Rotor assembly and electric machine

Abstract

The application discloses a rotor assembly and a motor, wherein the rotor assembly comprises: a rotor core and a plurality of permanent magnets, the rotor core is provided with an axle hole and a plurality of installation grooves, the plurality of installation grooves are arranged at intervals along the circumferential direction of the axle hole, and each installation groove extends from the axle hole to the outer circumferential wall of the rotor core; and the plurality of permanent magnets are arranged in the plurality of installation grooves one by one, each permanent magnet comprises a plurality of magnet portions arranged in sequence along the extension direction of the installation groove, and one of the two adjacent magnet portions of the permanent magnet is deflected relative to the other so that the end faces opposite to each other are arranged at a preset angle. The rotor assembly can effectively reduce the cogging torque and the ripple torque, so that the motor runs more stably, the vibration and noise of the motor are further reduced, the process difficulty and cost in manufacturing are also reduced, and the performance of the motor is improved.

Description

Technical Field

[0001] This invention relates to the field of motor technology, and more specifically, to a rotor assembly and a motor. Background Technology

[0002] In the existing technology, the magnetic bridges of the rotor assembly are completely disconnected. When the permanent magnets are axially segmented and offset, the manufacturing process is difficult and costly, which increases production costs and affects the performance of the motor, leaving room for improvement. Summary of the Invention

[0003] The present invention aims to at least partially solve one of the aforementioned technical problems in the prior art. To this end, the present invention proposes a rotor assembly that effectively reduces cogging torque and ripple torque, resulting in smoother motor operation, further reducing motor vibration and noise, and also reducing manufacturing difficulty and cost, thereby improving motor performance.

[0004] The present invention also proposes a motor having the above-described rotor assembly.

[0005] According to an embodiment of the present invention, a rotor assembly includes: a rotor core having a shaft hole and a plurality of mounting slots, the plurality of mounting slots being arranged circumferentially spaced along the shaft hole, each mounting slot extending from the shaft hole to the outer peripheral wall of the rotor core; and a plurality of permanent magnets, each of the plurality of permanent magnets being disposed one-to-one in the plurality of mounting slots, each of the permanent magnets including a plurality of magnet portions arranged sequentially along the extension direction of the mounting slot, wherein one of two adjacent magnet portions of the permanent magnet is deflected relative to the other so that their opposing end faces are arranged at a predetermined angle.

[0006] According to an embodiment of the present invention, the rotor assembly can effectively reduce cogging torque and ripple torque, making the motor run more smoothly, further reducing motor vibration and noise, and also reducing manufacturing process difficulty and cost, thereby improving motor performance.

[0007] In addition, the rotor assembly according to the embodiments of the invention may also have the following additional technical features:

[0008] According to some embodiments of the present invention, the preset angle is less than 60°.

[0009] According to some embodiments of the present invention, the preset angle is greater than 0° and less than 30°.

[0010] According to some embodiments of the present invention, in the three adjacent magnetic portions of the permanent magnet, the magnetic portion located in the middle is deflected in a first direction relative to the magnetic portion located on the outside, and the magnetic portion located on the inside is deflected in a second direction opposite to the first direction relative to the magnetic portion located in the middle, so that the end faces of the three adjacent magnetic portions that are opposite to each other are arranged at the preset angle.

[0011] According to some embodiments of the present invention, the plurality of magnetic portions of the permanent magnet include a first magnetic portion and a second magnetic portion, wherein the outer end face of the second magnetic portion is opposite to the inner end face of the first magnetic portion and arranged at the preset angle, wherein the center line of the first magnetic portion extends radially along the shaft hole, and the center line of the second magnetic portion extends obliquely relative to the radial direction of the shaft hole.

[0012] According to some embodiments of the present invention, the first side of the outer end face of the second magnet portion abuts against the first side of the inner end face of the first magnet portion.

[0013] According to some embodiments of the present invention, the plurality of magnet portions of the magnet portion further include a third magnet portion, wherein the outer end face of the third magnet portion is opposite to the inner end face of the second magnet portion and arranged at the preset angle, wherein the second side of the outer end face of the third magnet portion abuts against the second side of the inner end face of the second magnet portion; and / or, the center line of the third magnet portion is arranged parallel to the center line of the first magnet portion.

[0014] According to some embodiments of the present invention, the mounting groove includes a first side wall and two opposing second side walls, wherein the outer ends of the second side walls and the first side walls are connected by a transition wall, the transition wall extending from the inside to the outside toward the centerline of the mounting groove.

