应用层压理论设计高效PC破碎机

针对国内破碎产品粒度偏大，严重影响磨机处理能力的问题，用生产实例说明，应用层压理论研制的PC破碎机不仅能降低破碎产品粒度、提高磨机的处理能力，而且还能减少电耗、降低成本和增加效益。简述了层压理论的原理；介绍了PC破碎机的设计原理、结构特点及优点技术性能优良的PC破碎机，已成为众多厂矿为实现“多辞少磨”目标而选用的理想破碎机。     

基于功能进化的滚动直线导轨创新设计

根据机械产品功能进化的要求,将进化思想运用于创新设计过程,通过结构特征单元的提取与变换,对滚动直线导轨的结构进行了创新设计,实现了基于功能设计产品结构的过程.     

微米级电液位置反馈控制系统的研究

为了研究轴向柱塞泵配流盘/缸体摩擦副的润滑机理，研制了微米级电液位置反馈控制系统.基于该控制系统的组成和工作原理，使用系统中的高精度电涡流微位移传感器对润滑膜厚度进行精密测量.采用比例-积分-微分(PID)控制算法对微米级的润滑膜厚度进行反馈控制，对微米级电液位置反馈控制系统进行了数学建模，并研究了整个电液位置反馈控制系统的动态特性.结果表明，随着V0/βe、Kce的适当减小，润滑膜厚度的振荡幅度减小.适当选取PID参数值可以使系统的振荡周期变短，响应速度加快.微位移传感器的测量误差小于1　μm.该系统可以测量轴向柱塞泵配流盘/缸体摩擦副润滑膜厚度、承载力和泄漏流量.     

川东地区应用螺杆钻具配金刚石钻头钻井

本文介绍了螺杆钻具配金刚石钻头钻井技术特点及工艺要求。通过川东高陡构造直井中深部高密度钻井液井段及定向侧钻井中使用证明:钻井速度提高、钻井成本下降,保证了侧钻井准确中靶,获得了良好的社会经济效益。     

Solder balling of lead-free solder pastes

Solder balling in Sn/Ag/Cu solder pastes was studied in this work. Three different solder pastes, several different reflow profiles and conditions, and two stencil thicknesses were used in the investigation. During the first phase, called the verification phase, the solder pastes were checked to ensure they met the minimum requirements. In the process-screening phase, the reflow profile was varied. Results show that besides flux chemistry, reflow atmosphere plays the major role in solder balling. The average number of solder balls with the best paste was one fifth of that with the worst paste. Furthermore, with all the pastes, the number of solder balls dropped close to zero when nitrogen atmosphere was used. Another finding during the reflow process screening was the influence of the stencil thickness on the solder-balling result. With a thinner stencil, two of the pastes exhibited significant solder balling. This is assumed to be caused by the different ability of fluxes to withstand oxidation during the preheating in the reflow process. In the last phase, the effect of the solder-paste particle size on solder balling was studied more closely. The flux chemistry was kept unchanged, and the solder particle size was varied between type 3 and type 4. The results show that, with type 4 paste, significantly more solder balls are formed compared to type 3 paste. It was also confirmed that, regarding the reflow profile, the ramp-up rate from 150°C to 217°C and the reflow atmosphere were the most significant factors that determine the solder-ball formation for both types of paste.     

空间机构移动副间隙的随机特性分析

在进行运动副间隙的随机特性分析时，应根据运动副受力情况的不同而采用不同的分析模型，运动副受力较小时可以采用随机模型，而当运动副受力较大时就应该采用连续接触模型，本文以移动副为例，分别用随机模型和连续接触模型对空间机构中运动副间隙的随机特性做了详细的分析，分析结果可在进行空间机构运动精度分析时作为理论基础。     

轻烃泵机械密封泄漏原因分析

通过对机械密封摩擦副表面失效及副密封圈用材的研究，寻找机械密封泄漏原因和解决办法。     

EPC球形铸铁件的皱皮缺陷分析

简述了EPC负压铸造在生产球形铸铁件过程中，浇注时，EPS的热变形和皱皮缺陷的形成，提出了减轻和防止皱皮的一些措施。     

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。