Stator and rotor iron core for permanent magnet synchronous motor and motor

Abstract

The invention discloses a stator and rotor iron core for a permanent magnet synchronous motor and a motor, and relates to the technical field of permanent magnet synchronous motors. The rotor is a three-section type rotor, the whole rotor is conical, the outer diameter of the rotor is sequentially decreased from large to small, rotor magnetic steel grooves are V-shaped magnetic steel grooves, the angle of each section of rotor groove is 100 degrees, 115 degrees and 130 degrees, the harmonic magnetic field content of the rotor can be improved, noise can be reduced, the power density is improved under the same size, the rotor can move leftwards and rightwards, and the rotor moves towards the direction, with the smaller inner diameter, of the stator. And the set of stator and rotor can be used in places with high safety degree. The invention has the advantages of high motor torque density, high slot space factor, reduced cogging torque, reduced torque pulsation, reduced harmonic magnetic field content and low noise.

Description

Technical Field

[0001] This invention relates to the field of permanent magnet synchronous motor technology, specifically to a stator and rotor core and a motor for a permanent magnet synchronous motor. Background Technology

[0002] As a modern high-performance servo motor and high-torque direct drive motor, the permanent magnet synchronous motor has the characteristics of high peak torque, strong overload capacity, small torque fluctuation, large torque / weight ratio, high efficiency, high power factor, smooth low-speed operation, low vibration, low noise, short axial dimension, compact structure, and can be made into a multi-air gap combined structure to further improve torque. It has broad application prospects in power systems such as CNC machine tools, robots, flywheel energy storage systems, high-speed centrifuges, electric vehicles, all-electric ships, and underwater vehicles.

[0003] Existing technologies mainly limit the output of motor power and torque through a rotor magnet topology, and also make it difficult for the motor to obtain the optimal sinusoidal back EMF waveform. This technology greatly improves the output of the motor's ultimate power density and torque density through the optimization of several magnet topologies. Summary of the Invention

[0004] The purpose of this invention is to provide a stator and rotor core for a permanent magnet synchronous motor and the motor itself, thereby solving the above-mentioned technical problems.

[0005] The objective of this invention can be achieved through the following technical solutions: A stator and rotor core for a permanent magnet synchronous motor includes a stator and a rotor that cooperate with each other. Both the stator and the rotor are conical structures. The rotor can move axially within the stator and achieves self-locking when it moves towards the side with the smaller inner diameter of the stator.

[0006] As a further aspect of the present invention: the rotor is composed of multiple rotor laminations spliced ​​together, and when the stator and rotor are in a clearance fit state, the air gap between them remains consistent.

[0007] As a further aspect of the present invention: the rotor includes a first rotor lamination, a second rotor lamination, and a third rotor lamination arranged axially and having successively decreasing outer diameters.

[0008] As a further aspect of the present invention: the length of the first rotor lamination is L1, the length of the second rotor lamination is L2, the length of the third rotor lamination is L3, and the total length of the rotor is L0, satisfying L0=(L1+L2+L3) / (2*{tan[g*(π / 4)]},g is the air gap length.

[0009] As a further aspect of the present invention: the magnet slots of the first rotor lamination, the second rotor lamination, and the third rotor lamination are all V-shaped.

[0010] As a further aspect of the present invention: the magnet slot of the first rotor lamination has a length of L4 and a width of h1, the magnet slot of the second rotor lamination has a length of L5 and a width of h2, and the magnet slot of the third rotor lamination has a length of L6 and a width of h3, satisfying L4*h1. <L5*h2<L6*h3。

[0011] As a further aspect of the present invention: the included angle of the magnet slots of the first rotor lamination is 100°-105°, the included angle of the magnet slots of the second rotor lamination is 115°-120°, and the included angle of the magnet slots of the third rotor lamination is 130°-135°.

[0012] As a further aspect of the present invention: the stator surface array has multiple winding slots, and flat wire windings are embedded in the winding slots.

[0013] As a further aspect of the present invention: a permanent magnet synchronous motor is obtained by pressing a rotor into the stator.

[0014] As a further aspect of the present invention, the rotor is installed by pressing the first rotor lamination, the second rotor lamination, and the third rotor lamination sequentially onto the rotating shaft.

[0015] The beneficial effects of this invention are: The stator core of this invention has an overall conical shape, which can reduce the amount of copper and iron used. Flat wire windings are embedded in the stator winding slots, which can improve motor efficiency and torque density. The rotor is a three-section rotor with an overall conical shape and the outer diameter decreasing from large to small. The rotor magnet slots are V-shaped magnet slots, and the angles of each rotor slot are 100°, 115°, and 130°. The three laminations cooperate with each other, so that the rotor harmonic magnetic field content is adjusted accordingly. Through the optimized angle design, the non-sinusoidal degree of the original air gap magnetic field is changed, thereby reducing noise. To increase power density within the same volume, because the rotor diameter is larger at one end and smaller at the other, when the stator remains stationary, the rotor will collide with the stator as it moves from the smaller diameter to the larger diameter, thus restricting its movement and stopping the machine. This stator and rotor system can be used in applications requiring high safety standards. Attached Figure Description

[0016] The invention will now be further described with reference to the accompanying drawings.

