A rotor structure of a pole-offset permanent magnet assisted synchronous motor

Abstract

The utility model relates to a kind of magnetic pole bias type permanent magnet auxiliary synchronous motor rotor structure, its structure includes rotating shaft, rotor core, pressing plate, permanent magnet and fastener, wherein the permanent magnet slot is equipped on rotor core, permanent magnet slot is inlayed with permanent magnet, the installation position of permanent magnet is offset 5 ° electric angle relative to rotor magnetic pole center line.The utility model has the advantages of: reasonable structure design, permanent magnet is inlayed into rotor core using bias mode, i. e. permanent magnet center line and magnetic pole center line are staggered a bias angle, thereby optimizing air gap magnetic field, significantly reduce torque ripple, overall structural strength is high, process is good, operation is stable, suitable for the high-end synchronous motor of harsh performance and quality requirement.

Description

Technical Field

[0001] This utility model relates to a rotor structure of an electric motor, specifically to a rotor structure of a magnetic pole bias type permanent magnet assisted synchronous motor. Background Technology

[0002] Synchronous motors are widely used in industrial drives and new energy power generation due to their advantages such as high power factor, high operating efficiency, and stable speed. Permanent magnet assisted synchronous motors further improve the power density and efficiency of the motor by embedding permanent magnets in the rotor.

[0003] In existing technologies, the rotor structure of permanent magnet assisted synchronous motors mostly adopts an integral iron core, with permanent magnets typically arranged symmetrically at the center of the magnetic poles. This structure has some inherent drawbacks: First, the sinusoidal nature of the air gap magnetic field is poor, resulting in large torque pulsation, causing vibration and noise; second, when the integral iron core rotates at high speed, centrifugal force may cause deformation at the ends of the iron core, affecting operational reliability; finally, the assembly process, especially the installation and fixing of the permanent magnets, is complex and poses safety hazards. Utility Model Content

[0004] This utility model proposes a rotor structure for a permanent magnet assisted synchronous motor with magnetic pole bias, which aims to overcome the above-mentioned shortcomings of the existing technology, optimize the magnetic field distribution, reduce torque pulsation, enhance mechanical strength, and simplify the manufacturing process.

[0005] The technical solution of this utility model is a rotor structure for a permanent magnet assisted synchronous motor with magnetic pole bias. The structure includes a shaft, a rotor core, a pressure plate, permanent magnets, and fasteners. The rotor core has slots for permanent magnets, and permanent magnets are embedded in these slots. The permanent magnets are positioned with their installation positions offset by 5° electrical angle relative to the rotor's magnetic pole centerline. This magnetic pole bias design effectively improves the sinusoidal nature of the air gap magnetic field, significantly reduces torque pulsation in the motor, thereby reducing vibration and noise and improving operational quality.

[0006] Preferably, the rotor core consists of a first core segment and a second core segment of equal length, which are adjacently fitted onto the rotating shaft. Both the first and second core segments have permanent magnet slots, and permanent magnets are respectively embedded in these slots. The installation positions of the permanent magnets in the first and second core segments are offset by 5° electrical angle relative to the rotor magnetic pole centerline. The segmented core facilitates the embedding and fixing of permanent magnets, simplifies the assembly process, and reduces the risk associated with permanent magnet installation.

[0007] Preferably, the first and second iron core sections are circumferentially positioned with the rotating shaft by a flat key, which is installed in a keyway on the edge of the rotating shaft. Flat key positioning ensures assembly accuracy.

[0008] Preferably, pressure plates are respectively provided on the outer shafts of the first and second iron core sections, and the pressure plates on both sides are axially pressed and fixed by a fastener. The segmented iron core structure, combined with the pressure plates at both ends, can enhance the overall axial stiffness and resistance to centrifugal deformation of the rotor, making it particularly suitable for high-speed operation.

[0009] The advantages of this utility model are: reasonable structural design, permanent magnets are embedded in the rotor core in an offset manner, that is, the center line of the permanent magnet is offset from the center line of the magnetic pole by an offset angle, thereby optimizing the air gap magnetic field, significantly reducing torque pulsation, high overall structural strength, good manufacturability, and stable operation, which is suitable for high-end synchronous motors with stringent performance and quality requirements. Attached Figure Description

[0010] Figure 1 This is a schematic diagram of the rotor structure of the magnetic pole bias type permanent magnet assisted synchronous motor of this utility model.

[0011] Figure 2 yes Figure 1 A sectional view along the AA direction.

[0012] Figure 3 yes Figure 1 BB-direction sectional view.

[0013] In the diagram, 1 is the shaft, 21 is the first section of the iron core, 22 is the second section of the iron core, 3 is the pressure plate, 4 is the flat key, 5 is the permanent magnet, and 6 is the fastener. Detailed Implementation

[0014] The present invention will be further described in detail below with reference to embodiments and specific implementation methods.

