Permanent magnet synchronous motor rotor structure and processing method for new energy vehicles

Abstract

The present invention provides a permanent magnet synchronous motor rotor structure for new energy vehicles, which is applied to the technical field of new energy vehicle motors. The present invention also relates to a method for processing the permanent magnet synchronous motor rotor structure for new energy vehicles. The rotor body (1) of the permanent magnet synchronous motor rotor structure for new energy vehicles is provided with a plurality of groups of magnet parts (3), each group of magnet parts (3) includes magnet grooves (4), and the outer surface of the rotor body (1) is provided with a plurality of groups of groove components (6), and the two inclined grooves (11) of each group of groove components (6) are arranged between the two magnet grooves (4) of the corresponding group of magnet parts (3). The permanent magnet synchronous motor rotor structure for new energy vehicles according to the present invention does not change the core area of ​​the main magnetic circuit, but changes the flow path of the main magnetic flux, thereby effectively weakening the harmonic content of the air gap magnetic density, reducing the noise and order noise caused by the excitation force, and comprehensively improving the NVH performance of the drive motor.

Description

Technical Field

[0001] The present invention belongs to the technical field of new energy vehicle motors, and more specifically, relates to a permanent magnet synchronous motor rotor structure for new energy vehicles. The present invention also relates to a permanent magnet synchronous motor rotor structure processing method for new energy vehicles. Background Art

[0002] At present, the NVH problem in the new energy vehicle industry is quite obvious. The drive motor, as the main noise source, is the main component that needs to be improved. Unlike the low-frequency noise of traditional cars, the high-frequency noise in the drive motor will make people feel extremely uncomfortable, among which the order noise related to the number of poles and slots of the drive motor is more prominent. In EV motors with high output density requirements, a rotor with a slightly V-shaped magnet embedded arrangement is generally used. This type of rotor is aimed at the circular rotor core, and the purpose is to prevent the short-circuit magnetic flux inside the rotor. The proposal implements a rotor structure with various shapes of magnetic isolation bridges. This rotor structure can improve the sinusoidality of the air gap flux density, reduce torque pulsation, increase reluctance torque, etc. by adjusting the distribution of magnetic poles (such as magnet arrangement angle, magnet spacing, and pole size (pole arc coefficient). However, the air gap flux density in the above method is easy to be rectangular. Since the rectangular wave contains many harmonic components, there is a problem that the stator electromagnetic force component that does not help to generate electromagnetic torque is easily increased. Generally, if this electromagnetic excitation & excitation mode is close to the natural vibration frequency & natural mode of the stator, it may cause a large noise. For example, the pole slot combination of the drive motor is 8 poles and 48 slots. Under load, the torque pulsation of the motor's speed frequency 48th order (relative to the motor speed) will be relatively large. In addition, the radial electromagnetic force of the 48th order component of the speed frequency can cause 0th order vibration in space, which may produce a large excitation force. In this way, a relatively obvious 48th order noise will be generated during the operation of the motor. Summary of the invention

[0003] The technical problem to be solved by the present invention is: in view of the shortcomings of the prior art, a permanent magnet synchronous motor rotor structure for new energy vehicles is provided which has a simple structure and changes the flow path of the main magnetic flux by improving the rotor body without changing the core area of ​​the main magnetic circuit, thereby effectively weakening the harmonic content of the air gap magnetic density, reducing the torque pulsation and radial electromagnetic excitation force of the corresponding harmonic order, reducing the noise caused by the excitation force, and improving the NVH performance of the motor.

[0004] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is:

[0005] The present invention is a permanent magnet synchronous motor rotor structure for new energy vehicles, comprising a rotor body, a middle opening axially penetrating the rotor body is arranged on the rotor body, a plurality of groups of magnet parts are arranged at intervals along an axial circle of the rotor body, each group of magnet parts comprises two magnet grooves arranged in a V-shape, a hole-shaped part is arranged between the two magnet grooves of each group of magnet parts, a plurality of groups of groove assemblies are arranged along an axial circle on the outer surface of the rotor body, two inclined grooves of each group of groove assemblies are arranged between the two magnet grooves of a corresponding group of magnet parts, and the two grooves are both arranged to extend in the direction of the hole-shaped part.