[0017] Figure 1 This is a schematic diagram of the overall structure of the present invention; Figure 2 This is a cross-sectional schematic diagram of the overall structure of the present invention; Figure 3 This is a cross-sectional planar structural schematic diagram of the present invention; Figure 4This is a partial planar structural schematic diagram of the present invention in cross-section; Figure 5 This is a front view of the rotor core and stator core of the magnetic steel slots of the present invention with an included angle of 100°; Figure 6 This is a front view of the rotor core and stator core of the magnetic steel slots of the present invention with an included angle of 115°; Figure 7 This is a front view of the rotor core and stator core of the magnetic steel slots of the present invention with an included angle of 130°; Figure 8 This is a front view of the rotor core of the present invention with an included angle of 100°; Figure 9 This is a front view of the rotor core of the present invention with an included angle of 115°; Figure 10 This is a front view of the rotor core of the present invention with an included angle of 130°; Figure 11 This is the curve showing the effect of current on power density in this invention and prior art. Figure 12 This is the curve showing the effect of current on torque density in this invention and in the prior art. Detailed Implementation

[0018] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0019] This invention provides a high-performance, low-noise permanent magnet synchronous motor, mainly used in applications requiring high safety. This permanent magnet synchronous motor has the following advantages: high motor torque density, high slot fill factor, reduced cogging torque, reduced torque pulsation, reduced harmonic magnetic field content, and low noise.

[0020] Please see Figure 1 As shown, the permanent magnet synchronous motor includes a stator 1 and a rotor 2, both of which are designed with a conical structure and fit together. During assembly, the stator 1 and rotor 2 are first pressed together, and then flat wire windings are embedded in the pear-shaped slots of the stator. This process sequence simplifies the manufacturing process, helps reduce costs, and improves production flexibility and the reliability of the final product. The rotor 2 can move axially within the stator 1. When the rotor 2 moves toward the side with the smaller inner diameter of the stator 1, the wedge-tightening effect of the tapered mating surface can achieve self-locking, enhancing the stability of the motor under specific operating conditions.

[0021] The stator 1 is formed by axially laminating multiple electrical steel stator punchings. On its inner circumferential surface, a plurality of pear-shaped slots are arrayed, and these slots are used to embed coil windings composed of flat copper wires. The use of flat wire windings can increase the slot fill factor, thereby improving the power density and efficiency of the motor.

[0022] The rotor 2 adopts a segmented splicing design. By optimizing the angular relationship, the sinusoidality of the back electromotive force waveform is improved, thereby improving the cogging torque. The torque density of the motor is increased through the different magnetic steel angular relationships; the aim is to optimize the air gap magnetic field waveform, improve the sinusoidality of the back electromotive force, reduce the cogging torque, and increase the torque density. In this embodiment, the rotor 2 is composed of three segments of rotor punchings axially spliced together.

[0023] Please refer to Figure 2 As shown, it is segmented: The rotor 2 specifically includes a first rotor punching 21, a second rotor punching 22, and a third rotor punching 23 that are arranged axially and have gradually decreasing outer diameters. Each segment of the rotor punching itself is also formed by laminating multiple rotor punchings. During assembly, the first, second, and third rotor punchings are sequentially pressed onto the rotating shaft in order. When the stator 1 and the rotor 2 are in the designed clearance fit state, the air gap at each point along the axis remains uniform.

[0024] Magnet slots are provided on all three segments of the rotor punchings, and the magnet slots all adopt a V-shaped layout.

[0025] Please refer to Figure 3-10 As shown, the dimensional parameters of the magnet slots in each segment satisfy the relationship: L4*h1 < L5*h2 < L6*h3 (where L4, L5, and L6 are the slot lengths, and h1, h2, and h3 are the slot widths). Through this stepped design of the area, the back electromotive force waveform with the best sinusoidality can be obtained, effectively improving the NVH (noise, vibration, and harshness) performance of the motor.

[0026] The V-shaped angles of the magnet slots in each segment are optimized, and they are respectively: 100° for the first rotor punching 21, 115° for the second rotor punching 22, and 130° for the third rotor punching 23. The different angle combinations help to further optimize the magnetic field distribution.

[0027] Length relationship: Let the lengths of the first, second, and third rotor punchings be L1, L2, and L3 respectively, the total effective length of the rotor be L0, and the air gap length be g. They satisfy the following relationship: L0 = (L1 + L2 + L3) / (2 * {tan[g * (π / 4)]}) This relationship shows that the total rotor length L0 is adjusted according to the change of the air gap g. Such a design can obtain the best air gap magnetic field distribution and at the same time help to improve the power density of the motor.

