Rotor assembly, stator assembly and axial flux motor

Abstract

The utility model relates to axial flux motor technical field, is a rotor assembly, stator subassembly and axial flux motor, and rotor assembly includes rotor support, permanent magnet and shaft sleeve, and the rotor support is fixedly installed on the outside of shaft sleeve upper end, stator subassembly includes stator support, winding and core, and the stator support includes installation cylinder and interval plate, and the inside of installation cylinder upper end is spaced apart and is uniformly distributed with a plurality of interval plates along the circumference, axial flux motor includes casing, motor shaft, upper bearing, lower bearing, rotor assembly, stator subassembly, end shaft sleeve, upper rotor assembly and lower rotor assembly, and the motor shaft of two ends in the casing outside is installed in the casing, and the upper bearing is established between the motor shaft upper part and the casing, and the lower bearing is established between the motor shaft lower part and the casing. The utility model is reasonable in structure and compact, convenient to use, through setting up multiple stator subassembly and multiple rotor assembly, and adopting the stacking structure, improve power density, have stable, efficient and power density big characteristics.

Description

Technical Field

[0001] This utility model relates to the field of axial flux motor technology, and is a rotor assembly, a stator assembly, and an axial flux motor. Background Technology

[0002] Axial flux motors, also known as disc motors or circular motors, are characterized by a magnetic flux path parallel to the rotation axis, a planar air gap, and a disc-shaped stator and rotor design that results in a flattened overall form. This technology, through optimized magnetic circuit design, significantly reduces size and weight while increasing torque density (torque per unit volume) and power density (power output per unit mass) under the same power conditions, making it an important development direction in modern motor technology. Its planar air gap structure significantly shortens the magnetic circuit path, effectively reducing reluctance loss (energy loss due to magnetic resistance when magnetic flux passes through a magnetic medium), thereby improving energy conversion efficiency. This makes it particularly suitable for applications sensitive to space and weight.

[0003] Compared to traditional radial flux motors (i.e., conventional motors), axial flux motors, with their unique flattened design, can achieve a smaller size and lighter weight for the same power output. Traditional radial flux motors have a flux path perpendicular to the rotation axis and a cylindrical air gap, resulting in a longer magnetic circuit and higher magnetic reluctance. Axial flux motors, on the other hand, have a larger air gap area and a shorter axial length, significantly reducing magnetic reluctance losses. Furthermore, their planar structure increases the heat dissipation area, optimizing heat dissipation performance, and the reduced rotor inertia improves dynamic response speed. However, despite these significant performance advantages, their industrialization still faces several technical bottlenecks.

[0004] (1) Problems with rotor assemblies: Existing rotor assemblies face severe challenges to mechanical stability under high-speed rotation conditions. The disc structure results in weak radial rigidity, making it prone to deformation under centrifugal force, which directly affects the uniformity of the air gap. The connection method between the rotor and the motor shaft must simultaneously meet the triple requirements of high-precision positioning, torque transmission, and dynamic balance. Traditional key connections or interference fits are difficult to guarantee long-term reliability in multi-component stacked structures. In addition, the installation accuracy of the rotor magnets is extremely high. Micrometer-level deviations can cause magnetic field imbalance, leading to torque fluctuations and electromagnetic noise problems.

[0005] (2) Problems with stator assemblies: The core contradiction of stator assemblies lies in the incompatibility between electromagnetic performance and mechanical strength. Although coreless stator structures can eliminate iron losses and improve torque response, the lack of iron core support leads to insufficient rigidity at the winding ends, making them prone to vibration and fatigue failure under electromagnetic force. While using iron core stators can enhance structural strength, it introduces eddy current losses and increases weight. At the same time, the manufacturing process of planar windings is complex, and the deformation control of the end windings under electromagnetic force is difficult, affecting long-term operational reliability.

[0006] (3) Problems with Multi-Component Stacked Structures While multi-stator and multi-rotor stacked structures can significantly increase power density, they introduce more complex system-level challenges. First, the cumulative axial tolerances of multiple components lead to a geometric increase in the difficulty of controlling air gap uniformity; even micron-level assembly errors can cause uneven magnetic reluctance distribution, resulting in torque fluctuations and electromagnetic noise. Second, the electromagnetic coupling effect between components exacerbates the complexity of the magnetic field distribution, requiring precise suppression of leakage magnetic interference between adjacent stators and rotors. At the assembly level, coaxiality calibration, preload distribution, and dynamic balance adjustment of multiple components all require ultra-high precision processes, significantly increasing manufacturing costs and mass production difficulties.

[0007] These issues are intertwined, forming a technological barrier that restricts the large-scale application of axial flux motors. The mechanical stability of the rotor assembly, the electromagnetic-structural contradictions of the stator assembly, and the precision control bottlenecks of multi-component stacking together constitute the core challenges of current technological development, which urgently require breakthroughs through systematic innovation. Summary of the Invention

[0008] This invention provides a rotor assembly, a stator assembly, and an axial flux motor, overcoming the shortcomings of the prior art. It can effectively solve the problem of low power density in existing axial flux motors and further effectively solve the problem of air gap control in existing multi-stator and multi-rotor stacked structures.

[0009] One of the technical solutions of this utility model is achieved through the following measures: a rotor assembly, including a rotor support, a permanent magnet and a bushing, wherein the rotor support is fixedly installed on the outer side of the upper end of the bushing, the rotor support is in the shape of a ring, and a number of vertically penetrating mounting holes are evenly distributed along the circumference on the upper side of the rotor support, the mounting holes are in the shape of a fan ring, and a permanent magnet is provided in the mounting hole, the permanent magnet including a number of permanent magnet blocks cut into segments along the circumference.

