Rotor structure and motor

Abstract

The invention provides a rotor structure and a motor, the rotor structure comprises a rotor iron core, the rotor iron core is provided with a plurality of assembling groove groups, the plurality of assembling groove groups are arranged at intervals along the circumferential direction of the rotor iron core, each assembling groove group comprises two first magnetic steel grooves, the cross section of the rotor iron core is taken as a projection plane, and the two first magnetic steel grooves are arranged in a V shape. The opening of the V shape faces the peripheral wall of the rotor core, the two first magnetic steel grooves are symmetrically arranged about the d axis, first permanent magnets are arranged in the first magnetic steel grooves, a plurality of first protrusions are arranged on the side walls, facing the d axis, of the first magnetic steel grooves, a plurality of first grooves are formed in the first permanent magnets, and the first protrusions and the first grooves are arranged in a one-to-one correspondence mode; the first bulge is positioned in the first groove; the first groove is located in the middle of the first permanent magnet in the extending direction of the first permanent magnet. According to the invention, the technical problem of large eddy current loss during high-speed operation of the motor in the prior art can be solved.

Description

Technical Field

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

[0002] Modern motors tend to have high power density. The compression of permanent magnet volume results in higher electromagnetic and thermal loads per unit area, which doubles the risk of demagnetization. The performance and reliability of permanent magnet motors are highly dependent on the stability of the magnetic properties of permanent magnets. Demagnetization is one of the core causes of failure. The risk of demagnetization of motors increases greatly under heavy load, high speed, and closed conditions. In addition, the reverse magnetic field generated by the stator armature reaction will weaken the magnetic properties of the permanent magnets, greatly reducing the life of the permanent magnet motor.

[0003] Traditional permanent magnets often use a monolithic structure. This refers to an embedded rotor, where the permanent magnets are completely embedded in the rotor core. When operating at high speeds, the alternating magnetic field induces extensive eddy current loops within the permanent magnets, increasing motor temperature and eddy current losses, severely limiting motor reliability. Traditional designs are also prone to magnetic flux leakage or magnetic circuit saturation, leading to a decrease in power factor and reduced motor efficiency.

[0004] Since the alternating magnetic field of the motor in the prior art induces a large-scale eddy current loop in the permanent magnet when the motor runs at high speed, resulting in increased eddy current loss and other technical problems, the present invention studies and designs a rotor structure and a motor. Summary of the Invention

[0005] Therefore, the present invention provides a rotor structure and a motor, which can solve the technical problem in the prior art that the eddy current loss is large when the motor runs at high speed.

[0006] In order to solve the above problems, the present invention provides a rotor structure, including a rotor core, on which multiple groups of assembly slot groups are provided, and the multiple groups of assembly slot groups are arranged at intervals along the circumference of the rotor core, and the assembly slot groups include two first magnetic steel slots. With the cross-section of the rotor core as the projection plane, the two first magnetic steel slots are arranged in a V-shape, and the opening of the V-shape faces the outer peripheral wall of the rotor core. The two first magnetic steel slots are arranged symmetrically about the d-axis, and a first permanent magnet is provided in the first magnetic steel slot. A plurality of first protrusions are provided on the side wall of the first magnetic steel slot facing the d-axis, and a plurality of first grooves are provided on the first permanent magnet. The first protrusions are arranged in a one-to-one correspondence with the first grooves, and the first protrusions are located in the first grooves; along the extension direction of the first permanent magnet, the first groove is located in the middle of the first permanent magnet.

[0007] In some embodiments, the assembly groove group includes a second groove, and with the cross-section of the rotor core as the projection surface, the second groove is a V-shaped structure, the opening of the V-shaped structure faces the center of the rotor core, and the first magnetic steel groove is connected to the second groove.

[0008] In some embodiments, a side of the second groove close to the center of the rotor core has an angle D, and a side of the second groove away from the center of the rotor core has an angle C, which satisfies 90°≤C≤D≤130.

[0009] In some embodiments, an angle C1 is formed between a side of the second groove away from the center of the rotor core and a side wall of the second magnetic steel slot close to the d-axis, which satisfies 0.7≤C1 / C≤0.9.

