Diaphragm pump with new sealing structure

Abstract

The application discloses a diaphragm pump with a novel sealing structure, comprising a cylinder body, a diaphragm assembly and a pump body; the diaphragm assembly is threadedly connected with the pump body, and the cylinder body is detachably connected with the pump body; the diaphragm assembly comprises a metal ring and a diaphragm; the outer ring of the metal ring is provided with threads, and the diaphragm is injection molded in the inner ring of the metal ring through a rubber coating process. The application optimizes the sealing design of three key parts, i.e., the internal connection of the diaphragm assembly, the connection of the diaphragm assembly with the pump body and the connection of the cylinder body with the pump body, constructs a complete sealing system of'multi-layer protection and precise sealing', comprehensively improves the sealing performance, operation reliability and working condition adaptation capability of the diaphragm pump, reduces the maintenance cost and guarantees the production safety.

Description

Technical Field

[0001] This invention relates to the field of diaphragm pump technology, and in particular to a diaphragm pump with a novel sealing structure. Background Technology

[0002] Diaphragm pumps, which rely on the reciprocating motion of a diaphragm to change the volume of the pump chamber to transport fluids, are widely used in industrial production. However, traditional diaphragm pumps have certain shortcomings in sealing performance. During long-term use, due to inadequate design of the sealing structure between the diaphragm and the pump body / cylinder, fluid leakage is prone to occur. This not only wastes the transported medium but may also pollute the surrounding environment. More seriously, when transporting corrosive or toxic media, leakage poses a threat to the personal safety of operators and also affects the overall working efficiency and service life of the diaphragm pump. In existing technologies, the diaphragm is mostly compressed by the cylinder, which is prone to failure after prolonged use. Summary of the Invention

[0003] According to an embodiment of the present invention, a diaphragm pump with a novel sealing structure is provided, comprising a cylinder, a diaphragm assembly, and a pump body; the diaphragm assembly is threadedly connected to the pump body, and the cylinder is detachably connected to the pump body.

[0004] Furthermore, the diaphragm assembly includes a metal ring and a diaphragm; the outer ring of the metal ring is threaded, and the diaphragm is injection-molded onto the inner ring of the metal ring using an overmolding process. This overmolding process creates an integrated structure between the diaphragm and the metal ring, completely eliminating gaps between them compared to traditional compression seals. The metal ring provides rigid support for the diaphragm, resisting the impact of fluid pressure, reducing deformation and aging caused by uneven stress, extending the diaphragm's service life, and ensuring the stability of the diaphragm's reciprocating motion, thus guaranteeing the effectiveness of pump chamber volume changes.

[0005] Furthermore, the diaphragm is made of one of the following materials: polytetrafluoroethylene, ethylene propylene diene monomer (EPDM) rubber, fluororubber, hydrogenated nitrile rubber, chloroprene rubber, or silicone, which is existing technology.

[0006] Furthermore, a pair of first positioning holes are provided on the metal ring to facilitate tightening of the diaphragm assembly. The positioning holes provide a force application point for special installation tools (such as wrenches with protruding pins or calipers). Operators can apply tightening force precisely through the positioning holes to ensure that the threaded connection between the diaphragm assembly and the pump body reaches the preset torque, avoiding thread loosening caused by uneven or insufficient manual tightening force, ensuring connection sealing and stability, while simplifying the installation process and improving assembly efficiency.

[0007] Furthermore, the inner ring of the metal ring is provided with a first annular groove, which makes the connection between the injection-molded diaphragm and the metal ring tighter. The first annular groove forms a "mechanical interlocking" structure. During injection molding, the molten PTFE material will fully fill the groove. After cooling and molding, it will form a firm interlocking connection with the metal ring, which will greatly increase the contact area and connection strength between the two. This effectively prevents the diaphragm from relative displacement or peeling off from the metal ring during high-frequency reciprocating motion, strengthens the sealing performance from the inside of the diaphragm assembly, and avoids the leakage of the medium from the connection gap between the diaphragm and the metal ring.

