Rotor punching sheet with high reluctance ratio, rotor core, driving motor and vehicle

Abstract

The utility model discloses a rotor punching sheet with high reluctance ratio, which comprises a punching sheet main body and a magnetic pole unit arranged on the punching sheet main body, the magnetic pole unit comprises a first layer of permanent magnet slots, a second layer of permanent magnet slots and rectangular magnetic isolation holes, permanent magnets penetrate through the first layer of permanent magnet slots and the second layer of permanent magnet slots, and the rectangular magnetic isolation holes are arranged on the first layer of permanent magnet slots and the second layer of permanent magnet slots. The first layer of permanent magnet slots comprises two permanent magnet slots, the second layer of permanent magnet slots comprises two permanent magnet slots, the two permanent magnet slots are distributed in a V shape, the first layer of permanent magnet slots and the rectangular magnetic isolation holes are located between the two permanent magnet slots, and the first layer of permanent magnet slots and the rectangular magnetic isolation holes are oppositely arranged. According to the rotor punching sheet with the high magnetic resistance ratio, the salient pole ratio of a motor is improved through the optimal design of the magnetic poles, so that the magnetic resistance torque of the motor is improved, the use amount of the rare earth permanent magnets is reduced, and the purpose of reducing the cost is achieved. The utility model also discloses a rotor core, a driving motor and a vehicle.

Description

TECHNICAL FIELD

[0001] The utility model belongs to motor technical field, specifically, the utility model relates to a high magnetic resistance proportion rotor lamination, rotor core, driving motor and vehicle. BACKGROUND

[0002] Built-in rare earth permanent magnet synchronous motor is widely used in vehicle driving motor due to its high torque density, high power density and high efficiency performance advantages. However, the price of rare earth raw materials is expensive, which leads to high cost of rare earth permanent magnet motor.

[0003] Permanent magnet synchronous motor will induce high back electromotive force (BEMF) in the stator winding at high speed, which has the risk of breaking down the controller, limiting the maximum speed of the motor. Therefore, under the premise of maintaining the same motor torque density, reducing the back electromotive force at high speed becomes an important indicator of motor design.

[0004] During motor operation, the interaction of rotor magnetic field harmonics and stator magnetic field harmonics of each order will produce radial force varying with space and time, causing motor vibration and electromagnetic noise (NVH, Noise Vibration Harshness). In built-in permanent magnet synchronous motor, there is a common problem of high vibration and noise due to the influence of stator slotting.

[0005] The patent document with publication number CN106230138A discloses a motor lamination, which comprises a lamination body, a winding post around the lamination body, and a magnetic strip provided at the connection end of the lamination body. The technical solution disclosed in the patent document cannot solve the above-mentioned technical problems. UTILITY MODEL CONTENT

[0006] The utility model aims to solve at least one of the technical problems existing in the prior art. To this end, the utility model provides a high magnetic resistance proportion rotor lamination, which aims to reduce cost.

[0007] In order to achieve the above-mentioned purpose, the utility model adopts the technical scheme of: a high magnetic resistance proportion rotor lamination, which comprises a lamination body and a magnetic pole unit provided on the lamination body, the magnetic pole unit comprises a first layer of permanent magnet slot, a second layer of permanent magnet slot and a rectangular magnetic isolation hole, a permanent magnet passes through the first layer of permanent magnet slot and the second layer of permanent magnet slot, the second layer of permanent magnet slot comprises two permanent magnet slots, the two permanent magnet slots are distributed in a V shape, the first layer of permanent magnet slot and the rectangular magnetic isolation hole are located between the two permanent magnet slots, and the first layer of permanent magnet slot and the rectangular magnetic isolation hole are arranged oppositely.

[0008] The first layer of permanent magnet slot is located between the rectangular magnetic isolation hole and the outer edge of the rotor lamination.

[0009] An auxiliary slot is provided on the outer edge of the rotor lamination.

[0010] The first layer of permanent magnet slot is a "one" type permanent magnet slot structure, and the second layer of permanent magnet slot is a "V" type permanent magnet slot structure, and the permanent magnet slot structure is symmetrical about a direct axis.

[0011] The first layer of permanent magnet slot comprises a first magnetic isolation hole and a first permanent magnet slot section, the first magnetic isolation hole is provided with two, and the first permanent magnet slot section is located between the two first magnetic isolation holes, and a permanent magnet passes through the first permanent magnet slot section.

