Rotor fan integrated permanent magnet generator

Abstract

This invention discloses a rotor-fan integrated permanent magnet generator, comprising a stator assembly, a rotor assembly, end covers, and bearing assemblies. The rotor assembly is an integrated structure, consisting of a fan-shaped magnetic core made of magnetically conductive composite material and permanent magnets embedded in the magnetic core. The fan-shaped magnetic core includes an integrally formed central rotating shaft sleeve and blade-shaped magnetic guide teeth evenly distributed circumferentially on the outside of the central rotating shaft sleeve. The blade-shaped magnetic guide teeth act as heat dissipation fan blades, achieving the dual functions of magnetic excitation and forced air cooling when the rotor assembly rotates. The permanent magnets are installed at the ends of the blade-shaped magnetic guide teeth away from the central rotating shaft sleeve, with a pre-reserved magnetic isolation gap between adjacent blade-shaped magnetic guide teeth to ensure directional magnetic conduction. This invention, through an innovative design of integrated structure and functional reuse, integrates the rotor magnetic core and heat dissipation fan blades into a single component, enabling it to simultaneously achieve magnetic excitation and heat dissipation functions. It has the advantages of low manufacturing cost, simple assembly, wide adaptability, and high reliability.

Description

Technical Field

[0001] This invention relates to the field of generator technology, and in particular to a rotor-integrated high-efficiency permanent magnet generator, which is suitable for small permanent magnet generators, portable generators, vehicle-mounted generators and distributed micro generators. Background Technology

[0002] Permanent magnet generators are widely used in portable power supply, vehicle power supply, and distributed micro-generation due to their compact structure and high energy conversion efficiency. In traditional permanent magnet generators, the rotor magnetic structure and the cooling fan are two completely independent components. The rotor core uses a magnetic material to achieve the excitation function of magnetic circuit conduction, while the cooling fan is mostly made of plastic or non-magnetic metal to achieve the heat dissipation function. The two need to be assembled into one unit through a connecting bracket and then connected to the generator shaft.

[0003] This split-type structural design has several technical drawbacks: First, the assembly of multiple components, including the rotor core, connecting bracket, and independent fan blades, is prone to coaxiality deviations, increasing electromagnetic losses and reducing power generation efficiency during rotor rotation. Second, the presence of the connecting bracket obstructs airflow, significantly increasing wind resistance. Furthermore, the gap between the fan blades and the rotor / stator heat dissipation areas prevents airflow from directly reaching the heat-generating parts, resulting in low heat dissipation efficiency and excessively high generator operating temperatures. Third, the large number of parts and complex assembly processes increase manufacturing costs and assembly time. Fourth, the connection between the fan blades and the rotor relies on the bracket, and permanent magnets are mostly fixed by adhesive bonding. Under complex working conditions such as outdoors and on construction sites, components are prone to loosening and magnets may fall off, leading to poor equipment reliability and short maintenance cycles.

[0004] Currently, improvements to permanent magnet generators in the industry are mostly focused on optimizing electromagnetic parameters and adjusting stator winding structures. None of these have broken through the inherent concept of "separate design of rotor magnetic conduction and fan blade heat dissipation." There is still no technical solution that integrates the fan blade and rotor core into a single design, and enables the fan blade to have both magnetic conduction and heat dissipation functions. Therefore, it is impossible to fundamentally solve the series of problems caused by the aforementioned separate structure.

