XGL-1100型曲轴连杆颈磨床液压系统

介绍了自行研制的XGL-1100型曲轴连杆颈磨床液压系统的组成结构和原理.该系统工作可靠、运行稳定,满足了新型曲轴磨床对液压系统的性能要求,已应用在研制的数控曲轴磨床上,取得了很好的效果.     

基于动力学仿真和有限元分析的曲轴疲劳寿命计算

在对某型六缸汽车发动机曲轴系动态仿真和对曲轴进行静态有限元分析基础上对曲轴的疲劳寿命进行了计算。首先对曲轴系进行动态仿真,得到曲轴连杆颈处的载荷和载荷谱,载荷作为曲轴有限元分析的力边界条件,而栽荷谱经过简化,得到计算曲轴疲劳寿命的载荷谱,同时利用弹簧单元对主轴颈处的弹性支撑实际状况进行了模拟,也考虑了相邻拐的影响,然后在有限元分析的基础上分别利用S—N和局部应变法计算了曲轴的疲劳寿命,得到的结果说明传统的计算过于保守,这不但对曲轴的设计和优化有一定的意义;也说明再制造发动机时直接利用曲轴其寿命是可靠的,足以维持下一个生命周期。     

曲轴系统动力学特性的数字化仿真与试验研究

利用ADAMS建立了一种柴油机曲轴系统的刚性体和柔性体的动力学模型,通过仿真测试,得到柴油机的主轴承载荷,活塞侧向力等仿真数据,并针对两种系统分别对其特性进行了比较分析,将计算结果与试验结果进行比较,证明了仿真分析的可靠性,为此类型柴油机的曲轴轴系动力学耦合分析和优化设计提供了依据。     

火车车轮轮辋超声相控阵检测

采用某超声相控阵检测设备对火车车轮轮辋做检测,检测结果表明相控阵设备具有灵敏度高、覆盖范围广、能多角度检测、曲线显示直观等优点。对超声相控阵检测同仁有一定借鉴意义。     

基于adams／vibration的内燃机机体振动特性研究

本文以一台多缸柴油机为例,采用结合有限元法（FEM）的多体系统仿真（MSS）方法,建立了内燃机机体振动特性分析模型。通过仿真分析,得出了机体主要激励对应的机体表面振动传递函数。     

Optimization of desiccant wheel speed and area ratio of regeneration to dehumidification as a function of regeneration temperature

Numerical simulation has been conducted for the desiccant wheel, which is the crucial component of a desiccant cooling system. The mathematical model has been validated by comparing with previous experimental data and numerical results. The calculation results are in reasonable agreement with both, experimental and numerical results. As the key operating/design parameters, the wheel speed and the area ratio of regeneration to dehumidification have been examined for a range of regeneration temperatures from 60 °C to 150 °C. Optimization of these parameters is conducted based on the wheel performance evaluated by means of its moisture removal capacity (MRC) which is more appropriate than effectiveness as a performance index of unbalanced flows. Also the effects of the outdoor air temperature and humidity on the optimum design parameters are examined.     

用两极限位置导引刚体并具有最佳传动角的机构综合

介绍了利用曲柄摇杆机构的两极限位置导引刚体,并使机构具有最佳工作传动角的图解设计方法。该方法无需优化计算或查图表、简单易行,具有一定实用价值。     

适用于星敏感器的星图识别方法

采用星敏感器测卫星姿态是现行方法中精度最高的 ,其关键是星图识别。阐述了只采用观测星的位置信息 ,利用观测星图与导航星表的星对角距进行聚类匹配 ,根据观测星图的连通性进行匹配识别的方法 ;用图论理论解释了星识别过程 ;介绍了导航星的选取规则、导航星库的存储内容及采用球矩阵存储和读取导航星库的方法 ;用 1 2 0 MHz主频的微机模拟分析了门限和位置噪声对识别及识别时间的影响。在门限取 0 .0 5°,位置噪声 (单轴 )δ=0 .0 2°以下时 ,在任一区域的识别率达 1 0 0 % ,识别时间平均少于 0 .2 s。     

3D graphical evaluation of micron-scale protrusion topography of diamond grinding wheel

A new graphical evaluation of micron-scale wheel protrusion topography is proposed by using 3D coordinate data derived from contact measuring of 180 diamond grinding wheel. The objective is to quantify 3D distribution of grain protrusion height, gain rake angle and grain relief angle on wheel working surface in dressing. First adaptive measuring was conducted on the base of topographical curvature to identify grain cutting edge in 3D space, second grain protrusion mode was established by polar coordinate transfer so as to ascertain datum plane of grain protrusion, then linear approximation graphics was conducted to display wheel protrusion topography, finally distributions of gain rake angle and grain relief angle were investigated with reference to grain protrusion height. Analytical results show that higher outer grains have more and shaper cutting edges, but lower layer grains retain approximately original crystal forms. In wheel protrusion topography, grain protrusion heights, grain rake angles and grain relief angles are dispersedly distributed in the range 0–28 μm, −45.0° to −89.1° and 1.2–73.1°, respectively, which can be increased by dressing. It is concluded that 3D grain protrusion attitudes distributed on wheel working surface can be quantified by 3D graphical evaluation method.     

Y06108 ZQ铁型覆砂曲轴产生灰化的原因及解决办法

对YC6108ZQ曲轴灰化原因进行了分析,通过采用铁型覆砂铸造工艺和工艺过程的控制等几方面的结合,明显提高曲轴整体质量水平,按此工艺生产,基本解决了灰化问题。