Safety Factor and Life Calculations for Cross Roller Slew Ring Bearings

Slew ring bearings takes axial and radial loads and moment simultaneously and are used in rotating mechanisms such as excavators and cranes for earthmoving equipment. For these applications, a cross roller bearings can be used and feature more stiffness than the ball type bearings. In this paper the static and dynamic equivalent loads are calculated for the cross roller type slew ring bearings such as cylindrical roller and tapered roller bearings. As a result, simple formulae were obtained to calculate the safety factors and bearing lives for the cross roller slew ring bearings under simultaneous eccentric axial load and radial load.