[0006] The two inclined grooves of each group of groove components are configured to be in a V-shaped structure, and the hole-shaped portion is configured to be in a triangular structure.

[0007] The hole-shaped portion includes side lines I, II and III, and the magnet slots 4 of each group of magnet parts include outer side lines.

[0008] The edge line I of the hole-shaped portion between the two magnet slots of each group of magnet parts is close to the outer surface of the rotor body, the edge line II is close to the outer edge line of one magnet slot of the group of magnet parts, and the edge line III is close to the outer edge line of another magnet slot of the group of magnet parts.

[0009] The edge line II of the hole-shaped portion between the two magnet slots of each group of magnet parts is arranged parallel to the outer edge line of one magnet slot of the group of magnet parts, and the edge line III of the hole-shaped portion between the two magnet slots of each group of magnet parts is arranged parallel to the outer edge line of another magnet slot of the group of magnet parts.

[0010] The two inclined grooves of each groove assembly are located at two sides of a hole-shaped portion, and each groove includes a groove inner line.

[0011] The inner side line of each groove of each groove assembly group is arranged in parallel with the outer side line of a magnet slot of the corresponding magnet part.

[0012] The distance between the edge line II of the hole-shaped portion between the two magnet grooves of each group of magnet parts and the outer edge line of a magnet groove of the group of magnet parts is, the distance between the edge line III of the hole-shaped portion between the two magnet grooves of each group of magnet parts and the outer edge line of another magnet groove of the group of magnet parts is a, the distance between the inner side line of the groove of each group of groove assemblies and the outer side line of a corresponding magnet groove is b, the width dimension of each groove is c, and the depth dimension of each groove is d.

[0013] The distance b between the inner side line of the groove of each groove assembly 6 and the outer side line of a corresponding magnet groove is: 0.5a≤b≤a, and the depth dimension d of each groove is: 2c≤d≤4c.

[0014] The present invention also relates to a method for processing the rotor structure of a permanent magnet synchronous motor for new energy vehicles. The method for processing the rotor structure of a permanent magnet synchronous motor for new energy vehicles includes groove processing, and the steps of groove processing are: 1) processing a preliminary recessed groove on a rotor body 1 to form a preliminary groove, and the preliminary groove includes an inner groove line and an outer groove line; 2) forming a sharp angle structure between the outer groove line and the outer surface of the rotor body 1; 3) chamfering the sharp angle structure to form a groove; 4) chamfering each preliminary groove in turn.

[0015] By adopting the technical solution of the present invention, the following beneficial effects can be obtained:

[0016] The permanent magnet synchronous motor rotor structure for new energy vehicles described in the present invention is provided with multiple groups of magnet parts on the rotor body, each group of magnet parts includes two magnet slots, and two grooves are provided between the two magnet slots of each group of magnet parts, and a hole-shaped part is provided between the two grooves. In this way, the respective structures, respective arrangement positions, and relative relationships of the magnet slots, grooves, and hole-shaped parts are changed, so that the core area of ​​the main magnetic circuit will not be changed, but the flow path of the main magnetic flux can be changed, thereby effectively weakening the harmonic content rate of the air gap magnetic density and reducing the noise of the drive motor. The structure of the present invention is to open a groove near each magnet slot on the rotor body, and the groove is parallel to the edge line of the magnet slot. The permanent magnet synchronous motor rotor structure for new energy vehicles described in the present invention has a simple structure. By improving the rotor body, the core area of ​​the main magnetic circuit is not changed, but the flow path of the main magnetic flux is changed, thereby effectively weakening the harmonic content rate of the air gap magnetic density, reducing the torque pulsation and radial electromagnetic excitation force of the corresponding harmonic order, reducing the noise caused by the excitation force, and the order noise, and comprehensively improving the NVH performance of the drive motor. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The following is a brief description of the contents and symbols in the drawings of this specification:

