Rotor structure and motor with same

Abstract

The invention provides a rotor structure and a motor with the rotor structure, the rotor structure comprises rotor core units which are divided into a plurality of sections in the axial direction, each rotor core unit is provided with a plurality of magnetic steel grooves, magnets are arranged in the magnetic steel grooves, and the adjacent rotor core units are connected in a staggered manner in the circumferential direction; a plurality of positioning hole groups are formed in the rotor core unit, the rotor structure rotates anticlockwise, and a first positioning hole group is correspondingly formed in the first side of the center line of the magnetic steel groove; or the rotor structure rotates clockwise, and the second side of the center line of the magnetic steel groove is correspondingly provided with a positioning hole group. The arrangement position of the positioning hole group is related to the rotation direction of the rotor, the arrangement of the positioning hole group makes the magnetic lines of force of the motor distort according to the rotation direction of the motor, the purpose is to influence the distribution of the magnetic lines of force as much as possible, and the torque pulsation of the motor can be reduced through the arrangement.

Description

Technical Field

[0001] The present invention belongs to the technical field of motors, and in particular relates to a rotor structure and a motor having the rotor structure. Background Art

[0002] In the field of electromagnetic design, methods to reduce motor vibration and noise include reasonable pole slot matching and winding selection, optimizing pole arc coefficient, opening auxiliary slots in the stator, increasing air gap width, etc. For built-in motors, methods of optimizing magnetic barrier angle and changing the direction of magnetic lines of force can also be used. Stator skew slots or rotor skew poles can reduce tooth harmonics caused by the slot effect and greatly reduce the motor's slot torque and ripple torque, thereby reducing the vibration and noise of the motor. When the electromagnetic scheme is fixed and the stator and rotor have been molded, skew slots / skew poles are the most economical and effective way to reduce slot torque and torque pulsation. However, the stator skew slot process is complicated in mass production, the lamination skew slot is difficult, and it is not easy to automatically embed wires after the skew slot. Compared with the stator skew slot, the rotor segmented skew pole is obviously a better choice.

[0003] A segmented rotor skewed pole structure for a permanent magnet synchronous motor is publicly proposed in the related art. In order to reduce the torque pulsation of a specific order, the staggered angle of the segmented rotor is not exactly the same as the axial length. This technology does not take into account the staggering of the rotor core at different angles without reopening the mold. If this design is to be realized, a rotor punching sheet is specially designed for each segment of the rotor core to stagger at different angles, which greatly increases the mold cost. A vehicle permanent magnet synchronous motor rotor structure with arbitrary segmented skewed slots is publicly proposed in the related art. It has a plurality of key slots arranged along the circumferential direction on the outer diameter of the rotor punching sheet, and a flat key slot is opened along the axial direction on the rotating shaft. During assembly, the key slots are ensured to overlap to achieve segmented rotor skewed poles. This design will increase the relative width of the air gap, thereby reducing the rated torque of the motor and changing the motor performance. Summary of the invention

[0004] The present invention provides a rotor structure and a motor having the rotor structure, which can solve the technical problem that for a molded motor, the design scheme of the motor is fixed, and the optimization method for torque pulsation and harmonic loss will affect the performance of the motor.

[0005] The present invention provides a rotor structure, comprising a rotor core unit divided into multiple sections in the axial direction, each of the rotor core units is provided with multiple magnetic steel slots, and magnets are arranged in the magnetic steel slots, characterized in that: adjacent rotor core units are staggered and connected in the circumferential direction;

[0006] The rotor core unit is provided with a plurality of positioning hole groups. When the rotor structure rotates counterclockwise, along the radial direction of the rotor core unit, the first positioning hole group is correspondingly provided on the first side of the center line of the magnetic steel slot;

[0007] Or the rotor structure rotates clockwise, and along the radial direction of the rotor core unit, the second side of the center line of the magnetic steel slot is correspondingly provided with the positioning hole group.

[0008] In some embodiments, the positioning hole group includes a plurality of positioning through holes, the plurality of positioning through holes are arranged along the circumference of the rotor core unit, and adjacent rotor core units are connected with one positioning through hole staggered therebetween.

[0009] In some embodiments, the number of the positioning through holes is m, the number of segments of the rotor structure is n, and the number m and the number n satisfy: m=n.

