Loss Analysis of Magnetic Gear with Slotted in Magnetic Modulation Ring

In order to improve the operation efficiency of coaxial magnetic gear(CMG),in this paper,a CMG model with slotted in magnetic modulation ring is proposed.In this model,the permanent magnets(PMs)of internal and external rotors are distributed in Halbach array,the inner rotor PMs are equally divided into 3 small pieces,and the outer rotor PMs are equally divided into 2 small pieces.At the same time,the static magnetic modulation ring iron blocks are slotted,each iron block has 3 slots,the width of the slot is 0.4°,and the depth of the single side slot is 1mm.Finally,a two-dimensional model is established,and the eddy current loss and iron loss of the model are optimized,compared with the conventional CMG model,it is found that the changed pattern can increase the internal and external output torque by 4%and 4.12%,respectively.The eddy current loss is reduced by 66.57%,and the iron loss is reduced by 8.9%,which significantly improve the operation efficiency of the CMG.

Analysis of Electromagnetic Performance of Modulated Coaxial Magnetic Gears Used in Semi-Direct Drive Wind Turbines

Wind turbine is a key device to realize the utilization of wind energy,and it has been highly valued by all countries.But the mechanical gear transmission of the existing wind power device has the disadvantages of high vibration and noise,high failure rate,and short service time.Magneticfield modulation electromagnetic gear transmission is a new non-contact transmission method.However,the conventional modulation magnetic gear has low torque density and torque defects with largefluctuations.In order to overcome the gear transmis-sion problems of the existing semi-direct drive wind power generation machinery and improve the electromag-netic performance of the traditional magnetic gear transmission,this paper proposes a new transmission scheme of a non-contact semi-direct drive wind generator with a surface mount Halbach array modulated mag-netic gear method,and considers the electromagnetic properties of the semi-direct drive modulation magnetic gear of the wind turbine.Thefinite element software is used to construct the model of the surface-mounted Halbach array magnetic gear and the conventional gear,analyzed the distribution of magneticfield lines of the two magnetic gears,calculated the air gap magneticflux density of the inner and outer air gap,and obtained the main harmonics of the inner and outer air gap magnetic density;calculated the static torque and steady-state operating torque of the inner and outer rotors in the model,compared the air gapflux density,harmonics and torque of the magnetic gears.The simulation results show that the magneticfield modulation type mag-netic gear of the surface mount Halbach array magnetic gear method improves the magnetic induction wave-form of the inner and outer air gap,reduces the pulse torquefluctuation,and has a 60%higher static torque.Applying it to semi-direct drive wind power generation equipment not only overcomes the shortcomings of mechanical gears,but also has higher electromagnetic performance.Therefore,the surface-mounted Halbach array modulated magnetic gear can be used to replace the mechanical gearbox in the semi-direct drive wind power generation equipment.

An Exact Analytical Method for Magnetic Field Computation and Electromagnetic Torque in a Concentric Magnetic Gear

准确计算磁力齿轮电磁转矩是设计、分析磁力齿轮的关键,采用二维全局解析法计算同心式磁力齿轮气隙磁场。求解场域划分为内外转子永磁体、内外两层气隙和调磁定子的槽形区域,3类子区域的拉普拉斯方程和泊松方程通过边界连续条件建立联系。得到内外两层气隙区域的矢量磁位磁通密度解析表达式,有利于方便、快速、精确地计算任意转子位置的电磁转矩。计算了内外两层气隙磁场和内外转子电磁转矩,将气隙磁场波形和内外转子电磁转矩波形分别与二维有限元法计算波形作比较,结果吻合,证明了方法的正确性和有效性。

Cycloidal Magnetic Gear Speed Reducer

A cycloidal speed reducer employing gears with permanent magnets acting as teeth is described. The magnets, which have their axes radially oriented in both the orbiting gear and the fixed internal gear, are inserted in holes drilled in nonmagnetic rims without protruding from the cylindrical exposed surfaces. Because the orbiting gear is not restrained radially, it contacts the fixed gear and rolls on its inner surface. A normal force is developed at the contact point between the gears to balance the magnetic attraction and the centrifugal force of the orbiting gear. The friction available due to this normal force increases the transmission’s torque capacity, which is further increased by elimination of the gap between the gears. Also, the radial load on the supporting orbiting gear bearing is eliminated. A prototype with a reduction ratio of 26 is being tested.

Recent Developments and Comparative Study of Magnetically Geared Machines

This paper overviews the recent developments and various topologies of magnetically geared(MGd)machines.Particularly,current design trends and research hotspots of this kind of MGd machines are emphasized,with the aid of statistic summary of the published papers.According to different evolutions from a magnetic gear(MG),four mainstreams of MGd machines are extracted and compared in terms of both mechanical complexity and electromagnetic performance.By virtue of their inherent features,such as high torque density and multi-power port,the feasibility of MGd machines for applications,where continuously variable transmission(CVT)and power split are demanded,is also described.

