Axial flux motor and electric cylinder

Abstract

The invention relates to the technical field of axial magnetic flux motors, in particular to an axial magnetic flux motor and an electric cylinder, the axial magnetic flux motor comprises a casing, a motor shaft, an upper bearing, a lower bearing, a rotor assembly, a stator assembly, an end shaft sleeve, an upper rotor assembly and a lower rotor assembly, and the motor shaft with the upper end and the lower end located outside the casing is mounted in the casing; the device comprises a cylinder body, an axial magnetic flux motor, a speed reducer, a planetary roller screw and a piston rod, the axial magnetic flux motor, the speed reducer and the planetary roller screw are arranged in the cylinder body, and the piston rod capable of extending outwards is arranged in the cylinder body. According to the invention, the structure is reasonable and compact, the use is convenient, the immersed liquid cooling design is adopted, the cooling liquid circularly flows from bottom to top and is in direct contact with stator and rotor core components to realize efficient uniform-temperature heat dissipation, the hot-spot temperature is obviously reduced, and local overheating is prevented; by arranging the plurality of stator assemblies and the plurality of rotor assemblies and adopting a stacked structure, the power density is improved, and the motor has the characteristics of stability, good heat dissipation and large power density.

Description

Technical Field

[0001] This invention relates to the field of axial flux motor technology, specifically an axial flux motor and an electric cylinder. 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 and power density for the same power output, making it a crucial development direction in modern motor technology. Its planar air gap structure significantly shortens the magnetic path, effectively reducing reluctance losses and thus improving energy conversion efficiency, making it particularly suitable for space- and weight-sensitive applications.

[0003] Compared to traditional radial flux motors, axial flux motors, thanks to their flattened design, achieve 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, with their larger air gap area and shorter axial length, not only significantly reduce magnetic reluctance losses but also optimize heat dissipation by increasing the heat dissipation area through a planar structure and improving dynamic response speed by reducing rotor moment of inertia. 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 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 rotor permanent magnets are prone to irreversible demagnetization under high-temperature environments, and the heat conduction path of the planar structure is limited, which exacerbates the difficulty of thermal management.

[0005] (2) Problems with stator assemblies: The core contradiction of stator assemblies lies in the trade-off 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 forces. While using iron core stators can enhance structural strength, it introduces eddy current losses and increases weight. At the same time, the heat dissipation efficiency of planar windings is limited by axial dimensions, and traditional air-cooling solutions are difficult to meet the requirements of high power density, while integrated liquid cooling channels significantly increase structural complexity and manufacturing costs.

[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 tolerance of multiple components leads 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 heat conduction path formed by the stacked structure is tortuous, making it difficult to effectively dissipate heat from intermediate components, which can easily lead to local overheating. In addition, 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 and thermal management 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 first solves the problem of poor heat dissipation in existing multi-stator and multi-rotor stacked structures, further solves the problem of low power density in existing axial flux motors, and finally solves the problem of uncontrollable air gap in existing multi-stator and multi-rotor stacked structures.

[0009] One of the technical solutions of this invention is achieved through the following measures: An axial flux motor 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. 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. An upper rotor assembly is installed above the uppermost stator assembly, mounted on the outside of the motor shaft. A bushing is provided between each pair of adjacent upper and lower stator assemblies. The rotor assembly is mounted on the outside of the motor shaft. Below the stator assembly at the bottom position, there is a lower rotor assembly mounted on the outside of the motor shaft. The upper rotor assembly, rotor assembly, and lower rotor assembly are sequentially positioned and mounted on the outside of the motor shaft from top to bottom. At least one coolant inlet hole is provided at circumferential intervals on the lower outer part of the housing below the lower rotor assembly. At least one coolant outlet hole is provided at circumferential intervals on the upper outer part of the housing above the upper rotor assembly. Several vertically penetrating cooling grooves are provided on the outside of the stator assembly. Several vertically penetrating cooling holes are provided on the rotor assembly, upper rotor assembly, and lower rotor assembly.

[0010] The following are further optimizations and / or improvements to one of the above-mentioned technical solutions: The stator assembly mentioned above may include 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 of 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. An iron core is placed inside the winding. Several vertically penetrating cooling grooves are evenly distributed along the circumference of the outer side of the mounting cylinder. A through hole is provided in the cooling groove corresponding to the lower position of the spacer.

