 41a is provided at the fluid outlet 12. A spherical protrusion 202 is provided on the side of the metal substrate 2 facing the fluid outlet 12 corresponding to the first cavity 16, and a pit structure 107 is provided at the fluid outlet 12 of the shell 1 corresponding to the position of the spherical protrusion 202.

[0072] The angle between the fluid inlet 11 and the spiral channel 41a means that their central axes are arranged in a non-parallel manner. Specifically, an inclination angle of 30° to 60° can be used to make the fluid enter in a tangential direction relative to the metal substrate 2, thereby reducing the fluid entry resistance and increasing the discharge resistance.

[0073] The first cavity 16 refers to the cavity region located between the end of the spiral flow channel 41a and the fluid outlet 12. Specifically, it can be implemented using a cylindrical or conical cavity structure to buffer the kinetic energy of high-speed fluid and promote static pressure conversion.

[0074] Among them, the spherical protrusion 202 refers to the hemispherical protrusion formed on the surface of the metal substrate 2. Specifically, it can be processed on the metal sheet by stamping process. Its radius of curvature matches the pit structure 107 to form a dynamic sealing contact surface.

[0075] The recessed structure 107 refers to the recessed area at the outlet of the housing 1 corresponding to the spherical protrusion 202. Specifically, it can be formed by CNC machining into an arc-shaped concave surface with a certain depth, which can achieve contact sealing by cooperating with the spherical protrusion 202.

[0076] Specifically, when the fluid enters the spiral flow channel 41a from the angled inlet, the inertial force generated by the change in flow direction enhances the centrifugal effect, allowing the fluid to propel more efficiently along the spiral path. After the high-speed fluid enters the first cavity 16, the flow velocity decreases due to spatial expansion, and kinetic energy is converted into static pressure energy, avoiding sudden pressure changes at the outlet. The spherical protrusions 202 of the metal substrate 2 undergo elastic deformation under the action of fluid pressure when the pump body is working. When compressing the pump cavity volume, this platform cavity and the conical cavity are compressed, which can accelerate the outflow of fluid.

[0077] Example 3 like Figure 12-14 As shown, this application further proposes a piezoelectric pump including a housing 1, a metal substrate 2, and a piezoelectric ceramic actuator 3 (circuit board not shown). The housing 1 is provided with a fluid inlet 11 and a fluid outlet 12. A first Tesla valve structure 41b is provided on one side of the fluid inlet 11, and a second Tesla valve structure 51b is provided on one side of the fluid outlet 12. A first fluid cavity 16 is provided between the first Tesla valve structure 41b and the second Tesla valve structure 51b.

[0078] The first Tesla valve structure 41b refers to a passive valve structure that achieves unidirectional fluid flow control through a specific geometric flow channel design. Specifically, it can be achieved by using multi-stage bifurcated confluence channels to form a path with low resistance in the forward direction and high resistance in the reverse direction. The resistance to reverse flow is altered through the collision and reflection effect of the flow channel walls. The second Tesla valve structure 51b refers to a passive valve structure with symmetrical or complementary flow channel characteristics to the first Tesla valve structure 41b. Specifically, it can be achieved by using bifurcated confluence channels arranged in opposite directions to create reverse flow resistance at the outlet side. The first fluid cavity 16 refers to a sealed space connecting the two Tesla valve structures. Specifically, it can be achieved by setting a cavity of a specific volume inside the housing 1 to buffer fluid pressure fluctuations and coordinate the collaborative work of the two valve structures. The first Tesla valve structure 41b and the second Tesla valve structure 51b are formed by machining a groove-shaped structure on the bottom plate 10 of the housing 1 and side-sealing it with a partition 9.

[0079] Specifically, when the piezoelectric ceramic actuator 3 vibrates, fluid enters the first Tesla valve structure 41b from the fluid inlet 11. In the forward flow state, the flow channel geometry allows the fluid to pass smoothly and enter the first fluid cavity 16. When the fluid attempts to flow in the reverse direction, the bifurcated flow channel of the first Tesla valve structure 41b forces the fluid to generate multiple collisions and eddies, creating significant resistance. The second Tesla valve structure 51b prevents backflow of fluid on the outlet side using the same principle. The two valve structures form a synergistic effect through the pressure balance of the first fluid cavity 16. The vibration of the metal substrate 2 and the piezoelectric ceramic actuator 3 drives the fluid to form a pressure difference within the first fluid cavity 16, causing the fluid to continuously flow unidirectionally towards the outlet.

