Permanent magnet motor rotor and skewed pole unit arrangement method thereof

Abstract

The invention relates to the technical field of large wind driven generator permanent magnet motors, in particular to a permanent magnet motor rotor and a skewed pole unit arrangement method thereof. Oblique pole units are evenly distributed on the outer surface of a rotor magnet yoke at intervals, each oblique pole unit is composed of a plurality of magnetic pole assemblies, magnetic steel is embedded in each magnetic pole assembly, a plurality of magnetic pole assemblies form a magnetic pole set, and a plurality of magnetic pole sets axially form a V-shaped groove in the outer surface of the rotor magnet yoke. The core component of the permanent magnet motor rotor is an annular rotor magnet yoke, the outer circumferential surface of the annular rotor magnet yoke adopts regularly arranged skewed pole units to form a magnetic field generation structure, each skewed pole unit is formed by combining a plurality of independent magnetic pole assemblies, permanent magnets are embedded in the magnetic pole assemblies to provide an excitation source, and the plurality of magnetic pole assemblies are paired to form a magnetic pole group. The multiple magnetic pole assemblies are arranged on the surface of the rotor magnet yoke in an extending mode in the axial direction and staggered at a specific angle to form a continuous V-shaped groove structure, and by means of the design, magnetic field distribution optimization is achieved, and integrity of mechanical strength is guaranteed.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of large wind turbine permanent magnet motor, in particular to a permanent magnet motor rotor and a skew pole unit arrangement method thereof. BACKGROUND

[0002] In the operation of the motor, due to the existence of the core tooth slot, the motor will generate a tooth slot torque when rotating, which becomes one of the reasons causing torque fluctuation. At present, the permanent magnet synchronous motor used in the market, especially the half-direct-drive wind turbine, generally adopts the combination scheme of stator skew slot and rotor non-skew pole to weaken the specific harmonic, thereby effectively weakening the tooth slot torque and improving the operation characteristics of the motor. However, because the outer diameter of the wind turbine is relatively large, the rotor magnetic poles are uniformly divided into blocks in the circumferential direction and are uniformly divided into blocks in the axial direction, and the rotor magnetic poles are assembled with strong magnetism, the stator skew slot method brings inconvenience to manufacturing and wire embedding, the working efficiency is low, and the skew slot only tilts in one direction, which affects the balance of the stator and the rotor and causes certain influence on the bearing.

[0003] In addition, with the increasing of the speed and diameter of the rotor of the half-direct-drive generator of the wind turbine, the centrifugal force also increases sharply. In this case, how to reliably and effectively fix the magnetic pole assembly on the rotor yoke under the action of large centrifugal force becomes a key problem.

[0004] In view of the above defects, the present design person actively researches and innovates to create a permanent magnet motor rotor and a skew pole unit arrangement method, so that it has more industrial utilization value. SUMMARY

[0005] To solve the above technical problems, the purpose of the present application is to provide a permanent magnet motor rotor and a skew pole unit arrangement method.

[0006] The permanent magnet motor rotor of the present application comprises a rotor yoke, skew pole units are uniformly and spaced arranged on the outer surface of the rotor yoke, the skew pole units are composed of a plurality of 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 a plurality of magnetic pole groups form a V-shaped groove in the axial direction on the outer surface of the rotor yoke.

[0007] The core component of the permanent magnet motor rotor is an annular rotor yoke, the outer circumferential surface of which is composed of regularly arranged skew pole units to form a magnetic field generating structure, each skew pole unit is composed of a plurality of independent magnetic pole assembly modules, a permanent magnet is embedded in the magnetic pole assembly to provide an excitation source, a plurality of magnetic pole assemblies are paired to form a magnetic pole group, and a plurality of magnetic pole assemblies are arranged in the axial direction on the surface of the rotor yoke to form a continuous V-shaped groove structure through specific angle staggering. This design not only optimizes the magnetic field distribution, but also ensures the integrity of the mechanical strength.

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

[0009] The outer circumferential surface of the rotor yoke is machined with several axially extending positioning grooves, and rigid positioning strips are embedded in the grooves as the basic guiding structure. The positioning guide bars on the top of the positioning strips form a stable double-wing support interface. Guide grooves matching the geometric profile of the positioning guide bars are precisely machined on both sides of the magnetic pole assembly. The magnetic pole group is accurately positioned in the circumferential direction and supported in the radial direction by sliding engagement.

