Dynamic behaviour of large helical gears

Abstract

Abstract

Inertia forces resulting from small changes in velocity ratio between pinion and wheel excite gear noise and vibration. These are caused by a combination of geometric errors and variable elastic mesh deflections. The forces are transmitted through the bearings to the gearbox structure, and so either generate airborne noise or lead to excitation of other structures. In this investigation of gear noise, the dynamic forces excited at the bearing at tooth contact frequency (TCF) are considered as the ‘noise parameter’. This has been used to compare gears of differing geometry at varying load and speed conditions. The test programme is based on typical, large face width, marine propulsion gears running in the UK 8 MW gear noise test rig at the University of Newcastle.