Motor rotor, motor and vehicle

Abstract

The application provides a motor rotor, a motor and a vehicle. The rotor body comprises a rotor core and a permanent magnet. A plurality of first permanent magnet slot groups and a plurality of second permanent magnet slot groups are formed on the rotor core. The first permanent magnet slot groups and the second permanent magnet slot groups are arranged in a staggered manner along the circumference of the rotor core. The first permanent magnet slot group comprises first permanent magnet slots and second permanent magnet slots which are symmetric about a d-axis and arranged in a V shape. The second permanent magnet slot group comprises third permanent magnet slots and fourth permanent magnet slots which are symmetric about the d-axis and arranged in a V shape. The outer end of the first permanent magnet slot is communicated with the outer end of the fourth permanent magnet slot to form a first belt-shaped magnetic isolation slot. The outer end of the second permanent magnet slot is communicated with the outer end of the third permanent magnet slot to form a second belt-shaped magnetic isolation slot. Two first notches and / or two second notches are formed on the outer circle of the rotor core. The belt-shaped magnetic isolation slot and the notch can effectively optimize the air gap harmonic magnetic field, reduce the air gap harmonic distortion rate, effectively suppress the iron loss at high speed, and improve the motor efficiency.

Description

Motor rotor, motor and vehicle Technical Field

[0001] This invention relates to the field of motor technology, specifically to structural improvements of motor rotors and corresponding motors and vehicles. Background Technology

[0002] With the promotion of new energy vehicles, electric vehicles are becoming increasingly popular, and the market demands higher and higher driving ranges. Currently, the driving range of new energy vehicles in urban driving conditions has reached a relatively high level, but the driving range on highways remains low, typically only 60-70% of that in urban conditions. Analysis of the reasons reveals that, besides the increased wind resistance at high speeds leading to increased energy consumption, the low efficiency of the main drive motor at high speeds is also a major factor. As one of the core components of electric vehicles, how to maximize the high-efficiency range of the main drive motor within the high-speed range (improving the motor efficiency at high speeds) is a pressing issue that needs to be addressed.

[0003] The iron loss of an electric motor mainly consists of hysteresis loss and eddy current loss, both of which are energy losses caused by the alternating magnetic field inside the iron core. The formula for calculating hysteresis loss is:

[0004] Where, k h It is a constant related to material properties, f is the alternation frequency of the magnetic field, and B m is the maximum magnetic flux density, and n is an empirical constant.

[0005] The formula for calculating eddy current loss is:

[0006] Where, k e is the eddy current loss coefficient, which is related to factors such as the resistivity and geometry of the material; f is the alternating frequency of the magnetic field; B m is the maximum magnetic flux density, and V is the volume of the conductor.

[0007] As can be seen from the above formula, the higher the proportion of harmonic magnetic fields (especially higher harmonics) in the air gap, the greater the alternation frequency f of the magnetic field, and therefore the greater the iron loss generated by the iron core; when local magnetic flux density saturation (local magnetic flux density is too high) occurs in the iron core, the maximum magnetic induction intensity B... m The larger the core, the greater the iron loss generated by the core.

[0008] When a permanent magnet synchronous motor operates at high speed, a reverse field weakening current is usually applied in the d-axis direction of the motor to reduce the back EMF of the load. As a result, the armature reaction of the motor is more intense than that under non-field weakening conditions, and the harmonics of the air gap magnetic field increase significantly. The harmonic magnetic field will cause the iron loss of the motor to rise sharply, resulting in severe motor heating and low motor efficiency. Summary of the Invention

[0009] This invention provides a motor rotor, a motor, and a vehicle to solve the problem of low motor efficiency of permanent magnet synchronous motors under high-speed conditions in the prior art.

[0010] To achieve the above-mentioned technical effects, the technical solution adopted by the motor rotor proposed in this invention is as follows:

[0011] An electric motor rotor includes a rotor body, the rotor body comprising:

[0012] A rotor core has multiple first permanent magnet slot groups and multiple second permanent magnet slot groups formed on it. The first and second permanent magnet slot groups are staggered along the circumference of the rotor core. Each first permanent magnet slot group includes a first permanent magnet slot and a second permanent magnet slot arranged in a V-shape, symmetrical about the d-axis. Each second permanent magnet slot group includes a third permanent magnet slot and a fourth permanent magnet slot arranged in a V-shape, symmetrical about the d-axis. The first and fourth permanent magnet slots are adjacent to each other, and the second and third permanent magnet slots are adjacent to each other. The outer end of the body slot is connected to the outer end of the fourth permanent magnet slot to form a first strip-shaped magnetic isolation slot, and the outer end of the second permanent magnet slot is connected to the outer end of the third permanent magnet slot to form a second strip-shaped magnetic isolation slot. The first strip-shaped magnetic isolation slot and the second strip-shaped magnetic isolation slot pass through the q-axis direction and are located in the outer circle region of the rotor core. Two first notches symmetrical about the d-axis are formed on the outer circle of the rotor core between the first permanent magnet slot and the second permanent magnet slot, and / or two second notches symmetrical about the d-axis are formed on the outer circle of the rotor core between the third permanent magnet slot and the fourth permanent magnet slot.

