Rotor structure and motor with same

Abstract

The utility model provides a rotor structure and a motor with the rotor structure, the rotor structure comprises rotor iron core units which are divided into a plurality of sections in the axial direction, each rotor iron core unit is provided with a plurality of magnetic steel grooves, magnets are arranged in the magnetic steel grooves, and adjacent rotor iron 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 enables the magnetic lines of force of the motor to be distorted 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 utility model belongs to motor technical field, concretely relates to a rotor structure and motor with the rotor structure. BACKGROUND

[0002] In the electromagnetic design field, the method for reducing motor vibration and noise includes reasonable pole-slot matching and winding selection, optimization of pole arc coefficient, opening auxiliary slots in the stator, increasing air gap width, etc. For built-in motors, the method of optimizing magnetic barrier angle and changing the direction of magnetic lines can also be used. Stator skewing or rotor skewing can reduce tooth harmonic caused by tooth slot effect and greatly reduce the motor's tooth slot torque and ripple torque, thereby reducing the motor's vibration and noise. In the case of fixed electromagnetic scheme and the stator and rotor having been opened, skewing is the most economical and effective method for reducing tooth slot torque and torque ripple. However, the stator skewing process is complex in mass production, and it is difficult to skew the laminated core. After skewing, it is not easy to automatically embed the wire. Compared with the stator skewing, the segmented rotor skewing is obviously a better choice.

[0003] The related technology discloses a segmented rotor skewing structure for a permanent magnet synchronous motor. In order to reduce the torque ripple of a specific order, the segmented rotor has different stagger angles and axial lengths. This technology does not consider staggering the rotor core at different angles without re-opening the mold. If this design is to be implemented, a rotor punching sheet needs to be specially designed for each segmented rotor core in order to stagger at different angles, which greatly increases the cost of the mold. The related technology discloses a segmented skewing rotor structure for a vehicle-mounted permanent magnet synchronous motor. A plurality of key grooves are arranged on the outer diameter of the rotor punching sheet in the circumferential direction, and a flat key groove is opened on the shaft in the axial direction. During assembly, the key grooves are overlapped to realize segmented rotor skewing. This design increases the relative width of the air gap, thereby reducing the rated torque of the motor and changing the performance of the motor. UTILITY MODEL CONTENTS

[0004] The utility model provides a rotor structure and motor with the rotor structure, can solve for the motor of having opened the mold, the design scheme of motor is fixed, to the optimization method of torque ripple and harmonic loss, will influence motor performance's technical problem.

[0005] The utility model provides a rotor structure, including in the axial direction direction is divided into many rotor core units, every rotor core unit all is equipped with a plurality of magnetic steel groove, the magnetic body is provided with in the magnetic steel groove, its characterized in that: adjacent rotor core unit is connected in the circumferential direction staggeredly;

[0006] A plurality of positioning hole groups are arranged on the rotor core unit, the rotor structure is counterclockwise rotation, along the radial direction of the rotor core unit, the first side of the magnetic steel groove center line is provided with the positioning hole group correspondingly;

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

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

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

[0010] In some embodiments, the line connecting the center of the positioning through hole and the center of the rotor core unit is a first straight line, the line connecting the center of the adjacent positioning through hole and the center of the rotor core unit is a second straight line, the first straight line and the second straight line have an included angle θ, the angle of the included 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, 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, the positioning through hole close to the magnetic steel slot has a magnetic isolation bridge between the positioning through hole and the magnetic steel slot, 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, the width is L, and the width L satisfies: 0.5mm≤L≤1mm.

[0013] In some embodiments, the adjacent positioning through holes are arranged tangentially, or the adjacent positioning through holes are arranged intersectingly, or the adjacent positioning through holes are arranged at intervals.

[0014] In some embodiments, in the radial direction of the rotor core unit, the magnetic steel slot is in a linear shape, and the positioning hole group is located on the radial outer side 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, and the rotor structure is the above-mentioned rotor structure.

