A limited angle magnetic coupling with a fork and a working method thereof

Abstract

This invention provides a fork-type limited-angle magnetic coupler and its operating method, relating to the field of magnetic drive technology. The fork-type limited-angle magnetic coupler includes an outer rotor assembly with multiple outer rotor magnetic poles distributed circumferentially; an inner rotor assembly coaxially disposed inside the outer rotor assembly, the inner rotor assembly having multiple inner rotor magnetic poles distributed circumferentially, the inner rotor magnetic poles radially opposite the outer rotor magnetic poles to form magnetic coupling; and a limiting assembly including a fork and a toothed component. The fork is disposed on the outer rotor assembly, and the toothed component is disposed on the inner rotor assembly, with the fork and toothed component engaging in a plug-in fit. Compared to existing technologies, the fork-type limited-angle magnetic coupler of this invention has the advantages of preventing angle deviation from exceeding a safety threshold, thus preventing step loss, and improving the stability and reliability of the transmission system; it also provides a mechanical protection mechanism under overload conditions to ensure safe system operation.

Description

Technical Field

[0001] This invention relates to the field of magnetic drive technology, and more specifically, to a fork-type limited-angle magnetic coupler and its working method. Background Technology

[0002] Permanent magnet couplings, as key devices for non-contact torque transmission utilizing the magnetic force between permanent magnets, have wide applications in industrial transmission systems. However, traditional permanent magnet couplings face multiple technical bottlenecks in actual operation. The startup process must maintain a strictly slow acceleration; if the input speed changes too rapidly, the input and output speeds will not be synchronized, leading to a loss of synchronization and sudden stall on the output side, seriously threatening the reliability of continuous system operation. When the transmitted torque exceeds the device's tolerance limit, the loss of synchronization problem occurs frequently, causing the output shaft to stop instantaneously, plunging the entire transmission system into an unstable state. In high-speed applications such as aerospace propulsion systems, the requirement for rapid startup demands a starting torque significantly exceeding the rated value. Traditional couplings must reserve excessive torque margins to meet this requirement, directly resulting in a significant increase in device size and weight. Simultaneously, the inherent limitations of the centrifugal force tolerance of the rotating material further restrict the potential for increasing the maximum speed due to the expansion of volume and weight, placing almost stringent requirements on manufacturing processes such as dynamic balancing accuracy, magnet fixing strength, and air gap uniformity. More significantly, traditional magnetic couplers completely lack an effective constraint mechanism for the relative rotation angle between the input and output shafts. When the rotation angle deviation exceeds the safety threshold, the system is highly susceptible to losing synchronization, resulting in uncontrollable phase drift between the input and output shafts, ultimately leading to transmission failure. This lack of rotation angle transmission capability is particularly dangerous under dynamic load changes or emergency conditions, making traditional devices unable to meet the stringent requirements of modern high-speed systems for rapid response and stable operation. Summary of the Invention

[0003] The purpose of this invention is to provide a fork-type limited-angle magnetic coupler, which has the advantages of preventing the angle deviation from exceeding the safety threshold and causing step loss, improving the stability and reliability of the transmission system; and providing a mechanical protection mechanism under overload conditions to ensure the safe operation of the system.

[0004] This invention provides a fork-type finite-angle magnetic coupler, comprising: An outer rotor assembly having multiple outer rotor magnetic poles distributed circumferentially; An inner rotor assembly is coaxially disposed inside the outer rotor assembly. The inner rotor assembly has a plurality of inner rotor magnetic poles distributed circumferentially. The inner rotor magnetic poles are radially opposite to the outer rotor magnetic poles to form magnetic coupling. A limiting component, comprising a shift fork and a toothed component, wherein the shift fork is disposed on the outer rotor assembly and the toothed component is disposed on the inner rotor assembly, and the shift fork and the toothed component are inserted into each other to limit the relative rotation angle between the outer rotor assembly and the inner rotor assembly.

[0005] The present invention provides a fork-type limited-angle magnetic coupler, which, compared with the prior art, has the following beneficial effects, but is not limited to: The fork-type limited-angle magnetic coupler of this invention effectively limits the relative rotation angle between the outer and inner rotor assemblies by setting a limiting component between the outer and inner rotor assemblies. The fork component of this limiting component engages with the toothed component, thus limiting the relative rotation angle between the outer and inner rotor assemblies. Therefore, while maintaining the flexible transmission characteristics of magnetic coupling, reliable mechanical limiting protection is provided to prevent step loss when the transmitted torque exceeds the rated range. This structure helps improve the dynamic stability of the coupler under high-speed, rapid start-up conditions and overcomes the shortcomings of traditional magnetic couplers in rotation angle control, thereby improving the reliability and adaptability of the system.

[0006] Optionally, the shift fork is a ring structure, and the inner circumferential sidewall of the shift fork is provided with multiple shift fork structures at intervals; the toothed groove is a ring structure, and the outer circumferential sidewall of the toothed groove is provided with multiple toothed groove structures at intervals; the shift fork structure is inserted into the toothed groove structure.

[0007] Optionally, the centerline of the outer rotor magnetic pole coincides with the centerline of the shift fork structure, and the centerline of the inner rotor magnetic pole coincides with the centerline of the toothed structure; the limiting angle between the shift fork structure and the toothed structure is less than or equal to a preset safety deflection angle.

[0008] Optionally, the limiting surfaces where the shift fork structure and the toothed groove structure contact each other are made of steel or silicone material; the shift fork structure or the toothed groove structure is made of hard nylon material.

