A built-in permanent magnet rotor punching sheet for improving permanent magnet utilization

Abstract

The present invention discloses a built-in permanent magnet rotor punching sheet for improving the utilization rate of permanent magnets, including a sheet body, the sheet body is provided with a magnet mounting structure, the magnet mounting structure includes a first magnet mounting groove and two second magnet mounting grooves, two first magnetic isolation grooves and two second magnetic isolation grooves located on the sheet body, the two second magnet mounting grooves are located on the same side of the first magnet mounting groove, the two second magnet mounting grooves are symmetrically arranged with the first magnet mounting groove as the center, the second magnet mounting groove is inclined, and the end of the second magnet mounting groove close to the center of the sheet body is inclined in the direction close to the first mounting groove. The beneficial effects achieved by the present invention are: the magnetic circuit is guided to extend along the gap between the first magnetic isolation groove and the second magnetic isolation groove, the eddy current loss generated in the rotor punching sheet is reduced, the radial magnetic force is reduced, and the advantage of small eddy current loss of the permanent magnet is achieved.

Description

Technical Field

[0001] The invention relates to the technical field of motor rotor punching sheet structures, and in particular to a built-in permanent magnet rotor punching sheet capable of improving permanent magnet utilization. Background Art

[0002] my country has vigorously developed new energy vehicles and put forward the dual carbon goals of energy conservation and emission reduction, "carbon peak" and "carbon neutrality". New energy products in the automotive market have developed rapidly. New energy vehicles include pure electric vehicles, fuel cell electric vehicles and hybrid electric vehicles. Hybrid electric vehicles are an effective combination of traditional internal combustion engine vehicles and electric vehicles. By combining the advantages of both, they can greatly reduce fuel consumption while taking into account driving performance. Hybrid electric vehicles have strong market competitiveness. The motors required by hybrid electric vehicles need to have high power density, high efficiency and excellent dynamic performance, while taking into account low cost.

[0003] The motor consists of two parts: the rotor and the stator. The motor rotor is the rotating part in the motor. The rotor is provided with an iron core, and the permanent magnet is embedded in the iron core. The iron core is assembled by overlapping multiple rotor punchings. The magnetic field generated by the stator coil when it is energized drives the permanent magnet and the iron core to rotate, thereby driving the rotor to rotate in the motor.

[0004] The Chinese invention patent with announcement number CN109412300B discloses a tangential motor, a motor rotor and a rotor core. A plurality of permanent magnet slots are arranged on the rotor core along its circumferential direction, and the rotor core has a rotor pole located between two adjacent permanent magnet slots; wherein, a first magnetic isolation hole and a second magnetic isolation hole are arranged on the rotor pole, and the first magnetic isolation hole is located on the radial center line of the rotor pole to reduce the magnetic flux at the place where the magnetic flux is relatively dense, and to even out the magnetic flux of the rotor pole as a whole. At the same time, the width of the first magnetic isolation hole gradually increases from the outside to the inside to increase the magnetic resistance at the place where the magnetic poles are relatively dense inside the rotor pole, so that the magnetic flux at the radial center line of the rotor pole is evenly dispersed. In addition, the second magnetic isolation hole is distributed on both sides of the first magnetic isolation hole along the circumference of the rotor core, and the second magnetic isolation hole cooperates with the first magnetic isolation hole to further even out the magnetic flux on the rotor pole and improve the direction of the magnetic flux. In this way, the waveform of the air gap magnetic density is comprehensively improved, the proportion of harmonics is reduced, and the vibration and noise of the motor are reduced.

[0005] The existing motor rotor punching structure is simple, the reluctance torque utilization rate is low, and eddy current loss is easily generated in the rotor punching, which increases the radial magnetic force and affects the working performance of the motor. Therefore, there is a technical problem of high eddy current loss of permanent magnets in the existing technology. Summary of the invention

[0006] In order to solve the above technical problems, the purpose of the present invention is to provide an internal permanent magnet rotor punching sheet for improving the utilization rate of permanent magnets, which includes a sheet body. The internal permanent magnet rotor punching sheet for improving the utilization rate of permanent magnets has the advantage of small eddy current loss of permanent magnets.

