Abstract: The traditional analysis method for dynamic modeling a localized defect of a cylindrical roller bearing is based on Hertz line contact theory, however, the contact conditions between the roller and the races are not Hertz line contact since the roller profile is not straight line when its rollers are crowned. Hence, a new dynamic model of a cylindrical roller bearing with a localized defect on its races is proposed, which considers the non-Hertz line contact characteristics between the roller and the races and the time-varying displacement impulse. The effects of the different displacement impulse functions and the defect sizes are investigated. The results show that the proposed method can consider the radius of curvature of the raceway and provide a more close to practical contact between the roller and the localized defect on the surface of the races of the cylindrical roller bearing. It is also shown that the proposed method provides a new calculation method and some valuable conclusions for dynamic analysis and faults diagnosis of rolling element bearing.

Key words: cylindrical roller bearing;localized defect;non-Hertz line contact;time-varying displacement impulse;dynamics