Metal film disc coupling and its processing method

Abstract

The application belongs to the technical field of couplings, and particularly relates to a metal membrane disc coupling and a processing method thereof. The metal membrane disc coupling comprises a flange disc, a coupling joint and a metal membrane disc, and the metal membrane disc is arranged between the flange disc and the coupling joint. In particular, the metal membrane disc comprises an upper closed membrane, a middle layer membrane and a lower closed membrane, at least one side surface of the middle layer membrane is provided with a plurality of microgrooves arranged along a predetermined path, the microgrooves are filled with liquid metal, the upper closed membrane and the lower closed membrane are respectively arranged on the upper and lower sides of the middle layer membrane, and are used for closing the microgrooves and forming a closed liquid metal microcavity structure. In the application, the liquid metal is filled in the microgrooves of the middle layer membrane, and the good fluidity and high thermal conductivity of the liquid metal can be used to actively migrate to a local high load area when stress is concentrated or temperature rises, so that stress relief and heat diffusion are realized, and the fatigue resistance and thermal stability of the membrane are improved, and the service life of the coupling is prolonged.

Description

Technical Field

[0001] This invention belongs to the field of coupling technology, specifically relating to a metal diaphragm disc coupling and its processing method. Background Technology

[0002] Metal diaphragm couplings are flexible couplings widely used in high-precision, high-speed, and high-response applications. These couplings mainly consist of two connecting parts (such as a coupling joint and a flange) and a metal diaphragm disc sandwiched between them. The diaphragm disc is typically made of high-strength metal sheets, such as stainless steel or titanium alloy, and is fastened to the connecting parts by multiple bolts. During operation, the diaphragm disc utilizes its elastic deformation capacity to transmit torque while compensating for minute axial, angular, and radial displacements between shafts. It possesses advantages such as simple structure, no lubrication required, zero backlash, and high rigidity, and is therefore widely used in aerospace, wind power equipment, precision CNC machine tools, high-speed pumps, and compressors.

[0003] However, in actual operation, diaphragm couplings often experience problems such as diaphragm fatigue cracking and deformation failure due to factors such as prolonged high-speed rotation, frequent start-stop cycles, and drastic temperature changes. The most common failure mode is fatigue cracking at the root region of the diaphragm where it connects to the coupling or flange. This location is prone to stress concentration due to the combined effects of bolt clamping force, bending stress, and torsional stress, forming a crack initiation point. Furthermore, the diaphragm is subjected to high-frequency stress cycles for extended periods, easily leading to localized temperature rises. If heat dissipation is insufficient, this will further induce thermal fatigue and accelerate damage development.

[0004] To address the aforementioned issues, some improvement solutions have been proposed, attempting to adjust the diaphragm material selection, shape optimization, and connection method improvements. For example, multi-layer stacked structures, corrugated reinforcement zones, and improved connection hole processing techniques have been adopted. However, these solutions still fail to resolve the critical contradiction that "local stress and heat at the diaphragm root cannot be actively relieved," thus limiting the service life and reliability of diaphragm couplings under extreme operating conditions. Summary of the Invention

[0005] To address the above problems, the present invention provides a metal diaphragm disc coupling, comprising a flange, a coupling, and a metal diaphragm disc disposed between the flange and the coupling. Specifically, the metal diaphragm disc comprises an upper sealing diaphragm, a middle sealing diaphragm, and a lower sealing diaphragm, wherein the upper sealing diaphragm, the middle sealing diaphragm, and the lower sealing diaphragm are all metal. At least one side surface of the middle sealing diaphragm is provided with a plurality of microgrooves arranged along a predetermined path, the microgrooves being filled with liquid metal. The upper sealing diaphragm and the lower sealing diaphragm are respectively disposed on the upper and lower sides of the middle sealing diaphragm to seal the microgrooves, forming a closed liquid metal microcavity structure.

