Virtual Development of a Light Weight Assembled Gear for Automotive Transmissions 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.