[0011] As a preferred embodiment, the stator support may further include 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 integrally formed. The mounting cylinder and the two sides of the outer end of the partition plate are provided with rounded corners for a smooth transition. The stop block and the two sides of the inner end of the partition plate are also provided with rounded corners for a smooth transition.

[0012] As another preferred embodiment, the stator support may also include a retaining ring. The retaining ring is provided inside the mounting cylinder. 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. The mounting cylinder and the outer ends of the spacer are provided with rounded corners for a smooth transition. The retaining ring and the inner ends of the spacer are provided with rounded corners for a smooth transition.

[0013] The aforementioned rotor assembly may include a rotor support, permanent magnets, and a bushing. The upper outer side of the bushing is provided with an outer annular groove, and the rotor support is fixedly installed in the outer annular groove. The rotor support is circular, and a number of vertically penetrating mounting holes are evenly distributed along the circumference of the upper side of the rotor support. The mounting holes are fan-shaped and contain permanent magnets. The upper rotor assembly includes a rotor back iron, a silicon steel disk, and end permanent magnets arranged sequentially from top to bottom. A number of end permanent magnets are evenly distributed along the circumference of the lower side of the silicon steel disk. The end permanent magnets are fan-shaped. The rotor support and the rotor back iron are both provided with a number of cooling holes at intervals along the circumference. The lower rotor assembly has the same structure as the upper rotor assembly and is arranged symmetrically from top to bottom.

[0014] The above may also include end bushings, with spline grooves on the inner side of the end bushings and the bushings. Between each pair of adjacent stator assemblies, there is a rotor assembly 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. The upper side of the bushing at the uppermost position is provided with an end bushing installed on the outside of the motor shaft via a spline connection. The upper outer side of the end bushing is provided with an upper mounting ring groove. The upper rotor assembly located above the stator assembly is located on the outer side of the upper mounting ring groove. The lower outer side of the bushing at the lowermost position is provided with a lower mounting ring groove. The 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.

[0015] Both the aforementioned end permanent magnet blocks and permanent magnets can include several permanent magnet blocks that are cut into segments along the circumferential direction.

[0016] 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.

[0017] 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.

[0018] The second technical solution of the present invention is achieved through the following measures: an electric cylinder using an axial flux motor, comprising a cylinder body, an axial flux motor, a reducer, a planetary roller screw, and a piston rod. The cylinder body is provided with the axial flux motor, the reducer, and the planetary roller screw, and the cylinder body is provided with a piston rod that can extend outward. The motor shaft of the axial flux motor is drivenly connected to the input end of the reducer, the output end of the reducer is drivenly connected to the nut end of the planetary roller screw, and the screw end of the planetary roller screw is drivenly connected to the piston rod.

[0019] This invention features a rational and compact structure, and is easy to use. By employing an immersion liquid cooling design, the coolant circulates from bottom to top, directly contacting the core stator and rotor components to achieve efficient and uniform heat dissipation, significantly reducing hot spot temperatures and preventing localized overheating. Multiple stator and rotor assemblies are arranged in a stacked structure to increase power density. Upper and lower support rings, upper and lower positioning rings, along with upper and lower end covers, sequentially position the stator assemblies within the outer cylinder from top to bottom, achieving proper positioning between the stator assemblies and the housing. Threaded retaining rings, locking washers, and retaining rings, in conjunction with a positioning ring platform on the outside of the motor shaft, install multiple rotor assemblies, end sleeves, upper rotor assemblies, and lower rotor assemblies on the outside of the motor shaft, achieving proper positioning between the rotor assemblies and the motor shaft. By determining the relative positions of the multiple stator assemblies within the housing, and the relative positions of the upper, rotor, and lower rotor assemblies on the outside of the motor shaft, air gap control between the stator and rotor assemblies is achieved, resulting in stability, excellent heat dissipation, and high power density. Attached Figure Description

[0020] Appendix Figure 1 These are schematic diagrams of the front sectional view of Examples 1 to 10.

[0021] Appendix Figure 2 For the appendix Figure 1 A schematic diagram of the three-dimensional structure.

[0022] Appendix Figure 3 For the appendix Figure 1 A top view of the middle stator assembly.

[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 1 A top view of the rotor assembly.

[0025] Appendix Figure 6 For the appendix Figure 5 A three-dimensional structural diagram of the rotor support.

