Testing method for the evaluation of parametric excitation of cylindrical gears

Nowadays, quality, vibrations, and noise have become increasingly important considerations in gear design. Recent gear research has shown that variation in gear mesh stiffness and transmission error are the primary sources of vibration excitation in gear drives. However, standard gear geometry and quality measurements do not contain information about parametric excitation. Once the gears are located in the housing with shafts and bearings, the shape of parametric excitation in the operating load cannot usually be determined. The experimental method developed, based on frequency measurement along the line of action, showed many essential features, which cannot be detected with standard methods. The behaviour of the contact ratio and the effect of load, profile corrections, wear, and manufacturing errors can be seen in the results. The frequency measurement method developed is quick to use and can be applied to real gears with shafts and bearings. The natural frequency variation in the gear test rig structure was also calculated with a lumped mass model, which has been developed and which utilized the mesh interface model where the mesh stiffness variation was calculated with finite elements. Test gears evaluated demonstrated that, in general, the calculated results are in reasonable agreement with the experimental results.