Rotor and electric motor

Abstract

Provided in the embodiments of the present application are a rotor and an electric motor. The rotor comprises a rotor core and permanent magnets. The rotor core is provided with a plurality of permanent magnet slot groups in the circumferential direction of the rotor core. Each permanent magnet slot group comprises at least two permanent magnet slots arranged in a V-shape with an opening facing outward. The two permanent magnet slots are symmetrical about a first axis of the rotor. One end of each permanent magnet slot is close to the first axis, and the other end thereof is close to a side wall of the rotor core. The permanent magnets are disposed in the permanent magnet slots. Each permanent magnet comprises a main body portion and permanent magnet end portions arranged at two ends of the main body portion in the direction of width thereof, the thickness of the permanent magnet end portions being greater than the thickness of the main body portion. The direction of width of the permanent magnets is perpendicular to the axial direction of the rotor. In the rotor provided in the embodiments of the present application, the thickness of the permanent magnet end portions of the permanent magnets is greater than the thickness of the main body portions in the middle, thereby improving the demagnetization resistance of the permanent magnets at the permanent magnet end portions, reducing the magnetic reluctance of the permanent magnets, increasing the d-axis inductance, reducing a three-phase short-circuit current and improving the continuous operating capability of the electric motor under fault conditions such as a three-phase short circuit.

Description

A rotor and motor

[0001] Cross-references to related applications

[0002] This application is based on and claims priority to Chinese Patent Application No. 202411936015.9, filed on December 26, 2024, the entire contents of which are incorporated herein by reference. Technical Field

[0003] This application relates to the field of motor technology, and more particularly to a rotor and a motor. Background Technology

[0004] Compared with traditional motors, current permanent magnet synchronous motors have advantages such as simple structure, high efficiency, and good performance.

[0005] In related technologies, the magnets mounted on the rotor of a permanent magnet synchronous motor are prone to local demagnetization at the four corners of the magnets under high temperature and high current operating conditions. Demagnetization of the magnets can lead to motor damage, thereby affecting the operation of the motor drive system. Summary of the Invention

[0006] In view of this, embodiments of this application aim to provide a rotor and motor to improve the demagnetization resistance of magnets mounted on the rotor.

[0007] To achieve the above objectives, one aspect of this application provides a rotor, comprising:

[0008] The rotor core has multiple magnetic slot groups arranged circumferentially. Each magnetic slot group includes at least two magnetic slots arranged in a V-shape with the opening facing outward. The two magnetic slots are symmetrical about the first axis of the rotor. One end of the magnetic slot is close to the first axis, and the other end is close to the side wall of the rotor core.

[0009] A magnetic steel component is disposed in the magnetic steel groove. The magnetic steel component includes a main body and magnetic steel ends disposed at both ends of the main body along the width direction. The thickness of the magnetic steel ends is greater than the thickness of the main body.

[0010] The width direction of the magnet is perpendicular to the axial direction of the rotor.

[0011] In some embodiments, the first axis is the D-axis of the rotor.

[0012] In some embodiments, the magnet slot assembly includes two magnet slot units, each magnet slot unit including two magnet slots arranged in a V-shape with the opening facing outwards, and the two magnet slot units are spaced apart along the first axis.

[0013] In some embodiments, one of the magnet ends of the magnet component is close to the first axis, and the other magnet end is close to the sidewall of the rotor core. The main body is flush with the sidewall of the magnet ends at both ends along the thickness direction of the magnet component on one side, and a groove is formed on the other sidewall.

[0014] In some embodiments, the end of the magnet includes a connecting layer and at least two first blocks, two adjacent first blocks are connected by the connecting layer, and each first block is arranged along the width direction of the magnet.

[0015] In some embodiments, the main body includes a connecting layer and at least two second blocks, adjacent second blocks are connected by the connecting layer, and each second block is arranged along the width direction of the magnet.

[0016] In some embodiments, the dimension of the first segment in the width direction of the magnet is smaller than the dimension of the second segment in the width direction of the magnet.

[0017] In some embodiments, a connecting layer is provided between the end of the magnet and the main body.

[0018] In some embodiments, the connecting layer includes an insulating film and an insulating adhesive.

[0019] In some embodiments, the dimensions of each of the magnet ends in the width direction of the magnet part are smaller than the dimensions of the main body in the width direction of the magnet part.

[0020] In some embodiments, the magnet groove protrudes along the groove wall in the thickness direction of the magnet to form a protrusion, which matches the groove to limit the magnet in the width direction.

[0021] In some embodiments, magnetic isolation cavities are respectively provided at both ends of the magnetic steel groove along the width direction of the magnetic steel component. The magnetic isolation cavities are connected to the magnetic steel groove, and the groove walls of the magnetic steel groove along the width direction of the magnetic steel component limit the magnetic steel component in the width direction of the magnetic steel component.

