Gyroscopic Bearing Loads in Vehicular Flywheel-Based KERS

In this work, we investigate the rotor bearing loads of a flywheel-based KERS that are caused by dynamic forces and gyroscopic torques during representative driving maneuvers. Based on the governing equations of motion of a gyroscope, the equations for the rotor-platform interactions are developed. These equations, which relate the vehicle's roll, pitch and yaw rate with the internal transverse torques on the flywheel, are integrated into a commercial vehicle dynamics program. An average passenger car model equipped with a typical high-speed flywheel energy storage system is used for the numerical investigations. The flywheel bearing loads produced by some selected, representative driving maneuvers are simulated for different orientations of the flywheel spin axis relative to the body frame. In addition, the dynamic response of the vehicle to the reaction torques is investigated in open and closed-loop vehicle dynamics simulations. Thus, the steering response of a driver model to the gyrodynamics of a flywheel-based KERS is obtained for fully charged KERS as well as during braking and under acceleration boosts. The result of the study is an overview of the flywheel bearing loading characteristics caused by vehicle maneuvering, and the vehicle's dynamic response to the induced gyroscopic torques.