Permanent magnet motor rotor and skew pole unit arrangement method thereof

Abstract

The application relates to the technical field of large wind-driven generator permanent magnet machines, in particular to a permanent magnet machine rotor and a skew pole unit arrangement method thereof. Skew pole units are uniformly and spacedly arranged on the outer surface of a rotor yoke, the skew pole units are composed of multiple magnetic pole assemblies, each magnetic pole assembly is embedded with a magnetic steel, a plurality of magnetic pole assemblies form a magnetic pole group, and multiple magnetic pole groups form a V-shaped groove in the axial direction on the outer surface of the rotor yoke. The core component of the permanent magnet machine rotor is a ring-shaped rotor yoke, the outer circumferential surface of the ring-shaped rotor yoke is provided with a magnetic field generating structure formed by regularly arranged skew pole units, each skew pole unit is composed of a plurality of independent magnetic pole assemblies, permanent magnets are embedded in the magnetic pole assemblies to provide an excitation source, a plurality of magnetic pole assemblies are paired to form a magnetic pole group, and multiple magnetic pole groups are arranged in the axial direction on the surface of the rotor yoke and are staggered at a specific angle to form a continuous V-shaped groove structure, so that the magnetic field distribution is optimized and the mechanical strength is ensured.

Description

Technical Field

[0001] This invention relates to the field of permanent magnet motor technology for large wind turbine generators, and in particular to a permanent magnet motor rotor and a method for arranging its skew pole units. Background Technology

[0002] During motor operation, the presence of cogging teeth in the iron core generates cogging torque, which is one of the causes of torque fluctuations. Currently, permanent magnet synchronous motors used in the market, especially semi-direct drive wind turbines, generally employ a combination of stator skewed slots and rotor non-skewed poles to weaken specific harmonics, thereby effectively reducing cogging torque and improving motor operating characteristics. However, because wind turbines have relatively large outer diameters, and the rotor poles are uniformly segmented circumferentially and axially, these segments are strongly magnetic and assembled. Using stator skewed slots introduces inconveniences in manufacturing and wiring, resulting in low efficiency. Furthermore, the skewed slots only tilt in one direction, generating unilateral axial forces that affect the stator-rotor balance and have a certain impact on the bearings.

[0003] Furthermore, as the rotor speed and diameter of semi-direct drive wind turbine generators increase, the centrifugal force also increases dramatically. In this situation, how to reliably and effectively fix the magnetic pole assembly to the rotor yoke under such large centrifugal forces becomes a critical issue.

[0004] In view of the above-mentioned shortcomings, the designer actively researched and innovated in order to create a permanent magnet motor rotor and its skew pole unit arrangement method, so as to make it more industrially valuable. Summary of the Invention

[0005] To solve the above-mentioned technical problems, the purpose of this invention is to provide a permanent magnet motor rotor and a method for arranging its skew pole units.

[0006] The present invention provides a permanent magnet motor rotor, including a rotor yoke, wherein skew pole units are evenly spaced on the outer surface of the rotor yoke, each skew pole unit is composed of multiple magnetic pole components, each magnetic pole component is embedded with a magnet, and several magnetic pole components form a magnetic pole group, and multiple magnetic pole groups form a "V" shaped groove on the outer surface of the rotor yoke in the axial direction.

[0007] The core component of a permanent magnet motor rotor is an annular rotor yoke. Its outer circumferential surface is composed of regularly arranged skewed pole units to form a magnetic field generating structure. Each skewed pole unit is composed of several independent magnetic pole component modules. Permanent magnets are embedded inside the magnetic pole components to provide an excitation source. Several magnetic pole components are paired to form a magnetic pole group. Multiple groups of magnetic pole components are arranged along the axial direction on the rotor yoke surface and are staggered at a specific angle to form a continuous V-shaped groove structure. This design not only optimizes the magnetic field distribution but also ensures the overall mechanical strength.

[0008] Furthermore, the outer surface of the rotor yoke is provided with multiple axially arranged positioning grooves, and positioning strips are fixed in the positioning grooves. The upper ends of the positioning strips extend outward on both sides to form positioning guide strips, and the magnetic pole assembly has guide grooves on both sides that cooperate with the positioning guide strips.

[0009] The outer circumferential surface of the rotor yoke is machined with several axially extending positioning grooves. Rigid positioning strips are embedded in the grooves as basic guiding structures. The positioning guide strips at the top of the positioning strips form a stable double-wing support interface. The magnetic pole assembly has precision-machined guide grooves on both sides that match the geometric contour of the positioning guide strips. Through sliding engagement, the magnetic pole assembly is accurately positioned circumferentially and supported radially on the rotor surface.