[0009] Optionally, the outer rotor assembly includes an outer rotor core and an outer rotor housing. The outer rotor core has a circular ring structure, and a plurality of outer rotor magnetic poles are arranged on the circumferential inner sidewall of the outer rotor core. The circumferential outer sidewall of the outer rotor core is keyed to the outer rotor housing. The shift fork is connected to the outer rotor housing by bolts.

[0010] Optionally, the inner rotor assembly includes an inner rotor core, which is a ring structure, and a plurality of inner rotor magnetic poles are arranged on the circumferential outer wall of the inner rotor core, and the toothed members are coaxially connected to the inner rotor core.

[0011] Optionally, the inner rotor magnet is an inner rotor permanent magnet, and the outer surface of the inner rotor permanent magnet is wrapped with a carbon fiber protective layer.

[0012] Optionally, the inner rotor assembly includes an inner rotor core having a plurality of salient poles distributed circumferentially, the salient poles serving as the magnetic poles of the inner rotor, and no permanent magnets are disposed on the inner rotor core.

[0013] Optionally, the number of pole pairs of the outer rotor magnetic pole and the inner rotor magnetic pole are equal, and the axial length of the outer rotor magnetic pole and the inner rotor magnetic pole are the same; there is a working air gap between the outer rotor magnetic pole and the inner rotor magnetic pole.

[0014] In addition, the present invention also provides a method for operating a fork-type finite-angle magnetic coupler, based on the fork-type finite-angle magnetic coupler as described above, the method comprising: One of the outer rotor assembly and the inner rotor assembly is driven to rotate, and the other is driven to rotate synchronously through the magnetic coupling between the magnetic poles of the outer rotor and the magnetic poles of the inner rotor. When the transmitted torque is within the rated transmitted torque range, the outer rotor assembly and the inner rotor assembly maintain non-contact flexible magnetic force transmission. When the transmitted torque exceeds the rated transmitted torque range and causes the relative deflection angle to reach the limit angle, the shift fork and the toothed part make mechanical contact, and the outer rotor assembly and the inner rotor assembly are converted into a purely mechanical connection to transmit torque. When the transmitted torque returns to the rated transmitted torque range, the outer rotor assembly and the inner rotor assembly automatically resume flexible magnetic force transmission. Attached Figure Description

[0015] Figure 1 This is an exploded view of a fork-type finite-angle magnetic coupler according to an embodiment of the present invention; Figure 2 This is an assembly diagram of the fork-type finite-angle magnetic coupler according to an embodiment of the present invention; Figure 3 This is a schematic diagram of the dual-excitation scheme according to an embodiment of the present invention; Figure 4 This is a schematic diagram of the single-sided excitation scheme according to an embodiment of the present invention.

[0016] Explanation of reference numerals in the attached figures: 1. Outer rotor magnetic pole; 2. Inner rotor magnetic pole; 3. Shift fork; 31. Shift fork structure; 4. Gear; 41. Gear structure; 5. Outer rotor core; 6. Outer rotor housing; 7. Inner rotor core; 71. Salient pole; 8. Carbon fiber protective layer. Detailed Implementation

[0017] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0018] In the description of this invention, the orientations or positional relationships indicated by terms such as "up," "down," "left," "right," "top," "bottom," "front," "back," "inner," and "outer" are based on the orientations or positional relationships shown in the accompanying drawings and are used only for the convenience of describing this invention. They are not intended to indicate or imply that the device referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as limiting the scope of protection of this invention.

[0019] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0020] In the description of this specification, references to terms such as "embodiment," "one embodiment," and "one implementation" indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or implementation is included in at least one embodiment or implementation of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or implementation. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or implementations.

[0021] like Figure 1 and Figure 2 As shown, the fork-type finite-angle magnetic coupler of this invention includes: An outer rotor assembly having multiple outer rotor magnetic poles 1 distributed circumferentially; An inner rotor assembly is coaxially disposed inside the outer rotor assembly. The inner rotor assembly has a plurality of inner rotor magnetic poles 2 distributed circumferentially. The inner rotor magnetic poles 2 and the outer rotor magnetic poles 1 are radially opposite to form magnetic coupling. A limiting component, comprising a shift fork 3 and a toothed groove 4, wherein the shift fork 3 is disposed on the outer rotor assembly and the toothed groove 4 is disposed on the inner rotor assembly, and the shift fork 3 and the toothed groove 4 are inserted into each other to limit the relative rotation angle between the outer rotor assembly and the inner rotor assembly.

[0022] In this embodiment, in conjunction with the appendix Figure 1 and attached Figure 2 As shown, the outer rotor assembly refers to the external rotating component in the magnetic coupler that carries the outer rotor magnetic pole 1 and connects to an external drive or load. The inner rotor assembly refers to the internal rotating component in the magnetic coupler that carries the inner rotor magnetic pole 2 and is coaxially arranged with the outer rotor assembly, transmitting torque through magnetic force. The outer rotor magnetic pole 1 refers to the magnetic component on the outer rotor assembly that generates a magnetic force with the inner rotor magnetic pole 2. The inner rotor magnetic pole 2 refers to the magnetic component on the inner rotor assembly that generates a magnetic force with the outer rotor magnetic pole 1. Magnetic coupling refers to the mechanism by which the outer rotor magnetic pole 1 and the inner rotor magnetic pole 2 achieve non-contact torque transmission through magnetic field interaction. The limiting assembly refers to the mechanical structure used to limit the relative rotation angle between the outer rotor assembly and the inner rotor assembly to prevent excessive relative displacement. The shift fork 3 is a component in the limiting assembly, with a protruding structure for mechanically engaging with the toothed part 4. The toothed component 4, which is another part of the limiting assembly, has a groove structure for mechanically engaging with the shift fork component 3.