[0010] In some embodiments, the side length of the second groove close to the center of the rotor core is L1, and the side length of the second groove away from the center of the rotor core is L2, which satisfies, 0.5 <L1 / L2<1。

[0011] In some embodiments, an angle A is formed between the side walls of the two first magnetic steel slots facing each other, which satisfies 75°≤A≤90°.

[0012] In some embodiments, the assembly slot group also includes two second magnetic steel slots, the second magnetic steel slots are located between the two first magnetic steel slots, the two second magnetic steel slots are symmetrically arranged about the d axis, the two second magnetic steel slots are arranged in a V shape, and the V-shaped openings of the two second magnetic steel slots face the outer peripheral wall of the rotor core, the second magnetic steel slots are arranged close to the outer peripheral wall of the rotor core, the second permanent magnet is in the second magnetic steel slot, a plurality of second protrusions are provided on the inner side wall of the second magnetic steel slot, a plurality of third grooves are provided on the second permanent magnet, the second protrusions are arranged one-to-one with the third grooves, and the second protrusions are located in the third grooves; along the extension direction of the second permanent magnet, any of the third grooves is located in the middle of the first permanent magnet.

[0013] In some embodiments, an angle B is formed between two of the second magnetic steel slots, which satisfies 0.625≤B / A≤0.75.

[0014] In some embodiments, with the cross section of the rotor core as the projection plane, the width of the first permanent magnet is T1, and the width of the first permanent magnet is T2, which satisfies T1=T2; the groove depth of the first groove is D1, which satisfies T1=3D1.

[0015] In some embodiments, the groove depth of the third groove is D3, and the groove width of the third groove is W4, which satisfies 3 / W4≤D3≤2 / W4.

[0016] In some embodiments, the assembly slot group also includes two fourth grooves, the fourth grooves are arranged in a one-to-one correspondence with the second channel steel slots, the fourth grooves are connected with the second magnetic steel slots, the second magnetic steel slots have a second end face close to the outer peripheral wall of the rotor iron core and a first end face away from the outer peripheral wall of the rotor iron core, the fourth grooves are connected with the second end face, the fourth grooves extend along the circumference of the rotor iron core, and the extension direction of the fourth grooves is toward the first magnetic steel slots.

[0017] In some embodiments, with the cross section of the rotor core as a projection surface, the minimum distance between the fourth groove and the outer circle of the rotor core is T3, which satisfies 0.25 mm ≤ T3 ≤ 0.5 mm.

[0018] In some embodiments, the minimum distance between the first magnetic steel groove and the fourth groove is Q1, which satisfies 1.4 mm ≤ Q1 ≤ 1.5 mm.

[0019] In some embodiments, the width of the second permanent magnet is W5, the minimum distance between the third groove and the second end face is L4, the minimum distance between the third groove and the first end face is L5, and the minimum distance between two adjacent third grooves is L6, which satisfies W4 / W5=1 / 2, 1.2 mm. <L5+L6<L4。

[0020] In some embodiments, along the extension direction of the first permanent magnet, the start and end distances of the plurality of first grooves are L3, and the length of the first permanent magnet is W3, which satisfies 0.14≤L3 / W3≤0.16.

[0021] The present invention also provides a motor, which includes the aforementioned rotor structure.

[0022] The rotor structure and motor provided by the present invention have the following beneficial effects:

[0023] As modern motors tend to develop towards high power density, the volume compression of permanent magnets leads to higher electromagnetic and thermal loads per unit area, and the risk of demagnetization is doubled. By providing the first protrusion and the first groove, the eddy current path can be divided, the eddy current loss can be reduced, and the demagnetization effect of the armature magnetic field on the permanent magnet can be dispersed, so that the demagnetization rate of the outer end of the permanent magnet is reduced and the overall anti-demagnetization ability of the permanent magnet is improved. At the same time, the groove structure of the permanent magnet can reduce the eddy current heating of the permanent magnet, reduce the thermal demagnetization effect caused by the excessive heating temperature of the permanent magnet, reduce the eddy current loss of the permanent magnet, and improve the overall efficiency of the motor. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] To more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for the embodiments or the description of the prior art. The drawings described below are merely exemplary. Those skilled in the art can, without inventive effort, derive other implementation drawings based on the provided drawings.