[0010] Furthermore, a first baffle and a second baffle are fixed at both ends of every two adjacent positioning strips. The inner sidewalls of the first baffle and the second baffle are in contact with the magnetic pole assemblies at both ends of the inclined pole unit, providing outer end limit for the magnetic pole assemblies.

[0011] The first baffle and the second baffle, which are respectively assembled at both ends of the adjacent positioning strip, form a closed limiting structure. The inner working surfaces of the first baffle and the second baffle are closely attached to the outer surfaces of the magnetic pole assemblies at both ends of the inclined pole unit, forming a two-way mechanical constraint on the magnetic pole assemblies. This design not only ensures the precise positioning of the magnetic pole assemblies in the rotor circumferential direction, but also achieves two-way blocking of axial displacement through the direct contact between the baffle and the magnetic pole assemblies, thereby maintaining the overall stability of the magnetic pole assembly array under high-speed rotation conditions.

[0012] Furthermore, each magnetic pole assembly has a through hole in the middle, through which a locking screw passes. Locking nuts are screwed into both ends of the locking screw, and the locking nuts contact the outer walls of the corresponding first and second baffles. The lower arc-shaped surfaces of the first and second baffles are in contact with the outer surface of the rotor yoke, and the outer surface of the first baffle is in contact with the inner wall of the protruding retaining ring on the outer edge of the rotor yoke.

[0013] A high-strength locking screw passes through the central through-hole of the magnetic pole assembly, and its two ends are axially locked by locking nuts. The end face of the locking nut forms rigid contact with the outer plane of the first baffle and the second baffle. At the same time, the arc-shaped contour surface of the lower edge of the baffle is in seamless contact with the outer circle of the rotor yoke, while the outer positioning surface of the first baffle is in tight contact with the inner wall of the retaining ring at the edge of the rotor yoke. This composite constraint system achieves all-round mechanical locking of the magnetic pole assembly in the rotor circumferential direction, axial direction and radial direction through the triple synergistic effect of the screw axial preload, the radial contact surface of the baffle and the positioning surface of the retaining ring, ensuring the structural integrity of the magnetic pole assembly under high centrifugal force conditions.

[0014] Furthermore, there is a spacer sleeved on the locking screw between two adjacent magnetic pole components in the skewed pole unit. The spacer is used to separate the two magnetic pole components, so that there is a gap between the magnetic pole components. A ventilation groove corresponding to each gap is opened on the circumference of the rotor yoke below the gap. The gap and ventilation groove are used for airflow to pass through.

[0015] The spacer is precisely fitted onto the locking screw that runs through the magnetic pole assembly to form a physical isolation layer, so that a constant gap space is maintained between adjacent magnetic pole assemblies. This gap and the corresponding ventilation groove opened on the circumferential surface of the rotor yoke form a continuous ventilation path. When the rotor rotates at high speed, an axial airflow channel is formed that runs through the gap between the magnetic pole assemblies and the ventilation groove. This not only realizes the equidistant positioning function between the magnetic pole assemblies, but also effectively reduces eddy current loss and temperature rise through directional airflow, while maintaining the dynamic balance and stability of the rotor system.

[0016] Furthermore, the partition has a mounting hole in the middle that is fitted onto the locking screw, and at least two positioning holes are provided on one side of the mounting hole. The fixing nut passes through the positioning holes and is fixed in the threaded hole of the magnetic pole assembly.

[0017] The spacer is precisely fitted into the locking screw through the central mounting hole to achieve axial positioning. The array of positioning holes on its side and the fixing nut form a multi-directional locking mechanism. When the fixing nut passes through the positioning hole and is screwed into the threaded hole of the magnetic pole assembly body, the circumferential and angular positioning accuracy of the spacer and the magnetic pole assembly is ensured.

[0018] Furthermore, the diaphragm is teardrop-shaped, with the part furthest from the outer ring of the rotor yoke being the tail end of the diaphragm. The upper and lower edges of the tail end of the diaphragm are respectively an upper arc surface and a lower arc surface. The upper and lower arc surfaces are brought together at one end, making the tail end of the diaphragm conical.

[0019] The baffle adopts a teardrop-shaped profile design that conforms to fluid dynamics. Its tail end, which is away from the rotor yoke, forms an aerodynamic conical structure through the asymptotic convergence of the upper and lower arc surfaces. When the rotor rotates at high speed, the tail end of the baffle can effectively guide the cooling airflow to pass smoothly along the gap of the magnetic pole assembly, which not only optimizes the heat dissipation efficiency but also improves the dynamic balance quality of the rotor system.

[0020] Furthermore, the tail end of the septum does not extend beyond the outer edge surface of the magnetic pole assembly.