[0023] This embodiment provides a fork-type limited-angle magnetic coupler. The coupler includes an outer rotor assembly with multiple circumferentially distributed outer rotor magnetic poles 1. These outer rotor magnetic poles 1 can be fixed to the inner surface of the outer rotor assembly, for example, by adhesive bonding, mechanical snap-fitting, or embedded mounting. The outer rotor assembly can be constructed as a cylindrical or annular structure to adapt to different installation requirements.

[0024] The inner rotor assembly is coaxially disposed inside the outer rotor assembly. The inner rotor assembly has multiple circumferentially distributed inner rotor magnetic poles 2. These inner rotor magnetic poles 2 are radially opposite to the outer rotor magnetic poles 1, thus forming magnetic coupling. The inner rotor magnetic poles 2 can be fixed to the outer surface of the inner rotor assembly, in a similar manner to the outer rotor magnetic poles 1. The inner rotor assembly can be constructed as a ring structure, with its outer diameter matching the inner diameter of the outer rotor assembly to ensure the radial relative relationship between the magnetic poles.

[0025] This fork-type limited-angle magnetic coupler also includes a limiting assembly. This limiting assembly consists of a fork 3 and a toothed member 4. The fork 3 is mounted on the outer rotor assembly and is connected to it, for example, by welding, riveting, or integral molding. The toothed member 4 is mounted on the inner rotor assembly, and its connection method can be similar to that of the fork 3.

[0026] The shift fork 3 and the toothed member 4 are engaged in a plug-in fit. Specifically, the shift fork 3 may have one or more protruding structures, while the toothed member 4 has one or more corresponding groove structures. When the outer rotor assembly and the inner rotor assembly rotate relative to each other, the protruding structure of the shift fork 3 abuts against the inner sidewall of the groove structure of the toothed member 4. For example, when the relative rotation angle reaches a preset limit value, the sidewall of the shift fork 3 and the toothed member 4 will make mechanical contact, thereby ensuring that the outer rotor assembly and the inner rotor assembly rotate synchronously. This mechanical contact can prevent the magnetic coupler from losing synchronization under overload conditions and provide additional torque transmission capability. The shape and number of the shift fork 3 and the toothed member 4 can be designed according to actual application requirements, such as using various geometric shapes such as rectangles, trapezoids, or arcs.

[0027] It should be noted that the insertion and engagement of the shift fork 3 and the toothed groove 4 means that the protruding structure (shift fork structure 31) of the shift fork 3 extends into the groove structure (toothed groove structure 41) of the toothed groove 4. The width of the groove structure of the toothed groove 4 is greater than that of the shift fork 3. Only after the outer rotor assembly and the inner rotor assembly rotate relative to each other and reach a certain angle will the protruding structure of the shift fork 3 contact the groove structure of the toothed groove 4.

[0028] The fork-type limited-angle magnetic coupler of this embodiment effectively limits the relative rotation angle between the outer and inner rotor assemblies by setting a limiting component between them. The fork 3 and the toothed groove 4 of this limiting component engage in a plug-in fit. Thus, while maintaining the flexible transmission characteristics of magnetic coupling, reliable mechanical limiting protection is provided to prevent step loss when the transmitted torque exceeds the rated range. This structure helps improve the dynamic stability of the coupler under high-speed, rapid start-up conditions and overcomes the shortcomings of traditional magnetic couplers in angle control, thereby improving the reliability and adaptability of the system.

[0029] Optionally, the shift fork 3 is a ring structure, and the inner circumferential sidewall of the shift fork 3 is provided with a plurality of shift fork structures 31 at intervals; the toothed groove 4 is a ring structure, and the outer circumferential sidewall of the toothed groove 4 is provided with a plurality of toothed groove structures 41 at intervals; the shift fork structure 31 is inserted into the toothed groove structure 41.

[0030] In this embodiment, in conjunction with the appendix Figure 2As shown, the shift fork 3 is designed in a circular shape, providing a stable mounting base and uniform force distribution. Multiple shift fork structures 31 are spaced apart on the circumferential inner wall of the shift fork 3. These shift fork structures 31 are specific limiting units that cooperate with the toothed groove structure 41; they are distributed circumferentially along the inner wall of the ring, forming a series of protruding parts. This spaced arrangement ensures effective limiting at different angles and allows for a certain range of relative rotation before limiting occurs. The cross-sectional shape of the shift fork structure 31 can be designed as rectangular, trapezoidal, arc-shaped, etc., according to actual needs; its number and size directly affect the limiting accuracy and load-bearing capacity.

[0031] Meanwhile, the toothed part 4 is also designed as a ring structure, corresponding in shape to the shift fork part 3, to provide a stable mounting base and uniform force distribution. Multiple toothed structures 41 are spaced apart on the circumferential outer wall of the toothed part 4. These toothed structures 41 are grooves for accommodating the shift fork structure 31, and they are distributed circumferentially along the outer wall of the ring.

[0032] When the shift fork structure 31 is inserted into the toothed groove structure 41, a core mechanical engagement mechanism for limiting the rotation angle is formed. During relative rotation between the outer rotor assembly and the inner rotor assembly, the shift fork structure 31 moves within the internal space of the toothed groove structure 41. Once the relative rotation reaches a preset limit angle, the sidewall of the shift fork structure 31 makes mechanical contact with the sidewall of the toothed groove structure 41, effectively preventing further relative rotation. This insertion engagement provides a clear mechanical limit point, ensuring the accuracy and reliability of the rotation angle limitation.