[0017] The rotor structure and the motor having the same have the following beneficial effects:

[0018] The setting position of the positioning hole group is related to the rotation direction of the rotor, and the setting of the positioning hole group causes the distortion of the magnetic force line of the motor according to the rotation direction of the motor, the purpose of which is to affect the magnetic force line distribution as much as possible, the torque ripple of the motor can be reduced through the setting, and each rotor core unit in the embodiment is provided in this way, on the one hand, the skew pole of the rotor can be realized through a set of molds without the need of replacing the molds, and on the other hand, the back electromotive force harmonic and the torque ripple of the motor can be reduced by changing the setting position of the positioning hole group, the performance of the motor will not be reduced, compared with the general skew pole motor, the torque ripple and the cogging torque generated after the rotor structure of the embodiment is applied are smaller. BRIEF DESCRIPTION OF DRAWINGS

[0019] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings needed to be used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings in the following description are only exemplary, and for those skilled in the art, other implementation drawings can be obtained according to the provided drawings without creative labor.

[0020] Figure 1 It is a schematic view of the rotor structure of the embodiment of the utility model;

[0021] Figure 2 It is a schematic view of the included angle θ of the embodiment of the utility model;

[0022] Figure 3 It is a schematic view of the width L of the magnetic isolation bridge of the embodiment of the utility model;

[0023] Figure 4 It is a detailed enlarged view of the rotor structure of the embodiment of the utility model;

[0024] Figure 5 It is a schematic view of the linear magnetic steel slot of the embodiment of the utility model;

[0025] Figure 6 It is a schematic view of the U-shaped magnetic steel slot of the embodiment of the utility model;

[0026] Figure 7 It is a schematic view of the multi-layer magnetic steel slot of the embodiment of the utility model;

[0027] Figure 8 It is a torque and torque ripple simulation diagram of the motor without the positioning through hole of scheme one;

[0028] Figure 9 Torque and torque ripple simulation diagram of the motor with the positioning through hole arranged on the center line of the magnetic steel slot of scheme two;

[0029] Figure 10 Torque and torque ripple simulation diagram of the motor with the positioning through hole deviated from the symmetric center of scheme three;

[0030] Figure 11 Torque and torque ripple simulation diagram of the motor with the positioning hole group of the embodiment;

[0031] Figure 12 No-load magnetic force line distribution nephogram of the motor of scheme one;

[0032] Figure 13 Load magnetic force line distribution nephogram of the motor of scheme one;

[0033] Figure 14 No-load magnetic force line distribution nephogram of the motor of scheme two;

[0034] Figure 15 Load magnetic force line distribution nephogram of the motor of scheme two;

[0035] Figure 16 No-load magnetic force line distribution nephogram of the motor of scheme three;

[0036] Figure 17 Load magnetic force line distribution nephogram of the motor of scheme three;

[0037] Figure 18 No-load magnetic force line distribution nephogram of the motor of scheme four;

[0038] Figure 19 Load magnetic force line distribution nephogram of the motor of scheme four;

[0039] Figure 20 Schematic view of the motor of the embodiment of the utility model.

[0040] The drawings: 1 - rotor core unit;2 - magnetic steel slot;21 - the first side of the magnetic steel slot center line;22 - the second side of the magnetic steel slot center line;3 - positioning hole group;301 - positioning through hole;4 - magnetic bridge;5 - stator;6 - magnet. DETAILED DESCRIPTION

[0041] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. The description of the at least one exemplary embodiment is merely illustrative in nature and in no way should be taken as any limitation on the present application and its application or uses. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative labor fall within the scope of the present application.

[0042] In the description of the present application, it should be understood that the orientation words such as "front, back, up, down, left, right", "horizontal, vertical, perpendicular, horizontal" and "top, bottom" and the like indicate the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and in the absence of contrary description, these orientation words do not indicate and imply that the indicated device or element must have a particular orientation or be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the scope of protection of the present application; the orientation words "inner, outer" refer to the inner and outer of the contour of each component itself.

[0043] For the convenience of description, spatial relative terms such as "on", "above", "upper surface", "upper" and the like can be used herein to describe the spatial positional relationship of one device or feature with respect to other devices or features as shown in the drawings. It should be understood that the spatial relative terms are intended to include different orientations in use or operation in addition to the orientation of the device described in the drawings. For example, if the device in the drawings is inverted, the device described as "above" or "on" other devices or structures will be positioned "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below" orientations. The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein are interpreted accordingly.