[0006] This invention constructs a sandwich diaphragm system with "stress-thermal adaptive adjustment capability" by introducing liquid metal microchannels arranged along a predetermined path into the middle layer of a metal diaphragm disc, and forming a closed liquid metal microcavity structure using upper and lower closed diaphragms. When stress concentration or localized temperature rise occurs at the root of the diaphragm during operation, the liquid metal in the microchannels flows and redistributes at a microscale, actively flowing towards stress hotspots or high-temperature areas, thereby unloading local stress and diffusing and buffering heat energy. This reduces the risk of crack initiation, delays fatigue failure, and improves the fatigue resistance and service life of the diaphragm disc. This mechanism breaks the traditional rigid structure's passive load-bearing mode, enabling the diaphragm to have a flexible adjustment capability similar to an "intelligent buffer layer" in the critical root region.

[0007] Furthermore, the thickness of the upper and lower sealing membranes is 0.05-0.12 mm, while the thickness of the middle membrane is 0.1-0.3 mm. In other words, the middle membrane is thicker, while the upper and lower sealing membranes are thinner. The middle membrane bears the main mechanical loads and elastic deformations; the upper and lower sealing membranes are mainly used to seal the microgroove and protect the internal liquid metal interlayer. This thickness distribution gives the middle membrane good structural strength and fatigue resistance, ensuring it maintains overall rigidity and elastic response under high-frequency stress. Simultaneously, the upper and lower sealing membranes possess better flexibility and conformability, facilitating flexible flow and stress adaptive adjustment of the liquid metal within the microgroove, and enhancing the membrane's buffering capacity against localized stress and thermal fields.

[0008] Furthermore, the microgrooves and the liquid metal filling are only distributed in the root region of the intermediate diaphragm. This serves two purposes: firstly, the root region is a high-risk area for stress concentration and fatigue cracking during operation; concentrating the liquid metal microgrooves here strengthens the stress buffering and heat dissipation capabilities of this region, improving fatigue resistance; secondly, the non-root regions maintain a continuous solid structure, avoiding the overall stiffness reduction or structural complexity that would result from fully covering the microgrooves, thus balancing the mechanical stability of the diaphragm with manufacturing simplification. In addition, the localized placement of microgrooves reduces the amount of liquid metal used and processing costs, facilitating efficient, reliable, and economical structural optimization.

[0009] Furthermore, the microgrooves are radially strip-shaped structures extending from the center of the intermediate diaphragm towards the outer diameter. This arrangement of microgrooves better conforms to the stress distribution path of the diaphragm disk during torque transmission and bending deformation, allowing the liquid metal to flow flexibly along the principal stress direction, achieving more efficient stress response and hotspot mitigation. The radial strip structure facilitates the construction of multiple independent or interconnected liquid metal channels. When local overload or temperature rise occurs in the root region, the liquid metal can migrate and diffuse towards the outer diameter, thereby reducing local stress peaks. In addition, the strip-shaped structure is easy to process and arrange regularly, facilitating the achievement of microgroove consistency and sealing reliability during manufacturing, representing an optimized balance between structural performance and engineering feasibility.

[0010] Furthermore, the microgrooves have a depth of 10-100 micrometers and a width of 50-300 micrometers, with rectangular or circular cross-sections. This minimizes interference with the overall thickness and mechanical properties of the diaphragm while ensuring the filling and flow of the liquid metal. The moderate microgroove size allows the liquid metal to have good capillary drive and stress response capabilities within the groove, enabling it to rapidly flow to high-stress areas during thermal expansion and contraction or localized stress changes, forming a dynamic buffer. The rectangular and circular cross-sections respectively balance ease of fabrication and uniform stress distribution; the circular shape reduces stress concentration and improves fatigue life, while the rectangular shape facilitates groove volume control and process consistency.

[0011] Furthermore, the liquid metal is either a gallium-indium-tin alloy or a gallium-indium alloy. Both of these liquid alloys are liquid at room temperature and possess excellent thermal conductivity, low vapor pressure, and good metal wettability, making them particularly suitable for stress buffering and heat diffusion functions in microscale structures. Their high thermal conductivity helps to quickly dissipate heat when the diaphragm experiences localized temperature rises, preventing localized heat accumulation that could lead to thermal fatigue. Their good fluidity and compressibility allow them to actively flow towards stress concentration areas when the diaphragm is under stress, achieving micro-stress redistribution and improving fatigue life. In addition, gallium-indium alloys possess good stability, chemical inertness, and affinity for metal tank walls; they are not easily volatilized or oxidized, and can maintain stable performance over long periods within closed microcavities, thus ensuring the reliability and safety of the diaphragm coupling under high-intensity, long-life operating conditions.