[0015] According to some embodiments of the present invention, the outer contour of the rotor core has an axisymmetric structure, and the center lines of the plurality of mounting slots divide the outer contour into multiple segments, each segment of the outer contour including multiple connected arcs.

[0016] According to another aspect of the present invention, an electric motor includes a rotating shaft and the rotor assembly described above, wherein the rotating shaft engages with the shaft hole.

[0017] According to some embodiments of the present invention, the rotor assembly includes a plurality of rotor assemblies stacked along the axial direction of the rotating shaft, wherein, in two adjacent rotor assemblies, the positions of a plurality of permanent magnets in one rotor assembly correspond one-to-one with the positions of a plurality of permanent magnets in the other rotor assembly and are staggered.

[0018] According to some embodiments of the present invention, in two adjacent rotor assemblies, the angle between the line connecting the midpoints of the same end face of the two permanent magnets at corresponding positions and the central axis of the permanent magnet is 3°-8°.

[0019] According to some embodiments of the present invention, in the plurality of rotor assemblies, the plurality of permanent magnets corresponding to the positions are arranged in a third-order staggered manner. Attached Figure Description

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

[0021] Figure 2 This is a schematic diagram of the structure of a motor according to an embodiment of the present invention.

[0022] Figure label:

[0023] Motor 100, rotor assembly 10, rotor core 1, shaft hole 11, mounting groove 12, first side wall 121, second side wall 122, transition wall 123, permanent magnet 2, first magnet part 21, second magnet part 22, third magnet part 23, rotating shaft 20, end cover 30. Detailed Implementation

[0024] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0025] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0026] like Figure 1 and Figure 2 As shown, the rotor assembly of this embodiment is applicable to a motor. Furthermore, this motor is widely used in the home appliance industry.

[0027] like Figure 1As shown, the tangentially built-in rotor assembly can use adjacent permanent magnets connected in parallel to provide magnetic flux. With this magnetic concentration capability, the air gap magnetic flux density of the motor can be significantly improved, making the motor more efficient, smaller in size, lighter in weight, and enabling the motor to have maximum torque and higher power density, thus improving the motor performance.

[0028] Furthermore, during the motor manufacturing process, by arranging permanent magnets in segments with offset, cogging torque and ripple torque can be effectively reduced, resulting in smoother motor operation.

[0029] In the prior art, the rotor assembly consists of a rotor core and multiple permanent magnets. The elongated permanent magnets extend radially along the rotor core. The rotor core and the rotor yoke are set independently, and there is a 1mm gap between the rotor core and the rotor yoke to reduce magnetic flux leakage in the rotor yoke. The rotor yoke is then fixed with an interference fit to the motor shaft so that the rotor assembly can be assembled onto the motor.

[0030] Because in the existing technology, the magnetic bridges of the rotor assembly are completely disconnected, the manufacturing process is more difficult and costly when the permanent magnets are axially segmented and offset, which increases production costs and affects the performance of the motor.

[0031] To this end, this embodiment of the invention designs a rotor assembly 10 in which a permanent magnet 2 is divided into multiple magnet parts, and one of two adjacent magnet parts is deflected relative to the other. Therefore, the magnet parts are offset on the rotor core 1, which can effectively reduce cogging torque and ripple torque, making the motor 100 run more smoothly, further reducing the vibration and noise of the motor 100, and also reducing the manufacturing process difficulty and cost, thereby improving the performance of the motor 100.

[0032] The following is for reference. Figures 1-2 The rotor assembly 10 according to an embodiment of the present invention is described.

[0033] The rotor assembly 10 according to an embodiment of the present invention may include: a rotor core 1 and a plurality of permanent magnets 2.

[0034] like Figure 1 As shown, the rotor core 1 has a shaft hole 11 and multiple mounting slots 12. The rotor core 1 is fixed to the rotating shaft 20 of the motor 100 by an interference fit through the shaft hole 11, so that the rotor assembly 10 can be assembled onto the motor 100. Multiple permanent magnets 2 are mounted on the rotor core 1 through the multiple mounting slots 12 provided on the rotor core 1.

[0035] Furthermore, multiple mounting slots 12 are arranged circumferentially along the shaft hole 11, with each mounting slot 12 extending from the shaft hole 11 toward the outer peripheral wall of the rotor core 1.