[0044] In addition, it should be noted that the use of "first", "second" and the like to define parts is only for the convenience of distinguishing the corresponding parts, and the above words have no special meaning unless otherwise stated, and therefore cannot be understood as limiting the scope of protection of the present application.

[0045] For reference Figures 1 to 4As shown, according to the embodiment of the utility model, provide a rotor structure, including in axial direction is divided into many rotor core unit 1, every rotor core unit 1 all be equipped with a plurality of magnetic steel groove 2, magnetic steel groove 2 is provided with magnet, the adjacent rotor core unit 1 is connected in the circumferential direction with staggered position;Rotor core unit 1 is equipped with a plurality of positioning hole group 3, rotor structure counterclockwise rotation, along the radial direction of rotor core unit 1, the first side 21 of magnetic steel groove 2 center line is correspondingly provided with positioning hole group 3;Or rotor structure clockwise rotation, along the radial direction of rotor core unit 1, the second side 22 of magnetic steel groove 2 center line is correspondingly provided with positioning hole group 3.

[0046] It is worth mentioning that, in the circumferential direction of the rotor core unit 1, the first side 21 of the magnetic steel groove 2 center line refers to the left side, that is, the positioning hole group 3 is close to the left side of the magnetic steel groove 2; the second side 22 of the magnetic steel groove 2 center line refers to the right side, that is, the positioning hole group 3 is close to the right side of the magnetic steel groove 2.

[0047] Specifically, compared with the motor no-load operation, when the motor is in load operation, the armature reaction of the stator 5 causes the air gap magnetic field to be distorted, thereby dragging the rotor to rotate, so the magnetic lines of force on the rotor are equivalent to being distributed along the rotation direction of the motor. When the motor runs in the counterclockwise direction (generally this is the running mode), there is a certain phase difference between the stator 5 and the magnetic lines of force of the rotor from the perspective of the magnetic lines of force. In order to guide the direction of the magnetic lines of force, the positioning hole group 3 is arranged on the left side of each magnetic steel groove 2, which changes the direction of the magnetic lines of force. When the motor runs in the clockwise direction, the positioning hole group 3 is arranged on the right side of each magnetic steel groove 2, which also changes the direction of the magnetic lines of force in this state. Each rotor core unit 1 is arranged in this way, and the rotor core units 1 are connected with staggered position. In this embodiment, the adjacent rotor core units 1 are connected by a screw rod, which is connected by penetrating the positioning hole group 3, thereby achieving the connection of the rotor core units 1 with staggered position.

[0048] In this embodiment, the arrangement position of the positioning hole group 3 is related to the rotation direction of the rotor. According to the rotation direction of the motor, the arrangement of the positioning hole group 3 causes the magnetic lines of force of the motor to be distorted, and the purpose is to affect the distribution of the magnetic lines of force as much as possible. Through this arrangement, the torque ripple of the motor can be reduced. Moreover, each rotor core unit 1 in this embodiment is arranged in this way. On the one hand, the rotor skew can be realized by using a set of molds without the need to replace the molds. On the other hand, by changing the arrangement position of the positioning hole group 3, the back electromotive force harmonic and the torque ripple of the motor can be reduced, which will not cause the performance of the motor to decrease. Compared with the general skew motor, the torque ripple and the cogging torque generated after the rotor structure of this embodiment is applied are smaller.

[0049] As a specific embodiment, 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 arranged at a position where the rotor magnetic force line is greatly distorted, so as to optimize the motor air gap magnetic density waveform and more easily realize the multi-section skew pole of the rotor.

[0050] As a specific embodiment, each rotor core unit 1 is formed by stacking rotor punching sheets, and then the adjacent rotor core units 1 are rotated to be staggered by a certain angle, and the screw rod is inserted into the positioning hole group 3 to connect the rotor core units 1.

[0051] Referring to Figures 1 to 4 As shown in the figure, 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 circumference of the rotor core unit 1, and the adjacent rotor core units 1 are connected by staggering one positioning through hole 301.