[0010] In some embodiments, a line connecting the center of the positioning through hole and the center of the rotor core unit is a first straight line, a line connecting the center of adjacent positioning through holes and the center of the rotor core unit is a second straight line, an angle θ is provided between the first straight line and the second straight line, the angle θ is 1°, and the staggered angle between adjacent rotor core units is 1°.

[0011] In some embodiments, the positioning hole group includes eight positioning through holes, the eight positioning through holes are arranged at intervals, and the distance from the center of each positioning through hole to the center of the rotor core unit is the same, the rotor structure is segmented into eight rotor core units, and the staggered angle between the first rotor core unit and the eighth rotor core unit is 7°.

[0012] In some embodiments, there is a magnetic isolation bridge between the positioning through hole close to the magnetic steel slot and the magnetic steel slot, and the vertical distance between the outer circle of the positioning through hole and the circumferential outer side of the magnetic steel slot is the width of the magnetic isolation bridge, and the width is L, and the width L satisfies: 0.5mm≤L≤1mm.

[0013] In some embodiments, adjacent positioning through holes are arranged tangentially, or adjacent positioning through holes are arranged to intersect, or adjacent positioning through holes are arranged to be spaced apart.

[0014] In some embodiments, in the radial direction of the rotor core unit, the magnetic steel slot is in a straight line shape, and the positioning hole group is located on the radial outside of the magnetic steel slot; or the magnetic steel slot is in a V-shape, and the positioning hole group is located in the opening of the magnetic steel slot; or the magnetic steel slot is in a U-shape, and the positioning hole group is located in the opening of the magnetic steel slot.

[0015] In some embodiments, the magnetic steel slot is a multi-layer slot structure, and in the radial direction of the rotor core, the positioning hole group is close to the outermost magnetic steel slot.

[0016] A motor comprises a rotor structure, wherein the rotor structure is the above-mentioned rotor structure.

[0017] A rotor structure and a motor having the rotor structure provided by the present invention have the following beneficial effects:

[0018] The setting position of the positioning hole group of the present invention is related to the rotation direction of the rotor. According to the direction of rotation of the motor, the setting of the positioning hole group causes the magnetic lines of force of the motor to be distorted, with the purpose of affecting the distribution of the magnetic lines of force as much as possible. This setting can reduce the torque pulsation of the motor, and each rotor core unit in the present embodiment is of this kind. On the one hand, the rotor can be tilted by a set of molds without the need to replace the molds; on the other hand, by changing the setting position of the positioning hole group, the back electromotive force harmonics and torque pulsation of the motor can be reduced without causing the performance of the motor to decline. Compared with the general tilted pole motor, this setting method produces smaller torque pulsation and tooth slot torque after the rotor structure of the present embodiment is applied. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the implementation methods of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for the implementation methods or the description of the prior art. Obviously, the drawings in the following description are only exemplary, and for ordinary technicians in this field, other implementation drawings can be derived from the provided drawings without creative work.

[0020] Figure 1 is a schematic diagram of a rotor structure according to an embodiment of the present invention;

[0021] Figure 2 is a schematic diagram of the angle θ of an embodiment of the present invention;

[0022] Figure 3 Schematic diagram of the width L of the magnetic isolation bridge according to an embodiment of the present invention;

[0023] Figure 4 It is an enlarged view of the details of the rotor structure of an embodiment of the present invention;

[0024] Figure 5 A schematic diagram of a straight-line magnetic steel slot according to an embodiment of the present invention;

[0025] Figure 6 Schematic diagram of a U-shaped magnetic steel slot according to an embodiment of the present invention;

[0026] Figure 7 A schematic diagram of a multi-layer magnetic steel slot according to an embodiment of the present invention;

[0027] Figure 8 The torque and torque pulsation simulation diagram of the motor without positioning through holes in scheme 1;

[0028] Fig. 9 The torque and torque pulsation simulation diagram of the motor with a positioning through hole set on the center line of the magnetic steel slot in scheme 2;

[0029] Fig.10 The torque and torque ripple simulation diagram of the motor with symmetrical center positioning through-hole offset in scheme 3;

[0030] Fig.11 The torque and torque ripple simulation diagram of the motor with the positioning hole group set in this embodiment;

[0031] Fig.12 This is the magnetic field line distribution cloud diagram of the motor in scheme 1;

[0032] Fig.13 This is the magnetic field line distribution cloud diagram of the motor in scheme 2;

[0033] Fig.14 This is the magnetic field line distribution cloud diagram of the motor in scheme 3;

[0034] Fig.15 This is the magnetic field line distribution cloud diagram of the motor in scheme 4;

[0035] Fig.16 Schematic diagram of a motor according to an embodiment of the present invention.

