基于ANSYS的电主轴结构优化

建立了某铣削用电主轴轴承-转子系统的参数化有限元模型,应用有限元分析软件ANSYS的优化设计功能,以提高电主轴的刚度为优化目标,对主轴的支承跨距和电机转子安装位置进行了优化计算,并对优化前后的主轴系统进行了模态分析,对比了其一阶自振频率的改变情况.结果表明:主轴结构优化后,其刚度和一阶自振频率均有一定程度的提高.     

电主轴最佳跨距理论计算与仿真分析

为研究跨距设计对主轴力学性能的影响,针对某型电主轴,根据经验公式计算最佳跨距的理论值以及进行不同跨距下固有频率与静刚度变化规律的仿真.通过主轴静刚度加载实验,验证主轴轴承刚度,避免对仿真模型产生影响.基于设定的边界条件,建立模态分析仿真模型及静刚度仿真模型;改变主轴跨距,分析其径向1阶固有频率及径向静刚度的变化规律,分...     

高速电主轴结构参数优化设计

文章通过对某高速电主轴进行结构分析，建立了其参数化有限元模型，应用有限元分析软件ANSYS对主轴的支承跨距进行了优化计算，并针对优化后的结构进行模态分析，校核了其一阶自振频率。优化结果虽然使主轴的一阶自振频率略有降低，但却使主轴的刚度有了较大幅度的提高。     

组合机床主要部件刚度的确定方法

本文介绍组合机床静刚度的研究及在径向载荷作用下主轴一套筒部件静刚度的计算方法。     

影响磁悬浮电主轴单元回转精度因素的分析

介绍了磁悬浮电主轴单元的工作原理,对影响其回转精度的因素进行了分析。以拟用于额定功率为2.2 k W且转速可达24 000 r/min的雕铣机中的主轴为例,分析了控制器反应时间不超过10 ms和主轴端部切削力不超过100 N时的主轴悬浮间隙精度、载荷变动量以及控制系统反馈精度对主轴回转精度的影响。结果表明:当前、后径向磁轴承处主轴圆度误差分别不超过0Δ10.002 mm和-0.006mmΔ20.006 mm、主轴端部载荷变动量不超过1 N,主轴回转精度满足加工要求,对提高磁悬浮电主轴单元的工作性能具有重要意义。     

基于ANSYS Workbench的压缩机拆解设备主轴有限元分析

针对大量废弃的家电产品压缩机,设计了一种压缩机智能拆解设备。基于ANSYS Workbench仿真软件对拆解设备的关键部件主轴进行了有限元分析,构建了主轴的三维模型;分析了主轴的静态性能,研究了主轴在工作过程的弯曲刚度和扭转刚度;在实际边界约束条件下对主轴进行了模态分析,得到了主轴的前六阶固有频率和振型,通过一阶临界转速判定了主轴是否存在共振的可能性;以主轴支撑跨距为变量、弯曲刚度为目标,对主轴支撑跨距进行了优化设计。试验结果表明:进行有限元分析和优化后的主轴在压缩机拆解过程中具有良好的精度和稳定性,拆解效果满足要求。     

基于ANSYS的机床主轴结构优化设计

运用APDL建立机床主轴的参数化有限元模型,应用ANSYS优化设计功能,以主轴的重量为优化目标,对主轴的支承跨距、外径、悬伸长度和传动件安装位置进行了优化计算,并对优化结果进行了分析.结果表明:主轴结构优化后,在保证机床各种性能的前提下,主轴重量得到有效的减小.     

车铣复合加工中心电主轴的稳定性分析和实验研究

电主轴单元是车铣复合加工中心的核心功能部件.利用ANSYS对电主轴系统完成了自由模态以及两种考虑轴承支承的约束模态分析.并针对电主轴单元进行了现场实验,测得主轴实际模态.综合分析理论计算与实验结果表明计算的自由模态与主轴实际模态区别较大,模态分析时必需考虑轴承的支承作用,并且用两组弹簧才能很好地模拟QBC型角接触球轴承组的支承约束.设计的电主轴满足工作要求.     