[0052] Specifically, the staggering of 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 arranging the screw rod, and the positioning hole group 3 corresponding to each magnetic steel groove 2 is 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, and if more than three rotor core units 1 are arranged, the above-mentioned staggered connection mode is adopted.

[0053] In the embodiment, not only the setting position of the positioning hole group 3 is optimized, but also the number of positioning through holes 301 of the positioning hole group 3 is optimized. Compared with the conventional positioning through hole 301 arranged on each rotor core unit 1, the setting angle of the positioning through hole 301 of the adjacent rotor core unit 1 is offset to realize the skew pole connection. In the embodiment, the number of positioning through holes 301 is optimized, so that the setting position and number of the positioning hole group 3 on each rotor core unit 1 are the same, and the skew pole connection can still be realized. The skew connection mode can effectively disperse stress. The design of the positioning through hole 301 enables the rotor core unit 1 to be accurately aligned during assembly, avoids the connection offset between the rotor core units 1 due to improper alignment, and reduces the performance problems caused by assembly errors. Moreover, compared with the traditional skew slot or skew pole design, the skew connection mode with the positioning hole group 3 can simplify the manufacturing process and reduce the production cost. Since the mold does not need to be re-opened, the existing design can be adjusted to achieve better motor performance. In summary, the optimization of 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. The effective connection mode helps to reduce energy loss and improve the overall working efficiency of the motor.

[0054] It is worth noting that the specific skew pole mode in the embodiment is prior art, which will not be described here.

[0055] For reference Figures 1 to 4 As shown in the figure, the number of positioning through holes 301 is m, and the number of rotor structure segments is n. The number m and the number n satisfy: m = n.

[0056] In the 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 positioning through holes 301 and the number of rotor structure segments are correspondingly arranged. This can ensure that each rotor core unit 1 can be accurately connected in skew, forming a uniformly distributed skew structure, thereby effectively reducing torque ripple and vibration. Moreover, it can avoid opening useless positioning through holes 301, simplify the assembly process, improve the assembly efficiency and accuracy, and standardize the connection between each rotor core unit 1, thereby reducing the performance difference caused by improper assembly.

[0057] For reference Figures 1 to 4 As shown in the figure, the line connecting the center of the positioning through hole 301 and the center of the rotor core unit 1 is the first straight line, the line connecting the center of the adjacent positioning through hole 301 and the center of the rotor core unit 1 is the second straight line, the first straight line and the second straight line have an included angle θ, the angle of the included angle θ is 1°, and the skew angle between the adjacent rotor core units 1 is 1°.

[0058] In the embodiment, the torque ripple in the operation of the motor can be effectively reduced by the 1° offset angle. The torque ripple is a nonlinear phenomenon caused by uneven magnetic field distribution in the operation of the motor. The small angle offset can make the magnetic field distribution more uniform, thereby reducing the torque ripple. Compared with other complex offset or skewed slot designs, the 1° offset angle is easier to implement in the manufacturing process, can simplify the production process and reduce the cost, and the design does not need to change the basic shape and size of the rotor core unit 1, so the compactness of the motor structure can be maintained. It should be noted that the offset angle of 1° in the embodiment is set in combination with the number of rotor structure segments and the skew angle.

[0059] For reference Figures 1 to 4 As shown in FIG. 6, the positioning hole group 3 includes eight positioning through holes 301, which 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 offset angle between the first rotor core unit 1 and the eighth rotor core unit 1 is 7°.

[0060] In the embodiment, for the structure with a large number of rotor core segments, if the diameter of each positioning through hole 301 is too large, it will also affect the stiffness of the rotor core as a whole. In the embodiment, the number of segments is large, but the diameter of each positioning through hole 301 is relatively small, so that the connection of the multiple rotor core units 1 can be realized. 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, which helps to improve the assembly accuracy, ensure the accurate alignment between the rotor core units 1, and reduce the performance problems caused by assembly errors. The precise offset connection and uniform distribution of the positioning through holes 301 in the embodiment can ensure that the connection between the rotor core units 1 is more stable, and improve the reliability and durability of the motor.

