This paper discusses the overall design and development of Rack and pinion steering (RPS) gear assembly in terms of gear calculations, DVP, modeling, performance characteristics, strength analysis and physical testing. Design calculations for gear meshing included several parameters like normal module, transverse module, helix angle, no. of teeth as per steering gear ratio, pinion shaft angle etc. A complete geometry of the RPS gear assembly was developed using CAD software UG-NX as per vehicle requirements. BIW(Body in white)and its surrounding parts clearance from the RPS assembly were verified for packaging review.
Performance study of the assembly includes simulation-based prediction using MSC Adams for estimation of various output parameters like free pinion Torque and its variations over rack travel, rack force required for rotating pinion, gear ratio, relation between input torque of pinion and output load to find rack efficiency. Strength tests of the assembly are done to find the areas of stress locations using FE analysis. Rubber boot clearance study with steering gear components is assessed for various tie rod envelope conditions.
This paper will conclude with experimental testing and its correlation with simulation results.