This paper presents a novel five degrees-of-freedom model for the static analysis of linear roller bearings subjected to external loading. In this study, first, a rigid analytical model was developed to obtain the roller contact loads and displacements of carriage caused by the elastic deformation at the roller–carriage and roller–rail contacts. The non-Hertzian contact loads between the rollers and raceways were utilized to consider the profiled roller and/or profiled guide rail. Next, the structural deformations of the carriage owing to the contact loads were computed using the finite element method. The associated displacements of the carriage top were derived systematically. Then, the total displacements of the carriage top were obtained by summing the displacements estimated from the rigid model and the induced structural displacements obtained by finite element method. The proposed model was validated by comparing the calculated displacements of the carriage with those from a commercial program under various loading conditions. Further investigation regarding the effect of preload on displacements of the linear roller bearing was conducted. The simulation results showed the dependence of carriage rigidity and internal load distribution on the linear roller bearing characteristics.

This paper dealt with the fatigue life of cylindrical roller bearings with several significant error sources that may occur during installations. A four degree-of-freedom quasi-static model for cylindrical roller bearings was developed, which took into account potential error sources such as angular misalignment, axial offset, and radial clearance, together with inertial loading by rotational speed and induced moment loads. A 3D contact model was employed to provide contact pressure distributions in rolling elements. The fatigue life of a cylindrical roller bearing was analyzed as a function of angular misalignment under various loading conditions. Then, the fatigue life analysis was extended to the combined effects of radial clearance, axial offset, and the number of rollers, along with angular misalignment. The computational results showed the significance of each error source on fatigue life. They further showed that cylindrical roller bearing fatigue life maximized when the radial clearances were slightly negative, and that it increased almost linearly with the number of rollers.

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