[0036] Figures: 1- rotor core unit; 2- magnetic steel slot; 21- first side of the center line of the magnetic steel slot; 22- second side of the center line of the magnetic steel slot; 3- positioning hole group; 301- positioning through hole; 4- magnetic isolation bridge; 5- stator; 6- magnet. DETAILED DESCRIPTION

[0037] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is by no means intended to limit the present invention and its application or use. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0038] In the description of the present invention, it is necessary to understand that the directions or positional relationships indicated by directional words such as "front, back, up, down, left, right", "lateral, vertical, perpendicular, horizontal" and "top, bottom" are usually based on the directions or positional relationships shown in the drawings. They are only for the convenience of describing the present invention and simplifying the description. Unless otherwise specified, these directional words do not indicate or imply that the devices or elements referred to must have a specific direction or be constructed and operated in a specific direction. Therefore, they cannot be understood as limiting the scope of protection of the present invention. The directional words "inside and outside" refer to the inside and outside relative to the contours of each component itself.

[0039] For ease of description, spatially relative terms such as "above", "above", "on the upper surface of", "above", etc. may be used here to describe the spatial positional relationship between a device or feature and other devices or features as shown in the figure. It should be understood that spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation described in the figure. For example, if the device in the accompanying drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below other devices or structures". Thus, the exemplary term "above" can include both "above" and "below". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatially relative descriptions used here are interpreted accordingly.

[0040] In addition, it should be noted that the use of terms such as "first" and "second" to limit components is only for the convenience of distinguishing the corresponding components. If not otherwise stated, the above terms have no special meaning and therefore cannot be understood as limiting the scope of protection of the present invention.

[0041] See also Figures 1 to 4 As shown, according to an embodiment of the present invention, a rotor structure is provided, including a rotor core unit 1 divided into multiple sections in the axial direction, each rotor core unit 1 is provided with a plurality of magnetic steel slots 2, magnets are arranged in the magnetic steel slots 2, and adjacent rotor core units 1 are staggered and connected in the circumferential direction; a plurality of positioning hole groups 3 are provided on the rotor core unit 1, and when the rotor structure rotates counterclockwise, a first side 21 of the center line of the magnetic steel slot 2 is correspondingly provided with a first positioning hole group 3 along the radial direction of the rotor core unit 1; or when the rotor structure rotates clockwise, a second side 22 of the center line of the magnetic steel slot 2 is correspondingly provided with a positioning hole group 3 along the radial direction of the rotor core unit 1.

[0042] It is worth noting that, in the circumferential direction of the rotor core unit 1, the first side 21 of the center line of the magnetic steel slot 2 refers to the left side, that is, the left side of the positioning hole group 3 close to the magnetic steel slot 2; the second side 22 of the center line of the magnetic steel slot 2 refers to the right side, that is, the right side of the positioning hole group 3 close to the magnetic steel slot 2.

[0043] Specifically, compared with the no-load operation of the motor, when the motor is loaded, the armature reaction of the stator 5 distorts the air gap magnetic field, thereby dragging the rotor to rotate. Therefore, the magnetic lines of force on the rotor are equivalent to being distributed along the rotation direction of the motor. When the motor runs counterclockwise (generally this operating mode), from the perspective of the magnetic lines of force, there is a certain phase difference between the stator 5 and the rotor magnetic lines of force. In order to guide the direction of the magnetic lines of force, a positioning hole group 3 is set on the left side of each magnetic steel slot 2 to change the direction of the magnetic lines of force; when the motor runs clockwise, a positioning hole group 3 is set on the right side of each magnetic steel slot 2, which also changes the direction of the magnetic lines of force in this state. Each rotor core unit 1 is set in this way, and the rotor core units 1 are staggered and stacked. In this embodiment, adjacent rotor core units 1 are connected by screws, and the screws are connected by penetrating the positioning hole group 3 to achieve staggered connection between the rotor core units 1.