[0007] In order to achieve the above-mentioned invention object, the technical solution adopted by the present invention is as follows:

[0008] A built-in permanent magnet rotor punching sheet for improving the utilization rate of permanent magnets includes a sheet body, the sheet body is provided with a magnet mounting structure, the magnet mounting structure includes a first magnet mounting groove and two second magnet mounting grooves, two first magnetic isolation grooves and two second magnetic isolation grooves located on the sheet body, the two second magnet mounting grooves are located on the same side of the first magnet mounting groove, the two second magnet mounting grooves are symmetrically arranged with the first magnet mounting groove as the center, the second magnet mounting groove is inclined, the end of the second magnet mounting groove close to the center position of the sheet body is inclined in the direction close to the first mounting groove, the first magnetic isolation groove and the second magnetic isolation groove are respectively connected to the two ends of the second magnet mounting groove, and the first magnetic isolation groove and the second magnetic isolation groove correspond to the second magnet mounting groove one by one.

[0009] Through such an arrangement: the first permanent magnet and the second permanent magnet are respectively installed in the first magnet mounting groove and the second magnet mounting groove, and the magnetic poles of the first permanent magnet and the second permanent magnet are arranged relative to each other, so that the first permanent magnet and the second permanent magnet attract each other on the sheet body, thereby being able to guide the magnetic circuit to pass through the first permanent magnet and the second permanent magnet in sequence, and the dispersedly arranged first permanent magnet and second permanent magnet can guide the magnetic circuit to extend along the gap between the first magnetic isolation groove and the second magnetic isolation groove at different positions, thereby reducing the eddy current loss generated in the rotor punching, reducing the radial magnetic force, and achieving the advantage of small eddy current loss of the permanent magnet.

[0010] Preferably, the first magnetic isolation groove is located at one end of the second magnet mounting groove close to the center of the sheet body, and the first magnetic isolation groove extends toward the center of the sheet body.

[0011] Through such an arrangement, the eddy current loss generated at one end of the second magnet installation slot close to the center of the sheet body is reduced.

[0012] Preferably, the second magnetic isolation groove is located at an end of the second magnet mounting groove away from the center of the sheet body, and the second magnetic isolation groove extends along the circumference of the sheet body.

[0013] Through such an arrangement, the leakage magnetic field can be reduced.

[0014] Preferably, the magnet mounting structure further comprises two first auxiliary grooves arranged on the sheet body, the two first auxiliary grooves are respectively located at two ends of the first magnet mounting groove, and the two first auxiliary grooves are symmetrically arranged with the first magnet mounting groove as the center.

[0015] Through such an arrangement, the leakage magnetic field can be reduced.

[0016] Preferably, the magnet mounting structure also includes two second auxiliary grooves arranged on the sheet body and two third auxiliary grooves arranged on the sheet body, the first auxiliary grooves, the second auxiliary grooves and the third auxiliary grooves correspond to each other one by one, the second auxiliary grooves are located on the side of the first auxiliary groove away from the first magnet mounting groove, the third auxiliary grooves are located on the side of the second auxiliary groove away from the first magnet mounting groove, and the second auxiliary grooves are staggered with the connecting line between the first auxiliary grooves and the third auxiliary grooves.

[0017] Through such an arrangement, the leakage magnetic field can be reduced.

[0018] Preferably, a plurality of the magnet mounting structures are provided, and the plurality of magnet mounting structures are evenly distributed circumferentially on the sheet.

[0019] Through such a setting: Improve motor performance.

[0020] Preferably, the sheet body is provided with a plurality of first radial magnetic isolation grooves, wherein the first radial magnetic isolation grooves are located between adjacent magnet mounting structures, and the first radial magnetic isolation grooves extend in a direction close to the center position of the sheet body.

[0021] Through such an arrangement, the leakage magnetic field is reduced, thereby achieving the advantage of small eddy current loss of the permanent magnet.