基于主轴轴承运行刚度的高速主轴动力学建模

高速主轴是高速加工关键功能部件之一,其动力学性能对机床加工质量有着重要的影响。基于赫兹接触理论计算了主轴轴承动态运行刚度并构建了主轴轴承的刚度矩阵;基于Timoshenko梁理论获得高速旋转梁单元运动方程;基于主轴轴承单元、梁单元与盘单元构建了某高速主轴系统有限元模型,并进行了静动态实验测试。结果表明:所建立的动力学模型是准确的,为主轴系统结构优化提供了理论指导。     

DVG850高速立式加工中心电主轴的动静态特性分析

针对240XDJ24Y型电主轴的结构特点,在Ansys软件中建立电主轴的三维有限元模型,分析并计算出电主轴的静态变形量与静刚度。结合Ansys软件中的Solid45单元与Combin14单元对电主轴进行动态分析,采用QRDamoned法进行模态提取,得到前6阶的振动特性。分析结果表明:电主轴的静刚度能够满足要求;电主轴的最高工作转速远离临界转速,能有效避免共振现象的发生。     

Effects of Post-weld Heat Treatment on Microstructure,Mechanical Properties and the Role of Weld Reinforcement in 2219 Aluminum Alloy TIG-Welded Joints

In as-welded state, each region of 2219 aluminum alloy TIG-welded joint shows diff erent microstructure and microhardness due to the diff erent welding heat cycles and the resulting evolution of second phases. After the post-weld heat treatment, both the amount and the size of the eutectic structure or θ phases decreased. Correspondingly, both the Cu content in α-Al matrix and the microhardness increased to a similar level in each region of the joint, and the tensile strength of the entire joint was greatly improved. Post-weld heat treatment played the role of solid solution strengthening and aging strengthening. After the post-weld heat treatment, the weld performance became similar to other regions, but weld reinforcements lost their reinforcing eff ect on the weld and their existence was more of an adverse eff ect. The joint without weld reinforcements after the post-weld heat treatment had the optimal tensile properties, and the specimens randomly crack in the weld zone.     

The First Phase of the SRIF Industrialized Base in ＂West Area＂ Has Been Put into Operation

After nearly two years＇ tense construction, the first phase of industrialized base of Shenyang Research Institute of Foundry （SRIF）, located at the Tiexi Casting and Forging Industrial Park in the west of Tiexi District, has now been completed and formally put into operation.     

Effect of Rare Earth Doping on Impedance,Modulus and Conductivity Properties of Multiferroic Composites:0.5(BiLa_xFe_(1-x)O_3)–0.5(PbTiO_3)

The Lanthanum-doped bismuth ferrite–lead titanate compositions of 0.5(Bi LaxFe1-xO3)–0.5(Pb Ti O3)(x = 0.05,0.10,0.15,0.20)(BLxF1-x-PT) were prepared by mixed oxide method.Structural characterization was performed by X-ray diffraction and shows a tetragonal structure at room temperature.The lattice parameter c/a ratio decreases with increasing of La(x = 0.05–0.20) concentration of the composites.The effect of charge carrier/ion hopping mechanism,conductivity,relaxation process and impedance parameters was studied using an impedance analyzer in a wide frequency range(102–106Hz) at different temperatures.The nature of Nyquist plot confirms the presence of bulk effects only,and non-Debye type of relaxation processes occurs in the composites.The electrical modulus exhibits an important role of the hopping mechanism in the electrical transport process of the materials.The ac conductivity and dc conductivity of the materials were studied,and the activation energy found to be 0.81,0.77,0.76 and 0.74 e V for all compositions of x = 0.05–0.20 at different temperatures(200–300 °C).     