[0061] For reference Figures 1 to 4 As shown in FIG. 7, the positioning through hole 301 near the magnetic steel slot 2 has a magnetic isolation bridge 4 between the positioning through hole 301 and the magnetic steel slot 2. The vertical distance between the outer circle of the positioning through hole 301 and the circumferential outside of the magnetic steel slot 2 is the width of the magnetic isolation bridge 4, which is L. The width L satisfies: 0.5mm≤L≤1mm.

[0062] 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 arranged 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. Therefore, in the embodiment, 0.5mm≤L≤1mm, which can not only optimize the direction of the magnetic force line, but also ensure the stiffness of the rotor core unit 1.

[0063] In this embodiment, the function of the magnetic bridge 4 is to artificially create a smaller magnetic flux path, so that the magnetic flux is more concentrated and the magnetic density is larger. Due to the nonlinear characteristics of the magnetic circuit, the magnetic resistance at this position will also become very large. By changing the path of the magnetic flux, the effect of reducing torque ripple can be achieved. In theory, the smaller the magnetic bridge, the better. However, the design of the magnetic bridge needs to balance between reducing magnetic leakage and ensuring the mechanical strength of the rotor. Under high-speed rotation, the rotor is subjected to a large centrifugal force, so it needs to have sufficient mechanical strength to resist this force and avoid material buckling or breaking, and to avoid the possibility of magnetic bridge rupture 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 as the distance between the positioning through hole 301 closest to the magnetic steel slot 2 and the magnetic steel slot 2, and is independent of the structure of the positioning hole group 3.

[0064] As a specific implementation, the positioning through hole 301 closest to the magnetic steel slot 2 has the greatest impact on the performance of the motor, so 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 rod to pass through the positioning hole to achieve the inclined pole of the rotor, and the minimum diameter thereof should not be less than the minimum diameter of the screw rod, which is 4mm. Correspondingly, the minimum diameter of the positioning through hole 301 should be greater than 4mm to ensure that the screw rod can be installed into the positioning through hole 301. The maximum diameter of the positioning through hole 301 can not be limited, and the screw rod can be fixed by glue injection. The diameters of the remaining positioning through holes 301 can not be limited.

[0065] For reference Figures 1 to 4 As shown in the figure, the adjacent positioning through holes 301 are tangentially arranged, or the adjacent positioning through holes 301 are intersectingly arranged, or the adjacent positioning through holes 301 are spaced apart.

[0066] Specifically, the center-to-center distance between the multiple positioning through holes 301 and the rotor core unit 1 is the same, which is R, the radius of the positioning hole is the same, which is r, and the spacing angle between the positioning through holes 301 is the included angle θ. For motors with different pole-slot combinations, the relationship between the included angle θ between the positioning through holes and the pole-slot combination is θ= where Z is the number of stator slots 5, and 2p is the number of rotor pole pairs. The positioning through holes 301 can be intersecting, tangent, or spaced apart, and their states are related to the three forms, the spacing angle θ between the positioning through holes 301, and the center-to-center distance R and the radius r. If r< , the positioning through holes 301 are intersecting, if r= , the positioning through holes 301 are tangent, and if r> , the positioning through holes 301 are spaced apart.

[0067] Specifically, the optimal inclined pole angle of the motor is Where Z represents the number of stator slots (5), 2p represents the number of rotor pole pairs, and the least common multiple of the number of motor pole slots is 48. Therefore, the optimal skew angle of this motor is 7.5°. To achieve multi-segment skew of the rotor, this embodiment provides multiple continuous through holes to place the screw. Based on positional considerations, the positioning through holes 301 are connected to each other. Each group of positioning holes 3 consists of 8 adjacent positioning through holes 301, with each adjacent positioning hole spaced 1° apart. The center of each positioning through hole 301 is equidistant from the center of the rotor.

