Powder Metal Gear Technology: A Review of the State of the Art

During the past 10 years, the PM industry has put a lot of focus on how to make powder metal gears for automotive transmissions a reality. To reach this goal, several hurdles had to be overcome, such as fatigue data generation on gears, verification of calculation methods, production technology, materials development, heat treatment recipes, design development, and cost studies. All of these advancements will be discussed, and a number of vehicles with powder metal gears in their transmissions will be presented. How the transmissions have been redesigned in order to achieve the required stress levels while minimizing weight and inertia, thus increasing efficiency, will also be discussed.