Incompressible and Analytical Study on Load-Carrying Capacity of a Complex Thrust Gas Bearing

ABSTRACT

A type of aerodynamic/aerostatic complex thrust gas bearing was presented in the investigation of the coupling between aerodynamics and aerostatics with the objective of further improving the performance of the thrust gas bearing. Its analytical model was also set up completely under incompressible conditions. Based on this model, the load-carrying capacity function apparently included pressure and structure coupling items. However, this structure cannot be used when the pressure ratio of the complex gas bearing is less than 1.

     

计算机辅助监控机床颤振的研究

本文主要讨论机床颤振的计算机辅助监控问题。文中提出以特征量ξ做为机床颤振的监测参数,当ξ值超过预先设定的控制门限值时,计算机监测单元即向控制单元发出警报并采用一种特殊的变速控制策略抑制颤振于孕育之中。     

高速微细骨钻过程中切削力与切削温度试验研究

钻骨手术是医学中历史悠久的外科术式之一,现已广泛地应用在颌面修复手术以及修整骨折等方面。钻骨过程中,切削力的大小和切削温度的高低对整个手术的质量有非常重要的影响。此次研究以高速微细切削机床为试验平台,通过一系列试验,研究了骨头高速微细钻孔中进给速度、主轴转速与切削力、切削温度之间的关系,在此基础上为外科手术导航系统的建立提供数据支持。试验结果表明,为了同时保证骨钻过程中的切削力和切削温度都在较低的合理范围内,应该选择高转速和较大的进给量。     

An Investigation into some Mechanical and Metallurgical Properties of Stainless Steel Reinforced Aluminium Alloy Powder Compacts

An experimental investigation into uniaxial tension and transverse bending of thin rectangular sheets made of stainless steel wire mesh and microcable reinforced sintered 6061 aluminium alloy powder compacts was made in order to determine some of their mechanical and metallurgical properties. Theoretical predictions based on the rule of mixtures were made for the ultimate tensile strength and for the Youngs modulus and were compared with the experimental results. Metallographic analysis involved optical and SEM photography on selected specimens and also an "EDAX" analysis on the intermetallic phase formed between the matrix and the reinforcement in order to establish its composition. In general, it was observed that the introduction of the stainless steel reinforcement resulted in extra strength of the reinforced material compared to that based on the net density of the combination.     

往复真空泵平衡气道的设计与节能分析研究

主要对带固定环状阀复真空泵气阀和气缸平衡气道联合作用的结构进行了分析研究,得出了往复真空泵气缸平衡气道的设计计算式,并提出了一种计算回气时间的方法,这对改进往复真空泵的结构,减轻重量,节约能源是至关重要的。