Rotor structure of permanent magnet motor

Abstract

The utility model provides a rotor structure of a permanent magnet motor, which comprises a stator and a rotor, the stator is positioned on the outer side, coils are wound on the stator and are tied in a specific mode, an air gap is arranged between the stator and the rotor, the space between the stator and the rotor is not fixed, the rotor is in a non-perfect circle design, the rotor is provided with a plurality of V-shaped grooves, two magnets are arranged in each V-shaped groove, and the V-shaped grooves are provided with stop blocks. The magnet in the groove is fixed under the limitation of the stop block; a plurality of magnetic field guiding grooves are formed in the outer edge contour of the rotor, each V-shaped groove corresponds to two magnetic field guiding grooves, and the magnetic field guiding grooves are located on the two sides of the V-shaped grooves and are symmetrically distributed; the V-shaped groove serves as a boundary and divides the rotor into two areas, the interior of a V-shaped included angle is called as a V-shaped upper half area, the exterior of the V-shaped included angle is called as a V-shaped lower half area, and the first rectangular holes are located in the middle line of the V-shaped groove of the V-shaped upper half area; the plurality of second rectangular holes are located at the center line between the two V-shaped grooves, and the circular hole is located at the center line of the V-shaped groove of the V-shaped lower half area.

Description

TECHNICAL FIELD

[0001] The utility model relates to a kind of rotor magnetic field guide grooves, to achieve low cogging torque, maximum torque and high-speed torque is equivalent, lightweight and many characteristics, especially conducive to the application in the speed widely motor car motor permanent magnet motor rotor structure. BACKGROUND

[0002] Cogging torque refers to the torque generated between the rotor magnet and the stator tooth in a permanent magnet motor. This torque occurs when there is no current in the stator and varies periodically with the change in rotor position. In simple terms, cogging torque is a magnetic resistance force caused by the internal magnetic field distribution of the motor. This torque affects the smooth operation of the motor, especially at low speeds, which can cause vibration and noise during motor operation.

[0003] Please refer to Figure 1 (TWI617115B in China Taiwan) and Figure 2 (TW202318756A in China Taiwan), the prior art reduces cogging torque by auxiliary holes on both sides and a middle hole. However, the auxiliary holes on both sides can suppress the leakage of magnet flux to some extent, but there are still two leakage paths in the flow guide area. In addition, the middle hole blocks the main flux path. Considering the above two factors, the prior art greatly sacrifices the average torque to obtain low cogging torque.

[0004] The prior art reduces cogging torque by modifying the stator shoe, the rotor, the rotor slot, and the rotor guide hole. These methods can reduce the average torque of the motor by 5-10%. The above-mentioned methods for reducing cogging torque by modifying the stator shoe, the rotor, and the rotor slot are not easy to make the motor lightweight.

[0005] In addition, Figure 1 (TWI617115B in China Taiwan) and Figure 2 (TW202318756A in China Taiwan), the auxiliary holes and the middle hole are affected by centrifugal force at high speed, which requires the width of the two leakage paths in the flow guide area to be controlled within a certain size, thereby limiting the size of the hole diameter. This design has many limitations and needs to be improved.

[0006] Considering the above reasons, the prior art still has room for improvement. The inventor has actively researched and accumulated experience in related product development for many years. After continuous testing and improvement, the utility model has been developed. UTILITY MODEL CONTENT

[0007] The main objective of this invention is to provide a rotor structure for a permanent magnet motor that utilizes a magnetic field guiding groove in the rotor to achieve low torque at low speeds, maximum torque comparable to high-speed torque, and lightweight design. This is particularly advantageous for applications in electric locomotives with a wide range of speed controls.

[0008] The secondary objective of this invention is to provide a rotor structure for a permanent magnet motor. This invention is a magnetic field guiding groove. Due to the geometric characteristics of the guiding groove, the magnetic flux leakage path in the guiding area is reduced to one, and the design without intermediate holes is more advantageous than the conventional technology that sacrifices more average torque in exchange for lower torque at the moment of impact.

[0009] Another objective of this invention is to provide a rotor structure for a permanent magnet motor. Due to the geometric characteristics of the guide groove, this invention only needs to control the width of the single magnetic flux leakage path in the guide area, which allows for more design flexibility.

