Polytetrafluoroethylene lubrication of radial rolling bearings: Control of lubricant transfer by cage design according to material-specific requirements

径向滚动轴承的聚四氟乙烯润滑：根据材料的具体要求，通过保持架设计控制润滑剂的输送

• 批准号: 407714666
• 负责人: Professor Dr.-Ing. Georg Jacobs
• 金额: --
• 依托单位: Fraunhofer-Institut für Werkstoffmechanik (IWM)
• 依托单位国家: 德国
• 项目类别: Priority Programmes
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/407714666?language=en
• 关键词: Polytetrafluoroethylene; lubrication; radial; rolling; bearings

Rolling bearings are used for guidance and power transmission between components under relative motion. For rolling bearings with solid lubrication, the formation and effect of transfer layers is important. Therefore, the cage or at least parts of the cage are made either from a solid lubricant or from a material doped with a solid lubricant in order to realize a film transfer from the cage to the bearing surfaces. The wear on the cage is determined by the load in the sliding contacts between the cage and the rolling elements. Until now, the operating life of solid-lubricated rolling bearings has been limited because the amount of material removed from the cage required for transfer layer deposition cannot be correctly adjusted. Insufficient lubrication due to insufficient transfer layer thicknesses in the rolling contacts and cage breakage due to excessive cage wear are typical damage patterns. In the first funding period, an experimental method was developed to determine the contact force in the sliding contact, which is required for the transfer in the sliding contact to lubricate a single rolling contact with pure PTFE. Thus, the determination of the operating point-dependent transfer layer generation is possible. However, due to the high wear rates of pure PTFE, the use of a composite such as PTFE/PEEK as a solid lubricant is required.The central hypothesis of the project is that the wear of the PTFE/PEEK reservoir at the cage can be reduced to a minimum value without deteriorating the lubrication effect. The aim of the project is therefore to determine the optimum composition of a PTFE/PEEK composite, considering the manufacturing and operating parameters (roughness, pressure, temperature, relative velocity). Another hypothesis is that the correct deposition rate of the transfer layer over the entire bearing lifetime requires a separation of transferred and guiding surfaces in the cage. Therefore, another goal is to design a bearing cage, in which the transferred and guiding surfaces are separated to allow an optimized lubricant transfer.Using a combination of MD simulations and tribometer measurements, the transfer, friction and wear processes of PEEK/PTFE composites are studied at the atomic level as well as at the single contact level. Parameter variations are used to determine the influences of the composition of the composite, the surface roughness of the contact partners and the operating conditions on friction and wear in sliding and rolling contacts. For a suitable combination of roughness and composition of the composite, the operating point-dependent material removal is determined. Based on this, the conceptual design, development and construction of a cage for radial roller bearings with integrated elements for PTFE/PEEK solid lubrication is carried out. Finally, functional verification is demonstrated in rolling bearing experiments.

滚动轴承用于相对运动部件之间的导向和动力传递。对于固体润滑的滚动轴承，传递层的形成和作用是很重要的。因此，保持架或保持架的至少一部分由固体润滑剂或由掺杂有固体润滑剂的材料制成，以便实现从保持架到轴承表面的膜转移。保持架上的磨损由保持架和滚动元件之间的滑动接触中的载荷确定。到目前为止，固体润滑滚动轴承的使用寿命一直受到限制，因为无法正确调整转移层沉积所需的从保持架上去除的材料量。由于滚动接触中的传递层厚度不足而导致的润滑不足和由于保持架过度磨损而导致的保持架断裂是典型的损坏模式。在第一个资助期内，开发了一种实验方法来确定滑动接触中的接触力，该接触力是滑动接触中的传递所需的，以用纯PTFE润滑单个滚动接触。因此，可以确定依赖于操作点的转移层生成。然而，由于纯PTFE的高磨损率，需要使用PTFE/PEEK等复合材料作为固体润滑剂。该项目的中心假设是，可以将椎间融合器处PTFE/PEEK储液器的磨损降低到最低值，而不会降低润滑效果。因此，该项目的目的是确定PTFE/PEEK复合材料的最佳组成，考虑制造和操作参数（粗糙度，压力，温度，相对速度）。另一个假设是，在整个轴承寿命期间，转移层的正确沉积速率需要保持架中转移表面和引导表面的分离。因此，另一个目标是设计一个轴承保持架，其中的转移和引导表面是分开的，以允许优化的润滑剂transfer.Using MD模拟和摩擦计测量相结合，PEEK/PTFE复合材料的转移，摩擦和磨损过程中，在原子水平以及在单接触水平上进行了研究。参数的变化是用来确定复合材料的组成，接触伙伴的表面粗糙度和操作条件上的摩擦和磨损的滑动和滚动接触的影响。对于一个合适的组合的粗糙度和组合物的复合材料，工作点相关的材料去除确定。在此基础上，进行了具有PTFE/PEEK固体润滑集成元件的径向滚子轴承保持架的概念设计、开发和构造。最后，在滚动轴承实验中进行了功能验证。