[0010] The following are further optimizations and / or improvements to one of the above-mentioned utility model technical solutions: The outer side of the upper end of the aforementioned bushing may be provided with an outer ring groove, and the rotor bracket is fixedly installed in the outer ring groove.

[0011] The inner side of the aforementioned bushing may be provided with a spline groove.

[0012] The second technical solution of this utility model is achieved through the following measures: a stator assembly, including a stator support, windings and an iron core. The stator support includes a mounting cylinder and spacers. Several spacers are evenly distributed along the circumference on the inner side of the upper end of the mounting cylinder. A winding placement slot is formed between every two adjacent spacers. The winding placement slot is fan-shaped and has a matching winding inside. An iron core is provided inside the winding.

[0013] The following are further optimizations and / or improvements to the second utility model technical solution mentioned above: As a preferred embodiment, the stator support may further include a stop block, with a stop block provided in the middle of the inner end of each partition plate. The stop block is T-shaped, narrower on the outside and wider on the inside. The mounting cylinder, partition plate and stop block are integrally formed, with a rounded corner smooth transition between the mounting cylinder and the outer sides of the partition plate, and a rounded corner smooth transition between the stop block and the inner sides of the partition plate.

[0014] As another preferred embodiment, the stator support may further include a retaining ring. The retaining ring is provided inside the mounting cylinder, and the retaining ring and the corresponding positions of the inner end of each spacer are fixed together. The mounting cylinder, spacer and retaining ring are integrally formed. There is a rounded corner smooth transition between the mounting cylinder and the outer ends of the spacer, and there is a rounded corner smooth transition between the retaining ring and the inner ends of the spacer.

[0015] The third technical solution of this utility model is achieved through the following measures: An axial flux motor using a rotor assembly and a stator assembly includes a housing, a motor shaft, an upper bearing, a lower bearing, a rotor assembly, a stator assembly, an end sleeve, an upper rotor assembly, and a lower rotor assembly. A motor shaft with its upper and lower ends located outside the housing is installed inside the housing. An upper bearing is provided between the upper part of the motor shaft and the housing, and a lower bearing is provided between the lower part of the motor shaft and the housing. At least two stator assemblies are installed in a limited manner inside the housing, arranged sequentially from top to bottom. Between each pair of adjacent stator assemblies, a rotor assembly is provided and installed on the outside of the motor shaft via a spline connection. The rotor support is located in the mounting cylinder below the corresponding spacer plate. An end sleeve is provided on the upper side of the uppermost sleeve and installed on the outside of the motor shaft via a spline connection. An upper mounting ring groove is provided on the outer side of the upper end of the end sleeve. An upper rotor assembly located above the stator assembly is located on the outer side of the upper mounting ring groove. A lower mounting ring groove is provided on the outer side of the lower end of the lowermost sleeve. A lower rotor assembly located in the mounting cylinder below the corresponding spacer plate is located on the outer side of the lower mounting ring groove.

[0016] The following are further optimizations and / or improvements to the third utility model technical solution mentioned above: The aforementioned upper rotor assembly may include a rotor back iron, a silicon steel disk, and end permanent magnets arranged sequentially from top to bottom. Several end permanent magnets are evenly distributed along the circumference on the lower side of the silicon steel disk. The end permanent magnets are fan-shaped and include several end permanent magnet blocks that are segmented and cut along the circumference. The lower rotor assembly has the same structure as the upper rotor assembly and is arranged symmetrically from top to bottom.

[0017] The aforementioned housing may include an upper end cover, a lower end cover, an outer cylinder, an upper support ring, a lower support ring, an upper positioning ring, and a lower positioning ring. An upper end cover located outside the motor shaft is fixedly installed at the upper end of the outer cylinder, and a lower end cover located outside the motor shaft is fixedly installed at the lower end of the outer cylinder. An upper support ring is provided on the lower side of the upper end cover corresponding to the inner position of the upper end of the outer cylinder, and an upper positioning ring is provided on the lower side of the upper support ring. A lower support ring is provided on the upper side of the lower end cover corresponding to the inner position of the lower end of the outer cylinder, and a lower positioning ring is provided on the upper side of the lower support ring. At least two stator assemblies arranged sequentially from top to bottom are installed between the upper positioning ring and the lower positioning ring for limiting.

[0018] The above may also include threaded retaining rings, locking washers, and retaining rings. An upper limit ring is provided on the lower side of the upper end cover, and an upper mounting groove is provided on the inner side of the upper limit ring. The upper bearing is located in the upper mounting groove. A positioning ring is provided on the outer side of the motor shaft corresponding to the lower position of the upper bearing. The lower side of the positioning ring abuts against the upper rotor assembly. A lower limit ring is provided on the upper side of the lower end cover, and a lower mounting groove is provided on the inner side of the lower limit ring. The lower bearing is located in the lower mounting groove. A locking washer is provided on the outer side of the motor shaft corresponding to the position between the lower rotor assembly and the lower bearing. A threaded retaining ring is provided on the lower outer side of the locking washer and is fixedly installed together with the outer side of the motor shaft. A retaining ring is provided between the lower side of the threaded retaining ring and the lower bearing.

[0019] This utility model has a reasonable and compact structure and is easy to use. By setting multiple stator assemblies and multiple rotor assemblies and adopting a stacked structure, the power density is improved. By setting an upper support ring, a lower support ring, an upper positioning ring, and a lower positioning ring, in conjunction with an upper end cover and a lower end cover, multiple stator assemblies are arranged sequentially from top to bottom inside the outer cylinder, realizing the positioning between the stator assemblies and the housing. By using a threaded retaining ring, a locking washer, and a retaining ring in conjunction with a positioning ring platform set on the outside of the motor shaft, multiple rotor assemblies, end bushings, upper rotor assemblies, and lower rotor assemblies are installed on the outside of the motor shaft, realizing the positioning between the rotor assemblies and the motor shaft. By determining the relative positions of multiple stator assemblies in the housing, and determining the relative positions of the upper rotor assembly, rotor assembly, and lower rotor assembly on the outside of the motor shaft, the air gap between the stator assemblies and rotor assemblies is controlled, which has the characteristics of stability, high efficiency, and high power density. Attached Figure Description

[0020] Appendix Figure 1 The diagram shows a top view of the structure of Examples 1 to 3.