[0010] To achieve the above objectives, this utility model provides a rotor structure for a permanent magnet motor, characterized in that it includes:

[0011] A stator, located on the outside, has a ring structure, and the stator is wound with coils and wired in a specific manner;

[0012] A rotor, with a circular cylindrical structure, is designed to be non-circular. An air gap exists between the stator and the rotor, and the spacing of this air gap is not fixed. The rotor has a plurality of V-grooves, each containing a magnet. A stop block is provided in each V-groove to fix the magnet within the groove. A magnetic field guiding groove is provided on the outer edge of the rotor, with each V-groove corresponding to one of the magnetic field guiding grooves. The magnetic field guiding groove is located on both sides of the V-grooves and is symmetrically distributed.

[0013] Each V-groove serves as a dividing point, dividing the rotor into two regions: the area inside the V-angle is called the upper V-region, and the area outside the V-angle is called the lower V-region. A plurality of first rectangular holes are located on the center line of the V-groove in the upper V-region; a plurality of second rectangular holes are located at the center line between two of the plurality of V-grooves; and a circular hole is located at the center line of the V-groove in the lower V-region.

[0014] Two magnets are placed in each of the V-shaped grooves.

[0015] The outer edge of the rotor has multiple magnetic field guiding grooves, and each V-shaped groove corresponds to two magnetic field guiding grooves.

[0016] The advantages of this invention are as follows: The V-shaped groove serves as a dividing line, dividing the rotor into two regions. The area inside the V-angle is called the upper V-shaped region, and the area outside the V-angle is called the lower V-shaped region. A plurality of first rectangular holes are located on the center line of the V-shaped groove in the upper V-shaped region. Besides serving as a riveting and joining tool, they also suppress magnetic flux leakage. A plurality of second rectangular holes are located at the center line between the two V-shaped grooves, serving not only as a riveting and joining tool but also as a magnetic field guide. Circular holes are located at the center line of the V-shaped groove in the lower V-shaped region, their function being to suppress magnetic flux leakage and reduce weight.

[0017] To further understand the features and technical content of this utility model, please refer to the following detailed description and drawings. However, the drawings are for reference and illustration only and are not intended to limit this utility model in any way. Attached Figure Description

[0018] Figure 1 A plan view showing the application of the rotor structure of the known Taiwan Patent No. TWI617115B;

[0019] Figure 2 A plan view illustrating the application of a rotor structure known in Taiwan Patent No. TW202318756A;

[0020] Figure 3 This is a plan view of the rotor structure of the permanent magnet motor of this utility model;

[0021] Figure 4 This is a plan view showing the application of the rotor structure of the permanent magnet motor of this utility model;

[0022] Figure 5 for Figure 4 A magnified view of a portion of the document;

[0023] Figure 6 This is a data line diagram of the operating points of the rotor structure of the permanent magnet motor of this utility model;

[0024] Figure 7 This is a diagram showing the torque data of the rotor structure of the permanent magnet motor of this invention.

[0025] Explanation of reference numerals in the attached drawings: 10-stator; 15-air gap; 20-rotor; 22-V-groove; 24-magnet; 26-magnetic field guiding groove; 28-first rectangular hole; 30-second rectangular hole; 32-circular hole; 34-stop block. Detailed Implementation

[0026] Please see Figures 3 to 5As shown, this utility model provides a rotor structure for a permanent magnet motor. The structure includes a stator 10 and a rotor 20. The stator is located on the outer side, and coils are wound around the stator and wired in a specific manner. An air gap 15 exists between the stator 10 and the rotor 20, and the spacing between them is not fixed. The non-circular design of the rotor 20 allows for a gradual increase or decrease in magnetic reluctance, thereby reducing sudden torque. The rotor 20 has multiple V-grooves 22, each containing two magnets 24. Stops 34 on the V-grooves 22 fix the magnets 24 within the grooves. Multiple magnetic field guiding grooves 26 are located on the outer edge of the rotor 20, with each V-groove 22 corresponding to two magnetic field guiding grooves 26. The magnetic field guiding grooves 26 are symmetrically distributed on both sides of the V-groove 22. The V-groove 22 serves as a dividing line, dividing the rotor 20 into two regions: the area inside the V-angle is called the upper V-region, and the area outside the V-angle is called the lower V-region. A plurality of first rectangular holes 28 are located on the centerline of the V-groove 22 in the upper V-region. Besides serving as a riveting and mating joint, they also suppress magnetic flux leakage. A plurality of second rectangular holes 30 are located at the centerline between the two V-grooves 22, serving not only as a riveting and mating joint but also as guiding the magnetic field. Circular holes 32 are located at the centerline of the V-groove 22 in the lower V-region, their function being to suppress magnetic flux leakage and reduce weight.