[0018] Figure 1 This is a schematic diagram of the overall structure of the permanent magnet synchronous motor rotor structure for new energy vehicles according to the present invention;

[0019] Figure 2 It is a partial structural schematic diagram of the A portion of the rotor structure of the permanent magnet synchronous motor for new energy vehicles according to the present invention;

[0020] Figure 3 It is a schematic diagram of the local structure of the permanent magnet synchronous motor rotor structure for new energy vehicles according to the present invention before the rounding process is performed;

[0021] Figure 4 It is a schematic diagram of the local structure when the size relationship of each part of the permanent magnet synchronous motor rotor structure for new energy vehicles according to the present invention is marked;

[0022] Figure 5 A comparison diagram of the overall torque fluctuation amplitude between the permanent magnet synchronous motor rotor structure for new energy vehicles of the present invention and an embodiment of the prior art (original solution);

[0023] Figure 6 This is a comparison chart of 48 torque fluctuation amplitudes of the permanent magnet synchronous motor rotor structure for new energy vehicles of the present invention and the prior art, both of which are 8-pole 48-slot embodiments;

[0024] Figure 7 A comparison diagram of 48-order radial forces at different positions of the permanent magnet synchronous motor rotor structure for new energy vehicles of the present invention and the prior art embodiment of 8 poles and 48 slots;

[0025] Figure 8 A comparison chart of the overall sound pressure level of the permanent magnet synchronous motor rotor structure for new energy vehicles according to the present invention and an embodiment of the prior art;

[0026] Fig. 9 This is a comparison chart of the 48th-order sound pressure level of the permanent magnet synchronous motor rotor structure for new energy vehicles of the present invention and the prior art embodiment, both of which have 8 poles and 48 slots;

[0027] The marks in the accompanying drawings are respectively: 1. rotor body; 2. middle opening; 3. magnet part; 4. magnet slot; 5. hole-shaped part; 6. groove assembly; 7. edge line I; 8. edge line II; 9. edge line III; 10. outer edge line; 11. groove; 12. inner line of groove; 13. preliminary groove; 14. outer line of groove; 15. sharp angle structure; 16. inner edge line. DETAILED DESCRIPTION

[0028] The following is a further detailed description of the specific implementation of the present invention, such as the shape, structure, mutual position and connection relationship between the various components involved, the function and working principle of each part, etc., through the description of the embodiments with reference to the accompanying drawings:

[0029] As attached Figure 1 -Attached Fig. 9As shown, the present invention is a permanent magnet synchronous motor rotor structure for new energy vehicles, including a rotor body 1, a middle opening 2 axially penetrating the rotor body 1 is arranged on the rotor body 1, and multiple groups of magnet parts 3 are arranged in gaps along the axial circle of the rotor body 1, each group of magnet parts 3 includes two magnet grooves 4 arranged in a V shape, and a hole-shaped part 5 is arranged between the two magnet grooves 4 of each group of magnet parts 3, and multiple groups of groove components 6 are arranged along the axial circle of the outer surface of the rotor body 1, and two inclined grooves 11 of each group of groove components 6 are arranged between the two magnet grooves 4 of a corresponding group of magnet parts 3, and the two grooves 11 are both arranged to extend in the direction of the hole-shaped part 5. In the above structure, multiple groups of magnet parts are arranged on the rotor body, each group of magnet parts includes two magnet grooves, and two grooves are arranged between the two magnet grooves of each group of magnet parts, and a hole-shaped part is arranged between the two grooves. In this way, the respective structures, respective layout positions, and relative relationships of the magnet slots, grooves, and hole-shaped portions are changed. In this way, the core area of ​​the main magnetic circuit will not be changed, but the flow path of the main magnetic flux can be changed, thereby effectively weakening the harmonic content of the air gap magnetic density and reducing the noise of the drive motor. The structure of the present invention is to open a groove on the rotor body near each magnet slot, and the groove is parallel to the edge line of the magnet slot. The permanent magnet synchronous motor rotor structure for new energy vehicles described in the present invention has a simple structure, does not change the core area of ​​the main magnetic circuit, but changes the flow path of the main magnetic flux, effectively weakens the harmonic content of the air gap magnetic density, reduces the torque pulsation and radial electromagnetic excitation force of the corresponding harmonic order, reduces the noise caused by the excitation force, and improves the NVH performance of the motor.