[0021] The tail end of the septum adopts a sunken structure design, and the highest point of its conical profile is always controlled within the projection range of the outer edge surface of the magnetic pole. This strict height control not only ensures that the airflow boundary layer at the outer edge of the magnetic pole is not disturbed when the rotor rotates, but also avoids the potential interference risk between the tail end of the septum and the stator components.

[0022] Furthermore, the skewed pole unit is composed of N types of magnetic pole components. From the outside to the inside, the outermost magnetic pole component is the upright magnetic pole component N, the upright magnetic pole component N-1, the upright magnetic pole component N-2, and so on, followed by the reversed magnetic pole component N-1, the reversed magnetic pole component N-2, and so on, until the overall V-shaped skewed pole unit is finally assembled axially.

[0023] The slanted pole unit adopts a modular magnetic pole assembly arrangement design. From the outside to the inside, the positively mounted magnetic pole assemblies N, N-1, etc. are alternately combined with the reverse-mounted magnetic pole assemblies 1, 2, etc., forming an overall V-shaped topology through axial precision assembly. This layout not only ensures the continuity of the magnetic field generation system, but also optimizes the air gap magnetic field distribution through the synergistic effect of the positive and reverse-mounted magnetic pole assemblies. At the same time, the modular assembly method significantly improves production and maintenance efficiency. Its axially extended V-groove structure achieves comprehensive optimization of electromagnetic performance and heat dissipation characteristics while ensuring mechanical strength.

[0024] Furthermore, the magnetic pole group is divided into magnetic pole group one and magnetic pole group two. Both magnetic pole group one and magnetic pole group two include magnetic pole base one and magnetic pole base two that are in contact with the rotor yoke. Magnetic pole mounting box one and magnetic pole mounting box two are respectively located above magnetic pole base one and magnetic pole base two.

[0025] The centerline of magnetic pole mounting box one forms an angle α with the centerline of magnetic pole base one, and the centerline of magnetic pole mounting box two forms an angle β with the centerline of magnetic pole base two.

[0026] Magnets are inserted into magnetic pole mounting boxes one and two.

[0027] The first and second magnetic pole groups form a stable contact surface with the rotor yoke through their respective magnetic pole bases. The magnetic pole mounting boxes set above the two magnetic pole bases achieve an asymmetrical spatial layout through preset angles α and β. This staggered mounting structure not only provides bidirectional positioning slots for the magnets, but also optimizes the uniformity of the magnetic field distribution through the torque compensation effect formed by the angle. While ensuring the magnetic circuit closure efficiency, it effectively suppresses the risk of magnet displacement caused by centrifugal force during high-speed rotation.

[0028] Furthermore, the included angle β is greater than the included angle α.

[0029] The angle β formed between the center line of the magnetic pole mounting box 2 of magnetic pole group 2 and the magnetic pole base 2 is larger than the angle α formed between the magnetic pole mounting box 1 and the magnetic pole base 1 of magnetic pole group 1. When used together, it is easy to form an overall V-shaped magnetic pole structure.

[0030] By means of the above-described solution, the present invention has at least the following advantages:

[0031] 1. The use of axially V-shaped magnetic pole groups to replace the traditional stator skew slots eliminates the cogging torque fluctuations while avoiding the difficulties of embedding and unilateral axial force in the skew slot process, thus greatly improving manufacturing efficiency and extending bearing life.

[0032] 2. Precise circumferential positioning is achieved through the precise cooperation between the positioning guide bar and the guide groove of the magnetic pole assembly. Combined with the bidirectional limiting mechanism of the baffle and the triple constraint mechanism of the locking screw, the magnetic pole assembly maintains structural integrity under ultra-high centrifugal force.

[0033] 3. By utilizing the directional airflow channel constructed with teardrop-shaped partitions and the differentiated angled magnetic pole group, heat dissipation efficiency and magnetic field uniformity are optimized simultaneously, enabling the motor to have both high torque output stability and low electromagnetic interference characteristics.

[0034] The above description is merely an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention and to implement it in accordance with the contents of the specification, the preferred embodiments of the present invention are described in detail below with reference to the accompanying drawings. Attached Figure Description

[0035] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show a certain embodiment of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0036] Figure 1 This is a schematic diagram of the structure of the present invention;

[0037] Figure 2 This is the front view of the present invention;

[0038] Figure 3 This is the invention Figure 2 A magnified view of region B in the middle;

[0039] Figure 4 This is a schematic diagram of the slant pole unit of the present invention;

[0040] Figure 5 This is a schematic diagram of the "V"-shaped groove formed between the slanted pole units of the present invention;

[0041] Figure 6 This is the invention Figure 1 Enlarged view of region A in the middle;

[0042] Figure 7 This is a schematic diagram of the assembly of the first baffle of the present invention;

[0043] Figure 8 This is a schematic diagram of the assembly of the second baffle of the present invention;

[0044] Figure 9 This is a schematic diagram of the structure of the spacer of the present invention;

[0045] Figure 10 This is a schematic diagram of the assembly of the spacer of the present invention;

[0046] Figure 11 This is a schematic diagram of the structure of the first magnetic pole assembly of the present invention;

[0047] Figure 12 This is a schematic diagram of the structure of the second magnetic pole assembly of the present invention.

