Spherical plain bearings are equipped with a predictive maintenance system

Discussing how this might work in practice, igus gives the example of a maintenance technician working on, say, a conveyor belt in a bottling factory. His phone app notifies him that a flange bearing is approaching its wear limit.

While previously there was a risk that this would go undetected and lead to an expensive system failure, today the technician can spot the issue and replace the bearing during the production break.

This scenario is no longer science fiction. As part of our smart plastics range, we are gradually equipping plain bearings made of high-performance plastic with networked sensors, says Rob Dumayne, dry-tech director at igus. Our two- and four-hole flange bearings of the igubal series can now also enable condition monitoring and predictive maintenance so as to avoid unforeseen damage.

igus integrates an abrasion sensor into the polymer spherical bearing, a thin circuit board, plus a battery for power supply without cables. This allows the bearing to continue to move freely for spherical compensation. As the bearing wears, the traces of the board are interrupted. When the electronics lose the signal of a trace, they know that the wear has reached a certain level.

The sensor emits a digital signal over a Long Range Network (LoRa), a wireless standard for the Internet of Things that is known for its energy efficiency. This is received by the i.Cee control cabinet module, which now takes over the data evaluation. The smart bearing software now knows that the trace is worn out and calculates the percentage of abrasion.

Over time, the sensor wears out layer by layer, parallel to the running surface of the bearing. And it regularly emits signals that allows the control to work out the bearings condition. Users can see the remaining service life and when a maintenance call is due on a web-based dashboard, that they can see the bearings status from anywhere in the world with a PC, tablet or smartphone.

First pilot customer

The new flange bearings are in the prototype phase, and they have already convinced one pilot customer: the Socit National des Chemins de Fer Luxembourgeois (CFL).

Luxembourgs state-owned railway company operates a 200-metre-long car wash that cleans local and long-distance trains every day. In the past, gearbox malfunctions in the wash wagon repeatedly led to costly system failures. For this reason, CFL has abandoned lubricated standard ball bearings and instead installed the cross-linked spherical bearings from igus in the UC bearing housings.

These high-performance, spherical bearings are corrosion-free, chemical-resistant and, with integrated solid lubricants, enable low-friction and maintenance-free dry running. The other bearings need to be lubricated every few weeks, which is time-consuming, says CFL maintenance manager, Mike Feinen. So weve now ticked off this maintenance snag.

Rob Dumayne adds: The networking of these smart bearings is the icing on the cake. Thanks to continuous condition monitoring, CFL can prevent failures, plan maintenance interventions and make full use of the service life of the polymer bearings.