[0005] In existing related patent technologies, such as the permanent magnet generator rotor disclosed in patent document (CN101640442A), the only means of cooling is the "gap between the yoke platforms acting as a cooling air duct," which is a passive heat dissipation design. This restricts airflow paths, preventing directional forced convection and hindering efficient heat removal from the permanent magnets and yoke. For high-power wind turbines, excessive temperature rise in the permanent magnets can lead to irreversible demagnetization, affecting generator lifespan and output stability. The rotor consists of multiple independent components, including a cylindrical yoke, tile-shaped yoke platforms, tile-shaped permanent magnets, a shaft, and spokes. Each component requires separate machining of countersunk / stepped holes, through holes, and mounting holes, and is secured with multi-stage fastening using non-magnetic stainless steel bolts. Precise alignment is crucial, and accumulated tolerances can affect air gap uniformity, increasing debugging difficulty and assembly time. Furthermore, the magnetic guiding components (yoke and yoke platforms) are completely separated from the heat dissipation function, failing to achieve "multi-purpose materials and multi-functional structures." While the gap between the yoke platforms serves as an air duct, the lack of flow guidance and pressurization design limits the improvement in heat dissipation efficiency.

[0006] Therefore, there is an urgent need for a rotor-integrated permanent magnet generator that can achieve magnetic excitation and heat dissipation functions through an innovative design that integrates structure and reuses functions, thereby improving power generation and heat dissipation efficiency. Summary of the Invention

[0007] This invention addresses the technical pain points of existing permanent magnet generators by providing a rotor-fan integrated permanent magnet generator. Through an innovative design that combines structural integration and functional reuse, the rotor magnetic core and the cooling fan are integrated into a single component, enabling it to simultaneously perform magnetic excitation and heat dissipation functions. This fundamentally eliminates coaxiality deviation, reduces wind resistance, simplifies the structure, and improves power generation and heat dissipation efficiency. Furthermore, it boasts advantages such as low manufacturing cost, simple assembly, wide adaptability, and high reliability.

[0008] To achieve the above objectives, the technical solution of the present invention is: a rotor-fan integrated permanent magnet generator, comprising a stator assembly, a rotor assembly, an end cover, and a bearing assembly. The bearing assembly is installed inside the end cover, and the rotor assembly is rotatably coupled to the bearing assembly via a rotating shaft. The stator assembly is coaxially sleeved on the outside of the rotor assembly. The stator assembly has 24 stator winding slots. The rotor assembly is an integrated structure, consisting of a fan-shaped magnetic core made of magnetically conductive composite material and six permanent magnets embedded in the fan-shaped magnetic core. The fan-shaped magnetic core includes an integrally formed central rotating shaft sleeve and blade-shaped magnetic teeth evenly distributed circumferentially on the outside of the central rotating shaft sleeve. The blade-shaped magnetic teeth serve as heat dissipation fan blades, achieving the dual functions of magnetic excitation and forced air cooling when the rotor assembly rotates. The permanent magnets are installed at the ends of the blade-shaped magnetic teeth away from the central rotating shaft sleeve, and a magnetic isolation gap is reserved between adjacent blade-shaped magnetic teeth. The width of the magnetic isolation gap is 2-5mm to ensure directional magnetic transmission.

[0009] Furthermore, the magnetically conductive composite material is a mixture of silicon steel powder and epoxy resin for die casting. The silicon steel powder is the magnetically conductive material, and the epoxy resin is the binder phase. After die casting, it has both good magnetic conductivity and mechanical strength, meeting the structural strength requirements of generator magnetic circuit conduction and outdoor working conditions.

[0010] Furthermore, the number of blade-type magnetic guide teeth is adapted to the number of stator winding slots of the stator assembly to meet the base slot fit. The blade-type magnetic guide teeth have an arc-shaped structure, which forms an axial directional airflow when the rotor assembly rotates. The airflow blows directly over the windings of the stator assembly and the rotor assembly itself without obstruction, achieving precise heat dissipation.

[0011] Furthermore, the number of the blade-type magnetic guide teeth is 6-12.

[0012] Furthermore, the arc-shaped structure of the blade-type magnetic guide teeth results in low wind resistance and direct contact with the stator and rotor heat dissipation areas along with the rotor, allowing unobstructed airflow to reach the heat-generating parts, thereby improving heat dissipation efficiency by 30% and reducing the generator operating temperature rise by more than 20°C.