[0022] Another aspect of this application provides an electric motor, including the rotor described in any of the preceding claims.

[0023] The rotor provided in this application embodiment arranges at least two magnet slots of the magnet slot group in a V-shape with the opening facing outwards. The magnet slots are symmetrical along the first axis of the rotor, such that the magnets disposed in the magnet slots have one end close to the first axis along the width direction and the other end close to the side wall of the rotor core. The thickness of the two magnet ends is greater than the thickness of the middle main body. Thus, the magnet ends disposed at both ends of the magnet slot in the width direction are close to the first axis and the side wall of the rotor core, respectively. On the one hand, the increased thickness of the magnet end close to the first axis can improve the demagnetization resistance of the magnets close to the first axis. On the other hand, the increased thickness of the magnet ends close to the side wall of the rotor core, that is, close to the air gap between the stator and rotor, can improve the demagnetization resistance of the magnets close to the rotor surface by increasing the thickness of the magnet ends in this part. Furthermore, the thickness of the main body is thinner than that of the magnet ends, which can reduce magnetic reluctance, increase D-axis inductance, reduce three-phase short-circuit current, and improve the continuous operation capability of the motor under fault conditions such as three-phase short circuit. Attached Figure Description

[0024] Figure 1 is a schematic diagram of the rotor provided in this application;

[0025] Figure 2 is a partial cross-sectional schematic diagram of the rotor provided in this application;

[0026] Figure 3 is a cross-sectional view of the rotor in this application on a section perpendicular to the axial direction;

[0027] Figure 4 is an enlarged view of point A in Figure 3;

[0028] Figure 5 is a structural schematic diagram of the magnet component of the rotor provided in this application.

[0029] Explanation of reference numerals in the attached drawings: 10. Rotor; 11. Rotor core; 11a. Magnet slot assembly; 11b. Magnet slot unit; 11c. Magnet slot; 11d. Protrusion; 11e. Magnetic isolation cavity; 11f. Magnetic barrier hole; 11g. Ventilation hole; 12. Magnet component; 12a. Groove; 121. Main body; 1211. Second segment; 122. Magnet end; 1221. First segment; 1222. Connecting layer; 13. Shaft; 14. Rotor pressure ring; s. First axis. Detailed Implementation

[0030] The embodiments of this application will be described in further detail below with reference to the accompanying drawings and examples. The following examples are used to illustrate this application, but should not be used to limit the scope of this application.

[0031] In the description of the embodiments of this application, it should be noted that the terms "center," "upper," "lower," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of this application 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 the embodiments of this application. In addition, the terms "first," "second," and "third," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0032] In the description of the embodiments of this application, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of this application based on the specific circumstances.

[0033] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the embodiments of this application. 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. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0034] Compared with traditional motors, current permanent magnet synchronous motors have advantages such as simple structure, high efficiency, and good performance.

[0035] In related technologies, the magnets mounted on the rotor of a permanent magnet synchronous motor are prone to local demagnetization at the four corners of the magnets under high temperature and high current operating conditions. Demagnetization of the magnets can lead to motor damage, thereby affecting the operation of the motor drive system.

[0036] Based on the above, a first aspect of this application provides a rotor 10, as shown in Figures 1 to 5. The rotor 10 includes a rotor core 11 and magnets 12. The rotor core 11 has a plurality of magnet slot groups 11a arranged circumferentially. Each magnet slot group 11a includes at least two magnet slots 11c arranged in a V-shape with their openings facing outwards. The two magnet slots 11c are symmetrical about a first axis s of the rotor 10. One end of each magnet slot 11c is close to the first axis s, and the other end is close to the sidewall of the rotor core 11. Magnets 12 are disposed in the magnet slots 11c. Each magnet 12 includes a main body 121 and magnet ends 122 disposed at both ends of the main body 121 along its width direction. The thickness of the magnet ends 122 is greater than the thickness of the main body 121. The width direction of the magnet 12 is perpendicular to the axial direction of the rotor 10.

[0037] It should be noted that the rotor 10 in this application is the rotor of a permanent magnet synchronous motor.

[0038] A permanent magnet synchronous motor (PMSM) is a synchronous motor that uses permanent magnets to generate a magnetic field. The rotor's speed is synchronized with the frequency of the current in the stator windings. The working principle of a PMSM is based on the interaction between the rotating magnetic field generated by the stator windings and the magnetic field generated by the permanent magnets on the rotor. The rotor is equipped with pre-magnetized permanent magnets, which generate a strong magnetic field when rotating, thus providing greater output torque. The motor's control system precisely regulates the current to ensure that the motor rotor rotates synchronously with the rotating magnetic field, maintaining a stable operating state.