[0010] Furthermore, a first baffle and a second baffle are fixed to both ends of every two adjacent positioning bars respectively, and the inner side walls of the first baffle and the second baffle are in contact with the magnetic pole assemblies at both ends of the oblique pole unit to provide outer end limit for the magnetic pole assemblies.

[0011] The first baffle and the second baffle respectively assembled at the two ends of adjacent positioning bars form a closed limiting structure, wherein the inner working surfaces of the first baffle and the second baffle are tightly fitted with the outer surfaces of the magnetic pole assemblies at both ends of the skew pole unit, forming a bidirectional mechanical constraint on the magnetic pole assemblies. This design not only ensures the precise positioning of the magnetic pole assemblies in the circumferential direction of the rotor, but also achieves bidirectional blocking of axial displacement through direct contact between the baffle and the magnetic pole assembly, 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, a locking screw passes through the through hole, and locking nuts are screwed into both ends of the locking screw. The locking nuts are in contact with the outer walls of the corresponding first baffle and second baffle. The arc-shaped surfaces at the lower edges of the first baffle and the second baffle 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 raised retaining ring on the outer edge of the rotor yoke.

[0013] The central through hole of the magnetic pole assembly passes through a high-strength locking screw, and its two ends are axially locked by locking nuts. The end faces of the locking nuts form rigid contact with the outer planes of the first baffle and the second baffle. At the same time, the arc-shaped contour surface of the lower edge of the baffle maintains seamless fit with the outer circle of the rotor yoke, and the outer positioning surface of the first baffle is tightly matched 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 circumferential, axial and radial directions of the rotor through the triple synergistic effect of the axial preload of the screw, the radial fitting 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] Further, the spacer is sleeved on the locking screw between two adjacent magnetic pole assemblies in the inclined pole unit, and the spacer is used to separate the two magnetic pole assemblies to have a gap between the magnetic pole assemblies.

[0015] The spacer is precisely sleeved on the locking screw penetrating the magnetic pole assembly to form a physical isolation layer, so that a constant gap space is maintained between the adjacent magnetic pole assemblies, and the gap and the corresponding air passage groove on the circumferential surface of the rotor yoke form a continuous ventilation path.

[0016] Further, the spacer has a mounting hole sleeved on the locking screw in the middle part, and at least two positioning holes are formed on one side of the mounting hole.

[0017] The spacer is precisely sleeved on the locking screw to realize axial positioning, and the array type positioning holes formed on the side of the spacer form a multidirectional locking mechanism with the fixing nut.

[0018] Further, the spacer has a mounting hole sleeved on the locking screw in the middle part, and at least two positioning holes are formed on one side of the mounting hole.

[0019] The spacer adopts a water droplet-shaped profile design in accordance with fluid mechanics, and the tail end of the spacer away from the rotor yoke forms an aerodynamic conical structure through the gradual convergence of the upper arc surface and the lower arc surface.

[0020] Further, the spacer tail end does not exceed the outer edge surface of the magnetic pole assembly.

[0021] The spacer tail end adopts a sunken structure design, and the highest point of the conical profile is always controlled within the projection range of the magnetic pole outer edge surface.

[0022] Further, the inclined pole unit is composed of N kinds of magnetic pole assemblies, and the magnetic pole assemblies are arranged from outside to inside as positive magnetic pole assembly N, positive magnetic pole assembly N-1, positive magnetic pole assembly N-2, negative magnetic pole assembly N-1, negative magnetic pole assembly N-2, and negative magnetic pole assembly N, and finally the whole V-shaped inclined pole unit is assembled axially.

[0023] The inclined pole unit adopts a gradient arrangement design of modular magnetic pole assemblies, and the modular magnetic pole assemblies are arranged from outside to inside as positive magnetic pole assembly N, positive magnetic pole assembly N-1, and negative magnetic pole assembly 1 group and negative magnetic pole assembly 2 group are alternately combined, and the whole V-shaped topology structure is formed through axial precise assembly, and the 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 positive and negative magnetic pole assemblies, and the modular assembly mode significantly improves the production and maintenance efficiency, and the axially extended V-shaped groove structure ensures the mechanical strength and realizes the comprehensive optimization of electromagnetic performance and heat dissipation characteristics.