[0013] The permanent magnets are respectively installed in the first permanent magnet slot, the second permanent magnet slot, the third permanent magnet slot and the fourth permanent magnet slot.

[0014] The first permanent magnet slot group and the second permanent magnet slot group are asymmetrical, and the first notch and the second notch are asymmetrical.

[0015] Each of the first permanent magnet slot groups has one first permanent magnet slot and one second permanent magnet slot.

[0016] Each of the second permanent magnet slot groups has one third permanent magnet slot and one fourth permanent magnet slot.

[0017] The first permanent magnet slot includes a first inner permanent magnet slot and a first outer permanent magnet slot located outside the first inner permanent magnet slot. The second permanent magnet slot includes a second inner permanent magnet slot and a second outer permanent magnet slot located outside the second inner permanent magnet slot. The first inner permanent magnet slot and the second inner permanent magnet slot are symmetric about the d-axis and arranged in a V shape. The first outer permanent magnet slot and the second outer permanent magnet slot are symmetric about the d-axis and arranged in a V shape.

[0018] The third permanent magnet slot includes a third inner permanent magnet slot and a third outer permanent magnet slot located outside the third inner permanent magnet slot. The fourth permanent magnet slot includes a fourth inner permanent magnet slot and a fourth outer permanent magnet slot located outside the fourth inner permanent magnet slot. The third inner permanent magnet slot and the fourth inner permanent magnet slot are symmetric about the d-axis and arranged in a V shape. The third outer permanent magnet slot and the fourth outer permanent magnet slot are symmetric about the d-axis and arranged in a V shape.

[0019] The outer end of the first inner permanent magnet slot is connected to the outer end of the fourth inner permanent magnet slot to form the first strip-shaped magnetic isolation slot. The outer end of the second inner permanent magnet slot is connected to the outer end of the third inner permanent magnet slot to form the second strip-shaped magnetic isolation slot.

[0020] Among the two first gaps, one is located on the outer circumference of the rotor core between the first inner permanent magnet slot and the first outer permanent magnet slot, and the other is located on the outer circumference of the rotor core between the second inner permanent magnet slot and the second outer permanent magnet slot.

[0021] Among the two second gaps, one is located on the outer circumference of the rotor core between the third inner permanent magnet slot and the third outer permanent magnet slot, and the other is located on the outer circumference of the rotor core between the fourth inner permanent magnet slot and the fourth outer permanent magnet slot.

[0022] The inner and outer diameters of the first strip-shaped magnetic isolation slot satisfy: 0 < R1 - R2 < 2.4 * gap. The inner and outer diameters of the second strip-shaped magnetic isolation slot satisfy: 0 < R3 - R4 < 2.4 * gap.

[0023] Where, R1 is the outer diameter of the first strip-shaped magnetic isolation slot, R2 is the inner diameter of the first strip-shaped magnetic isolation slot, R3 is the outer diameter of the second strip-shaped magnetic isolation slot, R4 is the inner diameter of the second strip-shaped magnetic isolation slot, and gap is the air gap of the motor, 0 < gap < 2.

[0024] The length A2 of the permanent magnet in the first inner-layer permanent magnet slot satisfies: 0.65*(π / P - 2*D1 / R0)*R0 < A2 < 0.85*(π / P - 2*D1 / R0)*R0, where D1 is the distance from the outer end of the first inner-layer permanent magnet slot to the q-axis, P is the number of pole pairs of the motor, and R0 is the outer diameter of the rotor; the width B2 of the permanent magnet in the fourth inner-layer permanent magnet slot satisfies: 0.5*D1 < B2 < 1.5*D1; the angle V2 between the first inner-layer permanent magnet slot and the second inner-layer permanent magnet slot satisfies: 180° / P < V2 < 360° / P + 20°; the angle V4 between the third inner-layer permanent magnet slot and the fourth inner-layer permanent magnet slot satisfies: 0 < V4 - V2 < 30°; the angle V1 between the first outer-layer permanent magnet slot and the second outer-layer permanent magnet slot satisfies: 145° < V1 < 180°; the angle V3 between the third outer-layer permanent magnet slot and the fourth outer-layer permanent magnet slot satisfies: 0 < V4 - V3 < 30°; D2 is the distance from the outer end of the fourth inner-layer permanent magnet slot to the q-axis, and D1 and D2 satisfy: 2.3 < D1 / D2 < 6.3, and 0 < D2 < 2*gap, where gap is the air gap of the motor; D3 is the distance from the outer end of the first outer-layer permanent magnet slot to the q-axis, D4 is the distance from the outer end of the fourth outer-layer permanent magnet slot to the q-axis, and D3 and D4 satisfy: 2 < D3 / D1 < 5, 0 < D3 - D4 < 0.5*A1, where A1 is the length of the permanent magnet in the first outer-layer permanent magnet slot.