[0068] In this embodiment, the positioning through-hole 301 closest to the magnet slot 2 has the greatest impact on the number of magnetic lines of force, while the positioning through-hole 301 farther away has a smaller impact on the magnetic lines of force. Therefore, the three states of tangency, relative, and separation have little impact on the electromagnetic performance of the motor itself. However, when the rotor core stack height is constant, and the number of rotor core segments is greater, more positioning holes are required. If there are too many positioning through-holes 301, the holes will intersect, while if there are fewer segments, the holes will be separated. By adjusting the relative positions (tangency, 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 settings (tangency, intersection, or separation) have different degrees of impact on the magnetic lines of force, and can be adjusted according to specific motor design requirements.

[0069] As a specific implementation, the distance R from each positioning through hole 301 to the rotor core unit 1 may also be different, but it must be ensured that the positioning through hole 301 with the largest distance R from the rotor core unit 1 is spaced more than 1 mm from the outer circle of the rotor core unit 1.

[0070] As a specific implementation, the illustration of this embodiment only shows that the positioning through hole 301 is circular. In other embodiments, its shape can also be triangular, quadrilateral, or even polygonal.

[0071] See also Figure 1 , Figures 5 to 7 As shown, in the radial direction of the rotor core unit 1, the magnet slot 2 is in the shape of a straight line, and the positioning hole group 3 is located on the radial outer side of the magnet slot 2; or the magnet slot 2 is in the shape of a V, and the positioning hole group 3 is located in the opening of the magnet slot 2; or the magnet slot 2 is in the shape of a U, and the positioning hole group 3 is located in the opening of the magnet slot 2.

[0072] Specifically, for different shapes of the magnetic steel slot 2, the width of the magnetic isolation bridge 4 needs to meet 0.5mm≤L≤1mm, but in order to ensure the stiffness of the rotor core unit 1, the distance from each shape of the magnetic steel slot 2 to the outer circle of the rotor core unit 1 is different. For the magnetic steel slot 2 in the shape of a character, the positioning through hole 301 is located on the left side of the magnetic steel slot 2 in the shape of a character of each pole, the width of the magnetic isolation bridge 4 between the positioning through hole 301 and the magnetic steel slot 2 should meet 0.5mm~1mm, and the distance between the positioning through hole 301 and the outer circle of the rotor is greater than 1mm. For the V-shaped rotor, 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 distance between the positioning through hole 301 and the outer circle of the rotor is greater than 1mm; for the U-shaped rotor, the distance between the positioning through hole 301 and the left rib magnetic steel slot 2 of the U-shaped rotor is 0.5~1mm, and the distance between the positioning through hole 301 and the outer circle of the rotor is greater than 1mm.

[0073] For reference Figure 7 As shown in the figure, 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.

[0074] As a specific embodiment, the rotor of the embodiment is 8-pole, the magnetic steel is inserted into the magnetic barrier according to the rule of NSNS along the circumference, and the rotor core is usually locked by a screw, so that the positioning through hole 301 is added to the rotor core to put in the screw, and the magnetic steel slot 2 and a positioning hole group 3 are provided for each pole, that is, the magnetic steel slot 2 can be provided with multiple layers, but according to the demand of the inclined pole of the rotor core unit 1, only one positioning hole group 3 is provided for each pole, and in other embodiments, according to the performance demand of the motor, multiple positioning hole groups 3 can be provided for each pole.

[0075] For reference Figure 20 As shown in the figure, a motor includes a rotor structure, and the rotor structure is the above-mentioned rotor structure.

[0076] As an electromagnetic conversion device, the energy of the motor is mainly stored in the air gap. When the rotor rotates to cause the change of the energy of the air gap, part of the magnetic field energy in the air gap will be converted into mechanical energy to realize the conversion of mechanical and electrical energy. The magnetic field energy in the air gap is provided by the stator 5 and the rotor. The magnetic motive force generated by the winding of the stator 5 can be calculated by the winding function method. For the magnetic motive force of the rotor, if the rotor is taken as the reference system, the magnetic motive force generated by the rotor is (assuming that the rotor has a pair of poles):

[0077]

[0078] If the stator 5 is taken as the reference system, then:

[0079]

[0080] Where, F r is the rotor magnetic motive force, υ is the harmonic number, Fυ is the rotor position angle, and θ is the current angle. The permanent magnet rotor generates a harmonic-rich magnetomotive force. For a three-phase permanent magnet synchronous motor, the harmonic magnetomotive force adversely affects the operation of the motor.