[0026] Appendix Figure 7 For the appendix Figure 1 A three-dimensional structural diagram of the upper and middle rotor assembly.

[0027] Appendix Figure 8 For the appendix Figure 1 A three-dimensional structural diagram of the rotor support.

[0028] Appendix Figure 9 This is a three-dimensional structural diagram of the stator support in Example 3.

[0029] Appendix Figure 10This is a top view of the stator assembly in Example 4.

[0030] Appendix Figure 11 This is a schematic diagram of the front sectional view of Example 12.

[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, 22 for rotor back iron, 23 for silicon steel disc, 24 for end permanent magnet, 25 for lower rotor assembly, 26 for... 27 is the upper end cover, 28 is the lower end cover, 29 is the outer cylinder, 30 is the upper support ring, 31 is the lower support ring, 32 is the upper positioning ring, 33 is the lower positioning ring, 34 is the threaded retaining ring, 35 is the stop washer, 36 is the retaining ring, 37 is the upper upper mounting groove, 38 is the positioning ring, 39 is the lower limit ring, 40 is the lower mounting groove, 41 is the coolant inlet, 42 is the coolant outlet, 43 is the cooling groove, 44 is the cooling hole, 45 is the through hole, 46 is the cylinder block, 47 is the reducer, 48 is the piston rod, and 49 is the brake device. Detailed Implementation

[0032] The present invention is not limited to the following embodiments, and the specific implementation can be determined according to the technical solution of the present invention and the actual situation.

[0033] In this invention, 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 embodiments and accompanying drawings: Example 1: As shown in the attached document Figures 1 to 10As shown, the axial flux motor 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 inside the housing in a top-to-bottom arrangement. Above the uppermost stator assembly, an upper rotor assembly is installed on the outside of the motor shaft 16. Between every two adjacent upper and lower stator assemblies, an end bushing 19 is installed on the outside of the motor shaft 16. The rotor assembly includes a lower rotor assembly 25 mounted on the outside of the motor shaft 16 below the stator assembly at the lowest position. The upper rotor assembly, rotor assembly, and lower rotor assembly 25 are sequentially positioned and mounted on the outside of the motor shaft 16 from top to bottom. At least one coolant inlet hole 41 is provided at circumferential intervals on the lower outer side of the housing below the lower rotor assembly 25, and at least one coolant outlet hole 42 is provided at circumferential intervals on the upper outer side of the housing above the upper rotor assembly. Several vertically penetrating cooling grooves 43 are provided on the outside of the stator assembly, and several vertically penetrating cooling holes 44 are provided on the rotor assembly, upper rotor assembly, and lower rotor assembly 25.

[0035] 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 the axial flux motor. The stacking of multiple components multiplies the electromagnetic interaction 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. Furthermore, the coolant enters through the coolant inlet 41 at the bottom of the housing and flows out through the coolant outlet 42 at the top, with the rotor and stator assemblies completely immersed in the coolant. This design primarily achieves efficient heat dissipation through direct contact liquid cooling, with significant effects. The coolant forms a circulating convection path inside the housing, and the low-temperature liquid entering from the bottom fully wets the stator windings 8 and rotor magnets, directly absorbing the heat generated. Through its high specific heat capacity and fluidity, it quickly carries away the heat energy and flows out from the high-temperature area at the top, significantly shortening the heat conduction path and avoiding the need for traditional indirect cooling (such as water jackets). Overcoming the thermal resistance bottleneck, the immersion cooling method employed in this invention significantly reduces the hot spot temperature of the motor (especially for high power density motors), effectively improving the uniformity of temperature rise in the stator core 9 and winding 8. This effectively prevents problems such as insulation aging and demagnetization of the permanent magnet 2 caused by local overheating, thereby improving the reliability and lifespan of the motor during long-term operation. At the same time, the flushing effect of the coolant on the immersed components can reduce carbon deposits and impurity deposition, and the closed-loop system does not require additional fans or heat sinks, reducing operating noise and optimizing structural compactness. It is particularly suitable for scenarios with stringent requirements for power density and heat dissipation efficiency, such as new energy vehicles and aerospace.