[0022] Preferably, the sheet body is provided with a plurality of inner magnetic isolation grooves, which correspond one-to-one to a plurality of first radial magnetic isolation grooves, and the inner magnetic isolation grooves are located at one end of the first radial magnetic isolation grooves close to the center of the sheet body. The inner magnetic isolation grooves are triangular in shape as a whole, and the width of the inner magnetic isolation grooves gradually increases along the direction close to the center of the sheet body.

[0023] Through such an arrangement, the leakage magnetic field is reduced, thereby achieving the advantage of small eddy current loss of the permanent magnet.

[0024] Preferably, the sheet body is provided with a plurality of second radial magnetic isolation grooves, the plurality of second radial magnetic isolation grooves are respectively located between a plurality of adjacent inner magnetic isolation grooves, and the second radial magnetic isolation grooves extend toward the center of the sheet body.

[0025] This arrangement can prevent the sheet material between adjacent inner magnetic isolation grooves from being deformed and broken due to insufficient width.

[0026] Preferably, a plurality of the sheet bodies are provided, the axes of the plurality of sheet bodies coincide and fit each other, and the installation angles of the plurality of sheet bodies in the circumferential direction are staggered.

[0027] Through such a setting, the stability of the motor operation is improved and the noise during operation is reduced.

[0028] Compared with the prior art, the present invention has achieved beneficial technical effects:

[0029] 1. The first permanent magnet and the second permanent magnet are respectively installed in the first magnet mounting groove and the second magnet mounting groove. The magnetic poles of the first permanent magnet and the second permanent magnet are arranged opposite to each other, so that the first permanent magnet and the second permanent magnet attract each other on the sheet body, thereby guiding the magnetic circuit to pass through the first permanent magnet and the second permanent magnet in sequence. The dispersedly arranged first permanent magnet and the second permanent magnet can guide the magnetic circuit to extend along the gap between the first magnetic isolation groove and the second magnetic isolation groove at different positions, thereby reducing the eddy current loss generated in the rotor punching sheet, reducing the radial magnetic force, and achieving the advantage of small eddy current loss of the permanent magnet.

[0030] 2. The first magnet mounting slot and the two second magnet mounting slots are arranged in a triangle, so that the first permanent magnet and the second permanent magnet cooperate with the first magnetic isolation slot, the second magnetic isolation slot, the first auxiliary slot, the second auxiliary slot and the third auxiliary slot, so that the Q-axis inductance of the motor is significantly greater than the D-axis inductance, and the magnetic resistance torque generated by the unequal inductances of the D and Q axes is fully utilized, the utilization rate of the first permanent magnet and the second permanent magnet is improved, and the area of ​​the motor with the highest efficiency is increased.

[0031] 3. By setting the first magnetic isolation groove, the second magnetic isolation groove, the first auxiliary groove, the second auxiliary groove and the third auxiliary groove, the magnetic circuit structure is optimized, the air gap magnetic field harmonics of the motor are reduced, the torque fluctuation and the cogging torque are reduced, the leakage magnetic flux is reduced, and the maximum efficiency of the motor is improved.

[0032] 4. A triangular first magnetic isolation groove is set on the inner side of the sheet body to reduce the leakage of magnetic flux to the motor rotor shaft installed at the center of the sheet body, and the hollow structure formed by the first magnetic isolation groove can achieve the effect of ventilation and heat dissipation, thereby dissipating the heat and cooling the sheet body, the first permanent magnet and the second permanent magnet, reducing the temperature of the motor during operation, and reducing the weight of the sheet body and the motor to achieve lightweight. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 It is a structural schematic diagram of a built-in permanent magnet rotor punching sheet for improving the utilization rate of permanent magnets in an embodiment of the present invention;

[0034] Figure 2 is a structural schematic diagram of a magnet installation structure in an embodiment of the present invention;

[0035] Figure 3 Schematic diagram of the structure of the sheet body in the embodiment of the present invention.

