SKF (www.skf.com) makes bearings for things that move around, from cars to combines. They also make them for things that move around while stationary—both on land and at sea—namely, wind turbines.

A problem for the growing number of turbines dotting the landscape is maintaining their planetary gearboxes, many of which have succumbed to failures over the years, especially as units installed in the 1990s start to reach the end of their life. At the same time, component makers like SKF face the challenge of a shrinking product development cycle. The 3- to 5-year cycle of just a few years ago has decreased to 1 to 2 years or less, while the customization of the parts needed is only increasing.

“It’s starting to become much more like the aerospace industry, where no longer do you want to just offer a catalogue-type solution, but something designed specifically for that application,” says Greg Zimmerman, SKF manager-platform integration and engineering consulting services, which means he heads up a team using specialized tools for virtual product development. “What we’re looking for from a modeling perspective is bringing that real-time field data back into the lab to then say ‘Ok, the gearbox is designed for this amount of load, but it’s really seeing this much. What does that mean for that component’s life and performance?’”

Enter WindCon, a condition measurement system SKF created to monitor component performance and predict maintenance needs. It monitors factors including lubrication, electrical consumption and output, wind inputs, blade balance and alignment, gears, and of course, bearings. It relays data from four or five in the gearbox to a WiFi-enabled module that directs it to a server and then to the Web enabled monitoring tool.

Recently, the system was adopted by product developers in the lab to design new components. The process starts with a gearbox supplier sending a design to SKF, usually created in Pro/ENGINEER or SolidWorks, of the gearbox housing or other components in contact with the bearings. SKF will take that design, add in its own bearing CAD blueprint and run simulations with the company’s Orpheus tool. Normally, such a test would be largely theoretical, but the element of reality is introduced when the field load data and WindCon condition data is imported into it. As it runs the simulation, or sometimes thousands of them, designers look to see if, for example, the planetary gears start to deform, or “ovalize” from wear and tear, and what that does to the bearings.

The process of virtual product development helped the company more quickly introduce a new type of a cylindrical roller, dubbed “E2,” in two years compared with the expected three. The bearings are 30% more energy efficient thanks to less friction and rolling resistance than the standard bearings and are significantly lighter, according to SKF.

This is important because turbine manufacturers are increasingly trying to maximize megawatts from their windmills, while reducing the space and weight available for the gearbox. Gearbox manufacturers are being asked by major turbine OEMS to take up to 20% of the weight out of things like planetary carriers, for instance, Zimmerman says. “To design a bearing for that, we have to find out what that’s going do to our bearing from a system perspective,” he notes. “And maybe it does nothing to fatigue life prediction, but it can cause a system issue such as misalignment that is difficult to predict with traditional catalog methods. And we can now with much more certainty predict potential failure modes using advanced simulation tools such as SKF Orpheus.”