[0036] Based on the requirements, the coolant is a known cooling oil, which can be transformer oil. As a heat dissipation medium for the motor, the core function of the cooling oil is to combine efficient heat dissipation with electrical insulation: on the one hand, due to its high specific heat capacity and fluidity, the cooling oil quickly absorbs the heat generated by core components such as the stator windings 8 and rotor magnets through direct contact or circulation, significantly reducing the motor's operating temperature and preventing efficiency degradation, insulation aging, or demagnetization of the permanent magnets 2 due to overheating; on the other hand, its excellent insulation properties (such as the high dielectric strength and low dielectric loss of transformer oil) can form reliable electrical isolation in the immersion cooling system, preventing short circuits or leakage risks in the windings 8, making it particularly suitable for high-voltage, high-power-density motor applications. Furthermore, the cooling oil also possesses good low-temperature fluidity (ensuring automatic convection heat dissipation in low-temperature environments) and oxidation stability (extending service life), while reducing impurity deposition in the cooling system, lowering maintenance requirements, and thus improving the long-term reliability of the motor and the system integration. In addition, transformer oil also plays a lubricating role. Its non-corrosiveness and thermal stability help reduce friction and wear between the upper bearing 17 and the lower bearing 18, thereby improving the service life and reliability of the bearings, and thus improving the long-term reliability of the motor and the system integration.

[0037] Depending on the requirements, the stator assembly can utilize PCB winding 8 (i.e., replacing the traditional hand-wound copper coils with printed circuit boards). This structural innovation significantly improves motor performance and manufacturing efficiency: Firstly, PCB winding 8 integrates complex electromagnetic circuitry into a multi-layered circuit board, greatly simplifying the stator structure and achieving a more compact and lightweight design. This is particularly suitable for flat configurations such as axial flux motors, effectively increasing the flux area and torque density. Secondly, its standardized printing process eliminates the inconsistencies of hand-wound winding, optimizes the electromagnetic field distribution, and, combined with the low-resistance copper foil conductive path, reduces copper losses and improves energy conversion efficiency. Furthermore, PCB winding 8 possesses excellent thermal conductivity, facilitating integration with cooling systems. Automated production also reduces manufacturing costs, providing crucial technical support for high power density, high reliability, and large-scale application of the motor.

[0038] The above-mentioned axial flux motor can be further optimized and / or improved according to actual needs: Example 2: As shown in the attached document Figures 1 to 10As shown, 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 circumferentially along 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, with the core 9 inside the winding 8. Several vertically penetrating cooling grooves 43 are evenly distributed circumferentially along the outer side of the mounting cylinder 10. A through-hole 45 is provided in the cooling groove 43 corresponding to the lower position of the spacers 11. 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 force or vibration, 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.

[0039] Example 3: As shown in the attached document Figure 9As shown, the stator support also includes a stop block 13. Each spacer 11 has a stop block 13 at its inner center. The stop block 13 is T-shaped, narrower on the outside and wider on the inside. The mounting cylinder 10, spacer 11, and stop block 13 are integrally formed. A rounded corner smoothly transitions between the mounting cylinder 10 and the outer sides of the spacer 11, and a rounded corner smoothly transitions between the stop block 13 and the inner sides of the spacer 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 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.

[0040] Example 4: As shown in the appendix Figure 10As shown, the stator support also includes a retaining ring 14. The retaining ring 14 is installed inside the mounting cylinder 10. The retaining ring 14 and the corresponding positions at the inner center of each spacer plate 11 are fixed together. 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 also 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.

[0041] Example 5: As shown in the attached document Figures 1 to 10As shown, the rotor assembly includes a rotor support 1, a permanent magnet 2, and a bushing 3. The bushing 3 has an outer annular groove 5 on its upper outer side. The rotor support 1 is fixedly installed in the outer annular groove 5. The rotor support 1 is circular. Several vertically penetrating mounting holes 4 are evenly distributed along the circumference on the upper side of the rotor support 1. The mounting holes 4 are fan-shaped and contain permanent magnets 2. The upper rotor assembly includes a rotor back iron 22, a silicon steel disc 23, and end permanent magnets 24 arranged sequentially from top to bottom. Several end permanent magnets 24 are evenly distributed along the circumference on the lower side of the silicon steel disc 23. The end permanent magnets 24 are fan-shaped. Several cooling holes 44 are evenly distributed along the circumference on both the rotor support 1 and the rotor back iron 22. The lower rotor assembly 25 has the same structure as the upper rotor assembly and is arranged symmetrically from top to bottom. During use, the rotor support 1 facilitates the installation of the permanent magnet 2; the bushing 3 facilitates the overall installation of the rotor support 1 on the outside of the motor shaft 16, thus achieving rapid assembly; the upper rotor assembly and lower rotor assembly 25, formed by the combination of the rotor back iron 22, silicon steel disc 23 and end permanent magnet 24, play a key role in constructing an efficient magnetic circuit and optimizing electromagnetic performance. Among them, the permanent magnet 2 (such as neodymium iron boron) provides a stable magnetic field; the silicon steel disc 23 effectively conducts magnetic flux with its high magnetic permeability, thereby enhancing the magnetic field strength, and its low iron loss characteristics reduce eddy current losses; the rotor back iron 22 is a key component for magnetic circuit closure, and its magnetic circuit closure design further optimizes the magnetic flux path, reduces leakage flux and enhances the magnetic field strength, ensuring that electromagnetic energy is efficiently converted into mechanical energy.