[0024] Further, the magnetic pole assembly is composed of magnetic pole assembly one and magnetic pole assembly two, and the magnetic pole assembly one and the magnetic pole assembly two both include magnetic pole base one and magnetic pole base two which are attached to the rotor yoke, and above the magnetic pole base one and the magnetic pole base two are magnetic pole mounting box one and magnetic pole mounting box two respectively, The center line of the magnetic pole mounting box one and the center line of the magnetic pole base one form an angle alpha, and the center line of the magnetic pole mounting box two and the center line of the magnetic pole base two form an angle beta, The magnetic steel is clamped in the magnetic pole mounting box one and the magnetic pole mounting box two.

[0025] The magnetic pole assembly one and the magnetic pole assembly two form stable attachment surfaces with the rotor yoke through the magnetic pole bases, and the magnetic pole mounting boxes arranged above the two magnetic pole bases realize asymmetric spatial layout through the preset angles alpha and beta, and the staggered mounting structure not only provides a two-way positioning clamping groove for the magnetic steel, but also optimizes the magnetic field distribution uniformity through the torque compensation effect formed by the angles, and effectively suppresses the displacement risk of the magnetic steel caused by centrifugal force during high-speed rotation while ensuring the magnetic circuit closure efficiency.

[0026] Further, the angle beta is greater than the angle alpha.

[0027] The angle beta formed by the center line of the magnetic pole mounting box two of the magnetic pole assembly two and the magnetic pole base two has a larger angle value than the angle alpha formed by the magnetic pole mounting box one of the magnetic pole assembly one and the magnetic pole base one, and after combined use, a whole V-shaped magnetic pole structure is formed.

[0028] Through the above scheme, the present application has at least the following advantages: 1. The axial V-shaped distributed magnetic pole assembly replaces the traditional stator inclined slot, eliminates the tooth slot torque fluctuation, avoids the embedding difficulty of the inclined slot process and the single-sided axial force problem, greatly improves the manufacturing efficiency and prolongs the bearing life; 2. The precise circumferential positioning is realized by the precise cooperation of the positioning guide bar and the guide slot of the magnetic pole assembly, the double-directional limiting and locking screw triple-restriction mechanism cooperates with the baffle to ensure the structural integrity of the magnetic pole assembly under the ultra-high centrifugal force; 3. The directional air flow channel constructed by the water-drop-shaped partition and the differential-angle magnetic pole group are used to simultaneously optimize the heat dissipation efficiency and the magnetic field uniformity, so that the motor has high torque output stability and low electromagnetic interference characteristics.

[0029] The above description is only a summary of the technical solutions of the present application. In order to more clearly understand the technical means of the present application, and to implement the content of the description, the following will be described in detail with the preferred embodiments of the present application and in conjunction with the drawings. BRIEF DESCRIPTION OF DRAWINGS

[0030] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the embodiments. It should be understood that the following drawings only show some embodiments of the present application, and therefore should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can also be obtained without creative labor on the basis of these drawings.

[0031] Figure 1 is a structural schematic diagram of the present application; Figure 2 is a front view of the present application; Figure 3 is a structural schematic diagram of the present application; Figure 2 is a local enlargement of the B area in the present application; Figure 4 is a structural schematic diagram of the inclined pole unit of the present application; Figure 5 is a schematic diagram of the "V" type slot formed between the inclined pole units of the present application; Figure 6 is an enlarged schematic diagram of the A area in the present application; Figure 1 Figure 7 is a first baffle assembly schematic diagram of the present application; Figure 8 is a second baffle assembly schematic diagram of the present application; Figure 9 is a structural schematic diagram of the partition of the present application; Figure 10 is an assembly schematic diagram of the partition of the present application; Figure 11 is a structural schematic diagram of the first magnetic pole group of the present application; Figure 12 is a structural schematic diagram of the second magnetic pole group of the present application.

[0032] ​Figure 1, rotor yoke, 2, inclined pole unit, 3, magnetic pole assembly, 4, magnetic steel, 5, magnetic pole group, 6, "V" type slot, 7, positioning slot, 8, positioning bar, 9, positioning guide bar, 10, guide slot, 11, first baffle, 12, second baffle, 13, locking screw, 14, locking nut, 15, baffle ring, 16, spacer, 17, gap, 18, air groove, 19, mounting hole, 20, positioning hole, 21, fixing nut, 22, threaded hole, 23, spacer tail end, 24, upper circular surface, 25, lower circular surface, 5-1, magnetic pole group one, 5-2, magnetic pole group two, 5-3, magnetic pole base one, 5-4, magnetic pole base two, 5-5, magnetic pole mounting box one, 5-6, magnetic pole mounting box two.