[0036] In other words, a plurality of mounting slots 12 are evenly arranged radially along the circumference on the rotor core 1. For example, the mounting slots 12 can extend radially along the shaft hole 11 or extend obliquely relative to the radial direction of the shaft hole 11. One end of the mounting slot 12 is close to the shaft hole 11 in its extension direction, and the other end is close to the outer peripheral wall of the rotor core 1.

[0037] It should be noted that the permanent magnets 2 can be individually molded first, and then the multiple molded permanent magnets 2 can be correspondingly installed into the multiple mounting slots 12 of the rotor core 1. Of course, magnetic powder can also be directly injected into the multiple mounting slots 12 of the rotor core 1 to form permanent magnets 2 in the mounting slots 12. For example, the principle of injection molding can be used to mix magnetic powder with binder and then produce permanent magnets 2 through injection molding.

[0038] In this configuration, multiple permanent magnets 2 are disposed one-to-one within multiple mounting slots 12. In other words, the shape of the permanent magnets 2 can be similar to the shape of the mounting slots 12, and the mounting slots 12 determine the mounting arrangement of the permanent magnets 2. Each permanent magnet 2 includes multiple magnet parts arranged sequentially along the extension direction of the mounting slot 12. The permanent magnet 2 can be divided into multiple segments arranged sequentially along the extension direction of the mounting slot 12, with each segment being a magnet part.

[0039] In the permanent magnet 2, for any two adjacent magnet parts, one of the magnet parts is deflected relative to the other magnet part, so that the opposite end faces of the two adjacent magnet parts can be arranged at a preset angle.

[0040] In other words, in the permanent magnet 2, any two adjacent magnet parts are offset from each other. In other words, the permanent magnet 2 is composed of several magnet parts that are offset from each other. Therefore, when the permanent magnet 2 is set on the rotor core 1, the magnet parts are offset on the rotor core 1, which can effectively reduce cogging torque and ripple torque, making the motor 100 run more smoothly, further reducing the vibration and noise of the motor 100, and also reducing the manufacturing process difficulty and cost, and improving the performance of the motor 100.

[0041] According to the rotor assembly 10 of the present invention, the rotor assembly 10 can effectively reduce cogging torque and ripple torque, making the motor 100 run more smoothly, further reducing the vibration and noise of the motor 100, and also reducing the manufacturing process difficulty and cost, thereby improving the performance of the motor 100.

[0042] Furthermore, the mounting slot 12 can also be divided into multiple slot segments, with the magnet part of each permanent magnet 2 correspondingly located in the multiple slot segments of the corresponding mounting slot 12.

[0043] In other words, after the permanent magnet 2 is installed in the mounting slot 12, each slot segment corresponds to a magnet part of the permanent magnet 2. In the mounting slot 12, for any two adjacent slot segments, one of the slot segments is deflected relative to the other slot segment so that the opposing walls of the two adjacent slot segments can be arranged at a preset angle.

[0044] In some embodiments, the multiple segments of the mounting slot 12 may be connected sequentially to facilitate the opening of the mounting slot. In other embodiments, the multiple segments of the mounting slot 12 may also be arranged separately to facilitate the positioning and installation of the permanent magnet 2.

[0045] Furthermore, in the permanent magnet 2, the angle between the opposing end faces of one of two adjacent magnet sections relative to the other is β, where β is less than 60°. When the angle between the opposing end faces of one of two adjacent magnet sections is greater than 60°, the permanent magnet 2 occupies too much installation space in the circumferential direction after being installed on the rotor core 1, which is not conducive to the arrangement of other permanent magnets 2 on the rotor core 1.

[0046] Furthermore, in the permanent magnet 2, the angle β between the opposite end faces of one of the two adjacent magnet parts relative to the other magnet part can be greater than 0° and less than 30°.

[0047] When the angle β between the opposite end faces of one of two adjacent magnet parts is 0°, one of the two adjacent magnet parts does not deflect relative to the other magnet part, thus failing to achieve the effect of reducing cogging torque and ripple torque.

[0048] Optionally, the angle β between the opposite end faces of two adjacent magnet sections can be 5°, 15°, or 25°. Therefore, this avoids excessive circumferential space occupied by the permanent magnet 2 after it is installed on the rotor core 1, making the overall structure of the permanent magnet 2 more reasonable, while ensuring sufficient offset between adjacent magnet sections. This effectively reduces cogging torque and ripple torque, resulting in smoother operation of the motor 100, further reducing vibration and noise, and improving the performance of the motor 100.