[0039] The permanent magnets on the rotor are usually called magnets or magnet components.

[0040] In this application, "axial", "circumferential" and "radial" refer to the axial, circumferential and radial directions of the rotor 10, respectively. In the embodiments of this application, the axial, circumferential and radial directions of the rotor 10, the rotor core 11 and the motor are consistent.

[0041] It should be noted that the dimensions of different parts in the three directions are different in the same absolute coordinate system. Generally, the length, width and thickness of an object are determined according to the dimensions of the object extending in the three directions, with length > width > thickness.

[0042] In this embodiment, the length direction, thickness direction and width direction of the magnetic slot 11c and the magnetic component 12 are consistent, and the length direction of the magnetic component 12 is parallel to the axial direction of the rotor 10.

[0043] The rotor core 11 is provided with multiple magnetic slot groups 11a along the circumference, and the multiple magnetic slot groups 11a can be evenly distributed along the circumference.

[0044] It is understandable that one magnetic slot group 11a corresponds to one magnetic pole.

[0045] For example, the number of magnetic poles of rotor 10 can be two, three, four, five, six, eight, ten, or twelve, etc.

[0046] Each magnetic steel groove group 11a includes at least two magnetic steel grooves 11c arranged in a V-shape with the opening facing outwards. This means that a magnetic steel groove group 11a includes at least a V-shape formed by two magnetic steel groove groups 11a, wherein one end of the two magnetic steel grooves 11c is arranged adjacent to each other to form the bottom of the V-shape, and the other end forms the opening at the top of the V-shape. The width direction of the two magnetic steel grooves 11c has a certain included angle.

[0047] For example, the direction from the bottom to the top of the V-shaped magnet slot group 11a is parallel to the radial direction of the rotor 10.

[0048] It is understandable that the two magnetic slots 11c can be connected or not connected at the bottom of the V-shape, and no restriction is imposed here.

[0049] The two magnetic slots 11c are symmetrical about the first axis s of the rotor 10, wherein the first axis s passes through the central axis of the rotor 10.

[0050] As shown in Figures 3 and 4, the first axis s is denoted by s.

[0051] For example, the magnet slot 11c extends through both end faces of the rotor core 11 along the axial direction of the rotor core 11.

[0052] One end of the magnetic steel groove 11c is close to the first axis s, and the other end is close to the side wall of the rotor core 11. This means that the two ends of the magnetic steel groove 11c along its width direction are close to the first axis s and the outer side wall of the rotor core 11, respectively. The length direction of the magnetic steel groove 11c is parallel to the axial direction of the rotor 10.

[0053] The magnet component 12 includes a main body 121 and magnet ends 122 disposed at both ends of the main body 121 along the width direction, wherein the main body 121 can be connected to the magnet ends 122 by adhesive bonding.

[0054] For example, the main body 121 is connected to the magnet end 122 by insulating adhesive.

[0055] The thickness of the magnet end 122 is greater than the thickness of the main body 121, as shown in Figure 5. The thickness of the magnet end 122 is represented by b, and the thickness of the main body 121 is represented by c. Thus, the magnet ends 122, located at both ends of the width direction of the magnet slot 11c, are close to the first axis s and the side wall of the rotor core 11, respectively. On the one hand, the increased thickness of the magnet end 122 near the first axis s can improve the demagnetization resistance of the magnet 12 near the first axis s. On the other hand, the magnet 12 near the side wall of the rotor core 11, that is, near the air gap of the stator and rotor 10, can improve the demagnetization resistance of the magnet 12 near the surface of the rotor 10 by increasing the thickness of the magnet end 122 in this part. Furthermore, the thickness of the main body 121 is thinner than that of the magnet end 122, which can reduce magnetic reluctance, increase D-axis inductance, reduce three-phase short-circuit current, and improve the continuous operation capability of the motor under fault conditions such as three-phase short circuit.

[0056] For example, the magnetic steel component 12 includes a high-temperature resistant, high-performance permanent magnet material.

[0057] For example, the ratio of the thickness c of the main body 121 to the thickness b of the magnet end 122 ranges from 0.6 to 0.9.

[0058] For example, the ratio of the thickness c of the main body 121 to the thickness b of the magnet end 122 is 0.6, 0.65, 0.7, 0.75, 0.8, 0.85 or 0.9, etc., and is not limited here.