Comparative Study of Novel Axial Flux Magnetically Geared and Conventional Axial Flux Permanent Magnet Machines

In this paper,a performance comparison between the novel axial flux magnetically geared machines(AFMG)and the conventional axial flux YASA machine is presented.The AFMG and YASA machines have the same stator construction in which segments are equipped with concentrated windings to form the stator.However,the AFMG machine has two rotors with different pole-pair numbers.Magnetic gear effect can be obtained to increase the torque density.The performance comparisons at no-load and on-load conditions are then studied by 3D-finite element analysis(FEM).Moreover,both machines are prototyped,tested and compared.

A Novel High Performance Magnetic Gear with Auxiliary Silicon Steel Sheet

Magnetic gear is a transmission device with novel structure.It uses the principle of magnetic field modulation to transmit torque.In view of the magnetic leakage of the magnetic gear in the process of rotation and cannot be eliminated,a magnetic gear model with auxiliary silicon steel sheet is proposed.Based on the conventional magnetic gear structure,the silicon steel sheet is placed outside the permanent magnet of the outer rotor.The magnetization mode of the outer rotor permanent magnet is tangential magnetization,and the spoke structure is adopted,and the inner rotor PMs is surface mounted and magnetized in the radial magnetization.The improved model is simulated by finite element method under three-dimensional conditions,and the electromagnetic performances of the model are optimized.Compared with the conventional magnetic gear model,the improved model has good performance,which improves the transmission capacity of output torque and reduces torque ripple.It is a great significance to improve the performance of magnetic gear.

Magnetic Equivalent Circuit Modeling of an Axial-Field Magnetic Gear

This paper presents a two-dimensional(2D)magnetic equivalent circuit(MEC)model to investigate the magnetic field distribution in the air-gap of an axial-field magnetic gear(AFMG).The MEC model is configured as a meshed reluctance network(RN)with permanent magnet magnetomotive-force sources.The MEC model based on RN is considered as a good compromise between accuracy and computational effort.This is a new model that will allow a faster analysis and design for the AFMG.Flux density in the air-gap is calculated with the proposed model and verified by finite element simulations.

Surface Magnet Gears with a New Magnet Arrangement and Optimal Shape of Stationary Pole Pieces

In mechanical gear systems, dust, noise, vibration, and tooth wear are generated by frictions among gear teeth, and suppressing friction requires lubrication. Magnetic gears transmit torque by magnetic forces without contact and so avoid contact-related problems. The present paper discusses magnet arrangements and the shape of stationary gear teeth to improve transmission torque in surface magnet type magnetic gear transmission mechanisms.

Research on Torque-Angle Characteristic of Large Gap Magnetic Drive System

The principle and design method of the large gap magnetic drive system is studied in this work. The calculation model of the torque-angle characteristic in the large gap magnetic drive system driven by traveling wave magnetic field is established. The calculation model is computed by using MATLAB software, and the pattern of the system’s torque-angle characteristic is obtained by analyzing study results. These results indicate that: torque-angle characteristic and the driving torque of the system can be adjusted by changing the electric current of coil, the magnetization of permanent magnetic gear, the inner diameter of permanent magnetic gear, the coupling distance between electromagnet and permanent magnetic gear, the outer diameter of permanent magnetic gear, and the axial length of permanent magnetic gear.

永磁齿轮增速传动系统研究

基于磁场调制式永磁齿轮运行原理,提出了一种新型磁力增速齿轮传动系统,即将多个高转矩密度的磁场调制式永磁齿轮级联起来,使其成为具有过载保护、隔离冲击与振动且无须润滑等优点的高转矩密度的增速传动系统。通过有限元法详细分析了永磁齿轮增速传动系统中各组成部分的损耗产生机理及影响因素,并通过控制变量法对连接模块永磁齿轮的内外永磁体、调磁环、外转子轭铁等结构进行优化,使得整个增速系统效率提高至91.1%。

磁力齿轮异步电机共用磁轭分析及优化

分析了复合电机共用磁轭厚度对共用磁轭磁密的影响,以及磁力齿轮内转子极对数对复合电机各层气隙磁密和电机性能的影响,提出了两种针对共用磁轭的优化结构。首先,用磁路法进行计算,得出共用磁轭部分在一定磁密条件下的理论厚度和三层气隙中的谐波次数,分析共用磁轭厚度变化对共用磁轭磁密的影响,以及不同次数的谐波对电机性能的影响。然后,为了削弱磁力齿轮和异步电机的相互影响,提出两种新结构,一种在共用磁轭部分加入隔磁层,另一种将磁力齿轮内转子的排列方式改为Halbach阵列。最后,用有限元仿真验证了理论分析的正确性和新结构对电机性能的改进。

