Experimental determination of rolling element bearing stiffness

In 1990, Lim and Singh presented a complete 6-dof roller-bearing stiffness model. The experimental verification (using an instrumental variables identification procedure) of all the stiffness coefficients of such a bearing appeared to be difficult, because the experimental setup showed some unexpected properties. In this paper the (modified) experimental setup will be presented to get reproducible measurements. Estimating all the stiffness matrix coefficients simultaneously from measured transfer functions still appeared to be unfeasible. Therefore, a 1-dof amplitude fit procedure has been applied. The results appear to be very promising and applicable in practice, but future research certainly is necessary to understand the remaining differences between the mathematical model and measurements. In addition to stiffnesses, the procedure also gives damping values. Finally, matters such as hysteresis, reproducibility and reciprocity have been investigated.