[0033] Optionally, the centerline of the outer rotor magnetic pole 1 coincides with the centerline of the shift fork structure 31, and the centerline of the inner rotor magnetic pole 2 coincides with the centerline of the toothed structure 41; the limiting angle between the shift fork structure 31 and the toothed structure 41 is less than or equal to a preset safety deflection angle.

[0034] In this embodiment, the centerline of the outer rotor magnetic pole 1 coincides with the centerline of the shift fork structure 31. This means that, circumferentially, the geometric central axis of the outer rotor magnetic pole 1 and the geometric central axis of the shift fork structure 31 are at the same angular position. This design ensures a direct and synchronous angular correspondence between the main body of magnetic coupling (outer rotor magnetic pole 1) and the main body of mechanical limiting (shift fork structure 31). In practical implementation, during the assembly of the outer rotor assembly, the shift fork 3 can be fixed to the outer rotor assembly using a precise positioning mechanism or marking, so that the centerline of the shift fork structure 31 is aligned circumferentially with the centerline of the outer rotor magnetic pole 1. For example, if the outer rotor magnetic poles 1 are evenly distributed, then the shift fork structures 31 should also be evenly distributed and aligned with the outer rotor magnetic poles 1.

[0035] Simultaneously, the centerline of the inner rotor magnetic pole 2 coincides with the centerline of the toothed structure 41. Similar to the outer rotor assembly, this ensures that the geometric center axis of the inner rotor magnetic pole 2 is aligned circumferentially with the geometric center axis of the toothed structure 41. This alignment ensures that the magnetic coupling and mechanical limiting action on the inner rotor side maintain a synchronous angular correspondence. In practical implementation, this can be achieved by precisely fixing the toothed component 4 to the inner rotor assembly during assembly, thus aligning the centerline of the toothed structure 41 with the centerline of the inner rotor magnetic pole 2 circumferentially.

[0036] Furthermore, the limiting angle between the shift fork structure 31 and the toothed structure 41 is less than or equal to the preset safety deflection angle. The limiting angle refers to the maximum relative rotation angle allowed between the shift fork structure 31 and the toothed structure 41 during circumferential relative movement, from an initial non-contact state to mechanical contact. The preset safety deflection angle refers to the maximum relative rotation angle that the outer rotor magnetic pole 1 and the inner rotor magnetic pole 2 can withstand during normal operation of the magnetic coupler. Exceeding this angle may lead to demagnetization of the magnetic poles, a decrease in magnetic coupling performance, or structural damage. By setting the limiting angle to be less than or equal to the preset safety deflection angle, it can be ensured that when the magnetic coupler deflects due to overload, the mechanical limiting mechanism can intervene before the magnetic poles reach their safety limit, thereby effectively protecting the magnetic poles. This limiting angle can be achieved by precisely designing the circumferential width of the shift fork structure 31 and the toothed structure 41, as well as the gap between them. The preset safety deflection angle can be determined through theoretical calculations, simulation analysis, or experimental testing, based on factors such as the magnetic properties of the magnetic pole material, the magnetic circuit design, and the structural strength.

[0037] Optionally, the limiting surfaces of the shift fork structure 31 and the toothed groove structure 41 that come into contact with each other are made of steel or silicone material; the shift fork structure 31 or the toothed groove structure 41 is made of hard nylon material.

[0038] In this embodiment, the limiting surfaces where the shift fork structure 31 and the toothed groove structure 41 contact each other refer to the areas where mechanical contact occurs between the shift fork structure 31 and the toothed groove structure 41 when the transmitted torque exceeds the rated range during the operation of the magnetic coupler, causing relative deflection between the outer rotor assembly and the inner rotor assembly and reaching the limiting angle. These limiting surfaces are key parts that directly bear impact loads and friction. Using steel as the limiting surface utilizes the excellent strength, hardness, and wear resistance of steel to resist high-intensity impacts and long-term friction, thereby ensuring the structural integrity and reliability of the limiting mechanism under extreme working conditions. This can be achieved by embedding steel bushings, coating steel wear-resistant layers, or directly making the contact parts into steel components on the main body of the shift fork structure 31 or the toothed groove structure 41. On the other hand, using silicone material as the limiting surface utilizes the good elasticity, buffering, and shock absorption properties of silicone material to effectively absorb the impact energy during mechanical contact, significantly reduce impact noise, and reduce damage to components. Silicone materials are typically applied to limiting surfaces in the form of gaskets, coatings, or inserts. Their flexibility helps to provide some cushioning at the moment of contact, avoiding hard impacts.

[0039] Meanwhile, the shift fork structure 31 or the toothed groove structure 41 is made of hard nylon material. Hard nylon materials, such as engineering plastics like PA66 and PA6, have high strength, rigidity, and wear resistance, while also being lightweight and possessing certain self-lubricating properties. The main body of the shift fork structure 31 or the toothed groove structure 41 can be made of hard nylon material through injection molding or machining. This material selection not only provides sufficient structural support and load-bearing capacity for the limiting mechanism, but its inherent elasticity also helps to further absorb impact, reduce the overall inertia of the mechanism, and decrease frictional wear between the mechanism and the limiting surface material.

[0040] Optionally, the outer rotor assembly includes an outer rotor core 5 and an outer rotor housing 6. The outer rotor core 5 has a circular ring structure, and a plurality of outer rotor magnetic poles 1 are arranged on the circumferential inner sidewall of the outer rotor core 5. The circumferential outer sidewall of the outer rotor core 5 is keyed to the outer rotor housing 6. The shift fork 3 is connected to the outer rotor housing 6 by bolts.

