Nagapillai Durairaj, S., Ganesan, T., and Chakrapani Rao, P., "Starter Motor Light Weighting through Use of Alternate Materials," SAE Technical Paper 2017-28-1967, 2017.
Global Automotive Industry is mandated with the task of emission reduction and mileage improvements. One of the key areas being looked at from mileage standpoint is light weighting. While Aluminum body is replacing Steel is many vehicular applications, in Starter Motor Aluminum is the key component. Therefore, any attempt at light weighting must consider Aluminum.A Starter motor fits directly on to the engine. Aluminum being the housing material provides structural stability. It also performs the role of heat dissipation being a good thermal conductor and source of electrical ground path. Aluminum constitutes 20 - 25% of Starter motor weight. Any significant weight reduction cannot be achieved unless we look at the components made of Aluminum, namely die cast Housing and End plate. The alternatives considered in this study include engineered plastics, magnesium alloy and composites. The prime reasons for evaluation of these materials include the ones listed above - structural stability and strength, electrical and thermal conductivity.Detailed study was carried out which included material characterization, FEA analysis, thermal studies and finally rigorous physical testing.The results present the comparison of all the various alternate materials. The ultimate deciding factor must include cost as these materials, while scoring over Aluminum in weight (density) cost a premium. The paper will also address the tradeoff - cost vs. benefit, for the car manufactures if they decide to choose the alternative.