[0021] Appendix Figure 2 For the appendix Figure 1 A three-dimensional structural diagram of the rotor support.

[0022] Appendix Figure 3 The diagram shows the top view of embodiments 4 and 5.

[0023] Appendix Figure 4 For the appendix Figure 3 A schematic diagram of the three-dimensional structure.

[0024] Appendix Figure 5 For the appendix Figure 3 A three-dimensional structural diagram of the middle stator support.

[0025] Appendix Figure 6 This is a top view of the structure of Example 6.

[0026] Appendix Figure 7 These are schematic diagrams of the front sectional view of Examples 7 to 10.

[0027] Appendix Figure 8 For the appendix Figure 7 A schematic diagram of the three-dimensional structure.

[0028] Appendix Figure 9 For the appendix Figure 7 A three-dimensional structural diagram of the rotor support.

[0029] Appendix Figure 10 For the appendix Figure 7 A three-dimensional structural diagram of the upper and middle rotor assembly.

[0030] Appendix Figure 11 For the appendix Figure 7 A three-dimensional structural diagram of the middle stator support.

[0031] The codes in the attached diagram are as follows: 1 for rotor support, 2 for permanent magnet, 3 for bushing, 4 for mounting hole, 5 for outer ring groove, 7 for spline groove, 8 for winding, 9 for iron core, 10 for mounting cylinder, 11 for spacer plate, 12 for winding placement slot, 13 for stop block, 14 for retaining ring, 15 for rotor housing cavity, 16 for motor shaft, 17 for upper bearing, 18 for lower bearing, 19 for end bushing, 20 for upper mounting ring groove, 21 for lower mounting ring groove, 2 2 is the rotor back iron, 23 is the silicon steel disc, 24 is the end permanent magnet, 25 is the lower rotor assembly, 26 is the upper end cover, 27 is the lower end cover, 28 is the outer cylinder, 29 is the upper support ring, 30 is the lower support ring, 31 is the upper positioning ring, 32 is the lower positioning ring, 33 is the threaded retaining ring, 34 is the stop washer, 35 is the retaining ring, 36 is the upper limit ring platform, 37 is the upper mounting groove, 38 is the positioning ring platform, 39 is the lower limit ring platform, and 40 is the lower mounting groove. Detailed Implementation

[0032] This utility model is not limited to the following embodiments, and the specific implementation method can be determined according to the technical solution of this utility model and the actual situation.

[0033] In this utility model, for ease of description, the description of the relative positions of the components is based on the appendix to the specification. Figure 1 The layout is described using a diagrammatic method, such as front, back, top, bottom, left, right, etc. The positional relationships are determined based on the layout direction of the attached diagram in the instruction manual.

[0034] The present invention will be further described below with reference to the embodiments and accompanying drawings: Example 1: As shown in the attached document Figure 1 , 2 As shown, the rotor assembly includes a rotor support 1, a permanent magnet 2, and a bushing 3. The rotor support 1 is fixedly mounted on the outer side of the upper end of the bushing 3. The rotor support 1 is annular in shape, and several through mounting holes 4 are evenly distributed along the circumference of the upper side of the rotor support 1. The mounting holes 4 are fan-shaped and contain permanent magnets 2. The permanent magnets 2 include several permanent magnet blocks that are cut into segments along the circumference. In use, the rotor support 1 facilitates the installation of the permanent magnets 2; the bushing 3 facilitates the overall installation of the rotor support 1 on the outside of the motor shaft 16, thereby achieving rapid assembly. In addition, the permanent magnets 2 will generate eddy currents in the alternating magnetic field, resulting in energy loss and temperature rise. By cutting the permanent magnets 2 into multiple permanent magnet blocks in the circumference, the entire magnet is divided into multiple insulated fan-shaped blocks, which can significantly shorten the eddy current loop path and reduce the eddy current effect. The segmented permanent magnets 2 can flexibly control the harmonic content of the rotor magnetic field by adjusting the size, angle, or magnetization direction of the fan-shaped blocks, reducing torque pulsation and improving the smoothness of motor operation. Depending on the requirements, permanent magnet 2 uses diamond wire cutting or laser precision cutting technology to divide sintered NdFeB and other hard and brittle permanent magnet materials into fan-shaped blocks along the circumference. The cutting accuracy needs to be controlled at the micron level to ensure that the gaps between the magnets are uniform and insulated. The permanent magnet blocks after segmentation are filled with epoxy resin or ceramic coating to form a physical insulation layer to block the eddy current path. At the same time, the isolation layer needs to have high mechanical strength to resist the centrifugal force during high-speed rotation.

[0035] The rotor assembly described above can be further optimized and / or improved according to actual needs: Example 2: As shown in the attached document Figure 1 , 2 As shown, the upper outer side of the bushing 3 is provided with an outer annular groove 5, and the rotor bracket 1 is fixedly installed in the outer annular groove 5. During use, this design allows for modular configuration of the rotor assembly. Modular rotor assemblies support standardized production, reducing customization costs and significantly decreasing maintenance costs. Furthermore, from an assembly perspective, the modular design facilitates overall installation on the outside of the motor shaft 16 and eliminates the risk of breakage due to uneven stress in the overall rotor, improving assembly accuracy and reliability. Depending on requirements, the inner side of the rotor bracket 1 may be provided with at least one keyway oriented vertically, and the upper outer side of the bushing 3 corresponding to the keyway position is provided with a key block located within the keyway.

