Souza, T., Moraes De Souza, M., and Savoy, J., "Virtual Development of a Light Weight Assembled Gear for Automotive Transmissions," SAE Technical Paper 2012-36-0190, 2012, doi:10.4271/2012-36-0190.
CO₂ emission reduction through weight saving remains a huge challenge for all automotive components. When it comes to gears, the state of the art shows low potential of weight reduction due to the trade-off between mass optimization and manufacturing process. Gears are usually forged followed or not by teeth cutting operation. Current presses must operate with a minimum distance between punch and die, due to the elasticity of the equipment, in order to avoid tool failure when it operates with no working piece. Also, the press force is determined by this gap, in cases that some flash is formed during forging, and a minimum flash is required for a forgeable part using the available press. This issue constrains the minimum wall thickness of a final product, for instance, the body of an automotive gear. Therefore, some gears designs must have bigger wall thickness than necessary due to this conceptual restriction, even if thinner walls would be approved by classical criteria, such as stiffness, permissible stress and NVH.This work analyzes an innovative solution with flexible design for gear bodies, where the assembly process eliminates the current manufacturing process trade-off.