In gear design, what is the purpose of having a proper fillet between tooth radii?

The purpose of having a proper fillet between tooth radii in gear design is primarily to enhance load distribution. When gears engage, the forces transmitted through the contact points can create stress concentrations. A fillet serves to smooth the transition between the gear tooth and the root, which helps to distribute the contact loads more evenly across the surface of the gear teeth. This improvement in load distribution minimizes the chances of localized stress, which can lead to wear, pitting, or even failure of the gear under high loads.

By promoting a more uniform distribution of forces, the fillet design contributes to the longevity and durability of the gears. Additionally, it can help reduce the likelihood of crack propagation in the material, further contributing to the gear’s overall performance and reliability in mechanical systems. Properly designed fillets not only enhance the functional aspects of gear performance but also improve the efficiency of power transmission in a variety of applications.