铣齿机主轴箱均载机构的设计与分析

铣齿机主轴箱采用双排齿轮系统传递扭矩,由于齿轮存在制造及装配误差,导致主轴箱两排齿轮受力不均.根据机床主轴箱功率分流传动的特性,设计了主轴箱均载机构.介绍了均载机构的结构及工作原理,采用电液比例控制方式设计了均载机构液压系统.通过对均载机构工作时的负载力分析确定了均栽机构控制策略,研究了系统的工作状况.     

基于NURBS的齿轮盘铣刀后刀面插补点计算

将NURBS曲线方法应用于盘铣刀后刀面插补中,通过盘铣刀后刀面上给出的一些数据点,首先反算出盘铣刀后刀面的数据点曲线的控制顶点,再根据德布尔算法求得该曲线上的点,进而找到所要求的插补点,并拟合出了插补曲线;最后给出了该算法的应用实例。     

Research of Stamp Forming Simulation Based on Finite Element Method

We point out that the finite element method offers a great functional improvement for analyzing the stamp forming process of an automobile panel. Using the finite element theory and the simulation method of sheet stamping forming, the element model of sheet forming is built based on software HyperMesh,and the simulation of the product′s sheet forming process is analyzed based on software Dynaform. A series of simulation results are obtained. It is clear that the simulation results from the theoretical basis...     

On the real singularities points of cycloids,epi- and hypocycloids

This work considers the continuous transition between singular points of cycloids with help of complex parameters.     

Preparation and alkaline stability of polyethylene composite hydroxide exchange membranes with different cations

Hydroxide exchange membrane fuel cells (HEMFCs) are a cost-effective alternative to proton exchange membrane fuel cells due to the advantages on fast oxygen reduction reaction kinetics, low cost and weak corrosion. Hydroxide exchange membrane (HEM) is the core component for HEMFC. At present, lacking highly robust and chemically stable HEMs is the main challenge to realizing durable HEMFCs. Polyethylene composite HEMs are considered as the-state-of-the-art HEM candidates due to their excellent mechanical properties, thus allowing for the use of ultrathin HEMs in HEMFCs to achieve a high cell and stack performance. Yet, the chemical stability of polyethylene composite HEM still needs to be improved for more durable HEMFC. In this study, we report that the preparation and chemical stability understanding of three polyethylene composite HEMs (named AEH-TMA, AEH-DMP and AEH-TMI) functionalized with trimethylamine (TMA), N-methylpiperidine (DMP) and 1, 2, 4, 5-tetramethylimidazole (TMI), respectively. We find that AEH-TMI exhibits a low conductivity and inferior chemical stability in comparison to AEH-TMA and AEH-DMP. To gain insight into chemical stability behavior, we have also prepared three organic chemicals (named Bn-TMA, Bn-DMP and Bn-TMI) as cations model by reacting benzyl chloride with TMA, DMP and TMI cations and elaborately studied their chemical stability in various water content systems. The results show that the overall chemical stability of cations can be strongly improved with increasing the surrounding water, and Bn-TMI suggests a lower chemical stability than Bn-TMA and Bn-DMP at high water content condition.