[0042] Example 6: As shown in the appendix Figures 1 to 10 As shown, it also includes an end bushing 19. The end bushing 19 and the inner side of the bushing 3 are provided with spline grooves 7. Between each pair of adjacent stator assemblies, a rotor assembly is installed on the outside of the motor shaft 16 via a spline connection. The rotor bracket 1 is located inside the mounting cylinder 10 below the corresponding spacer plate 11. The uppermost bushing 3 has an end bushing 19 installed on the outside of the motor shaft 16 via a spline connection. The upper outer side of the end bushing 19 has an upper mounting ring groove 20. An upper rotor assembly located above the stator assembly is located outside the upper mounting ring groove 20. The lower outer side of the lower end of the bushing 3 has a lower mounting ring groove 21. A lower rotor assembly 25 located inside the mounting cylinder 10 below the corresponding spacer plate 11 is located outside the lower mounting ring groove 21. During use, the spline grooves 7 on the inner sides of the bushings 3 and 19, in conjunction with the splines on the outside of the motor shaft 16 and using an interference fit, achieve torque transmission and axial positioning, ensuring coaxiality and reducing vibration. According to the requirements, the rotor support 1 and the rotor back iron 22 can be provided with keyways, and the bushing 3 and the end bushing 19 corresponding to the keyway position are provided with key blocks located in the keyways.

[0043] Example 7: As attached Figures 1 to 10As shown, both the end permanent magnet block and the permanent magnet 2 consist of several permanent magnet blocks cut into segments along the circumference. During use, the permanent magnet 2 generates eddy currents in the alternating magnetic field, leading to energy loss and temperature rise. By cutting the end permanent magnet block and the permanent magnet 2 into multiple permanent magnet blocks along the circumference, the entire magnet is divided into multiple insulated and isolated sector blocks, which can significantly shorten the eddy current loop path and reduce the eddy current effect. After segmentation, the permanent magnet 2 can flexibly control the harmonic content of the rotor magnetic field by adjusting the size, angle, or magnetization direction of the sector blocks, reducing torque pulsation and improving the smoothness of motor operation. Depending on the requirements, the permanent magnet 2 uses diamond wire cutting or laser precision cutting technology to divide the sintered NdFeB and other hard and brittle permanent magnet materials into sector blocks along the circumference. The cutting accuracy needs to be controlled at the micrometer level to ensure that the gaps between the magnets are uniform and insulated. The space between the segmented permanent magnet blocks is 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.

[0044] Example 8: As attached Figures 1 to 10 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 improves mechanical stability. Axial positioning ensures uniformity of the 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 the smoothness of motor operation. Simultaneously, precise positioning ensures the magnetic field coupling efficiency between multiple sets of stator assemblies and the rotor permanent magnet 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.

[0045] Example 9: As attached Figures 1 to 10As shown, it also includes a threaded retaining ring 35, 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 35 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 35 and the lower bearing 18. During use, the threaded retaining ring 35, the locking washer 34, and the retaining ring 35 cooperate with the positioning ring 38 set 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 set 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 35 provides axial preload to ensure that the rotor assembly does not move axially. The locking washer 34 mechanically locks the threaded retaining ring 35 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.

[0046] Example 10: As attached Figure 1 As shown, in conjunction with the content of Examples 8 to 9, this paper discusses how to solve the core difficulty of air gap control in the existing manufacturing process when the multi-component stacked structure adopted by the present invention increases the power density by increasing the electromagnetic interaction area.