[0012] Furthermore, at the root region of the intermediate diaphragm, multiple branch channels communicating with the microgrooves are provided on both sides of the microgrooves, with the width of the branch channels being smaller than the width of the microgrooves. This composite channel structure of "main channel + fine branches" can further enhance the response flexibility and flow path complexity of liquid metal in local stress fields. When the diaphragm is subjected to forces in different directions or experiences multi-point stress concentration, the liquid metal can be more evenly dispersed and flowed through the branch channels, rapidly penetrating to the micro-stress hotspot areas, thereby achieving more refined stress relief and heat diffusion. At the same time, the narrow and wide design of the branch channels can limit the flow range of the liquid metal, avoiding large-scale migration that could adversely affect the overall stiffness of the diaphragm. This structure also has a similar effect to a "capillary network," providing multi-channel compensation paths at the microscopic level, enhancing the diaphragm's fatigue resistance and high-load capacity, and improving the overall operational stability and reliability.

[0013] On the other hand, the present invention provides a method for processing a metal diaphragm disc coupling, comprising the following steps:

[0014] Step 1: Provide flanges and couplings;

[0015] Step 2: Provide the upper sealing membrane, the middle sealing membrane, and the lower sealing membrane;

[0016] Step 3: Process multiple microgrooves in the radial direction on the intermediate layer film;

[0017] Step 4: Inject liquid metal into the micro-groove to form a liquid metal channel;

[0018] Step 5: Attach the upper and lower sealing films to the upper and lower sides of the middle film and seal the microgrooves to form a metal film disk.

[0019] Step 6: Prepare connection holes in the edge region of the metal film disk;

[0020] Step 7: Assemble the metal diaphragm between the flange and the coupling, and fix it with bolts.

[0021] This invention employs a processing method of "first preparing an intermediate layer membrane, then bonding the upper and lower sealing membranes," offering the advantage of process controllability. By precisely machining microgrooves on the intermediate layer membrane and injecting liquid metal, the dimensional consistency and filling integrity of the liquid metal channels can be ensured, avoiding the risk of groove misalignment or liquid metal leakage caused by simultaneous processing of multiple layers. Subsequently, the upper and lower thin film sheets are bonded and encapsulated, achieving stable coverage and high-quality sealing of the microgroove structure, thus improving the overall structural strength and durability of the membrane disk. Simultaneously, this step-by-step manufacturing process facilitates independent inspection of the microstructure quality of the intermediate functional layer, promoting standardization and automation of the production process, reducing rework rates, and improving the consistency and reliability of finished products.

[0022] Furthermore, in step 3, CNC technology or laser etching technology is applied to fabricate microgrooves. CNC (Computer Numerical Control) technology is a high-precision machining technology based on automatic tool movement control by a numerical control system, suitable for fine cutting, milling, or engraving of materials such as metals and plastics. In this invention, step 3 uses CNC technology or laser etching technology to process the microgrooves of the intermediate layer membrane, enabling high-precision control of the microgroove shape, size, and arrangement path, ensuring uniformity in groove depth, width, and cross-sectional contour, thereby improving the consistency and structural reliability of the liquid metal channel. CNC technology is suitable for stable batch processing of large-size, multi-groove arrays, offering neat cutting and strong material adaptability; laser etching, on the other hand, has advantages such as non-contact processing, minimal local heat impact, and precise controllable microstructures, making it particularly suitable for manufacturing complex micron-level groove structures. The combination or selective use of these two technologies allows for flexible selection of processing schemes based on membrane material and design requirements, improving the quality, efficiency, and yield of microgroove processing in this invention.