[0036] Example 3: As shown in the attached document Figure 1 , 2 As shown, the inner side of the bushing 3 is provided with a spline groove 7. During use, this design facilitates the rotor assembly to be installed on the outside of the motor shaft 16 and fixed to the motor shaft 16 through the spline groove 7 provided on the inner side of the bushing 3.

[0037] Example 4: As shown in the appendix Figure 3 , 4 As shown in Figures 5 and 6, the stator assembly includes a stator support, windings 8, and a core 9. The stator support includes a mounting cylinder 10 and spacers 11. Several spacers 11 are evenly distributed along the circumference of the inner side of the upper end of the mounting cylinder 10. A winding placement slot 12 is formed between every two adjacent spacers 11. The winding placement slot 12 is fan-shaped and contains a matching winding 8. The core 9 is housed within the winding 8. During use, the stator support serves as the core load-bearing structure in the axial flux motor, achieving efficient integration of multiple windings 8 and cores 9 through rigid support and precise positioning. It provides uniform mechanical support for the stacked core 9, preventing interlayer loosening and deformation caused by electromagnetic forces or vibrations, thereby suppressing eddy current losses and ensuring magnetic circuit stability. Meanwhile, the stator support is equipped with precision positioning grooves or reference surfaces to ensure that multiple sets of iron cores 9 and windings 8 are strictly coaxial, maintain air gap uniformity, and avoid torque pulsation or efficiency reduction caused by eccentricity. In addition, multiple sets of windings 8 and iron cores 9 are installed in the stator support, and a potting compound process is used after assembly, which can significantly improve the overall performance and reliability of the motor. The potting compound fills the gap between windings 8 and iron cores 9 to form a dense insulating protective layer, effectively preventing short circuit risks caused by moisture and contaminant intrusion, and greatly enhancing the electrical insulation performance of multiple sets of windings 8. At the same time, the high thermal conductivity of the compound can quickly conduct the heat generated by the operation of windings 8 to the stator support and cooling system, avoid local overheating, ensure the magnetic circuit stability of iron core 9, and thus improve motor efficiency and power density. On the mechanical level, the potting compound forms a rigid structure after curing, which firmly fixes multiple sets of iron cores 9 and windings 8 in the stator support, suppresses the loosening of windings 8 or displacement of iron cores 9 caused by electromagnetic vibration, reduces mechanical wear and noise, and extends motor life.

[0038] The above stator components can be further optimized and / or improved according to actual needs: Example 5: As shown in the attached document Figure 3 , 4As shown in Figure 5, the stator support also includes a stop block 13. Each spacer plate 11 has a stop block 13 at its inner center, and the stop block 13 is T-shaped, narrower on the outside and wider on the inside. The mounting cylinder 10, spacer plate 11, and stop block 13 are integrally formed. The mounting cylinder 10 and the outer sides of the spacer plate 11 have a rounded corner smooth transition, and the stop block 13 and the inner sides of the spacer plate 11 also have a rounded corner smooth transition. During use, the assembly groove formed by the stator support adopts a rounded corner smooth transition design, mainly to optimize mechanical performance, electromagnetic characteristics, and assembly processability. On the mechanical level, the smooth transition of rounded corners effectively eliminates stress concentration at the sharp corners of the slot, significantly improving the structural strength of the iron core 9 during installation and avoiding the risk of slot cracking due to vibration or impact, thereby extending the service life of the stator support. Electromagnetically, the arc-shaped slot smooths the magnetic field distribution path, reduces eddy current losses caused by sudden changes in magnetic reluctance, reduces energy loss of the iron core 9 under alternating magnetic fields, and improves motor efficiency. In addition, the smooth transition of the slot wall design facilitates the embedding and positioning of the winding 8 coil, reduces insulation layer scratch damage, and improves the yield rate of automated assembly. According to requirements, the mounting cylinder 10, the spacer plate 11, and the stop block 13 are integrated. The three materials can be aluminum alloy. The setting of the stop block 13 can prevent magnetic circuit closure. The main purpose of using aluminum alloy is to significantly reduce the overall weight of the motor through its lightweight characteristics, while using the high strength and rigidity of aluminum alloy to ensure structural stability, effectively supporting the stator assembly and withstanding electromagnetic forces and mechanical stresses during operation. In addition, aluminum's excellent corrosion resistance can extend the service life of the bracket in complex environments and reduce maintenance needs; its good plasticity allows for the customization of different structural forms according to design requirements, optimizing spatial layout and improving assembly flexibility.

[0039] Example 6: As shown in the appendix Figure 6As shown, the stator support also includes a retaining ring 14. The retaining ring 14 is installed inside the mounting cylinder 10, and is fixedly installed together with the corresponding positions at the inner center of each spacer plate 11. The mounting cylinder 10, spacer plate 11, and retaining ring 14 are integrally formed. A rounded corner smooth transition is provided between the outer ends of the mounting cylinder 10 and the spacer plate 11, and a rounded corner smooth transition is provided between the retaining ring 14 and the inner ends of the spacer plate 11. During use, the assembly groove formed by the stator support adopts a rounded corner smooth transition design, mainly to optimize mechanical performance, electromagnetic characteristics, and assembly processability. On the mechanical level, the smooth transition of rounded corners effectively eliminates stress concentration at the sharp corners of the slot, significantly improving the structural strength of the iron core 9 during installation and avoiding the risk of slot cracking due to vibration or impact, thereby extending the service life of the stator support. Electromagnetically, the arc-shaped slot smooths the magnetic field distribution path, reduces eddy current losses caused by sudden changes in magnetic reluctance, reduces energy loss of the iron core 9 under alternating magnetic fields, and improves motor efficiency. In addition, the slot wall design with smooth rounded corner transitions is more conducive to the embedding and positioning of the winding 8 coil, reducing insulation layer scratch damage and improving the yield rate of automated assembly. According to requirements, the mounting cylinder 10, spacer plate 11, and retaining ring 14 are integrated. The three materials can be engineering plastics. Their main function is to effectively block current conduction using their excellent insulation properties, preventing short circuits or leakage risks during motor operation, while significantly reducing the weight of the support, achieving a lightweight motor design, and improving energy efficiency and portability. In addition, engineering plastics have excellent chemical corrosion resistance and high temperature resistance, which can adapt to complex working conditions such as humidity, acid and alkali, extend the life of the support and reduce maintenance needs; their good mechanical strength and rigidity can stably support the iron core 9 and winding 8, ensuring that the electromagnetic coil maintains accurate position and structural integrity during high-speed operation.