[0041] In this embodiment, in conjunction with the appendix Figure 1As shown, the outer rotor assembly is designed to consist of two parts: an outer rotor core 5 and an outer rotor housing 6. The outer rotor core 5 is typically made of a material with good magnetic permeability, such as laminated silicon steel sheets or soft magnetic alloys, and has a ring structure to provide the necessary magnetic circuit for magnetic coupling. Multiple outer rotor magnetic poles 1, such as permanent magnets or electromagnetic coils, are precisely arranged and fixed on the circumferential inner wall of the outer rotor core 5 to ensure stable radial magnetic coupling with the inner rotor magnetic poles 2. The circumferential outer wall of the outer rotor core 5 is connected to the outer rotor housing 6 using a key connection. Key connection is a common mechanical connection method. It involves machining keyways on the shaft and hub (here, the outer rotor core 5 and the outer rotor housing 6) and inserting a key to achieve circumferential fixation between them, thereby effectively transmitting torque and preventing relative rotation. This connection method has advantages such as simple structure, convenient assembly and disassembly, and high load-bearing capacity. The outer rotor housing 6 is typically made of high-strength materials, such as steel or aluminum alloy. Its main functions are to provide structural support for the entire outer rotor assembly, protect the internal magnetic poles, and serve as the interface for connection with other components. The shift fork 3, a key part of the limiting assembly, is connected to the outer rotor housing 6 by bolts. Bolting is a removable fastening method; reliable fixation is achieved by passing bolts through pre-drilled holes in both the shift fork 3 and the outer rotor housing 6 and tightening nuts. This connection method allows for adjustment, replacement, or maintenance of the outer rotor assembly or the shift fork 3 as needed, while ensuring that the shift fork 3 can withstand impact loads during limiting operations.

[0042] Optionally, the inner rotor assembly includes an inner rotor core 7, which is a circular ring structure. A plurality of inner rotor magnetic poles 2 are arranged on the circumferential outer wall of the inner rotor core 7, and the toothed slot 4 is coaxially connected to the inner rotor core 7.

[0043] In this embodiment, in conjunction with the appendix Figure 1 and attached Figure 3As shown, the inner rotor core 7 is the core structural component of the inner rotor assembly, typically made of materials with good magnetic permeability (such as soft magnetic steel, laminated silicon steel sheets, etc.). Its main function is to provide a mounting base for the inner rotor magnetic poles 2 and form a magnetic flux loop, thereby enhancing the magnetic field strength and improving the efficiency of magnetic coupling. The inner rotor core 7 can be a monolithically machined ring structure, or assembled from multiple sector-shaped or segmented cores through mechanical connection or welding, to meet different design and manufacturing requirements. The inner rotor core 7 is designed as a ring structure, which ensures good balance of the inner rotor assembly during rotation and helps to achieve a uniform magnetic field distribution. This ring structure can be solid or lightweight (e.g., with spokes) to reduce the overall weight while maintaining structural strength. Multiple inner rotor magnetic poles 2 are evenly distributed along the outer circumference of the inner rotor core 7. These magnetic poles can be permanent magnets, securely mounted on the outer wall of the inner rotor core 7 by means of bonding, mechanical snap-fitting, pressing, or bolting. The toothed component 4, as a key part of the limiting assembly, has a structure (e.g., a ring structure with multiple toothed structures 41 spaced apart on the circumferential outer wall) that coincides with the rotation axis of the inner rotor core 7 and is firmly fixed to the inner rotor core 7. The connection method between the toothed component 4 and the inner rotor core 7 can be varied. For example, they can be integrally cast or machined to achieve the most compact and reliable structure; they can also be connected by mechanical means such as bolts, keys, interference fits, or welding to ensure that the toothed component 4 can rotate synchronously with the inner rotor core 7 when mechanical limiting occurs, and effectively transfer the impact load to the inner rotor core 7.

[0044] Optionally, the inner rotor magnetic pole 2 is an inner rotor permanent magnet, and the outer surface of the inner rotor permanent magnet is wrapped with a carbon fiber protective layer 8.

[0045] In this embodiment, in conjunction with the appendix Figure 3As shown, the inner rotor permanent magnet refers to a magnetic material capable of generating and maintaining a magnetic field. Rare-earth permanent magnet materials with high remanence and high coercivity, such as neodymium iron boron (NdFeB) or samarium cobalt (SmCo) permanent magnets, are typically selected. After pre-magnetization, these permanent magnets provide a stable and strong magnetic field, ensuring efficient magnetic coupling between the inner and outer rotor assemblies. In practical applications, these permanent magnets can be fabricated into arc-shaped tiles, rectangular blocks, etc., and precisely installed and fixed to the circumferential outer wall of the inner rotor core 7, for example, through bonding, mechanical clamping, or embedding, to ensure their positional stability under high-speed rotation. The carbon fiber protective layer 8 is a structural layer composed of high-strength, high-modulus carbon fiber bundles and a resin matrix (such as epoxy resin). This protective layer is tightly wrapped around the outer surface of the inner rotor permanent magnet through a precise winding process. The superior mechanical properties of carbon fiber significantly enhance the overall mechanical strength and impact resistance of permanent magnets, effectively resisting the enormous centrifugal force generated during high-speed rotation and preventing the permanent magnets from cracking or detaching due to stress concentration. Furthermore, this protective layer provides a physical barrier against external environmental corrosion, thereby extending the service life of the permanent magnets and ensuring the long-term stable operation of the magnetic coupler. The winding process typically employs automated equipment, controlling the winding angle and tension to form a uniform and dense protective layer, which is then cured to create a robust composite structure.

[0046] Optionally, the inner rotor assembly includes an inner rotor core 7, the inner rotor core 7 having a plurality of salient poles 71 distributed circumferentially, the salient poles 71 serving as the inner rotor magnetic poles 2.