[0023] Furthermore, in step 4, liquid metal is injected into the microchannels via dripping or capillary diversion. This injection method offers advantages such as ease of operation, precise control, and adaptability to microscale structures. The dripping method allows for quantitative filling of each microchannel, suitable for precise point injection; while capillary diversion utilizes the surface tension of the liquid metal and the capillary effect of the microchannel structure to automatically and rapidly spread and fill the channels without external pressure, making it suitable for narrow and tortuous microchannel structures. Compared to traditional injection or pressure injection methods, these two methods cause less disturbance to the diaphragm structure and have a lower thermal impact, avoiding problems such as liquid metal overflow, air bubble entrainment, or tank damage. This ensures a uniform and stable distribution of the liquid metal within the tank, providing a solid foundation for subsequent diaphragm bonding and overall coupling performance.

[0024] Furthermore, in step 5, the intermediate diaphragm layer is sealed using either thermocompression welding or micro-diffusion welding. Thermocompression welding utilizes temperature and pressure to form a stable bonding interface on the metal diaphragm surface, suitable for large-area rapid encapsulation. Micro-diffusion welding achieves interatomic diffusion bonding at lower temperatures and without melting, preserving the microgroove structure morphology and preventing liquid metal volatilization or thermal deformation, making it suitable for high-reliability connections with intricate structures. Both welding methods achieve high-strength bonding and high sealing between diaphragm layers, preventing liquid metal leakage, oxidation, or migration, while maintaining the overall flatness and flexibility of the diaphragm disc, thus ensuring the structural stability and performance consistency of the coupling during long-term operation.

[0025] Furthermore, in step 6, at least one edge of the connecting hole is chamfered, with the chamfer being a rounded transition structure. Since the connecting hole is a critical area where bolt tightening force and working stress intersect, it is often the starting area for crack initiation and fatigue failure. Using a rounded chamfer makes the stress distribution at the hole edge smoother, avoiding sudden local stress changes caused by sharp edges. At the same time, the chamfer also improves the mechanical tolerance of the diaphragm during assembly, reduces damage caused by edge burrs or assembly misalignment, enhances the strength and service life of the hole structure, and provides important protection for the stable operation of the entire coupling system.

[0026] The beneficial effects of this invention are:

[0027] (1) The present invention introduces liquid metal to fill the microgroove of the intermediate diaphragm. With its good fluidity and high thermal conductivity, it can actively migrate to the local high load area when stress is concentrated or temperature rises, so as to realize stress relief and heat diffusion, thereby improving the fatigue resistance and thermal stability of the diaphragm and extending the service life of the coupling.

[0028] (2) The present invention limits the liquid metal micro-groove structure to the root region of the membrane disk, and achieves local reinforcement of the high-risk area of ​​the membrane disk that is prone to fatigue cracking. Without affecting the overall stiffness and manufacturing cost, it improves the root crack resistance and operational reliability, and achieves a balance between structural function and economy.

[0029] (3) The micro-groove of the present invention has fine branch grooves on both sides, which helps the liquid metal to diffuse more flexibly under stress in different directions, forming a stress buffer path similar to a capillary network, further refining the adjustment area, uniformly distributing the load, strengthening the local "intelligent response" capability of the membrane disk, and improving the structural toughness and fatigue resistance.

[0030] (4) The present invention adopts a three-step structured manufacturing process of “pre-tank processing, liquid metal filling and hot-press sealing”, combined with CNC or laser processing technology, drip / capillary filling and hot-press / diffusion welding packaging process to achieve high precision, high sealing and high consistency of sandwich membrane preparation, ensuring product reliability and mass production.

[0031] (5) The connection hole edge of the present invention is provided with a rounded chamfer, which reduces the edge stress concentration caused by the bolt preload, avoids local tearing or crack initiation of the diaphragm, improves the fatigue strength and stability of the diaphragm connection part, enhances the adaptability during the assembly process, and reduces the risk of structural damage caused by stress change.

[0032] Based on the above beneficial effects, this invention has good application prospects in the field of coupling technology. Attached Figure Description

[0033] Figure 1 This is a schematic diagram of a metal film disk.