[0033] CL, center line of magnetic pole base one and magnetic pole base two, BL, center line of magnetic pole mounting box one and magnetic pole mounting box two. DETAILED DESCRIPTION

[0034] The specific embodiments of the present application will be further described in detail below with reference to the accompanying drawings and examples. The following examples are used to illustrate the present application, but are not used to limit the scope of the present application.

[0035] Reference Figures 1-4 , the rotor yoke 1 as the core support structure, its outer surface through the uniform arrangement of inclined pole unit 2 to build magnetic field generation system, each inclined pole unit 2 by a number of independent magnetic pole assembly 3 modular combination, magnetic pole assembly 3 inside inlay magnetic steel 4 as excitation source, a number of magnetic pole assembly 3 pairing to form magnetic pole group 5, multiple magnetic pole group 5 along the rotor yoke 1 axial extension and staggered arrangement of a particular angle, eventually form a continuous "V" type slot 6 structure [see Figure 5 the slot structure of the double dotted line part in figure], this innovative design through the modular inclined pole unit 2 V type topology layout, while ensuring the mechanical strength of the structure, realize the optimization of magnetic field waveform, both avoid the problem of single side magnetic pull caused by the traditional stator skew slot, and effectively suppress the cogging torque fluctuation through the synergistic effect of multiple magnetic pole assembly 3, with the symmetrical distribution characteristics of magnetic pole group 5, significantly improve the stability of motor torque output.

[0036] Reference Figure 6, the outer surface of the rotor yoke 1 is precisely machined with multiple axial positioning grooves 7, the positioning grooves 7 are embedded with high-strength positioning strips 8 as the basic support structure, screw holes are opened at the bottom of the positioning strips 8, the positioning grooves 7 have through holes matched with the screw holes, the positioning strips 8 are tightly fixed in the positioning grooves 7 by bolts, the top of the positioning strips 8 extends outward to form symmetrically distributed positioning guide strips 9, which form a precise sliding fit with the guide grooves 10 precisely machined 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 connected with the positioning guide strips 9, and the assembly is completed in a sliding manner, forming a group of inclined pole units 2, the innovative positioning system ensures the axial centering through the rigid embedding of the positioning grooves 7 and the positioning strips 8, and realizes the circumferential precise positioning and radial force support of the magnetic pole assembly 3 through the dovetail type cooperation of the positioning guide strips 9 and the guide grooves 10, which not only solves the problem of insufficient positioning accuracy caused by traditional bolt fixing method, but also greatly improves the production efficiency through modular assembly design, and the full circumferential contact characteristics of the positioning guide strips 9 effectively disperse the centrifugal force load, so that the magnetic pole assembly 3 maintains structural stability under high-speed rotating conditions, providing a reliable mechanical fixing solution for large wind turbine rotors.

[0037] Referring to Figure 7 and Figure 8 , the bidirectional closed limiting structure composed of the first baffle 11 and the second baffle 12 is fixed on both ends of the adjacent positioning strips 8 to form a rigid frame, the inner side working surface of the first baffle 11 and the second baffle 12 forms a surface contact constraint mechanism with the outer surface of the magnetic pole assembly 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 implement mechanical limiting of the magnetic pole assembly 3 from both axial sides, preventing the magnetic pole group 5 from producing axial movement due to centrifugal force, the close-fitting characteristics of the inner side wall of the first baffle 11 and the second baffle 12 with the magnetic pole assembly 3 can compensate for the assembly gap generated during assembly, ensuring the positioning stability under different rotating speed conditions, and the integrated design of the modular first baffle 11 and the second baffle 12 with the positioning strip 8.

[0038] Referring to Figure 6, magnetic pole assembly 3 through the middle through hole through high strength locking screw 13, both ends of locking nut 14 form axial locking system, locking nut 14 end face and the outer wall of the first baffle 11, second baffle 12 rigid contact transmission locking force, the first baffle 11 and the second baffle 12 lower along the arc profile surface and the rotor yoke 1 outer circle seamless fit to realize radial constraint, at the same time, the outer side plane of the first baffle 11 and the inner wall of the rotor yoke 1 outer along the protruding ring 15 form the circumferential positioning, through the axial tension of locking screw 13, the radial support of the first baffle 11 and the second baffle 12 and the circumferential limit of the ring 15 synergistic effect, under the condition of high speed rotation, both ensure the zero displacement stability of the magnetic pole assembly 3, and realize the quick maintenance and replacement of the magnetic pole assembly 3 through the modular assembly design, completely solve the maintenance difficulty problem caused by traditional welding technology.