[0040] Example 7: As attached Figures 1 to 11As shown, the axial flux motor using the aforementioned rotor and stator assemblies includes a housing, a motor shaft 16, an upper bearing 17, a lower bearing 18, a rotor assembly, a stator assembly, an end bushing 19, an upper rotor assembly, and a lower rotor assembly 25. The motor shaft 16, with its upper and lower ends located outside the housing, is installed inside the housing. An upper bearing 17 is provided between the upper part of the motor shaft 16 and the housing, and a lower bearing 18 is provided between the lower part of the motor shaft 16 and the housing. At least two stator assemblies are installed within the housing, arranged sequentially from top to bottom. Each pair of adjacent stator assemblies is connected by a spline. The rotor assembly is mounted on the outside of the motor shaft 16. The rotor support 1 is located in the mounting cylinder 10 below the corresponding spacer plate 11. The uppermost bushing 3 is provided with an end bushing 19 connected to the outside of the motor shaft 16 via a spline. The upper outer side of the end bushing 19 is provided with an upper mounting ring groove 20. The upper rotor assembly is located above the stator assembly on the outer side of the upper mounting ring groove 20. The lower outer side of the lower end of the bushing 3 is provided with a lower mounting ring groove 21. The lower rotor assembly 25 is located in the mounting cylinder 10 below the corresponding spacer plate 11 on the outer side of the lower mounting ring groove 21. During use, the core advantage of employing multiple stator and rotor assemblies lies in the fact that the multi-disc stacked structure can significantly improve the power density and torque density of this axial flux motor. The stacking of multiple components multiplies the electromagnetic action area, allowing for higher power and torque output within the same volume. By setting upper bearings 17 and lower bearings 18 at both ends of the motor shaft 16, a rigid support system is formed, accommodating both radial and axial loads and effectively preventing axial movement of the rotor assembly, stator assembly, end bushings 19, upper rotor assembly, and lower rotor assembly 25. The inner sides of the bushings 3 and end bushings 19 are provided with spline grooves 7, which engage with the splines on the outer side of the motor shaft 16 using an interference fit to achieve torque transmission and axial positioning, ensuring coaxiality and reducing vibration.

[0041] The above-mentioned axial flux motor can be further optimized and / or improved according to actual needs: Example 8: As attached Figures 1 to 11As shown, the upper rotor assembly includes a rotor back iron 22, a silicon steel disk 23, and end permanent magnets 24 arranged sequentially from top to bottom. Several end permanent magnets 24 are evenly distributed along the circumference of the lower side of the silicon steel disk 23. Each end permanent magnet 24 is fan-shaped and includes several end permanent magnet blocks cut into segments along the circumference. The lower rotor assembly 25 has the same structure as the upper rotor assembly and is arranged symmetrically. During use, the upper rotor assembly and lower rotor assembly 25, formed by the rotor back iron 22, silicon steel disk 23, and end permanent magnets 24, play a crucial role in constructing an efficient magnetic circuit and optimizing electromagnetic performance. Specifically, the permanent magnets 2 (such as neodymium iron boron) provide a stable magnetic field; the silicon steel disk 23 effectively conducts magnetic flux due to its high permeability, enhancing the magnetic field strength, and its low iron loss characteristics reduce eddy current losses; the rotor back iron 22, as a key component for magnetic circuit closure, further optimizes the magnetic flux path, reduces leakage flux, and enhances the magnetic field strength, ensuring the efficient conversion of electromagnetic energy into mechanical energy.

[0042] Example 9: As attached Figures 1 to 11 As shown, the housing includes an upper end cover 26, a lower end cover 27, an outer cylinder 28, an upper support ring 29, a lower support ring 30, an upper positioning ring 31, and a lower positioning ring 32. The upper end cover 26 located outside the motor shaft 16 is fixedly installed on the upper end of the outer cylinder 28, and the lower end cover 27 located outside the motor shaft 16 is fixedly installed on the lower end of the outer cylinder 28. The upper support ring 29 is provided on the lower side of the upper end cover 26 corresponding to the inner position of the upper end of the outer cylinder 28, and the upper positioning ring 31 is provided on the lower side of the upper support ring 29. The lower support ring 30 is provided on the upper side of the lower end cover 27 corresponding to the inner position of the lower end of the outer cylinder 28, and the lower positioning ring 32 is provided on the upper side of the lower support ring 30. At least two stator assemblies arranged sequentially from top to bottom are installed between the upper positioning ring 31 and the lower positioning ring 32 for limiting. During use, by setting up upper support ring 29, lower support ring 30, upper positioning ring 31, and lower positioning ring 32, along with upper end cover 26 and lower end cover 27, multiple stator assemblies are sequentially arranged from top to bottom within the outer cylinder 28. High-precision coaxial alignment optimizes electromagnetic performance and enhances mechanical stability. Axial positioning ensures uniform air gap between each stator assembly and rotor assembly (typically controlled within a tolerance of 0.1 to 0.3 mm), eliminating magnetic reluctance imbalance caused by eccentricity, thereby significantly reducing torque fluctuations and electromagnetic noise, and improving motor smoothness. Simultaneously, precise positioning ensures the magnetic field coupling efficiency between multiple stator assemblies and rotor permanent magnets 2, minimizing the magnetic flux path, reducing leakage magnetic loss, and thus improving power density and efficiency. Mechanically, the positioning and limiting connection structure effectively suppresses axial movement and radial vibration during high-speed rotation, reducing bearing load and extending the life of the transmission system. As required, the housing is equipped with existing cooling channels, and the upper end cover 26 and lower end cover 27 are respectively provided with liquid inlet and outlet holes.

