Rotor punching sheet, rotor and motor

Abstract

The invention relates to the technical field of motors, and discloses a rotor punching sheet, a rotor and a motor, the rotor punching sheet comprises a punching sheet body, the radial outer end of the punching sheet body on a Q axis is provided with at least one characteristic groove, and the punching sheet body is provided with a first permanent magnet groove and a second permanent magnet groove. The first permanent magnet grooves and the second permanent magnet grooves form a V shape with an opening facing the outer edge of the punching sheet body, and the first permanent magnet grooves, the second permanent magnet grooves and the punching sheet body between the adjacent characteristic grooves form isolation sections; according to the rotor punching sheet provided by the invention, the magnetic conductance of the whole magnetic circuit of the rotor and the magnetic leakage condition of an armature reaction magnetic field are improved, and the demagnetization resistance of the permanent magnets is improved to a certain extent. Compared with the prior art, on the premise of considering the cost and the torque output required by the motor, the risk of irreversible demagnetization of the permanent magnet is reduced, the demagnetization resistance of the permanent magnet is improved, and the operation stability and safety of the permanent magnet synchronous motor are ensured.

Description

Technical Field

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

[0002] Permanent magnet synchronous motors are widely used in military, industrial, and daily life fields due to their simple structure, fast dynamic response, high reliability, high efficiency, and high power density. The magnetic field of a permanent magnet synchronous motor is generated by permanent magnets on the rotor. During the operation of the permanent magnet synchronous motor, the permanent magnets on the rotor are easily irreversibly demagnetized due to the influence of demagnetization current and the high temperature environment inside the motor. The current mainstream methods for preventing permanent magnet demagnetization on the rotor include: (1) increasing the coercive force of the permanent magnet material and improving the ability of the permanent magnet to resist demagnetization current at the same temperature; however, this method will lead to a certain increase in the cost of the permanent magnet synchronous motor; (2) rotor internalization; that is, increasing the thickness of the rotor magnetic isolation slot to keep the permanent magnet away from the outer circle of the rotor, but this method will affect the torque of the permanent magnet synchronous motor. Therefore, how to reduce the risk of irreversible demagnetization of the permanent magnet and improve the ability of the permanent magnet to resist demagnetization, thereby ensuring the operating stability and safety of the permanent magnet synchronous motor while taking into account the cost and the required torque output of the motor, is a technical problem that needs to be solved urgently by those skilled in the art. Summary of the invention

[0003] The purpose of the present invention is to solve the problem that permanent magnets on the rotor of existing permanent magnet synchronous motors are prone to irreversible demagnetization, and to provide a rotor punching sheet that can reduce the risk of irreversible demagnetization of permanent magnets and improve the anti-demagnetization ability of permanent magnets while taking into account the cost and the required torque output of the motor, thereby ensuring the operating stability and safety of the permanent magnet synchronous motor.

[0004] In order to achieve the above-mentioned objectives, the present invention provides a rotor punching sheet, including a punching sheet body, at least one characteristic groove is arranged at the radial outer end of the punching sheet body located on the Q axis, a first permanent magnet groove and a second permanent magnet groove are arranged on the punching sheet body, the first permanent magnet groove and the second permanent magnet groove form a V-shape with an opening toward the outer edge of the punching sheet body, and the punching sheet body between the first permanent magnet groove and the second permanent magnet groove and the characteristic groove at an adjacent position forms an isolation section.

[0005] Preferably, a characteristic groove is provided at the radial outer end of the punch body located on the Q axis, the depth of the characteristic groove is L2, the width of the characteristic groove along the radial direction of the punch body is W2, and the distance between the outer groove wall of the characteristic groove and the outer edge of the punch body is H, wherein L2≤1mm, W2≤1.2mm, 1mm≤H≤3mm.

[0006] Preferably, a first permanent magnet is installed in the first permanent magnet slot, and a second permanent magnet is installed in the second permanent magnet slot. When installed in place, the angle between the first permanent magnet and the second permanent magnet is 70°-120°.

