Roller-Raceway Slip Simulations of Wind Turbine Gearbox Bearings Using Dynamic Bearing Model

A six degree of freedom dynamic bearing model (DBM) has been used to simulate roller-raceway slip for a cylindrical roller bearing used in an intermediate shaft location of a wind turbine gearbox. The DBM simulates the motion of bearing components such as an inner raceway, a cage, and cylindrical rollers. Radial internal clearance and operating conditions such as load and speed were varied in order to identify the most critical parameters governing roller-raceway slip. The results indicate that significant slip occurs during rapid transient accelerations and decelerations, but these high slip conditions decay to a much lower level of slip at steady state. The results also demonstrate that extreme slip occurs for low load and high speed conditions because of concomitant contact area reduction and traction loss at the roller-raceway interfaces.