CN-119581168-B - Functional magnetic ring with unequal outer diameters and magnetizing method thereof

CN119581168BCN 119581168 BCN119581168 BCN 119581168BCN-119581168-B

Abstract

The invention relates to a functional variable-thickness magnetic ring with an outer diameter and a magnetizing method thereof, which belong to the technical field of permanent magnet motors, wherein the variable-thickness magnetic ring is circular in inner diameter and is a change curve in outer diameter, the thickness of the change curve of the outer diameter is unchanged at a main magnetic pole part, the thickness of the change curve of the outer diameter is reduced at a transition position between adjacent main magnetic pole parts, and the variable-thickness magnetic ring is made of bonded NdFeB materials. The invention is composed of a bonded NdFeB magnetic ring with a functionalized outer diameter and a multipole magnetizing clamp matched with the bonded NdFeB magnetic ring, wherein the outer diameter of the magnetic ring adopts two functionalized sizes, and the harmonic component of the magnetic ring surface magnetism is regulated and controlled by reducing the thickness of a magnetic pole transition zone, so that the amplitude of cogging torque is reduced. The multipole magnetizing iron core matched with the magnetizing clamp can magnetize the magnetic ring into a plurality of magnetic poles with alternately distributed surfaces.

Inventors

WANG LI
WANG YINAN
YU JUNTAO
ZHOU YUANJUN
WANG HUI
WANG XINLING
Peng Chuanxiao
CHENG YUN

Assignees

山东大学
山东山博电机集团有限公司
威海全新电机有限公司
山东大学威海工业技术研究院

Dates

Publication Date: 20260508
Application Date: 20241211

Claims (4)

1. The functional magnetic ring with the unequal thickness is characterized in that the magnetic ring with the unequal thickness has a circular inner diameter and a change curve outer diameter, wherein the thickness of the change curve of the outer diameter is unchanged at the main magnetic pole part, and the thickness of the change curve of the outer diameter is reduced at the transition position between the adjacent main magnetic pole parts; The magnetic rings with different thicknesses are made of bonded NdFeB materials; the outer diameter of the magnetic ring with different thickness meets the following conditions: Wherein, the The outer diameter of the magnetic ring is optimized; The outer diameter of the original magnetic ring; for the pole cutting parameter, the following is satisfied: , the inner diameter of the magnetic ring; The number of the magnetic poles; ; Or alternatively Wherein, the The outer diameter of the magnetic ring is optimized; The outer diameter of the original magnetic ring; for the pole cutting parameter, the following is satisfied: , the inner diameter of the magnetic ring; The number of the magnetic poles; ; In determining the cutting parameters When according to In finite element simulation, set up The range of the values is as follows Setting a value step length according to solving requirements, and solving all possible steps Selecting the lowest magnetic harmonic distortion rate of the table Taking the value as a final result; The magnetizing method of the functionalized magnetic ring with different outer diameters comprises the steps of completing magnetizing by means of a magnetizing clamp, wherein the magnetizing clamp comprises a base, a magnetizing iron core, a winding and a positioning device, wherein the winding adopts enamelled copper wires; When magnetizing, the magnetic ring is placed on the magnetizing iron core and fixed by adopting the positioning device, the two ends of the winding are respectively connected with the positive electrode and the negative electrode of the pulse power supply, so that the magnetizing can be conducted by electrifying, and the magnetic ring structure is taken out after the power is off to complete the magnetizing; The base is provided with a groove, the inside of the groove is used for placing a magnetizing iron core, and the center of the groove is provided with a positioning column for positioning the magnetizing iron core; The magnetizing iron core is provided with a through hole and a winding groove, and the winding groove is used for installing a winding; A slot opening is formed between the winding slot and the through hole, magnetizing positions are formed between adjacent slot openings, the positioning device comprises a disc and positioning plates which are circumferentially and uniformly distributed on the disc, the disc is placed in the through hole on the magnetizing iron core and is clamped in the slot opening, the magnetic ring is sleeved in the positioning device, and the positioning plates correspond to transition positions of the magnetic ring and play a role in limiting circumferential rotation of the magnetic ring.
2. The functionalized magnetic ring with unequal outer diameters according to claim 1, wherein during the manufacture, the raw materials are melted at high temperature to form an alloy by a casting or smelting method, the alloy is crushed and ground after being cooled to prepare nanoscale powder, the nanoscale powder is mixed with a binder to obtain a mixture, the mixture is molded by a pressing or injection molding process to form a blank body with a required shape, the molded blank body is solidified, the binder is fully crosslinked, the mechanical strength of the magnet is enhanced, and a final product is obtained after post treatment and surface treatment.
3. The functionalized outer diameter differential thickness magnetic ring as recited in claim 2, wherein said adhesive is epoxy or polyurethane.
4. A functionalized magnetic ring with unequal thickness according to claim 3, wherein the number of positioning plates is the same as the number of poles.