[0036] The technical features indicated by the reference numerals are as follows:

[0037] 10. Sheet body; 20. Magnet mounting structure; 21. First magnet mounting slot; 22. Second magnet mounting slot; 23. First magnetic isolation slot; 24. Second magnetic isolation slot; 25. First auxiliary slot; 26. Second auxiliary slot; 27. Third auxiliary slot; 31. First radial magnetic isolation slot; 32. Second radial magnetic isolation slot; 33. Internal magnetic isolation slot; 41. First permanent magnet; 42. Second permanent magnet. DETAILED DESCRIPTION

[0038] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with embodiments, but the scope of protection claimed in the present invention is not limited to the following specific embodiments.

[0039] refer to Figure 1 and Figure 2 A built-in permanent magnet rotor punching sheet for improving the utilization rate of permanent magnets includes a sheet body 10, which is a magnetic conductor. In this embodiment, the sheet body 11 is made of an iron sheet. The sheet body 10 is provided with a magnet mounting structure 20. The magnet mounting structure 20 includes a first magnet mounting groove 21, two second magnet mounting grooves 22, two first magnetic isolation grooves 23, two second magnetic isolation grooves 24, two first auxiliary grooves 25, two second auxiliary grooves 26 and two third auxiliary grooves 27 located on the sheet body 10.

[0040] The two second magnet mounting grooves 22 are located on the same side of the first magnet mounting groove 21, and the two second magnet mounting grooves 22 are symmetrically arranged with the first magnet mounting groove 21 as the center. The second magnet mounting groove 22 is tilted, and the end of the second magnet mounting groove 22 close to the center of the sheet 10 is tilted toward the direction close to the first mounting groove. The first magnetic isolation groove 23 and the second magnetic isolation groove 24 are respectively connected to the two ends of the second magnet mounting groove 22, and the first magnetic isolation groove 23 and the second magnetic isolation groove 24 correspond to the second magnet mounting groove 22 one by one. The first magnetic isolation groove 23 is located at one end of the second magnet mounting groove 22 close to the center of the sheet 10, and the first magnetic isolation groove 23 extends toward the center of the sheet 10. The first magnetic isolation groove 23 extending toward the center of the sheet 10 can block the magnetic circuit of the two second permanent magnets 42 close to the center of the sheet 10, and reduce the eddy current loss generated at one end of the second magnet mounting groove 22 close to the center of the sheet 10.

[0041] The second magnetic isolation groove 24 is located at one end of the second magnet mounting groove 22 away from the center of the sheet 10, and the second magnetic isolation groove 24 extends along the circumference of the sheet 10. The second magnetic isolation groove 24 extending axially toward the sheet 10 can increase the path distance between the magnetic path of the second permanent magnet 42 on the sheet 10 near the remote center and the first permanent magnet 41, blocking the magnetic path of the second permanent magnet 42 near the center of the sheet 10 from directly connecting to the first permanent magnet 41, thereby reducing magnetic leakage.

[0042] The two first auxiliary grooves 25 are respectively located at the two ends of the first magnet mounting groove 21, and the two first auxiliary grooves 25 are symmetrically arranged with the first magnet mounting groove 21 as the center. The first auxiliary grooves 25 at the two ends of the first magnet mounting groove 21 can block the magnetic circuit at the two ends of the first mounting groove, reduce the magnetic leakage phenomenon of the first permanent magnet 41 at the two ends of the first magnet mounting groove 21, and play a role in reducing magnetic leakage. The first auxiliary groove 25, the second auxiliary groove 26 and the third auxiliary groove 27 correspond one to one, the second auxiliary groove 26 is located on the side of the first auxiliary groove 25 away from the first magnet mounting groove 21, and the third auxiliary groove 27 is located on the side of the second auxiliary groove 26 away from the first magnet mounting groove 21. Through the arrangement of the second auxiliary groove 26 and the third auxiliary groove 27, the magnetic circuit at the two ends of the first mounting groove can be further blocked, and the magnetic leakage phenomenon of the first permanent magnet 41 at the two ends of the first magnet mounting groove 21 can be reduced, which plays a role in reducing magnetic leakage. The second auxiliary groove 26 is staggered with the connecting line between the first auxiliary groove 25 and the third auxiliary groove 27, so as to block magnetic paths in different directions at different positions, thereby further reducing magnetic leakage.