[0047] In this embodiment, in conjunction with the appendix Figure 4 As shown, the inner rotor core 7 is a key structural component of the inner rotor assembly, typically made of magnetically conductive materials, such as laminated silicon steel sheets or cast from soft magnetic materials. Its main function is to provide a magnetic flux path. The salient poles 71 refer to the portions that protrude outward at certain intervals on the circumferential outer surface of the inner rotor core 7. These salient poles 71, through their geometry and material properties, form magnetic poles under the influence of a magnetic field, thereby achieving magnetic coupling with the outer rotor magnetic poles 1. The number and distribution of the salient poles 71 are usually matched with the number of outer rotor magnetic poles 1 to ensure good magnetic force transmission. Here, the salient poles 71 directly function as the inner rotor magnetic poles 2, meaning that there is no need to install additional permanent magnets or excitation coils; the salient poles 71 themselves can induce magnetic poles under the influence of a magnetic field, achieving magnetic coupling. This design simplifies the structure of the inner rotor assembly and reduces manufacturing costs.

[0048] Optionally, the number of pole pairs of the outer rotor magnetic pole 1 and the inner rotor magnetic pole 2 are equal, and the axial length of the outer rotor magnetic pole 1 and the inner rotor magnetic pole 2 is the same; there is a working air gap between the outer rotor magnetic pole 1 and the inner rotor magnetic pole 2.

[0049] In this embodiment, in conjunction with the appendix Figure 3 As shown, the number of pole pairs of the outer rotor magnetic pole 1 and the inner rotor magnetic pole 2 are equal, meaning that the number of pole pairs formed by all the outer rotor magnetic poles 1 on the outer rotor assembly is consistent with the number of pole pairs formed by all the inner rotor magnetic poles 2 on the inner rotor assembly. The number of pole pairs refers to the number of N poles and S poles on a magnet; a pair of poles contains one N pole and one S pole. By ensuring that the number of pole pairs is equal, the circumferential magnetic field distribution of the outer rotor magnetic poles 1 and the inner rotor magnetic poles 2 can be well matched, forming a stable and efficient magnetic circuit. This helps to maximize the utilization of magnetic force, reduce magnetic leakage, and thus improve the efficiency and strength of magnetic coupling. In actual manufacturing, this is usually achieved by accurately calculating and arranging the number of poles during the design phase. For example, if the outer rotor magnetic pole 1 has 10 poles (5 pairs), then the inner rotor magnetic pole 2 should also have 10 poles (5 pairs), with N poles and S poles alternating to ensure the uniformity of magnetic field interaction.

[0050] Simultaneously, the outer rotor magnetic pole 1 and the inner rotor magnetic pole 2 have the same axial length, meaning that the dimensions of the outer rotor magnetic pole 1 and the inner rotor magnetic pole 2 are consistent along the rotation axis. This design aims to maximize the effective coupling area of ​​the outer rotor magnetic pole 1 and the inner rotor magnetic pole 2 in the axial direction, thereby ensuring that the magnetic coupling effect is uniform and sufficient along the entire axial length. Inconsistent axial lengths may lead to uneven distribution of the magnetic field in the axial direction, resulting in unnecessary axial magnetic force, increased bearing load, and reduced coupling efficiency. By precise machining and assembly, such as using CNC machine tools to cut or grind the magnetic poles and using high-precision measuring tools for inspection, the axial dimensions of the inner and outer rotor magnetic poles can be kept consistent.

[0051] Furthermore, there is a working air gap between the outer rotor magnetic pole 1 and the inner rotor magnetic pole 2. The working air gap refers to the radial non-contact space between the outer rotor magnetic pole 1 and the inner rotor magnetic pole 2. This working air gap is crucial for the non-contact torque transmission of the magnetic coupler, allowing the inner and outer rotors to move relative to each other without mechanical friction, thereby effectively avoiding wear, reducing operating noise, and extending the equipment's service life. The size of the working air gap directly affects the strength of the magnetic coupling and the stiffness of the coupler. An air gap that is too small may lead to mechanical interference, while an air gap that is too large will significantly weaken the magnetic force. Typically, the size of the working air gap is optimized based on factors such as the required transmitted torque, the magnetic properties of the magnetic pole material, and structural strength, and is ensured through precision machining and assembly tolerance control. For example, a stable working air gap can be maintained by placing a non-magnetic isolation ring between the inner and outer rotors or by precisely controlling the bearing clearance.

[0052] In summary, the fork-type finite-angle magnetic coupler of the present invention has both bilateral excitation and single-sided excitation schemes. Specifically: in conjunction with the attached... Figure 1 and attached Figure 3 As shown, this is a bilateral excitation scheme, which adopts a radial magnetic circuit structure. The number of magnetic poles of the outer rotor and the inner rotor are equal, and the number of magnetic pole pairs P=N, where N is a natural number (N=1, 2, 3...). The opposite magnetic poles of the outer rotor and the inner rotor are arranged opposite each other, and the axial length of the magnetic poles of both are the same, thus forming a permanent magnet coupler structure without axial magnetic pull.

[0053] A fork-and-groove structure (fork 3 and groove 4) is provided between the outer rotor and the inner rotor to limit the angular position. The number of teeth (fork structure 31) and the number of grooves (groove structure 41) are equal, both being P. The limited angular range is θ = ±180° / 2P. The centerline of the outer rotor magnetic pole 1 coincides with the centerline of the fork structure 31, and correspondingly, the centerline of the inner rotor magnetic pole 2 coincides with the centerline of the groove structure 41.