[0012] The second layer of permanent magnet slot comprises a second magnetic isolation hole, a third magnetic isolation hole and a second permanent magnet slot section, the second permanent magnet slot section is located between the second magnetic isolation hole and the third magnetic isolation hole, and a permanent magnet passes through the second permanent magnet slot section.

[0013] The utility model also provides a rotor core, including high magnetic resistance proportion rotor punching sheet of the utility model.

[0014] The utility model also provides a driving motor, including rotor core of the utility model.

[0015] The utility model also provides a vehicle, including driving motor of the utility model.

[0016] The high magnetic resistance proportion rotor punching sheet of the utility model improves the salient pole ratio of the motor through the optimization design of the magnetic pole, thereby improving the reluctance torque, reducing the amount of rare earth permanent magnet, and achieving the purpose of reducing the cost. BRIEF DESCRIPTION OF DRAWINGS

[0017] The present specification includes the following drawings, and the shown contents are respectively:

[0018] Figure 1 It is the structure schematic diagram of rotor core of example one;

[0019] Figure 2 It is the front view of rotor core of example one;

[0020] Figure 3 It is the front view of magnetic pole unit of example one;

[0021] Figure 4 It is the size marking drawing of first layer permanent magnet slot of example one;

[0022] Figure 5 It is the size marking drawing of second layer permanent magnet slot of example one;

[0023] Figure 6 It is the local structure schematic diagram of rotor punching sheet of example one;

[0024] Figure 7 It is the front view of rotor core of example two;

[0025] Figure 8 is a front view of the magnetic pole unit of Example Two;

[0026] Figure 9 is a dimensioned view of the first layer of permanent magnet slots of Example Two;

[0027] Figure 10 is a dimensioned view of the second layer of permanent magnet slots of Example Two;

[0028] Figure 11 is a dimensioned view of the magnetic pole unit of Example Two;

[0029] Figure 12 is a front view of the rotor core of Example Three;

[0030] In the figure, reference numerals are: 10, rotor core; 200, rotor lamination; 210, lamination body; 220, shaft hole; 222, shaft hole core; 230, magnetic pole unit; 2310, first mounting slot; 2311, first flux gap; 2312, first permanent magnet slot segment; 2313, first flux bridge; 2314, first rotor yoke; 2320, second mounting slot; 2321, second flux gap; 2322, third flux gap; 2323, rectangular flux gap; 2324, second permanent magnet slot segment; 2325, second flux bridge; 2326, third flux bridge; 2327, second rotor yoke; 2420, first layer of permanent magnet slots; 2440, second layer of permanent magnet slots; 250, auxiliary slot. DETAILED DESCRIPTION

[0031] The specific embodiments of the present application will be further described in detail with reference to the accompanying drawings, and the purpose of the description of the embodiments is to help the skilled in the art to have a more complete, accurate and in-depth understanding of the concept and technical scheme of the present application, and to facilitate its implementation.

[0032] It should be noted that in the following embodiments, the "first", "second" and "third" do not represent an absolute distinction in structure and / or function, nor represent the execution order, but only for the convenience of description.

[0033] Example One

[0034] As Figures 1 to 6As shown, the embodiment provides a rotor lamination with high magnetic reluctance ratio, which comprises a lamination body 210 and a plurality of magnetic pole units 230 arranged on the lamination body 210, and all the magnetic pole units 230 are uniformly distributed in the circumferential direction on the lamination body 210. The magnetic pole unit 230 comprises a first layer of permanent magnet slot 2420, a second layer of permanent magnet slot 2440, and a rectangular magnetic gap hole 2323, the first layer of permanent magnet slot 2420 and the second layer of permanent magnet slot 2440 pass through the permanent magnet, the second layer of permanent magnet slot 2440 comprises two permanent magnet slots, the two permanent magnet slots are V-shapedly distributed, the first layer of permanent magnet slot 2420 and the rectangular magnetic gap hole 2323 are located between the two permanent magnet slots, and the first layer of permanent magnet slot 2420 and the rectangular magnetic gap hole 2323 are oppositely arranged.

[0035] Specifically, as shown in the drawings, Figures 1 to 3 The first layer of permanent magnet slot 2420 is located between the rectangular magnetic gap hole 2323 and the outer edge of the rotor lamination. The first layer of permanent magnet slot 2420 is a "one" type permanent magnet slot structure, and the first layer of permanent magnet slot 2420 is symmetrical about the straight axis. The first layer of permanent magnet slot 2420 is close to the outer edge of the rotor lamination, the second layer of permanent magnet slot 2440 is located on the inner side of the first layer of permanent magnet slot 2420 away from the edge of the rotor lamination, and the rectangular magnetic gap hole 2323 is located at the middle position of the two symmetrically arranged permanent magnet slots of the second layer of permanent magnet slot 2440.