[0025] Figure 1 is an assembly structure diagram of the rotor structure of the present invention;

[0026] Figure 2 This is a schematic diagram of the rotor structure of the present invention. Figure 1 ;

[0027] Figure 3 This is a partial enlargement of the rotor structure of the present invention. Figure 1 ;

[0028] Figure 4 This is a partial enlargement of the rotor structure of the present invention. Figure 2 ;

[0029] Figure 5 This is a schematic diagram of the rotor structure of the present invention. Figure 2 ;

[0030] Figure 6 This is a partial enlargement of the rotor structure of the present invention. Figure 3 ;

[0031] Figure 7 This is a partial enlargement of the rotor structure of the present invention. Figure 4 ;

[0032] Figure 8 This is a partial enlargement of the rotor structure of the present invention. Figure 5 ;

[0033] Figure 9 This is a partial enlargement of the rotor structure of the present invention. Figure 6 ;

[0034] Figure 10 This is a comparison diagram of the demagnetization and ionization of the rotor structure of the present invention and the prior art;

[0035] Figure 11 This is a comparison chart of the motor efficiency between the rotor structure of the present invention and the prior art.

[0036] The accompanying drawings are:

[0037] 1. Rotor core; 2. First magnetic steel slot; 3. First permanent magnet; 4. Second magnetic steel slot; 5. Second permanent magnet; 6. First groove; 7. Second groove; 8. Third groove; 9. Fourth groove; 10. Stator; 11. First end face; 12. Second end face. DETAILED DESCRIPTION

[0038] The following will be combined with the accompanying drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, rather than all the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is in no way intended to limit the present invention and its application or use. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0039] In the description of the present invention, it should be understood that the directions or positional relationships indicated by directional words such as "front, back, up, down, left, right", "horizontal, vertical, perpendicular, horizontal" and "top, bottom" are usually based on the directions or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description. Unless otherwise specified, these directional words do not indicate or imply that the device or element referred to must have a specific direction or be constructed and operated in a specific direction. Therefore, they cannot be understood as limiting the scope of protection of the present invention; the directional words "inside and outside" refer to the inside and outside relative to the outline of each component itself.

[0040] For ease of description, spatially relative terms such as "above", "above", "on the upper surface of", "above", etc. may be used herein to describe the spatial positional relationship of a device or feature to other devices or features as shown in the figures. It should be understood that spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation described in the figures. For example, if the device in the drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below other devices or structures". Thus, the exemplary term "above" can include both "above" and "below". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatially relative descriptions used here are interpreted accordingly.

[0041] In addition, it should be noted that the use of terms such as "first" and "second" to limit components is only for the convenience of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore cannot be understood as limiting the scope of protection of the present invention.

[0042] See also Figure 1-11As shown, according to an embodiment of the present invention, a rotor structure is provided, including: a rotor core 1, on which a plurality of assembly slot groups are provided, and the plurality of assembly slot groups are arranged at intervals along the circumference of the rotor core 1, and the assembly slot groups include two first magnetic steel slots 2. With the cross section of the rotor core 1 as the projection plane, the two first magnetic steel slots 2 are arranged in a V-shape, and the opening of the V-shape faces the outer peripheral wall of the rotor core 1. The two first magnetic steel slots 2 are symmetrically arranged about the d-axis, and a first permanent magnet 3 is provided in the first magnetic steel slot 2. A plurality of first protrusions are provided on the side wall of the first magnetic steel slot 2 facing the d-axis, and a plurality of first grooves 6 are provided on the first permanent magnet 3. The first protrusions are arranged in a one-to-one correspondence with the first grooves 6, and the first protrusions are located in the first grooves 6; along the extension direction of the first permanent magnet 3, the first groove 6 is located in the middle of the first permanent magnet 3.

[0043] In this technical solution, in view of the trend of modern motors to develop high power density, the volume compression of permanent magnets leads to higher electromagnetic loads and thermal loads per unit area, and the risk of demagnetization is doubled. By using the first protrusion and the first groove 6, the eddy current path can be divided, the eddy current loss can be reduced, and the demagnetization effect of the armature magnetic field on the permanent magnet can be dispersed, so that the demagnetization rate of the outer end of the permanent magnet is reduced, and the overall anti-demagnetization ability of the permanent magnet is improved. At the same time, this groove structure of the permanent magnet can reduce the eddy current heating of the permanent magnet, reduce the thermal demagnetization effect caused by the excessive heating temperature of the permanent magnet, reduce the eddy current loss of the permanent magnet, and improve the overall efficiency of the motor.