[0049] In some embodiments, refer to Figure 1In the permanent magnet 2, among three adjacent magnet sections, the middle magnet section is deflected in a first direction relative to the outer magnet section, thereby allowing the two adjacent magnet sections to be offset from each other. The inner magnet section is deflected in a second direction opposite to the first direction relative to the middle magnet section, thereby allowing all three adjacent magnet sections to be offset from each other, so that the end faces of each pair of adjacent magnet sections are arranged at a predetermined angle.

[0050] In other words, any three adjacent magnet sections of permanent magnet 2 are arranged in an "S" shape. Therefore, this avoids the permanent magnet 2 occupying too much installation space in the circumferential direction after it is installed on the rotor core 1, making the overall structure of permanent magnet 2 more reasonable while ensuring that there is sufficient offset between two adjacent magnet sections.

[0051] Furthermore, by arranging the permanent magnets 2 in this manner, multiple magnets on the rotor assembly 10 can be offsetly arranged, thereby effectively reducing cogging torque and ripple torque, making the motor 100 run more smoothly, further reducing the vibration and noise of the motor 100, and also reducing the manufacturing process difficulty and cost, thus improving the performance of the motor 100.

[0052] In other embodiments, among the three adjacent magnet portions of the permanent magnet 2, the middle magnet portion is deflected in a first direction relative to the outer magnet portions, thereby allowing the two adjacent magnet portions to be offset from each other. The inner magnet portion is deflected in the first direction relative to the middle magnet portion, thereby allowing the three adjacent magnet portions to be offset from each other, so that the opposite end faces of the three adjacent magnet portions are arranged at a predetermined angle.

[0053] By adopting this arrangement, the permanent magnets 2 can also achieve offset arrangement of multiple magnet parts on the rotor assembly 10, thereby effectively reducing cogging torque and ripple torque, making the motor 100 run more smoothly, further reducing the vibration and noise of the motor 100, and also reducing the manufacturing process difficulty and cost, and improving the performance of the motor 100.

[0054] like Figure 1 As shown, the permanent magnet 2 includes a first magnet portion 21 and a second magnet portion 22. The first magnet portion 21 and the second magnet portion 22 are arranged adjacent to each other. The first magnet portion 21 and the second magnet portion 22 have a rectangular structure, and their outer end faces and inner end faces are parallel to each other and arranged perpendicularly to their respective center lines.

[0055] In this configuration, the outer end face of the second magnet portion 22 is opposite to the inner end face of the first magnet portion 21, and the outer end face of the second magnet portion 22 and the inner end face of the first magnet portion 21 are arranged at a preset angle. That is, the angle between the extension direction of the outer end face of the second magnet portion 22 and the extension direction of the inner end face of the first magnet portion 21 is a preset angle, thereby causing the extension direction of the center line of the second magnet portion 22 to be offset to one side by a preset angle relative to the extension direction of the center line of the first magnet portion 21.

[0056] Therefore, the second magnet part 22 is offset from the first magnet part 21. After the second magnet part 22 and the first magnet part 21 are installed on the rotor core 1, the cogging torque and ripple torque can be effectively reduced, making the motor 100 run more smoothly, further reducing the vibration and noise of the motor 100, and also reducing the manufacturing process difficulty and cost, thus improving the performance of the motor 100.

[0057] The centerline of the first magnet portion 21 extends radially along the shaft hole 11, while the centerline of the second magnet portion 22 extends radially at an inclination relative to the shaft hole 11. Therefore, the second magnet portion 22 is offset from the first magnet portion 21. After the second magnet portion 22 and the first magnet portion 21 are mounted on the rotor core 1, cogging torque and ripple torque are effectively reduced, resulting in smoother operation of the motor 100. This further reduces the vibration and noise of the motor 100, lowers the manufacturing process difficulty and cost, and improves the performance of the motor 100.

[0058] Reference Figure 1 The first side of the outer end face of the second magnet portion 22 abuts against the first side of the inner end face of the first magnet portion 21, making the overall structure of the permanent magnet 2 more compact and avoiding the permanent magnet 2 occupying too much installation space. Furthermore, the included angle between the first side of the outer end face of the second magnet portion 22 and the inner end face of the first magnet portion 21 can be a preset angle. This facilitates the processing and manufacturing of the rotor assembly 10.