[0013] Furthermore, the permanent magnet is a neodymium iron boron permanent magnet block, and the end of the blade-type magnetic guide tooth is provided with a mounting slot adapted to the neodymium iron boron permanent magnet block. The permanent magnet can be detachably installed in the mounting slot through a snap-fit ​​structure.

[0014] Furthermore, the permanent magnet adopts a snap-on detachable connection structure, eliminating the need for adhesive bonding and removing the vulnerable structure of the connecting bracket and adhesive magnet. This makes assembly and replacement convenient and increases the maintenance-free cycle by more than 50%.

[0015] Furthermore, the magnetic isolation gap contains an air medium, which effectively blocks magnetic circuit crosstalk between adjacent blade-type magnetic guide teeth, ensuring directional transmission of the magnetic circuit to the stator assembly and improving electromagnetic conversion efficiency.

[0016] Furthermore, the integrated rotor assembly is directly assembled with the shaft and bearing assembly without the need to adjust the coaxiality, thereby reducing the number of generator parts by 40% and the assembly process by 50%.

[0017] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0018] 1. Extremely simplified structure and significantly improved assembly efficiency: The three core components of traditional generators, namely the independent cooling fan blade, the fan blade connecting bracket, and the traditional rotor core, have been eliminated, reducing the number of generator parts by 40% and the assembly process by 50%. The integrated rotor assembly can be directly assembled with the shaft and bearing assembly without adjusting the coaxiality. Ordinary production plants can achieve mass production without adding new equipment, making the assembly threshold extremely low.

[0019] 2. Dual improvement in power generation and heat dissipation efficiency: The integrated structure fundamentally eliminates the coaxiality deviation of the separate assembly, ensuring smooth rotor rotation, reducing electromagnetic losses, and greatly improving power generation efficiency; the blade-type magnetic guide teeth have an arc-shaped structure, resulting in low wind resistance and direct contact with the stator and rotor heat dissipation areas along with the rotor, allowing unobstructed airflow to reach the heat-generating parts directly, improving heat dissipation efficiency by 30% and reducing the generator operating temperature rise by more than 20°C.

[0020] 3. Low manufacturing cost and no additional energy consumption: It reduces the procurement cost of independent components and the labor cost of multiple assembly processes. Moreover, the heat dissipation function is achieved by the rotation of the rotor itself, without the need for additional auxiliary fans and drive energy consumption, resulting in low cost over the entire life cycle.

[0021] 4. Wide adaptability and low modification cost: The stator assembly adopts a conventional winding structure without any modifications. Only the traditional split rotor needs to be replaced with the integrated rotor assembly of this invention to transform the existing traditional permanent magnet generator into the high-efficiency generator of this invention. It is suitable for all small permanent magnet power generation scenarios such as small permanent magnet generators, portable generators, vehicle-mounted generators, and distributed micro generators. 5. High structural reliability and long maintenance-free period: The fan-type magnetic core is integrally die-cast, resulting in high structural strength; the permanent magnet adopts a snap-on detachable connection, eliminating the need for bonding and removing vulnerable structures such as connecting brackets and bonded magnets. It can adapt to complex working conditions such as outdoor, construction site, and vehicle-mounted applications, significantly reducing equipment failure rate and increasing the maintenance-free period by more than 50%. Attached Figure Description

[0022] Figure 1 This is an axial cross-sectional view of the rotor-fan integrated permanent magnet generator of the present invention; Figure 2 This is a radial cross-sectional view of the rotor-integrated permanent magnet generator of the present invention.

[0023] Figure 3 This is an overall diagram of the rotor-integrated permanent magnet generator of the present invention. Detailed Implementation

[0024] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention.

[0025] like Figures 1 to 3 As shown in the figure, an embodiment of the present invention provides a rotor-fan integrated high-efficiency permanent magnet generator, suitable for portable small permanent magnet generators, including a stator assembly 1, a rotor assembly 3, a stator winding 4, a bearing assembly 5, a shaft 6, and an end cover 7. The bearing assembly 5 is installed inside the end cover 7, and the rotor assembly 3 is rotatably engaged with the bearing assembly 5 through the shaft 6. The stator assembly 1 is coaxially sleeved on the outside of the rotor assembly 3, and the stator winding 4 of the stator assembly 1 has 24 slots.

