An experimental and theoretical study of the dynamic behavior of double-helical gear sets

In this study, dynamic behavior of a double-helical gear pair is investigated both experimentally and theoretically. In the experimental side, a new double-helical test set-up consisting of a test machine and test specimens is developed for operating a double-helical gear pair under realistic torque and speed ranges. A test gear pair formed by novel three-piece double-helical gears is developed to allow adjustable right-to-left stagger angles. A measurement system to capture three-dimensional vibratory motions and dynamic motion transmission error under high-speed conditions is implemented. A test matrix that included various combinations of key system parameters is executed under realistic torque values within a wide speed range to establish a database. In view of this experimental data, a linear, time-invariant dynamic model of double-helical gear pair systems including shafts and bearing supports is proposed, also allowing for any stagger angle between the right and left sides of a double-helical gear pair through proper definition of phasing between the two gear mesh excitations. Direct comparisons to measurements are presented to demonstrate the accuracy of the proposed model in predicting three-dimensional gear vibrations. The right-to-left stagger angle is shown to be the most critical parameter impacting dynamic response.