Fatigue Strengths of Shafts with Press-fitted Collar

Abstract

Canti-lever type fatigue tests were carried out on press-fitted and related specimens of 50 mm dia. Results obtained were as follows : (1) The hardness of a collar had little effect on the fatigue limit of a press-fitted specimen. (2) If the collar was press-fitted by superposing over the fillet of shouldered shaft, the fatigue limit was lowered remarkably as compared with that in the case of press-fitting alone. (3) The fatigue limit of the press-fitted specimen was reduced even under very light press-fit pressures, and the press-fit pressure had little effect on the fatigue limit. (4) When the collar was press-fitted closely to the shoulder with a very sharp fillet, the fatigue limit was lowest but not lowered as compared with that of a shouldered specimen with a very sharp fillet.