Quick Profile Die Balancing of Automotive Rubber Seal Extrusion by CAE Technology

The extrusion process of a type of automotive rubber seal was considered by using Computer Aided Engineering (CAE) technology. Based on the die balancing requirement, CAE technology was utilized to speed up the die development and balancing process. The rubber material was EPDM and unacceptable extrusion deformation was found by using a parallel die. More balancing dies were then designed following the procedures proposed by the die balancing method and the effect of them was evaluated with respect to CAE analytical results. It was found that the addition of an opening section in the die would provide a more uniform velocity distribution at the die exit than the parallel die. The length of opening section was also found to affect the die balancing and so an optimum length of the opening section was determined by CAE analysis. Further optimization of the die was carried out by adjusting the local length of the opening section. Finally, a real die was cut based on the optimization results and used for production. Ideal profile products were obtained and very small and acceptable deviation from the die was observed, which validated the advantage and accuracy of CAE technology combined with die balancing requirement.     

高压密封消解技术在电厂盐垢分析中的应用

利用高压密封消解技术来消解蒸汽汽轮机叶片上的盐垢,确定了理想的消解体系及消解条件,能比较方便,快捷地完全消解盐垢,并对消解后的元素分析测定作了相应的研究,结果令人满意,本法的SiO2和Fe^3 的标准加入回收率分别为95％－101％和97％－108％。     

金属往复滑动摩擦振动形成机理的实验研究和分析

在材料试验机上对小位移（位移幅值≤5mm）金属往复滑动摩擦振动了实验研究,测量了滑动过程中摩擦试件振动的加速度及摩擦力,分析结果表明,除摩擦系数和相对滑动速度以外,静摩擦系数的变化时间参数τ对摩擦振动影响较大,同时还提出了时间参数τ对摩擦振动影响的理论解释,并在专门设计的试验装置上进行了验证。     

高压密封消化罐在光谱分析样品前处理中的应用

原了吸收光谱法是进行元素定量分析的快捷有效的方法,但固体试样溶解的不完全会对其分析测定的准确度带来很大影响。本文应用高压密封消化罐对电厂难溶的垢样进行消解,对消解条件进行了探索试验,确定了比较方便快捷、溶样完全的消解体系。并对垢样消解液中的一些常规元素作了相应的原子吸收光谱测定。     

激光加工多孔气体端面密封的静压性能研究

采用有限元方法求解二维气体雷诺方程,研究激光加工多孔端面气体润滑密封的静压性能.主要分析了密封端面的微孔面积比Sp、开孔比γ、无量纲孔深ε和密封压力Po对开启力增幅△Pav、泄漏量Q、开漏比E、刚漏比Ek等密封性能参数的影响规律,结果表明,当Sp=0.65,γ=0.6,ε=3.0时可确保密封在静压条件下具有优异的性价比.研究结果为密封的优化设计提供了依据.     

小牛血清边界润滑条件下西佛碱铜配合物改性超高分子量聚乙烯往复摩擦磨损行为

采用自行研制的往复摩擦磨损试验机,在小牛血清边界润滑条件下,研究了含5wt%?10wt%?15wt.%乙二胺缩水杨醛西佛碱(Schiffbase)铜(Ⅱ)配合物的改性超高分子量聚乙烯(UHMWPE)与钛合金(Ti6Al4V)配副的往复摩擦磨损性能.利用扫描电子显微镜及白光共焦三维轮廓仪观察其磨损表面形貌,采用EDS和XPS分析磨损表面的主要元素组成及其价态,并探讨其磨损机理.结果表明:在15%质量分数范围内,随乙二胺缩水杨醛Schiff碱铜(Ⅱ)配合物加入量的增加,改性UHMWPE与钛合金配副的摩擦系数逐步降低,耐磨性逐步提高;磨损机制均为三体磨料磨损.     

磁性流体密封的优化设计

通过数值计算及实验对磁性流体密封的结构与参数进行了优化设计,给出了磁钢材料及尺寸的设计原则,研究了单级密封的密封压差与磁极斜角、极尖宽度和密封间隙的关系。分析了多级密封的级数、齿宽、槽宽及齿高对磁性流体多级密封的影响,给出了最优取值范围。     

Non-contact method used to determine the swelling/shrinking coefficients under CO2 sorption/desorption on an HNBR O-ring - Study of coupling with temperature and pressure

To make use of an O-ring under different pressures and temperatures and to procedure predictive numerical simulations of its use, it becomes important to identify the O-ring behavior under coupled CO₂ sorption (i.e. swelling) and desorption (i.e. shrinking) together with the effect of temperature. Therefore, the presented study deals with an experimental non-contact measurement technique to identify the swelling and shrinking coefficients during pressurization and depressurization under carbone dioxide (CO₂) of an HNBR O-ring. In order to ensure the feasibility of CO₂ sorption (or desorption) measurement from the non-contact method, a purely thermal expansion test permits to identify the thermal expansion coefficient of HNBR, which is well known by other methods including a standard. Numerical simulations complete this section. The simulations ensure that the chosen analysis methodology allows direct identification of swelling and shrinking coefficients and thus determine the seal volume change. CO₂ pressurization and CO₂ depressurization tests at pressures (2, 4 and 6 MPa) under isothermal conditions (60 and 130 °C) and a coupled temperature-pressure CO₂ tests are conducted. The measurements made during these tests show that the CO₂ swelling and shrinking coefficients are independent of pressure but temperature dependent. Besides, a good measurements reproducibility was observed and the order of magnitude of these coefficients leads to a strain in the same order as the thermal strain.     

磁性流体高压密封能力的计算与试验研究

本文根据磁性流体密封理论对磁性流体高压密封进行了密封能力的计算和试验研究,提出了单级与多级密封能力的计算方法,并且通过磁场的数值计算对密封能力进行了定量分析。所设计的多极-多级密封装置的密封压差可达1.4MPa。文章最后还对计算值与试验值之差异作了分析与探讨。     

The effect of texture on the shaft surface on the sealing performance of radial lip seals

On the basis of elastohydrodynamic model,the present study numerically analyzes the effect of various microdimple texture shapes,namely,circular,square,oriented isosceles triangular,on the pumping rate and the friction torque of radial lip seals,and determines the microdimple texture shape that can produce positive pumping rate.The area ratio,depth and shape dimension of a single texture are the most important geometric parameters which influence the tribological performance.According to the selected texture shape,parameter analysis is conducted to determine the optimal combination for the above three parameters.Simultaneously,the simulated performances of radial lip seal with texture on the shaft surface are compared with those of the conventional lip seal without any texture on the shaft surface.