Rolls-Royce reported its ongoing technology testing for its new generation of geared turbofan engines has resulted in a new record for “the world’s most powerful aerospace gearbox.” Chief technology officer Paul Stein announced at an aerospace technology conference in Great Britain that, just a few months into testing of the Power Gearbox at Rolls-Royce’s gearbox development center in Dahlewitz, Germany, the new unit had successfully reached 70,000 horsepower.
Rolls-Royce’s Power Gearbox is designed to run at up to 100,000 HP, and future demonstrator units are expected to achieve these levels, it stated.
“Setting this record is a great achievement for the team and I’m proud we’ve managed to get there so quickly,” Stein stated at the International Society for Air Breathing Engines (ISABE) conference in Manchester, England. “Our Power Gearbox technology is central to the success of the next generation of Rolls-Royce jet engines and I’m pleased to see us pushing back engineering boundaries with this work.”
The Power Gearbox will be featured in Rolls’ new UltraFan engine, announced in 2014 along with another new engine, called the Advance. The latter is an improved version of the current Rolls-Royce Trent engine, high-bypass turbofan technology, and due to make a commercial debut in 2020.
The UltraFan will incorporate the emerging “geared turbofan” engine technology, which is considered to be more energy efficient as it allows the compressor-turbine assembly and the fan to spin at different angular velocities. Rolls has stated the UltraFan will provide at least 25% better fuel-efficiency than the first-generation of Trent engines, with lower carbon emissions levels for commercial aircraft operators. It aims for the UltraFan to come to market in 2025,
The Power Gearbox 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 shafts at the core of the engine to run at very high speeds, while the fan at the front of the engine runs at slower speeds. The greater efficiency and weight reduction that is accomplished in this way are expected to allow the UltraFan engine to offer the improved fuel efficiency.
Testing of the first demonstrator gearbox began on a specifically designed rig in May, according to the engine builder. Having proven its high-horsepower potential (“the equivalent power of around 400 family cars at full throttle,” Rolls claimed) the testing next will focus on lower power functions, such as endurance and reliability.
The Power Gearbox is also undergoing Attitude Rig testing, 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 is working with its joint-venture partner Liebherr-Aerospace to develop manufacturing capability and capacity for the new Power Gearbox. Rolls-Royce leads the design definition and design integration of the project, as well as testing activities.