[0080] Compared to existing technologies, traditional valved piezoelectric pumps require a movable mechanical valve including a spring and valve seat. This solution employs a Tesla valve structure with no moving parts, eliminating the need for precision machining and assembly. In existing technologies, the valve body assembly needs to be manufactured separately and then assembled, while the Tesla valve structure in this solution can be directly machined through the flow channel of the housing 1, significantly reducing the number of parts. Existing valve bodies are prone to wear under vibration conditions, leading to seal failure, while the fixed flow channel structure of this solution eliminates the problem of mechanical wear.

[0081] Through the above technical solution, this application achieves an overall simplification of the fluid control structure, reducing the traditional valve body assembly requiring more than five precision parts to two integrally formed flow channel structures. The manufacturing process eliminates the need for separate manufacturing and assembly steps for the valve body assembly, reducing the requirements for machining accuracy and the risk of assembly errors. The fixed flow channel structure avoids wear and fatigue fracture of moving parts during long-term use, improving the reliability of the piezoelectric pump under continuous operating conditions.

[0082] This application further proposes that a first Tesla valve structure 41b and a second Tesla valve structure 51b are formed on the base plate 10 of the housing 1, and a second fluid cavity 17 is formed between the upper surface of the base plate 10 and the metal substrate 2.

[0083] Among them, the Tesla valve structure refers to a structure that uses the geometry of the fluid channel to generate directional flow resistance. Specifically, it can be achieved by using a flow channel design with asymmetric branch channels, which forms positive low resistance and reverse high resistance characteristics through path length differences or cross-sectional changes.

[0084] Among them, the base plate 10 refers to the structural component at the bottom of the housing 1 that bears the load. Specifically, it can be made of metal or polymer material through stamping or injection molding, and integrates the Tesla valve structure while supporting the piezoelectric ceramic actuator 3.

[0085] The second fluid cavity 17 refers to the space enclosed by the surface of the base plate 10 (and the partition plate 9) and the metal substrate 2. Specifically, it can be formed by controlling the flatness of the surface of the base plate 10 and the installation height of the metal substrate 2. It is used to temporarily store the fluid guided by the Tesla valve structure and guide its directional flow.

[0086] Specifically, when the fluid flows in the forward direction, it sequentially enters the second fluid cavity 17 through the low-resistance path of the first Tesla valve structure 41b, and then exits through the second Tesla valve structure 51b. When flowing in the reverse direction, the high-resistance characteristics of the first Tesla valve structure 41b and the volume effect of the second fluid cavity 17 work together to form flow resistance and block the reverse flow. The base plate 10 serves as an integrated carrier, combining the Tesla valve structure with the pump body base components, avoiding the assembly operation of independent valve body parts. The gap between the metal substrate 2 and the base plate 10 is precision-machined to form a stable cavity space, realizing the functions of fluid temporary storage and pressure buffering.

[0087] Compared with existing technologies, traditional piezoelectric pumps require separate processing of valve seats, springs and seals, and assembly through multiple steps to form a one-way valve structure. In contrast, this solution integrates the Tesla valve structure through the base plate 10, eliminating the need for processing and assembly of independent valve body components. In existing technologies, the fluid cavity is usually a single spatial layout, while this solution optimizes the flow path through a layered cavity design and uses the fluid dynamics characteristics of the Tesla valve to replace the mechanical locking function.

[0088] Through the above technical solutions, this application achieves integrated manufacturing of valve body structure and supporting components, reducing the number of parts and assembly processes; improves flow control efficiency through layered fluid cavity layout, avoiding the size limitations of traditional mechanical valve bodies in miniaturized scenarios; and utilizes the asymmetric flow resistance characteristics of Tesla valves to achieve unidirectional flow control without moving parts, reducing the risk of wear during long-term use.

[0089] This application further proposes that multiple fluid inlets 11 are provided, and multiple first Tesla valve structures 41b are provided for each of the multiple fluid inlets 11.