[0025] The first notch is located between the d-axis and the q-axis, and along the circumferential direction from the d-axis towards the q-axis, the depth of the first notch gradually increases.

[0026] The second notch is located between the d-axis and the q-axis, and along the circumferential direction from the d-axis towards the q-axis, the depth of the second notch gradually increases.

[0027] The width G1 and depth F1 of the first notch satisfy: 1 < F1 / Gi < 0.5*B1 / gap + 0.4; the width G2 and depth F2 of the second notch satisfy: 1 < F2 / G2 < 0.85*B1 / gap + 0.4; where, gap < G1 < 1.8*gap, 0 < G1 - G2 < 0.5*Gap + 0.2, B1 is the width of the permanent magnet in the fourth outer-layer permanent magnet slot, and gap is the air gap of the motor.

[0028] The present invention also provides a motor, including the above-mentioned motor rotor.

[0029] The present invention also provides a vehicle, including the above-mentioned motor.

[0030] Compared with the prior art, the present invention has the following advantages and positive effects:

[0031] 1. In the present invention, the outer end of the first permanent magnet slot in the rotor of the motor is connected to the outer end of the adjacent fourth permanent magnet slot to form a first strip-shaped magnetic isolation slot, and the outer end of the second permanent magnet slot is connected to the outer end of the third permanent magnet slot to form a second strip-shaped magnetic isolation slot. This forms multiple first strip-shaped magnetic isolation slots and multiple second strip-shaped magnetic isolation slots arranged circumferentially inside the air gap between the rotor and the stator. Correspondingly, a strip-shaped magnetic isolation bridge is formed on the rotor core outside the first strip-shaped magnetic isolation slots and the second strip-shaped magnetic isolation slots. The multiple first strip-shaped magnetic isolation slots and multiple second strip-shaped magnetic isolation slots arranged circumferentially can play a similar role to the air gap. When the magnetic lines of the main magnetic flux pass through the q-axis, the strip-shaped magnetic isolation slots and the strip-shaped magnetic isolation bridge can effectively slow down the sudden change in magnetic resistance of the magnetic lines of force from the core to the air gap, thereby effectively reducing the risk of magnetic line distortion, reducing the harmonic distortion rate of the air gap magnetic field, thereby reducing the alternation frequency f of the magnetic field, and thus reducing iron loss and improving motor efficiency.

[0032] 2. Since the q-axis is the main path for the main magnetic flux, and since magnetic leakage is prone to occur near the strip-shaped magnetic isolation bridge in the permanent magnet slot, local magnetic flux saturation is likely to occur in the q-axis region at the outer circumference of the rotor. The strip-shaped magnetic isolation bridge can effectively improve the uniformity of the magnetic field distribution, avoid excessively high local magnetic flux density, and thus reduce the maximum magnetic flux density B. m This reduces iron loss.

[0033] 3. Magnetic bridges can effectively block the flow path of eddy currents in local areas, thereby reducing eddy current losses and iron losses;

[0034] 4. In the rotor of the present invention, two first notches symmetrical about the d-axis are formed on the outer circle of the rotor core between the first permanent magnet slot and the second permanent magnet slot, and / or two second notches symmetrical about the d-axis are formed on the outer circle of the rotor core between the third permanent magnet slot and the fourth permanent magnet slot. This can effectively optimize the magnetic reluctance of the magnetic bridge of the permanent magnet slot, make the air gap magnetic field distribution more sinusoidal, thereby reducing the harmonic content of the air gap magnetic field, thereby reducing the alternation frequency f of the magnetic field, and thus reducing iron loss.

[0035] 5. The first and second gaps can also effectively block the flow path of eddy currents in local areas, thereby reducing eddy current losses and iron losses. By modifying the shape of the first and second gaps, the air gap harmonic magnetic field can be effectively optimized, the harmonic distortion rate of the air gap magnetic field can be reduced, thereby effectively suppressing the generation of iron losses at high speeds and improving motor efficiency. Attached Figure Description

[0036] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0037] Figure 1 is a schematic diagram of the motor rotor structure according to some embodiments of the present invention;

[0038] Figure 2 is a partial structural schematic diagram of a motor rotor according to some embodiments of the present invention;

[0039] Figure 3 is a partial structural schematic diagram of the rotor core according to some embodiments of the present invention;

[0040] Figure 4 is a partial structural schematic diagram of the motor rotor according to some embodiments of the present invention;

[0041] Figure 5 is a partial structural schematic diagram of the motor rotor according to some embodiments of the present invention.

