This paper presents the characteristics of tapered roller bearings (TRBs) taking into consideration the effects of tapered roller angle error which may occur during manufacturing. To this end, a TRB model including tapered roller angle errors was developed. The effects of tapered roller angle error on the contact load distribution, bearing stiffness and fatigue life were investigated with respect to changes in the tapered roller angle error. A statistical analysis of the fatigue life of TRBs was also provided with respect to tapered roller angle error. Simulation results show that the tapered roller angle error changes the load distribution of the rollers and causes angular misalignment in TRBs, and subsequently, influences the bearing stiffness and fatigue life. The statistical analysis shows that the Weibull distribution is an acceptable method to represent the statistical fatigue life for the practical range of tapered roller angle errors.

Rotary tables are often used to fix and support work-pieces in machine tools. Because the deformation of the rotary table is known to significantly affect the precision in the work of the machine tool, it is very important to accurately predict the static displacements of the rotary table subjected to internal and external loads. This paper deals with modeling and experimental verification of the static displacements of a large-size rotary table supported by a thrust cylindrical roller bearing (T-CRB) and a double row cylindrical roller bearing (D-CRB). To this end, a rotary table model was developed along with the quasi-static models for T-CRB and D-CRB. The equilibrium equation of the rotary table was derived, and solved one by one in the looping manner, to overcome its statically indeterminate characteristics. The proposed modeling method was verified by means of comparing to the experimental results. Finally, an extensive simulation was carried out to investigate the deflection of the rotary table subjected to cutting forces.