[0054] The air gap δ between the outer rotor magnetic pole 1 and the inner rotor magnetic pole 2 is 0.5mm to 10mm. The radial tension generated by the magnetic poles on both sides constitutes the radial basic magnetic tension, denoted as 2Tm.

[0055] When the opposite magnetic poles of the outer and inner rotors are in a relatively aligned position, no torque is transmitted between them; when there is a position deflection angle θ between the opposite magnetic poles, the transmitted torque satisfies the following torque-angle characteristics: T = 2rFm × sinPθ = Tm × sinPθ In the formula, T is the transmitted torque, Fm is the magnetic pull force on one side of the foundation, r is the rotor radius, Tm is the maximum torque, and θ is the deflection angle.

[0056] When the deflection angle Pθ is within ±90°, the transmitted torque increases with increasing deflection angle, reaching its maximum value at Pθ = ±90°. Within this range, flexible magnetic force transmission is achieved between the outer and inner rotors. When the deflection angle Pθ exceeds ±90°, the transmitted torque decreases with increasing deflection angle. At this point, the shift fork 3 exceeds its limit range, and mechanical contact occurs between the outer and inner rotors, transitioning to a purely mechanical connection. If the actual transmitted torque is less than the maximum torque Tm, the coupler can automatically revert from a purely mechanical connection to flexible magnetic force transmission.

[0057] Based on the above characteristics, the rated transmission torque T is defined. N The expression is: T N =±Tm×sin(Pθ)=±Tm×sin(90° / P) To improve reliability, the limiting angle of the shift fork 3 is set to θc<±(90° / P-△θ), where △θ is 0.5°~5°.

[0058] Similarly, in conjunction with the appendix Figure 1 and attached Figure 4 As shown, the single-sided excitation scheme differs from the double-sided excitation scheme in that a fork-and-groove structure is provided between the outer and inner rotors to limit the angular position. The number of teeth (fork structure 31) and the number of grooves (groove structure 41) are equal, both being 2P. The limited angle range is 2θ = ±180° / 2P, that is, the limiting angle of the fork 3 is θc = ±90° / 2P. The centerline of the outer rotor magnetic pole 1 coincides with the centerline of the fork structure 31, and correspondingly, the centerline of the salient pole 71 of the inner rotor core 7 coincides with the centerline of the groove structure 41.

[0059] The air gap δ between the outer rotor magnetic pole 1 and the salient pole 71 is 0.5mm to 5mm. The radial tension between the outer rotor magnetic pole 1 and the salient pole 71 constitutes the radial basic magnetic tension, denoted as 2Tm.

[0060] When the outer rotor magnetic pole 1 and the salient pole 71 are in a positive alignment position, no torque is transmitted between the outer rotor and the inner rotor; when there is a position deflection angle θ between their center lines, torque will be transmitted between the outer rotor and the inner rotor, and the transmitted torque satisfies the following torque-angle characteristics: T=2rFm×sin(Pθ)=Tm×sin(2Pθ) In the formula, T is the transmitted torque, Fm is the magnetic pull force on one side of the foundation, r is the rotor radius, Tm is the maximum torque, and θ is the deflection angle.

[0061] When the deflection angle 2Pθ is within ±90°, the transmitted torque increases with increasing deflection angle, reaching its maximum value at 2Pθ = ±90°. Within this range, flexible magnetic force transmission is achieved between the outer and inner rotors. When the deflection angle 2Pθ exceeds ±90°, the transmitted torque decreases with increasing deflection angle. At this point, the shift fork exceeds its limit range, and mechanical contact occurs between the outer and inner rotors, transitioning to a purely mechanical connection. If the actual transmitted torque is less than the maximum torque Tm, the coupler can automatically revert from a purely mechanical connection to flexible magnetic force transmission.

[0062] Based on the above characteristics, the rated transmission torque T is defined. N The expression is: T N =±Tm×sin2Pθ=±Tm×sin(90° / 2P) To improve reliability, the limiting angle of the shift fork 3 should be set to θc < ± (90° / 2P - △θ), where △θ is 0.5° to 5°.

[0063] In addition, the present invention also provides a method for operating a fork-type finite-angle magnetic coupler, based on the fork-type finite-angle magnetic coupler as described above, the method comprising: Drive one of the outer rotor assembly and the inner rotor assembly to rotate, and through the magnetic coupling between the outer rotor magnetic pole 1 and the inner rotor magnetic pole 2, drive the other to rotate synchronously; When the transmitted torque is within the rated transmitted torque range, the outer rotor assembly and the inner rotor assembly maintain non-contact flexible magnetic force transmission. When the transmitted torque exceeds the rated transmitted torque range and causes the relative deflection angle to reach the limit angle, the shift fork 3 and the toothed part 4 make mechanical contact, and the outer rotor assembly and the inner rotor assembly are converted into a purely mechanical connection to transmit torque. When the transmitted torque returns to the rated transmitted torque range, the outer rotor assembly and the inner rotor assembly automatically resume flexible magnetic force transmission.

