1st ICAI 2020

International Conference on Automotive Industry 2020

Mladá Boleslav, Czech Republic

A Development of Surface Acoustic Waves Based Method, for Lubrication Film Monitoring of Rolling Element Bearings Jakub Chmelař Independent researcher Úprkova 1578/5, Brno, 621 00 Czech Republic e-mail: jakubchmelar.cz@gmail.com Abstract Insufficient lubrication is a root cause of many sudden failures of tribological interfaces. Bearings are typical components where such failures occur. Unplanned service then leads to significant economical loses. Conventional method employed for their monitoring and failure prediction is vibrodiagnostics. It is capable to distinguish already initiating damage, but it is not efficient for detection of the lubrication related issues. This paper introduces a progressive method which uses processed signal of transfer characteristics of actively induced surface acoustic waves to detect changes in lubrication film with respect to operating conditions of bearings. Specifically, this paper describes set of tasks which lead to successful description of a method with high potential to extend real- time, in-situ assessment of lubrication film in rolling element bearings and therefore early detection of problems. Herein described tasks include description of numerical simulations of bearing and lubrication film, subsequent testing campaign and surface acoustic waves signal analysis with use of statistical methods. Keywords: bearings, lubrication film, monitoring, surface acoustic waves, JEL Classification: R49, Y20, Y80 1. Introduction Bearings are considered as the most critical components of the mechanical systems. Typical examples of their application in automotive industry are axle bearings allowing rotation of wheels, engine bearings supporting crank-shaft and gearbox bearings of individual gearbox-stages. To ensure reliable and maintenance-free operation, bearings need to be suitably lubricated. When this is not performed, sudden failure with serious consequences might occur. Industrial report (Schaeffler, 2010) states, that the major root-cause of bearing failure across various industries are problems with lubrication. 1.1 Limitation of Current Methods Majority of in-situ monitoring methods are based on observation of parameters signalising various levels of progressing degradation. Vibrodiagnosis is industry standard method. It is based on observation and evaluation of vibrations induced by bearings. With progressing severity of bearing damage, amount of emitted energy transmitted by vibration increases. Therefore, it can be detected as increasing acceleration of vibration at particular frequencies, specific for the bearing and application. Other method, frequently used in maintenance, is based on detection of resonant frequencies of bearing parts in ultra-sound spectra

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