A rotor structure for achieving skewed magnetic poles

Abstract

This utility model discloses a rotor structure for achieving skewed magnetic poles. It employs a segmented skewed rotor magnetic pole structure, comprising several segmented magnetic pole modules and a circular magnetic yoke with grooves. Each magnetic pole module has at least one magnet embedded in it and several through holes for axial and radial positioning and fixing. The inner circle of each magnetic pole module is fitted with the magnetic yoke by several protrusions distributed on both sides, with equal spacing between the protrusions on each side. Furthermore, the position of each magnetic pole module within the segmented skewed pole is determined by the distribution of its protrusions, and it is inserted into the grooves of the magnetic yoke in segments according to a preset skew angle to form a continuous skewed magnetic pole with a preset angle. This utility model can be used in conjunction with a straight stator slot design to improve stator winding efficiency and reduce stator manufacturing costs. The rotor does not increase costs compared to the original non-skewed pole design and is beneficial for engineering implementation. It can effectively weaken specific harmonics, thereby reducing cogging torque and torque pulsation. The axial force problem can be eliminated by designing different numbers of axial magnetic poles.

Description

Technical Field

[0001] This utility model relates to the field of motor manufacturing technology, specifically to a rotor structure that achieves skewed magnetic poles. 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.

[0003] In the current market, permanent magnet synchronous motors in the wind power field, especially semi-direct drive wind turbines, generally adopt a stator skewed slot and rotor non-skewed pole design to weaken specific harmonics, thereby effectively reducing cogging torque and improving motor operating characteristics. However, the stator skewed slot design brings inconvenience to manufacturing and winding, cannot improve work efficiency, and the skewed slot is only inclined in one direction, so the resulting unilateral axial force can easily affect the balance of the stator and rotor and have a certain impact on the bearings.

[0004] However, wind turbines have relatively large outer diameters, and the rotor magnetic poles are all magnetically mounted by uniformly dividing them into circumferential and axial segments. If the rotor were to use an integral skewed pole method, there would be torsion grooves, which would be impractical and inconvenient. Utility Model Content

[0005] This invention proposes a rotor structure implemented by skewed rotor magnetic poles, which can effectively reduce cogging torque, eliminate axial force, and facilitate engineering implementation.

[0006] The technical solution provided by this utility model is: a rotor structure for realizing skewed magnetic poles, characterized in that a segmented skewed rotor magnetic pole structure is adopted. The rotor includes several segmented magnetic pole modules and a circular magnetic yoke with grooves. Each magnetic pole module is embedded with at least one magnet and several through holes for axial and radial positioning and fixing. The inner circle of each magnetic pole module is fitted with the magnetic yoke by several protrusions distributed on both sides, and the distance between each protrusion on each side is the same. In addition, the position of each magnetic pole module in the segmented skewed pole is determined by the distribution of its protrusion positions, and it is inserted into the grooves of the magnetic yoke in segments according to the preset inclination of the skewed pole to form a whole magnetic pole skewed pole with a preset inclination.

[0007] In the rotor structure described above for achieving skewed magnetic poles, the magnetic poles are selected to be skewed by one tooth pitch, and as needed, they can be divided into two or three skewed segments, or even more skewed segments.

[0008] In the rotor structure described above for achieving skewed magnetic poles, the perforations are square holes, and at least two or more are provided.

[0009] In the rotor structure described above for achieving skewed magnetic poles, the length of each skewed pole segment is determined based on the rotor shaft length to form the magnetic poles.

[0010] In the rotor structure described above for achieving skewed magnetic poles, when the tooth pitch angle of the stator straight slots of the generator using this rotor structure is calculated to be a, and when the magnetic pole module is skewed in three segments, the spacing angle of each protrusion on both sides of the inner circle of the rotor magnetic pole module is a / 2; the spacing angle between the center line of the outermost protrusion and the edge line of the magnetic pole module is a / 4.

[0011] In the rotor structure described above for achieving skewed magnetic poles, the magnetic pole module is divided into a front section, a middle section, and a rear section, with the number of protrusions distributed on the left and right sides as 3+1, 2+2, and 1+3 respectively, while the rotation angle of the square steel in the corresponding square hole is a / 2.