[0036] As shown in the drawings, Figures 1 to 3 The first layer of permanent magnet slot 2420 comprises a first magnetic gap hole 2311 and a first permanent magnet slot segment 2312, the first magnetic gap hole 2311 is arranged in two, the first permanent magnet slot segment 2312 is located between the two first magnetic gap holes 2311, the first permanent magnet slot segment 2312 passes through the permanent magnet, and the two first magnetic gap holes 2311 are symmetrical about the straight axis.

[0037] As shown in the drawings, Figures 1 to 3 The second layer of permanent magnet slot 2440 comprises two permanent magnet slots which are symmetrical about the straight axis and are arranged at intervals, the permanent magnet slot of the second layer of permanent magnet slot 2440 comprises a second magnetic gap hole 2321, a third magnetic gap hole 2322 and a second permanent magnet slot segment 2324, the second permanent magnet slot segment 2324 is located between the second magnetic gap hole 2321 and the third magnetic gap hole 2322, and the second permanent magnet slot segment 2324 passes through the permanent magnet.

[0038] As shown in the drawings, Figures 1 to 3 The rectangular magnetic gap hole 2323 is rectangular in shape and symmetrical about the straight axis. The rectangular magnetic gap hole 2323 is designed to be rectangular in order to ensure the size of the magnetic gap bridge (reduce magnetic flux leakage) and ensure the strength requirement of the rotor.

[0039] As shown in the drawings, Figures 1 to 3 In this embodiment, the magnetic pole unit 230 is arranged in 12.

[0040] As shown in Figures 1 to 3 the connection part between the first layer permanent magnet slot 2420 and the outer edge of the rotor lamination is the first magnetic isolation bridge 2313, the connection part between the second layer permanent magnet slot 2440 and the outer edge of the rotor lamination is the second magnetic isolation bridge 2325, the connection part between the rectangular magnetic isolation hole 2323 and the magnetic isolation hole on both sides of the end of the second layer permanent magnet slot 2440 is the third magnetic isolation bridge 2326, the two first magnetic isolation bridges 2313 are symmetrical about the direct axis, the two second magnetic isolation bridges 2325 are symmetrical about the direct axis, and the two third magnetic isolation bridges 2326 are symmetrical about the direct axis. The connection part between the first layer permanent magnet slot 2420 and the outer edge of the rotor lamination is the first rotor magnetic yoke 2314, and the first rotor magnetic yoke 2314 is located between the two first magnetic isolation bridges 2313. The connection part between the first layer permanent magnet slot 2420 and the rectangular magnetic isolation hole 2323 is the second rotor magnetic yoke 2327, and the second rotor magnetic yoke 2327 is located between the two permanent magnet slots of the second layer permanent magnet slot 2440.

[0041] As shown in Figure 4 and Figure 5 the included angle of the arc segment between the two first magnetic isolation bridges 2313 corresponding to the first layer permanent magnet slot 2420 is the first pole arc angle θ1, the included angle between the two permanent magnet slots of the second layer permanent magnet slot 2440 is θ2, and the included angle of the arc segment between the two second magnetic isolation bridges 2325 between the second layer permanent magnet slot 2440 and the edge of the rotor lamination is θ3.

[0042] The relationship between the length L of each single segment of the motor rotor core and the stacking height H of the rotor core is L=H / M, and there is a certain skew angle γ between the two adjacent segments.

[0043] The slot angle is defined as α1=360 / p, the rotor radius is R9, and the first pole arc angle θ1 and the above motor slot angle α1 should satisfy:

[0044] 1.5α1≤θ1≤2.2α1.

[0045] The bias distance H1 of the first permanent magnet and the width W1 of the permanent magnet should satisfy:

[0046] 0.5W1≤H1≤0.75W1;

[0047] The second pole arc angle θ3 and the above motor slot angle α1 should satisfy:

[0048] 5α1≤θ3≤6α1.

[0049] The included angle θ2 of the second layer permanent magnet slot 2440 should satisfy: 80°≤θ2≤100°.

[0050] The distance H2 between the second permanent magnet and the center of the rotor punching should satisfy: 0.65R≤H2≤0.85R.