[0048] In the diagram: 1. Rotor yoke; 2. Inclined pole unit; 3. Pole assembly; 4. Magnet; 5. Pole group; 6. "V" groove; 7. Positioning groove; 8. Positioning strip; 9. Positioning guide strip; 10. Guide groove; 11. First baffle; 12. Second baffle; 13. Locking screw; 14. Locking nut; 15. Retaining ring; 16. Spacer; 17. Gap; 18. Vent groove; 19. Mounting hole; 20. Positioning hole; 21. Fixing nut; 22. Threaded hole; 23. Spacer tail end; 24. Upper arc surface; 25. Lower arc surface; 5-1. Pole group one; 5-2. Pole group two; 5-3. Pole base one; 5-4. Pole base two; 5-5. Pole mounting box one; 5-6. Pole mounting box two.

[0049] CL, the center line of magnetic pole base one and magnetic pole base two; BL, the center line of magnetic pole mounting box one and magnetic pole mounting box two. Detailed Implementation

[0050] The specific embodiments of the present invention will be described in further detail below with reference to the accompanying drawings and examples. The following examples are for illustrative purposes only and are not intended to limit the scope of the invention.

[0051] See Figures 1-4 The rotor yoke 1 serves as the core support structure. Its outer surface is constructed with uniformly arranged skewed pole units 2 to form a magnetic field generating system. Each skewed pole unit 2 is modularly assembled from several independent magnetic pole components 3. Magnets 4 are embedded inside the magnetic pole components 3 as excitation sources. Several magnetic pole components 3 are paired to form magnetic pole groups 5. Multiple magnetic pole groups 5 extend along the axial direction of the rotor yoke 1 and are arranged in a staggered manner at a specific angle, ultimately forming a continuous "V"-shaped groove structure 6 [see...]. Figure 5 [The slotted structure in the double dashed section] This innovative design, through the V-shaped topology layout of the modular skewed pole unit 2, optimizes the magnetic field waveform while ensuring the strength of the mechanical structure. It avoids the problem of axial unilateral magnetic pull caused by the traditional stator skewed slot, and effectively suppresses the cogging torque fluctuation through the synergistic effect of the multi-pole assembly 3. Combined with the symmetrical distribution characteristics of the pole group 5, it significantly improves the stability of the motor torque output.

[0052] See Figure 6 The outer surface of the rotor yoke 1 is precision-machined with multiple axial positioning grooves 7. High-strength positioning strips 8 are embedded within the positioning grooves 7 as a basic support structure. Screw holes are provided at the bottom of the positioning strips 8, and through holes that mate with the screw holes are located in the positioning grooves 7. Bolts are used to tighten and fix the positioning strips 8 into the positioning grooves 7. The top two sides of the positioning strips 8 extend outwards to form symmetrically distributed positioning guide strips 9, which form a precise sliding fit with the precision-machined guide grooves 10 on both sides of the magnetic pole assembly 3. When assembling the magnetic pole assembly 3, the guide grooves 10 on both sides of the magnetic pole assembly 3 are aligned with the positioning guide strips 9, and the assembly is slidably assembled. After assembly, a set of inclined pole units 2 are formed. This innovative positioning system ensures axial alignment through the rigid interlocking of positioning groove 7 and positioning bar 8. The dovetail-like fit between positioning guide bar 9 and guide groove 10 achieves precise circumferential positioning and radial force support for magnetic pole assembly 3. This not only solves the problem of insufficient positioning accuracy caused by traditional bolt fixing, but also greatly improves production efficiency through modular assembly design. At the same time, the full circumferential contact characteristics of positioning guide bar 9 effectively disperse centrifugal load, enabling magnetic pole assembly 3 to maintain structural stability under high-speed rotation conditions, providing a reliable mechanical fixing solution for large wind turbine rotors.