[0007] Preferably, when installed in place, the included angle between the first permanent magnet and the second permanent magnet is 90°.

[0008] Preferably, the length of the first permanent magnet and the second permanent magnet are both 14.4 mm, and the thickness are both 4 mm.

[0009] Preferably, the ends of the first permanent magnet slot and the second permanent magnet slot close to the outer edge of the punch body are respectively provided with a first air slot, and the punch body between the first air slot and the outer edge of the punch body forms a first magnetic isolation bridge.

[0010] Preferably, second air grooves are respectively provided at the ends of the first permanent magnet groove and the second permanent magnet groove that are close to each other, and the punching sheet body between the second air groove of the first permanent magnet groove and the second air groove of the second permanent magnet groove forms a second magnetic isolation bridge.

[0011] Preferably, avoidance grooves are respectively provided in the first permanent magnet slot and the second permanent magnet slot, and the avoidance grooves are provided on inner walls of the first permanent magnet slot and the second permanent magnet slot close to the outer side of the V-shape.

[0012] The present invention also provides a rotor, which has the above-mentioned rotor punching sheet.

[0013] The present invention also provides a motor having the above-mentioned rotor.

[0014] The inventors of the present application discovered that, through the above-mentioned technical solution, specifically by setting at least one characteristic groove at the radial outer end of the punching body located on the Q axis, and forming the punching body between the first permanent magnet groove and the second permanent magnet groove and the characteristic groove at the adjacent position into an isolation segment, the rotor punching with this structural feature improves the magnetic permeability of the entire magnetic circuit of the rotor and the leakage magnetic field of the armature reaction magnetic field, and increases the anti-demagnetization ability of the permanent magnet to a certain extent.

[0015] Furthermore, compared with the prior art, the technical solution provided by the present invention reduces the risk of irreversible demagnetization of permanent magnets and improves the anti-demagnetization ability of permanent magnets while taking into account the cost and the required torque output of the motor, thereby ensuring the operating stability and safety of the permanent magnet synchronous motor. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a structural schematic diagram of a rotor punching provided by the present invention;

[0017] Figure 2 yes Figure 1 A magnified schematic diagram of position A in the middle;

[0018] Figure 3 is a schematic diagram of the structure of the rotor punching provided in Example 1 of the present invention;

[0019] Figure 4 is a schematic diagram of the structure of the rotor punching provided by Example 3 of the present invention;

[0020] Figure 5 is a demagnetization cloud diagram of the permanent magnet in Examples 1-3 of the present invention;

[0021] Figure 6 It is a comparison chart of output torques of Examples 1-3 of the present invention.

[0022] Description of Reference Numerals

[0023] 10. Punching sheet body; 101. Characteristic groove; 102. Isolation section; 11. First permanent magnet groove; 12. Second permanent magnet groove; 13. First air groove; 131. First magnetic isolation bridge; 14. Second air groove; 141. Second magnetic isolation bridge; 15. Avoidance groove; 20. First permanent magnet; 30. Second permanent magnet. DETAILED DESCRIPTION

[0024] The specific implementation of the present invention is described in detail below in conjunction with the accompanying drawings. It should be understood that the specific implementation described here is only used to illustrate and explain the present invention, and is not used to limit the present invention.

[0025] like Figure 1 and Figure 2 As shown, the present invention provides a rotor punching sheet, which includes a punching sheet body 10, at least one characteristic groove 101 is arranged at the radial outer end of the punching sheet body 10 located on the Q axis, and a first permanent magnet groove 11 and a second permanent magnet groove 12 are arranged on the punching sheet body 10, the first permanent magnet groove 11 and the second permanent magnet groove 12 form a V-shape with an opening toward the outer edge of the punching sheet body 10, and the first permanent magnet groove 11 and the second permanent magnet groove 12 and the punching sheet body 10 between the characteristic groove 101 at the adjacent position are formed as an isolation segment 102.