[0030] The two inclined grooves 11 of each groove assembly 6 are arranged in a V-shaped structure, and the hole-shaped portion 5 is arranged in a triangular structure. The above structure sets the relative position of the groove and each magnet slot of the magnet portion, so that a corresponding relationship is formed between the magnets arranged in the magnet slots and the corresponding grooves. When the drive motor is working, the flow path of the main magnetic flux is changed, thereby effectively weakening the harmonic content of the air gap magnetic density and reducing noise.

[0031] The hole-shaped portion 5 includes edge lines Ⅰ7, Ⅱ8, and Ⅲ9, and the magnet slots 4 of each group of magnet parts 3 include outer edge lines 10. The edge line Ⅰ7 of the hole-shaped portion 5 between the two magnet slots 4 of each group of magnet parts 3 is close to the outer surface of the rotor body 1, the edge line Ⅱ8 is close to the outer edge line 10 of one magnet slot 4 of the group of magnet parts 3, and the edge line Ⅲ9 is close to the outer edge line 10 of another magnet slot 4 of the group of magnet parts 3. In the above structure, each hole-shaped portion is surrounded by two magnet slots of a group of magnet parts and two grooves of a group of groove components, so that each hole-shaped portion and the corresponding group of magnet parts and the corresponding group of groove components establish a structural relationship. In this way, when the drive motor is working, the groove intervenes to change the flow path of the main magnetic flux.

[0032] The sideline II8 of the hole-shaped portion 5 between the two magnet slots 4 of each group of magnet parts 3 is arranged in parallel with the outer sideline 10 of one magnet slot 4 of the group of magnet parts 3, and the sideline III9 of the hole-shaped portion 5 between the two magnet slots 4 of each group of magnet parts 3 is arranged in parallel with the outer sideline 10 of another magnet slot 4 of the group of magnet parts 3. The two inclined grooves 11 of each group of groove components 6 are located on both sides of a hole-shaped portion 5, and each groove 11 includes a groove inner side line 12. The groove inner side line 12 of each groove 11 of each group of groove components 6 is arranged in parallel with the outer side line 10 of one magnet slot 4 of the corresponding magnet part 3. In the above structure, each magnet slot of each group of magnet parts corresponds to a groove of the corresponding groove component. The outer side line of the magnet slot corresponding to the groove inner side line of each groove is parallel. In this way, when the drive motor is working, the groove effectively intervenes, changes the flow path of the main magnetic flux, and weakens the harmonic content of the air gap magnetic density.

[0033] Each magnet slot 4 of each magnet part 3 also includes an inner side line 16, and the inner side line of each magnet slot 4 of each magnet part 3 is close to the inner side line of another magnet slot, and a hole-shaped portion is provided between the two inner side lines of the two magnet slots of each magnet part. In the above structure, different hole-shaped portions are respectively connected to the magnetic circuit, which effectively weakens the harmonic content rate of the air gap magnetic density.