[0053] See Figure 7 and Figure 8 The device employs a bidirectional closed limiting structure composed of a first baffle 11 and a second baffle 12. By fixing the first baffle 11 and the second baffle 12 to the two ends of adjacent positioning strips 8 to form a rigid frame, the inner working surfaces of the first baffle 11 and the second baffle 12 form a surface contact constraint mechanism with the outer surfaces of the magnetic pole assemblies 3 at both ends of the inclined pole unit 2. When the rotor rotates at high speed, the first baffle 11 and the second baffle 12 respectively mechanically limit the magnetic pole assembly 3 from both axial sides to prevent the magnetic pole group 5 from axially moving due to centrifugal force. The tight fit between the inner walls of the first baffle 11 and the second baffle 12 and the magnetic pole assembly 3 can compensate for the assembly gap generated during assembly, ensuring positioning stability under different speed conditions. The modular first baffle 11 and the second baffle 12 are integrated with the positioning strips 8.

[0054] See Figure 6The magnetic pole assembly 3 is pierced by a high-strength locking screw 13 through a central through hole, and locking nuts 14 are fitted at both ends to form an axial locking system. The end face of the locking nut 14 is in rigid contact with the outer walls of the first baffle 11 and the second baffle 12 to transmit the locking force. The arc-shaped contour surfaces of the lower edges of the first baffle 11 and the second baffle 12 fit seamlessly with the outer circle of the rotor yoke 1 to achieve radial constraint. At the same time, the outer plane of the first baffle 11 forms circumferential positioning with the inner wall of the protruding retaining ring 15 on the outer edge of the rotor yoke 1. Through the axial tension of the locking screw 13, the radial support of the first baffle 11 and the second baffle 12, and the circumferential limiting effect of the retaining ring 15, the zero displacement stability of the magnetic pole assembly 3 is ensured under high-speed rotation conditions. The modular assembly design also enables rapid maintenance and replacement of the magnetic pole assembly 3, completely solving the maintenance difficulties caused by traditional welding processes.

[0055] See Figure 6 The slanted pole unit 2 adopts an innovative air gap heat dissipation architecture. By setting a spacer 16 with a locking screw 13 between adjacent magnetic pole components 3, a standardized gap 17 is precisely controlled to form an axial airflow channel. At the same time, corresponding ventilation grooves 18 are opened on the circumferential surface of the rotor yoke 1 for each gap 17, forming a double-layer ventilation circuit that runs through the magnetic pole group 5. This design breaks through the limitations of mechanical positioning and heat dissipation: while ensuring the spacing accuracy of the magnetic pole components 3, the spacer 16 optimizes the laminar flow characteristics of the airflow in the gap 17 with its guiding edges; the "vertical-horizontal" cross air channel formed by the ventilation grooves 18 and the gap 17 allows the cooling airflow to penetrate the solid structure of the rotor yoke 1 to achieve three-dimensional heat dissipation, which improves the heat dissipation efficiency by 40% compared with the traditional surface cooling method. It not only effectively reduces the working temperature of the magnet 4, but also actively suppresses specific order electromagnetic noise at the airflow whistling frequency generated by the gap 17, thus combining temperature rise control and acoustic optimization.

[0056] See Figure 9 and Figure 10 The mounting hole 19 of the partition 16 and the locking screw 13 form the main positioning channel. The positioning hole 20 of the partition 16 and the fixing nut 21 constitute an anti-rotation pair positioning mechanism. When the fixing nut 21 is screwed into the threaded hole 22 of the magnetic pole assembly 3, a constraint system of "axial sliding + circumferential locking" is formed to ensure the stable installation of the partition 16. The symmetrical layout of multiple positioning holes 20 allows the partition 16 to select different angle positioning holes 20 for installation according to the change of the oblique pole angle of the magnetic pole assembly 3, so that the partition 16 forms different tilt angles and ensures the uniformity of airflow in the gap 17 under different assembly modes.

[0057] See Figure 9The tail end 23 of the partition adopts a teardrop-shaped aerodynamic design, with its upper arc surface 24 and lower arc surface 25 gradually converging to form a conical tail structure that conforms to fluid dynamics. When the rotor rotates at high speed, the tail end 23 of the partition effectively guides the cooling airflow to form a wall-attached jet along the upper arc surface 24, enhancing the scouring effect on the side of the magnetic pole assembly 3. The curvature of the lower arc surface 25 can generate low-pressure vortices, which can increase the overall heat dissipation efficiency of the rotor. The airflow formed by the vent groove 18 generates a resonant acceleration effect. The asymmetrical shape of the double arc surface can directionally deflect the electromagnetic noise propagation path, and together with the main structure of the partition 16, they form an acoustic barrier.

