HEROe Bearing · Project

Lighter, Longer-Lasting Ceramic Bearings for Helicopter Gearboxes Ready for Production

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Helicopter gearboxes spin at extreme speeds and need bearings that can take a beating — literally. Traditional steel bearings wear out, add weight, and fail when oil runs low. NTN-SNR took ceramic rollers (silicon nitride, the same tough material used in cutting tools) and combined them with steel rings to make hybrid tapered roller bearings. They tested these under harsh conditions — contamination, poor lubrication, even total oil cutoff — and compared them head-to-head against standard steel bearings to prove the ceramic ones last longer and weigh less.

By the numbers

test conditions validated (clean, contaminated, poor lubrication, oil shut-off, defect)

consortium partner — sole industry developer (NTN-SNR)

100%

industry participation ratio in consortium

total project deliverables

The business problem

What needed solving

Helicopter gearbox bearings face extreme conditions — contamination, poor lubrication, and occasional oil supply interruptions. Standard steel bearings degrade faster under these conditions, leading to shorter service intervals, higher maintenance costs, and added weight that reduces payload capacity. Operators and OEMs need bearings that last longer, weigh less, and survive harsh operating environments without compromising safety.

The solution

What was built

The project produced Si3N4 ceramic roller bearing demonstrators for helicopter gearbox applications. These hybrid tapered roller bearings were manufactured, tested under five operating conditions (clean, contaminated, poor lubrication, oil shut-off, and with roller defects), and validated against steel bearings in back-to-back comparison. Updated design rules and simulation tools for hybrid bearings were also delivered.

Audience

Who needs this

Helicopter fleet operators needing longer maintenance intervalsRotorcraft gearbox OEMs designing next-generation transmissionsAerospace MRO providers servicing helicopter drivetrainsSi3N4 ceramic component manufacturers seeking aerospace qualification partnersDefense procurement agencies specifying helicopter powertrains

Business applications

Who can put this to work

Aerospace MRO & Helicopter Operators

enterprise

Target: Helicopter fleet operators and MRO service providers

If you are a helicopter operator or MRO provider dealing with frequent gearbox bearing replacements and maintenance downtime — this project developed hybrid ceramic-steel tapered roller bearings that demonstrated improved life duration and better performance under contaminated and poor lubrication conditions. Longer-lasting bearings mean fewer unscheduled maintenance events and more flight hours between overhauls. NTN-SNR tested these bearings back-to-back against steel under oil shut-off and contamination scenarios.

Aerospace Gearbox & Transmission Manufacturing

enterprise

Target: Helicopter and rotorcraft gearbox OEMs

If you are a gearbox manufacturer looking to reduce weight and improve reliability in next-generation rotorcraft transmissions — this project produced Si3N4 ceramic roller bearing demonstrators specifically designed for helicopter gearbox applications. The project defined critical defect parameters for mass production and updated design rules for hybrid bearing integration. This gives you a validated component ready for qualification in your transmission systems.

Industrial Bearing & Precision Components

mid-size

Target: Bearing distributors and specialty component suppliers serving aerospace

If you are a precision component supplier looking to expand into high-value aerospace bearing markets — NTN-SNR developed and validated hybrid tapered roller bearing technology with ceramic rollers, including updated design handbooks and simulation tools. The project established manufacturing processes and critical defect criteria needed to move from prototype to aerospace mass production, creating supply chain opportunities for Si3N4 roller manufacturing and inspection.

Frequently asked

Quick answers

What would hybrid ceramic bearings cost compared to standard steel bearings?

The project data does not include specific pricing. Ceramic (Si3N4) rollers are generally more expensive than steel, but the cost case rests on longer bearing life and reduced maintenance frequency. A total cost of ownership analysis would need to factor in fewer replacements and less unscheduled downtime.

Are these bearings ready for industrial-scale production?

The project specifically addressed mass production readiness by defining critical defect sizes, shapes, and locations on rolling elements. NTN-SNR updated their design handbook and simulation tools for hybrid bearings. Based on available project data, the technology is at demonstrator stage with manufacturing parameters established for scaling up.

Who owns the intellectual property and can I license this technology?

NTN-SNR ROULEMENTS SA is the sole consortium partner and likely holds the IP. As a major existing supplier for European helicopter gearbox bearings, they would be the contact point for licensing or supply agreements. The project was funded under Clean Sky 2, which may have specific IP arrangements with the topic leader.

Has this been tested under realistic operating conditions?

Yes. The project performed back-to-back testing under five conditions: clean environment, contaminated conditions, poor lubrication, oil shut-off, and tests with deliberate roller defects. These simulate real-world failure scenarios that helicopter gearbox bearings face in service.

What is the timeline from current status to flight-certified bearings?

The project closed in August 2021 with demonstrator bearings manufactured and tested. Moving to flight certification would require qualification testing per aerospace standards (e.g., DO-160, OEM-specific requirements). Based on available project data, the exact certification timeline is not specified but the manufacturing and testing groundwork is complete.

Does this only apply to helicopters or could it work in other applications?

The project focused specifically on helicopter gearbox tapered roller bearings, but the hybrid ceramic-steel bearing technology and the design rules developed could apply to other high-performance rotating machinery. Any application where weight savings, extended bearing life, or resilience to poor lubrication matters could potentially benefit.

Consortium

Who built it

This is a single-company project: NTN-SNR ROULEMENTS SA from France, a major established supplier of helicopter gearbox bearings in Europe. With 100% industry participation and zero academic partners, the project is entirely commercially driven. NTN-SNR brought existing manufacturing capability, customer relationships, and deep domain expertise in aerospace bearings. The absence of university partners means all IP stays with one company, simplifying licensing discussions. The Clean Sky 2 framework means there is a topic leader (likely an airframer like Airbus Helicopters) who defined the requirements, giving this strong pull from an end customer.

How to reach the team

NTN-SNR ROULEMENTS SA, France — major European aerospace bearing supplier. Contact their aerospace division or business development team.

Order a report on this consortium

Next steps

Talk to the team behind this work.

SciTransfer can connect you with the NTN-SNR team to discuss hybrid bearing supply, licensing, or integration into your gearbox systems. We handle the introduction so you get a direct line to the engineers who built and tested these bearings.

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