[0064] In this embodiment, by combining the flexible magnetic coupling transmission mechanism with the mechanical limiting protection structure in a dynamic switching manner, when the transmitted torque exceeds the rated range, the shift fork 3 and the toothed part 4 make mechanical contact to achieve a purely mechanical connection, thereby effectively avoiding the loss of synchronization and maintaining synchronous rotation. This achieves the effects of rapid start-up, preventing the expansion of angular deviation, and improving the dynamic stability of the system under high-speed conditions. Specifically, since the output side of a traditional magnetic coupler will stop rapidly when the torque exceeds the limit, this invention automatically triggers mechanical contact when the relative deflection angle reaches the limit angle through the plug-in engagement mechanism of the limiting component, ensuring the continuity of torque transmission. At the same time, when the torque returns to the rated range, the outer rotor assembly and the inner rotor assembly automatically resume flexible magnetic transmission, avoiding the vibration and wear problems caused by permanent mechanical connections in traditional structures. Furthermore, this working method utilizes the radially opposite arrangement of the outer rotor magnetic pole 1 and the inner rotor magnetic pole 2 to form a working air gap. Combined with the precise limiting angle design of the shift fork 3 and the toothed groove 4, it significantly reduces the difficulty of dynamic balancing during high-speed rotation, enabling the coupler to meet both lightweight and high reliability requirements in high-speed applications such as aircraft. In summary, this technical solution not only solves the problems of limited start-up speed and the risk of loss of synchronization, but also achieves active control of rotational deviation through a mechanical-magnetic dual-mode switching mechanism, providing a compact and dynamically responsive solution for high-speed, high-torque operating conditions.

[0065] While the present invention has been disclosed above, its scope of protection is not limited thereto. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention, and all such changes and modifications will fall within the scope of protection of the present invention.

Claims

1. A fork-type finite-angle magnetic coupler, characterized in that, include: An outer rotor assembly having multiple outer rotor magnetic poles distributed circumferentially (1). An inner rotor assembly is coaxially disposed inside the outer rotor assembly. The inner rotor assembly has a plurality of inner rotor magnetic poles (2) distributed circumferentially. The inner rotor magnetic poles (2) are radially opposite to the outer rotor magnetic poles (1) to form magnetic coupling. The limiting component includes a shift fork (3) and a toothed groove (4). The shift fork (3) is disposed on the outer rotor assembly, and the toothed groove (4) is disposed on the inner rotor assembly. The shift fork (3) and the toothed groove (4) are inserted and engaged to limit the relative rotation angle between the outer rotor assembly and the inner rotor assembly.

2. The fork-type finite-angle magnetic coupler according to claim 1, characterized in that, The shift fork (3) is a ring structure, and the inner sidewall of the shift fork (3) is provided with multiple shift fork structures (31) spaced apart; the toothed groove (4) is a ring structure, and the outer sidewall of the toothed groove (4) is provided with multiple toothed groove structures (41) spaced apart; the shift fork structure (31) is inserted into the toothed groove structure (41).

3. The fork-type finite-angle magnetic coupler according to claim 2, characterized in that, The centerline of the outer rotor magnetic pole (1) coincides with the centerline of the shift fork structure (31), and the centerline of the inner rotor magnetic pole (2) coincides with the centerline of the toothed structure (41); the limiting angle between the shift fork structure (31) and the toothed structure (41) is less than or equal to the preset safety deflection angle.

4. The fork-type finite-angle magnetic coupler according to claim 2, characterized in that, The limiting surfaces of the shift fork structure (31) and the toothed structure (41) that come into contact with each other are made of steel or silicone material; the shift fork structure (31) or the toothed structure (41) is made of hard nylon material.

5. The fork-type finite-angle magnetic coupler according to claim 1, characterized in that, The outer rotor assembly includes an outer rotor core (5) and an outer rotor housing (6). The outer rotor core (5) is a ring structure. Multiple outer rotor magnetic poles (1) are arranged on the inner circumferential sidewall of the outer rotor core (5). The outer circumferential sidewall of the outer rotor core (5) is keyed to the outer rotor housing (6). The shift fork (3) is connected to the outer rotor housing (6) by bolts.

6. The fork-type finite-angle magnetic coupler according to claim 5, characterized in that, The inner rotor assembly includes an inner rotor core (7), which is a ring structure. Multiple inner rotor magnetic poles (2) are arranged on the circumferential outer wall of the inner rotor core (7), and the toothed part (4) is coaxially connected to the inner rotor core (7).

7. The fork-type finite-angle magnetic coupler according to claim 6, characterized in that, The inner rotor magnetic pole (2) is an inner rotor permanent magnet, and the outer surface of the inner rotor permanent magnet is wrapped with a carbon fiber protective layer (8).

8. The fork-type finite-angle magnetic coupler according to claim 5, characterized in that, The inner rotor assembly includes an inner rotor core (7) having a plurality of salient poles (71) distributed circumferentially, the salient poles (71) serving as the inner rotor magnetic poles (2).

9. The fork-type finite-angle magnetic coupler according to claim 1, characterized in that, The number of pole pairs of the outer rotor magnetic pole (1) and the inner rotor magnetic pole (2) are equal, and the axial length of the outer rotor magnetic pole (1) and the inner rotor magnetic pole (2) is the same; there is a working air gap between the outer rotor magnetic pole (1) and the inner rotor magnetic pole (2).

10. A method for operating a fork-type finite-angle magnetic coupler, based on the fork-type finite-angle magnetic coupler as described in any one of claims 1-9, characterized in that, The working method includes: One of the outer rotor assembly and the inner rotor assembly is driven to rotate, and the other is driven to rotate synchronously through the magnetic coupling between the outer rotor magnetic pole (1) and the inner rotor magnetic pole (2); When the transmitted torque is within the rated transmitted torque range, the outer rotor assembly and the inner rotor assembly maintain non-contact flexible magnetic force transmission. When the transmitted torque exceeds the rated transmitted torque range and causes the relative deflection angle to reach the limit angle, the shift fork (3) and the toothed part (4) make mechanical contact, and the outer rotor assembly and the inner rotor assembly are converted into a purely mechanical connection to transmit torque; When the transmitted torque returns to the rated transmitted torque range, the outer rotor assembly and the inner rotor assembly automatically resume flexible magnetic force transmission.

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