[0081] According to the conventional positioning hole 301 arrangement, the embodiment specifically relates to three rotor structures for comparison. Taking a motor with a V-shaped rotor magnetic pole as an example, a first scheme is that no positioning hole 301 is arranged on the rotor core. The torque ripple and magnetic path trend are as shown in Figure 8 、 Figure 12 and Figure 13 . A second scheme is that a positioning hole 301 is arranged on the center line of the magnetic steel slot 2, and one positioning hole 301 is further arranged on each side of the positioning hole 301. The torque ripple and magnetic path trend are as shown in Figure 9 、 Figure 14 and Figure 15 . A third scheme is that the positioning hole is offset from the symmetry center by 1°. The torque ripple and magnetic path trend are as shown in Figure 10 、 Figure 16 and Figure 17 . The torque ripple and magnetic path trend of the embodiment are as shown in Figure 11 、 Figure 18 and Figure 19 . The average torque and torque ripple of the motor with different positioning hole 301 arrangement positions are as shown in the following figures:

[0082]

[0083] It can be seen that the rotor proposed in the embodiment based on the positioning hole 301 arrangement position and the number of holes can effectively reduce the torque ripple of the motor, and only slightly reduce part of the average torque. The torque ripples of the three schemes of no positioning hole, adding a positioning hole in the middle, and offsetting the center positioning hole are not much different. Compared with the three schemes, the scheme proposed in the embodiment greatly reduces the torque ripple of the motor. In addition, any angle or distance of the hole will cause the torque ripple to rise, so the hole position has an impact on the performance of the motor.

[0084] It is easy for those skilled in the art to understand that the above advantageous modes can be freely combined and superimposed without conflict.

[0085] The above merely is the preferred embodiment of the present application, and does not limit the present application, and any modification, equivalent replacement and improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application. The above is merely the preferred embodiment of the present application, and it should be pointed out that, for ordinary skilled in the art, without departing from the technical principle of the present application, a number of improvements and modifications can be made, and these improvements and modifications shall be considered as the protection scope of the present application.

Claims

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

2. The rotor structure of claim 1, wherein The positioning hole group (3) comprises a plurality of positioning through holes (301), and the plurality of positioning through holes (301) are arranged in the circumferential direction of the rotor core unit (1), and the adjacent rotor core units (1) are connected with one positioning through hole (301) staggered.

3. The rotor structure of claim 2, wherein The number of the positioning through holes (301) is m, the number of the rotor structure is n, and the number m and the number n satisfy: m=n.

4. The rotor structure of claim 2, wherein The center line of the positioning through hole (301) and the center line of the rotor core unit (1) are a first straight line, the center line of the adjacent positioning through hole (301) and the center line of the rotor core unit (1) are a second straight line, the first straight line and the second straight line have an included angle θ, the angle of the included angle θ is 1°, and the staggered angle between the adjacent rotor core units (1) is 1°.

5. The rotor structure of claim 4, wherein The positioning hole group (3) comprises eight positioning through holes (301), the eight positioning through holes (301) are arranged at intervals, 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 of claim 2, wherein The positioning through hole (301) close to the magnetic steel slot (2) and the magnetic steel slot (2) have a magnetic isolation bridge (4), 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), the width is L, and the width L satisfies: 0.5mm≤L≤1mm.

7. The rotor structure of claim 2, wherein The adjacent positioning through holes (301) are arranged tangentially, or the adjacent positioning through holes (301) are arranged intersectingly, or the adjacent positioning through holes (301) are arranged at intervals.

8. The rotor structure of any one of claims 1 to 7, wherein, In the radial direction of the rotor core unit (1), the magnetic steel slot (2) is in a linear shape, and the positioning hole group (3) is located on the radial outer side 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 of claim 8, wherein The magnetic steel slot (2) is a multi-layer slot structure, and the positioning hole group (3) is close to the outermost magnetic steel slot (2) in the radial direction of the rotor core.

10. An electric machine comprising a rotor structure, characterized in that The rotor structure is any one of the rotor structures in claims 1-9.

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