[0044] In some embodiments, as shown in FIG8 , the openings of the first grooves 6 on the two first permanent magnets 3 face each other, and there are three first grooves 6 and three first protrusions. In a single first groove 6, the first grooves 6 on both sides are symmetrically arranged about the middle first groove 6, and the middle first groove 6 is symmetrically arranged about the middle of the first permanent magnet 3. The groove depth of the first groove 6 is less than the width of the first permanent magnet 3. The groove width and groove depth of the multiple first grooves 6 are the same.

[0045] In some embodiments, with the cross section of the rotor core 1 as the projection plane, the first magnetic steel slot 2 is trapezoidal and the first permanent magnet 3 is rectangular, so that both ends of the first permanent magnet 3 and the first magnetic steel slot 2 have air slots, further reducing magnetic leakage.

[0046] In some embodiments, the assembly groove group includes a second groove 7. Taking the cross-section of the rotor core 1 as the projection surface, the second groove 7 is a V-shaped structure, the opening of the V-shaped structure faces the center of the rotor core 1, and the first magnetic steel slot 2 is connected to the second groove 7.

[0047] In this technical solution, the second groove 7 forms a magnetic isolation structure. Through the second groove 7, a part of the magnetic flux lines can be blocked from bypass leakage in the tip region of the V-shaped magnet, reducing the ineffective magnetic leakage of the permanent magnet, thereby adjusting the magnetic field path, making the magnetic field more concentrated to enter the stator through the air gap, and improving the low-frequency efficiency of the motor.

[0048] In some embodiments, the two first magnet grooves 2 and the second groove 7 form a V-shaped structure with opposite opening directions. Referring to Figure 3 As shown, the second groove 7 has a first side and a second side away from the center of the rotor core 1. The two first magnet grooves 2 are respectively connected to the first side and the second side. The connection point of the first side and the second side is located between the two first magnet grooves 2. The first side and the second side are connected by an arc. Moreover, the width of the first magnet groove 2 is less than the length of the first side, and the lengths of the first side and the second side are equal.

[0049] In some embodiments, one side of the second groove 7 close to the center of the rotor core 1 has an included angle D, and one side of the second groove 7 away from the center of the rotor core 1 has an included angle C, which satisfies 90° ≤ C ≤ D ≤ 130.

[0050] In this technical solution, the second groove 7 has an inverted V-shaped structure. The inverted V-shaped structure is a continuous magnetic isolation structure. The included angle on the side close to the outer circle of the rotor is set as C, and the included angle on the side close to the inner circle of the rotor is set as D, where 90° ≤ C ≤ D ≤ 130. This continuous magnetic isolation structure can block part of the magnetic flux lines from bypass leakage in the V-shaped tip region, reducing ineffective magnetic leakage.

[0051] In some embodiments, there is an included angle C1 between the side of the second groove 7 away from the center of the rotor core 1 and the side wall of the second magnet groove 2 near the d-axis, which satisfies 0.7 ≤ C1 / C ≤ 0.9.

[0052] In this technical solution, by 0.7 ≤ C1 / C ≤ 0.9, the magnetic energy utilization rate of the permanent magnet can be improved, the air-gap magnetic density can be increased, thereby improving the output torque and efficiency of the motor.

[0053] In some embodiments, the side length of the side of the second groove 7 close to the center of the rotor core 1 is L1, and the side length of the side of the second groove 7 away from the center of the rotor core 1 is L2, which satisfies 0.5 < L1 / L2 < 1.

[0054] In this technical solution, preferably, 3 mm < L1 < L2 < 4.5 mm. By 0.5 < L1 / L2 < 1, the centrifugal stress during the high-speed rotation of the rotor can be dispersed, avoiding local stress concentration.

[0055] In some embodiments, there is an included angle A between the side walls of the two first magnet grooves 2 facing each other, which satisfies 75° ≤ A ≤ 90°.