[0058] By strictly controlling the height difference between the tail end 23 of the partition and the outer edge surface of the magnetic pole assembly 3, a stepped aerodynamic protection structure is constructed: when the rotor rotates at high speed, the deliberately lowered tail end 23 of the partition makes the outer edge of the magnetic pole assembly 3 form a natural flow guide lip, which can suppress the turbulent diffusion generated by the vent groove 18 and provide a directional acceleration channel for the cooling airflow guided by the upper arc surface 24. The outer edge of the magnetic pole assembly 3 provides a physical protection zone for the partition 16 assembly, reducing the risk of damage from foreign object impact.

[0059] See Figure 3 The skewed pole unit 2 achieves an innovative V-shaped topology through a carefully designed arrangement of progressively changing magnetic pole components 3. It is axially mirrored by alternating combinations of positive magnetic pole components 3 (N groups), (N-1 groups), etc., with reverse magnetic pole components 3 (N-1 groups), reverse magnetic pole components 3 (N groups), etc., from the outside to the inside. This unique layout not only ensures the continuity and stability of the magnetic field generation system, but also significantly optimizes the air gap magnetic field waveform through the synergistic effect of positive and reverse magnetic poles, greatly reducing torque pulsation and improving electromagnetic efficiency. At the same time, the modular assembly design gives it excellent production flexibility and maintenance convenience. The V-shaped structure strengthens the overall mechanical integrity while cleverly balancing electromagnetic performance and heat dissipation requirements. This allows the skewed pole unit 2 to have excellent vibration suppression capability and temperature rise control performance under high-speed operation conditions, providing a highly reliable and efficient magnetic field solution for rotating electric motor systems.

[0060] See Figure 11 and Figure 12 The overall structure of magnetic pole group 1 5-1 and magnetic pole group 2 5-2 is basically the same. The difference lies in the deflection angle of the upper magnetic pole mounting box 1 5-5 and magnetic pole mounting box 2 5-6. The center line of magnetic pole mounting box 1 5-5 forms an angle α with the center line of magnetic pole base 1 5-3, and the center line of magnetic pole mounting box 2 5-6 forms an angle β with the center line of magnetic pole base 2 5-4. Magnetic pole mounting box 1 5-5 and magnetic pole mounting box 2 5-6 form angles with the center lines of the corresponding magnetic pole base 1 5-3 and magnetic pole base 2 5-4 with angles α and β, respectively. The installation angle of the corresponding magnetic pole component 3 is optimized, and finally the required oblique pole unit 2 with "V" shaped groove 6 is formed.

[0061] Angle β being greater than angle α is used to distinguish between the corresponding magnetic pole group 2 5-2 and magnetic pole group 1 5-1, making it easier to select the corresponding magnetic pole assembly 3 for installation.

[0062] The working principle of this invention is as follows:

[0063] The magnetic pole group 5 constructs the skewed pole unit 2 through the combination of magnetic pole group one 5-1 and magnetic pole group two 5-2. Magnetic pole group one 5-1 includes magnetic pole base one 5-3 and magnetic pole mounting box one 5-5 above it. Magnetic pole group two 5-2 includes magnetic pole base two 5-4 and magnetic pole mounting box two 5-6 above it. The center line of magnetic pole mounting box one 5-5 forms an angle α with the center line of magnetic pole base one 5-3, and the center line of magnetic pole mounting box two 5-6 forms an angle β with the center line of magnetic pole base two 5-4. The magnet 4 is inserted into magnetic pole mounting box one 5-5 and magnetic pole mounting box two 5-6. The axial positioning groove 7 on the outer surface of the rotor yoke 1 is fitted with a positioning strip 8 with positioning guide strip 9. The guide grooves 10 on both sides of the magnetic pole assembly 3 slide with the positioning guide strip 9 to form the modular skewed pole unit 2. The locking screw 13 passes through the through hole in the middle of the magnetic pole assembly 3 and is locked at both ends by locking nuts 14. The first baffle 11 and the second baffle 12 at both ends are open. The inner working surface constrains the axial displacement of the magnetic pole assembly 3, and its lower edge arc contour surface fits the outer circle of the rotor yoke 1. The outer plane of the first baffle 11 and the inner wall of the retaining ring 15 form circumferential positioning. A spacer 16 fitted with a locking screw 13 is set between adjacent magnetic pole assemblies 3 to form a standardized gap 17. It works with the ventilation groove 18 of the rotor yoke 1 to form a double-layer heat dissipation air duct. The mounting hole 19 of the spacer 16 cooperates with the locking screw 13. The positioning hole 20 on the spacer 16 is locked with the threaded hole 22 of the magnetic pole assembly 3 by the fixing nut 21 to prevent rotation. The upper arc surface 24 and the lower arc surface 25 of the teardrop-shaped spacer tail end 23 form a conical tail fin to guide the airflow. The height of the spacer tail end 23 does not exceed the outer edge of the magnetic pole assembly 3 to construct a stepped aerodynamic protection. Multiple sets of magnetic pole groups 5 are arranged at an angle along the axial direction of the rotor yoke 1 to form a continuous "V" shaped groove 6, realizing magnetic field waveform optimization and stable torque output.

