ABSTRACT
For over 100 years, pitch control of marine and aeronautic propellers has been achieved by forcing hydraulic fluid into a rotating shaft. The inefficiencies and reliability concerns associated with this design can be addressed with this proposed electro-mechanical design employing the reluctance effect on a ferromagnetic “nut” mated to the thread on a fan’s rotating components. The mechanical advantage of the thread creates a transmission of sorts amplifying the torque produced on radial protrusions on the “nut” produced by switching current to electromagnets disposed in the stator system freeing the design from any mechanical coupling between the stator and rotor system. The design depicted within is in the prototype stage but is expected to produce improvements of efficiency by a factor of 2-3, doubling of mean-time-between failure, and a reduction of weight by 10%. The design is simple enough to make the technology practical for small to medium sized cooling fans and drones which have not enjoyed the benefits of controllable pitch technology.