[0056] In this technical solution, by setting 75°≤A≤90°, the magnetic field concentration effect of the V-shaped structure can be fully utilized to increase the air gap magnetic density and thus improve the low-frequency efficiency of the motor.

[0057] In some embodiments, the assembly slot group also includes two second magnetic steel slots 4, which are located between the two first magnetic steel slots 2, and the two second magnetic steel slots 4 are symmetrically arranged about the d axis. The two second magnetic steel slots 4 are arranged in a V shape, and the V-shaped openings of the two second magnetic steel slots 4 face the outer peripheral wall of the rotor core 1. The second magnetic steel slots 4 are arranged close to the outer peripheral wall of the rotor core 1. The second permanent magnet 5 is in the second magnetic steel slot 4, and a plurality of second protrusions are provided on the inner side wall of the second magnetic steel slot 4. A plurality of third grooves 8 are provided on the second permanent magnet 5, and the second protrusions are arranged one-to-one with the third grooves 8, and the second protrusions are located in the third grooves 8; along the extension direction of the second permanent magnet 5, any of the third grooves 8 is located in the middle of the first permanent magnet 3.

[0058] In this technical solution, the second magnetic steel slot 4 and the second permanent magnet 5 are used to increase the anti-demagnetization ability of the first permanent magnet 3, and reduce the demagnetization magnetic field component of the armature magnetic field in the magnetizing direction of the first permanent magnet 3. By opening a third groove 8 on the second permanent magnet 5, the larger eddy current loop inside the permanent magnet can be divided, thereby reducing eddy current loss, reducing temperature rise, and improving the overall anti-demagnetization ability of the permanent magnet.

[0059] In some embodiments, the two second magnetic steel slots 4 are arranged in a V shape, and the two second magnetic steel slots 4 are arranged symmetrically about the d axis, and the opening of the third groove 8 is facing away from the first magnetic steel slot 2. There are two third grooves 8, one third groove 8 is located in the middle of the second permanent magnet 5, and the other third groove 8 is located near the outer peripheral wall of the rotor core 1.

[0060] In some embodiments, an angle B is formed between two of the second magnetic steel slots 4 , which satisfies 0.625≤B / A≤0.75.

[0061] In this technical solution, by setting 0.625≤B / A≤0.75, the anti-demagnetization capability of the first permanent magnet 3 is increased, and the demagnetization magnetic field component of the armature magnetic field in the magnetizing direction of the first permanent magnet 3 is reduced.

[0062] In some embodiments, taking the cross section of the rotor core 1 as the projection plane, the width of the first permanent magnet 3 is T1, and the width of the first permanent magnet 5 is T2, which satisfies T1=T2; the groove depth of the first groove 6 is D1, which satisfies T1=3D1.

[0063] In this technical solution, the width of the first permanent magnet 3 is T1, and the width of the first permanent magnet 5 is T2, which satisfies T1 = T2; the depth of the first groove 6 is D1, which satisfies T1 = 3D1. In some embodiments, when there are three first grooves 6, the groove depth of the middle first groove 6 is D2, the groove width of the middle first groove 6 is W2, the groove width of the first grooves 6 on both sides is W1, and the groove depth of the first grooves 6 on both sides is D1, which satisfies D1 = D2, 2.4mm≤T1≤2.6mm, 0.8mm≤D2≤0.87mm, 0.2mm≤W1≤W2≤0.3mm. This setting can divide a large-area eddy current loop into multiple small loops, weaken the permanent magnet's response to the stator current harmonics, and reduce the additional eddy currents induced by the high-frequency magnetic field; refer to Figure 10 and Figure 11 As shown, the rotor structure of the present invention can effectively improve the rotor demagnetization current and motor efficiency.

[0064] In some embodiments, the groove depth of the third groove 8 is D3, and the groove width of the third groove 8 is W4, which satisfies 3 / W4≤D3≤2 / W4.

[0065] In this technical solution, by setting 3 / W4≤D3≤2 / W4, the demagnetization magnetic field component of the armature magnetic field in the magnetizing direction of the second permanent magnet 5 is reduced, thereby reducing the eddy current loss of the third and fourth permanent magnets.