[0064] Generally, magnet 4 is made of hard magnetic materials such as ferrite and neodymium iron boron; magnetic pole mounting box 1 5-5 and magnetic pole mounting box 2 5-6 are usually made of silicon steel sheets of the same shape that are stamped or laser-cut and then stacked together.

[0065] Different magnetic pole assemblies 3 all have the same outer convex pole part, i.e., magnetic pole mounting box and inner circle part, i.e. magnetic pole base. The center of the outer arc surface of the outer convex pole part is on the central symmetry line of the inner circle part. The center alignment mechanism promotes precise matching of the magnetic center lines of the stator and rotor, effectively suppresses the axial movement caused by the axial magnetic pull, and ensures the structural stability under high-speed rotation. The main difference in shape between different magnetic pole assemblies 3 is that the included angle between the central symmetry line of the outer convex pole part and the central symmetry line of the inner circle part is different.

[0066] To suppress cogging torque, a specific skew angle value must first be determined. The skew angle C is usually preferably the circumferential angle corresponding to one slot pitch, which is 360 degrees divided by the total number of stator slots.

[0067] Assuming there are N types of magnetic pole components 3 (i.e., there are N types of angles between the central symmetry lines of the outer convex pole portion and the central symmetry lines of the inner convex pole portion), then the angle of magnetic pole group 1 5-1 is C / (4N), the angle of magnetic pole group 2 5-2 is 3C / (4N), the angle of magnetic pole 3 is 5C / (4N)... and the angle of magnetic pole a is (2a-1)C / (4N), where a is the serial number and the value range is 1, 2, 3...N.

[0068] When each skewed pole unit 2 is arranged, the total number of magnetic pole components 3 is usually more than that of magnetic pole groups 5, so they need to be arranged in groups. By arranging different groups of magnetic pole groups 5 and the combinations of positive and negative assembly [the outermost is the positively assembled magnetic pole component 3 (N group), the innermost are the positively assembled magnetic pole component 3 (N-1 group), the positively assembled magnetic pole component 3 (N-2 group) ... the negatively assembled magnetic pole component 3 (N-2 group), the negatively assembled magnetic pole component 3 (N-1 group) ... the negatively assembled magnetic pole component 3 (N group)], the overall V-shaped skewed pole unit 2 can be axially assembled.

[0069] With the number of magnetic pole groups as two, the magnetic pole assembly 3 consists of two magnetic pole groups 1 5-1 and magnetic pole group 2 5-2. The total number of blocks in the magnetic pole assembly 3 is fourteen. The outermost part of the oblique pole unit 2 consists of two positively mounted magnetic pole groups 2 5-2. Moving inward, there are positively mounted magnetic pole group 1 5-1, reverse-mounted magnetic pole group 1 5-1, and reverse-mounted magnetic pole group 2 5-2 in the middle position.

[0070] When assembling this rotor, first place the positioning strip 8 in the positioning groove 7 and lock and fix the positioning strip 8 with bolts. Then, select the corresponding number of magnetic pole group 1 5-1 and magnetic pole group 2 5-2 according to the requirements, and slide them into the positioning strip 8 in sequence. Before this, spacers 16 need to be installed on the corresponding magnetic pole components 3. During assembly, ensure that there is a spacer 16 between the two magnetic pole components 3. After the magnetic pole components 3 are installed, the corresponding skewed pole unit 2 can be formed. The first baffle 11 and the second baffle 12 are placed at both ends of the skewed pole unit 2. The locking screw 13 passes through the entire skewed pole unit 2, and the locking nut 14 provides a certain axial preload to the skewed pole unit 2. Finally, fix it to both ends of the positioning strip 8 with bolts to complete the fixed installation of the skewed pole unit 2.

[0071] Finally, the following points should be noted: First, in the description of this application, it should be noted that, unless otherwise specified and limited, the terms "installation", "connection", and "linkage" should be interpreted broadly, and can be mechanical or electrical connections, or internal connections between two components, or direct connections. "Up", "down", "left", "right", etc. are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may change.

[0072] Secondly: The accompanying drawings of the embodiments disclosed in this invention only involve the structures involved in the embodiments disclosed in this invention. Other structures can refer to the general design. In the absence of conflict, the same embodiment and different embodiments of this invention can be combined with each other.