[0039] Referring to Figure 6 , inclined pole unit 2 adopts innovative air gap heat dissipation architecture, by setting the spacer 16 sleeved into the locking screw 13 between the adjacent magnetic pole assemblies 3, the standardized gap 17 is accurately controlled as the axial airflow channel, at the same time, the rotor yoke 1 circumferential surface is provided with corresponding air permeable grooves 18 for each gap 17, which constitutes a double-layer ventilation circuit through the magnetic pole group 5. This design innovatively integrates mechanical positioning and heat dissipation function: the spacer 16 not only ensures the spacing accuracy of the magnetic pole assembly 3, but also optimizes the laminar flow characteristics of the airflow in the gap 17; the "vertical-horizontal" cross air duct formed by the air permeable groove 18 and the gap 17 enables the cooling airflow to penetrate the rotor yoke 1 solid structure to realize three-dimensional heat dissipation, which improves the heat dissipation efficiency by 40% compared with the traditional surface cooling method, not only effectively reduces the working temperature of the magnetic steel 4, but also actively suppresses the specific order electromagnetic noise caused by the airflow whistling frequency of the gap 17, which has temperature rise control and acoustic optimization.

[0040] Referring to Figure 9 and Figure 10 , the mounting hole 19 of the spacer 16 and the locking screw 13 form the main positioning channel, the positioning hole 20 of the spacer 16 and the fixed nut 21 constitute the anti-rotation secondary positioning mechanism, when the fixed nut 21 is screwed into the threaded hole 22 of the magnetic pole assembly 3, the "axial sliding + circumferential locking" constraint system is formed, which ensures the stable installation of the spacer 16, the symmetrical layout of multiple positioning holes 20 enables the spacer 16 to select different angle positioning holes 20 for installation according to the inclined angle of the magnetic pole assembly 3, so that the spacer 16 forms different inclination angles, which guarantees the airflow uniformity of the gap 17 under different assembly modes.

[0041] Referring to Figure 9The tail end 23 of the partition piece is designed in a water-drop-shaped aerodynamic shape, and the upper circular arc surface 24 and the lower circular arc surface 25 are gradually gathered to form a conical tail structure in accordance with fluid dynamics. When the rotor rotates at high speed, the tail end 23 of the partition piece effectively guides the cooling airflow to form a wall jet along the upper circular arc surface 24, enhances the flushing effect on the side surface of the magnetic pole assembly 3, and the curvature of the lower circular arc surface 25 can generate a low-pressure vortex to increase the overall heat dissipation efficiency of the rotor. The airflow generated by the air-permeable groove 18 produces a resonant acceleration effect, and the asymmetric shape of the double circular arc surfaces can direct the propagation path of electromagnetic noise and form an acoustic barrier together with the main structure of the partition piece 16.

[0042] The height difference between the tail end 23 of the partition piece and the outer surface of the magnetic pole assembly 3 is strictly controlled to form a stepped aerodynamic protection structure. When the rotor rotates at high speed, the intentionally lowered tail end 23 of the partition piece forms a natural flow guide lip on the outer edge of the magnetic pole assembly 3, which can not only suppress the turbulent diffusion generated by the air-permeable groove 18, but also provide a directional acceleration channel for the cooling airflow guided by the upper circular arc surface 24. The outer edge of the magnetic pole assembly 3 provides physical protection for the partition piece 16 assembly, reducing the risk of foreign object impact damage.

[0043] Referring to Figure 3 , the inclined pole unit 2 realizes an innovative V-shaped topology structure through the arrangement of the gradient magnetic pole assembly 3. The V-shaped topology structure is formed by the axial mirror image of the positive magnetic pole assembly 3 (N groups), (N-1 groups), and the reverse magnetic pole assembly 3 (N-1 groups), and the reverse magnetic pole assembly 3 (N-2 groups) in turn from outside to 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 negative magnetic poles, greatly reduces torque ripple and improves electromagnetic efficiency. At the same time, the modular assembly design gives it excellent production flexibility and maintenance convenience. The V-shaped structure not only strengthens the mechanical integrity, but also balances the electromagnetic performance and heat dissipation demand, making the inclined pole unit 2 have excellent vibration suppression ability and temperature rise control performance under high-speed running conditions, providing a high-reliability and high-efficiency magnetic field solution for rotating motor systems.

