SUSPENSION RATIOS OF MACPHERSON STRUT SUSPENSION

Abstract

Bearing in mind the important role of the suspension system in maintaining ride comfort, stability and safety of the car by transferring the forces and moments from the road to the car body in strictly determined manner, the aim of the research presented in this paper was to derive analytically the suspension force ratios. Two suspension ratios were defined – the first at the connecting point between the shock absorber and the car body and the second at the connecting point between the lower arm and wheel hub. The spatial geometrical model of the MacPherson strut suspension was used to establish the relationships between the defined suspension force ratios and main suspension geometry factors. The results of the analysis of the influencing factors on the suspension ratios were presented and discussed. Car designers can use the derived analytical expressions to check how geometrical layout of the suspension characteristic points influences the suspension ratio and use this knowledge to optimize the design.