[0034] The distance between the sideline II8 of the hole-shaped portion 5 between the two magnet grooves 4 of each group of magnet parts 3 and the outer sideline 10 of one magnet groove 4 of the group of magnet parts 3 is a, the distance between the sideline III9 of the hole-shaped portion 5 between the two magnet grooves 11 of each group of magnet parts 6 and the outer sideline 10 of another magnet groove 4 of the group of magnet parts 3 is a, the distance between the inner sideline 12 of the groove 4 of each group of groove components 3 and the outer sideline 10 of a corresponding magnet groove 4 is b, the width dimension of each groove 11 is c, and the depth dimension of each groove 11 is d. The dimension b of the distance between the inner sideline 12 of the groove 11 of each group of groove components 6 and the outer sideline 10 of a corresponding magnet groove 4 is: 0.5a≤b≤a, and the depth dimension d of each groove 11 is: 2c≤d≤4c. The above structure sets the distance dimensions of the grooves, magnet grooves, and hole-shaped portions. The distance size relationship between the groove, magnet slot and hole-shaped portion is applicable to the rotor structure of drive motors of different models and sizes. When the drive motor is working, the distance size relationship can effectively change the flow path of the main magnetic flux, effectively weaken the harmonic content of the air gap magnetic density, and make the drive motor work in the best state, so that the torque pulsation and radial electromagnetic excitation force of the corresponding harmonic order are reduced, and the noise caused by the excitation force is reduced.

[0035] The present invention also relates to a method for processing the rotor structure of a permanent magnet synchronous motor for new energy vehicles, which has simple steps and does not change the core area of ​​the main magnetic circuit, but changes the flow path of the main magnetic flux, weakens the harmonic content of the air gap magnetic density, reduces the torque pulsation and radial electromagnetic excitation force of the corresponding harmonic order, reduces the noise caused by the excitation force, and improves the NVH performance of the motor.

[0036] The method for machining the rotor structure of a permanent magnet synchronous motor for new energy vehicles includes groove machining, and the steps of groove machining are: 1) machining a preliminary recessed groove on the rotor body 1 to form a preliminary groove 13, the preliminary groove 13 including a groove inner line 12 and a groove outer line 14; 2) forming a sharp angle structure 15 between the groove outer line 14 and the outer surface of the rotor body 1; 3) performing a rounding process on the sharp angle structure 15 to form a groove 11; 4) performing a rounding process on each preliminary groove 13 in turn. In the above steps, the sharp angle structure is rounded, which can reduce damage to the mold during the motor manufacturing process, thereby extending the service life of the mold.

[0037] The applicable scope of the structure of the present invention is not limited to the 8-pole 48-slot structure shown in the embodiment.

[0038] The permanent magnet synchronous motor rotor structure for new energy vehicles described in the present invention is provided with multiple groups of magnet parts on the rotor body, each group of magnet parts includes two magnet slots, and two grooves are provided between the two magnet slots of each group of magnet parts, and a hole-shaped part is provided between the two grooves. In this way, the respective structures, respective arrangement positions, and relative relationships of the magnet slots, grooves, and hole-shaped parts are changed, so that the core area of ​​the main magnetic circuit will not be changed, but the flow path of the main magnetic flux can be changed, thereby effectively weakening the harmonic content rate of the air gap magnetic density and reducing the noise of the drive motor. The structure of the present invention is to open a groove near each magnet slot on the rotor body, and the groove is parallel to the edge line of the magnet slot. The permanent magnet synchronous motor rotor structure for new energy vehicles described in the present invention has a simple structure. By improving the rotor body, the core area of ​​the main magnetic circuit is not changed, but the flow path of the main magnetic flux is changed, thereby effectively weakening the harmonic content rate of the air gap magnetic density, reducing the torque pulsation and radial electromagnetic excitation force of the corresponding harmonic order, reducing the noise caused by the excitation force, and the order noise, and comprehensively improving the NVH performance of the drive motor.

[0039] The present invention is described above by way of example in conjunction with the accompanying drawings. It is obvious that the specific implementation of the present invention is not limited to the above-mentioned method. As long as various improvements are made using the method concept and technical solution of the present invention, or the concept and technical solution of the present invention are directly applied to other occasions without improvement, they are all within the protection scope of the present invention.