[0043] A plurality of magnet mounting structures 20 are provided, and the plurality of magnet mounting structures 20 are evenly distributed around the circumference of the sheet 10. By providing a plurality of magnet mounting structures 20, a plurality of permanent magnets can be installed to improve the performance of the motor. The sheet 10 is provided with a plurality of first radial magnetic isolation grooves 31, and the first radial magnetic isolation grooves 31 are located between adjacent magnet mounting structures 20, and the first radial magnetic isolation grooves 31 extend in a direction close to the center of the sheet 10. By providing the first radial magnetic isolation grooves 31, the magnetic circuit can be blocked between adjacent magnet mounting structures 20, and while ensuring the structural reliability of the sheet 10, the influence of the magnetic circuit between adjacent magnet mounting structures 20 is reduced, thereby reducing magnetic leakage and achieving the advantage of small eddy current loss of the permanent magnet. The sheet 10 is provided with a plurality of inner magnetic isolation grooves 33, which correspond to the plurality of first radial magnetic isolation grooves 31 one by one, and the inner magnetic isolation grooves 33 are located at one end of the first radial magnetic isolation grooves 31 close to the center of the sheet 10. The inner magnetic isolation grooves 33 are triangular in shape as a whole, and the width of the inner magnetic isolation grooves 33 gradually increases along the direction close to the center of the sheet 10. By setting the inner magnetic isolation grooves 33, the magnetic path of the magnet mounting structure 20 in the direction close to the center of the sheet 10 can be blocked, which plays a role in reducing magnetic leakage and achieving the advantage of small eddy current loss of the permanent magnet. The sheet 10 is provided with a plurality of second radial magnetic isolation grooves 32, which are respectively located between a plurality of adjacent inner magnetic isolation grooves 33, and the second radial magnetic isolation grooves 32 extend toward the center of the sheet 10. The second radial magnetic isolation grooves 32 are arranged between adjacent inner magnetic isolation grooves 33, which plays a role in blocking the magnetic path between adjacent inner magnetic isolation grooves 33 and achieving the advantage of small eddy current loss of the permanent magnet. The second radial magnetic isolation grooves 32 extend toward the center of the sheet 10 , thereby ensuring the structural reliability of the sheet 10 and preventing the sheet 10 from being deformed and fractured due to insufficient material width between adjacent inner magnetic isolation grooves 33 .

[0044] refer to Figure 3 A plurality of sheet bodies 10 are provided, the axes of the plurality of sheet bodies 10 coincide with each other and fit together, and the installation angles of the plurality of sheet bodies 10 in the circumferential direction are staggered.

[0045] By using the same permanent magnet and comparing the electromagnetic force at 24 times the frequency between the punching sheet without the first magnetic isolation groove 23, the second magnetic isolation groove 24, the first auxiliary groove 25, the second auxiliary groove 26 and the third auxiliary groove 27 and the built-in permanent magnet rotor punching sheet for improving the utilization rate of the permanent magnet, it can be detected that the radial electromagnetic force of the punching sheet without the first magnetic isolation groove 23, the second magnetic isolation groove 24, the first auxiliary groove 25, the second auxiliary groove 26 and the third auxiliary groove 27 reaches 47586N / m2, while the radial electromagnetic force of the built-in permanent magnet rotor punching sheet for improving the utilization rate of the permanent magnet is only 41846N / m2. Therefore, by setting the first magnetic isolation groove 23, the second magnetic isolation groove 24, the first auxiliary groove 25, the second auxiliary groove 26 and the third auxiliary groove 27, the radial electromagnetic force is reduced and the eddy current loss of the permanent magnet is reduced.

