Regenerative Shock Absorber Using a Two-Leg Motion Conversion Mechanism

This paper presents the development of a novel regenerative shock absorber sized for a passenger car suspension system. The shock absorber includes a simple and highly efficient motion converter called a two-leg mechanism, a planetary gearhead, and a brushless three-phase rotary machine. The design and analysis of the regenerative shock absorber are presented by considering the dynamics and efficiency of the electromechanical device. The performance of the regenerative damper is evaluated under sinusoidal excitation inputs for typical amplitudes and frequencies in a vehicular suspension system. Experimental results show that a damping coefficient of 1720 N.s/m can be achieved by controlling the external loads. Furthermore, a mechanical energy conversion efficiency between 0.71 and 0.84 is achieved, which is considerably higher than other mechanisms reported in the literature, such as ball screw, rack-and-pinion, and linear mechanisms.