[0066] In some embodiments, the assembly slot group also includes two fourth grooves 9, the fourth grooves 9 are arranged one-to-one with the second channel steel slots 4, the fourth grooves 9 are connected with the second magnetic steel slots 4, the second magnetic steel slots 4 have a second end face 12 close to the outer peripheral wall of the rotor core 1 and a first end face 11 away from the outer peripheral wall of the rotor core 1, the fourth grooves 9 are connected with the second end face 12, the fourth grooves 9 extend along the circumferential direction of the rotor core 1, and the extension direction of the fourth grooves 9 is toward the first magnetic steel slot 2.

[0067] In this technical solution, the fourth groove 9 serves as a magnetic isolation structure, which can avoid magnetic leakage of the second permanent magnet 5.

[0068] In some embodiments, in conjunction with Figure 3 As shown, the end of the fourth groove 9 connected to the second channel steel groove 4 is flared, and the width of the end of the fourth groove 9 connected to the second channel steel groove 4 is smaller than the width of the second channel steel groove 4. There is a gap between the fourth groove 9 and the first magnetic steel groove 2. Taking the cross section of the rotor core 1 as the projection surface, the side of the fourth groove 9 close to the outer peripheral wall of the rotor core 1 and the side of the first magnetic steel groove 2 close to the outer peripheral wall of the rotor core 1 can be connected to form a circle with a diameter slightly smaller than the diameter of the rotor core 1.

[0069] In some embodiments, taking the cross-section of the rotor core 1 as the projection plane, the minimum distance between the fourth groove 9 and the outer circle of the rotor core 1 is T3, which satisfies 0.25 mm ≤ T3 ≤ 0.5 mm.

[0070] In this technical solution, referring to Figure 6 as described, among two adjacent sets of assembly grooves, the minimum distances between the fourth groove 9 and the outer circle of the rotor core 1 include T3, T4, and T5, where T3 = T4 = T5. There is a corner fourth groove 9 on the side of the second magnet groove 4 near the outer circle of the rotor. The direction of the corner fourth groove 9 points to the rotor q-axis. The distance between the side of the fourth groove 9 near the outer circle and the outer circle of the rotor is set as T3. The thickness of the corner of the magnet groove is T4, and the thickness of the magnet groove where the first and second permanent magnets are located near the outer circle of the rotor is set as T5. Among them, 0.25 mm ≤ T3 = T4 = T5 ≤ 0.5 mm. This design of the fourth groove 9 can reduce the lateral magnetic leakage between permanent magnets and improve the effective air-gap magnetic flux density.

[0071] In some embodiments, the minimum distance between the first magnet groove 2 and the fourth groove 9 is Q1, which satisfies 1.4 mm ≤ Q1 ≤ 1.5 mm.

[0072] In this technical solution, by 1.4 mm ≤ Q1 ≤ 1.5 mm, the structural strength of this area is ensured, and deformation caused by the influence of centrifugal force during high-speed rotation is avoided. The angle between the side length of the first end face 11 of the corner of the second magnet groove 4 and the second permanent magnet 5 is set as P, where 25° ≤ P ≤ 35°, guiding the magnetic force line path and reducing the inter-pole magnetic leakage of the permanent magnet.

[0073] In some embodiments, the width of the second permanent magnet 5 is W5, the minimum distance between the third groove 8 and the second end face 12 is L4, the minimum distance between the third groove 8 and the first end face 11 is L5, and the minimum distance between two adjacent third grooves 8 is L6, which satisfies W4 / W5 = 1 / 2, 1.2 mm < L5 + L6 < L4.

[0074] In this technical solution, by W4 / W5 = 1 / 2, 1.2 mm < L5 + L6 < L4, the demagnetizing magnetic field component of the armature magnetic field in the magnetization direction of the second permanent magnet 5 is reduced, and the eddy current loss of the second permanent magnet 5 is reduced.

[0075] In some embodiments, along the extension direction of the first permanent magnet 3, the start-stop distance of multiple first grooves 6 is L3, and the length of the first permanent magnet 3 is W3, which satisfies 0.14 ≤ L3 / W3 ≤ 0.16.

[0076] In this technical solution, preferably, 20 mm ≤ W3 ≤ 24 mm, and 0.14 ≤ L3 / W3 ≤ 0.16, thereby reducing the difficulty of the permanent magnet slotting process.

[0077] The present invention also provides a motor comprising the above-mentioned rotor structure.