[0026] Rotor assembly 3 is an integrated die-cast structure, consisting of a fan-shaped magnetic core made of magnetically conductive composite material and six neodymium iron boron permanent magnet blocks. The magnetically conductive composite material is a mixture of silicon steel powder and epoxy resin, die-cast into a single unit through high-temperature die casting to form the fan-shaped magnetic core. The silicon steel powder serves as the magnetic conductive material, and the epoxy resin as the binder phase. After die casting, it possesses both excellent magnetic conductivity and mechanical strength, meeting the structural strength requirements for generator magnetic circuit conduction and outdoor operating conditions. The number of blade-shaped magnetic teeth matches the number of stator winding slots in the stator assembly, ensuring a proper slot fit. Specifically, there are 6-12 blades. The blade-shaped magnetic teeth have an arc-shaped structure, forming an axial directional airflow as the rotor assembly rotates. This unobstructed airflow directly passes over the stator windings and the rotor assembly itself, achieving precise heat dissipation.

[0027] In this embodiment, the magnetic core includes a central rotating shaft sleeve and six blade-type magnetic guide teeth 8 evenly distributed around the outside of the central rotating shaft 6. The blade-type magnetic guide teeth 8 have an arc-shaped structure, and their number is adapted to the number of slots in the stator winding 4, while also serving as heat dissipation fan blades.

[0028] The permanent magnet is a neodymium iron boron permanent magnet block. The end of the blade-type magnetic guide tooth is provided with a mounting slot that is compatible with the neodymium iron boron permanent magnet block. The permanent magnet can be detachably installed in the mounting slot through a snap-on structure without the need for adhesive, making assembly and replacement convenient.

[0029] Each blade-type magnetic guide tooth 8 has a mounting slot at its end away from the central rotating shaft 6. The neodymium iron boron permanent magnet block can be detachably installed in the mounting slot through a snap-fit ​​structure. A 2-5mm magnetic isolation gap is reserved between adjacent blade-type magnetic guide teeth. The gap is filled with air medium to block magnetic circuit crosstalk, ensure the magnetic circuit is directionally conducted to the stator assembly, and improve the electromagnetic conversion efficiency.

[0030] This invention eliminates the independent fan blades, connecting brackets, and traditional rotor core, reducing the number of parts by 40% and assembly steps by 50%. The integrated structure eliminates coaxiality deviation, significantly reducing electromagnetic losses and improving power generation efficiency. The arc-shaped blade-type magnetic guide teeth have low wind resistance, allowing airflow to directly reach the heat dissipation area, improving heat dissipation efficiency and reducing temperature rise by more than 20°C. The permanent magnets use a snap-fit ​​connection, ensuring high structural reliability, and the stator assembly remains unchanged, making it suitable for all small permanent magnet generator scenarios. It also has low modification costs and is easy to mass-produce.

[0031] After the generator starts, the shaft drives the integrated rotor assembly to rotate coaxially around the stator assembly. Firstly, the blade-type magnetic guide teeth, as the core of the rotor's magnetic conduction, drive the permanent magnet to rotate synchronously, forming a relative cutting magnetic field line motion with the stator assembly's windings, generating induced electrical energy in the stator windings, thus realizing the power generation function of magnetic excitation. Secondly, the same set of blade-type magnetic guide teeth acts as cooling fan blades, pushing air to form an axial directional airflow when the rotor rotates at high speed. Because the traditional connecting brackets are eliminated, the airflow is unobstructed and blows directly over the stator windings and the heat-generating parts of the rotor assembly itself, quickly carrying away the working heat and realizing the forced air cooling function. Thirdly, the integrated structure eliminates the coaxiality deviation of the split design, making the rotor rotate more smoothly and significantly reducing electromagnetic losses. At the same time, the wind resistance of the arc-shaped blade-type magnetic guide teeth is much lower than that of the traditional split fan blades, further improving the heat dissipation efficiency.