[0059] The rotor 10 provided in this embodiment of the application arranges at least two magnet slots 11c of the magnet slot group 11a in a V-shape with the opening facing outwards. The magnet slots 11c are symmetrical along the first axis s of the rotor 10, such that the magnets 12 disposed in the magnet slots 11c have their magnet end 122 at one end along the width direction close to the first axis s, and their magnet end 122 at the other end close to the side wall of the rotor core 11. The thickness of the two magnet end 122 is greater than the thickness of the middle main body 121. Thus, the magnet end 122 disposed at both ends of the width direction of the magnet slots 11c are close to the first axis s and the side wall of the rotor core 11, respectively. On the one hand, increasing the thickness of the magnet end 122 near the first axis s can improve the demagnetization resistance of the magnet 12 near the first axis s. On the other hand, the magnet 12 near the side wall of the rotor core 11, that is, near the air gap of the stator and rotor 10, can improve the demagnetization resistance of the magnet 12 near the surface of the rotor 10 by increasing the thickness of the magnet end 122 in this part. Furthermore, the thickness of the main body 121 is thinner than that of the magnet end 122, which can reduce magnetic resistance, increase D-axis inductance, reduce three-phase short-circuit current, and improve the continuous operation capability of the motor under fault conditions such as three-phase short circuit.

[0060] In some embodiments, the first axis s is the D-axis of the rotor 10.

[0061] It should be noted that the D-axis refers to the direct-axis, where the direction of the D-axis is the same as the direction of the magnetic field of any magnetic pole on rotor 10, i.e., parallel. The D-axis is the center line of any magnetic pole on rotor 10.

[0062] In the control of permanent magnet synchronous motors, in order to obtain control characteristics similar to those of DC motors, a coordinate system can be established on the rotor 10 of the motor. This coordinate system rotates synchronously with the rotor 10, and the direction of the magnetic field of any magnetic pole on the rotor 10 is taken as the D-axis.

[0063] It is understandable that the rotor 10 of the motor has multiple magnetic poles, each magnetic pole corresponds to a first axis s, namely the D axis, and each magnetic pole is distributed with a magnetic steel slot group 11a at a certain angle and symmetrical about the D axis.

[0064] Here, by setting the first axis s as the D axis of the rotor 10, the two magnet slots 11c of the magnet slot group 11a are symmetrical along the D axis, so that the magnet end 122 of the magnet piece 12 provided in the magnet slot 11c can have a certain thickness in the width direction near the D axis, thereby improving the anti-demagnetization performance of the magnet piece 12 near the D axis.

[0065] In other embodiments, the first axis s may also be an axis close to the D axis and having a certain angle with the D axis, which is not limited here.

[0066] In some embodiments, referring to Figures 3 and 4, the magnet slot assembly 11a includes two magnet slot units 11b. Each magnet slot unit 11b includes two magnet slots 11c arranged in a V-shape with their openings facing outwards. The two magnet slot units 11b are spaced apart along a first axis s.

[0067] In this embodiment, the magnetic steel groove group 11a includes two magnetic steel groove units 11b, and each magnetic steel groove unit 11b includes two magnetic steel grooves 11c arranged in a V-shape with the opening facing outward. That is, a magnetic steel groove group 11a includes four magnetic steel grooves 11c.

[0068] The two magnetic steel groove units 11b are spaced apart along the first axis s, meaning that the two pairs of V-shaped magnetic steel grooves 11c are spaced apart by a certain distance in the extension direction of the first axis s.

[0069] It should be noted that the two magnet slots 11c arranged in a V-shape with their openings facing outwards in each magnet slot unit 11b are symmetrical about the first axis s, and one end of each magnet slot 11c is close to the first axis s, while the other end is close to the side wall of the rotor core 11. Thus, in the magnet slot group 11a, the magnet slot 11c of the magnet slot unit 11b closer to the central axis is larger than the magnet slot 11c of the magnet slot unit 11b farther from the central axis, at least in the width direction.

[0070] Thus, by setting up a double-layer V-shaped magnetic steel groove 11c, the contact area between the magnetic steel component 12 and the air gap is increased, making it easier for magnetic flux to pass through the air gap, thereby improving the magnetic flux utilization rate.

[0071] In some embodiments, referring to Figures 4 and 5, one magnet end 122 of the magnet component 12 is close to the first axis s, and the other magnet end 122 is close to the sidewall of the rotor core 11. The main body 121 is flush with the sidewall of the magnet ends 122 at both ends along the thickness direction of the magnet component 12 on one side, and a groove 12a is formed on the other sidewall.

[0072] The main body 121 and the magnet ends 122 at both ends are flush with the sidewall of the magnet part 12 along the thickness direction. In other words, the sidewall of the magnet part 12 along the thickness direction is flat, which is more conducive to assembly. At the same time, it simplifies the structure of the magnet groove 11c and is more conducive to the processing of the magnet groove 11c.

[0073] It is understandable that, since the thickness of the main body 121 is less than the thickness of the magnet end 122, when the main body 121 and the magnet end 122 at both ends are flush with the side wall on one side along the thickness direction of the magnet part 12, a groove 12a will be formed on the other side wall.

