Experimental study on vibration characteristics of double-helical gearbox with isolators

A power closed double-helical gear test rig with isolators was created to investigate the dynamic response characteristics of the double-helical gearbox. Experimentally, the vibration accelerations of the bearing seat, machine foot, and base were tested under various working conditions. Experiments validated the validity of the generalized finite element theory-based dynamic model of the double-helical gear system. The study found that the unloaded vibration of the gearbox is greatly caused by the shaft frequency excitation due to assembly/manufacturing errors. As the load increases, the assembly/manufacturing errors are compensated by the system deformation. In the acceleration spectrum of the bearing seat, it is found that the tooth surface modification can reduce the amplitude of the mesh frequency, but the bearing outer ring frequency components are increased. That is, the axial movement of double-helical gears is intensified. Furthermore, the closer the excitation frequency is to the natural frequency of the base, the worse the vibration isolation effect is.