Design Analysis and Optimization of Electric Solenoid Shroud for Starter Motor Used in Mild Hybrid Passenger Car

摘要

Starter motor is used to start the engine by cranking the flywheel by means of pinion and ring gear engagement through electrical solenoid linear activations. Solenoid linear movement has to be activated in few milliseconds for starter and engine ring gear engagement which is very crucial design in it. The parts involved in solenoid for linear activations are very sensitive in environmental conditions. This is causing high durability impact, warranty cost and less reliability. The paper discusses the solenoid shroud redesign for the better performance and higher durability with suitable silicone polymer material to withstand the temperature and nonlinear characteristic for the solenoid linear activation of starter motor start stop application. The shroud design talks about the packaging of the shroud to meet the overall starter sizing and sealing capability of the shroud and its deformation characteristics which talks about the geometry nonlinearity and design for interference and with starter housing. The comparison between natural rubber and specially selected silicone polymer for the shroud application is detailed. Hence the results of the paper discussed on the methodology of the shroud design and analysis procedure and material selections. The finite element analysis of the shroud considering its environmental factors has been explained. The effect of material for the smooth solenoid operation has been explained which impacts the application of shroud in solenoid used starter motor for the start stop mild hybrid passenger car application.