[0015] like Figure 1-3 As shown, a rotor structure of a permanent magnet assisted synchronous motor with magnetic pole bias is disclosed. The structure includes a rotating shaft 1, a rotor core, a pressure plate 3, permanent magnets 5, and fasteners 6. The rotor core consists of a first core segment 21 and a second core segment 22 of equal length. The first core segment 21 and the second core segment 22 are adjacently sleeved on the rotating shaft 1. The first core segment 21 and the second core segment 22 are circumferentially positioned with the rotating shaft 1 by a flat key 4. The flat key 4 is installed in a keyway on the edge of the rotating shaft 1. Pressure plates 3 are respectively provided on the rotating shaft 1 outside the first core segment 21 and the second core segment 22. The two pressure plates 3 are axially pressed and fixed by a fastener 6. Both the first core segment 21 and the second core segment 22 are provided with permanent magnet slots. Permanent magnets 5 are embedded in the permanent magnet slots of the first core segment 21 and the second core segment 22. The installation position of the permanent magnets 5 in the first core segment 21 and the second core segment 22 is offset by 5° electrical angle relative to the center line of the rotor magnetic pole.

[0016] During assembly, firstly, the two flat keys 4 are installed into the keyways on both sides of the rotating shaft 1; then, the first iron core 21 (the rotor laminations are stacked from the front to a length L=55mm) and the second iron core 22 (the rotor laminations are stacked from the back to a length L=55mm) are sequentially fitted onto the rotating shaft 1, and circumferentially positioned using the flat keys 4; after the pressure plates 3 at both ends are placed in place, axial pressure is applied using fasteners 6 (in one embodiment, a screw passes through the holes on the rotating shaft 1 and the pressure plate 3, and both ends are tightened with nuts) to firmly press the entire rotor core onto the rotating shaft 1; the permanent magnet 5 is embedded in the pre-designed permanent magnet slot during or after the iron core stacking process. The installation position of the permanent magnet 5 is offset from the rotor magnetic pole centerline by an angle α (5° electrical angle), which is the core of optimizing electromagnetic performance. After all assembly is completed, the rotor is dynamically balanced to remove imbalance until the balance level requirements of ISO 1940 G2.5 are met; finally, the rotor surface is cleaned.

[0017] The above structural design has the following characteristics: Low torque pulsation and high operational stability: Through the magnetic pole bias design, the sinusoidal nature of the air gap magnetic field can be effectively improved, significantly reducing the torque pulsation of the motor, thereby reducing vibration and noise and improving operational quality.

[0018] High mechanical strength and reliability: The segmented core structure, combined with the pressure plates at both ends, enhances the overall axial stiffness and resistance to centrifugal deformation of the rotor, making it particularly suitable for high-speed operation.

[0019] Excellent processability and safety: The segmented iron core facilitates the embedding and fixing of permanent magnets, simplifies the assembly process, and reduces the risk of permanent magnet installation. Flat key positioning ensures assembly accuracy.

[0020] All of the components described above are existing technologies, and those skilled in the art can use any model and existing design that can achieve their corresponding functions.

[0021] The above description is only a preferred embodiment of the present utility model. It should be noted that for those skilled in the art, several modifications and improvements can be made without departing from the inventive concept of the present utility model, and these all fall within the protection scope of the present utility model.

Claims

1. A rotor structure for a permanent magnet assisted synchronous motor with magnetic pole bias, characterized in that, It includes a rotating shaft (1), a rotor core, a pressure plate (3), a permanent magnet (5) and fasteners (6), wherein the rotor core is provided with a permanent magnet slot, and a permanent magnet (5) is embedded in the permanent magnet slot. The installation position of the permanent magnet (5) is offset by 5° electrical angle relative to the center line of the rotor magnetic pole.

2. The rotor structure of a permanent magnet assisted synchronous motor with magnetic pole bias as described in claim 1, characterized in that, The rotor core consists of a first core (21) and a second core (22) of equal length. The first core (21) and the second core (22) are fitted together on the rotating shaft (1). The first core (21) and the second core (22) are provided with permanent magnet slots. The permanent magnets (5) are respectively embedded in the permanent magnet slots of the first core (21) and the second core (22). The installation position of the permanent magnets (5) in the first core (21) and the second core (22) is offset by 5° electrical angle relative to the center line of the rotor magnetic pole.

3. The rotor structure of a permanent magnet assisted synchronous motor with magnetic pole bias as described in claim 2, characterized in that, The first section of iron core (21) and the second section of iron core (22) are circumferentially positioned with the rotating shaft (1) by a flat key (4), and the flat key (4) is installed in the keyway on the edge of the rotating shaft (1).

4. The rotor structure of a permanent magnet assisted synchronous motor with magnetic pole bias as described in claim 2, characterized in that, Pressure plates (3) are respectively provided on the rotating shaft (1) on the outer side of the first section of iron core (21) and the second section of iron core (22), and the pressure plates (3) on both sides are axially pressed and fixed by a fastener (6).

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