Description

Functional magnetic ring with unequal outer diameters and magnetizing method thereof Technical Field The invention relates to a functionalized magnetic ring with unequal outer diameters and a magnetizing method thereof, belonging to the technical field of permanent magnet motors. Background A permanent magnet motor is a motor that generates a magnetic field using permanent magnets, and is generally used to convert electrical energy into mechanical energy. Compared with the traditional motor, the permanent magnet motor reduces the electric energy loss because no current is required to be supplied for excitation, has higher efficiency and is particularly excellent under the middle and low speed running condition. Compared with the traditional motor, the permanent magnet motor can realize smaller volume and lighter weight, and is particularly suitable for application scenes with higher requirements on weight and space and high power output, such as the fields of electric automobiles, aerospace and the like. With the continuous acceleration of industrial development, various fields put higher demands on the performance of the micro-motor, wherein lower torque pulsation is one of conditions for ensuring the stability of the micro-motor in a high-speed high-power state. Torque Ripple (Torque Ripple) is Torque Ripple generated by an electric motor due to electromagnetic causes during operation, and is represented as periodic Ripple of output Torque. Torque ripple is mainly caused by cogging torque, which is torque ripple due to reluctance variation between the permanent magnets and the stator teeth, and current harmonics, which interact with surface magnetic flux density harmonics of the permanent magnets to also generate torque ripple. Torque ripple affects smooth operation of the motor, especially in applications requiring precise control, such as robots, servo motors, and electric vehicles. At the same time torque ripple reduces efficiency and accuracy, and due to the torque ripple, the motor can produce unwanted vibrations and noise during operation, resulting in energy losses. For applications requiring high precision position control, torque ripple also reduces the positioning accuracy and responsiveness of the system. At present, one main method for reducing torque pulsation is to reduce cogging torque, and the main methods include optimization of slot pole proportion, chute design, permanent magnet segmentation, oblique pole design and the like, but in long-time market application, some obvious problems appear: 1. the method for optimizing the slot pole ratio does not need to carry out complex modification on the stator or rotor structure, but certain specific application requirements limit the optional slot pole ratio range, so that ideal combination cannot be found. Meanwhile, the optimized slot pole proportion has limited comprehensive optimization on performance, and can reduce cogging torque, but does not necessarily have an optimization effect on other performances (such as efficiency, output power and the like) of the motor; 2. The design method of the chute reduces the amplitude of the cogging torque by chamfering the stator slot, and the fluctuation of the cogging torque is dispersed to a wider angle range. However, the chute design increases the difficulty and cost of stator processing, and the impact of processing errors is greater, especially in high power or precision requiring motors. Meanwhile, the chute can increase electromagnetic noise and eddy current loss of the motor and is unfavorable for heat dissipation of the stator. 3. The permanent magnet segment or oblique pole design can effectively smooth the magnetic resistance change by setting the permanent magnet segment or oblique pole, thereby greatly reducing the cogging torque. But the design and manufacture of the segmented or oblique permanent magnet are more complex, the assembly precision requirement is higher, and the production difficulty and cost are increased. Due to permanent magnet segments or tilting, the utilization of the magnetic flux may decrease, possibly affecting the power density of the motor. There is currently no better solution to the above problems. Disclosure of Invention Aiming at the defects of the prior art, the invention provides a functionalized magnetic ring with unequal outer diameters and a magnetizing method thereof, so as to solve the problems of complex optimization process, complex processing and high assembly precision requirement in the existing torque pulsation optimizing technology. The invention adopts the following technical scheme: the inner diameter of the functionalized magnetic ring with unequal thickness is circular, the outer diameter of the magnetic ring with unequal thickness is a change curve, wherein the thickness of the change curve of the outer diameter is unchanged at the main magnetic pole part, and the thickness of the change curve of the outer diameter is reduced at the transiti