[0078] The motor of the present invention further comprises a stator 10, Figure 1 As shown, in two adjacent groups of assembly slots, the fourth groove 9 in one group of assembly slots and the gap between two adjacent stator teeth are arranged relative to each other. The two first permanent magnets 3 are symmetrical about the magnetic pole symmetry line, improving the demagnetization consistency of the first permanent magnets 3. The two second permanent magnets 5 are symmetrical about the magnetic pole symmetry line, improving the demagnetization consistency of the second permanent magnets 5 and improving the motor's anti-demagnetization capability. The two first magnetic steel slots 2 are symmetrical about the d-axis, and the two second magnetic steel slots 4 are symmetrical about the d-axis, improving the symmetry of the permanent magnet motor rotor and effectively reducing the motor's noise level.

[0079] In the motor of the present invention, the magnetization direction relative to the direction of the magnetic pole centerline is the same as the magnetization direction of the first permanent magnet 3 and the second permanent magnet 5 on the same side of the d-axis. This design further increases the magnetic flux of each magnetic pole, improves the motor flux linkage, and further improves the output torque and power of the motor, which is beneficial to increasing the motor reluctance torque and weak magnetic expansion range.

[0080] In the motor of the present invention, the corners of the magnetic steel slots are chamfered, and the chamfer radius is R1, where 0.2mm≤R≤2mm, to reduce the magnetic concentration effect at the corners of the magnetic steel slots, reduce the harmonic content of the air gap magnetic density, and reduce the process difficulty during the magnetic steel assembly process;

[0081] The motor of the present invention can reduce internal eddy current losses, increase the heat dissipation surface area of ​​the magnets, avoid demagnetization caused by overheating, and improve motor efficiency. The corners of the magnetic slots near the outer circumference of the rotor, where the third and fourth permanent magnets are located, are oriented toward the rotor's q-axis, reducing magnetic flux leakage at the edges between the poles and improving effective magnetic flux utilization. This solves the problems of poor demagnetization resistance in permanent magnet motors, thermal demagnetization caused by eddy current losses in permanent magnets, easy demagnetization of permanent magnets near the air gap end of permanent magnet motors, easy demagnetization of magnet ends near the inner circumference of the stator, and low efficiency of permanent magnet motors.

[0082] It is easy for those skilled in the art to understand that, under the premise of no conflict, the advantageous technical features of the above-mentioned methods can be freely combined and superimposed.

[0083] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention. The above description is merely a preferred embodiment of the present invention. It should be noted that those skilled in the art can make various improvements and variations without departing from the technical principles of the present invention, and such improvements and variations shall also be considered within the scope of protection of the present invention.

Claims

1. A rotor structure, characterized in that: include: A rotor core (1) is provided with a plurality of assembly slot groups, the plurality of assembly slot groups being arranged at intervals along the circumference of the rotor core (1), the assembly slot groups comprising two first magnetic steel slots (2), the two first magnetic steel slots (2) being arranged in a V-shape with the cross section of the rotor core (1) as a projection surface, the opening of the V-shape facing the outer peripheral wall of the rotor core (1), the two first magnetic steel slots (2) being arranged symmetrically about the d-axis, a first permanent magnet (3) being arranged in the first magnetic steel slot (2), a plurality of first protrusions being provided on the side wall of the first magnetic steel slot (2) facing the d-axis, a plurality of first grooves (6) being provided on the first permanent magnet (3), the first protrusions being arranged in a one-to-one correspondence with the first grooves (6), the first protrusions being located in the first grooves (6); and the first grooves (6) being located in the middle of the first permanent magnet (3) along the extension direction of the first permanent magnet (3).

2. The rotor structure according to claim 1, characterized in that: The assembly groove group includes a second groove (7), with the cross section of the rotor core (1) as a projection surface, the second groove (7) presents a V-shaped structure, the opening of the V-shaped structure faces the center of the rotor core (1), and the first magnetic steel groove (2) is connected to the second groove (7).

3. The rotor structure according to claim 2, characterized in that: The side of the second groove (7) close to the center of the rotor core (1) has an angle D, and the side of the second groove (7) away from the center of the rotor core (1) has an angle C, which satisfies 90°≤C≤D≤130.