[0026] In the technical solution provided by the present invention, the first permanent magnet slot 11 and the second permanent magnet slot 12 provided on the punching sheet body 10 are used to install permanent magnets. The inventor of the present application found that by providing at least one characteristic slot 101 at the radial outer end of the punching sheet body 10 provided by the present invention located on the Q axis, and the punching sheet body 10 between the first permanent magnet slot 11 and the second permanent magnet slot 12 and the characteristic slot 101 at the adjacent position is formed into an isolation section 102, the rotor punching sheet with this structural feature improves the magnetic permeability of the entire magnetic circuit of the rotor and the leakage of the armature reaction magnetic field, and increases the anti-demagnetization ability of the permanent magnet to a certain extent.

[0027] Compared with the prior art, the present invention only adds a characteristic groove 101 at the radial outer end of the punching body 10 located on the Q axis. This solution overcomes the high cost defect of the prior art using permanent magnets with high coercive force, and also overcomes the influence of the built-in rotor on the torque of the permanent magnet synchronous motor. Under the premise of taking into account the cost and the required torque output of the motor, the risk of irreversible demagnetization of the permanent magnet is reduced, the anti-demagnetization ability of the permanent magnet is improved, and the operating stability and safety of the permanent magnet synchronous motor are ensured.

[0028] It should be noted that in the present invention, the punching body 10 between the first permanent magnet slot 11 and the second permanent magnet slot 12 and the characteristic slot 101 at the adjacent position is formed as an isolation section 102, that is, the first permanent magnet slot 11 and the second permanent magnet slot 12 are spaced apart from the characteristic slot 101 at the adjacent position and are not connected.

[0029] In some embodiments, a characteristic groove 101 is provided at the radial outer end of the punch body 10 located on the Q axis, the depth of the characteristic groove 101 is L2, the width of the characteristic groove 101 along the radial direction of the punch body 10 is W2, and the distance between the outer groove wall of the characteristic groove 101 and the outer edge of the punch body 10 is H, wherein L2≤1mm, W2≤1.2mm, 1mm≤H≤3mm.

[0030] In some embodiments, a first permanent magnet 20 is installed in the first permanent magnet slot 11, and a second permanent magnet 30 is installed in the second permanent magnet slot 12. When installed in place, the angle between the first permanent magnet 20 and the second permanent magnet 30 is 70°-120°. Further preferably, when installed in place, the angle between the first permanent magnet 20 and the second permanent magnet 30 is 90°.

[0031] In a specific implementation of the present invention, the length of the first permanent magnet 20 and the thickness of the second permanent magnet 30 are both 14.4 mm and 4 mm respectively.

[0032] In some embodiments, the ends of the first permanent magnet slot 11 and the second permanent magnet slot 12 close to the outer edge of the punching sheet body 10 are respectively provided with a first air slot 13, and the punching sheet body 10 between the first air slot 13 and the outer edge of the punching sheet body 10 forms a first magnetic isolation bridge 131.

[0033] The rotor punching provided by the present invention has a V-shaped topological structure. By setting a first air slot 13 and correspondingly forming a first magnetic isolation bridge 131, magnetic leakage can be effectively prevented to ensure the output torque of the motor. At the same time, the above structure provided by the present invention is also conducive to ensuring the mechanical strength of the motor rotor.

[0034] It should be noted that in the above structure, the structural dimensions of the first magnetic isolation bridge 131, such as the dimensions along the circumferential direction of the punching sheet body 10 and the dimensions along the radial direction of the punching sheet body 10, can be adaptively designed according to actual conditions to minimize magnetic leakage and ensure the output torque of the motor. The present invention will not be elaborated here.

