Operating condition-dependent model for describing the electrical impedance of rolling bearings for sensory utilization

研究现状表明，滚动轴承电容的相关影响因素取决于运行工况，忽略了这些影响因素。载荷区外的滚动接触对滚动轴承的阻抗有影响，有助于改善载荷与阻抗之间的模型相关性。为了描述无载荷滚动元件的阻抗，采用了与工况相关的几何形状的一般弯曲电容器模型，该模型对应于球与内环或外环之间的点接触。本文提出了以下工作假设：1、卸载滚动体的分离润滑膜影响滚动轴承的电容；卸载滚动体上的润滑膜厚度、轴承间隙和滚动体密度必须进入电容。WH II。边界因素可以被一个依赖于运行参数的物理激励模型所取代，以描述无经验因素的点接触滚动轴承的实测阻抗。在申请的项目中，通过考虑点接触滚动轴承在任意载荷角度下阻抗模型中的卸载滚动单元，将测量与计算之间的差异减小到足以用于感官概念的水平。这导致了以下项目目标：描述载荷区外滚动体的载荷相关位置和运动学，用于计算卸载滚动接触的能力。所有滚动触点的完整阻抗贡献的映射。在相关工作范围内对不同的点接触滚动轴承进行扩展试验的验证。研究混合摩擦对了解滚动轴承的电行为也是必要的。对小测量电压的限制是必要的，以避免不必要的电流通过和损坏滚动轴承或润滑剂。然而，重点是滚动轴承的流体动力运行，并随机研究了尺寸对第二尺寸的影响。由于污染或老化导致的润滑剂变化被排除在外，滚动轴承的损坏也被排除在外。定期过滤和更换润滑油。在短期试验中对滚动轴承进行了检查，并进行了一些初步试验，以确定滚动轴承可以在不改变的情况下进行检查的累积损伤的计算上限。在该项目中，考虑了具有点接触的单列滚动轴承，主要在EHD条件下静止，但也在混合摩擦中。由于滚动接触过滚期间的非常短的时间事件，调查结果也可以转移到具有变速加载的滚动轴承。

The state of research shows that relevant influencing factors of the electrical capacitance of a rolling bearing, which depends on the operating condition, are neglected. The rolling contacts outside the load zone have an influence on the impedance of the rolling bearing and contribute to an improvement of the model correlation between load and impedance. To describe the impedance of unloaded rolling elements, the model of a generally curved capacitor with operating condition-dependent geometry corresponding to the point contact between ball and inner or outer ring is used. The objectives motivate the following working hypotheses:WH I. The separating lubricating films of unloaded rolling elements affect the electrical capacitance of rolling bearings; lubricating film thickness on unloaded rolling elements, bearing clearance, and the density of rolling elements must enter into the capacitance.WH II. The boundary factors can be replaced by an operating parameter-dependent physically motivated model to describe the measured impedances of rolling bearings with point contact without empirical factors.In the project applied for, the difference between measurement and calculation is to be reduced to a level sufficient for a sensory concept by considering the unloaded rolling elements in the impedance model at arbitrary load angles for rolling bearings with point contact. This results in the following project objectives:1. description of the load-dependent position and kinematics of the rolling elements outside the load zone for calculation of the capacity of the unloaded rolling contact.2. mapping of the complete impedance contribution of all rolling contacts.3. validation of the extensions in tests on different rolling bearings with point contact in the relevant operating range.Investigations also in mixed friction are necessary to understand the electrical behavior of rolling bearings. The limitation to small measuring voltages is necessary to avoid unwanted current passage and damage to rolling bearings or lubricant. However, the focus is on the hydrodynamic operation of rolling bearings, and the influence of size is investigated randomly on a second size.Changes in the lubricant due to contamination or aging are excluded, as is damage to the rolling bearing. The lubricant is filtered and replaced regularly. The rolling bearings are examined in short-term tests, and a few preliminary tests are also carried out to determine a calculated upper limit for the accumulated damage up to which the rolling bearings can be examined without alteration. In the project, single-row rolling bearings with point contact are considered, primarily stationary at EHD conditions but also in mixed friction. Due to the very short-time events during the overrolling of a rolling contact, the findings from the investigation can also be transferred to rolling bearings with variable-speed loading.