An Experimental and Theoretical Study of Gear Vibro-Impacts Caused by Torque Reversals

Abstract Rapid shift toward electrified powertrains has provided gear train dynamics researchers with new challenges, one of them being transient vibro-impact behavior caused by torque reversals during the drive and regenerative braking modes of operation. Contrary to ample studies on the steady-state dynamic behavior to aid with gear whine and rattle related noise and vibration problems, the transient behavior associated with such torque reversals has not been investigated extensively. Accordingly, this paper studies the dynamic response of a single-mesh gear system subjected to external torque reversals. A reduced-order dynamic model is proposed, accompanied by a computationally efficient piecewise-linear solution method. An experimental setup of the same system is developed. Measurements within a wide spectrum of operating conditions and system parameters are compared to the model predictions for its validation. At the end, the model is employed for key parameter sensitivity studies on the influence of drivetrain stiffness, backlash and torque magnitudes on the resultant vibro-impact behavior depicted by an impact severity index.