[0044] In this embodiment, the setting position of the positioning hole group 3 is related to the rotation direction of the rotor. According to the direction of rotation of the motor, the setting of the positioning hole group 3 causes the magnetic lines of force of the motor to be distorted, with the purpose of affecting the distribution of the magnetic lines of force as much as possible. This setting can reduce the torque pulsation of the motor, and each rotor core unit 1 in this embodiment is set in this way. On the one hand, the rotor can be tilted by a set of molds without the need to replace the mold; on the other hand, by changing the setting position of the positioning hole group 3, the back electromotive force harmonics and torque pulsation of the motor can be reduced without causing the performance of the motor to decline. Compared with the general tilted pole motor, this setting method generates smaller torque pulsation and tooth slot torque after the rotor structure of this embodiment is applied.

[0045] As a specific implementation, the positioning hole group 3 is close to the radial outer circle of the rotor core unit 1, and the positioning hole group 3 should be set at a position that causes large distortion of the rotor magnetic lines of force. While optimizing the motor air gap magnetic density waveform, it is also easier to achieve multi-segment skew poles of the rotor.

[0046] As a specific implementation, each rotor core unit 1 is formed by laminating rotor punching sheets, and then adjacent rotor core units 1 are rotated and staggered by a certain angle, and then a screw is inserted into the positioning hole group 3 to connect the rotor core units 1.

[0047] See also Figures 1 to 4As shown, the positioning hole group 3 includes a plurality of positioning through holes 301 , and the plurality of positioning through holes 301 are arranged along the circumferential direction of the rotor core unit 1 , and adjacent rotor core units 1 are connected with one positioning through hole 301 staggered therebetween.

[0048] Specifically, staggering one positioning through hole 301 means that, when the rotor core units 1 are connected, the first positioning through hole 301 of the second rotor core unit 1 is aligned with the second positioning through hole 301 of the first rotor core unit 1, and the two positioning hole groups 3 are connected in the axial direction by setting a screw, and the positioning hole groups 3 corresponding to each magnetic steel slot 2 are connected in this way, and the first rotor core unit 1 and the second rotor core unit 1 are connected in this way; when the third rotor core unit 1 needs to be installed, the third positioning through hole 301 of the third rotor core unit 1 is aligned with the second positioning through hole 301 of the second rotor core unit 1, at this time, the third rotor core unit 1 is staggered by one positioning through hole 301 with the second rotor core unit 1, and is staggered by two positioning through holes 301 with the first rotor core unit 1. If more than three rotor core units 1 are set, the above-mentioned staggered connection method is also adopted.

[0049] In this embodiment, not only the setting position of the positioning hole group 3 is optimized, but also the setting number of the positioning through holes 301 of the positioning hole group 3 is optimized. Compared with the conventional setting of one positioning through hole 301 on each rotor core unit 1, the setting angle of the positioning through holes 301 on the adjacent rotor core units 1 is deflected to achieve the oblique pole connection. This embodiment optimizes the setting number of positioning through holes 301, so that the setting position and number of the positioning hole group 3 on each rotor core unit 1 are the same, and the oblique pole connection can still be achieved. This staggered connection method can effectively disperse stress. The design of the positioning through holes 301 enables the rotor core units 1 to be accurately aligned during the assembly process, avoiding the connection offset between the rotor core units 1 due to improper alignment, and reducing the performance problems caused by assembly errors. Moreover, compared with the traditional skew slot or oblique pole design, the staggered connection method of the positioning hole group 3 can simplify the manufacturing process and reduce production costs. Since there is no need to reopen the mold, only adjustments need to be made based on the existing design to achieve better motor performance. In summary, optimizing the setting position of the positioning hole group 3 and the number of positioning through holes 301 can improve the magnetic field distribution of the motor, thereby improving the efficiency and performance of the motor. An effective connection method helps to reduce energy loss and improve the overall working efficiency of the motor.

[0050] It is worth noting that the specific tilted pole method in this embodiment is a prior art and will not be described in detail here.

[0051] See also Figures 1 to 4As shown, the number of positioning through holes 301 is m, the number of segments of the rotor structure is n, and the number m and the number n satisfy: m=n.

[0052] In this embodiment, since the rotor core is segmented as a whole, and each rotor core unit 1 is connected through the positioning through hole 301, the number of the positioning through holes 301 and the number of segments of the rotor structure are set correspondingly, so that each rotor core unit 1 can be accurately staggered and connected during connection to form a uniformly distributed staggered structure, thereby effectively reducing torque pulsation and vibration. In addition, it can avoid opening useless positioning through holes 301, simplify the assembly process, improve assembly efficiency and accuracy, and make the connection between each rotor core unit 1 more standardized, reducing performance differences caused by improper assembly.