[0074] In other embodiments, the two magnet ends 122 are not flush with the sidewalls on both sides of the main body 121 along the thickness direction, and grooves 12a are formed on each side. The grooves 12a on both sides can limit the movement with the groove wall of the magnet groove 11c, thereby improving the fixing effect of the magnet groove 11c on the magnet.

[0075] In some embodiments, referring to Figures 4 and 5, the magnet end 122 includes a connecting layer 1222 and at least two first blocks 1221. Two adjacent first blocks 1221 are connected by the connecting layer 1222, and each first block 1221 is arranged along the width direction of the magnet 12.

[0076] It should be noted that the connecting layer 1222 is made of insulating material. By dividing the magnet end 122 into at least two first blocks 1221 along the width direction, the eddy current loss of the magnet end 122 can be reduced.

[0077] It is understandable that the more first blocks 1221 there are, the smaller the eddy current loss at the magnet end 122. However, at the same time, the smaller the width of the first block 1221, the easier it is for the structural strength of the first block 1221 to decrease, and the easier it is for the first block 1221 to be damaged in physical structure.

[0078] As shown in Figure 5, the dimension of the first segment 1221 in the width direction of the magnet 12 is represented by d.

[0079] For example, the dimension d of the first segment 1221 in the width direction of the magnet 12 ranges from 3mm to 8mm.

[0080] For example, the dimension d of the first segment 1221 in the width direction of the magnet 12 is 3mm, 3.5mm, 4mm, 4.5mm, 5mm, 5.5mm, 6mm, 6.5mm, 7mm, 7.5mm or 8mm, etc., and there is no limitation here.

[0081] It is understandable that, within the same magnet end 122, the dimensions of each first segment 1221 in the width direction of the magnet part 12 may be the same or different.

[0082] Here, by dividing the magnet end 122 into at least two first blocks 1221 along the width direction, the eddy current loss of the magnet 12 at the magnet end 122 can be reduced, thereby reducing the temperature of the magnet 12 at the magnet end 122 during motor operation and reducing the probability of the magnet 12 demagnetizing at the magnet end 122 due to high temperature.

[0083] In some embodiments, referring to Figures 4 and 5, the main body 121 includes a connecting layer 1222 and at least two second blocks 1211. Two adjacent second blocks 1211 are connected by the connecting layer 1222, and each second block 1211 is arranged along the width direction of the magnet 12.

[0084] The arrangement of each second segment 1211 along the width direction of the magnet 12 means that the second segment 1211 is formed by cutting the main body 121 along the width direction.

[0085] It should be noted that the connecting layer 1222 is made of insulating material. By dividing the main body 121 into at least two second blocks 1211 along the width direction, the eddy current loss of the main body 121 of the magnet 12 can be reduced.

[0086] As shown in Figure 5, the dimension of the second block 1211 in the width direction of the magnet 12 is represented by e.

[0087] For example, the dimension e of the second segment 1211 in the width direction of the magnet 12 ranges from 3mm to 12mm.

[0088] For example, the dimension e of the second segment 1211 in the width direction of the magnet 12 is 3mm, 4mm, 5mm, 6mm, 7mm, 8mm, 9mm, 10mm, 11mm or 12mm, etc., and there is no limitation here.

[0089] It is understandable that, within the same main body 121, the dimensions of each second sub-block 1211 in the width direction of the magnet 12 may be the same or different.

[0090] In this embodiment, by dividing the main body 121 into at least two second blocks 1211 along the width direction, the eddy current loss of the magnet 12 in the main body 121 can be reduced, thereby reducing the temperature of the magnet 12 in the main body 121 during motor operation and reducing the probability of the magnet 12 demagnetizing in the main body 121 due to high temperature.

[0091] In some embodiments, the two magnet ends 122 of the magnet component 12 each include a connecting layer 1222 and at least two first blocks 1221, and the main body 121 includes a connecting layer 1222 and at least two second blocks 1211. By dividing the magnet ends 122 and the main body 121 of the magnet component 12 into at least two first blocks 1221 and at least two second blocks 1211 along the width direction, the eddy current loss of the entire magnet component 12 can be reduced, thereby reducing the overall temperature of the magnet component 12 during motor operation and reducing the probability of demagnetization of the magnet component 12 due to high temperature.

[0092] For example, each of the two magnet ends 122 of the magnet component 12 includes a connecting layer 1222 and two first blocks 1221, and the main body 121 includes a connecting layer 1222 and five second blocks 1211.

[0093] In some embodiments, referring to FIG5, the dimension d of the first block 1221 in the width direction of the magnet 12 is smaller than the dimension e of the second block 1211 in the width direction of the magnet 12.

[0094] It should be noted that in this embodiment, the first block 1221 and the second block 1211 are respectively derived from the magnet end 122 and the main body 121 on the same magnet component 12.

