Motor rotor structure based on metal 3D printing technology
By applying metal 3D printing technology on the motor rotor, a rotor structure with permanent magnet grooves, ribless rotors and magnetic bridges are designed, and shallow grooves are added to the surface, the problems of high temperature rise and magnetic flux leakage of the traditional motor rotor are solved, and the problem of high temperature rise and magnetic flux leakage of the traditional motor rotor is realized. More efficient utilization of permanent magnets and improved motor performance.
Patent Information
- Application Number
- CN202411536147.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-31
- Publication Date
- 2025-02-11
AI Technical Summary
Traditional motor rotors are prone to high temperature rise when running at high speed or high frequency, resulting in local demagnetization of permanent magnets and problems of flux leakage and eddy current loss.
Using a permanent magnet motor rotor structure based on metal 3D printing technology, the permanent magnet groove is placed equidistantly on the rotor core, and the ribless rotor and permanent magnet magnet bridge are placed on the sides, while adding shallow grooves to the rotor surface to optimize Rotor structure and magnetic bridge design.
It effectively reduces eddy current loss and magnetic flux leakage, improves the utilization rate of rare earth permanent magnets, and enhances the mechanical strength and performance stability of the motor.
Smart Images
Figure CN119420071A_ABST
Abstract
Description
Technical Field
[0001] The present invention belongs to the technical field of motors, and in particular, relates to a permanent magnet motor rotor structure based on metal 3D printing technology. Background Art
[0002] In the field of motor technology, loss and torque are important indicators that affect motor performance. The fundamental cause of eddy current is electromagnetic induction. In permanent magnet synchronous motors, eddy current losses in the rotor are often ignored because the rotor rotates synchronously with the stator magnetic field. In fact, the stator slot effect, the non-sinusoidal distribution of the winding magnetomotive force, and the harmonic magnetic potential generated by the harmonic current in the winding will also cause eddy current losses in the rotor core. Under normal circumstances, the rotor eddy current losses in permanent magnet synchronous motors are very small compared with the copper loss and iron loss of the stator. However, due to poor rotor heat dissipation conditions, these eddy current losses may cause a high temperature rise and cause local demagnetization of the permanent magnet, which is particularly serious in some high-speed or high-frequency permanent magnet synchronous motors. The structural characteristics of the motor rotor (such as the thickness and shape of the core and the structure of the laminations) will affect the degree of eddy current generation. A thicker core will widen the path and loop surface of the eddy current flow, thereby increasing the eddy current loss.
[0003] In traditional motor design, the rotor is usually made of multiple silicon steel sheets stacked together to form an iron core. These silicon steel sheets are formed by stamping and have good magnetic permeability, which can effectively reduce eddy current losses. The rotor surface usually has ribs or grooves, which not only improves the structural strength of the permanent magnet synchronous motor, but also plays an important role in maintaining the performance, stability and efficiency of the motor. Due to its relatively fixed structure, traditional rotors are prone to high eddy current losses during braking and rapid starting, affecting the overall efficiency. The rotor's back electromotive force varies greatly at different speeds, which may lead to reduced control accuracy and affect the smooth operation of the motor. At the same time, traditional rotors also have the problem of flux leakage, which affects the utilization efficiency of rare earth permanent magnet materials. Summary of the invention
[0004] In view of the above problems, the purpose of the present invention is to solve the problem of motor rotor eddy current existing in the prior art, and proposes a permanent magnet motor rotor structure based on metal 3D printing technology.
[0005] The technical solution of the present invention is: the motor rotor structure based on metal 3D printing technology described in the present invention includes a rotor core with a cylindrical structure, a plurality of permanent magnet slots are evenly arranged around the edge of the rotor core, the permanent magnet slots run through the upper and lower end surfaces of the rotor core, and a plurality of ribless rotors separated from the rotor core are arranged on the side of the rotor core.
[0006] Furthermore, one permanent magnet slot corresponds to two ribless rotors.
[0007] The ribless rotor is arranged at two sides of the permanent magnet slot, and the ribless rotor is communicated with the permanent magnet slot.
[0008] Furthermore, a permanent magnet bridge is arranged between two adjacent ribless rotors, and the permanent magnet bridge is separated from the left and right sides of the ribless rotor.
[0009] Furthermore, an axial hole is axially opened at the center of the rotor core.