[0034] Figure 2 This is a schematic diagram of the root region of the intermediate layer membrane.

[0035] Figure 3 Schematic diagram of microgrooves and branch grooves.

[0036] In the diagram: 1. Upper sealing membrane; 2. Middle membrane; 3. Lower sealing membrane; 4. Connecting hole; 5. Microgroove; 6. Branch groove; 21. Root region. Detailed Implementation

[0037] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided with reference to the accompanying drawings and embodiments.

[0038] Example 1

[0039] This embodiment provides a metal diaphragm coupling, including a coupling, a flange, and a metal diaphragm disc disposed between the two. The coupling is used to connect to a driving shaft, the flange is used to connect to a driven shaft, and the metal diaphragm disc is used to transmit torque between the two shafts while compensating for axial, radial, or angular installation misalignments.

[0040] Generally, one end of the coupling has a high-precision cylindrical shaft hole that matches the outer diameter of the drive shaft. A keyway can be optionally provided on the inner wall of the shaft hole to mate with the key teeth on the drive shaft, enhancing torsional resistance. A radial slit structure and multiple circumferentially distributed clamping screw holes are provided on the outer circumference of the coupling's shaft hole. After installing the screws, radial tightening can be achieved, clamping the coupling firmly to the surface of the drive shaft. This connection method ensures good coaxiality and torque transmission between the coupling and the drive shaft, while also featuring convenient assembly and disassembly, high reliability, and suitability for long-term operation under dynamic loads. Generally, the flange center has a positioning hole that matches the end of the driven shaft. The inner side of the positioning hole can achieve precise alignment and radial support with the driven shaft shoulder through an transition fit or interference fit. Multiple bolt through holes are evenly distributed around the flange circumference for mating with threaded holes on the flange face of the driven shaft end. High-strength bolts reliably fasten the flange to the end face of the driven shaft. This connection structure can effectively bear axial thrust and torque, maintain the coaxiality and stability of the flange and driven shaft, and is suitable for high-precision and high-load power transmission scenarios.

[0041] like Figure 1As shown, the metal membrane disk adopts a three-layer composite structure, consisting of an upper sealing membrane 1, a middle membrane 2, and a lower sealing membrane 3 from top to bottom. The upper sealing membrane 1 is a 0.08 mm thick TC4 titanium alloy foil, which possesses excellent toughness, corrosion resistance, and fatigue resistance, effectively sealing the internal microstructure and protecting it from external influences in complex environments. The middle membrane 2 is 0.2 mm thick and made of SUS316 austenitic stainless steel, serving as the main load-bearing layer of the metal membrane disk. One side surface of the middle membrane 2 (facing the upper sealing membrane 1) has multiple radially distributed microgrooves extending from the center of the middle membrane 2 outwards, forming a radially symmetrical groove array structure. These microgrooves are 50 micrometers deep and 200 micrometers wide, with an arc-shaped cross-section, and are filled with gallium indium tin alloy liquid metal, forming a closed liquid metal microcavity network to achieve stress response mitigation and thermal field regulation. The structure of the lower sealing membrane 3 is symmetrical and consistent with that of the upper sealing membrane 1. It is also a TC4 titanium alloy foil with a thickness of 0.08 mm. Its function is the same as that of the upper layer, which is used to seal the other side of the middle membrane 2 to ensure the sealing and stability of the liquid metal in the micro-groove.

[0042] The entire three-layer structure is integrated and fixed through multi-point edge connection. The outer edge of the metal diaphragm has multiple evenly distributed connection holes for bolt connection and fastening with couplings and flanges, realizing the overall assembly and transmission functions of the structure.

[0043] The metal diaphragm disc coupling in this embodiment utilizes multi-layer material synergy and microstructure functional embedding to construct a high-performance coupling structure with local stress adaptive adjustment capability and strong crack and corrosion resistance, meeting the long-term stable operation requirements under complex working conditions. It is suitable for power transmission systems in aerospace, ship propulsion systems and marine equipment.