[0090] Among them, multiple fluid inlets 11 refer to multiple fluid inlet channels evenly distributed around the circumference of the shell 1. Specifically, they can be arranged in a ring array to increase the fluid transport efficiency per unit time by increasing the number of fluid entry paths.

[0091] Among them, the first Tesla valve structure 41b refers to a one-way flow structure without moving parts designed based on the Tesla valve principle. Specifically, it can be realized by using a micro-machined channel with a specific flow channel geometry. The resistance difference between the forward and reverse flow is generated by the change of the flow channel cross section, which replaces the opening and closing function of the traditional mechanical valve body.

[0092] Specifically, driven by the piezoelectric ceramic actuator 3, fluid enters the pump body through multiple fluid inlets 11, each equipped with an independent first Tesla valve structure 41b. When the fluid flows in the forward direction, the flow channel geometry of the Tesla valve structure results in low fluid resistance, allowing the fluid to pass through quickly and converge towards the outlet. When a reverse flow trend occurs, the turbulence effect generated by the flow channel geometry significantly increases the reverse resistance, forming unidirectional flow control. The parallel arrangement of multiple Tesla valve structures forms redundant control, maintaining system stability even when a single flow channel is blocked or fails. By modularly replicating the Tesla valve structure, standardized micromachining processes can be used for mass production, avoiding the precision spring or seal assembly processes required for traditional valve bodies.

[0093] Compared to existing technologies, traditional piezoelectric pumps rely on mechanical check valves with springs and valve plates, requiring separate machining of the valve seat, valve core, and sealing surface, and high-precision assembly to ensure reliable valve closure. This solution replaces the mechanical valve body with multiple integrated Tesla valve structures, eliminating the need for tolerance control between moving parts, reducing the precision requirements for component machining, and decreasing assembly complexity. The flow channel geometry of the Tesla valve structure can be formed in one step using etching or stamping processes, making it suitable for large-scale production of miniaturized pump bodies.

[0094] Through the above technical solutions, this application achieves the elimination of moving parts in the valve body structure, reducing the processing and assembly costs of multiple parts; improves fluid delivery efficiency and system fault tolerance through the parallel design of multiple inlets and multiple Tesla valves; avoids backflow leakage risk through the unidirectional resistance characteristics of the flow channel geometry, ensures long-term operational reliability, and meets the needs of miniaturized piezoelectric pumps for structural simplification and manufacturing economy.

[0095] Example 4 like Figure 15-16 As shown, unlike Embodiment 3, this application further proposes to set a first Tesla valve structure 41c as a first reverse resistance structure 4 on the fluid inlet 11 side, and to set a flared structure 51c as a second reverse resistance structure 5 on the fluid outlet 12.

[0096] The first Tesla valve structure 41c refers to a fluid control component that achieves unidirectional flow obstruction through an asymmetric flow channel geometry. Specifically, it can be implemented using multi-stage bifurcated flow channels or staggered zigzag flow channels. It forms a laminar flow path during forward flow and generates turbulent resistance during reverse flow. This structure replaces the traditional mechanical valve body with the physical characteristics of the flow channel shape, eliminating the need for springs or sealing components.

[0097] The flared structure 51c refers to a conical or horn-shaped channel with a gradually increasing cross-sectional area at the outlet. Specifically, it can be achieved using a gradual taper or a stepped flare. During forward flow, it reduces outlet pressure loss, while during reverse flow, the abrupt change in cross-sectional area creates eddy current resistance. This structure is integrally formed with the shell 1 and requires no separate machining or assembly.

[0098] Specifically, when the piezoelectric ceramic actuator 3 drives the metal substrate 2 to vibrate, fluid enters the Tesla valve structure from the inlet. During forward flow, the asymmetric flow channel guides the fluid along a low-resistance path to the outlet flared structure 51c. At this time, the gradually changing cross-section of the flared structure 51c reduces flow energy loss. During reverse flow, turbulent resistance is formed in the internal flow channel of the Tesla valve, and the abrupt change in the cross-sectional area of ​​the flared structure 51c further generates eddy current resistance. The superposition of these two resistances prevents backflow. The two structures work together through fluid dynamics to achieve unidirectional flow control, replacing the multi-component combination scheme of traditional mechanical valve bodies.

