Akademik Veri Yönetim Sistemi
European Mechanical Science, cilt.2, sa.6, ss.83-89, 2022 (TRDizin)
The presence of oscillating motion in a mechanical system is highly critical in terms of its service life. The service life of the bearings which are one of the common machine elements is calculated according to international standard ISO 281 with the equation depending on several variables such as basic dynamic load rating (C). One of the applications where bearings are used is universal joints on the driveshafts. The bearings for universal joints (universal joint bearing) are special bearings called as closed end needle roller bearings. The rolling elements used in a universal joint bearing are the needle rollers. They have a larger contact surface when compared to the ball elements, and this makes a positive difference on the service life of the universal joint bearings. Needle roller on a universal joint bearing is supported partially along its length, unlike a needle roller used in basic applications such a round bar. Because the universal joint bearing is pressed into a housing bore on the yoke part, and the trunnions of the cross shaft which acts as an inner raceway is mounted into the bearing. In this context, the length of the needle roller supported by the trunnion of the cross shaft and housing bore, which is called effective length should be considered to compute the dynamic load rating. In this paper, an approach to determine the effective length of the rolling element used in the closed end needle roller bearing of a driveshaft has been investigated analytically. And then, the effects of the said approach on the basic dynamic load rating and bearing life have been revealed by considering ISO 281.