Transmission for a coaxial counter rotating rotor system

Abstract

A transmission system for a hybrid aircraft is driven by a plurality of driveshafts and drives a translational propulsion system. Each driveshaft is mounted to a pinion gear which mesh with an upper and lower counter-rotating gear. The upper and lower counter-rotating gears drive a respective upper and lower rotor shaft which powers a counter-rotating rotor system. A first angle is defined between a first and a second driveshaft while a second angle is defined between the second and a third driveshaft. The angle between the driveshafts are a whole number multiple of the formula: θ=(CP/R)*(180/π). By so angularly locating the driveshafts, proper meshing of the pinion gears and the upper and lower counter-rotating gears is assured and tolerances are less stringent as the support structure is effective designed around optimal location of the driveshafts for gear meshing rather than vice versa.

Dependencies are inferred from the claim text.