[0047] 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.

[0048] 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.

[0049] 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.

[0050] 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.

[0051] In the specific design and implementation process of this invention, (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 8). (2) Solving the positioning between the rotor and the motor shaft 16: By using the threaded retaining ring 35, 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 9). 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 9 As shown.

[0052] The multi-component stacked structure adopted in the preferred embodiment of the present invention 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.

[0053] 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.

[0054] 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.

[0055] 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.

[0056] 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.

[0057] The key performance parameters of this axial flux motor were determined through precise simulation and verification using finite element analysis (FEA) software. These parameters include, but are not limited to: rated voltage (VDC), rated power (kW), peak power (kW), rated speed (rpm), peak speed (rpm), rated torque (N·m), peak torque (N·m), maximum efficiency (%), cooling method, overall dimensions (length × width × height, mm), and total weight (kg). These parameters collectively constitute a quantitative characterization system for the motor's performance. Among them, the electrical parameters (voltage, power, speed, and torque) define the motor's operating range and power output capability, the maximum efficiency reflects the economy of energy conversion, and the cooling method and structural dimensions (weight) are directly related to thermal management efficiency and system integration adaptability, providing complete data support for motor design optimization, performance evaluation, and application matching.

[0058] Performance tests were conducted on this invention. The existing in-hub motor ICS600K was used as Comparative Example 1, and the existing in-hub motor ICS70K as Comparative Example 2. The performance test results are shown in Table 1. This invention demonstrates a significant technical advantage in power density: under conditions similar to Comparative Example 1 in rated power, its volume and mass are significantly lower, reflecting excellent lightweight and compact design; while with an outer diameter comparable to Comparative Example 2, its rated power significantly exceeds that of Comparative Example 2, highlighting higher energy output per unit volume. This dual-dimensional performance comparison fully verifies the outstanding technical advantages of this axial flux motor in improving power density, optimizing space utilization, and enhancing system integration adaptability.

[0059] Example 11: As shown in the appendix Figures 1 to 11 As shown, the electric cylinder using the aforementioned axial flux motor includes a cylinder body 46, an axial flux motor, a planetary roller screw, a piston rod 48, and a brake device 49. The cylinder body 46 houses the axial flux motor, the planetary roller screw, and the brake device. The piston rod 48, which can extend outwards, is also located within the cylinder body 46. The output end of the motor shaft 16 of the axial flux motor is connected to the nut end of the planetary roller screw, and the screw end of the planetary roller screw is connected to the piston rod 48. The cylinder body 46 contains a brake device 49 capable of braking the axial flux motor. In use, this embodiment is applied to a low-speed motor.

[0060] Example 12: As attached Figures 1 to 11As shown, the electric cylinder using the aforementioned axial flux motor includes a cylinder body 46, an axial flux motor, a reducer 47, a planetary roller screw, a piston rod 48, and a brake device 49. The cylinder body 46 houses the axial flux motor, the reducer 47, and the planetary roller screw, and also houses the piston rod 48, which can extend outward. The motor shaft 16 of the axial flux motor is connected to the input end of the reducer 47, the output end of the reducer 47 is connected to the nut end of the planetary roller screw, and the screw end of the planetary roller screw is connected to the piston rod 48. The cylinder body 46 houses a brake device 49 for braking the axial flux motor.

[0061] During use, the dimensions of this electric cylinder can replace the hydraulic cylinders used in common engineering machinery. The connection between the axial flux motor, reducer 47, planetary roller screw, and piston rod 48 in the electric cylinder needs to form a complete power transmission chain to achieve precise conversion from rotary motion to linear motion. The specific connection method and functional implementation are as follows: (1) Connection between axial flux motor and reducer 47: The output shaft of the axial flux motor is rigidly connected to the input end of reducer 47 through an eccentric sleeve. The eccentric sleeve is directly fitted onto the motor shaft 16, serving as the mounting base for the reducer shock wave generator. This design transmits the high speed and low torque output of the motor to the reducer, using the reducer (such as a live gear reducer or planetary gear reducer) to increase the output torque and reduce the speed, providing suitable power parameters for the subsequent screw drive.

