Rotor punching, rotor core, rotor, motor

Abstract

The present invention provides a rotor punching, a rotor core, a rotor, and a motor. The rotor punching includes an annular ring with a central axis hole and a plurality of segment bodies evenly spaced around the outer side of the annular ring, a magnetic steel groove is formed between any two adjacent segment bodies, and any two adjacent segment bodies have grooves on the opposite radial side walls away from the annular ring, and the grooves extend in a direction perpendicular to the radial side walls. According to the rotor punching, rotor core, rotor, and motor of the present invention, by providing grooves on the radial side walls of the segment bodies, the cogging torque of the rotor can be reduced while the connection of the permanent magnet in the magnetic steel groove can be made more reliable.

Description

Technical Field

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

[0002] As a high-precision power output device, servo motors are widely used in robots, machine tools, packaging equipment, and printing equipment. As the rotor of the servo motor, radial rotors or surface-mount rotors are generally used. The surface-mount rotor is a rotor that sequentially adheres multiple permanent magnets to the outer surface of the cylindrical rotor core in the circumferential direction, while the radial rotor is a rotor that embeds multiple permanent magnets in the empty slots of the rotor core in the circumferential direction. Compared with surface-mount rotor servo motors, radial rotors have the advantages of reliable rotor structure and strong overload capacity, and are increasingly attracting attention from the industry. However, due to the structural characteristics of the punching sheets, radial rotors are more prone to magnetic leakage, which has an adverse effect on the performance of the motor. In addition, the stator and rotor of the servo motor will generate cogging torque under the action of the permanent magnet magnetic field, which will cause the output torque to fluctuate, directly affecting the accuracy of terminal equipment such as robots.

[0003] In the prior art, in order to reduce leakage magnetic flux, corresponding slots are constructed on the outer circumferential surface of the rotor core so that it can be connected with the permanent magnet slots, and corresponding protrusions are further provided at the slot openings to further reduce the leakage magnetic flux. However, the inventors found that the rotor tooth torque fluctuation is still large and the adverse effect on the rotor stiffness is also large. Based on this, the present invention is proposed. Summary of the invention

[0004] Therefore, the technical problem to be solved by the present invention is to provide a rotor punching, a rotor core, a rotor, and a motor. By setting grooves on the radial side walls of the segment body, the cogging torque of the rotor can be reduced while the connection of the permanent magnet in the magnetic steel slot can be made more reliable.

[0005] In order to solve the above problems, the present invention provides a rotor punching, comprising an annular ring with a central axis hole and a plurality of segment bodies evenly spaced around the outer side of the annular ring, a magnetic steel groove is formed between any two adjacent segment bodies, and any two adjacent segment bodies have grooves on the opposite radial side walls and away from the annular ring, and the grooves extend in a direction perpendicular to the radial side walls.

[0006] Preferably, the two grooves located on opposite sides of two adjacent segment bodies are symmetrical with respect to the radial symmetry plane of the magnetic steel slot.

[0007] Preferably, the groove has a radial inner groove wall close to the central shaft hole and a radial outer groove wall away from the central shaft hole, and the radial outer groove wall is an arc wall extending toward the central shaft hole.

[0008] Preferably, the groove also has a groove bottom wall, and a chamfered structure is provided between the radial outer groove wall and the groove bottom wall; and / or, a notch is also constructed on the radial side wall, and the notch is located on the radial outer side of the groove, and the notch extends in a direction perpendicular to the radial side wall and penetrates the radial outer side of the fan body.

[0009] Preferably, the two notches located on opposite sides of two adjacent segment bodies are symmetrical about the radial symmetry plane of the magnetic steel slot.

[0010] Preferably, the maximum circumferential spacing between the two notches on opposite sides of two adjacent segment bodies is L1, and the maximum circumferential spacing between the two grooves on opposite sides of two adjacent segment bodies is L2, and L2>L1.

[0011] Preferably, 0.75≤L1 / L2≤0.95.

[0012] Preferably, the minimum radial height of the notch is H1, the minimum radial height of the groove is H2, and H1<H2.

[0013] Preferably, 0.15≤H1 / H2≤0.3.

[0014] The present invention also provides a rotor core formed by stacking a plurality of rotor punchings, wherein the rotor punchings are the above-mentioned rotor punchings.

[0015] The present invention also provides a rotor, comprising the above-mentioned rotor core.

[0016] The present invention also provides a motor, comprising the above-mentioned rotor.

