Electro-Magnetically Controlled Pitch Propeller/Fan/Turbine

Failing to adjust the pitch of a propeller, turbine, or fan when it is driven under varying speed is like driving down the highway stuck in first gear. For over a century, pitch control has been achieved by embedding a hydraulic piston into the rotating shaft/blade hub and then varying its linear position (ultimately translating to a change in blade pitch) by forcing hydraulic fluid into the rotating system through a complex seal. The inefficiencies of the seal are compounded by the inefficiencies of hydraulics, combining to create a heavy, maintenance-intense, and unreliable solution. This is so pointedly true that almost all fans on the market today are fixed pitch. Those attempting to electrify aircraft, like Uber Elevate, are entirely avoiding pitch control because of these challenges. Our solution removes the problematic aspects of hydraulics by leveraging electromagnetic actuation.

In the absence of pitch control, applications nevertheless seek the efficiencies of varied speed to maintain air flow at the lowest possible fan speed (i.e. power draw). Allan Bradley² found that this approach can draw as little as 1/8^th the power. Such large power savings beg the question, what could pitch control possibly add; a study³ from Wärtisilä suggests the answer – they changed an existing hydraulic controllable pitch solution to a more modern one (still hydraulic) and demonstrated that the modified ship could save 800 liters of fuel per sailing day while significantly reducing noise.