[0046] This embodiment has the following advantages:

[0047] The first permanent magnet 41 and the second permanent magnet 42 are respectively installed in the first magnet mounting groove 21 and the second magnet mounting groove 22. The magnetic poles of the first permanent magnet 41 and the second permanent magnet 42 are arranged relative to each other, so that the first permanent magnet 41 and the second permanent magnet 42 attract each other on the sheet 10, thereby guiding the magnetic circuit to pass through the first permanent magnet 41 and the second permanent magnet 42 in sequence. The dispersedly arranged first permanent magnet 41 and the second permanent magnet 42 can guide the magnetic circuit to extend along the gap between the first magnetic isolation groove 23 and the second magnetic isolation groove 24 at different positions, thereby reducing the eddy current loss generated in the rotor punching, reducing the radial magnetic force, achieving the advantage of small eddy current loss of the permanent magnet, and effectively improving the utilization rate of the permanent magnet.

[0048] The first magnet mounting slot 21 and the two second magnet mounting slots 22 are arranged in a triangle, so that the first permanent magnet 41 and the second permanent magnet 42 cooperate with the first magnetic isolation slot 23, the second magnetic isolation slot 24, the first auxiliary slot 25, the second auxiliary slot 26 and the third auxiliary slot 27, so that the Q-axis inductance of the motor is significantly greater than the D-axis inductance, and the magnetic resistance torque generated by the unequal inductances of the D and Q axes is fully utilized, the utilization rate of the first permanent magnet 41 and the second permanent magnet 42 is improved, and the area of ​​the motor's highest efficiency region is increased.

[0049] By setting the first magnetic isolation groove 23, the second magnetic isolation groove 24, the first auxiliary groove 25, the second auxiliary groove 26 and the third auxiliary groove 27, the magnetic circuit structure is optimized, the air gap magnetic field harmonics of the motor are reduced, the torque fluctuation and the cogging torque are reduced, the leakage flux is reduced, and the maximum efficiency of the motor is improved.

[0050] The two second magnet installation grooves 22 are symmetrically arranged, so that the structure of the sheet body 10 is simple, and the second permanent magnets 42 of the same size can be installed in the two second magnet installation grooves 22. The permanent magnet assembly process is relatively simple, which is convenient for production and assembly.

[0051] A triangular first magnetic isolation groove 23 is arranged on the inner side of the sheet body 10 to reduce magnetic leakage to the motor rotor shaft installed at the center of the sheet body 10, and the hollow structure formed by the first magnetic isolation groove 23 can achieve the effect of ventilation and heat dissipation, thereby dissipating the heat and cooling the sheet body 10, the first permanent magnet 41 and the second permanent magnet 42, thereby reducing the temperature of the motor during operation, and reducing the weight of the sheet body 10 and the motor to achieve lightweight.

[0052] Permanent magnets are installed on multiple sheets 10 that are staggered in the circumferential direction, so that when the built-in permanent magnet rotor punching that improves the utilization rate of the permanent magnets is rotated to different angles, different sheets 10 can be driven to rotate by the magnetic field, so that they can be driven by the magnetic field when rotating to different angles, thereby improving the stability of the motor during operation and reducing the noise during operation.

[0053] According to the disclosure and teaching of the above description, those skilled in the art to which the present invention belongs may also make changes and modifications to the above embodiments. Therefore, the present invention is not limited to the specific embodiments disclosed and described above, and some modifications and changes to the invention should also fall within the scope of protection of the claims of the present invention. In addition, although some specific terms are used in this specification, these terms are only for the convenience of description and do not constitute any limitation to the invention.

Claims

1. A built-in permanent magnet rotor punching sheet for improving permanent magnet utilization, characterized in that: The invention comprises a sheet (10), wherein the sheet (10) is provided with a magnet mounting structure (20), wherein the magnet mounting structure (20) comprises a first magnet mounting groove (21) and two second magnet mounting grooves (22), two first magnetic isolation grooves (23) and two second magnetic isolation grooves (24) located on the sheet (10), wherein the two second magnet mounting grooves (22) are located on the same side of the first magnet mounting groove (21), and the two second magnet mounting grooves (22) are symmetrically arranged with the first magnet mounting groove (21) as the center, wherein the second magnet mounting groove (22) is inclined, wherein one end of the second magnet mounting groove (22) close to the center position of the sheet (10) is inclined in a direction close to the first mounting groove, wherein the first magnetic isolation groove (23) and the second magnetic isolation groove (24) are respectively connected to two ends of the second magnet mounting groove (22), and the first magnetic isolation groove (23) and the second magnetic isolation groove (24) respectively correspond to the second magnet mounting groove (22) one by one.