[0053] See also Figures 1 to 4 As shown, the line connecting the center of the positioning through hole 301 and the center of the rotor core unit 1 is a first straight line, and the line connecting the center of the adjacent positioning through hole 301 and the center of the rotor core unit 1 is a second straight line. There is an angle θ between the first straight line and the second straight line, and the angle θ is 1°. The staggered angle between adjacent rotor core units 1 is 1°.

[0054] In this embodiment, the torque pulsation during the operation of the motor can be effectively reduced by a staggered angle of 1°. Torque pulsation is a nonlinear phenomenon caused by uneven magnetic field distribution during the operation of the motor. This small angle misalignment can make the magnetic field distribution more uniform, thereby reducing torque pulsation. Compared with other complex misalignment or skew slot designs, a staggered angle of 1° is easier to achieve in the manufacturing process, which can simplify the production process and reduce costs. Moreover, this design does not require changing the basic shape and size of the rotor core unit 1, so the compactness of the motor structure can be maintained. It is worth noting that in this embodiment, the staggered angle is 1°, which is set in combination with the number of segments of the rotor structure and the angle specified by the skew angle.

[0055] See also Figures 1 to 4 As shown, the positioning hole group 3 includes eight positioning through holes 301, the eight positioning through holes 301 are arranged at intervals, and the distance from the center of each positioning through hole 301 to the center of the rotor core unit 1 is the same, the rotor structure is segmented into eight rotor core units 1, and the staggered angle between the first rotor core unit 1 and the eighth rotor core unit 1 is 7°.

[0056] In this embodiment, for a structure with a large number of rotor core segments, if the diameter of each positioning through hole 301 is opened very large, it will also affect the overall rigidity of the rotor core. In this embodiment, the number of segments is large, but the corresponding opening diameter of each positioning through hole 301 is also small, so that the connection of multiple segments of the rotor core unit 1 can be achieved. In addition, the distance from the center of each positioning through hole 301 to the center of the rotor core unit 1 is the same. This uniform distribution helps to improve assembly accuracy, ensure accurate alignment between the rotor core units 1, and reduce performance problems caused by assembly errors. This embodiment can ensure that the connection between the rotor core units 1 is more stable through precise staggered connection and uniformly distributed positioning through holes 301, thereby improving the reliability and durability of the motor.

[0057] See also Figures 1 to 4 As shown, there is a magnetic isolation bridge 4 between the positioning through hole 301 close to the magnetic steel slot 2 and the magnetic steel slot 2, and the vertical distance between the outer circle of the positioning through hole 301 and the circumferential outer side of the magnetic steel slot 2 is the width of the magnetic isolation bridge 4, and the width is L, and the width L satisfies: 0.5mm≤L≤1mm.

[0058] Specifically, since the positioning hole group 3 is offset relative to the center line of the magnetic steel slot 2, the positioning hole group 3 is close to the magnetic steel slot 2. However, if the positioning hole group 3 is too close to the magnetic steel slot 2, it will also affect the stiffness of the rotor core unit 1. For this reason, in this embodiment, 0.5mm≤L≤1mm can not only optimize the direction of the magnetic lines of force, but also ensure the stiffness of the rotor core unit 1.

[0059] In this embodiment, since the setting position of the positioning hole group 3 is changed, the role of the magnetic isolation bridge 4 is to artificially create a smaller magnetic line of force path, so that the magnetic lines of force here are more concentrated and the magnetic density is greater. Due to the nonlinear characteristics of the magnetic circuit, the magnetic resistance here will also become very large, thereby changing the path of the magnetic lines of force, and achieving the effect of reducing torque pulsation. In theory, the magnetic bridge should be as small as possible, but the design of the magnetic isolation bridge 4 needs to find a balance between reducing magnetic leakage and ensuring the mechanical strength of the rotor. Under high-speed rotation, the centrifugal force on the rotor is large, so it is necessary to have sufficient mechanical strength to resist this force, avoid material buckling or fracture, and avoid the possibility of magnetic bridge fracture in actual operation. Therefore, the given range is 0.5mm≤L≤1mm. It is worth noting that the width of the magnetic bridge is defined by the distance between the positioning through hole 301 closest to the magnetic steel slot 2 and the magnetic steel slot 2, and has nothing to do with the structure of the positioning hole group 3.

