Rolls-Royce Ultrafan engine’s power gearbox breaks aerospace world record

The power gearbox for Rolls-Royce’s UltraFan engine has reached 87,000hp while under test in Germany, setting a new record for the world’s most powerful aerospace gearbox.

The gearbox reached 87,000hp (64MW), sufficient to power a small city was being tested at the Rolls-Royce facility in Dahlewitz, near Berlin. Engineers there are building the power gearbox (PGB) that will be delivered for integration into the UltraFan demonstrator engine, UF001, later this year.

UltraFan is a geared-turbofan engine that uses new materials and a variable pitch fan system that Rolls-Royce says enables improved fuel efficiency of up to 25% compared to the company’s first-generation Trent engine.

Ground testing of Ultrafan, which can be adapted for use on either narrowbody or widebody aircraft is expected to happen at Rolls-Royce’s Testbed 80 in Derby, UK next year, despite doubts about the level of future market demand for the engine because of Covid-19.

Dr Holger Klinger, sub-system executive power gearbox at Rolls-Royce said, “Reaching this record is another great achievement that showcases the performance and durability of this key component for our UltraFan programme. The power gearbox technology is central to the success of the next generation of Rolls-Royce jet engines and I’m proud to see us pushing the engineering boundaries again.”

The PGB has a central role for the UltraFan engine and has a planetary design, with each “planet” capable of holding the force of a Trent XWB engine at full throttle. It is designed to allow the turbine at the rear of the engine to run at a very high speed while the fan at the front runs at a lower speed to improve efficiency.

Development testing of the first prototype gearbox, focused on validation, endurance and reliability, began in 2017 at the dedicated PGB test facility in Dahlewitz. During a rigorous test regime, the power gearbox has since accumulated more than 650 testing hours.

As well as high power testing, the PGB has been undergoing test on the facility’s Attitude Rig, which simulates the effect of the gearbox being on the wing of an aircraft in flight, through phases such as take-off, climb, banking and descent.

Rolls-Royce has claimed the title of world’s most powerful aerospace gearbox before with the Ultrafan’s PGB in 2017. The PGB is designed to run all the way up to 100,000hp (74.5MW),