HEPPS - Electro-Mechanical Controllable Pitch Propeller/Fan/Turbine

A fan, propeller or turbine operated under varying speed is inefficient unless the pitch of the application’s blades is varied with changes in speed. We have developed a novel Electro-Mechanical Controllable Pitch fan (EMPC) which has applicability to HEPPS engine and hybrid electronic cooling. The advancement optimizes all dimensions of size, weight, power, cost and cooling (SWaP-C2). The disadvantages of hydraulic actuation have resulted in pitch control being ignored by VTOL propeller and small-to-medium cooling fan solutions. Our innovation will expand the technology’s practical utility into aerospace applications with the introduction of controllable-pitch fans for military use where energy utilization, particularly silent-watch demands, call for optimal efficiency.The major difference between electric and hydraulic actuation is efficiency. In controllable-pitch technology, an additional seal is introduced utilized by a hydraulic actuator in the pitch controller’s oil distribution box. Leaks can result in an efficiency reduction of up to 25%. Electric spindles have increasingly been replacing hydraulic pistons for linear actuation, resulting in significant increases in efficiency and performance. Pilot’s modernized strategy removes any mechanical coupling between the rotor and stator system by replacing hydraulic linear actuation with a modification of an electric spindle. In our design, the axial modulator (equivalent of the nut of an electric spindle) mates to the fan/propeller’s blade carousel via a ball screw; the linear motion of the axial modulator is translated to rotational motion in the blade through the interaction between the blade’s axis and a scotch yoke (“pitch manipulator”), which is mated to the axial modulator via a slew bearing, allowing the pitch manipulator’s rotation to be free from that of the axial modulator so that the pitch manipulator may remain in alignment with the fan carousel. The axial modulator has radial protrusions (in the style of a reluctance motor) whose edges can be detected by an inductive edge-detection sensor whose logic levels can be used to switch on electromagnets in the stator system to achieve pitch control. Pilot will create a hybrid-electric-propulsion cooling fan and instrument an air-flow test bench to address 4 key objectives:Demonstrate efficiency improvement vs incumbent technology across various operating profiles, measuring power draw and air flow;Implement a controls solution to mitigate any airflow impact related to cogging from reluctance effect;Minimize Noise and Vibration. The design employs a scotch yoke, slew bearing and ball screw. The latter two are known to eliminate backlash while the former may have some backlash inducing some vibration;Manage EMI levels. A gear-tooth sensor, measuring timing of electro-magnetic operation, and a linear displacement sensor, measuring displacement of the axial modulator, will be affixed to a post on the stator system.