[0062] (2) Connection between reducer 47 and planetary roller screw: The output end of reducer 47 is directly coupled to the nut end of planetary roller screw through a pin or coupling. The rotary motion output by reducer 47 drives the screw nut to rotate. At this time, the rollers inside the planetary roller screw roll between the nut and the screw shaft, converting the rotary motion into the linear motion of the screw shaft. Because the planetary roller screw adopts a multi-roller contact structure, it has high load-bearing capacity, high rigidity and zero backlash characteristics, ensuring the accuracy and stability of linear motion.

[0063] (3) Connection between planetary roller screw and piston rod: The end of the planetary roller screw shaft is fixed to the piston rod 48 by a threaded connection or an integral structure. The threaded connection (such as internal or external thread engagement) allows for quick disassembly and fine-tuning of the position, while the integral design integrates the screw shaft and piston rod 48 into a single component through machining, eliminating connection gaps and improving overall rigidity. The piston rod 48 extends and retracts synchronously with the linear movement of the screw shaft, directly outputting thrust or pull force to the external load.

[0064] In this embodiment, through the above connection method, the electric cylinder forms a complete transmission chain of "motor → deceleration and torque increase → lead screw rotation to linear conversion → piston rod output".

[0065] The braking device 49 used in axial flux motors typically employs an electromagnetic brake to suit its compact structure and high power density. This type of brake achieves rapid release by generating a magnetic field when energized to attract the brake pads, and quickly engages the brakes when de-energized by spring force, offering advantages such as sensitive response and precise control. Its core components include an electromagnetic coil, friction pads, and an armature. The working principle is based on the synergistic effect of electromagnetic force and a mechanical spring: when energized, the electromagnetic force overcomes the spring force, causing the brake pads to separate, allowing the motor to rotate freely; when de-energized, the spring returns to its original position, pushing the brake pads against the braking surface to achieve efficient braking. This type of device is particularly suitable for the frequent start-stop requirements of axial flux motors in electric vehicles, industrial automation, and other scenarios. It meets dynamic response requirements and, due to its compact structure, is easily integrated into the motor end without occupying additional axial space. Furthermore, the low maintenance and high reliability of the electromagnetic brake further ensure the stable operation of the axial flux motor system under harsh operating conditions.

[0066] Applying axial flux motor-driven electric cylinders to construction machinery and replacing traditional hydraulic systems, by replacing oil cylinders with electric cylinders and hydraulic travel motors with electric motors, achieves a revolutionary improvement in energy efficiency. Traditional hydraulic systems require multiple conversion stages during energy transfer, including pumps, valves, and pipelines, resulting in unavoidable leakage losses and heat dissipation, leading to significant energy wastage. In contrast, electric cylinders are directly driven by axial flux motors. Their unique flat structure provides extremely high torque density, and combined with optimized electromagnetic design, achieves a qualitative leap in energy conversion efficiency. Precise electronic control systems can adjust power output in real time, minimizing losses throughout the entire energy chain from input to execution, thereby significantly reducing overall machine energy consumption and carbon emissions, laying the foundation for the green development of construction machinery.

[0067] At the same time, this technology completely eliminates the inherent defects and maintenance burdens of hydraulic systems. Traditional hydraulic systems rely on hydraulic oil as the power transmission medium, requiring regular replacement of oil, seals, and filters. Oil leaks not only cause environmental pollution but can also lead to equipment malfunctions. Fluctuations in oil temperature can further destabilize system performance, affecting operational accuracy. Electric systems, on the other hand, completely eliminate dependence on hydraulic oil, fundamentally preventing leaks and oil contamination, and eliminating the costs of complex pipeline maintenance and oil changes. Because there is no risk of actuator jamming due to oil deterioration, equipment reliability is significantly improved, operational continuity is fully guaranteed, and maintenance costs throughout the entire lifecycle are significantly reduced.

[0068] Furthermore, electrification significantly optimizes the dynamic performance and intelligence level of construction machinery. Electric cylinders offer a much faster response speed than hydraulic systems, enabling instantaneous start / stop and precise speed adjustment to meet the demands of delicate operations under complex conditions. Their positioning accuracy reaches the micrometer level, making them particularly suitable for high-precision construction scenarios. Eliminating bulky components such as hydraulic pump stations and oil tanks significantly reduces the overall weight of the equipment, resulting in a more compact and flexible structural layout, improving space utilization and mobility. The electronic control system can monitor key parameters such as load, temperature, and vibration in real time, achieving adaptive adjustment and fault warning through algorithms, and supporting remote diagnostics and programmed control. This not only provides technical support for unmanned and automated operation of construction machinery but also promotes networked collaboration between equipment, accelerating the industry's transformation and upgrading towards intelligence and digitalization, and reshaping the technological ecosystem and competitive landscape of construction machinery.