[0042] 100. Rotor body; 110. Rotor core; I. First permanent magnet slot group; 111. First permanent magnet slot; 111a. First inner permanent magnet slot; 111b. First outer permanent magnet slot; 112. Second permanent magnet slot; 112a. Second inner permanent magnet slot; 112b. Second outer permanent magnet slot; II. Second permanent magnet slot group; 113. Third permanent magnet slot; 113a. Third inner permanent magnet slot; 113b. Third outer permanent magnet slot; 114. Fourth permanent magnet slot; 114a. Fourth inner permanent magnet slot; 114b. Fourth outer permanent magnet slot; 115. First notch; 116. Second notch; 117. First strip-shaped magnetic isolation slot; 118. Second strip-shaped magnetic isolation slot; 119. Magnetic isolation bridge; III. Outer circle of rotor core; 120. Permanent magnet. Detailed Implementation

[0043] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" 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 direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0044] Furthermore, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0045] The motor in this embodiment of the invention includes a motor stator and a motor rotor arranged coaxially. An air gap is formed between the outer peripheral wall of the motor rotor and the inner peripheral wall of the motor stator, referred to as the air gap.

[0046] Referring to Figures 1 to 3, in some embodiments of the present invention, the motor rotor includes a rotor body 100.

[0047] The rotor body 100 includes a rotor core 110 and a permanent magnet 120.

[0048] Multiple first permanent magnet slot groups I and multiple second permanent magnet slot groups II are formed on the rotor core 110. The first permanent magnet slot groups I and the second permanent magnet slot groups II are staggered along the circumference of the rotor core 110, that is, they are arranged in sequence along the circumference as one first permanent magnet slot group I, one second permanent magnet slot group II, one first permanent magnet slot group I, one second permanent magnet slot group II, ..., and so on. The first permanent magnet slot groups I at each location have the same structure and the same size parameters, and the second permanent magnet slot groups II at each location have the same structure and the same size parameters.

[0049] The first permanent magnet slot group I includes a first permanent magnet slot 111 and a second permanent magnet slot 112 arranged in a V-shape with respect to the d-axis of the motor. That is, the first permanent magnet slot 111 and the second permanent magnet slot 112 have the same structure and dimensions, and their cross-sections are both inclined straight strips, forming a V-shaped structure with the opening facing the outer peripheral wall of the rotor core 110. Similarly, the second permanent magnet slot group II includes a third permanent magnet slot 113 and a fourth permanent magnet slot 114 arranged in a V-shape with respect to the d-axis of the motor. That is, the third permanent magnet slot 113 and the fourth permanent magnet slot 114 have the same structure and dimensions, and their cross-sections are both inclined straight strips, forming a V-shaped structure with the opening facing the outer peripheral wall of the rotor core 110.

[0050] For any given first permanent magnet slot group I and two adjacent second permanent magnet slot groups II, the first permanent magnet slot 111 of the first permanent magnet slot group I is adjacent to the fourth permanent magnet slot 114 of one of the second permanent magnet slot groups II, and the outer end of the first permanent magnet slot 111 is connected to the outer end of the fourth permanent magnet slot 114 to form a first strip-shaped magnetic isolation slot 117; the second permanent magnet slot 112 of the first permanent magnet slot group I is adjacent to the third permanent magnet slot 113 of the other second permanent magnet slot group II, and the outer end of the second permanent magnet slot 112 is connected to the outer end of the third permanent magnet slot 113 to form a second strip-shaped magnetic isolation slot 118. Correspondingly, the rotor core 110 A strip-shaped magnetic bridge 119 is formed on the outside of the first strip-shaped magnetic isolation groove 117 and the second strip-shaped magnetic isolation groove 118; the first strip-shaped magnetic isolation groove 117 and the second strip-shaped magnetic isolation groove 118 pass through the q-axis direction of the motor (i.e., the first strip-shaped magnetic isolation groove 117 and the second strip-shaped magnetic isolation groove 118 pass through their respective q-axis) and are located in the outer circle region of the rotor core, i.e., close to the outer circle III of the rotor core; two first notches 115 symmetrical about the d-axis are formed on the outer circle region of the rotor core between the first permanent magnet groove 111 and the second permanent magnet groove 112, and two second notches 116 symmetrical about the d-axis are formed on the outer circle region of the rotor core between the third permanent magnet groove 113 and the fourth permanent magnet groove 114.

[0051] The permanent magnet 120 is correspondingly arranged in a one-to-one manner with the first permanent magnet slot 111, the second permanent magnet slot 112, the third permanent magnet slot 113, and the fourth permanent magnet slot 114, and is fixedly installed in the first permanent magnet slot 111, the second permanent magnet slot 112, the third permanent magnet slot 113, and the fourth permanent magnet slot 114, respectively. The permanent magnet 120 can be a non-rare earth magnet or a rare earth magnet, and the types of permanent magnets 120 in each permanent magnet slot can be the same or different, without specific restrictions.