[0008] Furthermore, the pump body is provided with a first threaded hole, in which the diaphragm assembly is installed, and the cylinder body is threadedly connected to the pump body through the first threaded hole. The first threaded hole provides a common connection reference for the diaphragm assembly and the cylinder body, realizing a "one hole for two purposes" design: on the one hand, it simplifies the pump body structure, reduces the number of holes to be machined, and lowers the processing difficulty and cost; on the other hand, it ensures the coaxiality of the diaphragm assembly, cylinder body, and pump body, avoids sealing deviations caused by misalignment of multiple holes, and makes the assembly process simpler, facilitating subsequent maintenance and disassembly.

[0009] Furthermore, the pump body is also provided with a first sealing groove, and a first sealing ring is installed in the first sealing groove; the first sealing groove is coaxial with the first threaded hole and is located at the lower end of the first thread. The first sealing ring is preferably made of fluororubber. When the diaphragm assembly is tightened in the first threaded hole, the lower end face of the diaphragm assembly will fit tightly with the first sealing ring, forming a double sealing structure of "thread seal + sealing ring seal", which completely blocks the path of medium leakage from the thread meshing gap, and improves the sealing level of the diaphragm assembly and the pump body to the industrial-grade IP67 leak-proof standard.

[0010] Furthermore, a first threaded portion is provided at the lower end of the cylinder body, which is threadedly connected to a first threaded hole. The thread parameters (pitch, thread profile, and accuracy grade) of the first threaded portion are perfectly matched with those of the first threaded hole, ensuring high-precision thread engagement between the two. The thread engagement surfaces fit tightly together, forming the first sealing barrier between the cylinder body and the pump body, effectively preventing media leakage from the connection surface between the cylinder body and the pump body, while providing stable support and positioning for the cylinder body.

[0011] Furthermore, a second sealing groove is provided at the bottom of the cylinder body, located on the outer ring of the threaded portion, and a second sealing ring is installed inside the second sealing groove. The second sealing groove is coaxial with the cylinder body and located below the first threaded portion; the second sealing ring is preferably made of nitrile rubber or fluororubber (selected according to the conveying medium; nitrile rubber is oil-resistant, and fluororubber is resistant to strong corrosion). When the cylinder body and the pump body are fixed by a threaded connection, the second sealing ring is tightly squeezed by the bottom of the cylinder body and the surface of the pump body, forming a second sealing line between the cylinder body and the pump body. This works in conjunction with the threaded seal to completely eliminate the potential leakage at the connection between the cylinder body and the pump body.

[0012] Furthermore, the cylinder body is provided with several second positioning holes, and the pump body is provided with second threaded holes corresponding to these second positioning holes one by one. The cylinder body and pump body are fixedly connected by screws inserted into the first positioning holes and the corresponding second threaded holes. This secondary fixing design effectively prevents the cylinder body from rotating or loosening during diaphragm pump operation due to fluid pressure fluctuations, diaphragm reciprocating impacts, or other factors. This ensures stable support pressure of the cylinder body on the diaphragm, avoids pressure attenuation of the sealing surface due to cylinder body displacement, and further guarantees the stability of the overall sealing structure.

[0013] Compared with the prior art, the present invention has the following beneficial effects: 1. Significantly improved sealing performance: This invention utilizes a multi-layer sealing system consisting of "internal interlocking seal of the diaphragm assembly + double seal between the diaphragm assembly and the pump body + double seal between the cylinder and the pump body + secondary fixing with screws" to construct protection from all critical parts where leakage may occur. The sealing level reaches the industrial-grade leak-proof standard, enabling the safe transport of highly hazardous media such as toxic, corrosive, flammable, and explosive substances, thus eliminating safety hazards.

[0014] 2. Strong adaptability to working conditions and wide range of applications: Diaphragm pumps can withstand a temperature range of -200℃ to 260℃ and resist corrosion from most strong acids, strong alkalis, strong oxidants and organic media.

[0015] 3. Stable and reliable operation with a long service life: The rigid support of the diaphragm by the metal ring and the interlocking structure of the annular groove reduce diaphragm deformation and wear; the double sealing design avoids continuous corrosion of the seals by the medium; the secondary fixing with screws ensures the stability of the cylinder position. All structural optimizations extend the replacement cycle of vulnerable parts such as the diaphragm and sealing rings, reducing maintenance costs and downtime losses. 4. Simple and reasonable structure, convenient assembly and maintenance: The "one hole for two uses" design simplifies the pump body structure and processing flow; the first positioning hole on the metal ring facilitates the precise installation of the diaphragm assembly; the detachable connection between the cylinder and the pump body and the clear assembly torque requirements enable operators to quickly complete disassembly and maintenance without complicated special equipment, improving production and maintenance efficiency and reducing labor costs.

