离心压缩机各种变速驱动机的比较和选择

首先介绍了汽轮机、工业燃气轮机、变频电动机(VFD)和变速行星齿轮(VORECON)等各种驱动机的应用情况;其次讨论了三种变速驱动机的特点和比较;第三比较了变频电动机驱动(VFD)和电动机加变速行星齿轮驱动(VORECON)的优越性;第四介绍了选择使用变速行星齿轮驱动(VORECON)的实例;最后推荐变速行星齿轮驱动(VORECON)优先应用于天然气管道增压离心压缩机的变速调速和其他行业。     

Structural behaviour of aeronautical tungsten carbide/carbon-coated titanium ball screws under space thermal-vacuum conditions

In view of the pressing need for improvements in space mechanisms and tribology research work, a thermal high‐vacuum mechanism test facility has been constructed at Rome ‘La Sapienza’ University. The purpose of this facility is to provide fundamental data on the performance of mechanical components and materials in high vacuum in order to test the validity of space mechanism designs. The facility also makes it possible to examine the behaviour of both mechanisms and materials under combined environmental factors, such as ultraviolet radiation, atomic oxygen and temperature. This paper reports on the behaviour of titanium recirculating ball screws provided by Umbra Cuscinetti SpA (Foligno, Italy) under thermal‐vacuum conditions. It is to be noted that these ball screws—well known in the aeronautical field—may be particularly attractive as a new generation of space mechanisms. A solid multilayer film of tungsten carbide/carbon (WC/C) was deposited on screw surfaces as a lubricant and was then compared with the case of no lubrication, which presently appears promising for many mechanisms. In order to compare experimental results, traditional stainless steel mechanisms were also tested and analysed. The requisites imposed by the space environment, as well as by contact mechanical stresses, have given useful information on a preliminary geometrical configuration and choice of materials, both of which are presented in this paper. Thermal‐vacuum effects on overall ball screw efficiency and on ball screw coating friction and wear are also reported and commented on herein as well as numerical contact simulations of crack mechanisms.     

LK-30/2.5QZ气体钻井用空压装置噪声控制

我国气体钻井设备多为国外产品,因其进口交货不及时、售后服务滞后,且设备价格昂贵,严重制约着我国气体钻井技术的进一步发展。为此,我国研制了LK-30/2.5QZ气体钻井用空气压缩机装置以替代进口产品。该装置的工作噪声主要集中在50~600 Hz,呈低频特性,噪声强度达100 dB,噪声控制方案为采用隔声罩阻断噪声传播途径及减振,分别采用了材料吸声、结构吸声、隔声及管路振动控制等降噪隔振措施。经测定,该装置噪声水平为74.8 dB(A声级),降低噪声20~30 dB,达到了较好的噪声控制水平。现场试验结果也表明,机组运转平稳、振动小、噪声低,各项指标都达到了国际同类机型水平。     

多功能辊体堆焊装置在轧钢厂的应用

介绍了多功能辊体堆焊装置的结构及在梅山钢铁公司轧钢厂的应用情况。应用表明：多功能辊体堆焊装置具有预热、堆焊、层间保温、焊后热处理等多种功能，结构紧凑，性能优越，可在很多轧钢厂应用，仅需较少的投资。     

三峡3期围堰碾压混凝土层面抗剪强度试验研究

通过室内对三峡工程三期碾压混凝土围堰芯样抗剪强度进行的本体、裂缝面模拟试验，试验结果表明其碾压混凝土模拟裂缝面抗剪强度满足设计要求。试验结果为围堰安全运行提供了依据，围堰安全运行4年后成功拆除。     

龙开口碾压混凝土重力坝施工过程仿真研究

针对龙开口水电站大坝施工特点,以施工导流方案、坝体结构和混凝土分区、施工期混凝土温度控制措施等为边界条件,综合考虑坝体混凝土施工工艺流程、资源约束及系统运行特征,系统分析了碾压混凝土的运输入仓方式、仓面规划及多种混凝土料性的影响,建立了碾压混凝土坝施工全过程动态仿真模型。通过对龙开口碾压混凝土坝施工进程的模拟,获得了全面详细的坝体混凝土施工过程参数及状态信息。     

柔性成圆辊减振弹簧的优化设计

柔性成圆辊减振弹簧是实现金属罐体成国高速化和柔性化的关键零件。但按常规方法设计出来的减振弹簧，存在短期断裂的隐患。本文提出该减振弹簧优化设计的方法，并在工艺和结构上采取相应措施，从而解决了柔性成圆辊减振弹簧的短期断裂问题。     

螺杆压缩机疑难故障分析和对策

简单介绍了螺杆压缩机的优良性能，同时针对它的常见疑难故障提出了诊断方案，并给出了切实可行的解决办法。     

螺纹钢冷弯裂纹的分析

对螺纹钢筋由冷弯产生的纵向裂纹进行了分析,结果表明,硅酸盐夹杂物分布不均匀是造成螺纹钢筋冷弯纵向裂纹的主要原因,并提出了相应的预防措施。     

一千万吨级露天矿大型成套设备科研攻关的成功创举

建设一千万吨级大型露天矿是我国采矿工业发展的战略需要，而拥有与其相适应的大型成套设备又是此类矿山建设的必备条件。因此，国家批准将“一千万吨级露天矿大型成套设备研制”列为重点攻关项目。经参加攻关单位的共同努力，研制出了多种大型矿用设备。本文着重介绍我院机械研究所与有关单位合作为一千万吨级露天矿建设研制的五大设备的基本特色，并列举了其它单位在这一攻关工作中的设备研制情况。