[0095] The first segment 1221 is smaller in width direction than the second segment 1211. In other words, the segments at both ends of the magnet 12, where eddy current loss is usually high, are more finely layered. This further reduces the overall eddy current loss of the magnet 12 and decreases the probability of demagnetization due to high temperature.

[0096] In some embodiments, a connecting layer 1222 is provided between the magnet end 122 and the main body 121.

[0097] In other words, the magnet end 122 and the main body 121 are connected as a whole magnet part 12 through the connecting layer 1222. The setting of the connecting layer 1222 can increase the magnetic resistance between the magnet end 122 and the main body 121, thereby reducing the overall eddy current loss of the magnet part 12.

[0098] In some embodiments, the magnet 12 installed in the same magnet slot 11c is divided into multiple segments along the axial direction, and the segments are connected by a connecting layer 1222.

[0099] The multiple segments or more mentioned in the embodiments of this application refer to two or more segments.

[0100] The magnet 12 is cut into multiple segments along the axial direction, which can also reduce the eddy currents in the magnet 12, thereby reducing the temperature rise of the magnet 12 during operation, which is beneficial to the high-speed and stable operation of the rotor 10.

[0101] In some embodiments, the connecting layer 1222 includes an insulating film and an insulating adhesive.

[0102] For example, an insulating film is wrapped around the first segment 1221, and the first segments 1221 covered with the insulating film are bonded together by insulating adhesive.

[0103] For example, the two large surfaces of the insulating film are respectively coated with insulating adhesive, the insulating film serves as the substrate of the insulating adhesive, and the insulating adhesive on the two large surfaces of the insulating film is used to bond the first segment 1221.

[0104] For example, the insulating film is a thin film with high insulating properties.

[0105] Thus, by using insulating film and insulating adhesive to bond each of the first segments 1221 and each of the second segments 1211, or to bond the magnet end 122 to the main body 121, the insulation performance of the connecting layer 1222 can be improved, thereby reducing the eddy currents of the magnet 12.

[0106] In some embodiments, please refer to FIG5, the dimensions of each magnet end 122 in the width direction of the magnet part 12 are smaller than the dimensions of the main body 121 in the width direction of the magnet part 12.

[0107] As shown in Figure 5, the dimension of the magnet end 122 in the width direction of the magnet part 12 is represented by f, and the dimension of the main body 121 in the width direction of the magnet part 12 is represented by g.

[0108] For example, the ratio of the dimension f of the magnet end 122 in the width direction of the magnet part 12 to the dimension g of the main body 121 in the width direction of the magnet part 12 is in the range of 0.16-0.35.

[0109] For example, the ratio of the dimension f of the magnet end 122 in the width direction of the magnet part 12 to the dimension g of the main body 121 in the width direction of the magnet part 12 is 0.16, 0.18, 0.2, 0.22, 0.25, 0.28, 0.3, 0.32 or 0.35, etc.

[0110] In other words, by controlling the dimensions of each magnet end 122 in the width direction of the magnet part 12, and providing thicker magnet ends 122 at both ends of the magnet part 12 in the width direction only corresponding to the larger eddy currents, it is possible to save materials and at the same time reduce the impact of the increased thickness of the magnet ends 122 on the weak magnetic properties.

[0111] In some embodiments, referring to Figures 3 to 5, the magnet groove 11c protrudes along the groove wall in the thickness direction of the magnet 12 to form a protrusion 11d. The protrusion 11d matches the groove 12a to limit the magnet 12 in the width direction.

[0112] For example, the protrusion 11d extends axially and the groove 12a extends along the length of the magnet 12. In this way, the protrusion 11d of the magnet groove 11c can guide the magnet 12 by cooperating with the groove 12a, which is beneficial to the installation of the magnet 12.

[0113] It should be noted that the number of protrusions 11d on the same magnet groove 11c corresponds to the number of grooves 12a on the magnet part 12. It can be a protrusion 11d formed on one side of the groove wall along the thickness direction of the magnet groove 11c, or it can be two protrusions 11d formed on both sides of the groove wall along the thickness direction of the magnet groove 11c.

[0114] It should be noted that a primer can be applied to the inside of the magnet trough 11c before the magnet part 12 is placed in it.

[0115] Primer is an adhesion promoter used before coating. It is mainly used to improve the interfacial polarity or wettability of the substrate surface to enhance the adhesion between the coating and the substrate. In this way, the adhesion between the magnet 12 and the magnet groove 11c can be increased.

[0116] Thus, by forming a protrusion 11d in the magnet groove 11c, and matching the protrusion 11d of the magnet groove 11c with the groove 12a of the magnet part 12, the fixing effect of the magnet groove 11c on the magnet part 12 in the width direction of the magnet part 12 can be improved, thereby improving the overall compactness of the rotor 10, increasing the natural frequency of the rotor 10, and further improving the reliability of the high-speed rotation of the rotor 10.