2. The internal permanent magnet rotor punching sheet for improving permanent magnet utilization according to claim 1 is characterized in that: The first magnetic isolation groove (23) is located at one end of the second magnet installation groove (22) close to the center of the sheet body (10), and the first magnetic isolation groove (23) extends towards the center of the sheet body (10).

3. The internal permanent magnet rotor punching sheet for improving permanent magnet utilization according to claim 1, characterized in that: The second magnetic isolation groove (24) is located at one end of the second magnet mounting groove (22) away from the center of the sheet body (10), and the second magnetic isolation groove (24) extends along the circumference of the sheet body (10).

4. The internal permanent magnet rotor punching sheet for improving permanent magnet utilization according to claim 1, characterized in that: The magnet mounting structure (20) further comprises two first auxiliary grooves (25) arranged on the sheet body (10), the two first auxiliary grooves (25) being respectively located at two ends of the first magnet mounting groove (21), and the two first auxiliary grooves (25) being symmetrically arranged with the first magnet mounting groove (21) as the center.

5. The internal permanent magnet rotor punching sheet for improving permanent magnet utilization according to claim 4, characterized in that: The magnet mounting structure (20) further comprises two second auxiliary grooves (26) arranged on the sheet body (10) and two third auxiliary grooves (27) arranged on the sheet body (10); the first auxiliary groove (25), the second auxiliary groove (26) and the third auxiliary groove (27) correspond to each other one by one; the second auxiliary groove (26) is located on a side of the first auxiliary groove (25) away from the first magnet mounting groove (21); the third auxiliary groove (27) is located on a side of the second auxiliary groove (26) away from the first magnet mounting groove (21); the second auxiliary groove (26) is staggered with a line connecting the first auxiliary groove (25) and the third auxiliary groove (27).

6. The internal permanent magnet rotor punching sheet for improving permanent magnet utilization according to claim 1, characterized in that: A plurality of the magnet mounting structures (20) are provided, and the plurality of magnet mounting structures (20) are evenly distributed around the circumference of the sheet body (10).

7. The internal permanent magnet rotor punching sheet for improving permanent magnet utilization according to claim 6, characterized in that: The sheet body (10) is provided with a plurality of first radial magnetic isolation grooves (31), wherein the first radial magnetic isolation grooves (31) are located between adjacent magnet mounting structures (20), and the first radial magnetic isolation grooves (31) extend in a direction close to the center position of the sheet body (10).

8. The internal permanent magnet rotor punching sheet for improving permanent magnet utilization according to claim 7, characterized in that: The sheet body (10) is provided with a plurality of inner magnetic isolation grooves (33), the plurality of inner magnetic isolation grooves (33) correspond one to one with the plurality of first radial magnetic isolation grooves (31), the inner magnetic isolation grooves (33) are located at one end of the first radial magnetic isolation grooves (31) close to the center of the sheet body (10), the inner magnetic isolation grooves (33) are triangular in shape as a whole, and the width of the inner magnetic isolation grooves (33) gradually increases along the direction close to the center of the sheet body (10).

9. The internal permanent magnet rotor punching sheet for improving permanent magnet utilization according to claim 8, characterized in that: The sheet body (10) is provided with a plurality of second radial magnetic isolation grooves (32), the plurality of second radial magnetic isolation grooves (32) are respectively located between a plurality of adjacent inner magnetic isolation grooves (33), and the second radial magnetic isolation grooves (32) extend toward the center of the sheet body (10).

10. The internal permanent magnet rotor punching sheet for improving permanent magnet utilization according to claim 1, characterized in that: A plurality of the sheet bodies (10) are provided, the axes of the plurality of sheet bodies (10) coincide and fit each other, and the installation angles of the plurality of sheet bodies (10) in the circumferential direction are staggered.

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