[0060] As a specific implementation method, the positioning through hole 301 that is closest to the magnetic steel slot 2 and affects the magnetic lines of force the most has the greatest impact on the performance of the motor. Therefore, it is meaningful to limit the positioning through hole 301 closest to the magnetic steel slot 2. The purpose of the positioning through hole 301 is to allow the screw to pass through the positioning hole to achieve the oblique pole of the rotor. Its minimum diameter should not be less than the minimum diameter of the screw. The minimum diameter of the screw is 4mm. The corresponding minimum diameter of the positioning through hole 301 must be greater than 4mm to ensure that the screw can be installed in the positioning through hole 301. The maximum diameter of the positioning through hole 301 can be unrestricted, and the screw can be fixed by glue injection, while the diameters of the remaining positioning through holes 301 can be unrestricted.

[0061] See also Figures 1 to 4 As shown, adjacent positioning through holes 301 are arranged tangentially, or adjacent positioning through holes 301 are arranged intersectingly, or adjacent positioning through holes 301 are arranged at intervals.

[0062] Specifically, the distances from the center of the plurality of positioning through holes 301 to the center of the rotor core unit 1 are the same, which is R. The radius of the positioning holes is the same, which is r. The spacing angle between the positioning through holes 301 is the angle θ. For motors with different pole slot combinations, the relationship between the angle θ between the positioning through holes and the pole slot combination is θ=360° / LCM(Z,2p) / n, where Z is the number of stator slots and 2p is the number of rotor pole pairs. The positioning through holes 301 may intersect, cut first, or separate, and their states are related to these three forms, the spacing angle θ between the positioning through holes 301, and the spacing R and radius r. If Then the positioning through holes 301 intersect each other. The positioning through holes 301 are tangent to each other. The positioning through holes 301 are spaced apart from each other.

[0063] Specifically, the optimal skew angle of the motor is 360° / LCM(Z,2p), where Z is the number of stator slots, 2p is the number of rotor pole pairs, and the lowest common multiple of the number of motor pole slots is 48, so the optimal skew angle of the motor is 7.5°. In order to achieve multi-stage skew of the rotor, this embodiment provides a plurality of continuous through holes to place the screws. Based on position considerations, the positioning through holes 301 are connected to the positioning through holes 301, and each group of positioning hole groups 3 consists of 8 adjacent positioning through holes 301, each adjacent positioning hole is 1° apart, and the length of the center of each positioning through hole 301 from the center of the rotor is consistent.

[0064] In this embodiment, the positioning through hole 301 closest to the magnetic steel slot 2 affects the number of magnetic lines of force the most, and the positioning through hole 301 at a long distance has a smaller effect on the magnetic lines of force, so the three states of tangency, comparison and spacing have little effect on the electromagnetic performance of the motor itself. However, when the rotor core stack height is certain, and the more segments the rotor core has, the more positioning holes are required. When there are too many positioning through holes 301, the holes will intersect with each other, and when the number of segments is small, the holes will be separated from each other. By adjusting the relative position (tangent, intersection or separation) between the positioning through holes 301, the distribution and direction of the magnetic lines of force can be affected, thereby optimizing the electromagnetic performance of the motor. Different setting states (tangent, intersection or separation) have different degrees of influence on the magnetic lines of force, which can be adjusted according to the specific motor design requirements.

[0065] As a specific implementation, the distance R between each positioning through hole 301 and the rotor core unit 1 may also be different, but it is necessary to ensure that the positioning through hole 301 with the largest distance R to the rotor core unit 1 is spaced greater than 1 mm from the outer circle of the rotor core unit 1 .

[0066] As a specific implementation, the illustration of this embodiment only shows that the positioning through hole 301 is circular. In other embodiments, its shape may also be triangular, quadrilateral, or even polygonal.

[0067] See also Figure 1 , Figures 5 to 7 As shown, in the radial direction of the rotor core unit 1, the magnetic steel slot 2 is in a straight line shape, and the positioning hole group 3 is located on the radial outside of the magnetic steel slot 2; or the magnetic steel slot 2 is in a V-shape, and the positioning hole group 3 is located in the opening of the magnetic steel slot 2; or the magnetic steel slot 2 is in a U-shape, and the positioning hole group 3 is located in the opening of the magnetic steel slot 2.