[0044] Example 2

[0045] Based on Example 1, both the upper sealing diaphragm 1 and the lower sealing diaphragm 3 of the metal diaphragm disk are made of copper foil or nickel-plated copper foil with a thickness of 0.06 mm, while the middle layer diaphragm 2 remains a 0.2 mm thick SUS316 stainless steel sheet. Compared to the titanium foil structure used in Example 1, copper foil has superior thermal conductivity and processing ductility, making it suitable for applications with high requirements for thermal management performance and electromagnetic compatibility, such as high-speed motors, precision servo systems, and power electronic equipment. Nickel plating further enhances the oxidation and corrosion resistance of the copper foil surface, improving overall service life. This structure is more suitable for medium-low temperature, dry, or electromagnetically sensitive working environments, achieving good heat dissipation and electrical shielding effects while maintaining the flexibility and fatigue strength of the diaphragm disk.

[0046] Example 3

[0047] Based on Example 1, the upper sealing diaphragm 1, lower sealing diaphragm 3, and middle diaphragm 2 of the metal diaphragm disk are all made of martensitic stainless steel. The upper sealing diaphragm 1 and lower sealing diaphragm 3 have a thickness of 0.06 mm, and the middle diaphragm has a thickness of 0.25 mm. Compared to the titanium-stainless steel composite structure in Example 1, this design achieves a full martensitic steel design, resulting in higher strength, hardness, and impact resistance. It is suitable for mechanical systems subjected to high torque transmission, high-frequency impact loads, or low-temperature impact environments, such as mining equipment, hydraulic system drive couplings, and low-temperature power machinery. Furthermore, a unified material system helps eliminate internal stress caused by differences in thermal expansion coefficients, while simplifying the welding process and improving the overall reliability and manufacturing consistency of the structure.

[0048] Example 4

[0049] Based on Examples 1-3, such as Figure 2 As shown, the microgrooves on the intermediate diaphragm 2 and the liquid metal they fill are only distributed in the root region 21 of the diaphragm, that is, near the connecting hole 4, adjacent to the metal diaphragm disk and the flange, and the annular region at the edge where the coupling is bolted. The root region 21 is generally located within 20% of the outer edge of the metal diaphragm disk radius. In other words, in this embodiment, the microgrooves are set in an annular band formed between 85% and 100% of the outer diameter of the intermediate diaphragm 2.

[0050] Within this region, multiple microgrooves are uniformly arranged radially, forming a radial strip structure. Each microgroove is approximately 200 micrometers wide and 50 micrometers deep, with a circular arc cross-section and filled with liquid gallium indium tin alloy. The length of the microgroove is limited to the root annulus and does not extend into the central flexible region of the diaphragm to maintain the elastic deformation properties of the central area.

[0051] The root region 21 is a stress concentration area and a high-risk area for cracking during operation. By setting a closed liquid metal microgroove structure only in this region, the stress concentration in the root region 21 can be alleviated and crack initiation can be delayed without significantly increasing the rigidity of the central area of ​​the metal diaphragm disk, thus maintaining the required flexible compensation capability of the coupling. At the same time, this localized functional structure is also beneficial to manufacturing, avoiding the complex process and liquid metal filling difficulties caused by slotting the entire surface of the intermediate layer diaphragm 2, reducing processing costs and packaging difficulty.

[0052] This embodiment is suitable for applications that require high fatigue life and have strict control over cost and complexity, such as medium- and high-speed automated mechanical systems and electric drive transmission devices, which improve economic applicability while ensuring high reliability.

[0053] Example 5

[0054] Based on embodiments 1-3, multiple branch grooves 6 are provided in the root region 21 of the intermediate layer diaphragm 2 (i.e., the outer annular region near the connecting bolt hole). Figure 3 As shown in the figure, branch groove 6 and micro groove 5 are connected, and these microstructures together constitute a self-adjustable liquid metal distribution network.