[0059] Furthermore, the first side of the outer end face of the second magnet portion 22 abuts against the first side of the inner end face of the first magnet portion 21. That is, the second magnet portion 22 is offset relative to the first magnet portion 21 towards the first side of the center line of the first magnet portion 21. Therefore, the first side of the outer end face of the second magnet portion 22 abuts against the first side of the inner end face of the first magnet portion 21, and the outer end face of the second magnet portion 22 and the inner end face of the first magnet portion 21 can form an angle of a preset angle.

[0060] like Figure 1As shown, the multiple magnet sections of the magnet section also include a third magnet section 23. The third magnet section 23 can also be a rectangular structure. The outer end face and the inner end face of the third magnet section 23 are parallel to each other and are arranged perpendicular to the center line of the third magnet section 23.

[0061] The outer end face of the third magnet portion 23 is opposite to the inner end face of the second magnet portion 22 and arranged at a preset angle. That is, the angle between the extension direction of the outer end face of the third magnet portion 23 and the extension direction of the inner end face of the second magnet portion 22 is a preset angle, so that the extension direction of the center line of the third magnet portion 23 is offset to the second side by a preset angle relative to the extension direction of the center line of the second magnet portion 22.

[0062] Therefore, the third magnet part 23 and the second magnet part 22 are offset from each other. After the second magnet part 22 and the first magnet part 21 are installed on the rotor core 1, the cogging torque and ripple torque can be effectively reduced, making the motor 100 run more smoothly, further reducing the vibration and noise of the motor 100, and also reducing the manufacturing process difficulty and cost, thus improving the performance of the motor 100.

[0063] The preset angle between the outer end face of the third magnet part 23 and the inner end face of the second magnet part 22 may be different from the preset angle between the outer end face of the second magnet part 22 and the inner end face of the first magnet part 21.

[0064] Furthermore, the second side of the outer end face of the third magnet portion 23 abuts against the second side of the inner end face of the second magnet portion 22. That is, the third magnet portion 23 is offset relative to the second magnet portion 22 towards the second side of the center line of the second magnet portion 22. Therefore, the second side of the outer end face of the third magnet portion 23 abuts against the second side of the inner end face of the second magnet portion 22, and the outer end face of the third magnet portion 23 and the inner end face of the second magnet portion 22 can form an angle of a preset angle.

[0065] In summary, the first magnet portion 21 deflects relative to the second magnet portion 22 toward the first end of the center line of the second magnet portion 22, and the third magnet portion 23 deflects relative to the second magnet portion 22 toward the second end of the center line of the second magnet portion 22.

[0066] In other words, the adjacent first magnet section 21, second magnet section 22, and third magnet section 23 of the permanent magnet 2 are arranged in an "S" shape. Therefore, the permanent magnet 2 avoids occupying too much installation space in the circumferential direction after being installed on the rotor core 1, making the overall structure of the permanent magnet 2 more reasonable while ensuring that there is sufficient offset between two adjacent magnet sections.

[0067] When the preset angle between the outer end face of the third magnet portion 23 and the inner end face of the second magnet portion 22 is the same as the preset angle between the outer end face of the second magnet portion 22 and the inner end face of the first magnet portion 21. Furthermore, the center line of the third magnet portion 23 is arranged parallel to the center line of the first magnet portion 21, making the overall structure of the rotor assembly 10 more reasonable and facilitating the processing and manufacturing of the rotor assembly 10.

[0068] In other words, the centerline of the third magnet section 23 is offset to the second side by a predetermined angle relative to the centerline of the second magnet section 22. The centerline of the first magnet section 21 is offset to the first side by the same predetermined angle relative to the centerline of the second magnet section 22. This makes the centerline of the third magnet section 23 parallel to the centerline of the first magnet section 21. Therefore, the overall structure of the rotor assembly 10 is more reasonable, and the rotor assembly 10 is easier to process and manufacture.

[0069] Reference Figure 1 The mounting groove 12 has a first side wall 121 and a second side wall 122. The first side wall 121 is the side wall near the outer peripheral wall of the rotor core 1, and the second side wall 122 are the side walls on both sides in the extension direction of the first side wall 121. The two second side walls 122 are arranged opposite to each other to stably limit the permanent magnet 2 in the mounting groove 12.

[0070] The outer end of the second side wall 122 and the first side wall 121 are connected by a transition wall 123, which extends from the inside out toward the center line of the mounting groove 12. Therefore, the mounting groove 12 is modified by the transition wall 123.