[0069] The above technical features constitute the embodiments of the present invention, 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. An axial flux motor, characterized in that... The components include 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 motor shaft, with its upper and lower ends located outside the housing, is installed inside 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 inside the housing, arranged sequentially from top to bottom. Above the uppermost stator assembly is an upper rotor assembly mounted on the outside of the motor shaft. Between every two adjacent stator assemblies, a rotor assembly mounted on the outside of the motor shaft is also present. Below the stator assembly at the bottom, there is a lower rotor assembly mounted on the outside of the motor shaft. The upper rotor assembly, rotor assembly, and lower rotor assembly are sequentially positioned and mounted on the outside of the motor shaft from top to bottom. At least one coolant inlet hole is provided at circumferential intervals on the lower outer side of the housing corresponding to the position below the lower rotor assembly, and at least one coolant outlet hole is provided at circumferential intervals on the upper outer side of the housing corresponding to the position above the upper rotor assembly. Several vertically penetrating cooling grooves are provided on the outside of the stator assembly, and several vertically penetrating cooling holes are provided on the rotor assembly, upper rotor assembly, and lower rotor assembly.

2. The axial flux motor according to claim 1, characterized in that... The stator assembly includes a stator support, windings, and an iron core. The stator support includes a mounting cylinder and spacers. Several spacers are evenly distributed around 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. Several vertically penetrating cooling grooves are evenly distributed around the circumference on the outer side of the mounting cylinder. The cooling grooves corresponding to the lower position of the spacers have through holes that penetrate both inside and outside.

3. The axial flux motor according to claim 2, characterized in that... The stator support also includes a stop block, with a stop block located at the center 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. There is 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. Alternatively, the stator support also includes a retaining ring, with a retaining ring located inside the mounting cylinder. The retaining ring and the corresponding position at the center of the inner end of each partition plate are fixed together. The mounting cylinder, partition plate, and retaining ring are integrally formed. There is 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 retaining ring and the inner sides of the partition plate.

4. The axial flux motor according to claim 1, 2, or 3, characterized in that... The rotor assembly includes a rotor support, permanent magnets, and a bushing. The upper outer side of the bushing has an outer annular groove, and the rotor support is fixedly installed in the outer annular groove. The rotor support is circular, and 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 upper rotor assembly includes a rotor back iron, a silicon steel disc, 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 disc. The end permanent magnets are fan-shaped. Several cooling holes are evenly distributed along the circumference on both the rotor support and the rotor back iron. The lower rotor assembly has the same structure as the upper rotor assembly and is arranged symmetrically.

5. The axial flux motor according to claim 4, characterized in that... It also includes end bushings, with spline grooves on the inner side of the end bushings and the bushings. Between each pair of adjacent stator assemblies, there is a rotor assembly 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. The upper side of the bushing at the uppermost position is provided with an end bushing installed on the outside of the motor shaft via a spline connection. The upper outer side of the end bushing is provided with an upper mounting ring groove. The upper rotor assembly located above the stator assembly is located on the outer side of the upper mounting ring groove. The lower outer side of the bushing at the lowermost position is provided with a lower mounting ring groove. The 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. Or / and, the end permanent magnet blocks and permanent magnets both include several permanent magnet blocks that are cut into segments along the circumferential direction.

6. The axial flux motor according to claim 1, 2, 3, or 5, 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.

7. The axial flux motor according to claim 4, 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.

8. The axial flux motor according to claim 6, 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.

9. The axial flux motor according to claim 7, 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.

10. An electric cylinder using an axial flux motor as described in any one of claims 1 to 9, characterized in that... It includes a cylinder block, an axial flux motor, a reducer, a planetary roller screw, and a piston rod. The cylinder block houses the axial flux motor, the reducer, and the planetary roller screw, and also houses a piston rod that can extend outward. The motor shaft of the axial flux motor is connected to the input end of the reducer, the output end of the reducer is connected to the nut end of the planetary roller screw, and the screw end of the planetary roller screw is connected to the piston rod.

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