Rolls-Royce set a new record for most powerful aircraft engine gearbox on Monday, as its Power Gearbox (PGB) intended for the upcoming UltraFan engine reached 70,000 horsepower on a test rig Rolls-Royce’s facility in Dahlewitz, Germany. Ultimately, Rolls-Royce intends for the gearbox to hit 100,000 horsepower, equivalent to about 100 Formula 1 cars combined.
Rolls-Royce started testing its Power Gearbox late last year, and the company plans to use the PGB to build its geared UltraFan engine, which, on paper, will be 25 percent more fuel efficient than the manufacturer’s current line of Trent engines. Geared turbofans are aircraft engines with a gearbox between the fan and the turbine assembly, allowing the two components to rotate at different velocities. By operating at different gear ratios, a geared turbofan can maintain higher efficiency during different parts of flight, such as takeoff and cruise.
The PGB is what is known as a “planetary” gearbox, with multiple gears rotating around a central component. Each individual gear planet is capable of holding the force of a Trent XWB engine at full throttle. The configuration will allow the shafts in the core of the engine to rotate at a higher speed than the fan itself.
The UltraFan is Rolls-Royce’s next-generation aircraft engine with a geared configuration as well as composite materials, including carbon-titanium fan blades, to maximize fuel efficiency. The engine will be considered for a number of new Boeing and Airbus designs, and Boeing has indicated that it is looking for a geared turbofan specifically for its next airliner, possibly to be called the Boeing 797.
Ongoing Power Gearbox tests will bring the system up to 100,000 horsepower, and the PGB is also going through attitude rig tests that simulate different parts of flight. Rolls hopes to have the UltraFan completed and ready for commercial flight service by 2025.