[0073] Finally: The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A permanent magnet electric machine rotor comprising a rotor yoke (1), characterized in that: The outer surface of the rotor yoke (1) is uniformly and spacedly arranged with inclined pole units (2), the inclined pole units (2) are composed of a plurality of magnetic pole assemblies (3), each magnetic pole assembly (3) is embedded with a magnetic steel (4), a plurality of magnetic pole assemblies (3) form a magnetic pole group (5), and a plurality of magnetic pole groups (5) form a "V"-shaped slot (6) on the outer surface of the rotor yoke (1) in the axial direction; The outer surface of the rotor yoke (1) is provided with a plurality of axially arranged positioning grooves (7), the positioning grooves (7) are fixedly provided with positioning strips (8), the upper ends of the positioning strips (8) extend outward on both sides to form positioning guide strips (9), and the two sides of the magnetic pole assembly (3) are provided with guide grooves (10) matched with the positioning guide strips (9); The two ends of every two adjacent positioning strips (8) are respectively fixedly provided with first baffles (11) and second baffles (12), the inner side walls of the first baffles (11) and the second baffles (12) are in contact with the magnetic pole assemblies (3) at the two ends of the inclined pole unit (2), thereby providing outer end limiting for the magnetic pole assemblies (3); The middle part of each magnetic pole assembly (3) is provided with a through hole, a locking screw (13) is arranged in the through hole, the two ends of the locking screw (13) are screwed into locking nuts (14), the locking nuts (14) are in contact with the outer walls of the corresponding first baffles (11) and the second baffles (12), the lower arc surface of the first baffles (11) and the second baffles (12) is in contact with the outer surface of the rotor yoke (1), and the outer surface of the first baffle (11) is in contact with the inner wall of the baffle ring (15) protruding outward along the outer edge of the rotor yoke (1); The two adjacent magnetic pole assemblies (3) in the inclined pole unit (2) are provided with a spacer (16) sleeved on the locking screw (13), the spacer (16) is used for separating the two magnetic pole assemblies (3) to form a gap (17) between the magnetic pole assemblies (3), and the rotor yoke (1) is provided with a ventilation groove (18) corresponding to each gap (17) below the gap (17) on the circumference; The middle part of the spacer (16) is provided with a mounting hole (19) sleeved on the locking screw (13), at least two positioning holes (20) are formed in one side of the mounting hole (19), and a fixing nut (21) is fixed in a threaded hole (22) of the magnetic pole assembly (3) after penetrating through the positioning hole (20); The spacer (16) is in the shape of a water droplet, the part away from the outer circle of the rotor yoke (1) is a spacer tail end (23), the upper edge and the lower edge of the spacer tail end (23) are respectively an upper arc surface (24) and a lower arc surface (25), and one end of the upper arc surface (24) and the lower arc surface (25) is gathered and fitted, so that the spacer tail end (23) is in the shape of a cone.

2. A permanent magnet machine rotor according to claim 1, characterized in that: The spacer tail end (23) does not exceed the outer edge surface of the magnetic pole assembly (3).

3. A method of arranging skew-pole units of a rotor of a permanent-magnet electric machine according to claim 1 or 2, characterized in that: The inclined pole unit (2) is composed of N magnetic pole assemblies (3), the outermost magnetic pole assembly (3) from the outside to the inside is a positive magnetic pole assembly (3) N, a positive magnetic pole assembly (3) N-1, a positive magnetic pole assembly (3) N-2, a negative magnetic pole assembly (3) N-2, a negative magnetic pole assembly (3) N-1, and a negative magnetic pole assembly (3) N, and finally the whole V-shaped inclined pole unit (2) is assembled in the axial direction.

4. A method of arranging the skew pole units of a permanent magnet motor rotor according to claim 3, characterized in that: When the magnetic pole group (5) is composed of the first magnetic pole group (5-1) and the second magnetic pole group (5-2), the first magnetic pole group (5-1) and the second magnetic pole group (5-2) both include the first magnetic pole base (5-3) and the second magnetic pole base (5-4) which are attached to the rotor yoke (1), and the first magnetic pole base (5-3) and the second magnetic pole base (5-4) are respectively provided with the first magnetic pole mounting box (5-5) and the second magnetic pole mounting box (5-6) above; The center line of the first magnetic pole mounting box (5-5) and the center line of the first magnetic pole base (5-3) form an angle α, and the center line of the second magnetic pole mounting box (5-6) and the center line of the second magnetic pole base (5-4) form an angle β; The magnetic pole mounting box (5-5) and the magnetic pole mounting box (5-6) are clamped with the magnetic steel (4) inside; The angle β is greater than the angle α.

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