Lubrication

In the era of Industry 4.0, industrial asset management is seen as an important lever for improving the reliability and efficiency of production facilities. The promises of innovation associated with "connected" and "intelligent" sensor solutions almost lead us to lose sight of the real challenges of maintenance. In other words, it is about acting on symptoms to be proactive rather than tracking the initiation of a damage mode.

Maintenance excellence is based on several complementary pillars, between feedback, practical improvement needs in the field and the possibilities offered by technical and technological advances. In this context, lubrication management, particularly that associated with bearings, appears to be the Achilles heel of industrial equipment. However, the benefits of a Computer Aided Lubrication Management (CALM) programme are very real: reduction of maintenance costs, improvement of equipment availability, reduction of unplanned downtime, reduction of energy consumption, etc. Furthermore, in industry, the energy impact of electric motors is now the subject of a European directive (n°640/2009) requiring an increase in efficiency class. However, this eco-design effort must be coupled with an effective, long-term lubrication programme for motor bearings to make a real contribution to reducing energy consumption and CO2 emissions.

Known to the Egyptians and then formalised by L. De Vinci five centuries ago, the ball bearing has been mature since the beginning of the 20th century. Since then, it has become indispensable, without having had to evolve drastically. The bearing manufacturers have acquired a very good mastery of manufacturing (tribofinitions). At the same time, ever more effective lubricants have been developed to improve service life, reduce friction, dissipate heat, protect the facing surfaces, etc.

Today, more than 80% of bearings are now lubricated with grease (source: mogra), but it is often necessary to regularly top up with the right lubricant, in the right quantity and at the right time. The complexity of this task is the main cause of machine failures and experts estimate that around 60% of bearings do not reach their recommended fatigue life. Ideally, it is a question of maintaining an optimum amount of grease in the bearing that even tribology (the science of friction) cannot assess. In practice, greasing operations guided by empirical recommendations are poorly controlled, even with automatic grease nipples, and above all they are not objectified by measurement records. As a result, these strategic mechanical links are very often over- or under-lubricated, thus reducing reliability while penalising the energy efficiency of equipment. However, asset management based on "lubrication" provides concrete levers for improvement, based on human, organisational, technical and technological factors, which will be discussed during this workshop (see descriptions of the presentations). In particular, only ultrasonic-assisted lubrication allows the definition of lubrication plans adapted to each need or "thirst" of the bearing.