[0068] Specifically, for magnetic steel slots 2 of different shapes, the width of the magnetic isolation bridge 4 must satisfy 0.5mm≤L≤1mm. However, in order to ensure the rigidity of the rotor core unit 1, the distance between the magnetic steel slots 2 of each shape and the outer circle of the rotor core unit 1 is different. For the straight-line magnetic steel slots 2, the positioning through hole 301 is located on the left side of the straight-line magnetic steel slots 2 of each pole, and the width of the magnetic isolation bridge 4 between the positioning through hole 301 and the magnetic steel slot 2 should satisfy 0.5mm~1mm, and the spacing between the positioning through hole 301 and the outer circle of the rotor is greater than 1mm. For V-shaped rotors, the positioning through hole 301 is located on the left side of the magnetic steel slot 2 of each pole of the motor and close to the air gap, and the spacing between the positioning through hole 301 and the outer circle of the rotor is greater than 1mm; for U-shaped rotors, the spacing between the positioning through hole 301 and the U-shaped left rib magnetic steel slot 2 is 0.5~1mm, and the spacing between the positioning through hole 301 and the outer circle of the rotor is greater than 1mm.

[0069] See also Figure 7As shown, the magnetic steel slot 2 is a multi-layer slot structure, and in the radial direction of the rotor core, the positioning hole group 3 is close to the outermost magnetic steel slot 2.

[0070] As a specific implementation method, the rotor of this embodiment has 8 poles, and the magnetic steel is inserted into the magnetic barrier along the circumference according to the NSNS rule. The rotor core is usually locked by a screw, so a positioning through hole 301 is added to the rotor core to place the screw. Each pole is provided with a magnetic steel slot 2 and a positioning hole group 3, that is, the magnetic steel slot 2 can be provided with multiple layers, but combined with the skew pole requirement of the rotor core unit 1, only one positioning hole group 3 is provided for each pole. In other embodiments, multiple positioning hole groups 3 can be provided for each pole according to the motor performance requirements.

[0071] See also Fig.16 As shown, a motor includes a rotor structure, and the rotor structure is the rotor structure mentioned above.

[0072] As an electromagnetic conversion device, the energy of the motor is mainly stored in the air gap. When the rotor rotates and causes the change of the air gap energy, part of the magnetic field energy in the air gap will be converted into mechanical energy to realize the electromechanical energy conversion. The air gap magnetic field energy is provided by the stator 5 and the rotor. The magnetomotive force generated by the stator 5 winding can be calculated by the winding function method. For the rotor magnetomotive force, if the rotor is used as the reference system, the magnetomotive force generated by the rotor is (assuming that the rotor has a pair of poles):

[0073]

[0074] If the stator 5 is taken as the reference system, then:

[0075]

[0076] Among them, F r is the rotor magnetomotive force, υ is the harmonic order, F υ is the rotor harmonic magnetomotive force, α is the rotor position angle, and θ is the current angle. The permanent magnet rotor will generate a harmonic magnetomotive force. For a three-phase permanent magnet synchronous motor, the harmonic magnetomotive force will have an adverse effect on the motor operation.

[0077] According to the conventional positioning through hole 301, this embodiment specifically involves three rotor structures for comparison. Taking the motor with a V-shaped rotor pole as an example, the first solution is that the positioning through hole 301 is not set on the rotor core. The torque pulsation and magnetic path direction are as follows Figure 8 and 12 As shown; the second solution is to set a positioning through hole 301 on the center line of the magnetic steel slot 2, and a positioning through hole 301 is also set on both sides of the positioning through hole 301. The torque pulsation and magnetic circuit direction are as follows Fig. 9 and Fig.13As shown; the third solution is that the positioning hole deviates from the symmetry center by 1°, and the torque pulsation and magnetic circuit direction are as follows Fig.10 and Fig.14 As shown; the torque pulsation and magnetic circuit direction of this embodiment are as follows Fig.11 and Fig.15 When the positioning through hole 301 is set at different positions, the average torque and torque pulsation of the motor are shown in the following figure:

[0078]

[0079] It can be seen that the rotor proposed in this embodiment based on the optimization of the position and number of positioning holes 3 can effectively reduce the torque pulsation of the motor, while only slightly reducing part of the average torque. In the case of no slanted poles, there is no positioning hole, the positioning hole is added in the middle, and the center positioning hole is offset. The torque pulsation of the three is not much different, and the scheme proposed in this embodiment is compared with these three schemes. The motor torque pulsation is greatly reduced. In addition, opening holes at any angle or distance will cause the torque pulsation to increase, so the position of the hole does have an impact on the performance of the motor.