[0043] Example 10: As attached Figures 1 to 11As shown, it also includes a threaded retaining ring 33, a stop washer 34, and a retaining ring 35. The upper end cover 26 has an upper limit ring platform 36 on its lower side, and an upper mounting groove 37 is provided on the inner side of the upper limit ring platform 36. The upper bearing 17 is located in the upper mounting groove 37. A positioning ring platform 38 is provided on the outer side of the motor shaft 16 corresponding to the lower position of the upper bearing 17. The lower side of the positioning ring platform 38 abuts against the upper rotor assembly. The lower end cover 27 has a lower limit ring platform 39 on its upper side, and a lower mounting groove 40 is provided on the inner side of the lower limit ring platform 39. The lower bearing 18 is located in the lower mounting groove 40. A stop washer 34 is provided on the outer side of the motor shaft 16 corresponding to the position between the lower rotor assembly 25 and the lower bearing 18. A threaded retaining ring 33 is provided on the lower outer side of the stop washer 34 and is fixedly installed together with the outer side of the motor shaft 16. A retaining ring 35 is provided between the lower side of the threaded retaining ring 33 and the lower bearing 18. During use, the threaded retaining ring 33, the locking washer 34, and the retaining ring 35 cooperate with the positioning ring 38 on the outside of the motor shaft 16 to install multiple rotor assemblies, end bushings 19, upper rotor assembly, and lower rotor assembly 25 on the outside of the motor shaft 16. Simultaneously, the spline grooves 7 on the inner sides of the bushings 3 and 19 engage with the splines on the outside of the motor shaft 16 using an interference fit. The core function of this multi-fixed structure is to achieve high-precision positioning, efficient torque transmission, and long-term operational stability. Specifically, the threaded retaining ring 33 provides axial preload to ensure that the rotor assembly does not move axially. The locking washer 34 mechanically locks the threaded retaining ring 33 to prevent it from loosening under vibration conditions, providing double assurance for the reliability of axial positioning. The spline groove 7 and spline meshing design achieve precise torque transmission, avoiding deformation or failure of the key connection due to shear force, which is especially suitable for high-power output scenarios of high torque density axial flux motors. The interference fit forms a rigid connection with the motor shaft 16 through the radial interference of the inner hole of the bushing 3 and the end bushing 19, eliminating the fit clearance, suppressing fretting wear during high-speed rotation, and improving the coaxiality and dynamic balance accuracy of the rotor system, significantly reducing electromagnetic noise and vibration. Therefore, this composite structure adopted by the rotor assembly and the motor shaft 16, through the triple synergy of axial limiting, circumferential torque transmission and radial fastening, not only solves the positioning problem of multi-rotor assemblies under complex working conditions, but also greatly improves the mechanical strength and life of the motor under high-speed and high-load environments, becoming a key design to ensure the power performance of the axial flux motor.

[0044] Example 11: As shown in the appendix Figure 7 As shown, in conjunction with the content of Embodiments 9 to 10, this invention addresses how to solve the core difficulty of air gap control in existing manufacturing processes when increasing the power density by increasing the electromagnetic interaction area in the multi-component stacked structure adopted by this invention.

[0045] The air gap is a non-contact air layer between the stator and rotor, typically on the order of millimeters (0.5 to 2 mm is common in axial flux motors). As the necessary path for magnetic lines of force to travel from the stator windings to the rotor magnets, it directly determines the magnitude of the magnetic reluctance in the magnetic circuit. If the air gap is uniform and precisely sized, magnetic flux can be transmitted efficiently, ensuring stable electromagnetic torque output; conversely, air gap deviations will lead to uneven magnetic reluctance distribution, causing magnetic field distortion, reducing motor efficiency, and increasing torque ripple.

[0046] The problem of "uneven air gaps" is particularly prominent in multi-component stacked structures: (1) Magnetic reluctance change and torque fluctuation: When the stator and rotor are not strictly coaxial due to assembly error, the air gap thickness varies in the circumferential direction (e.g., 0.8mm on one side and 1.2mm on the other side). The magnetic reluctance is proportional to the air gap thickness. The magnetic flux is dense in the gap and sparse in the gap, which leads to an increase in the pulsation of the combined torque and affects the smoothness of motor operation. (2) Risk of mechanical friction: If the air gap is too small locally (such as due to rotor sway or thermal deformation), the stator and rotor may scrape each other during high-speed rotation, causing permanent damage. For example, micron-level deviation (>10μm) in the installation of magnets may cause local contact. (3) NVH performance deterioration: The magnetic field imbalance caused by uneven air gap will generate radial electromagnetic force, which will excite vibration and noise. In axial flux motors, the multi-disc structure will amplify this effect, resulting in high-frequency howling or low-frequency resonance.

