Experimental and numerical analyses of the displacements and stiffnesses of a needle roller bearing under different conditions

The displacement and stiffness of a roller bearing affect the reliability and remaining life of the roller bearing. In order to establish a method for predicting the displacement and stiffness of a needle roller bearing, experimental and numerical analyses were performed on an NA4848 needle roller bearing under different conditions. The tested displacement varies from 0.0029 mm to 0.0125 mm for the radial load in a range of 10-50kN. Test results also showed that the effect of the tested rotational speeds on the radial stiffness is not significant. The minimum stiffness based on the tested displacement occurs when the radial loading is 20kN. Finite element analysis was performed, from which the displacements and von Mises/contact stress distributions of the NA4848 needle roller bearing under different conditions can be obtained. The FE predicted relative displacements and stiffnesses are compared with the analytical calculations and experimental results, which showed that the predicted values of the relative displacements were higher than the analytical calculations and experimental results by 0.009-0.018 mm, and the predicted values of the stiffnesses were higher than the analytical calculations and experimental results by 36 × 10⁶-164 × 10⁶ N/mm. In addition, it was found that the predicted values of the finite element method for the contact stresses were lower than the analytical calculations by about 400-600 MPa.