[0071] Reference Figure 1 The outer contour of the rotor core 1 is an axisymmetric structure. The center lines of multiple mounting slots 12 divide the outer contour into multiple segments. Each segment of the outer contour includes multiple connected arcs, so as to optimize the outer arc of the rotor core 1 through multiple connected arcs.

[0072] In some embodiments, the radii of curvature of the multiple connected arcs of each outer contour line are the same. In other embodiments, the radii of curvature of the multiple connected arcs of each outer contour line are different or partially different. The radii of curvature of the multiple connected arcs can be specifically set according to the injection mold, process requirements, etc.

[0073] Furthermore, when multiple rotor cores 1 are arranged sequentially along the rotating shaft 20, the rotor cores 1 can be arranged more conveniently according to their outer contour lines, ensuring that the permanent magnets 2 on the multiple rotor cores 1 can be offset in the axial direction. Therefore, the cogging torque and ripple torque can be effectively reduced, making the motor 100 run more smoothly, further reducing the vibration and noise of the motor 100, and also reducing the manufacturing process difficulty and cost, thus improving the performance of the motor 100.

[0074] A specific embodiment of the rotor assembly 10 is described below with reference to the accompanying drawings.

[0075] like Figure 1 As shown, the rotor assembly 10 includes a rotor core 1 and a plurality of permanent magnets 2.

[0076] Each permanent magnet 2 is divided into multiple segments arranged sequentially in its extending direction, and each segment is a magnet part. Furthermore, the rotor core 1 has multiple mounting slots 12, each mounting slot 12 being divided into multiple connected slot segments in its extending direction, and each slot segment corresponding to a magnet part. Multiple permanent magnets 2 are correspondingly disposed within multiple mounting slots 12, and the permanent magnets 2 have the same shape as the mounting slots 12, with each slot segment corresponding to a magnet part of the permanent magnet 2.

[0077] After the permanent magnet 2 is installed on the rotor core 1, the magnet part located near the outer peripheral surface of the rotor core 1 in the extending direction of the permanent magnet 2 is the first magnet part, and the magnet part located near the shaft hole 11 is the nth magnet part. The extending direction of the center line of the first magnet part, the third magnet part, and the (2n-1)th magnet part is parallel to the radial direction of the shaft hole 11 at the position where the center line of the first magnet part is located.

[0078] Furthermore, the extension direction of the centerline of the second magnet part, the fourth magnet part, and the 2nth magnet part is offset by a certain angle from the radial direction of the shaft hole 11 at the position of the centerline of the first magnet part. The offset angle is a preset angle.

[0079] Furthermore, the first side of the outer end face of the 2nth magnet part abuts against the first side of the inner end face of the 2n-1th magnet part. The second side of the inner end face of the 2nth magnet part abuts against the second side of the outer end face of the 2n+1th magnet part.

[0080] Therefore, after the permanent magnet 2 is installed on the rotor core 1, the multiple magnet parts are offset and arranged on the rotor core 1, which can effectively reduce the cogging torque and ripple torque, making the motor 100 run more smoothly, further reducing the vibration and noise of the motor 100, and also reducing the manufacturing process difficulty and cost, and improving the performance of the motor 100.

[0081] Furthermore, the groove of the mounting slot 12 is closed to ensure the stability of the permanent magnet 2 during installation.

[0082] Another specific embodiment of the rotor assembly 10 is described below with reference to the accompanying drawings.

[0083] like Figure 1 As shown, the rotor assembly 10 includes a rotor core 1 and ten permanent magnets 2. The rotor core 1 has a cylindrical structure, and the ten permanent magnets 2 are evenly distributed on the rotor core 1.

[0084] Furthermore, each permanent magnet 2 is divided into three segments arranged sequentially in its extending direction, with each segment being a magnet part. Ten mounting slots 12 are provided on the rotor core 1. Each mounting slot 12 is divided into three connected segments in its extending direction, with each segment corresponding to a magnet part. The ten permanent magnets 2 are correspondingly arranged within the ten mounting slots 12. The permanent magnets 2 have the same shape as the mounting slots 12, and each slot segment corresponds to a magnet part of the permanent magnet 2.