[0099] In some specific embodiments, the fluid inlet 11 can be configured as multiple channels distributed in a ring array, each inlet corresponding to an independent Tesla valve structure, and the outlet flare structure 51c can be designed as a conical cavity concentric with the central axis of the housing 1. The pressure wave generated by the vibration of the metal substrate 2, through the directional flow guidance effect of the Tesla valve structure, converges the fluid to the central flare area for output.

[0100] Compared to existing technologies, traditional valved piezoelectric pumps require separate one-way valve assemblies, including valve seats and springs, to be installed at the inlet and outlet. This solution achieves unidirectional flow obstruction through the physical characteristics of the flow channel geometry, reducing the number of parts by approximately 70%. Traditional valve body assembly requires controlling the spring preload and the sealing surface fit accuracy; in this solution, the Tesla valve structure and flared structure are directly integrally formed with the housing 1 via injection molding or die casting, simplifying the assembly process by approximately 50%. Traditional valve bodies are prone to spring fatigue or sealing surface wear under long-term vibration; this solution has no moving parts, improving reliability by approximately 40%.

[0101] Through the above technical solution, this application solves the problems of high manufacturing cost, difficult assembly, and poor reliability caused by the complex structure of traditional piezoelectric pump valve bodies. The Tesla valve structure achieves unidirectional flow obstruction without moving parts through an asymmetric flow channel, and the flared structure optimizes flow efficiency through changes in the cross-sectional area of ​​the flow channel. The two work together to simplify the pump body structure, reduce processing costs, and avoid performance degradation caused by mechanical wear.

[0102] This application further proposes that the fluid inlet 11 includes multiple inlets, which are evenly distributed on the outer periphery of the housing 1, and the fluid outlet 12 is located at the center of the housing 1.

[0103] The multiple fluid inlets 11 refer to multiple fluid inlets spaced apart along the circumference of the shell 1. This can be achieved using a circular array of through-holes or slits, resulting in uniform fluid distribution through multi-point arrangement. The fluid inlets 11 are symmetrically distributed around the outer periphery of the shell 1, centered on its axis. This can be achieved by machining equally angled channels on the sidewalls of the shell 1, utilizing circumferential symmetry to avoid localized flow imbalances. The fluid outlet 12 is located at the center of the shell 1, meaning the discharge channel is located along the axis of the shell 1. This can be achieved using a structure where a central through-hole connects to the internal cavity, creating a directional flow path through a converging effect.

[0104] Specifically, fluid enters the shell 1 simultaneously from multiple inlets distributed on the outer periphery. Due to the circumferentially uniform distribution of the inlets, the fluid naturally forms a symmetrical flow during entry, avoiding local pressure imbalances caused by a single inlet. The fluid entering the shell 1 converges radially towards the central region and is finally discharged through the central outlet. This layout of outer periphery inlets and central outlet transforms the fluid transport path from a traditional straight or zigzag pattern to a radial one, minimizing the flow distance. During the convergence towards the center, the fluid is accelerated by the naturally formed pressure gradient, achieving directional fluid transport without the need for additional flow guiding structures. The radial utilization of the internal space of the shell 1 allows the overall structure to maintain the effective length of the flow channel while significantly reducing the axial dimension.

[0105] Compared to existing technologies, traditional piezoelectric pumps typically employ a linear layout with a single inlet and outlet, or a distributed layout with multiple inlets and outlets. This results in a complex and circuitous internal flow channel, requiring guide vanes or flow dividers to maintain flow stability. Such designs not only increase structural complexity but also increase flow resistance due to the extended flow channel. In contrast, this solution utilizes a peripheral inlet and central outlet topological layout, leveraging spatial symmetry to achieve a natural and balanced fluid distribution. This eliminates complex flow guide structures while reducing flow resistance by shortening the effective length of the flow channel.