[0012] In the rotor structure for achieving skewed magnetic poles described above, the number of grooves corresponding to the magnetic yoke is 3*2 per stage, that is, three grooves on each side. The distribution of the number of protrusions on the left and right sides is 3+1 and 1+3 respectively, which can realize the forward and reverse assembly of a single magnetic pole module, that is, it is only a composite installation of two magnetic pole modules.

[0013] In the rotor structure described above for achieving skewed magnetic poles, each magnetic pole module has one protrusion at each end.

[0014] In the rotor structure described above for achieving skewed magnetic poles, when the magnetic pole module is divided into four skewed sections, the number of protrusions on the left and right sides are 4+1, 3+2, 2+3, and 1+4, respectively. Among them, 4+1 and 1+4 can realize the forward and reverse assembly of a single magnetic pole module. Similarly, 3+2 and 2+3 are the same, that is, they are only two magnetic poles installed in a multi-directional composite manner.

[0015] This utility model adopts the above-mentioned rotor skewed pole structure, which can be combined with the stator straight slot design to improve stator winding efficiency and reduce stator manufacturing cost; the rotor does not increase cost compared with the original non-skewed pole design and is conducive to engineering implementation; it can effectively weaken specific harmonics, thereby reducing cogging torque and reducing torque pulsation;

[0016] The axial force problem can be eliminated by designing different numbers of axial magnetic pole modules. Attached Figure Description

[0017] Figures 1-2 These are schematic diagrams of the front and middle sections of the three-section skew-pole rotor lamination structure of this utility model;

[0018] Figures 3-4 , respectively corresponding Figure 1 and Figure 2 A schematic diagram of the magnetic pole module of this utility model;

[0019] Figure 5 This is a schematic diagram of the three-segment inclined magnetic yoke model of this utility model;

[0020] Figure 6 This is a schematic diagram of the assembled rotor structure of this utility model;

[0021] Figure 7 This is a schematic diagram of the lamination structure of this utility model, where each magnetic pole module has one protrusion at each end. Detailed Implementation

[0022] This utility model discloses a rotor structure for achieving skewed magnetic poles, which adopts a segmented skewed rotor magnetic pole structure design, as detailed below.

[0023] See Figure 5-6 The rotor structure consists of segmented rotor magnetic pole modules 3 and a circular magnetic yoke.

[0024] Each magnetic pole module consists of one or more magnets and square holes for mounting axial and radial positioning and fixing square steel. There can be two symmetrical square holes, or three or more.

[0025] Each magnetic pole module 3 has several protrusions 1, similar in shape to sections of the Great Wall, on its inner circle. These protrusions are inserted into the grooves 2 of the yoke.

[0026] The position of protrusion 1 determines the angle of the slant pole of magnetic pole module 3;

[0027] The magnetic pole module 3 is generally slanted by one tooth pitch, but can be divided into two, three, or more slanted sections as needed. This tooth pitch refers to the distance between the center lines of adjacent straight slots on the stator of the generator that mates with the rotor structure of this invention.

[0028] The following is a detailed explanation using the three-segment inclined embodiment.

[0029] See Figure 1 and Figure 2 There are two types of rotor lamination structures with three skewed poles.

[0030] Figure 1 It is a front rotor lamination structure. Figure 2 It is a mid-section rotor lamination structure, and Figure 2 The reverse-mounted version is the rear rotor lamination structure.

[0031] After designing the length of each section according to the rotor shaft length, it becomes... Figure 3 and Figure 4 Magnetic pole module;

[0032] Figure 5 The required magnetic yoke model for the three-segment inclined configuration. Figure 6This is the assembled rotor structure.

[0033] When the stator straight slot of the generator using this rotor structure is calculated to have a tooth pitch angle of α, see [reference needed]. Figure 1 When the rotor is divided into three inclined sections, the spacing angle between each protrusion on the inner circle of the rotor magnetic pole module is a / 2; the spacing angle between the center line of the outermost protrusion and the edge line of the magnetic pole module is a / 4.

[0034] If the magnetic pole module is divided into front, middle, and rear sections, the number of protrusions from left to right is 3+1, 2+2, and 1+3 respectively. Simultaneously, the corresponding square steel rotation angle is a / 2, and the number of corresponding magnetic yoke grooves is 3*2 per stage, that is, 3 grooves on each side.