[0080] It is easy for those skilled in the art to understand that, under the premise of no conflict, the above-mentioned advantageous methods can be freely combined and superimposed.

[0081] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention shall be included in the protection scope of the present invention. The above are only preferred embodiments of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and variations can be made without departing from the technical principles of the present invention, and these improvements and variations should also be regarded as the protection scope of the present invention.

Claims

1. A rotor structure, comprising a rotor core unit (1) divided into multiple sections in the axial direction, each of the rotor core units (1) being provided with a plurality of magnetic steel slots (2), each of the magnetic steel slots (2) being provided with magnets (7), characterized in that: Adjacent rotor core units (1) are connected in a staggered manner in the circumferential direction; The rotor core unit (1) is provided with a plurality of positioning hole groups (3); when the rotor structure rotates counterclockwise, along the radial direction of the rotor core unit (1), the first positioning hole group (3) is correspondingly provided on the first side (21) of the center line of the magnetic steel slot (2); Or the rotor structure rotates clockwise, and along the radial direction of the rotor core unit (1), the second side (22) of the center line of the magnetic steel slot (2) is correspondingly provided with the positioning hole group (3).

2. The rotor structure according to claim 1, characterized in that: The positioning hole group (3) comprises a plurality of positioning through holes (301), the plurality of positioning through holes (301) being arranged along the circumference of the rotor core unit (1), and adjacent rotor core units (1) being connected with one positioning through hole (301) staggered therebetween.

3. The rotor structure according to claim 2, characterized in that: The number of the positioning through holes (301) is m, the number of segments of the rotor structure is n, and the number m and the number n satisfy: m=n.

4. The rotor structure according to claim 2, characterized in that: A line connecting the center of the positioning through hole (301) and the center of the rotor core unit (1) is a first straight line, and a line connecting the center of an adjacent positioning through hole (301) and the center of the rotor core unit (1) is a second straight line. An angle θ is provided between the first straight line and the second straight line, and the angle θ is 1°. The staggered angle between adjacent rotor core units (1) is 1°.

5. The rotor structure according to claim 4, characterized in that: The positioning hole group (3) comprises eight positioning through holes (301), the eight positioning through holes (301) are arranged at intervals, and the distance from the center of each positioning through hole (301) to the center of the rotor core unit (1) is the same; the rotor structure is segmented into eight rotor core units (1), and the staggered angle between the first rotor core unit (1) and the eighth rotor core unit (1) is 7°.

6. The rotor structure according to claim 2, characterized in that: A magnetic isolation bridge (4) is provided between a positioning through hole (301) close to the magnetic steel slot (2) and the magnetic steel slot (2); a vertical distance between an outer circle of the positioning through hole (301) and a circumferential outer side of the magnetic steel slot (2) is a width of the magnetic isolation bridge (4); the width is L, and the width L satisfies: 0.5 mm ≤ L ≤ 1 mm.

7. The rotor structure according to claim 2, characterized in that: Adjacent positioning through holes (301) are arranged tangentially, or adjacent positioning through holes (301) are arranged intersectingly, or adjacent positioning through holes (301) are arranged at intervals.

8. The rotor structure according to any one of claims 1 to 7, characterized in that: In the radial direction of the rotor core unit (1), the magnetic steel slot (2) is in a straight line shape, and the positioning hole group (3) is located on the radial outside of the magnetic steel slot (2); or the magnetic steel slot (2) is in a V-shape, and the positioning hole group (3) is located in the opening of the magnetic steel slot (2); or the magnetic steel slot (2) is in a U-shape, and the positioning hole group (3) is located in the opening of the magnetic steel slot (2).

9. The rotor structure according to claim 8, characterized in that: The magnetic steel slot (2) is a multi-layer slot structure, and in the radial direction of the rotor core, the positioning hole group (3) is close to the outermost magnetic steel slot (2).

10. A motor, comprising a rotor structure, characterized in that: The rotor structure is the rotor structure according to any one of claims 1 to 9.

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