[0052] The adjacent first permanent magnet slot group I and its internal permanent magnet 120, and the second permanent magnet slot group II and its internal permanent magnet 120 constitute two adjacent poles of the motor, namely the N pole and the S pole. Multiple first permanent magnet slot groups I and their internal permanent magnets 120, and multiple second permanent magnet slot groups II and their internal permanent magnets 120 constitute multiple pairs of poles of the motor.

[0053] Since the q-axis is the main path for the main magnetic flux, and since magnetic leakage is very likely to occur near the outer end of the permanent magnet 120 slot, local magnetic flux saturation is likely to occur in the region of the rotor outer circle passing through the q-axis. The strip-shaped magnetic isolation slot can play a similar role to the air gap, effectively reducing the fluctuation amplitude of the magnetic reluctance change of the magnetic lines of force from the rotor core 110 to the air gap and from the stator core to the air gap, reducing the harmonic distortion rate of the air gap magnetic field, improving the uniformity of the magnetic field distribution, avoiding excessively high local magnetic flux density, effectively blocking the flow path of eddy currents, thereby reducing the maximum magnetic induction intensity, effectively suppressing the generation of iron loss at high speed, and thus improving the efficiency of the motor.

[0054] Two first notches 115, symmetrical about the d-axis, are formed on the outer circumference of the rotor core between the first permanent magnet slot 111 and the second permanent magnet slot 112. Two second notches 116, symmetrical about the d-axis, are formed on the outer circumference of the rotor core between the third permanent magnet slot 113 and the fourth permanent magnet slot 114. By modifying the shape of the first notches 115 and the second notches 116, the air gap harmonic magnetic field can be effectively optimized, the harmonic distortion rate of the air gap magnetic field can be reduced, thereby effectively suppressing the generation of iron loss at high speed and improving the efficiency of the motor.

[0055] In addition, both the strip-shaped magnetic shielding groove and the notch can effectively block the flow path of eddy currents in local areas, thereby reducing eddy current losses and iron losses. Under the above combination method, the iron losses of the motor at high speeds can be effectively reduced, and the motor efficiency can be significantly improved.

[0056] In some embodiments of the present invention, the first permanent magnet slot group I and the second permanent magnet slot group II are asymmetrical, forming an adjacent pole asymmetrical magnetic circuit design. Since permanent magnet motors are usually controlled by a sine wave, the rotor magnetic circuit should be designed as a sine wave as much as possible to better match the control. The adjacent pole asymmetrical magnetic circuit design can make the entire circumferential air gap magnetic field more sinusoidal. In addition to reducing torque pulsation, the sinusoidal magnetic field distribution can reduce higher harmonics in the magnetic field, reduce the harmonic distortion rate of the air gap magnetic field, thereby reducing the alternation frequency of the magnetic field, and further reducing iron loss, which is conducive to improving motor efficiency.

[0057] Accordingly, the first notch 115 and the second notch 116 are asymmetrical and have different dimensional parameters to match the corresponding magnetic circuit.

[0058] The permanent magnets 120 contained in each permanent magnet slot can be of the same or different types. In order to reduce the cost of the motor, all permanent magnets 120 are of the same type. The permanent magnets 120 in the first inner permanent magnet slot 111a, the second inner permanent magnet slot 112a, the third inner permanent magnet slot 113a, and the fourth inner permanent magnet slot 114a have the same size parameters. The permanent magnets 120 in the first outer permanent magnet slot 111b, the second outer permanent magnet slot 112b, the third outer permanent magnet slot 113b, and the fourth outer permanent magnet slot 114b have the same size parameters.

[0059] In some embodiments of the present invention, as shown in Figures 1 to 3, the first permanent magnet slot 111 includes a first inner permanent magnet slot 111a and a first outer permanent magnet slot 111b located outside the first inner permanent magnet slot 111a; the second permanent magnet slot 112 includes a second inner permanent magnet slot 112a and a second outer permanent magnet slot 112b located outside the second inner permanent magnet slot 112a. The first inner permanent magnet slot 111a and the second inner permanent magnet slot 112a are symmetrical about the d-axis and arranged in a V-shape, and the first outer permanent magnet slot 111b and the second outer permanent magnet slot 112b are symmetrical about the d-axis and arranged in a V-shape. That is, the first permanent magnet slot group I has a double-layer structure, with both the inner and outer permanent magnet slots arranged in a V-shape, making the first permanent magnet slot group I a double V-shaped permanent magnet slot group arrangement, which makes the magnetic field distribution more uniform, reduces edge effects, and enhances overall performance.

