Analysis of a helicopter main gearbox by means of numerical modelling approach

Abstract

The main Gear Box is one of the most critical component of a helicopter drivetrain: high torque and high torque redaction ratio are involved in a lightweight box, including a complex system of gears, bearings and shafts. One of the interesting parameters of the investigation of this complex assembly is the evaluation of the displacements under loads of the gears: this analysis is judged as necessary and meaningful for a prediction of the geometric profile modifications thus saving cost and time with respect to an investigation by means of experimental measurements. The purpose of this work is therefore to describe the modelling approach of a complex Main Gear Box of an actual helicopter using a FE method approach. Even if the gearbox is a very complex assembly of several components, the aim is to reduce the complexity in the characterization of all the parts, ensuring confidence and likeliness in the results.