Claims

1. A rotor-blade integrated permanent magnet generator, comprising a stator assembly, a rotor assembly, an end cover, and a bearing assembly, wherein the bearing assembly is mounted inside the end cover, the rotor assembly is rotatably coupled to the bearing assembly via a shaft, and the stator assembly is coaxially sleeved on the outside of the rotor assembly, the stator assembly having 24 stator winding slots, characterized in that: The rotor assembly is an integrated structure, consisting of a fan-shaped magnetic core made of magnetically conductive composite material and six permanent magnets embedded in the fan-shaped magnetic core. The fan-shaped magnetic core includes an integrally formed central rotating shaft sleeve and blade-shaped magnetic guide teeth evenly distributed around the outside of the central rotating shaft sleeve. The blade-shaped magnetic guide teeth serve as heat dissipation fan blades, realizing the dual functions of magnetic excitation and forced air cooling when the rotor assembly rotates. The permanent magnets are installed at the ends of the blade-shaped magnetic guide teeth away from the central rotating shaft sleeve, and a magnetic isolation gap is reserved between adjacent blade-shaped magnetic guide teeth. The width of the magnetic isolation gap is 2-5mm to ensure directional magnetic transmission.

2. The rotor-integrated permanent magnet generator according to claim 1, characterized in that: The magnetically conductive composite material is a mixture of silicon steel powder and epoxy resin for die casting. The silicon steel powder is the magnetically conductive material, and the epoxy resin is the binder phase. After die casting, it has both good magnetic conductivity and mechanical strength, meeting the structural strength requirements of generator magnetic circuit conduction and outdoor working conditions.

3. The rotor-integrated permanent magnet generator according to claim 1, characterized in that: The number of blade-type magnetic guide teeth is adapted to the number of stator winding slots of the stator assembly to meet the base slot fit. The blade-type magnetic guide teeth have an arc-shaped structure, which forms an axial directional airflow when the rotor assembly rotates. The airflow blows directly over the stator assembly windings and the rotor assembly itself without obstruction, achieving precise heat dissipation.

4. The rotor-integrated permanent magnet generator according to claim 3, characterized in that: The number of blade-type magnetic guide teeth is 6-12.

5. The rotor-integrated permanent magnet generator according to claim 3, characterized in that: The arc-shaped structure of the blade-type magnetic guide teeth has low wind resistance and directly fits the stator and rotor heat dissipation areas with the rotor, allowing airflow to reach the heat-generating parts without obstruction, thereby improving heat dissipation efficiency by 30% and reducing the generator operating temperature rise by more than 20°C.

6. The rotor-integrated permanent magnet generator according to claim 1, characterized in that: The permanent magnet is a neodymium iron boron permanent magnet block. The end of the blade-type magnetic guide tooth is provided with a mounting slot adapted to the neodymium iron boron permanent magnet block. The permanent magnet can be detachably installed in the mounting slot through a snap-fit ​​structure.

7. The rotor-integrated permanent magnet generator according to claim 6, characterized in that: The permanent magnet adopts a snap-on detachable connection structure, eliminating the need for adhesive bonding. This eliminates the vulnerable structure of connecting brackets and adhesive magnets, making assembly and replacement convenient and increasing the maintenance-free period by more than 50%.

8. The rotor-integrated permanent magnet generator according to claim 1, characterized in that: The magnetic isolation gap contains air, which effectively blocks magnetic circuit crosstalk between adjacent blade-type magnetic guide teeth, ensuring directional transmission of the magnetic circuit to the stator assembly and improving electromagnetic conversion efficiency.

9. The rotor-integrated permanent magnet generator according to claim 1, characterized in that: The integrated rotor assembly is directly assembled with the shaft and bearing assembly without the need to adjust the coaxiality, thereby reducing the number of generator parts by 40% and the assembly process by 50%.

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