[0047] In existing technologies, axial flux motors employing three or more stator and rotor assemblies require higher air gap accuracy. (1) Accumulated error amplification: The coaxiality deviation of each layer of stator and rotor will be superimposed along the axial direction, and the air gap uniformity of the end component may far exceed the design tolerance (such as ±0.05mm), which requires high-precision tooling (such as laser alignment instrument) and automated assembly equipment control. (2) Phase matching requirement: The electromagnetic phase of each layer of stator winding 8 and rotor magnetic pole must be strictly aligned. If the air gap deviation causes phase misalignment, the magnetic fields between layers will interfere with each other, further deteriorating the torque output stability.

[0048] In summary, the air gap is a core issue in the design of axial flux motors, and its uniformity directly affects efficiency, reliability, and NVH performance. While multi-component stacking structures increase power density by expanding the electromagnetic interaction area, they also impose micron-level precision requirements on air gap control, making it a key challenge in the manufacturing process.

[0049] In the specific design and implementation process of this utility model, (1) Solving the positioning between the stator and the housing: By setting the upper support ring 29, the lower support ring 30, the upper positioning ring 31 and the lower positioning ring 32, and cooperating with the upper end cover 26 and the lower end cover 27, multiple stator components are arranged in the outer cylinder 28 from top to bottom (Example 9). (2) Solving the positioning between the rotor and the motor shaft 16: By using the threaded retaining ring 33, the stop washer 34 and the retaining ring 35 to cooperate with the positioning ring platform 38 set on the outside of the motor shaft 16, multiple rotor assemblies, end bushings 19, upper rotor assembly and lower rotor assembly 25 are installed on the outside of the motor shaft 16 (Example 10). Specifically, an outer ring groove 5 is provided on the outer side of the upper end of the bushing 3, so that the rotor bracket 1 is fixedly installed in the outer ring groove 5. The upper side of the bushing 3 at the uppermost position is provided with an end bushing 19 installed on the outside of the motor shaft 16. The upper side of the end bushing 19 is provided with an upper mounting ring groove 20. The upper rotor assembly is located above the stator assembly on the outer side of the upper mounting ring groove 20. The lower side of the bushing 3 at the lowermost position is provided with a lower mounting ring groove 21. The lower rotor assembly 25 is located in the mounting cylinder 10 below the corresponding spacer plate 11 on the outer side of the lower mounting ring groove 21. (3) Solving the air gap control between the stator assembly and the rotor assembly: After solving (1) and (2), the relative positions of multiple stator assemblies in the housing, and the relative positions of the upper rotor assembly, rotor assembly and lower rotor assembly 25 on the outside of the motor shaft 16 have been determined. At this time, the rotor bracket 1 is located in the mounting cylinder 10 below the corresponding spacer plate 11 (i.e., the lower interior of the stator assembly), making the lower interior of the stator assembly the rotor receiving cavity 15, as shown in the attached figure. Figure 11 As shown.

[0050] The multi-component stacked structure adopted in the preferred embodiment of this utility model systematically solves three core problems: the positioning between the rotor assembly and the motor shaft 16, the positioning between the stator assembly and the housing, and the air gap control between the stator assembly and the rotor assembly. This structure can form a synergistic effect and fundamentally improve the overall performance and reliability of the motor.

[0051] Solving the positioning problem between the rotor assembly and the motor shaft 16 ensures the accuracy and stability of power transmission. As the direct output end of the electromagnetic torque, the rigid connection between the rotor assembly and the motor shaft 16 eliminates the possibility of relative displacement, making the torque transmission path energy-free. This high-precision positioning avoids axial movement or radial runout of the rotor during high-speed rotation or sudden load changes, fundamentally suppressing mechanical vibration sources. Simultaneously, the stable rotor shaft system provides a benchmark guarantee for the uniformity of the subsequent stator-rotor air gap, ensuring that the output of the electromagnetic torque remains controllable, laying a solid foundation for the motor's dynamic response under complex operating conditions.

[0052] Precise positioning between the stator assembly and the motor housing creates a stable electromagnetic field environment. As the source of the magnetic field, the stability of the stator's position in space is directly determined by the precision of its fixation to the housing. When the stator assembly is strictly constrained to its preset position within the housing, the magnetic field distribution generated by the windings 8 closely matches the design model, preventing magnetic field distortion caused by housing deformation or loose assembly. This stability not only ensures the synchronization of the electromagnetic phase between the various layers of stator windings 8 but also prevents interference from external mechanical vibrations on the magnetic field environment. The stable stator housing system acts as an "electromagnetic anchor," ensuring that the magnetic field coupling in the multi-component stacked structure remains optimal, creating a prerequisite for efficient energy conversion.

[0053] Precise control of the air gap between the stator and rotor assemblies is a core aspect of electromagnetic performance optimization. As the essential channel for magnetic field lines, the uniformity of the air gap directly determines the symmetry of the magnetic reluctance distribution. When the air gap thickness remains highly consistent circumferentially, there are no localized blockages or sparsity in the magnetic flux path, allowing magnetic field energy to be transferred seamlessly from the stator to the rotor. This uniformity eliminates torque pulsations caused by air gap deviations, resulting in smooth and stable motor output torque and significantly reduced electromagnetic noise and vibration. Simultaneously, precise air gap control avoids the risk of mechanical contact between the stator and rotor, ensuring safety during high-speed operation. In multi-component stacked structures, the coordinated consistency of interlayer air gaps further amplifies this effect, enabling the entire electromagnetic system to form a highly efficient and low-loss energy conversion network.

[0054] The coordinated solution to the three major positioning problems ultimately led to a leap in the overall performance of the multi-component stacked structure. Rotor-shaft positioning ensured rigid power transmission, stator-casing positioning created a stable magnetic field environment, and stator-rotor air gap control guaranteed high efficiency in electromagnetic conversion. Together, these three elements enabled the motor to achieve levels of power density, torque response, operational smoothness, and lifespan reliability that are difficult to attain with traditional structures. This systematic positioning optimization not only solved the inherent technical bottlenecks of multi-component stacking but also provided a reliable technical path for advanced motor systems with high power density and high integration through precise structural coordination.