[0016] It should be understood that both the foregoing general description and the following detailed description are exemplary and intended to provide further illustration of the claimed technology. Attached Figure Description

[0017] Figure 1 This is an exploded view of a portion of the structure according to an embodiment of the present invention; Figure 2 This is a schematic diagram of the structure according to an embodiment of the present invention; Figure 3 for Figure 2 Top view; Figure 4 for Figure 4 Sectional view along axis AA; Figure 5 for Figure 4 Enlarged view of point A; Figure 6 This is a schematic diagram of the cylinder block according to an embodiment of the present invention. Detailed Implementation

[0018] The preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings, further illustrating the present invention.

[0019] First, combine Figures 1-6 The diaphragm pump with a novel sealing structure according to embodiments of the present invention is widely used in industries with stringent requirements for fluid conveying sealing and safety, such as chemical, pharmaceutical, food processing, environmental protection, and petrochemical industries. It can stably convey various types of media, including water, oil, strong acid and alkali solutions, toxic media, and fluids containing particles.

[0020] like Figures 1-6 As shown, the diaphragm pump with a novel sealing structure according to an embodiment of the present invention includes a cylinder 1, a diaphragm assembly 2 and a pump body 3; the diaphragm assembly 2 is threadedly connected to the pump body 3, and the cylinder 1 and the pump body 3 are detachably connected. Furthermore, such as Figure 1 , 4 As shown in Figure 5, in this embodiment, the diaphragm assembly 2 includes a metal ring 21 and a diaphragm 22. The outer ring of the metal ring 21 is threaded, and the diaphragm 22 is injection molded onto the inner ring of the metal ring 21 using an overmolding process. The overmolding process makes the diaphragm 22 and the metal ring 21 form an integrated structure, which completely eliminates the gap between the two compared to the traditional compression seal. The metal ring 21 provides rigid support for the diaphragm 22, which can resist the impact of fluid pressure on the diaphragm 22, reduce the deformation and aging of the diaphragm 22 caused by uneven stress, extend the service life of the diaphragm 22, and at the same time ensure the stability of the reciprocating motion of the diaphragm 22, ensuring the effectiveness of the pump cavity volume change. Furthermore, in this embodiment, the diaphragm is made of one of the following materials: polytetrafluoroethylene, ethylene propylene diene monomer (EPDM) rubber, fluororubber, hydrogenated nitrile rubber, chloroprene rubber, or silicone.