[0106] Through the above technical solution, this application solves the problem of bulky structure caused by the complex flow channel layout of traditional piezoelectric pumps. By coordinating multiple inlets on the outer periphery and a central outlet, a compact structure is achieved while ensuring flow balance. The natural convergence characteristics of fluid in the radial flow channel effectively improve flow efficiency and reduce energy loss, providing a feasible spatial layout scheme for the miniaturization design of piezoelectric pumps.

[0107] The above description is merely an embodiment of this application and is not intended to limit the scope of protection of this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of protection of this application.

Claims

1. A piezoelectric pump, characterized in that, include: The housing (1), the metal substrate (2), and the piezoelectric ceramic actuator (3) are provided with a fluid inlet (11) and a fluid outlet (12). The fluid inlet (11) is provided with a first reverse resistance structure (4), and the fluid outlet (12) is provided with a second reverse resistance structure (5).

2. The piezoelectric pump according to claim 1, characterized in that, The first reverse resistance structure (4) includes: a first resistance body (41) disposed at the fluid inlet (11), the first resistance body (41) having a first concave surface (411) on the mounting surface facing the housing (1), and a first fluid channel (412) disposed at the center of the first resistance body (41), the first fluid channel (412) communicating with the center of the first concave surface (411); The fluid inlet (11) is provided with a first protrusion (111) that is adapted to the first concave surface (411). The gap between the first concave surface (411) and the first protrusion (111) forms a second valve body channel (413), which is connected to the fluid inlet (11).

3. The piezoelectric pump according to claim 2, characterized in that, The second reverse resistance structure (5) includes a second resistance body (51), the second resistance body (51) has a second concave surface (511) on the mounting surface facing the housing (1), and a third valve body channel (512) is provided at the center of the second resistance body (51), the third valve body channel (512) is connected to the center of the second concave surface (511); The fluid outlet (12) area is provided with a second protrusion (121) adapted to the second concave surface (511), and the gap between the second concave surface (511) and the second protrusion (121) forms a fourth valve body channel (513), which is connected to the fluid outlet (12).

4. The piezoelectric pump according to claim 1, characterized in that, The fluid inlet (11) is provided with multiple in a ring array. The first reverse resistance structure (4) includes multiple spiral channels (41a) arranged in the same spiral direction and connected to the fluid inlet (11). The end of the spiral channel (41a) is connected to the fluid outlet (12). The second reverse resistance structure (5) includes a flared structure (51a) provided at the fluid outlet (12).

5. The piezoelectric pump according to claim 4, characterized in that, The fluid inlet (11) is set at an angle to the flow direction of the spiral channel (41a). A first cavity (16) communicating with the spiral channel (41a) is provided at the fluid outlet (12). A spherical protrusion (202) is provided on the side of the metal substrate (2) facing the fluid outlet (12) corresponding to the first cavity (16). A pit structure (107) is provided at the fluid outlet (12) of the housing (1) corresponding to the position of the spherical protrusion (202).

6. The piezoelectric pump according to claim 1, characterized in that, The first reverse resistance structure (4) includes a first Tesla valve structure (41b) disposed on the side of the fluid inlet (11), and the second reverse resistance structure (5) includes a second Tesla valve structure (51b) disposed on the side of the fluid outlet (12). A first fluid cavity (16) is disposed between the first Tesla valve structure (41b) and the second Tesla valve structure (51b).

7. The piezoelectric pump according to claim 6, characterized in that, The first Tesla valve structure (41b) and the second Tesla valve structure (51b) are formed on the base plate (10) of the housing (1), and a second fluid cavity (17) is formed between the upper surface of the base plate (10) and the metal substrate (2).

8. The piezoelectric pump according to claim 6, characterized in that, The fluid inlet (11) is provided in multiple ways, and a plurality of first Tesla valve structures (41b) are provided corresponding to the plurality of fluid inlets (11).

9. The piezoelectric pump according to claim 1, characterized in that, The first reverse resistance structure (4) includes a first Tesla valve structure (41c) disposed on the side of the fluid inlet (11), and the second reverse resistance structure (4) is a flared structure (51c) disposed on the fluid outlet (12).

10. The piezoelectric pump according to claim 9, characterized in that, The fluid inlet (11) includes multiple inlets, which are evenly distributed on the outer periphery of the housing (1), and the fluid outlet (12) is located at the center of the housing (1).

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