Claims

1. A permanent magnet synchronous motor rotor structure for new energy vehicles, characterized in that: The invention comprises a rotor body (1), wherein a middle opening (2) penetrating the rotor body (1) in the axial direction is provided on the rotor body (1), a plurality of groups of magnet parts (3) are provided at intervals along an axial circle on the rotor body (1), each group of magnet parts (3) comprises two magnet grooves (4) arranged in a V-shape, a hole-shaped part (5) is provided between the two magnet grooves (4) of each group of magnet parts (3), and a plurality of groups of groove components (6) are provided along an axial circle on the outer surface of the rotor body (1), two inclined grooves (11) of each group of groove components (6) are arranged between the two magnet grooves (4) of a corresponding group of magnet parts (3), and the two grooves (11) are both provided with a structure extending in the direction of the hole-shaped part (5); The hole-shaped portion (5) comprises a side line I (7), a side line II (8), and a side line III (9), and the magnet slots (4) of each group of magnet portions (3) respectively comprise an outer side line (10); The edge line I (7) of the hole-shaped portion (5) between the two magnet slots (4) of each group of magnet parts (3) is close to the outer surface of the rotor body (1), the edge line II (8) is close to the outer edge line (10) of one magnet slot (4) of the group of magnet parts (3), and the edge line III (9) is close to the outer edge line (10) of another magnet slot (4) of the group of magnet parts (3); The distance between the edge line II (8) of the hole-shaped portion (5) between the two magnet grooves (4) of each group of magnet parts (3) and the outer edge line (10) of one magnet groove (4) of the group of magnet parts (3) is a, the distance between the edge line III (9) of the hole-shaped portion (5) between the two magnet grooves (4) of each group of magnet parts (3) and the outer edge line (10) of another magnet groove (4) of the group of magnet parts (3) is a, the distance between the inner side line (12) of the groove (11) of each group of groove components (6) and the outer side line (10) of a corresponding magnet groove (4) is b, the width dimension of each groove (11) is c, and the depth dimension of each groove (11) is d; The dimension b of the distance between the inner side line (12) of the groove (11) of each groove assembly (6) and the outer side line (10) of a corresponding magnet groove (4) is: 0.5a≤b≤a, and the depth dimension d of each groove (11) is: 2c≤d≤4c.

2. The permanent magnet synchronous motor rotor structure for new energy vehicles according to claim 1 is characterized in that: The two inclined grooves (11) of each group of groove assemblies (6) are configured to be in a V-shaped structure, and the hole-shaped portion (5) is configured to be in a triangular structure.

3. The permanent magnet synchronous motor rotor structure for new energy vehicles according to claim 1, characterized in that: The side line II (8) of the hole-shaped portion (5) between the two magnet slots (4) of each group of magnet portions (3) is arranged in parallel with the outer side line (10) of one magnet slot (4) of the group of magnet portions (3); and the side line III (9) of the hole-shaped portion (5) between the two magnet slots (4) of each group of magnet portions (3) is arranged in parallel with the outer side line (10) of another magnet slot (4) of the group of magnet portions (3).

4. The permanent magnet synchronous motor rotor structure for new energy vehicles according to claim 1 or 2, characterized in that: The two inclined grooves (11) of each group of groove components (6) are located on both sides of a hole-shaped portion (5), and each groove (11) comprises a groove inner line (12).

5. The permanent magnet synchronous motor rotor structure for new energy vehicles according to claim 4 is characterized in that: The groove inner side line (12) of each groove (11) of each group of groove assemblies (6) is arranged in parallel with the outer side line (10) of a magnet slot (4) of the corresponding magnet part (3).

6. A method for machining a permanent magnet synchronous motor rotor structure for a new energy vehicle, characterized in that: The method for machining the rotor structure of a permanent magnet synchronous motor for a new energy vehicle comprises groove machining, wherein the groove machining steps are as follows: 1) machining a preliminary recessed groove on a rotor body (1) to form a preliminary groove (13), wherein the preliminary groove (13) comprises a groove inner line (12) and a groove outer line (14); 2) forming a sharp angle structure (15) between the groove outer line (14) and the outer surface of the rotor body (1); 3) performing a chamfering process on the sharp angle structure (15) to form a groove (11); and 4) performing a chamfering process on each preliminary groove (13) in turn.

Images