[0035] In some embodiments, the ends of the first permanent magnet slot 11 and the second permanent magnet slot 12 that are close to each other are respectively provided with second air slots 14, and the punching sheet body 10 between the second air slots 14 of the first permanent magnet slot 11 and the second air slots 14 of the second permanent magnet slot 12 forms a second magnetic isolation bridge 141. By setting the second magnetic isolation bridge 141, magnetic leakage can be prevented and the output torque of the motor can be ensured. At the same time, the above structure provided by the present invention is also conducive to ensuring the mechanical strength of the motor rotor. Accordingly, in the above structure, the structural dimensions of the second magnetic isolation bridge 141, such as the dimensions along the circumferential direction of the punching sheet body 10, and the dimensions along the radial direction of the punching sheet body 10 can be adaptively designed according to actual conditions to minimize magnetic leakage and ensure the output torque of the motor. The present invention will not be elaborated here.

[0036] Combination Figure 1 and Figure 2 As shown, in some embodiments, the first permanent magnet slot 11 and the second permanent magnet slot 12 are respectively provided with an avoidance slot 15, and the avoidance slot 15 is arranged on the inner wall of the first permanent magnet slot 11 and the second permanent magnet slot 12 close to the outer side of the V-shape. The present invention does not specifically limit the shape of the avoidance slot 15, for example, it can be eyebrow-shaped or arc-shaped. The structural design of the avoidance slot 15 can enhance the anti-demagnetization ability of the permanent magnet, reduce the risk of irreversible demagnetization under demagnetization current and high temperature conditions, and the structural design of the avoidance slot 15 can also reduce the chamfer of the permanent magnet, and can be smoothly inserted into the permanent magnet slot even if the permanent magnet is not chamfered.

[0037] The advantages of the rotor punching provided by the present invention are further described below through specific embodiments.

[0038] Example 1

[0039] Combination Figure 3 As shown, the rotor punching provided in this example includes a punching body 10, on which a first permanent magnet slot 11 and a second permanent magnet slot 12 are provided, and the first permanent magnet slot 11 and the second permanent magnet slot 12 form a V-shape with an opening toward the outer edge of the punching body 10; a first permanent magnet 20 is installed in the first permanent magnet slot 11, and a second permanent magnet 30 is installed in the second permanent magnet slot 12. When installed in place, the angle between the first permanent magnet 20 and the second permanent magnet 30 is 90°. The length L of the first permanent magnet 20 and the second permanent magnet 30 are both 14.4 mm, and the thickness W is both 4 mm; when finite element software is used for simulation, the height of the first permanent magnet 20 and the second permanent magnet 30 is 105 mm; in this example, the motor rotor parameters also include OD=107.4 mm.

[0040] Example 2

[0041] Combination Figure 1 As shown, the present example is different from the rotor punching provided in Example 1 in that: in the rotor punching provided in this example, a characteristic groove 101 is provided at the radial outer end of the punching body 10 located on the Q axis, the depth of the characteristic groove 101 is L2, the radial width of the characteristic groove 101 along the punching body 10 is W2, and the distance between the outer groove wall of the characteristic groove 101 and the outer edge of the punching body 10 is H, wherein L2 is 1 mm; W2 is 1.2 mm; H is 1.02 mm; and the remaining structure is the same as that of the rotor punching in Example 1.

[0042] Example 3

[0043] Combination Figure 4 As shown, the difference between this example and the rotor punching provided in Example 2 is that in this example, the depth of the characteristic groove 101 is set to be able to connect to the permanent magnet groove adjacent thereto; the rest of the structure is the same as that of the rotor punching in Example 2.

[0044] The performance of the rotor punchings provided in Examples 1-3 was evaluated by finite element software simulation.

[0045] like Figure 5 The demagnetization cloud diagram and demagnetization situation of the permanent magnet in Example 1-3 are shown. Figure 5It can be clearly seen that the rotor punchings provided in Example 2 make the demagnetization of the permanent magnet show a certain trend of enhanced anti-demagnetization ability compared with Examples 1 and 3. Specifically, the rotor punchings provided in Example 2 improve the anti-demagnetization ability of the permanent magnet by about 0.5%; in Example 3, when there is a characteristic groove 101 at the same position, the depth of the characteristic groove 101 is set to be able to connect to the permanent magnet groove adjacent to it, but the permanent magnet does not show the expected continuous increase in anti-demagnetization ability.