[0051] The dimensions of the first permanent magnet embedded in the first layer of permanent magnet slots 2420 and the second permanent magnet embedded in the second layer of permanent magnet slots 2440 should meet the following requirements:

[0052] 1.1≤L1 / L2≤1.3, 1≤W1 / W2≤1.2;

[0053] The thickness W2 of the second permanent magnet is greater than or equal to 2.7 mm and less than or equal to 5 mm; the width L2 of the second permanent magnet is greater than or equal to 9 mm and less than or equal to 16 mm.

[0054] The skew angles γ and α1 of two adjacent core sections should satisfy:

[0055] 0°≤γ≤α1*(M / 2-1) / (M / 2), M is an even number;

[0056] 0°≤γ≤α1*((M+1) / 2-1) / ((M+1) / 2), where M is an odd number.

[0057] The implementation principle of this embodiment is as follows:

[0058] 1. To meet the requirements of reducing the no-load line back electromotive force (BEMF) and reducing costs, the length of the permanent magnet can be adjusted (reducing the amount of permanent magnets used) to reduce the effective magnetic flux in the air gap;

[0059] 2. For the "V+1" type magnetic pole structure, the D-axis magnetic circuit is the magnetization direction of the permanent magnet, and the Q-axis (quadrature axis) magnetic circuit can be divided into: the "V" part close to the rotating shaft, the yoke part between the "V" and the "I", and the yoke part between the "I" and the rotor edge. Reasonable design of the rotor yoke, increasing the magnetic resistance on the D-axis (direct-axis) magnetic circuit, reducing the D-axis inductance, reducing the magnetic resistance of the Q-axis magnetic circuit, and increasing the Q-axis inductance can enable the motor to maintain a high salient pole ratio (Lq / Ld), thereby enabling the motor to obtain a higher reluctance torque ratio and improve the torque density of the motor. At the same time, while ensuring the strength of the rotor, optimizing the size of the magnetic isolation bridge, reducing leakage magnetic flux, and improving the utilization rate of the permanent magnets can improve the torque output capacity.

[0060] In this embodiment, if Figure 4 As shown, the distance H1 between the first layer of permanent magnet slots 2420 and the outer edge of the rotor lamination has been optimized. By increasing the thickness of the first rotor yoke 2314 in this section, the salient pole ratio is reduced by 1.18%, torque is reduced by 1.62%, and the efficiency percentage greater than 80% is increased by 2.4%. The relevant data before and after the optimization are shown in Table 1.

[0061] Table 1

[0062] Before optimization After optimization D-axis inductance 0.0377 mH 0.03787 Q-axis inductance 0.09412 mH 0.09343 Salient pole ratio 2.4966 2.4671 Peak torque 178.5 Nm 175.6 Nm >80% efficiency share 82.71％ 85.11％

[0063] Biasing the permanent magnet will reduce the salient pole ratio and sacrifice a certain amount of torque, but the advantage is that it can increase the proportion of the motor's high-efficiency area. The highest efficiency area is distributed in the weak magnetic area after the inflection point, which improves the weak magnetic performance of the motor. When the motor operates at high speed, it is more efficient and consumes less energy.

[0064] The high reluctance ratio rotor punching of the above structure has the following advantages:

[0065] 1. The output torque of the built-in permanent magnet synchronous motor is composed of permanent magnet torque and reluctance torque. By improving the salient pole ratio of the motor (by optimizing the magnetic circuit design), the reluctance torque is increased, the amount of rare earth permanent magnets used is reduced, and the cost is reduced.

[0066] 2. Reduce the effective magnetic flux in the air gap and achieve lower back EMF at the same torque density and maximum speed through optimized design of the magnetic poles;

[0067] 3. Optimize the magnetic pole design so that the motor can still maintain certain salient pole characteristics under high-speed conditions and provide a certain reluctance torque in the field weakening stage, thereby improving the motor output efficiency and reducing energy consumption;

[0068] 4. Rotor shaping: Rationally design the auxiliary slots 250 on the rotor surface to effectively reduce the harmonic content in the air gap magnetic field, improve the sinusoidality of the air gap magnetic density, improve the torque pulsation of the motor, reduce the radial electromagnetic force caused by harmonics, and improve NVH performance.

[0069] This embodiment also provides a rotor core, including rotor punchings with a high magnetic reluctance ratio of the above structure.

[0070] This embodiment also provides a driving motor, including a rotor core of the above structure.

[0071] This embodiment also provides a vehicle, comprising a drive motor of the above structure.