[0044] Referring to Figure 11 and Figure 12 , the magnetic pole group one 5-1 and the magnetic pole group two 5-2 have basically the same overall structure, but the deflection angles of the magnetic pole mounting box one 5-5 and the magnetic pole mounting box two 5-6 are different. The center line of the magnetic pole mounting box one 5-5 and the center line of the magnetic pole base one 5-3 form an angle α, and the center line of the magnetic pole mounting box two 5-6 and the center line of the magnetic pole base two 5-4 form an angle β. The magnetic pole mounting box one 5-5 and the magnetic pole mounting box two 5-6 form angles with the center lines of the corresponding magnetic pole base one 5-3 and magnetic pole base two 5-4 at angles α and β respectively, which optimizes the installation angle of the corresponding magnetic pole assembly 3 and finally forms the inclined pole unit 2 with the required "V"-shaped slot 6.

[0045] The included angle β is greater than the included angle α, which is used to distinguish the corresponding magnetic pole group two 5-2 and the magnetic pole group one 5-1, so as to select the corresponding magnetic pole assembly 3 for installation.

[0046] The working principle of the application is as follows: The magnetic pole group 5 is constructed by the combination of the magnetic pole group one 5-1 and the magnetic pole group two 5-2, the magnetic pole group one 5-1 comprises the magnetic pole base one 5-3 and the magnetic pole mounting box one 5-5 above, the magnetic pole group two 5-2 comprises the magnetic pole base two 5-4 and the magnetic pole mounting box two 5-6 above, the center line of the magnetic pole mounting box one 5-5 and the center line of the magnetic pole base one 5-3 form an included angle α, the center line of the magnetic pole mounting box two 5-6 and the center line of the magnetic pole base two 5-4 form an included angle β, the magnetic steel 4 is clamped into the magnetic pole mounting box one 5-5 and the magnetic pole mounting box two 5-6; the positioning strip 8 with the positioning guide strip 9 is embedded in the axial positioning groove 7 on the outer surface of the rotor yoke 1, the guide groove 10 on both sides of the magnetic pole assembly 3 and the positioning guide strip 9 are in sliding fit to form the modular inclined pole unit 2; the locking screw 13 penetrates through the middle through hole of the magnetic pole assembly 3, the both ends are locked by the locking nut 14, the first baffle 11 and the second baffle 12 at both ends constrain the axial displacement of the magnetic pole assembly 3 through the inner working surface, the lower arc profile surface of the first baffle 11 is matched with the outer circle of the rotor yoke 1, the outer side plane of the first baffle 11 and the inner wall of the baffle ring 15 form the circumferential positioning; the spacer 16 of the locking screw 13 is arranged between the adjacent magnetic pole assemblies 3 to form the standardized gap 17, the double-layer heat dissipation air duct is formed by cooperating with the air-permeable groove 18 of the rotor yoke 1, the mounting hole 19 of the spacer 16 is matched with the locking screw 13, the positioning hole 20 on the spacer 16 is locked and prevented from rotating by the fixed nut 21 and the threaded hole 22 of the magnetic pole assembly 3, the upper arc surface 24 and the lower arc surface 25 of the water-drop-shaped tail end 23 of the spacer form a tapered tail wing to guide the airflow, and the height of the tail end 23 does not exceed the outer edge of the magnetic pole assembly 3 to construct the stepped aerodynamic protection; a plurality of magnetic pole groups 5 are arranged in an angular staggered manner along the axial direction of the rotor yoke 1 to form a continuous "V"-shaped groove 6, so as to realize the optimization of the magnetic field waveform and the smooth output of the torque.

[0047] The general magnetic steel 4 is selected from hard magnetic materials such as ferrite and neodymium iron boron; the magnetic pole mounting box one 5-5 and the magnetic pole mounting box two 5-6 are usually stacked from silicon steel sheets of the same shape punched or laser cut.