[0085] After the permanent magnets 2 are installed on the rotor core 1, the magnet portion located near the outer circumference of the rotor core 1 along the extending direction of the permanent magnets 2 is designated as the first magnet portion 21, and the magnet portion located near the shaft hole 11 is designated as the third magnet portion 23. The extending direction of the center lines of the first magnet portion 21 and the third magnet portion 23 is parallel to the radial direction of the shaft hole 11 at the location of the center line of the first magnet portion 21. Furthermore, the center lines of the first magnet portions 21 of all ten permanent magnets 2 pass through the center of the shaft hole 11 on the rotor core 1, thus dividing the rotor core 1 into ten equal parts.

[0086] Furthermore, the second magnet portion 22 is disposed between the first magnet portion 21 and the third magnet portion 23. The extension direction of the centerline of the second magnet portion 22 is offset from the radial direction of the shaft hole 11 at the location of the centerline of the first magnet portion by a certain angle. The offset angle is a preset angle. Optionally, the preset angle is 15°.

[0087] Furthermore, the first magnet portion 21, the second magnet portion 22, and the third magnet portion 23 can be rectangular in structure. The first side of the outer end face of the second magnet portion 22 abuts against the first side of the inner end face of the first magnet portion 21, and a predetermined angle is formed between the inner and outer end faces. The second side of the inner end face of the second magnet portion 22 abuts against the second side of the outer end face of the third magnet portion 23, and the same predetermined angle is formed between the inner and outer end faces.

[0088] Therefore, after the permanent magnet 2 is installed on the rotor core 1, the first magnet part 21, the second magnet part 22 and the third magnet part 23 are offset on the rotor core 1, which can effectively reduce the cogging torque and ripple torque, making the motor 100 run more smoothly, further reducing the vibration and noise of the motor 100, and also reducing the manufacturing process difficulty and cost, and improving the performance of the motor 100.

[0089] According to another embodiment of the present invention, the motor 100 includes a rotating shaft 20 and a rotor assembly 10 described in the above embodiments. The rotating shaft 20 is interference-fitted with the shaft hole 11 so that the rotor assembly 10 can be stably installed in the motor 100.

[0090] Specifically, such as Figure 2 As shown, multiple rotor assemblies 10 are provided inside the motor 100. The motor 100 can be installed by stacking the multiple rotor assemblies 10 sequentially along the axial direction of the shaft 20.

[0091] When installing two adjacent rotor assemblies 10, it is first necessary to make the positions of multiple permanent magnets 2 in one rotor assembly 10 correspond one-to-one with the positions of multiple permanent magnets 2 in the other rotor assembly 10. After the correspondence, the permanent magnets 2 are arranged to be staggered from each other in the axial direction.

[0092] Therefore, the permanent magnets 2 inside the motor 100 are offset in the axial direction of the motor 100, which can effectively reduce cogging torque and ripple torque, making the motor 100 run more smoothly, further reducing the vibration and noise of the motor 100, and also reducing the manufacturing process difficulty and cost, thereby improving the performance of the motor 100.

[0093] Furthermore, refer to Figure 2 In two adjacent rotor assemblies 10, the angle between the line connecting the midpoints of the same end face of the two permanent magnets 2 at corresponding positions and the central axis of the permanent magnet 2 is α, where 3°≤α≤8°.

[0094] Optionally, the angle between the line connecting the midpoints of the same end face of the two permanent magnets 2 and the central axis of the permanent magnet 2 can be 4°, 5°, 6° and 7°, to ensure that there is sufficient offset between the two adjacent permanent magnets 2, so that it can effectively reduce cogging torque and ripple torque, making the motor 100 run more smoothly, further reducing the vibration and noise of the motor 100, and improving the performance of the motor 100.

[0095] Reference Figure 2In multiple rotor assemblies 10, multiple permanent magnets 2 corresponding to the positions are staggered in the third direction so that the permanent magnets 2 are offset in the third direction. Therefore, the cogging torque and ripple torque can be effectively reduced, making the motor 100 run more smoothly, greatly reducing the vibration and noise of the motor 100, and improving the performance of the motor 100.

[0096] According to the embodiments of the present invention, the motor 100, by adopting the above-described rotor assembly 10, has lower processing costs, smoother operation, and better performance.

[0097] A specific embodiment of the motor 100 is described below with reference to the accompanying drawings.