[0035] The position of each magnetic pole module within the segmented skewed pole is determined by the protrusions. In reality, the magnetic pole modules are not skewed; they are segmented at different angles to form a complete magnetic pole, simulating the entire skew. The number of segments determines the equivalent skew angle; the more segments, the higher the equivalence. However, in practical applications, three segments are the minimum.

[0036] See Figure 7 In another embodiment, the yoke remains stationary, and the number of protrusions in each magnetic pole module can be simplified to one at each end, see [reference]. Figure 7 That is, the magnetic pole module protrusions only retain the leftmost and rightmost two.

[0037] More implementation options include, according to the rules, the magnetic pole module can be divided into four or more inclined sections. If divided into four sections, the number of protrusions on the left and right sides are 4+1, 3+2, 2+3, and 1+4 respectively. Among them, 4+1 and 1+4 can realize the forward and reverse assembly of a single magnetic pole module. Similarly, 3+2 and 2+3 are the same, that is, it is only a multi-directional composite installation of two magnetic pole modules.

[0038] Those skilled in the art should recognize that the above embodiments are only used to illustrate the present utility model and are not intended to limit the present utility model. Any changes or modifications to the above embodiments within the scope of the essential spirit of the present utility model will fall within the scope of the claims of the present utility model.

Claims

1. A rotor structure for achieving skewed magnetic poles, characterized in that, A segmented skewed-pole rotor magnetic pole structure is adopted, wherein the rotor includes several segmented magnetic pole modules and a fully circular magnetic yoke with grooves. Each magnetic pole module is embedded with at least one magnet and several through holes for axial and radial positioning and fixing. The inner circle of each magnetic pole module is fitted with the magnetic yoke by several protrusions distributed on both sides, with the protrusions on each side having the same spacing. In addition, the position of each magnetic pole module in the segmented inclined pole is determined by the distribution of its protrusions, and it is inserted into the groove of the magnetic yoke in segments according to the preset inclination of the inclined pole to form a whole magnetic pole inclined pole with a preset inclination.

2. The rotor structure for achieving skewed magnetic poles according to claim 1, characterized in that, The magnetic pole is selected to be inclined by one tooth pitch, and can be divided into two or three inclined segments, or even more inclined segments, as needed.

3. A rotor structure for achieving skewed magnetic poles according to claim 1 or 2, characterized in that, The perforations are square holes, and at least two or more are provided.

4. A rotor structure for achieving skewed magnetic poles according to claim 3, characterized in that, After determining the length of each segment of the skew pole based on the rotor shaft length, magnetic poles are formed.

5. A rotor structure for achieving skewed magnetic poles according to claim 4, characterized in that, When the stator straight slot of the generator using this rotor structure is calculated to have a tooth pitch angle of a, and the magnetic pole module is divided into three inclined segments, the pitch angle of each protrusion on both sides of the inner circle of the rotor magnetic pole module is a / 2; the pitch angle between the center line of the outermost protrusion and the edge line of the magnetic pole module is a / 4.

6. A rotor structure for achieving skewed magnetic poles according to claim 5, characterized in that, The magnetic pole module is divided into a front section, a middle section, and a rear section. The number of protrusions on the left and right sides are distributed as 3+1, 2+2, and 1+3 respectively, and the rotation angle of the square steel in the corresponding square hole is a / 2.

7. A rotor structure for achieving skewed magnetic poles according to claim 6, characterized in that, The number of grooves corresponding to the magnetic yoke is 3*2 per level, that is, three grooves on each side. The number of protrusions is distributed on the left and right sides as 3+1 and 1+3 respectively, which can realize the forward and reverse assembly of a single magnetic pole module, that is, it is only a composite installation of two magnetic pole modules.

8. A rotor structure for achieving skewed magnetic poles according to claim 1, characterized in that, Each magnetic pole module has one protrusion at each end.

9. A rotor structure for achieving skewed magnetic poles according to claim 1, characterized in that, When the magnetic pole module is divided into four oblique pieces, the number of protrusions on the left and right sides are 4+1, 3+2, 2+3, and 1+4, respectively. Among them, 4+1 and 1+4 can realize the forward and reverse assembly of a single magnetic pole module. Similarly, 3+2 and 2+3 are the same, that is, it is only a multi-directional composite installation of two magnetic poles.

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