STUDY OF THE TRANSMISSION IN HELICOPTERS FROM THE MAIN ROTOR TO THE TAIL

This thesis aims to investigate the power transmission from the engines of a helicopter to the tail rotor. The tail rotor is an essential component for the proper control of a helicopter. Even though different methods for the control of such vehicles have been developed, the tail rotor remains the principal solution for most helicopter types. In general, the power transmission requires two gearboxes which allow translation in the direction of power coming from the main gearbox to the tail rotor, which is at a ninety-degree angle and possibly at a higher level with respect to driveshaft coming from the engines, as well as a speed reduction. The main objective of this paper is firstly the study of the layout and assembly of the drivetrain layout and the gearboxes, and secondly, the design of a tail rotor gearbox, based on a real design, and then its verification procedure, which involves the verification for static and dynamic loading on the components, the strength of the gear teeth, and the bearing life during operation. This verification is extremely important, both for the smooth and reliable operation of a helicopter, but most importantly for the safety of its crew.