[0060] Similarly, the third permanent magnet slot 113 includes a third inner permanent magnet slot 113a and a third outer permanent magnet slot 113b located outside the third inner permanent magnet slot 113a; the fourth permanent magnet slot 114 includes a fourth inner permanent magnet slot 114a and a fourth outer permanent magnet slot 114b located outside the fourth inner permanent magnet slot 114a. The third inner permanent magnet slot 113a and the fourth inner permanent magnet slot 114a are symmetrical about the d-axis and arranged in a V-shape, and the third outer permanent magnet slot 113b and the fourth outer permanent magnet slot 114b are symmetrical about the d-axis and arranged in a V-shape. That is, the second permanent magnet slot group II is also a double-layer structure, with both the inner and outer permanent magnet slots arranged in a V-shape, making the second permanent magnet slot group II a double V-shaped permanent magnet 120 slot group arrangement, which makes the magnetic field distribution more uniform, reduces edge effects, and enhances the overall performance.

[0061] Accordingly, the outer end of the first inner permanent magnet groove 111a is connected to the outer end of the fourth inner permanent magnet groove 114a to form the first strip-shaped magnetic isolation groove 117, and the outer end of the second inner permanent magnet groove 112a is connected to the outer end of the third inner permanent magnet groove 113a to form the second strip-shaped magnetic isolation groove 118.

[0062] Of any two first notches 115 that are symmetrical about the d-axis, one first notch 115 is located on the outer circumference region of the rotor core between the first inner permanent magnet slot 111a and the first outer permanent magnet slot 111b, and the other first notch 115 is located on the outer circumference region of the rotor core between the second inner permanent magnet slot 112a and the second outer permanent magnet slot 112b, so as to facilitate processing and improve space utilization.

[0063] Among any two second gaps 116 that are symmetric about the d-axis, one of the second gaps 116 is located on the outer circumferential region of the rotor core between the third inner permanent magnet slot 113a and the third outer permanent magnet slot 113b, and the other second gap 116 is located on the outer circumferential region of the rotor core between the fourth inner permanent magnet slot 114a and the fourth outer permanent magnet slot 114b, so as to facilitate processing and improve space utilization.

[0064] The first strip-shaped magnetic isolation slot 117, the second strip-shaped magnetic isolation slot 118, the first gap 115, and the second gap 116 need to select appropriate sizes to avoid a significant increase in the magnetic resistance of the main magnetic flux path, which affects the performance of the motor. In addition, the mechanical properties of the rotor also need to be considered to avoid stress concentration.

[0065] In some embodiments of the present invention, the inner and outer diameters of the first strip-shaped magnetic isolation slot 117 satisfy: 0 < R1 - R2 < 2.4 * gap, and the inner and outer diameters of the second strip-shaped magnetic isolation slot 118 satisfy: 0 < R3 - R4 < 2.4 * gap; where R1 is the outer diameter of the first strip-shaped magnetic isolation slot 117, R2 is the inner diameter of the first strip-shaped magnetic isolation slot 117, R3 is the outer diameter of the second strip-shaped magnetic isolation slot 118, R4 is the inner diameter of the second strip-shaped magnetic isolation slot 118, and gap is the air gap of the motor, 0 < gap < 2.

[0066] In some embodiments of the present invention, the length A2 of the permanent magnet 120 in the first inner-layer permanent magnet slot 111a satisfies: 0.65*(π / P - 2*D1 / R0)*R0 < A2 < 0.85*(π / P - 2*D1 / R0)*R0, where D1 is the distance from the outer end of the first inner-layer permanent magnet slot 111a to the q-axis (i.e., the distance from one end of the first strip-shaped magnetic isolation slot 117 to the q-axis), P is the number of pole pairs of the motor, and R0 is the outer diameter of the rotor; the width B2 of the permanent magnet 120 in the fourth inner-layer permanent magnet slot 114a satisfies: 0.5*D1 < B2 < 1.5*D1; the included angle V2 between the first inner-layer permanent magnet slot 111a and the second inner-layer permanent magnet slot 112a satisfies: 180° / P < V2 < 360° / P + 20°; the included angle V4 between the third inner-layer permanent magnet slot 113a and the fourth inner-layer permanent magnet slot 114a satisfies: 0 < V4 - V2 < 30°; the included angle V1 between the first outer-layer permanent magnet slot 111b and the second outer-layer permanent magnet slot 112b satisfies: 145° < V1 < 180°; the included angle V3 between the third outer-layer permanent magnet slot 113b and the fourth outer-layer permanent magnet slot 114b satisfies: 0 < V4 - V3 < 30°; D2 is the distance from the outer end of the fourth inner-layer permanent magnet slot 114a to the q-axis (i.e., the distance from the other end of the first strip-shaped magnetic isolation slot 117 to the q-axis), and D1 and D2 satisfy: 2.3 < D1 / D2 < 6.3, and 0 < D2 < 2*gap, where gap is the air gap of the motor; D3 is the distance from the outer end of the first outer-layer permanent magnet slot 111b to the q-axis, D4 is the distance from the outer end of the fourth outer-layer permanent magnet slot 114b to the q-axis, and D3 and D4 satisfy: 2 < D3 / D1 < 5, 0 < D3 - D4 < 0.5*A1, where A1 is the length of the permanent magnet 120 in the first outer-layer permanent magnet slot 111b.