[0021] Furthermore, such as Figure 1 As shown, in this embodiment, the metal ring 21 is provided with a pair of first positioning holes 211 to facilitate tightening of the diaphragm assembly 2. The first positioning holes 211 provide a force application point for special installation tools (such as wrenches with protrusions or calipers). Operators can accurately apply tightening force through the first positioning holes 211 to ensure that the threaded connection between the diaphragm assembly 2 and the pump body 3 reaches the preset torque, avoiding thread loosening caused by uneven or insufficient manual tightening force, ensuring connection sealing and stability, while simplifying the installation process and improving assembly efficiency. Furthermore, such as Figures 4-5 As shown, in this embodiment, the inner ring of the metal ring 21 is provided with a first annular groove 212, which makes the connection between the injection-molded diaphragm 22 and the metal ring 21 more tight. The first annular groove 212 forms a "mechanical interlocking" structure. During injection molding, the molten material will fully fill the groove. After cooling and molding, it will form a firm interlocking connection with the metal ring 21, which greatly increases the contact area and connection strength between the two. This effectively prevents the diaphragm 22 from relative displacement or peeling from the metal ring 21 during high-frequency reciprocating motion, strengthens the sealing performance from the inside of the diaphragm assembly 2, and avoids the leakage of the medium from the connection gap between the diaphragm 22 and the metal ring 21. Furthermore, such as Figure 1 , 4 As shown in Figure 5, in this embodiment, the pump body 3 is provided with a first threaded hole 31, the diaphragm assembly 2 is installed in the first threaded hole 31, and the cylinder body 1 is threadedly connected to the pump body 3 through the first threaded hole 31. The first threaded hole 31 provides a common connection reference for the diaphragm assembly 2 and the cylinder body 1, realizing a "one hole for two uses" design: on the one hand, it simplifies the structure of the pump body 3, reduces the number of holes to be machined, and reduces the processing difficulty and cost; on the other hand, it ensures the coaxiality of the diaphragm assembly 2, the cylinder body 1 and the pump body 3, avoids sealing deviation caused by misalignment of multiple holes, and makes the assembly process simpler and facilitates subsequent maintenance and disassembly. Furthermore, such as Figures 4-5 As shown, in this embodiment, the pump body 3 is also provided with a first sealing groove 32, and a first sealing ring 33 is installed in the first sealing groove 32; the first sealing groove 32 is coaxial with the first threaded hole 31 and is located at the lower end of the first thread. The first sealing ring 33 is preferably made of fluororubber. When the diaphragm assembly 2 is tightened in the first threaded hole 31, the lower end face of the diaphragm assembly 2 will fit tightly with the first sealing ring 33, forming a double sealing structure of "thread seal + sealing ring seal", which completely blocks the path of leakage of the medium from the thread meshing gap, and improves the sealing level of the diaphragm assembly 2 and the pump body 3 to the industrial-grade IP67 leak-proof standard. Furthermore, such as Figures 4-6 As shown, in this embodiment, a first threaded portion 11 is provided at the lower end of the cylinder body 1, and the first threaded portion 11 is threadedly connected to the first threaded hole 31. The thread parameters (pitch, thread profile, and precision grade) of the first threaded portion 11 are perfectly matched with the first threaded hole 31, ensuring that the two achieve high-precision thread engagement. The thread engagement surfaces are tightly fitted, forming the first sealing barrier between the cylinder body 1 and the pump body 3, effectively preventing the medium from leaking from the connection surface between the cylinder body 1 and the pump body 3, while providing stable support and positioning for the cylinder body 1. Furthermore, such as Figures 4-5As shown, in this embodiment, a second sealing groove 12 is provided at the bottom of the cylinder body 1, and a second sealing ring 13 is provided in the second sealing groove 12. The second sealing groove 12 is coaxial with the cylinder body 1 and is located below the first threaded portion 11; the second sealing ring 13 is preferably made of nitrile rubber or fluororubber (selected according to the conveying medium, nitrile rubber is oil-resistant, and fluororubber is resistant to strong corrosion). When the cylinder body 1 and the pump body 3 are fixed by threaded connection, the second sealing ring 13 is tightly squeezed by the bottom of the cylinder body 1 and the surface of the pump body 3, forming a second sealing line between the cylinder body 1 and the pump body 3. It works in conjunction with the threaded seal to completely eliminate the leakage risk at the connection between the cylinder body 1 and the pump body 3. Furthermore, such as Figure 1 As shown, in this embodiment, the cylinder body 1 is provided with a plurality of second positioning holes 14, and the pump body 3 is provided with second threaded holes 34 corresponding one-to-one with the plurality of second positioning holes 14. The cylinder body 1 and the pump body 3 are fixedly connected by screws inserted into the second positioning holes 14 and the corresponding second threaded holes 34. Preferably, there are 3-4 second positioning holes 14, which are evenly distributed along the circumference of the cylinder body 1 to ensure balanced force. The screws are stainless steel internal hexagon screws with thread sealant applied to the surface. The secondary fixing design can effectively prevent the cylinder body 1 from rotating or loosening during the operation of the diaphragm 22 pump due to factors such as fluid pressure fluctuations and reciprocating impacts of the diaphragm 22, ensuring the stability of the support pressure of the cylinder body 1 on the diaphragm 22, avoiding the pressure attenuation of the sealing surface caused by the displacement of the cylinder body 1, and further ensuring the stability of the overall sealing structure.