[0017] The present invention provides a rotor punching sheet, a rotor core, a rotor, and a motor. By means of a groove arranged on the radial side wall, a convex structure is objectively formed on the outer circumference of the sector body. This convex structure can effectively reduce the leakage magnetic amount and reduce the tooth torque, thereby helping to reduce torque fluctuations. At the same time, the arrangement of the groove can also serve as a part of the magnetic steel slot. The corresponding permanent magnet can be embedded in the magnetic steel slot having the groove, thereby forming radial support for the permanent magnet, thereby improving the connection reliability of the permanent magnet. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a schematic diagram of the structure of a rotor punching sheet according to an embodiment of the present invention (there are 10 magnetic steel slots in the figure);

[0019] Figure 2 for Figure 1 A partial enlarged view of the middle A;

[0020] Figure 3A schematic diagram of the structure of a permanent magnet used in conjunction with a rotor punching sheet according to an embodiment of the present invention;

[0021] Figure 4 is a schematic structural diagram of a rotor core according to an embodiment of the present invention;

[0022] Figure 5 is the corresponding curve between L1 / L2 and cogging torque of the present invention;

[0023] Figure 6 It is the corresponding curve between H1 / H2 and cogging torque of the present invention.

[0024] The reference numerals are as follows:

[0025] 11. Center axis hole; 12. Annular ring; 13. Sector body; 14. Magnetic steel groove; 15. Radial side wall; 16. Groove; 161. Arc wall; 17. Notch; 18. Permanent magnet. DETAILED DESCRIPTION

[0026] See also Figures 1 to 6 As shown, according to an embodiment of the present invention, a rotor punching is provided, comprising an annular ring 12 having a central axis hole 11 and a plurality of segments 13 evenly spaced around the outer side of the annular ring 12, a magnetic steel groove 14 is formed between any two adjacent segments 13, and a groove 16 is provided on the radial side walls 15 opposite to each other and away from the annular ring 12, and the groove 16 extends in a direction perpendicular to the radial side wall 15. In this technical solution, by providing the groove 16 on the radial side wall 15, a convex structure is objectively formed on the outer circumference of the segment body 13, and this convex structure can effectively reduce the magnetic leakage and the cogging torque, thereby facilitating the reduction of torque fluctuations. At the same time, the provision of the groove 16 can also serve as a part of the magnetic steel groove 14, and the corresponding permanent magnet 18 can be embedded in the magnetic steel groove 14 having the groove 16, thereby forming a radial support for the permanent magnet 18, thereby improving the connection reliability of the permanent magnet. The permanent magnet 18 is, for example, designed accordingly as Figure 3 The T-shaped structure shown.

[0027] The two grooves 16 on opposite sides of two adjacent segment bodies 13 are symmetrical about the radial symmetry plane of the magnetic steel groove 14, which can ensure the dimensional symmetry and consistency of the aforementioned objectively formed protruding structure, and further facilitate the reduction of the cogging torque.

[0028] Furthermore, the groove 16 has a radial inner groove wall close to the side of the central shaft hole 11 and a radial outer groove wall away from the side of the central shaft hole 11, and the radial outer groove wall is an arc wall 161 extending toward the side close to the central shaft hole 11. Preferably, the groove 16 also has a groove bottom wall, and a chamfered structure is provided between the radial outer groove wall and the groove bottom wall to enhance the structural strength of the raised structure, that is, to enhance the overall stiffness of the rotor punching and reduce its deformation after operation.

[0029] The radial side wall 15 is also provided with a notch 17, which is located radially outside the groove 16. The notch 17 extends in a direction perpendicular to the radial side wall 15 and penetrates the radial outside of the segment body 13. Preferably, the two notches 17 located on opposite sides of two adjacent segment bodies 13 are symmetrical about the radial symmetry plane of the magnetic steel slot 14. At this time, the notch 17 and the groove 16 together effectively reduce the cogging torque.

[0030] In the radial direction of the magnetic steel slot 14, the circumferential width of the magnetic steel slot 14 remains unchanged, that is, the two opposite radial side walls 15 are parallel to each other, so that Figure 2 L0=L5=L3, which is convenient for the manufacture and assembly of permanent magnets, ensures the best processing properties of permanent magnets and iron cores, reduces manufacturing costs and improves production efficiency.

[0031] Furthermore, in order to further improve the reduction of the cogging torque, the inventors conducted an experimental study on the maximum circumferential spacing between the two notches 17 on the opposite sides of the two adjacent blade bodies 13, which is L1, the maximum circumferential spacing between the two grooves 16 on the opposite sides of the two adjacent blade bodies 13, which is L2, the radial minimum height of the notch 17, which is H1, and the radial minimum height of the groove 16, which is H2. Specifically, Table 1 shows different detection results of the motor cogging torque under different L1 / L2 ratios. Figure 5 It can be seen intuitively that when L2>L1, 0.75≤L1 / L2≤0.95, the motor cogging torque is relatively small and the fluctuation is also small; Table 2 gives the different detection results of the motor cogging torque under different H1 / H2 ratios. Figure 6 It can be seen intuitively that when H1<H2, 0.15≤H1 / H2≤0.3, the motor cogging torque is relatively small and the fluctuation is also small.