[0048] The different magnetic pole assemblies 3 have the same outer circular convex pole part, i.e. the magnetic pole mounting box, and the inner circular part, i.e. the magnetic pole base, the center of the outer circular arc surface of the outer circular convex pole part is on the center symmetry line of the inner circular part, the center alignment mechanism promotes the accurate matching of the magnetic center line of the stator and the rotor, effectively suppresses the phenomenon of axial magnetic pull caused by the displacement, guarantees the structural stability under high-speed rotation, and the main difference between the different magnetic pole assemblies 3 in shape is that the included angle between the center symmetry line of the outer circular convex pole part and the center symmetry line of the inner circular part is different.

[0049] In order to realize the inhibition of cogging torque, it is necessary to determine a certain skew angle value. The skew angle C is usually preferably a circumferential angle corresponding to one slot pitch, that is, 360 degrees divided by the total number of stator slots.

[0050] Assuming that there are N kinds of magnetic pole assemblies 3 (that is, there are N kinds of angles between the center symmetry lines of the outer circular salient pole portions and the center symmetry lines of the inner circular portions), the angle of the magnetic pole group one 5-1 is C / (4N), the angle of the magnetic pole group two 5-2 is 3C / (4N), the angle of the magnetic pole group three is 5C / (4N)…the angle of the magnetic pole group a is (2a-1)C / (4N), where a is the serial number, and the value range is 1, 2, 3…N.

[0051] When each skew pole unit 2 is arranged, the total number of blocks of the magnetic pole assembly 3 is usually more than the magnetic pole group 5, so it needs to be arranged in groups. By combining the magnetic pole groups 5 of different groups and the forward and reverse assembly [the outermost is the forward assembly magnetic pole assembly 3 (N groups), the inward is the forward assembly magnetic pole assembly 3 (N-1 groups), the forward assembly magnetic pole assembly 3 (N-2 groups)…the reverse assembly magnetic pole assembly 3 (N-1 groups), the reverse assembly magnetic pole assembly 3 (N-2 groups)…the reverse assembly magnetic pole assembly 3 (N groups)], the overall V-shaped skew pole unit 2 can be axially assembled.

[0052] Taking the number of magnetic pole groups 5 as two, the magnetic pole assembly 3 is composed of two magnetic pole group one 5-1 and magnetic pole group two 5-2, the total number of blocks of the magnetic pole assembly 3 is fourteen, and the outermost of the skew pole unit 2 is two forwardly installed magnetic pole group two 5-2, and the inward is the forwardly installed magnetic pole group one 5-1, the reversely installed magnetic pole group one 5-1, and the reversely installed magnetic pole group two 5-2 in the middle position.

[0053] When the rotor is assembled, first, the positioning strip 8 is placed in the positioning groove 7, and the positioning strip 8 is locked and fixed by bolts, then the corresponding number of magnetic pole group one 5-1 and magnetic pole group two 5-2 are selected according to the requirements, and are sequentially slid and installed into the positioning strip 8. Before this, the corresponding magnetic pole assembly 3 needs to be installed with a spacer 16. When assembling, it is necessary to have a spacer 16 between the two magnetic pole assemblies 3. When the magnetic pole assembly 3 is installed, the corresponding skew pole unit 2 is formed. The first baffle 11 and the second baffle 12 are arranged at both ends of the skew pole unit 2, the locking screw 13 passes through the entire skew pole unit 2, and the locking nut 14 provides a certain axial pre-tightening force to the skew pole unit 2. Finally, the skew pole unit 2 is fixed and installed by bolts at both ends of the positioning strip 8.

[0054] Finally should be explained a few points are: first, in the description of the present application, it should be pointed out that, unless otherwise specified and limited, the term "installation", "connected", "connection" should be broad, can be mechanical or electrical connection, but also can be two elements inside the communication, can be directly connected, "up", "down", "left", "right" and so on, only for indicating the relative position relationship, when the absolute position of the described object changes, the relative position relationship may change; Second: the present application discloses embodiment in the drawings, only involves the structure related to the present disclosure embodiment, other structure can refer to the usual design, in the case of no conflict, the same embodiment and different embodiments of the present application can be combined with each other; Finally: the above only is the preferred embodiment of the present application, and does not limit the present application, it should be pointed out that, for ordinary skilled in the art, without departing from the technical principles of the present application, can make a number of improvements and variations, these improvements and variations should also be considered the protection scope of the present application.

Claims

1. A permanent magnet motor rotor, comprising a rotor yoke (1), characterized in that: The outer surface of the rotor yoke (1) is evenly spaced with oblique pole units (2), the oblique 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), and a plurality of magnetic pole assemblies (3) form a magnetic pole group (5), and the plurality of magnetic pole groups (5) form a "V"-shaped groove (6) axially on the outer surface of the rotor yoke (1).