[0010] Furthermore, the permanent magnet slots are perpendicular to the circular diameter of the rotor core end surface.
[0011] Furthermore, the ribless rotor is parallel to the axial direction of the rotor core.
[0012] Further, two ribless rotor surface shallow grooves are equidistantly arranged on the surface of the ribless rotor;
[0013] Rotor strip-shaped shallow grooves are opened on the surface of the rotor core along the circumferential direction.
[0014] Furthermore, the distance between two shallow grooves on the surface of the ribless rotor is ≤3 mm.
[0015] Furthermore, the permanent magnet bridge is spaced apart from the left and right sides of the ribless rotor by a distance of ≤1 mm.
[0016] Furthermore, the surface of the rotor core is provided with rotor strip-shaped shallow grooves along the circumferential direction, and the upper and lower distances thereof are ≤0.5 mm.
[0017] Metal 3D printing technology, especially the use of high-power fiber lasers, can flexibly manufacture motor cores, with the advantages of high molding freedom and rapid prototyping. This technology not only reduces the complex processing procedures in traditional manufacturing and improves material utilization, but also enables the design of complex structures, thereby improving motor performance. Studies have shown that the use of ribless embedded permanent magnet motor rotor structure can effectively optimize the utilization of rare earth permanent magnets and improve torque density and output power. Overall, metal 3D printing technology shows broad application prospects in the field of motor manufacturing and can promote further improvement of motor performance.
[0018] The beneficial effects of the present invention are: 1. Based on metal 3D printing technology, by optimizing the rotor magnetic bridge and changing the rotor structure, the magnetic flux leakage problem caused by the traditional rotor is solved, and the utilization rate of the rare earth permanent magnet is significantly improved; 2. The method of adding shallow grooves on the rotor surface is adopted to effectively suppress the eddy current loss of the rotor; 3. The rotor pole width parameters are optimized through structural analysis, and the rotor displacement caused by centrifugal force is greatly reduced under the premise of ensuring mechanical strength, which provides a basis for the structural design of the additive manufacturing motor rotor; 4. It can be combined with other technologies to reduce eddy current loss to further improve the motor performance; the invention patent provides an innovative solution to meet the demand for reducing eddy current loss in the field of motor technology, and has broad application prospects and commercial value. BRIEF DESCRIPTION OF THE DRAWINGS
[0019] Figure 1 It is a schematic diagram of the overall structure of the present invention;
[0020] Figure 2 is a radial cross-sectional view of the rotor core of the motor in the present invention;
[0021] Figure 3 This is a comparison diagram of rotor eddy current loss before and after optimization at different speeds under load in the present invention;
[0022] In the figure: 1. rotor core; 2. permanent magnet slot; 3. shaft hole; 4. ribless rotor; 5. permanent magnet magnetic bridge; 6. shallow grooves on the surface of ribless rotor; 7. shallow grooves in rotor strips. DETAILED DESCRIPTION
[0023] The specific technical scheme of the present invention is further described in detail below with reference to specific examples.
[0024] As shown in the figure, a permanent magnet motor rotor structure based on metal 3D printing technology described in the present invention has a built-in motor, including a rotor core 1, which is a cylindrical structure. An axial hole 3 is axially opened at the center of the rotor core 1, and a plurality of permanent magnet slots are equidistantly arranged around the edge of the rotor core 1. The permanent magnet slots 2 pass through the upper and lower end surfaces of the rotor core 1.
[0025] Furthermore, a plurality of ribless rotors 4 separated from the rotor core 1 are provided on the side of the rotor core 1, one permanent magnet slot 2 corresponds to two ribless rotors 4, the ribless rotors 4 are located on both sides of the permanent magnet slot 2, the ribless rotors 4 are connected to the permanent magnet slot 2, the permanent magnet bridge 5 is separated from the left and right sides of the ribless rotor 4 by a distance less than or equal to 1 mm, a plurality of ribless rotor surface shallow grooves 6 are arranged on the surface of the ribless rotor 4, and a rotor strip shallow groove 7 is opened circumferentially on the surface of the rotor core 1.
[0026] Furthermore, the permanent magnet slots 2 are perpendicular to the diameter of the circular end surface of the rotor core 1 .
[0027] Furthermore, the ribless rotor 4 is parallel to the axial direction of the rotor core 1 .
