Jixie chuandong (Mar 2019)
Analysis on Cage Dynamic Characteristic of Roller Bearing Under the Condition of Simple Harmonic Rotational Speed Fluctuation
Abstract
The rotational speed fluctuation will worsen the internal contact state of roller bearings，which has important influence on the dynamic characteristics of cage. Considering the characteristic of periodic fluctuation of rotational speed of roller bearings，it is simplified as a simple harmonic wave. Taking cylindrical roller bearing NU306 as investigation object，a nonlinear dynamic finite element model for plastic material flexible contact of a bearing is established. Based on explicit LS-DYNA，the dynamic simulations for nonlinear operation process under different fluctuation frequency and different fluctuation amplitude condition of rotational speed are carried out，and the angular speed curve of cage and the contact force curve between roller and cage are obtained. The influences of fluctuation frequency and fluctuation amplitude on the dynamic characteristics of cage are analyzed. The study results show that the fluctuation period of the angular speed curve of cage is mainly determined by the fluctuation period of the rotational speed of inner ring，and the greater fluctuation frequency of rotational speed，the more the number of collisions between rollers in and out of load zone and cage. The greater fluctuation amplitude of rotational speed，the greater maximum speed of angular speed curve of cage，and the smaller minimum speed of angular speed curve of cage，but the change of average speed is very small，so the fluctuation range of angular speed curve of cage will increase obviously. The simulation results are in good agreement with the experimental results， and the correctness of the finite element model is verified.
