Remote condition monitoring of slewing bearings on open sea

What were the beginnings of the development of condition monitoring systems at thyssenkrupp rothe erde?

Gideon Eichner: Condition monitoring for thyssenkrupp rothe erde started back in the 1980s. At that time, this was a topic in the field of offshore cranes. There were, and still are, strict requirements imposed by the DNVGL (international classification society for engineering services and technologies) to ensure the safety of these installations. If there is no other possibility to inspect the bearing accordingly, the slewing bearing must be opened and the raceway inspected for damage to this day.

This means an enormous effort for our customers. At the time, our colleagues considered how thyssenkrupp rothe erde could meet this challenge. The solution is our certified ECMS^® system. With the ECMS^® we can offer our customers an optimized condition check without dismantling and opening the bearing. The added value for our customers are more predictable maintenance intervals and higher plant availability with the same maximum safety.

You mentioned ECMS^® – what exactly does it stand for?

Gideon Eichner: ECMS^® is the abbreviation for the Eddie Current Measurement System. You could say that it is an electrical method using eddy current for contactless materials testing. In our case, the system is an element equipped with sensors that run inactive in the slewing bearing during regular operation. If an examination is to be carried out, a service employee triggers the sensor system and data transmission in a round trip utilizing an external energy feed.

The ECMS^® can then examine the raceways and transition radii for possible damage, such as wear, pittings, and cracks. Depending on the configuration, various data can then be obtained, which, after analysis by thyssenkrupp rothe erde, provides information on the slewing bearing condition. The analog system is now being updated to meet the requirements of the digital age.

They work on the further development of the system. What can we expect from thyssenkrupp rothe erde in this area in the future?

Dr. Gunther Elfert: In addition to the ECMS system, we have been offering the Integrated Wear Measurement System (IWM) for years, another proven system for monitoring slewing bearings. The IWM system has also been fundamentally revised. In addition to a digital platform, it has also been given a new name: rothe erde^® Integrated Condition Monitoring or ICM^® for short.

The ICM^® system can use various sensors to record, for example, bearing wear, the motion profile, temperatures, etc., and analyze them locally in real-time. Besides, the data can be made available via various interfaces such as WLAN or Bluetooth. In this way, the customer can be informed in good time of any maintenance or inspection of the bearing that is due.

A further development is the rothe erde^® Smart Roller. This is a roller equipped with measuring technology integrated into the rolling element chain and sends, for example, direct load data and load distributions from a continuously rotating bearing.

In general, the further development of our solutions in condition monitoring is very much driven by the topics of digitalization and Industry 4.0, which open up new possibilities for us from the development of intelligent bearings to networked, cloud-based systems for continuous condition monitoring of slewing bearings.

Our cloud-based CMS solution offers the advantage that our customers worldwide can access the data at any time. A smart bearing concept, comparable to the smart home concept. Via a cockpit, the customer can inform himself about all his warehouses’ status, whether from the office or his sofa at home. In addition, we offer our customers comprehensive analyses, reporting, and other services.

What are the application areas for these systems?

Gideon Eichner: One example is offshore wind turbines. The operator of offshore wind farms would prefer not to go out to sea every time to monitor individual components’ condition in his turbines. This is already happening from a distance today, thanks to very intelligent monitoring technology. This is where the rothe erde^® Smart Roller technology fits in seamlessly and thus offers the possibility of monitoring an essential component with the main bearing of the wind turbine.

Another application of our ICM^® system is mining technology, e.g., a large excavator in mines. In addition to position measurement, it is essential for the operator to know the current condition of the slewing bearing and to be able to use his machine optimally.

In the past, products in the wind industry were put through their paces on test rigs over several months, sometimes even years. With the rothe erde^® Smart Roller, we can significantly shorten the development of a new bearing for our wind customers. In addition, we can use the data obtained to support our complex calculations for the bearing design and back them up with real values. This creates trust with our customers!