[0055] Microgrooves 5 are arranged radially in a strip-like pattern, extending from the outer edge of the intermediate membrane 2 towards the center. On both sides of each microgroove 5, multiple small branch grooves 6 are obliquely distributed at a certain angle. These branch grooves 6 are connected to the microgrooves 5, forming a fluid-connected structure. The width of the branch grooves 6 is 30-80 micrometers, smaller than the 200-micrometer width of the microgrooves 5, while the depth is similar to that of the microgrooves 5, around 50 micrometers. This structure is similar to a "liquid metal diversion capillary network," capable of driving the liquid metal to diffuse towards the stress hotspot when local stress concentration or temperature rise occurs in the root region 21 of the intermediate membrane 2, thereby achieving local unloading and heat diffusion.

[0056] In this embodiment, branch grooves 6 are provided only in the root region 21, while no branch groove structure 6 is provided in the central flexible region of the intermediate diaphragm 2, maintaining the structural continuity and elastic flexibility of the central region. This "functional zoning design" enables the diaphragm to have stress relief and micro-strain homogenization capabilities in critical high-load areas, while maintaining flexibility in the central part to meet the coupling's compensation requirements for axial, radial, and angular displacements.

[0057] This embodiment is particularly suitable for transmission scenarios that are subjected to cyclic loads, dynamic imbalances, and significant temperature rises, such as high-speed CNC spindles, robot joint motors, or auxiliary transmission systems for aero-gas turbines. It helps to significantly improve the fatigue life of the diaphragm root and the reliability of system operation.

[0058] Example 6

[0059] This embodiment provides a method for processing a metal diaphragm disc coupling, including the following steps:

[0060] Step 1: Provide flanges and couplings. Specifically, provide standard-sized flange and coupling assemblies. Both the flanges and couplings are made of high-strength alloy steel and have pre-set positioning holes and threaded holes for assembling the metal diaphragm disc.

[0061] Step 2: Provide an upper sealing membrane 1, an intermediate membrane 2, and a lower sealing membrane 3. Specifically, provide three metal membranes: the upper sealing membrane 1 and the lower sealing membrane 3 are made of titanium foil with a thickness of 0.08 mm, and the intermediate membrane 2 is made of SUS316 stainless steel with a thickness of 0.2 mm.

[0062] Step 3: Process multiple microgrooves 5 in the radial direction on the intermediate layer membrane 2. Specifically, multiple microgrooves 5 are processed in the radial direction on the surface of the intermediate layer membrane 2 using laser etching technology, and multiple small branch grooves 6 connected to the microgrooves 5 are designed in the root region 21. The width of the microgrooves 5 is about 200 micrometers, the width of the branch grooves 6 is 50 micrometers, and the depth of the grooves is 50 micrometers. The grooves have a circular arc cross-section.

[0063] Step 4: Inject liquid metal into the micro-groove 5 to form a liquid metal channel. Specifically, gallium indium tin alloy liquid metal is uniformly injected into the micro-groove 5 network by dripping and capillary drainage to form a closed liquid metal channel.

[0064] Step 5: Attach the upper sealing membrane 1 and the lower sealing membrane 3 to the upper and lower sides of the middle membrane 2, and seal the microgroove 5 to form a metal membrane disk. Specifically, the encapsulation and bonding between the multiple membranes are achieved through a hot-press welding process, ensuring good sealing of the microgroove 5 and preventing leakage of liquid metal.

[0065] Step 6: Prepare connecting holes 4 in the edge area of ​​the metal film disk. Specifically, in the edge area of ​​the metal film disk after welding, use a CNC drilling machine to process 6 symmetrically distributed connecting holes, and set an arc-shaped chamfer structure on the outer edge of each hole with a chamfer radius of 0.3mm to reduce stress concentration.

[0066] Step 7: Assemble the metal diaphragm disc between the flange and the coupling, and secure it with bolts. Specifically, assemble the prepared metal diaphragm disc between the flange and the coupling, and secure it with high-strength bolts to complete the assembly of the integral coupling.