[0022] Sealing principle: 1. Internal sealing of diaphragm assembly 2: The first annular groove 212 of the inner ring of metal ring 21 makes the diaphragm 22 and metal ring 21 fit tightly together, preventing the medium from leaking from the connection gap between the two; the material of diaphragm 22 itself is resistant to medium corrosion, and always maintains good elasticity and sealing performance, ensuring the effectiveness of pump cavity volume change. 2. Diaphragm assembly 2 and pump body 3 sealing: Diaphragm assembly 2 and pump body 3 are connected by high-precision threads to form a preliminary seal. The first sealing ring 33 in the first sealing groove 32 of pump body 3 is squeezed by the lower end face of diaphragm assembly 2 to form a second seal. The double protection completely blocks the leakage of the medium from this part. 3. Cylinder body 1 and pump body 3 sealing: The first threaded part 11 of cylinder body 1 and the first threaded hole 31 of pump body 3 are precisely engaged to form a preliminary seal. The second sealing ring 13 in the second sealing groove 12 at the bottom of cylinder body 1 is squeezed to form a second seal. At the same time, the screws are fixed for a second time to ensure the stability of the position of cylinder body 1 and to avoid the seal failure due to the loosening of cylinder body 1. Above, refer to Figures 1-6A diaphragm pump with a novel sealing structure according to an embodiment of the present invention is described. By optimizing the sealing design of three key parts—the internal connection of the diaphragm assembly 2, the connection between the diaphragm assembly 2 and the pump body 3, and the connection between the cylinder 1 and the pump body 3—a dedicated sealing structure is added to construct a complete sealing system of "multi-layer protection and precise sealing," thereby comprehensively improving the sealing performance, operational reliability, and adaptability to operating conditions of the diaphragm pump, reducing maintenance costs, and ensuring production safety.

[0023] It should be noted that, in this specification, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising..." does not exclude the presence of additional identical elements in the process, method, article, or apparatus that includes that element.

[0024] Although the present invention has been described in detail through the preferred embodiments above, it should be understood that the above description should not be considered as a limitation of the present invention. Various modifications and substitutions to the present invention will be apparent to those skilled in the art after reading the above description. Therefore, the scope of protection of the present invention should be defined by the appended claims.

Claims

1. A diaphragm pump with a novel sealing structure, characterized in that, It includes: a cylinder, a diaphragm assembly, and a pump body; the diaphragm assembly is threadedly connected to the pump body, and the cylinder is detachably connected to the pump body.

2. The diaphragm pump with a novel sealing structure as described in claim 1, characterized in that, The diaphragm assembly includes a metal ring and a diaphragm; the outer ring of the metal ring is threaded, and the diaphragm is injection molded onto the inner ring of the metal ring using an overmolding process.

3. The diaphragm pump with a novel sealing structure as described in claim 2, characterized in that, The diaphragm is made of one of the following materials: polytetrafluoroethylene, ethylene propylene diene monomer (EPDM) rubber, fluororubber, hydrogenated nitrile rubber, chloroprene rubber, or silicone.

4. The diaphragm pump with a novel sealing structure as described in claim 2, characterized in that, The metal ring is provided with a pair of first positioning holes to facilitate tightening of the diaphragm assembly.

5. The diaphragm pump with a novel sealing structure as described in claim 4, characterized in that, The inner ring of the metal ring is provided with a first annular groove, which makes the diaphragm after injection molding more tightly connected to the metal ring.

6. The diaphragm pump with a novel sealing structure as described in claim 1, characterized in that, The pump body is provided with a first threaded hole, the diaphragm assembly is installed in the first threaded hole, and the cylinder is threadedly connected to the pump body through the first threaded hole.

7. The diaphragm pump with a novel sealing structure as described in claim 6, characterized in that, The pump body is also provided with a first sealing groove, and a first sealing ring is installed in the first sealing groove; the first sealing groove is coaxial with the first threaded hole and is located at the lower end of the first thread.

8. The diaphragm pump with a novel sealing structure as described in claim 6, characterized in that, The cylinder body is threadedly connected to the pump body through the first threaded hole.

9. The diaphragm pump with a novel sealing structure as described in claim 8, characterized in that, The lower end of the cylinder is provided with a first threaded portion, which is threadedly connected to the first threaded hole.

10. The diaphragm pump with a novel sealing structure as described in claim 1, characterized in that, The bottom of the cylinder is provided with a second sealing groove, and a second sealing ring is provided in the second sealing groove.

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