[0117] In some embodiments, referring to Figure 3, magnetic isolation cavities 11e are respectively provided at both ends of the magnetic steel groove 11c along the width direction of the magnetic steel component 12. The magnetic isolation cavities 11e are connected to the magnetic steel groove 11c. The groove walls of the magnetic steel groove 11c along the width direction of the magnetic steel component 12 respectively limit the magnetic steel component 12 in the width direction of the magnetic steel component 12.

[0118] The magnetic isolation cavity 11e is connected to the magnetic steel groove 11c, which means that part of the magnetic steel groove 11c is connected along the groove wall in the width direction of the magnetic steel component 12, thereby realizing the connection between the magnetic steel groove 11c and the magnetic isolation cavity 11e at both ends of the magnetic steel groove 11c.

[0119] The fact that the groove wall of the magnetic steel groove 11c along the width direction of the magnetic steel part 12 limits the magnetic steel part 12 in the width direction means that the groove wall of the magnetic steel groove 11c that does not penetrate the magnetic isolation cavity 11e along the width direction of the magnetic steel part 12 is used to limit the magnetic steel part 12 in the width direction of the magnetic steel part 12.

[0120] The wall of the magnetic groove 11c used to limit the magnetic steel part 12, that is, the wall of the magnetic groove 11c that does not penetrate the magnetic isolation cavity 11e, can be located at one end along the thickness direction of the magnetic steel part 12, or at the other end along the thickness direction of the magnetic steel part 12, or at both ends along the thickness direction of the magnetic steel part 12. There are no restrictions here.

[0121] In this embodiment, the magnetic isolation cavity 11e is used to fill potting compound, which is an insulating material with a heat resistance rating of 200.

[0122] It should be noted that before filling the magnetic isolation cavity 11e with potting compound, the magnetic isolation cavities 11e located at both ends of the magnet groove 11c facilitate the assembly personnel in placing the magnet component 12 into the magnet groove 11c using the space of the magnetic isolation cavity 11e. Simultaneously, the groove walls on both sides of the magnet groove 11c along the width direction of the magnet component 12 can limit and guide the magnet component 12, which is beneficial for its installation. After the magnetic isolation cavity 11e is filled with potting compound, the potting compound can fix the magnet component 12 at both ends along the width direction of the magnet component 12, thereby improving the fixing strength of the magnet component 12.

[0123] In some embodiments, please refer to Figures 1 and 2. The rotor 10 also includes a shaft 13 and rotor pressure rings 14 made of low-permeability, high-strength, non-magnetic steel. The two rotor pressure rings 14 are respectively interference-fitted with the shaft 13 to apply a certain axial preload between the two ends of the rotor core 11, thereby improving the compactness and reliability of the entire rotor 10.

[0124] For example, after the rotor pressure ring 14 and rotor core 11 of the rotor 10 at the drive end are installed on the rotating shaft 13, during the assembly of the rotor pressure ring 14 at the non-drive end, a clamping force of 130kN is applied to the rotor pressure ring 14 at the non-drive end towards the rotor pressure ring 14 at the drive end, so that there is a certain axial preload between the two rotor pressure rings 14, which is beneficial to the integrated production of the rotor 10 and improves the compactness and reliability of the entire rotor 10.

[0125] In some embodiments, after assembly, the rotor 10 can be vacuum impregnated to impregnate the tiny gaps in the rotor 10 and form a protective varnish film on the surface. For example, the gaps between the laminations on the rotor core 11 formed by stacking rotor laminations.

[0126] In some embodiments, after the rotor 10 is assembled, it can be potted with potting compound to fill the larger pores of the rotor 10.

[0127] It should be noted that the vacuum impregnation and glue pouring processes can be performed in any order; vacuum impregnation can be performed first, followed by glue pouring, or glue pouring can be performed first, followed by vacuum impregnation.

[0128] Vacuum impregnation and potting can increase the adhesion between the rotor core 11 and the magnet 12, resulting in better compactness between the rotor core 11 and the magnet 12. This is beneficial for increasing the natural frequency of the rotor 10 and improving the reliability of the rotor 10.

[0129] For example, the insulating varnish, primer and potting compound in this application are all made of insulating materials with a heat resistance rating of 200, that is, the maximum permissible operating temperature of the insulating varnish, primer and potting compound is 200°C.

[0130] In some embodiments, please refer to Figure 3, the rotor core 11 is also provided with magnetic barrier holes 11f and ventilation holes 11g.

[0131] Among them, the magnetic barrier hole 11f is used to reduce the air gap magnetic flux density waveform and reduce the armature back electromotive force harmonic distortion rate.