[0028] Furthermore, the distance between the two ribless rotor surface shallow grooves 6 is less than or equal to 3 mm, and the upper and lower distances of the ribless rotor surface shallow grooves 6 opened on the surface of the rotor core 1 along the circumferential direction are less than or equal to 0.5 mm.
[0029] Figure 3 As shown in the figure, the rotor eddy current loss of the original model and the optimized model at different speeds under load is compared. The present invention optimizes the rotor magnetic bridge, changes the rotor structure and adds a shallow groove method. Under the premise of ensuring mechanical strength, the rotor displacement caused by centrifugal force is greatly reduced, the eddy current loss of the rotor is effectively suppressed, and the motor performance is improved.
[0030] Furthermore, the number of the motor permanent magnet slots 2 is 10, and the number of the ribless rotors 4 is 10.
[0031] Furthermore, the number of shallow grooves 6 on the surface of the ribless rotor 4 is 20, and the number of rotor strip shallow grooves 7 on the surface of the rotor core 1 is 9.
[0032] Furthermore, the shallow grooves 6 on the surface of the ribless rotor 4 are rectangular parallelepiped.
[0033] When used specifically, the present invention is limited to built-in motors and is not suitable for surface-mounted motors. The number, shape and position of magnetic barriers are not clearly specified and need to be determined according to the motor application requirements.
[0034] The present invention provides a permanent magnet motor rotor structure based on metal 3D printing technology. By removing the traditional magnetic bridge part in the circumferential direction of the rotor and adding shallow grooves on the rotor surface in a regular manner, the present invention can effectively reduce magnetic flux leakage, reduce eddy current loss, and make the magnetic flux density distribution in the air gap more uniform. This design not only simplifies the manufacturing process of the motor, resulting in higher torque generation and more efficient permanent magnet utilization, but also improves the performance and reliability of the motor.
Claims
1. A motor rotor structure based on metal 3D printing technology, characterized in that: The invention comprises a rotor core (1) having a cylindrical structure, wherein a plurality of permanent magnet slots (2) are arranged at equal intervals around the edge of the rotor core (1), the permanent magnet slots (2) penetrate the upper and lower end surfaces of the rotor core (1), and a plurality of ribless rotors (4) separated from the rotor core (1) are arranged on the side of the rotor core (1).
2. The motor rotor structure based on metal 3D printing technology according to claim 1, characterized in that: One of the permanent magnet slots (2) corresponds to two ribless rotors (4). The ribless rotor (4) is arranged at two sides of the permanent magnet slot (2), and the ribless rotor (4) is in communication with the permanent magnet slot (2).
3. The motor rotor structure based on metal 3D printing technology according to claim 1, characterized in that: A permanent magnet bridge (5) is arranged between two adjacent ribless rotors (4), and the permanent magnet bridge (5) is separated from the left and right sides of the ribless rotor (4).
4. The motor rotor structure based on metal 3D printing technology according to claim 1, characterized in that: An axial hole (3) is axially opened at the center of the rotor core (1).
5. According to claim 1, a permanent magnet motor rotor structure based on metal 3D printing technology is characterized in that: The permanent magnet slot (2) is perpendicular to the diameter of the circular end surface of the rotor core (1).
6. According to claim 1, a permanent magnet motor rotor structure based on metal 3D printing technology is characterized in that: The ribless rotor (4) is parallel to the axial direction of the rotor core (1).
7. According to claim 1, a permanent magnet motor rotor structure based on metal 3D printing technology is characterized in that: Two ribless rotor surface shallow grooves (6) are equidistantly arranged on the surface of the ribless rotor (4); A rotor strip-shaped shallow groove (7) is provided on the surface of the rotor core (1) along the circumferential direction.
8. According to claim 7, a permanent magnet motor rotor structure based on metal 3D printing technology is characterized in that: The distance between the two shallow grooves (6) on the surface of the ribless rotor is ≤3 mm.
9. The permanent magnet motor rotor structure based on metal 3D printing technology according to claim 3 is characterized in that: The permanent magnet bridge (5) is spaced apart from the left and right sides of the ribless rotor (4) by a distance of ≤1 mm.
10. The permanent magnet motor rotor structure based on metal 3D printing technology according to claim 7, characterized in that: The surface of the rotor core (1) is provided with rotor strip-shaped shallow grooves (7) along the circumferential direction, with the upper and lower distances being ≤0.5 mm.