[0067] Preferably, the connecting hole on one side of the metal diaphragm disk is a standard circular hole with a diameter of 4.5 mm, providing precise positioning. The connecting hole on the other side is an elliptical hole, with its major axis arranged along the radial direction of the diaphragm disk. The major axis length is 6.0 mm, the minor axis length is 4.5 mm, and the cross-sectional profile is a smoothly transitioning elliptical structure. This structural design takes into account the connection requirements of rigid positioning on one side and flexible release on the other side. It is beneficial for the diaphragm disk to absorb radial micro-displacements caused by thermal expansion, assembly errors, or eccentric loads during actual operation, thereby reducing the stress concentration in the connection area and mitigating the fatigue accumulation effect in the root region. At the same time, the circular hole provides a precise centering reference to ensure the coaxiality accuracy of the coupling, while the elliptical hole improves the compliance and service reliability of the structure by extending the degrees of freedom, making it particularly suitable for high-speed rotation or operating conditions with frequent thermal changes.

[0068] Preferably, the flange material has a hardness gradient structure that gradually decreases from the center to the outer edge. That is, the central region uses a high-hardness material to withstand axially transmitted torque and concentrated loads, while the material gradually transitions to a lower hardness material or structure towards the outer diameter, providing better compliance and cushioning. This hardness gradient design helps achieve a smooth transition between rigidity and flexibility, reducing stress concentration in the root region caused by sudden changes in rigidity during operation, improving the fatigue life of the diaphragm edge connection area and the overall dynamic stability of the coupling. Simultaneously, the hardness gradient structure can alleviate the problem of thermal expansion and contraction mismatch between different materials or components, enhancing the long-term service reliability of the entire assembly system, especially suitable for high-end equipment subjected to complex thermo-mechanical coupling loads.

[0069] In summary, this invention provides a novel and high-performance metal diaphragm coupling and its processing method. It employs a three-layer stacked structure: an upper closed diaphragm 1, an intermediate diaphragm 2 with microgrooves 5, and a lower closed diaphragm 3. A network of liquid metal microgrooves is embedded in the root region 21 of the intermediate diaphragm 2, constructing a closed liquid metal microcavity with stress adaptive adjustment capability. This invention is particularly suitable for precision transmission systems operating under high speed, heavy load, severe temperature differences, or complex conditions, possessing advantages such as high reliability, long lifespan, and engineerability, and has broad application prospects.

[0070] The above description is merely a preferred embodiment of this application and is not intended to limit this application. 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 metal bellows coupling comprising a flange plate, a coupling hub, a metal bellows disposed between the flange plate and the coupling hub, characterized in that: The metal film disc comprises an upper layer of closed diaphragm, an intermediate layer of diaphragm and a lower layer of closed diaphragm, the upper layer of closed diaphragm, the intermediate layer of diaphragm and the lower layer of closed diaphragm are all metal, at least one side surface of the intermediate layer of diaphragm is provided with a plurality of micro grooves arranged along a predetermined path, the micro grooves are filled with liquid metal, the upper layer of closed diaphragm and the lower layer of closed diaphragm are respectively arranged on the upper and lower sides of the intermediate layer of diaphragm for closing the micro grooves, forming a closed liquid metal micro cavity structure, wherein the micro grooves and the filled liquid metal are only arranged in the root area of the intermediate layer of diaphragm.

2. The metal bellows coupling as set forth in claim 1, wherein: The thickness of the upper layer of closed diaphragm and the lower layer of closed diaphragm is 0.05-0.12 mm, and the thickness of the intermediate layer of diaphragm is 0.1-0.3 mm.

3. The metal vee disc coupling of claim 1 wherein: The micro grooves are in a radial strip structure, extending from the center of the intermediate layer of diaphragm to the outer radial direction.

4. The metal vee disc coupling of claim 1 wherein: The groove depth of the micro grooves is 10-100 microns, the groove width is 50-300 microns, and the groove cross section is rectangular or circular arc.

5. The metal vee disc coupling of claim 1 wherein: The liquid metal is gallium indium tin alloy or gallium indium alloy.

6. The metal vee disc coupling of claim 1 wherein: In the root area of the intermediate layer of diaphragm, the two sides of the micro grooves are provided with a plurality of branch grooves communicating with the micro grooves, and the width of the branch grooves is smaller than the width of the micro grooves.

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