Case Study: How GMN Bearings Helped Extend the Life of a Ram Air Turbine

A large U.S.-based electric motor manufacturer came to us when their Ram Air Turbine (RAT) gearbox, meant to provide emergency backup power on an aircraft when other systems fail, wasn’t holding up. Gears and bearings were failing in multiple places, and test after test ended in breakdowns. The clock was ticking, and they needed a solution they could count on.

That’s where GMN stepped in. Our engineers dug deep into the gearbox design, ran all the necessary calculations, pinpointed the weak spots, and helped turn things around. Fast-forward to today: the gearbox is still going strong, exceeding its expected lifespan, and delivering the kind of reliability you need where it matters most.

What is a Ram Air Turbine (RAT)?

A Ram Air Turbine (RAT) is a backup power source that deploys mid-air and uses wind to power a generator and keep essential aircraft systems running if the main power is lost. It’s built for high-stakes situations and one of those applications that has to work, even though you hope it never needs to.

The Challenge

Our OEM’s RAT gearbox wasn’t working as expected. Bearings and gears were wearing out fast, well before expected life requirements. During testing, parts were failing under load, and confidence in the design was fading quickly.

Internally, their team felt stuck. They knew something had to change but weren’t sure where to begin. With the success of the project and the safety of future aircraft at stake, they turned to GMN for a solution.

How GMN Helped

GMN engineers rolled up their sleeves and got to work; not just tossing out recommendations, but backing up everything with real data and working closely with their team to get things moving in the right direction:

• Performed in-depth bearing life calculations
• Ran tolerance and thermal analysis
• Re-evaluated RPM and load specs for real-world conditions
• Inspected failed parts and provided full engineering reports
• Partnered with their team through every stage of the redesign and testing

We provided multiple hybrid radial ball bearings that could handle the heavy vibrations, dual direction axial load, and extreme possible running conditions.

The goal wasn’t just to patch the issue; it was to get to the root of it and build a better-performing system from the inside out.

The Results

With the help of GMN bearings in their system, the updated gearbox design cleared testing, exceeded the OEM’s reliability targets, and is now in production. It’s performing better than expected and proving to be a long-term solution our customer can count on. Their team has confidence and peace of mind knowing the gearbox is ready for flight, ready for emergencies, and ready to do its job without hesitation.

Why It Worked

GMN engineers looked at the full picture: materials, tolerances, duty cycles, thermal effects, and beyond. Our level of technical expertise helped reshape the gearbox design and turn a high-risk weak spot into a high-reliability component.

And by doing that, we didn’t just fix a bearing problem. We helped extend the life of the entire gearbox and gave the OEM a product they could finally trust.

Lets Talk!

When you’re working on systems that have to perform, especially in aerospace, you need more than parts. GMN Bearing USA engineers and technical experts are here to help.

Not sure if your bearing setup is right or need help with troubleshooting? Give us a call and we’ll help you sort it out!

Contact a GMN Bearing USA engineer