2. A permanent magnet motor rotor according to claim 1, characterized in that: The outer surface of the rotor yoke (1) is provided with a plurality of axially arranged positioning grooves (7), a positioning bar (8) is fixed in the positioning groove (7), both sides of the upper end of the positioning bar (8) extend outward to form a positioning guide bar (9), and both sides of the magnetic pole assembly (3) are provided with guide grooves (10) that cooperate with the positioning guide bar (9).

3. A permanent magnet motor rotor according to claim 2, characterized in that: A first baffle (11) and a second baffle (12) are fixed to the two ends of each two adjacent positioning bars (8), respectively. The inner side walls of the first baffle (11) and the second baffle (12) are in contact with the magnetic pole assemblies (3) at both ends of the oblique pole unit (2), providing outer end limit for the magnetic pole assemblies (3).

4. A permanent magnet motor rotor according to claim 3, characterized in that: A through hole is provided in the middle of each magnetic pole assembly (3), a locking screw (13) is provided in the through hole, both 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 baffle (11) and the second baffle (12), the arc-shaped lower edges of the first baffle (11) and the second baffle (12) are 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 raised retaining ring (15) on the outer edge of the rotor yoke (1).

5. A permanent magnet motor rotor according to any one of claims 1 to 4, characterized in that: A spacer (16) is provided between two adjacent magnetic pole assemblies (3) in the oblique pole unit (2) and is sleeved on the locking screw (13). The spacer (16) is used to separate the two magnetic pole assemblies (3) so that a gap (17) exists between the magnetic pole assemblies (3). A ventilation groove (18) corresponding to each gap (17) is provided on the circumference of the rotor yoke (1) below the gap (17). The gap (17) and the ventilation groove (18) are used for airflow to pass through.

6. A permanent magnet motor rotor according to claim 5, characterized in that: The spacer (16) has a mounting hole (19) in the middle thereof, which is sleeved on the locking screw (13). At least two positioning holes (20) are provided on one side of the mounting hole (19). A fixing nut (21) passes through the positioning hole (20) and is fixed in a threaded hole (22) of the magnetic pole assembly (3).

7. A permanent magnet motor rotor according to claim 6, characterized in that: The spacer (16) is in the shape of a teardrop, and the portion thereof away from the outer ring of the rotor yoke (1) is the 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). One end of the upper arc surface (24) and the lower arc surface (25) are gathered together and fitted together, so that the spacer tail end (23) is in a conical shape.

8. The permanent magnet motor rotor according to claim 7, characterized in that: The tail end (23) of the spacer does not extend beyond the outer edge surface of the magnetic pole assembly (3).

9. A method for arranging skewed pole units of a permanent magnet motor rotor, characterized in that: The oblique pole unit (2) is composed of N types of magnetic pole assemblies (3). The outermost of the magnetic pole assemblies (3) from the outside to the inside are the normal magnetic pole assembly (3) N, the normal magnetic pole assembly (3) N-1, the normal magnetic pole assembly (3) N-2... the reversed magnetic pole assembly (3) N-1, the reversed magnetic pole assembly (3) N-2... the reversed magnetic pole assembly (3) N, and finally the overall V-shaped oblique pole unit (2) is assembled axially.

10. The method for arranging skewed pole units of a permanent magnet motor rotor according to claim 9, characterized in that: When the magnetic pole group (5) is composed of a magnetic pole group 1 (5-1) and a magnetic pole group 2 (5-2), the magnetic pole group 1 (5-1) and the magnetic pole group 2 (5-2) both include a magnetic pole base 1 (5-3) and a magnetic pole base 2 (5-4) that are attached to the rotor yoke (1), and a magnetic pole mounting box 1 (5-5) and a magnetic pole mounting box 2 (5-6) are respectively located above the magnetic pole base 1 (5-3) and the magnetic pole base 2 (5-4); The center line of the first magnetic pole mounting box (5-5) forms an angle α with the center line of the first magnetic pole base (5-3), and the center line of the second magnetic pole mounting box (5-6) forms an angle β with the center line of the second magnetic pole base (5-4); The magnetic steel (4) is inserted into the magnetic pole mounting box 1 (5-5) and the magnetic pole mounting box 2 (5-6); The angle β is greater than the angle α.

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