4. The rotor structure according to claim 3, characterized in that: An included angle C1 is formed between a side of the second groove (7) away from the center of the rotor core (1) and a side wall of the second magnetic steel slot (2) close to the d-axis, which satisfies 0.7≤C1 / C≤0.

9.

5. The rotor structure according to claim 2, characterized in that: The side length of the second groove (7) close to the center of the rotor core (1) is L1, and the side length of the second groove (7) away from the center of the rotor core (1) is L2, which satisfies, 0.5 <L1 / L2<1。 6. The rotor structure according to claim 1, characterized in that: An angle A is formed between the side walls of the two first magnetic steel slots (2) facing each other, which satisfies the condition of 75°≤A≤90°.

7. The rotor structure according to claim 6, characterized in that: The assembly slot group further includes two second magnetic steel slots (4), the second magnetic steel slots (4) are located between the two first magnetic steel slots (2), the two second magnetic steel slots (4) are symmetrically arranged about the d axis, the two second magnetic steel slots (4) are arranged in a V shape, and the V-shaped openings of the two second magnetic steel slots (4) face the outer peripheral wall of the rotor core (1), the second magnetic steel slots (4) are arranged close to the outer peripheral wall of the rotor core (1), a second permanent magnet (5) is located in the second magnetic steel slot (4), a plurality of second protrusions are provided on the inner side wall of the second magnetic steel slot (4), a plurality of third grooves (8) are provided on the second permanent magnet (5), the second protrusions are arranged in a one-to-one correspondence with the third grooves (8), and the second protrusions are located in the third grooves (8); along the extension direction of the second permanent magnet (5), any of the third grooves (8) is located in the middle of the first permanent magnet (3).

8. The rotor structure according to claim 7, characterized in that: There is an included angle B between the two second magnetic steel slots (4), which satisfies 0.625≤B / A≤0.

75.

9. The rotor structure according to claim 7, characterized in that: Taking the cross section of the rotor core (1) as the projection plane, the width of the first permanent magnet (3) is T1, and the width of the first permanent magnet (5) is T2, which satisfies T1=T2; the groove depth of the first groove (6) is D1, which satisfies T1=3D1.

10. The rotor structure according to claim 7, characterized in that: The groove depth of the third groove (8) is D3, and the groove width of the third groove (8) is W4, which satisfies the following: 3 / W4≤D3≤2 / W4.

11. The rotor structure according to claim 7, characterized in that: The assembly slot group further includes two fourth slots (9), the fourth slots (9) being arranged in one-to-one correspondence with the second slot steel slots (4), the fourth slots (9) being communicated with the second magnetic steel slots (4), the second magnetic steel slots (4) having a second end face (12) close to the outer peripheral wall of the rotor core (1) and a first end face (11) away from the outer peripheral wall of the rotor core (1), the fourth slots (9) being communicated with the second end face (12), the fourth slots (9) extending along the circumferential direction of the rotor core (1), and the extension direction of the fourth slots (9) being toward the first magnetic steel slots (2).

12. The rotor structure according to claim 11, characterized in that: Taking the cross section of the rotor core (1) as the projection surface, the minimum distance between the fourth groove (9) and the outer circle of the rotor core (1) is T3, which satisfies 0.25mm≤T3≤0.5mm.

13. The rotor structure according to claim 11, characterized in that: The minimum distance between the first magnetic steel groove (2) and the fourth groove (9) is Q1, which satisfies 1.4 mm ≤ Q1 ≤ 1.5 mm.

14. The rotor structure according to claim 11, characterized in that: The width of the second permanent magnet (5) is W5, the minimum distance between the third groove (8) and the second end face (12) is L4, the minimum distance between the third groove (8) and the first end face (11) is L5, and the minimum distance between two adjacent third grooves (8) is L6, which satisfies W4 / W5=1 / 2, 1.2 mm <L5+L6<L4。 15. The rotor structure according to claim 1, characterized in that: Along the extension direction of the first permanent magnet (3), the starting and ending distances of the plurality of first grooves (6) are L3, and the length of the first permanent magnet (3) is W3, which satisfies the following: 0.14≤L3 / W3≤0.

16.

16. A motor, characterized in that: The rotor structure comprises the rotor structure according to any one of claims 1 to 15.

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