Dynamic characteristics and vibration suppression for extreme-condition lightweight gear systems

Gear transmissions increasingly demand high power density and reliability, and service conditions tend to be extreme: high speed, heavy load, and high temperature. However, existing dynamics models for conventional conditions exhibit incomplete modeling of extreme-condition nonlinear factors, large prediction errors, and susceptibility to over-limit vibration. This work aims to develop modeling methods for extreme conditions, including extended tooth contact in comprehensively modified gears under heavy load, thermal-mechanical characteristics of bearings, temperature field prediction considering high-speed windage loss, contact parameter calculation at rough interfaces under loss-of-lubrication conditions, gyroscopic effects in high-speed rotors, and lightweight gear meshing parameters. Spur gear dynamics under such conditions are analyzed using the finite node method combined with thermal-fluid-solid multi-physics coupling. The effectiveness of the proposed model is verified through finite element analysis (FEA) and experiments. Analysis reveals increased contact ratio in heavy-load gears, nonlinear growth of high-speed windage power loss with speed, and transmission efficiency peaking then declining. Conversely, bearing stiffness rises at high temperatures. Under a loss-of-lubrication operation, interface friction and vibration intensify, while appropriate gear lightweight structural design significantly reduces dynamic response. This work provides support for the design and analysis of extreme-condition lightweight gears.