电力机车电机换向器变形量的激光检测系统

提出一种检测电力机车电机换向器变形量的新方案,在防振平台上安装双频激光干涉仪、过零发讯传感器、截面位置限位开关和高精度导轨,并以微电机自动控制二维运行的滑板、滑块为拖动装置.在车间现场环境条件下实时、动态测量电机换向器动压成形"超速"前、后直径值,通过微机数据处理,比较变形量,进行质量评估,打印输出结果.该系统性能稳定、精度高.     

电力机车电机换向器变形的激光检测系统

提出一种检测电力机车电机换向器变形量的新方案,在防振平台上安装又频激光干涉仪、过零发讯传感器、截面位置限位开关和高精度导轨,并以微电机自动控制二维运行的滑板、滑块为拖动的装置。汽车间现场环境条件下实时,动态测量电机换向器动压成形“超速”前、后直接径,通过同机数据处理,比较变形量,进行质量评估,打印出。该系统性能稳定、精度高。     

直流电机换向器故障分析与检修

本文分析了直流电机换向器的常见故障，产生损失的原因，介绍了对换向器的检查办法和修复工艺。     

发动机气缸早期磨损的原因分析

对发动机气缸的磨损机理、一般规律进行介绍,并对其产生原因进行分析,从而提出对发动机气缸早期磨损的预防措施。     

基于旋转分流的同向换向器流量测量模型及实验研究

针对水流量标准装置中不同向开式换向器带来误差问题,研制了一种旋转分流型的同向换向器,分析了新换向器工作原理,建立了新换向器流量测量数学模型;根据流量测量数学模型推导过程得出了流量测量结果不受脉冲触发位置、流速分布及换入-换出时间影响的结论。在水流量标准装置上对新研制换向器进行了实验,结果表明:新换向器较好地克服了不同向换向器对流量测量带来的误差问题,可以代替不同向换向器用于水流量标准装置进行流量测量。     

直流电动机故障检测研究

直流电机由定子和转子两个基本部分组成,直流电动机的故障主要集中在电枢绕组、换向器、电刷等部分,因此,在分析直流电动机故障时应重点注意这几部分,主要从绕组、换向器、电刷等几个方面进行检测。     

两种换向器在液体流量标准装置中的应用

介绍了闭式换向器和开式换向器在液体流量装置中的应用,重点分析了闭式换向器在不同流量下的运行情况,并与开式换向器的工作原理进行了比较。     

磨损表面在线自修复研究

磨损是导致机械零部件失效的主要原因,如何在线修复摩擦表面早期出现的磨损,延长机械设备的工作寿命是当前研究的热点.以锌超细粉体作修复剂,利用摩擦磨损试验机对已磨损金属表面进行了在线自修复试验,并对修复表面的形貌、成分、微观硬度等进行了分析测试.结果表明:所制备的修复剂对磨损表面具有明显的修复作用,形成了修复层.由于金属摩擦副的材质和工作条件的不同,对修复剂、在线自修复工艺等也有不同的要求.提出了油润滑下金属摩擦副磨损表面在线自修复的系统设计.     

关于热能表标准装置中闭式换向器的应用

热能表标准装置由水泵、控温水箱、试验管路、标准流量计组、称重设备、控制设备、加热系统等组成。它和一般液体流量标准装置的结构和工作原理基本一致．区别在于介质需要保持一定的温度。一般液体流量标准装置的换向器是开式的（如图1所示）．而在热水装置上的换向器是闭式的．原因是如果采用开式换向器．在水温较高时，水容易蒸发．从而造成流量计量不准确。二者在结构上有很大区别。     

微系统用超声微电机的研究现状和发展趋势

 微电机是微机电系统(MEMS)的核心，超声微电机是一个新的发展方向．这几年发展十分迅速． 首先对比分析超声微电机与电磁型微电机和静电微电机的区别，对国内外现有的几种超声微电机及其发展趋势进行了介绍和分析，指出目前超声微电机发展存在研究定位不明和关键技术尚未完全解决两大问题。并提出了今后超声微电机发展的研究定位和必须解决的一些关键技术，其应用重点是军民两用，特别是军工． 最后，指出市场牵引和工程实现是超声微电机取得突破的关键因素的同时，政府、产业和研究单位各方面的重视和形成合力则是推进我国超声微电机研究和产业化的关键．     

EPS电机摩擦噪声特性分析与控制

电动助力转向系统代替液压助力转向系统是汽车节能减排的重要措施之一,但前者存在噪声相对较大的缺点。针对某型电动助力转向系统在转动方向盘时产生明显异响的问题,采用主观评价与客观数据相结合,实验手段与信号分析相结合的研究方法,识别出噪声源,以及异响信号的时频特性。结果表明,该型电动助力转向系统电机产生噪声的原因,主要是电刷与换向器的摩擦力传递到电机外壳及附近部件上,激起结构振动所辐射的噪声引起的。在针对性地采用减小摩擦激振力和提高电机外壳刚度的措施后,异响明显改善,声学性能明显提高并已优于进口同类电机。     

潜水电泵失效检测技术与方法

 按照潜水电泵80%～90%的失效或故障是由其机械密封和轴承的失效引起的实际情况,及潜水电泵其他故障的产生一般会引起电机电流增大的原理,提出通过检测机械密封和轴承是否失效、电流变化是否超标,来判断小型潜水电泵是否失效的检测方法。根据水泵机械密封主要是因端面过量磨损而产生泄漏,轴承则因润滑不良导致早期磨损而引起泵体振动的失效机理和特征,提出通过检测水泵密封腔的含水量和泵体振动加速度的大小来判别机械密封和轴承是否失效的方法和技术。研制开发了小型潜水电泵的失效检测系统,通过试验确定并验证了相应的失效判据。     