[0032] Table 1 Effect of L1 / L2 on motor cogging torque

[0033] L1 / L2 Cogging torque / mN.m 0.5 19.43 0.55 17.21 0.6 12.69 0.65 10.16 0.7 9.65 0.75 8.73 0.8 7.72 0.85 8.09 0.9 7.67 0.95 8.35 1 9.26 1.05 10.39 1.1 13.18

[0034] Table 2 Effect of H1 / H2 on motor cogging torque

[0035] H1 / H2 Cogging torque / mN.m 0 22.17 0.05 18.26 0.1 16.37 0.15 11.38 0.2 9.26 0.25 9.38 0.3 10.68 0.35 13.79 0.4 15.38 0.45 16.87 0.5 16.69

[0036] In order to clarify the structural strength of the motor rotor within the above-mentioned L1 / L2 and H1 / H2 value ranges, the inventors tested and verified the maximum structural deformation of the motor rotor at the end points of the corresponding value ranges, as shown in Tables 3 and 4. The results in the tables show that when L1 / L2 is in the range of 0.75 to 0.95 and H1 / H2 is in the range of 0.15 to 0.3, the structural strength of the motor rotor meets the requirements.

[0037] Table 3 L1 / L2 strength check of motor rotor structure

[0038] L1 / L2 Maximum structural deformation / mm 0.75 0.003 0.95 0.007

[0039] Table 4 H1 / H2 strength check of motor rotor structure

[0040] H1 / H2 Maximum structural deformation / mm 0.15 0.005 0.3 0.008

[0041] According to an embodiment of the present invention, there is further provided a rotor core formed by stacking a plurality of rotor punchings, wherein the rotor punchings are the above-mentioned rotor punchings.

[0042] According to an embodiment of the present invention, a rotor is further provided, comprising the above-mentioned rotor core.

[0043] According to an embodiment of the present invention, a motor is also provided, which is composed of a stator, the above-mentioned rotor, a front end cover, a casing, a rear end cover, an encoder cover, an encoder, a front bearing and a rear bearing, wherein the stator is attached to the inner surface of the casing, the rotor is located on the inner side of the stator, the rotor and the stator are aligned in the axial direction, and there is a magnetic gap between the outer circular surface of the rotor and the inner circular surface of the stator in the radial direction. The rotor realizes rotational output through the front bearing and the rear bearing, and the front bearing is attached to the front end cover, and the rear bearing is attached to the rear end cover.

[0044] It is easy for those skilled in the art to understand that, under the premise of no conflict, the above-mentioned advantageous methods can be freely combined and superimposed.

[0045] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention shall be included in the protection scope of the present invention. The above are only preferred embodiments of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and variations can be made without departing from the technical principles of the present invention, and these improvements and variations should also be regarded as the protection scope of the present invention.

Claims

1. A rotor punching sheet, It is characterized in that The invention comprises an annular ring (12) having a central axis hole (11) and a plurality of segment bodies (13) uniformly spaced around the outer side of the annular ring (12); a magnetic steel groove (14) is formed between any two adjacent segment bodies (13); and a groove (16) is provided on the radial side walls (15) opposite to each other and away from the annular ring (12); the groove (16) extends in a direction perpendicular to the radial side walls (15); the groove (16) is a part of the magnetic steel groove (14); a permanent magnet (18) can be embedded in the magnetic steel groove (14) having the groove (16), thereby forming radial support for the permanent magnet (18); and the radial side walls A notch (17) is also constructed on (15), and the notch (17) is located on the radial outside of the groove (16). The notch (17) extends in a direction perpendicular to the radial side wall (15) and penetrates the radial outside of the segment body (13); the two notches (17) located on opposite sides of two adjacent segment bodies (13) are symmetrical about the radial symmetry plane of the magnetic steel groove (14); the maximum circumferential spacing between the two notches (17) located on opposite sides of two adjacent segment bodies (13) is L1, and the maximum circumferential spacing between the two grooves (16) located on opposite sides of two adjacent segment bodies (13) is L2, and 0.75≤L1 / L2≤0.

95.

2. The rotor punching according to claim 1, It is characterized in that The two grooves (16) located on opposite sides of two adjacent segment bodies (13) are symmetrical with respect to the radial symmetry plane of the magnetic steel slot (14).

3. The rotor punching according to claim 1, It is characterized in that The groove (16) comprises a radial inner groove wall on a side close to the central shaft hole (11) and a radial outer groove wall on a side away from the central shaft hole (11); the radial outer groove wall is an arc wall (161) extending towards the side close to the central shaft hole (11).

4. The rotor punching according to claim 3, It is characterized in that The groove (16) also has a groove bottom wall, and a rounded structure is provided between the radially outer groove wall and the groove bottom wall.

5. The rotor punching according to claim 1, It is characterized in that The minimum radial height of the notch (17) is H1, and the minimum radial height of the groove (16) is H2, where H1<H2.

6. The rotor punching according to claim 5, It is characterized in that 0.15≤H1 / H2≤0.

3.

7. A rotor core formed by laminating a plurality of rotor punchings. It is characterized in that The rotor punching is the rotor punching according to any one of claims 1 to 6.

8. A rotor comprising a rotor core, It is characterized in that The rotor core is the rotor core according to claim 7.

9. An electric machine comprising a rotor, It is characterized in that The rotor is the rotor according to claim 8.

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