The reliability of most rotating equipment is almost inevitably linked directly to bearing life, and it is estimated bearing failure is responsible for almost 21% of these equipment failures (Bloch, 2011). Research into bearing failures (1) shows that just over half of these are a result of contamination of the bearing oil (Fig 1). Clearly it is therefore essential to ensure that contamination of the bearing lubricant is minimised and if possible eliminated if optimum bearing life is to be achieved thereby improving the equipment reliability (MTBF).
Prevention of bearing lubricant contamination can be provided by use of commercially available bearing isolators (or “bearing protectors”) however before applying such devices it is advisable that the user ensures that the protection device used does not itself adversely impact on the equipment reliability.
Here, Dr Chris Carmody [Special Products Manager] at AESSEAL explains how through the use of labyrinth design bearing protection seals, that bearing oil contamination can be eliminated. This is further demonstrated through the use of statistical modelling and analysis of field data such that a properly designed device will last at least as long as the theoretical life of the bearing it is protecting.