Design and manufacturing of radial shafts seals mating surfaces using manufacturing processes with geometrically defined cutting edges - Diregeo

使用具有几何定义切削刃的制造工艺设计和制造径向轴密封件配合表面 - Diregeo

• 批准号: 430170022
• 负责人: Professor Dr.-Ing. Bernd Sauer
• 金额: --
• 依托单位: Lehrstuhl für Maschinenelemente und Getriebetechnik (MEGT)
• 依托单位国家: 德国
• 项目类别: Research Grants
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/430170022?language=en
• 关键词: Design; manufacturing; radial; shafts; seals

For the sealing of shafts in pressure-free areas or sections with minor pressure difference typically radial shafts seals (RSS) are applied. The specific design of RSSs leads to an axial carriage of the lubricant due to the shaft rotation, always directed in the direction of the oil storage. However, the surface microstructure of the mating seal surface (MSS) can result in a carriage effect as well, mainly attributed to a certain twist of the surface microstructure in turning. Surface macro-twist can be defined as a periodic, directional structure such as feed marks. In difference to that, micro-twist represents microstructures with its main direction providing a deviation of rectangularity with reference to work piece rotational axis. Consequently, the MSS are intended to be realized without twist; while up to date, no uniform thresholds are defined concerning macro- and micro-twist. Plunge grinding is typically considered as default process for finish machining of MSS, as typically hardened steels are applied. A predefined dressing and an adaption of the cutting process can typically reduce the twist. From an economical point of view, there are several disadvantages such as high investment, reduced flexibility, and due to comparably long spark-out, times reduced economic efficiency. The substitution of grinding by hard turning provides significant potential for cost reduction. However, up to date there is lack in a comprehensive understanding of the interactions between the process parameters, the surface microstructure, and the functional properties of the MSS. The end user information concerning the required surface specific values as well as information on the selection of tools and cutting parameters are limited. The aim of the proposed research is an in-depth understanding of the correlations between the process parameters in hard turning, the resulting surface microstructure of the MSS, and its functional properties in use. Accordingly, cutting experiments, bench tests, and computer aided process and elastohydrodynamic simulation (EHD) shall be applied. Another goal is the determination of the surface parameters for the function-related description of hard-turned MSS. For longitudinal turning, the influence of the macro-twist on the pumping rate and the friction torque should be examined by a variation of the cutting parameters and the tool corner geometry. Moreover, a predefined modification of the stochastic component of the roughness should be achieved by applying different cutting edge geometries and grain sizes of the CBN cutting material taking the tool wear into consideration. The findings should be used for the qualification of the start-stop-turning (SST), a special process for the machining of MSS. In this context, SSD represent a turning process enabling the generation of MSSs characterized by a zero lead angle, which already provided comparably low pumping ratios in preliminary investigations.

为了密封无压力区域或较小压力差的切片，通常会施加径向轴密封（RSS）。 RSS的特定设计导致由于轴旋转而导致润滑剂的轴向载体，始终朝油存储方向。但是，交配密封表面（MSS）的表面微观结构也可能导致托架效应，这主要归因于转弯时表面微观结构的某种扭曲。表面宏扭动可以定义为周期性的定向结构，例如进料标记。在与此不同的情况下，微扭曲代表其主要方向的微观结构，该微观结构在参考工件旋转轴的情况下提供了矩形的偏差。因此，MSS旨在实现而无需扭曲。在最新的情况下，没有定义有关宏观和微扭曲的均匀阈值。通常认为插入磨削是MSS完成加工的默认过程，因为通常应用了硬化的钢。预定义的敷料和切割过程的适应性通常可以减少扭曲。从经济的角度来看，有几个缺点，例如高投资，灵活性降低，并且由于相当长的火花，经济效率降低了。用力转弯替换磨削为降低成本提供了巨大的潜力。但是，最新的是，缺乏对过程参数，表面微观结构和MSS功能属性之间相互作用的全面理解。有关所需表面特定值以及有关选择工具和切割参数的信息的最终用户信息受到限制。拟议的研究的目的是深入了解硬转动过程中的过程参数之间的相关性，MSS的结果表面微观结构及其使用的功能性能。因此，应应用切割实验，基准测试和计算机辅助过程和弹性水力动力模拟（EHD）。另一个目标是确定与函数相关的型MSS描述的表面参数。对于纵向转弯，应通过切割参数的变化和工具角几何形状来检查宏扭扭扭矩和摩擦扭矩的影响。此外，应考虑工具磨损的CBN切割材料的不同尖端几何形状和晶粒尺寸来实现粗糙度的随机分量的预定义修饰。这些发现应用于开始停滞不前（SST）的资格，这是MSS加工的特殊过程。在这种情况下，SSD代表了一个转弯过程，使得以零铅角为特征的MSS产生，在初步研究中已经提供了相当低的泵浦比率。