[0132] The ventilation hole 11g is used to air cool the rotor core 11 and reduce the temperature of the rotor 10 during operation.

[0133] A second aspect of this application provides an electric motor, including a rotor 10 provided in any embodiment of this application.

[0134] It should be noted that the motor can be a permanent magnet synchronous motor.

[0135] The motor provided in this application embodiment arranges at least two magnet slots 11c of the magnet slot group 11a in a V-shape with the opening facing outwards. The magnet slots 11c are symmetrical along the first axis s of the rotor 10, such that the magnets 12 disposed in the magnet slots 11c have one end 122 close to the first axis s along the width direction, and the other end 122 close to the side wall of the rotor core 11. The thickness of the two ends 122 is greater than the thickness of the middle main body 121. Thus, the magnet ends 122 disposed at both ends of the magnet slots 11c in the width direction are close to the first axis s and the side wall of the rotor core 11, respectively. On the one hand, increasing the thickness of the magnet end 122 near the first axis s can improve the demagnetization resistance of the magnet 12 near the first axis s. On the other hand, the magnet 12 near the side wall of the rotor core 11, that is, near the air gap of the stator and rotor 10, can improve the demagnetization resistance of the magnet 12 near the surface of the rotor 10 by increasing the thickness of the magnet end 122 in this part. Furthermore, the thickness of the main body 121 is thinner than that of the magnet end 122, which can reduce magnetic resistance, increase D-axis inductance, reduce three-phase short-circuit current, and improve the continuous operation capability of the motor under fault conditions such as three-phase short circuit.

[0136] The various embodiments / implementations provided in this application can be combined with each other without creating contradictions.

[0137] The above description is merely a preferred embodiment of this application and is not intended to limit the application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of protection of this application.

Claims

1. A rotor, wherein, The rotor core is provided with a plurality of magnetic steel slot groups in the circumferential direction, each of the magnetic steel slot groups comprises at least two magnetic steel slots arranged in a V shape with the opening facing outward, the two magnetic steel slots are symmetrical along a first axis of the rotor, one end of the magnetic steel slots is close to the first axis, and the other end is close to the side wall of the rotor core. The magnetic steel piece is arranged in the magnetic steel slot, the magnetic steel piece comprises a main body part and magnetic steel end parts arranged at both ends of the main body part in the width direction, the thickness of the magnetic steel end parts is greater than the thickness of the main body part. The width direction of the magnetic steel piece is perpendicular to the axial direction of the rotor. The first axis is the D-axis of the rotor; and / or 2. The rotor of claim 1, wherein, The magnetic steel slot group comprises two magnetic steel slot units, each of the magnetic steel slot units comprises two magnetic steel slots arranged in a V shape with the opening facing outward, and the two magnetic steel slot units are arranged at intervals along the first axis. One of the magnetic steel end parts of the magnetic steel piece is close to the first axis, and the other magnetic steel end part is close to the side wall of the rotor core, the main body part is flush with the side wall on one side of the magnetic steel piece in the thickness direction, and the other side wall forms a groove.

3. The rotor of claim 1, wherein, The magnetic steel end part comprises a connecting layer and at least two first sub-blocks, adjacent two first sub-blocks are connected through the connecting layer, and each first sub-block is arranged in the width direction of the magnetic steel piece; and / or 4. The rotor of claim 3, wherein, The main body part comprises a connecting layer and at least two second sub-blocks, adjacent two second sub-blocks are connected through the connecting layer, and each second sub-block is arranged in the width direction of the magnetic steel piece. The size of the first sub-block in the width direction of the magnetic steel piece is smaller than the size of the second sub-block in the width direction of the magnetic steel piece.

5. The rotor of claim 4, wherein, The connecting layer is arranged between the magnetic steel end part and the main body part; and / or 6. The rotor of claim 4, wherein, The connecting layer comprises an insulating film and an insulating adhesive. The size of each magnetic steel end part in the width direction of the magnetic steel piece is smaller than the size of the main body part in the width direction of the magnetic steel piece.

7. The rotor of claim 3 wherein, The slot wall of the magnetic steel slot in the thickness direction of the magnetic steel piece is protruding to form a protruding part, the protruding part is matched with the groove to limit the magnetic steel piece in the width direction.

8. The rotor of claim 3 wherein, In the width direction of the magnetic steel piece, the two ends of the magnetic steel slot are further respectively provided with a magnetic isolation cavity, the magnetic isolation cavity is communicated with the magnetic steel slot, and the slot wall of the magnetic steel slot in the width direction of the magnetic steel piece limits the magnetic steel piece in the width direction of the magnetic steel piece.

9. The rotor of claim 1, wherein, The rotor comprises any one of the rotors as claimed in claims 1 to 9.

10. An electric machine wherein, ​

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