[0028] The following tests were conducted on the power density (kW / kg) and torque density (Nm / kg) of the permanent magnet synchronous motor in this embodiment and a conventional permanent magnet synchronous motor (whose stator contains only a cylindrical rotor) under different currents (10A-100A). The test results are shown in Tables 1 and 2 below: Table 1 Current / A Power density (kW / kg) of this application Power density of existing technology (kW / kg) 10 0.833 0.633 20 1.525 1.211 30 2.261 1.788 40 2.911 2.414 50 3.527 3.009 60 4.049 3.411 70 4.559 3.645 80 4.827 3.812 90 4.963 3.939 100 5.032 4.006 Table 2 Current / A Torque density (Nm / Kg) of this application Torque density of existing technology (Nm / Kg) 10 1.557 0.623 20 2.241 1.209 30 2.851 1.799 40 3.368 2.428 50 4.045 3.012 60 4.682 3.424 70 5.239 3.657 80 5.686 3.817 90 5.933 3.939 100 6.08 4.011 As shown in the table above, the curves illustrating the effect of specific current on power density are as follows: Figure 11 As shown in the figure, the curve of the effect of current on torque density is as follows: Figure 12 As shown in the figure; it is clear from the above data that the segmented conical rotor structure motor provided in this embodiment shows a significant improvement in both density indicators.

[0029] Therefore, this embodiment achieves a permanent magnet synchronous motor with simple process, low cost, high power density, high torque density and excellent NVH performance through stator and rotor conical fit and self-locking design, stator flat wire winding, and core three-segment variable parameter V-type magnet rotor splicing technology.

[0030] The foregoing has provided a detailed description of one embodiment of the present invention, but this description is merely a preferred embodiment and should not be construed as limiting the scope of the invention. All equivalent variations and modifications made within the scope of the claims of this invention should still fall within the patent coverage of this invention.

Claims

1. A stator and rotor core for a permanent magnet synchronous motor, comprising a stator (1) and a rotor (2) that cooperate with each other, characterized in that, Both the stator (1) and the rotor (2) are conical structures. The rotor (2) can move axially within the stator (1). When it moves towards the side with the smaller inner diameter of the stator (1), it completes self-locking.

2. The stator and rotor core for a permanent magnet synchronous motor according to claim 1, characterized in that, The rotor (2) is made up of multiple rotor laminations spliced ​​together, and when the stator (1) and the rotor (2) are in a clearance fit state, the air gap between them remains consistent.

3. The stator and rotor core for a permanent magnet synchronous motor according to claim 1, characterized in that, The rotor (2) includes a first rotor lamination (21), a second rotor lamination (22), and a third rotor lamination (23) arranged along the axial direction with decreasing outer diameters.

4. The stator and rotor core for a permanent magnet synchronous motor according to claim 3, characterized in that, The length of the first rotor lamination (21) is L1, the length of the second rotor lamination (22) is L2, the length of the third rotor lamination (23) is L3, and the total length of the rotor (2) is L0, satisfying L0=(L1+L2+L3) / (2*{tan[g*(π / 4)]}), where g is the air gap length.

5. A stator and rotor core for a permanent magnet synchronous motor according to claim 3 or 4, characterized in that, The magnet slots of the first rotor lamination (21), the second rotor lamination (22), and the third rotor lamination (23) are all V-shaped.

6. The stator and rotor core for a permanent magnet synchronous motor according to claim 5, characterized in that, The first rotor lamination (21) has a magnet slot with a length of L4 and a width of h1, the second rotor lamination (22) has a magnet slot with a length of L5 and a width of h2, and the third rotor lamination (23) has a magnet slot with a length of L6 and a width of h3, satisfying L4*h1. <L5*h2<L6*h3。 7. The stator and rotor core for a permanent magnet synchronous motor according to claim 6, characterized in that, The included angle of the magnet slots of the first rotor lamination (21) is 100°-105°, the included angle of the magnet slots of the second rotor lamination (22) is 115°-120°, and the included angle of the magnet slots of the third rotor lamination (23) is 130°-135°.

8. The stator and rotor core for a permanent magnet synchronous motor according to claim 1, characterized in that, The stator (1) has multiple winding slots on its surface array, and flat wire windings are embedded in the winding slots.

9. A permanent magnet synchronous motor, characterized in that, The rotor (2) is obtained by pressing the stator (1) into the stator (1) using the stator and rotor core as described in any one of claims 1-8.

10. A permanent magnet synchronous motor according to claim 9, characterized in that, The rotor (2) is installed by pressing the first rotor lamination (21), the second rotor lamination (22) and the third rotor lamination (23) onto the shaft in sequence.

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