[0027] The rotor structure of this utility model permanent magnet motor utilizes the magnetic field guiding groove 26 of the rotor 20 to achieve low torque at low speeds, maximum torque comparable to high-speed torque, and lightweight design; it is particularly advantageous for use in electric locomotive motors with wide speed regulation.

[0028] The rotor structure of the permanent magnet motor of this utility model is a magnetic field guiding groove 26. Due to the geometric characteristics of the magnetic field guiding groove 26, the magnetic flux leakage path in the guiding area is reduced to one, and the design without intermediate holes is more advantageous than the conventional technology that sacrifices more average torque in exchange for lower jerking torque.

[0029] Because of the geometric characteristics of the magnetic field guiding groove 26, the rotor structure of the permanent magnet motor of this utility model only needs to control the width of the single magnetic flux leakage path in the guiding area, which allows for more design flexibility.

[0030] There is a first rectangular hole 28 above the center line of the V-groove 22, and a second rectangular hole 30 is located between the V-groove 22. The feature of these holes is to suppress the leakage of magnetic flux from the bottom magnet. When the product is positioned for high-priced / high-performance applications, self-adhesive silicon steel sheets are used to form the core by pressurization and heating, thereby increasing the product performance. In this case, the main functions of the first rectangular hole 28 and the second rectangular hole 30 are to suppress magnetic flux leakage and reduce rotor weight.

[0031] When the product is positioned as affordable / general application, the core is made by riveting ordinary silicon steel sheets. In this case, the first rectangular hole 28 and the second rectangular hole 30 are used as the riveting joint of the silicon steel sheets, which can also reduce magnetic flux leakage to a certain extent.

[0032] The minimum distance between the first rectangular hole 28 and the V-groove 22 is related to the maximum operating speed of the motor. Generally, the minimum distance is 1 times the thickness of the silicon steel sheet.

[0033] Below the centerline of the V-groove 22 is a circular hole 32. Its features include suppressing the leakage of magnetic flux from the bottom magnet and reducing weight, as well as effectively blocking the leakage of magnetic flux to the shaft center, reducing the risk of interference to the shaft end position sensor, thereby avoiding the impact on motor performance.

[0034] Please continue reading. Figure 6 and Figure 7 As shown, it is a graph of its operating point data and a graph of its sudden torque data; in Figure 6 In the medium and low-speed operating points, the average torque decreased slightly (↓1.2%) after adding the magnetic field guide groove; while the average torque at the high-speed operating points increased slightly (↑1.0%) after adding the magnetic field guide groove; furthermore... Figure 7 The peak torque of the sudden turn decreased significantly by 54% after the magnetic field guiding groove was added. Under the condition of equivalent torque (about ±1%), the sudden turn performance was significantly improved.

[0035] Although the present invention has been disclosed above by the preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art should be able to make some modifications and refinements without departing from the spirit and scope of the present invention, and all such modifications and refinements shall fall within the protection scope of the present invention.

Claims

1. A rotor structure for a permanent magnet motor, characterized in that, include: A stator, located on the outside, has a ring structure, and the stator is wound with coils and wired in a specific manner; A rotor, with a circular cylindrical structure, is designed to be non-circular. An air gap exists between the stator and the rotor, and the spacing of this air gap is not fixed. The rotor has multiple V-grooves, each containing a magnet. A stop block is provided in each V-groove to fix the magnet within the groove. A magnetic field guiding groove is provided on the outer edge of the rotor, with each V-groove corresponding to one of the magnetic field guiding grooves. The magnetic field guiding groove is located on both sides of the multiple V-grooves and is symmetrically distributed. Each V-groove serves as a dividing point, dividing the rotor into two regions: the area inside the V-angle is called the upper V-region, and the area outside the V-angle is called the lower V-region. A plurality of first rectangular holes are located on the center line of the V-groove in the upper V-region; a plurality of second rectangular holes are located at the center line between two of the plurality of V-grooves; and a circular hole is located at the center line of the V-groove in the lower V-region.

2. The rotor structure of the permanent magnet motor as described in claim 1, characterized in that: Two magnets are placed in each of the V-shaped grooves.

3. The rotor structure of the permanent magnet motor as described in claim 1, characterized in that: The outer edge of the rotor has multiple magnetic field guiding grooves, and each V-shaped groove corresponds to two magnetic field guiding grooves.

Images