[0067] In some embodiments of the present invention, as shown in FIGS. 2 and 3, the first notch 115 is located between the d-axis and the q-axis adjacent to the d-axis, and along the circumferential direction from the d-axis to the q-axis, the depth of the first notch 115 gradually increases.

[0068] Similarly, the second notch 116 is located between the d-axis and the q-axis adjacent to the d-axis, and along the circumferential direction from the d-axis to the q-axis, the depth of the second notch 116 gradually increases.

[0069] Through the above dimension design, the cross-sections of the first notch 115 and the second notch 116 are approximately ax-shaped, which can effectively optimize the magnetic resistance of the magnetic isolation bridges of the inner and outer layer permanent magnet slots, make the air-gap magnetic field distribution more sinusoidal, thereby reducing the harmonic content of the air-gap magnetic field, reducing the alternating frequency of the magnetic field, and further reducing the iron loss.

[0070] Further, the width G1 and depth F1 of the first notch 115 satisfy: 1 < F1 / G1 < 0.5*B1 / gap + 0.4; the width G2 and depth F2 of the second notch 116 satisfy: 1 < F2 / G2 < 0.85*B1 / gap + 0.4. Wherein, gap < G1 < 1.8*gap, 0 < G1 - G2 < 0.5*Gap + 0.2, B1 is the width of the permanent magnet 120 in the fourth outer permanent magnet slot 114b, and gap is the motor air gap.

[0071] Referring to FIG. 4, in some further embodiments of the present invention, the number of the first permanent magnet slots 111 in each first permanent magnet slot group I is one, and the number of the second permanent magnet slots 112 is one; the number of the third permanent magnet slots 113 in each second permanent magnet slot group II is one, and the number of the fourth permanent magnet slots 114 is one. That is, the first permanent magnet slot group I is of a single V-shaped structure, and the second permanent magnet slot group II is of a single V-shaped structure.

[0072] Referring to FIG. 5, in some further embodiments of the present invention, only two first notches 115 symmetrical about the d-axis are formed on the outer circumference of the rotor core between the first permanent magnet slot 111 and the second permanent magnet slot 112, and no second notch 116 is provided on the outer circumference of the rotor core between the third permanent magnet slot 113 and the fourth permanent magnet slot 114. Alternatively, no first notch 115 is provided on the outer circumference of the rotor core between the first permanent magnet slot 111 and the second permanent magnet slot 112, and only two second notches 116 symmetrical about the d-axis are formed on the outer circumference of the rotor core between the third permanent magnet slot 113 and the fourth permanent magnet slot 114.

[0073] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A motor rotor, characterized in that, The rotor body includes a rotor core, on which multiple first permanent magnet slot groups and multiple second permanent magnet slot groups are formed. The first and second permanent magnet slot groups are staggered along the circumference of the rotor core. Each first permanent magnet slot group includes a first and a second permanent magnet slot arranged symmetrically about the d-axis in a V-shape. Each second permanent magnet slot group includes a third and a fourth permanent magnet slot arranged symmetrically about the d-axis in a V-shape. The first and fourth permanent magnet slots are adjacent to each other, and the second and third permanent magnet slots are adjacent to each other. The outer ends of the first and fourth permanent magnet slots communicate with each other to form a first strip-shaped magnetic isolation slot. The outer end of the magnet slot communicates with the outer end of the third permanent magnet slot to form a second strip-shaped magnetic isolation slot. The first and second strip-shaped magnetic isolation slots pass through the q-axis direction and are located in the outer circumferential region of the rotor core. A strip-shaped magnetic isolation bridge is formed on the rotor core outside the first and second strip-shaped magnetic isolation slots. Two first notches symmetrical about the d-axis are formed on the outer circumference of the rotor core between the first and second permanent magnet slots, and / or two second notches symmetrical about the d-axis are formed on the outer circumference of the rotor core between the third and fourth permanent magnet slots. The first notches are located between the d-axis and the q-axis, and the depth of the first notches gradually increases from the d-axis along the circumference towards the q-axis. The second notch is located between the d-axis and the q-axis, and its depth gradually increases from the d-axis along the circumference towards the q-axis. Permanent magnets are respectively installed in the first, second, third, and fourth permanent magnet slots. The first permanent magnet slot includes a first inner permanent magnet slot and a first outer permanent magnet slot located outside the first inner permanent magnet slot. The second permanent magnet slot includes a second inner permanent magnet slot and a second outer permanent magnet slot located outside the second inner permanent magnet slot. The first inner permanent magnet slot and the second inner permanent magnet slot are symmetrical about the d-axis and arranged in a V-shape. The first outer permanent magnet slot and the second outer permanent magnet slot are symmetrical about the d-axis and arranged in a V-shape. The first and second inner permanent magnet slots are arranged in a V-shape. The third permanent magnet slot includes a third inner permanent magnet slot and a third outer permanent magnet slot located outside the third inner permanent magnet slot. The fourth permanent magnet slot includes a fourth inner permanent magnet slot and a fourth outer permanent magnet slot located outside the fourth inner permanent magnet slot. The third inner permanent magnet slot and the fourth inner permanent magnet slot are symmetrical about the d-axis and arranged in a V-shape. The outer ends of the first inner permanent magnet slot and the fourth inner permanent magnet slot are connected to form the first strip-shaped magnetic isolation slot. The outer ends of the second inner permanent magnet slot and the third inner permanent magnet slot are connected to form the second strip-shaped magnetic isolation slot.Of the two first notches, one is located on the outer circumference of the rotor core between the first inner permanent magnet slot and the first outer permanent magnet slot, and the other is located on the outer circumference of the rotor core between the second inner permanent magnet slot and the second outer permanent magnet slot; of the two second notches, one is located on the outer circumference of the rotor core between the third inner permanent magnet slot and the third outer permanent magnet slot, and the other is located on the outer circumference of the rotor core between the fourth inner permanent magnet slot and the fourth outer permanent magnet slot.