[0098] like Figure 2 As shown, the motor 100 includes a rotating shaft 20, multiple rotor assemblies 10, and an end cover 30. During the installation of the motor 100, the first rotor assembly 10 is first installed and fixed to the rotating shaft 20 in a set position through the shaft hole 11. Then, the second rotor assembly 10 is installed and fixed to the rotating shaft 20 through the shaft hole 11, and the angle between the line connecting the midpoint of one end face of the permanent magnet 2 of the second rotor assembly 10 and the midpoint of the same end face of the first rotor assembly 10 and the axis of the motor 100 is α, where α can be 4°, 5°, 6°, or 7°. Similarly, the third, fourth, and nth rotor assemblies 10 are installed and fixed to the rotating shaft 20, and the angle between the line connecting the midpoint of one end face of the permanent magnet 2 of the nth rotor assembly 10 and the midpoint of the same end face of the (n-1)th rotor assembly 10 and the axis of the motor 100 is α.

[0099] Furthermore, after all rotor assemblies 10 are installed and fixed on the shaft 20, the axial sides of the motor 100 are fixed by the end caps 30.

[0100] In some embodiments, after all rotor assemblies 10 are mounted and secured on the shaft 20, the rotor of the motor 100 may also be secured by plastic coating.

[0101] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0102] Other constructions of the motor 100 are already known to those skilled in the art and are not described in detail here.

[0103] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0104] Although embodiments of the invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.

Claims

1. An electric motor, characterized in that, include: A rotating shaft and rotor assembly, wherein the rotating shaft mates with a shaft hole; The rotor assembly includes: A rotor core having a shaft hole and a plurality of mounting slots, the plurality of mounting slots being arranged circumferentially spaced along the shaft hole, each mounting slot extending from the shaft hole toward the outer peripheral wall of the rotor core; Multiple permanent magnets are disposed in multiple mounting slots in a one-to-one correspondence. Each permanent magnet includes multiple magnet parts arranged sequentially along the extension direction of the mounting slot. One of two adjacent magnet parts of the permanent magnet is deflected relative to the other so that their opposing end faces are arranged at a preset angle. The rotor assembly comprises multiple rotor assemblies, which are stacked along the axial direction of the shaft. In two adjacent rotor assemblies, the positions of the permanent magnets in one rotor assembly correspond one-to-one with the positions of the permanent magnets in the other rotor assembly, and they are staggered. In two adjacent rotor assemblies, the angle between the line connecting the midpoints of the same end face of the two permanent magnets at corresponding positions and the central axis of the permanent magnet is 3°-8°. In the three adjacent magnet sections of the permanent magnet, the magnet section located in the middle is deflected in a first direction relative to the magnet section located on the outside, and the magnet section located on the inside is deflected in a second direction opposite to the first direction relative to the magnet section located in the middle, so that the end faces of the three adjacent magnet sections that are opposite to each other are arranged at the preset angle.

2. The motor according to claim 1, characterized in that, The preset angle is less than 60°.

3. The motor according to claim 2, characterized in that, The preset angle is greater than 0° and less than 30°.

4. The motor according to any one of claims 1-3, characterized in that, The permanent magnet comprises a first magnet portion and a second magnet portion, wherein the outer end face of the second magnet portion is opposite to the inner end face of the first magnet portion and arranged at the preset angle. The centerline of the first magnet portion extends radially along the shaft hole, while the centerline of the second magnet portion extends radially obliquely relative to the shaft hole.

5. The motor according to claim 4, characterized in that, The first side of the outer end face of the second magnet part abuts against the first side of the inner end face of the first magnet part.

6. The motor according to claim 4, characterized in that, The plurality of magnet portions of the magnet section also includes a third magnet portion, the outer end face of which is opposite to the inner end face of the second magnet portion and arranged at the preset angle. Wherein, the second side of the outer end face of the third magnet part abuts against the second side of the inner end face of the second magnet part; and / or, the center line of the third magnet part is arranged parallel to the center line of the first magnet part.

7. The motor according to claim 1, characterized in that, The mounting groove includes a first side wall and two opposing second side walls. The outer end of the second sidewall and the first sidewall are connected by a transition wall, which extends from the inside to the outside toward the center line of the mounting groove.

8. The motor according to claim 1, characterized in that, The outer contour of the rotor core has an axisymmetric structure, and the center lines of the multiple mounting slots divide the outer contour into multiple segments, each segment of the outer contour including multiple connected arcs.

9. The motor according to claim 1, characterized in that, In the plurality of rotor assemblies, the permanent magnets corresponding to the positions are arranged in a third-order staggered manner.

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