[0072] Example 2

[0073] like Figures 7 to 10 As shown, in this embodiment, auxiliary grooves 250 are provided on the outer edge of the rotor punching, multiple auxiliary grooves 250 are provided and all auxiliary grooves 250 are evenly distributed along the circumferential direction, the angle between two adjacent auxiliary grooves 250 is θ4, and the two adjacent auxiliary grooves 250 are symmetrical about the straight axis.

[0074] Assuming the radius of the auxiliary groove 250 is r, the angle θ4 between two adjacent auxiliary grooves 250 should satisfy:

[0075] 0.05R≤r≤0.15R, 1.2θ1≤θ4≤θ3.

[0076] The torque ripple of the motor is related to the sinusoidal degree of the air gap magnetic field, the worse the sinusoidal degree of the motor air gap magnetic flux density is, the higher the harmonic content is, the larger the torque ripple of the motor is, and the higher the NVH risk is; by reasonably designing the geometric size of the magnetic pole, the rotor is shaped, and the auxiliary slot 250 is reasonably arranged, the harmonic content in the air gap magnetic field can be effectively reduced, the sinusoidal degree of the air gap magnetic flux density is improved, the radial electromagnetic force is reduced, and the NVH risk is reduced.

[0077] After the auxiliary slot 250 is arranged, the harmonic content of the air gap magnetic field can be greatly improved; at the same time, by the rotor skew pole, the harmonic content in the magnetic field can be further effectively weakened, and the vibration and noise of the motor are improved. Combined with the two measures, the harmonic content of the no-load back electromotive force can be reduced to below 1%.

[0078] As shown in Figure 7 In this embodiment, 12 magnetic pole units 230 are arranged in total.

[0079] Example three

[0080] As shown in Figure 11 In this embodiment, 10 magnetic pole units 230 are arranged in total.

[0081] The utility model has been described exemplarily above in combination with the drawings. Apparently, the specific implementation of the utility model is not limited by the above-mentioned mode. As long as various non-essential improvements are made by adopting the method concept and technical scheme of the utility model, or the above-mentioned concept and technical scheme of the utility model are directly applied to other occasions without improvement, they are all within the protection scope of the utility model.

Claims

1. A high reluctance ratio rotor lamination, comprising a lamination body and a magnetic pole unit arranged on the lamination body, characterized in that: The magnetic pole unit comprises a first layer of permanent magnet slots, a second layer of permanent magnet slots and a rectangular magnetic isolation hole, the first layer of permanent magnet slots and the second layer of permanent magnet slots pass through permanent magnets, the second layer of permanent magnet slots comprises two permanent magnet slots, the two permanent magnet slots are distributed in a V shape, the first layer of permanent magnet slots and the rectangular magnetic isolation hole are located between the two permanent magnet slots, and the first layer of permanent magnet slots and the rectangular magnetic isolation hole are oppositely arranged.

2. The high reluctance occupancy ratio rotor lamination of claim 1, wherein: The first layer of permanent magnet slots is located between the rectangular magnetic isolation hole and the outer edge of the rotor lamination.

3. The high reluctance occupancy ratio rotor lamination of claim 1, wherein: An auxiliary slot is arranged on the outer edge of the rotor lamination.

4. The high reluctance ratio rotor lamination of any one of claims 1 to 3, wherein: The first layer of permanent magnet slots is a "I" type permanent magnet slot structure, the second layer of permanent magnet slots is a "V" type permanent magnet slot structure, and the permanent magnet slot structures are symmetrical about a direct axis.

5. The high reluctance ratio rotor lamination of any one of claims 1 to 3, wherein: The first layer of permanent magnet slots comprises first magnetic isolation holes and a first permanent magnet slot section, the first magnetic isolation holes are two, the first permanent magnet slot section is located between the two first magnetic isolation holes, and the first permanent magnet slot section passes through a permanent magnet.

6. The high reluctance ratio rotor lamination of any one of claims 1 to 3, wherein: The second layer of permanent magnet slots comprises second magnetic isolation holes, third magnetic isolation holes and a second permanent magnet slot section, the second permanent magnet slot section is located between the second magnetic isolation holes and the third magnetic isolation holes, and the second permanent magnet slot section passes through a permanent magnet.

7. A rotor core characterized by: A rotor lamination with a high magnetic resistance ratio is provided, which comprises any one of claims 1 to 6.

8. A drive motor characterised by: A rotor core is provided, which comprises claim 7.

9. Vehicle, characterized in that: A driving motor is provided, which comprises claim 8.

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