2. The motor rotor according to claim 1, characterized in that, The first permanent magnet slot group and the second permanent magnet slot group are asymmetric, and the first notch and the second notch are asymmetric.

3. The motor rotor according to claim 2, characterized in that, The number of the first permanent magnet slots in each of the first permanent magnet slot groups is one, and the number of the second permanent magnet slots is one; the number of the third permanent magnet slots in each of the second permanent magnet slot groups is one, and the number of the fourth permanent magnet slots is one.

4. The motor rotor according to claim 1, characterized in that, The inner and outer diameters of the first strip-shaped magnetic isolation slot satisfy: 0 < R1 - R2 < 2.4 * gap, and the inner and outer diameters of the second strip-shaped magnetic isolation slot satisfy: 0 < R3 - R4 < 2.4 * gap; where, R1 is the outer diameter of the first strip-shaped magnetic isolation slot, R2 is the inner diameter of the first strip-shaped magnetic isolation slot, R3 is the outer diameter of the second strip-shaped magnetic isolation slot, R4 is the inner diameter of the second strip-shaped magnetic isolation slot, gap is the air gap of the motor, and 0 < gap < 2.

5. The motor rotor according to claim 1, characterized in that, The length A2 of the permanent magnet in the first inner-layer permanent magnet slot satisfies: 0.65 * (π / P - 2 * D1 / R0) * R0 < A2 < 0.85 * (π / P - 2 * D1 / R0) * R0, where D1 is the distance from the outer end of the first inner-layer permanent magnet slot to the q-axis, P is the number of pole pairs of the motor, and R0 is the outer diameter of the rotor; the width B2 of the permanent magnet in the fourth inner-layer permanent magnet slot satisfies: 0.5 * D1 < B2 < 1.5 * D1; the included angle V2 between the first inner-layer permanent magnet slot and the second inner-layer permanent magnet slot satisfies: 180° / P < V2 < 360° / P + 20°; the included angle V4 between the third inner-layer permanent magnet slot and the fourth inner-layer permanent magnet slot satisfies: 0 < V4 - V2 < 30°; the included angle V1 between the first outer-layer permanent magnet slot and the second outer-layer permanent magnet slot satisfies: 145° < V1 < 180°; the included angle V3 between the third outer-layer permanent magnet slot and the fourth outer-layer permanent magnet slot satisfies: 0 < V4 - V3 < 30°; D2 is the distance from the outer end of the fourth inner-layer permanent magnet slot to the q-axis, and D1 and D2 satisfy: 2.3 < D1 / D2 < 6.3, and 0 < D2 < 2 * gap, where gap is the air gap of the motor; D3 is the distance from the outer end of the first outer-layer permanent magnet slot to the q-axis, D4 is the distance from the outer end of the fourth outer-layer permanent magnet slot to the q-axis, and D3 and D4 satisfy: 2 < D3 / D1 < 5, 0 < D3 - D4 < 0.5 * A1, where A1 is the length of the permanent magnet in the first outer-layer permanent magnet slot.

6. The motor rotor according to claim 1, characterized in that, The width G1 and depth F1 of the first notch satisfy: 1 < F1 / G1 < 0.5 * B1 / gap + 0.4; the width G2 and depth F2 of the second notch satisfy: 1 < F2 / G2 < 0.85 * B1 / gap + 0.4; where, gap < G1 < 1.8 * gap, 0 < G1 - G2 < 0.5 * Gap + 0.2, B1 is the width of the permanent magnet in the fourth outer-layer permanent magnet slot, and gap is the air gap of the motor.

7. An electric motor, characterized in that, Including the motor rotor according to any one of claims 1 - 6.

8. A vehicle, characterized in that, Including the motor according to claim 7.

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