[0055] The above technical features constitute the embodiments of this utility model, which have strong adaptability and implementation effect. Unnecessary technical features can be added or removed according to actual needs to meet the needs of different situations.

Claims

1. A rotor assembly, characterized in that... It includes a rotor support, a permanent magnet, and a bushing. The rotor support is fixedly installed on the outer side of the upper end of the bushing. The rotor support is circular. Several through mounting holes are evenly distributed along the circumference on the upper side of the rotor support. The mounting holes are fan-shaped and contain permanent magnets. The permanent magnets include several permanent magnet blocks that are cut into segments along the circumference.

2. The rotor assembly according to claim 1, characterized in that... The upper outer side of the bushing is provided with an outer ring groove, and the rotor bracket is fixedly installed in the outer ring groove.

3. The rotor assembly according to claim 1 or 2, characterized in that... The inner side of the bushing is provided with a spline groove.

4. A stator assembly, characterized in that... It includes a stator support, windings and iron core. The stator support includes a mounting cylinder and spacers. Several spacers are evenly distributed along the circumference on the inner side of the upper end of the mounting cylinder. A winding placement slot is formed between every two adjacent spacers. The winding placement slot is fan-shaped and contains a matching winding. The winding contains an iron core.

5. The stator assembly according to claim 4, characterized in that... The stator support also includes a stop block. Each partition plate has a stop block in the middle of its inner end. The stop block is T-shaped, narrower on the outside and wider on the inside. The mounting cylinder, partition plate and stop block are integrated. There is a rounded corner smooth transition between the mounting cylinder and the outer sides of the partition plate. There is also a rounded corner smooth transition between the stop block and the inner sides of the partition plate.

6. The stator assembly according to claim 4, characterized in that... The stator support also includes a retaining ring. The retaining ring is installed inside the mounting cylinder. The retaining ring and the corresponding position of the inner end of each partition plate are fixed together. The mounting cylinder, partition plate and retaining ring are integrated. There is a rounded corner smooth transition between the mounting cylinder and the outer ends of the partition plate. There is a rounded corner smooth transition between the retaining ring and the inner ends of the partition plate.

7. An axial flux motor using a rotor assembly as claimed in any one of claims 1 to 3 and a stator assembly as claimed in any one of claims 4 to 6, characterized in that... The assembly includes a housing, a motor shaft, an upper bearing, a lower bearing, a rotor assembly, a stator assembly, end bushings, an upper rotor assembly, and a lower rotor assembly. The housing houses the motor shaft, with its upper and lower ends located outside the housing. An upper bearing is positioned between the upper part of the motor shaft and the housing, and a lower bearing is positioned between the lower part of the motor shaft and the housing. At least two stator assemblies are installed within the housing, arranged sequentially from top to bottom. Between each pair of adjacent stator assemblies, a rotor assembly is connected via a spline and installed on the outside of the motor shaft. A rotor support is located within a mounting cylinder below a corresponding spacer plate. An end bushing connected via a spline is positioned on the upper side of the upper bushing, and an upper mounting ring groove is located on the outer side of the upper end of the end bushing. An upper rotor assembly located above the stator assembly is located on the outer side of the upper mounting ring groove. A lower mounting ring groove is located on the outer side of the lower end of the lower bushing, and a lower rotor assembly located within a mounting cylinder below a corresponding spacer plate is located on the outer side of the lower mounting ring groove.

8. The axial flux motor according to claim 7, characterized in that... The upper rotor assembly includes a rotor back iron, a silicon steel disk, and end permanent magnets arranged sequentially from top to bottom. Several end permanent magnets are evenly distributed along the circumference on the lower side of the silicon steel disk. The end permanent magnets are fan-shaped and include several end permanent magnet blocks that are cut into segments along the circumference. The lower rotor assembly has the same structure as the upper rotor assembly and is arranged symmetrically from top to bottom.

9. The axial flux motor according to claim 7 or 8, characterized in that... The housing includes an upper end cover, a lower end cover, an outer cylinder, an upper support ring, a lower support ring, an upper positioning ring, and a lower positioning ring. An upper end cover located outside the motor shaft is fixedly installed on the upper end of the outer cylinder, and a lower end cover located outside the motor shaft is fixedly installed on the lower end of the outer cylinder. An upper support ring is provided on the lower side of the upper end cover corresponding to the inner position of the upper end of the outer cylinder, and an upper positioning ring is provided on the lower side of the upper support ring. A lower support ring is provided on the upper side of the lower end cover corresponding to the inner position of the lower end of the outer cylinder, and a lower positioning ring is provided on the upper side of the lower support ring. At least two stator assemblies arranged sequentially from top to bottom are installed between the upper positioning ring and the lower positioning ring for limiting.

10. The axial flux motor according to claim 9, characterized in that... It also includes a threaded retaining ring, a locking washer, and a retaining ring. The upper end cover has an upper limit ring platform on its lower side, and an upper mounting groove on its inner side. The upper bearing is located in the upper mounting groove. A positioning ring platform is located on the outer side of the motor shaft corresponding to the lower side of the upper bearing. The lower side of the positioning ring platform abuts against the upper rotor assembly. The lower end cover has a lower limit ring platform on its upper side, and a lower mounting groove is located on its inner side. The lower bearing is located in the lower mounting groove. A locking washer is located on the outer side of the motor shaft corresponding to the position between the lower rotor assembly and the lower bearing. A threaded retaining ring is fixedly installed on the outer side of the lower part of the locking washer and is fixedly installed together with the outer side of the motor shaft. A retaining ring is located between the lower side of the threaded retaining ring and the lower bearing.

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