Increasing Strength and Reliability of Interference Fits
Interference fits, commonly referred to as press fits and shrink fits, are traditional methods for joining cylindrical parts. In an interference fit, the inner part - for example the shaft, bearing or bushing - is machined to be bigger than the mating hole of the outer part - for example the gear or housing. The larger part is then forced into the smaller part, both deform slightly to fit together, and extremely high friction results between the parts. Friction is so great that even large amounts of torque cannot separate the two locked parts.