Analytical/Computational Investigation of Planetary Gear Dynamics in Rotorcraft Transmissions

摘要

This research is a comprehensive analytical and computational investigation of the dynamic response of planetary gears. In military helicopters, planetary gears are typically the last stage gear reduction whose output drives the main rotor. Their vibration is the dominant source of cabin noise. The project objectives are to: * Develop analysis tools and engineering knowledge to reduce helicopter transmission dynamics and increase their reliability. * Develop analytical, lumped-parameter models that capture the complex, nonlinear tooth mesh interactions typically observed in multi-body, multi-mesh planetary gears. * Validate analytical modeling with a unique finite element-contact mechanics formulation that captures the tooth mesh forces and contact mechanics with accuracy beyond that achievable with conventional finite element tools. * Examine helicopter planetary gear dynamic response under operating conditions with coordinated analytical and computational simulations. Validate findings with experiments through related ARO DURIP and NRTC/RITA sponsored projects. * Identify techniques to minimize planetary gear dynamics and the associated cabin noise with intelligent early design. * Interact continuously with Army Research Lab staff at NASA Glenn and Army helicopter contractors regarding the Army technical needs and the findings of the research. Transfer technology and simulation tools to these parties and other US industry.