制动盘早期磨损失效分析

对失效的汽车制动盘进行了扫描电镜分析、化学成分分析、金相检验和硬度检测等。结果表明，制动盘属于早期磨粒磨损失效。对进口和国产的制动盘及制动片进行了对比分析，讨论了材质及摩擦付匹配对制动盘使用性能的影响。制动盘磨损性能的影响因素不仅与制动盘材质有关，更主要是与摩擦片的材质与摩擦副匹配有关。     

Beurteilung des Motorenverschleißes zur Bewertung von Motorenölen

Determination of wear in internal combustion engines for evaluating of motor oils For evaluating the wear performance of motor oils the objective determination of the actual extent of wear is especially difficult, for the process of wear is rather complex. This is above all applicable to cylinder wear, for often it is impossible to distinguish definitely between wear and deformation. Because the direction of maximum wear at several tests must not be maintained exactly and because it is difficult to find exactly the same point for measurement at comparison tests, there must as possible carried out circumferential measurements and generatrix measurements for the determination of maximum wear. For defining an allowable maximum wear in specifications there must stated some tolerances, otherwise in critical cases an unjustified classifying of several motor oils may not be excluded.     

The thyristor commutatorless motor

The commutatorless motor (CLM) is a type of a dc motor whose commutator is replaced by the thyristor power converter. The thyristors are switched by the signals from a position sensor connected to the rotating shaft of the synchronous motor. Therefore, the CLM never loses synchronism and has the good speed characteristics of a dc motor. The current type CLM, having a current smoothing reactor, was studied and found to have better characteristics than the voltage type. In this paper two kinds of the current type CLMs are described; one is the dc CLM using an inverter, the other the ac CLM using a cycloconverter.     

The wolfson magnetic levitation project

The Wolfson magnetic levitation project is concerned with the construction of a 500 m long test track and vehicle, levitated electrodynamically by means of superconducting magnets. The general design features and present status of the project are described. The particular aspects which are discussed include the guideway design, the cryogenic system and superconducting coils, and both the linear synchronous and commutator motor propulsion systems having powered track windings.     

The wear characteristics of thrust washer in conflux planetary gear train of power shift transmission

The wear between planet gear and thrust washer has been investigated based on the thrust washers in planetary transmission. The reasons leading to the wear failure are studied and the measurements for the reduction of abrasive wear are also exploited. A typical wear failure of thrust washer has been analyzed in terms of macromorphology observation, SEM observation of microstructure, material composition test, the metallographic analysis on radial cross section, and microhardness testing. Oil viscosity, oil contamination, and element spectra are analyzed and used to interpret the failure reasons. Through comprehensive analyses of metallographic structure and microhardness, the temperature distribution of thrust washer is obtained, which demonstrate that the adhesive wear is the main wear type for thrust washer although the fatigue wear is also observed. The most wear of thrust washer can be attributed to the great axial force during the working process, which leads to big contact stress. The high temperature at friction surfaces could surpass critical temperature and cause phase transition of austenite in the material. Inadequate cooling effect due to lack of lubrication oil is the main reason for high temperature caused by wear. Upon the comprehensive analyses, in the last section of this work some measurements are put forward for the reduction of the wear.     

聚苯酯基复合材料在超声电机中的磨损性能

作为行波超声电机的接触层摩擦材料,聚苯酯基复合材料的磨损性能对电机的驱动特性和寿命均会产生重要的影响。将聚苯酯基复合材料粘贴在40型圆盘形行波超声电机定子齿面,在不同的电机驱动方式和摩擦组合下测试接触层磨损性能,并使用扫描电镜观察磨损表面形貌。结果表明,超声驱动下,电机接触层以疲劳磨损为主要磨损机制。并且当电机采用聚苯酯基复合材料和铜转子的摩擦组合时,其性能磨损较好。接触界面应力模拟分析表明,行波超声电机接触界面在短时间内即可完成108周次以上的疲劳载荷作用,因此接触层主要磨损机制为超声疲劳。     

Fatigue Failure Analysis of a Grease-Lubricated Roller Bearing from an Electric Motor

The grease-lubricated roller bearing of an electric motor that drove a supply blower suddenly failed during operation. In order to identify the causes of the failure, a variety of characterizations were carried out. The failed surfaces of the bearing were observed visually and microscopically, and the characteristics of the lubricating grease were also investigated. Results showed that the surface of the inner ring of the bearing contained contact fatigue damage, and was covered with a multitude of debris and contact fatigue pits. What’s more, the lubricating grease was subjected to severe thermally induced degradation due to high service temperature, which consequently resulted in the decrease of the lubricating capacity of the grease. Thus, the lubricant film in the roller/raceway contacts was not formed effectively and the lubrication of the roller bearing was poor. As a result, serious local wear as well as contact fatigue damage were brought about on the roller and raceway and the wear finally led to the failure of the bearing.     

Topology optimization of a single-phase induction motor for rotary compressor

The oil circulation rate of the rotary compressor is a crucial factor affecting the performance and reliability of air-conditioning systems-too much oil in the refrigerant-oil mixture causes poor heat transfer and early failure of parts; too little oil means excessive friction and wear of the journal bearing. In this paper, we show how finite-element analysis and topology optimization of a single-phase induction motor of a rotary compressor can be used to reduce the oil circulation rate to the minimum safe level. We analyze the nonlinear transient characteristics of the single-phase induction motor for the rotary compressor by using the program FLUX2D. We optimize the topology of the electromagnetic systems by using finite-element analysis. For validation, we have manufactured and tested optimized induction motors.