Quantitative Analysis of the Crystallographic Orientation Relationship Between the Martensite and Austenite in Quenching–Partitioning–Tempering Steels

The orientation relationships(ORs)between the martensite and the retained austenite in low-and medium-carbon steels after quenching–partitioning–tempering process were studied in this work.The ORs in the studied steels are identified by selected-area electron diffraction(SAED)as either K–S or N–W ORs.Meanwhile,the ORs were also studied based on numerical fitting of electron backscatter diffraction data method suggested by Miyamoto.The simulated K–S and N–W ORs in the low-index directions generally do not well coincide with the experimental pole figure,which may be attributed to both the orientation spread from the ideal variant orientations and high symmetry of the low-index directions.However,the simulated results coincide well with experimental pole figures in the high-index directions{123}_(bcc).A modified method with simplicity based on Miyamoto’s work was proposed.The results indicate that the ORs determined by modified method are similar to those determined by Miyamoto’method,that is,the OR is near K–S OR for the low-carbon Q–P–T steel,and with the increase of carbon content,the OR is closer to N–W OR in medium-carbon Q–P–T steel.     

The Mirror with Patterns of Auspicious Animals and Grapes——Exquisite cast mirror and the technology of surface tin-enrichment by rubbing-in and infiltration of tin-rich powder

<正>Bronze mirrors were used by the Chinese people before the introduction of the glass mirror.Only after it was replaced by the glass mirror did the bronze mirror gradually retreat from people's lives.Different styles of bronze mirrors were made in different historical periods,particularly in the Warring States Period,the Han and Tang Dynasties,which were the three peaks of the development of bronze mirror arts in ancient China.The casting techniques were exquisite.The surface of the bronze mirror was smooth and bright enough to reflect one's image,and there were scarcely any casting defects on the mirror surface.On the back of the bronze mirror,there were rich depictions of Arts and Humanities,and the ornamentations were also     

The 9th China International Diecasting Congress & Exhibition

The 9th China International Diecasting Congress ＆ Exhibition was held on July 22-24, 2014 at Shanghai New International Expc Centre. This exhibition was the most successful over the years, with over 6890 visitors and 155 exhibitors, and the exhibition area increased by 30% from 9,500 square meters in 2012 to 12340 square meters. Die casting enterprises from a total of 24 countries and regions, including China mainland, Chinese Taiwan and Hong Kong, South Korea, Japan, Germany, India, Thailand, Malaysia, the United States, Russia, Australia, Iran, Ukraine, Brazil, Colombia, Singapore, Austria, Canada, Croatia, France, Turkey, United Kingdom, Vietnam, attended the congress and exhibition.     

Introduction of the Fluid Control Engineering Institute of Kunming University of Science and Technology

正The Fluid Control Engineering Institute of Kunming University of Science and Technology was set up in 1996.The researches of institute concentrate on electro-hydraulic(pneumatic)servo/proportional control and hydromechatronics.The Institute is committed to research and development of electro-hydraulic control of high-end technical equipment in ferrous metallurgy refining produc-     

RARE METALS Volume Contents

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Antimony Induced Crystallization of Amorphous Silicon

Antimony induced crystallization of PVD (physics vapor deposition) amorphous silicon can be observed on sapphire substrates. Very large crystalline regions up to several tens of micrometers can be formed. The Si diffraction patterns of the area of crystallization can be observed with TEM (transmission electron microscopy). Only a few and much smaller crystals of the order of 1μm were formed when the antimony layer was deposited by MBE (molecular beam epitaxy) compared with a layer formed by thermal evaporation. The use of high vacuum is essential in order to observe any Sb induced crystallization at all. In addition it is necessary to take measures to limit the evaporation of the antimony.     

A CUMULATIVE FATIGUE DAMAGE RULE UNDER THE ALTERNATIVE OF CORROSION OR CYCLIC LOADING

Fatigue damage increases with the applied loading cycles in a cumulative manner and the material deteriorates with the corrosion time. A cumulative fatigue damage rule under the alternative of corrosion or cyclic loading was proposed. The specimens of aluminum alloy LY12-CZ soaked in corrosive liquid for different times were tested under the constant amplitude cyclic loading to obtain S-N curves. The test was carried out to verify the proposed cumulative fatigue damage rule under the different combinations among corrosion time, loading level, and the cycle numbers. It was shown that the predicted residual fatigue lives showed a good agreement with the experimental results and the proposed rule was simple and can be easily adopted.