108 Optimization of Binding Pressure of Bearing under Interference Fit

An interference fit is sometimes used to fasten two mating parts, e.g., a shaft and a hole, employing friction between the two parts. Inserting the shaft into the hole under interference fit, we must pay attention to the stress concentration around the hole. For example, on the near edge of the hole, high stress concentration arises on the hole, causing the plastic deformation and a misalignment of the shaft. This misalignment can also lead to abrasion of the surface of the two mating parts. Therefore, it is important to avoid this stress concentration under the interference fit. In our study, we propose a method for reducing the stresses on the contact area of the hole by cutting a groove into the side face of the hole. This cutting can release the contact stress between the two mating parts. On the other hand, this may weaken the frictional force of the contact surface. There is a trade-off between the cutting and the strong frictional force. Introducing an evaluation function of these two parameters and using the three-dimensional contact FEM analysis, we determine an optimal shape of the groove. Through the FEM simulation results, we demonstrate the validity of our method.