[0046] Combination Figure 6 It can be seen that the output torque and torque fluctuation level of Example 2 are comparable to those of Example 1, while the output torque of Example 3 is significantly reduced. It can be seen that the output torque can only be maintained on the basis of the technical solution provided by the present invention.

[0047] The present invention also provides a rotor, which has the above-mentioned rotor punching sheet.

[0048] The present invention also provides a motor having the above-mentioned rotor.

[0049] The preferred embodiments of the present invention are described in detail above with reference to the accompanying drawings, but the present invention is not limited thereto. Within the technical concept of the present invention, the technical solution of the present invention can be subjected to a variety of simple modifications. In order to avoid unnecessary repetition, the present invention will not further describe various possible combinations. However, these simple modifications and combinations should also be regarded as the contents disclosed by the present invention and belong to the protection scope of the present invention.

Claims

1. A rotor punching, characterized in that: The invention comprises a punch body (10), wherein at least one characteristic groove (101) is arranged at the radial outer end of the punch body (10) located on the Q axis, and a first permanent magnet groove (11) and a second permanent magnet groove (12) are arranged on the punch body (10), wherein the first permanent magnet groove (11) and the second permanent magnet groove (12) form a V-shape with an opening toward the outer edge of the punch body (10), and the punch body (10) between the first permanent magnet groove (11) and the second permanent magnet groove (12) and the characteristic groove (101) at an adjacent position forms an isolation section (102).

2. The rotor punching according to claim 1, characterized in that: A characteristic groove (101) is provided at the radial outer end of the punch body (10) located on the Q axis, the depth of the characteristic groove (101) is L2, the width of the characteristic groove (101) along the radial direction of the punch body (10) is W2, and the distance between the outer groove wall of the characteristic groove (101) and the outer edge of the punch body (10) is H, wherein L2≤1mm, W2≤1.2mm, and 1mm≤H≤3mm.

3. The rotor punching according to claim 1, characterized in that: A first permanent magnet (20) is installed in the first permanent magnet slot (11), and a second permanent magnet (30) is installed in the second permanent magnet slot (12); when installed in place, an angle between the first permanent magnet (20) and the second permanent magnet (30) is 70°-120°.

4. The rotor punching according to claim 3, characterized in that: When installed in place, the angle between the first permanent magnet (20) and the second permanent magnet (30) is 90°.

5. The rotor punching according to claim 3, characterized in that: The length of the first permanent magnet (20) and the second permanent magnet (30) are both 14.4 mm, and the thickness is both 4 mm.

6. The rotor punching according to claim 1, characterized in that: The ends of the first permanent magnet slot (11) and the second permanent magnet slot (12) close to the outer edge of the punching sheet body (10) are respectively provided with a first air slot (13), and the punching sheet body (10) between the first air slot (13) and the outer edge of the punching sheet body (10) forms a first magnetic isolation bridge (131).

7. The rotor punching according to claim 1, characterized in that: A second air groove (14) is respectively provided at the end portions of the first permanent magnet groove (11) and the second permanent magnet groove (12) adjacent to each other, and the punching sheet body (10) between the second air groove (14) of the first permanent magnet groove (11) and the second air groove (14) of the second permanent magnet groove (12) forms a second magnetic isolation bridge (141).

8. The rotor punching according to claim 1, characterized in that: The first permanent magnet slot (11) and the second permanent magnet slot (12) are respectively provided with avoidance slots (15), and the avoidance slots (15) are arranged on the inner walls of the first permanent magnet slot (11) and the second permanent magnet slot (12) close to the outer side of the V-shape.

9. A rotor, characterized in that: The rotor has the rotor punching according to any one of claims 1 to 8.

10. A motor, characterized in that: The electric motor has the rotor according to claim 9.

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