Design and test of a novel magnetic lead screw for active suspension system in a vehicle

This paper deals with the development of a magnetic lead screw (MLS) for the active suspension system in a vehicle. Initially, a brief introduction to the active suspension system of a vehicle, is given, thereby identifying the benefits of having an active suspension system in a normal vehicle. Furthermore the Magnetic Lead Screw is introduced and its benefits when used with an active suspension system are discussed. Based on a model of a quarter car, the design specifications for the MLS active suspension system are found, which leads to a design study. The design study investigates the relation between lead and equivalent mass. Additionally using a Bode diagram, the frequency response of the hydraulic standard damper and various configurations of the MLS active damper are compared. The designed prototype is constructed and various tests are performed, leading to full efficiency map for the developed prototype and identification of the total losses of the MLS system. It is concluded that the designed prototype functions as expected, however a decrease in stall force from the calculated 3D FEM value of 3.7 kN to approx. 3 kN is measured. Finally the efficiency map indicate the possibility of harvesting energy from the vehicle suspension system independently of damping velocity.