一种零泄漏的齿轮泵设计

介绍了齿轮泵的设计过程,从变位系数和压力角两个方面着手,重点阐述了依据排量和中心距设计齿轮参数的选择方法。为实现零泄露,采用了磁性联轴器代替机械密封,结构更紧凑,密封性更好。齿轮泵整体结构小巧,能满足实际需求。

磁阻式磁力齿轮多目标优化设计

结合磁阻式磁力齿轮工作原理及传动性能的分析,以提高电磁转矩和降低转矩脉动为目标进行优化设计。首先,通过田口实验设计方法筛选出对设计目标影响较大的因素,再采用响应面法得到反映优化参数与优化目标之间函数关系的数学模型。然后,进行基于多目标白鹭群优化算法的多目标优化设计,选出最优参数组合。最大输出转矩提高了7.76%,转矩脉动降低了28.76%。最后,通过有限元仿真验证了优化算法的有效性和可靠性,为磁阻式磁力齿轮的设计提供参考。

机器人用同轴磁性齿轮若干基本特性分析及其数值计算

机器人用同轴磁性齿轮受其固有特性的限制,目前难以直接应用于工业机器人,其力矩密度、传动比、空程、背隙和扭转刚度、稳定工作区等关键基本特性的研究尚存不足。为此,以国家标准规定的型14谐波齿轮性能为参考对象,采用类比的方法,运用相关电磁学理论,对与其同等空间大小的同轴磁性齿轮相关性能及其数值计算方法、稳定性以及伺服电动机和同轴磁性齿轮的一体化集成技术进行了研究和对比,指出了扭转刚度不足是制约同轴磁性齿轮用于机器人的关键因素,明确了未来机器人同轴磁性齿轮伺服控制的研究重点。

高温超导磁力传动的发展现状及前景

鉴于高温超导材料具有高载流、强捕获磁场特性与迈斯纳效应,将高温超导材料应用于磁力传动装置,可在实现无接触转矩传输的同时,显著提高转矩密度、传动效率等性能。国内外已开展高温超导磁力传动的理论与应用研究工作,并取得了相应的进展。以高温超导磁力耦合器和高温超导磁齿轮为研究对象,通过调研国内外相关文献,从结构及原理、建模与分析两方面综述高温超导材料在磁力传动领域的研究现状。在此研究基础上,进一步探讨高温超导磁力传动研究在创新拓扑结构设计、冷却与供电、超导磁体交流损耗、复杂传输特性的多目标优化所面临的问题及未来发展前景。

三轴环板式永磁齿轮气隙磁场及转矩计算

利用标量磁位法获得了三轴环板式永磁齿轮(Triple-shaft Ring-plate Magnet Gear,TRMG)的气隙磁场数理模型,根据磁场叠加原理建立了内、外永磁圈间气隙磁场及其相应的电磁转矩模型;由于所有计算均基于TRMG的平面磁场建立,因此,所建模型与二维有限元结果间具有较高的准确度(误差≤5%);其计算速度远快于三维有限元法,且与二维及三维有限元分析具有较好的吻合度与趋势性,验证了所建模型的准确性,可适用于三轴以上的多轴环板式永磁齿轮的磁场分析与结构动力学计算。

基于输出转矩的同轴式磁齿轮设计

同轴式磁齿轮以极高的转矩密度成为机械齿轮的最佳替代。针对同轴式磁齿轮产业化过程中缺乏设计理论的现状,本文提出了基于输出转矩的磁齿轮设计公式。首先,依据输出转矩随各主要设计参数的环比增长率变化规律确定了不同尺寸系列磁齿轮的最佳尺寸值;其次,明确了最大磁能积、调磁环内径平方等与输出转矩间的线性变化关系;最后,通过分析输出转矩随调磁环内径平方变化的斜率、截距受永磁体极对数的影响规律,得到了基于永磁体最大磁能积、气隙系数、气隙长度、漏磁系数、调磁环内径和外磁环永磁体极对数的磁齿轮设计公式。三维有限元仿真算例表明该公式误差不大于5%,三种不同尺寸系列的样机转矩试验也表明该公式计算误差具有较高的精度。基于输出转矩的设计理论可极大地缩短磁齿轮设计周期。

聚磁式转子轴向磁齿轮复合电机的有限元分析

在系统介绍轴向磁齿轮复合电机基本工作原理的基础上,提出了一种具有聚磁式转子的轴向磁齿轮复合电机。采用有限元分析方法对复合电机的电磁性能进行了三维数值仿真分析,验证了电机结构的合理性,并详细分析了聚磁式转子结构参数对电机输出转矩与轴向磁拉力的影响,得出转子参数对转子两侧圆周和轴向磁拉力的影响相似,为后续的试验研究提供了理论参考。