Increased rolling strength and friction reduction for bearings and homokinetic joints due to innovative hard machining

疲劳寿命和摩擦条件是轴承部件使用过程中的限制因素。这些因素受接触区域的表面完整性、性质、残余应力和表面形貌以及主要应力的影响。该应用程序的目标是通过创新的硬加工工艺为轴承和同动关节设计和创建最佳的表面完整性状态。必要的表面完整性将由可靠和经济的工艺来实现。由于对滚子轴承和同动关节进行了分析，在此应用中考虑了摩擦学状态、全润滑和混合摩擦。在第一个应用中，重点放在滚子轴承上。由于硬车削和深轧的过程会产生必要的残余应力和表面形貌，尽管这些过程必须相互调整。对于表面粗糙度很低的情况，深滚压会导致表面质量恶化。创建的计算轴承寿命的模型可以考虑残余应力的前提条件，并显示出寿命的提高。为了分析同质连接中混合摩擦的影响，将在这一阶段结束时确定铣削工艺参数对表面完整性的显著影响。以下应用程序将增加这方面的知识。针对滚子轴承经济可靠的硬调深、车滚压相结合的工艺，分析其对表面完整性的影响。所创建的完全润滑模型将在轴承的静态寿命测试中进行验证。对于均质连接，将考察铣削工艺和刃口几何尺寸对表面完整性、残余应力和表面形貌的影响。最后从摩擦学条件和寿命两个方面分析了不同的表面形貌和残余应力状态对摩擦副性能的影响。结果表明，完全润滑的模型可以转移到混合摩擦区。

The fatigue life time and the friction conditions are limiting factors during the operation of bearing components. These factors are many influenced by the surface integrity properties residual stresses and surface topography within the contact area and the prevailed stresses. The goal of this application is to desgin and create an optimal surface integrity state for bearings and homokinetic joints by an innovative hard machining process. The necessary surface integrity will be induced by reliable and finacial processes. Due to analyzing roller bearings and homokinetic joints the tribologiy states full lubrication and mixed friction are considered in this application. In the first application periode the focus stays on the roller bearings. Due to the processes hard turning and deep rolling the necessary residual stresses and surface topography can be created, altough the processes have to be adjusted to each other. For a very low surface roughness, the deep rolling can cause a deterioation of the surface quality. A created model to calculate the lifetime of bearings can consider the preconditions due to residual stresses and shows an improvement of the lifetime. To analyse the effects for the mixed friction in homocinetic joints, the significant to affect the surface integrity due to process parameters for the milling will be determined at the end of this period. The following application will increase this knowledge. For the roller bearing a financial and reliable process combination of hard truning and deep rolling, turn-rolling, and its effects on the surface integrity will be analyzed. The created models for the full lubrication will be verfied in statitical lifetime tests of the bearings. For the homocinetic joints the influence of the milling process and cutting edge geomtry on the surface integrity, residual stresses and topography, are going to be examined. Finally the effect of the different topography an residual stress state will be analyzed in means of the tribology conditions and lifetime. The results will show, that the models for the full lubrication can be tranfered to the mixed friction area.