AN EFFECTIVE MODEL FOR CALCULATING THE NONLINEAR RIGIDITY OF BALL BEARINGS

Abstract

An analysis of the features of the static calculation of the spindle assembly for stiffness, taking into account the stiffness of the supports, was carried out. It is noted that during the static analysis of spindle shafts, approximate reference values of the rigidity of supports - rolling bearings are usually used. which can give an error in estimating the stiffness of the support up to 50%. The paper presents an analysis of the modified Jones-Harris method for calculating the stiffness of bearings, which provides an increase in accuracy due to new constants in the dependencies for the radial stiffnesses of support and support-thrust ball bearings. The finite element models used instead of the Hertzian contact model in the modified Jones-Harris model in the contact problem "rolling element - bearing rings" more accurately reflect the geometry and stiffness of the bearing raceways, which allow obtaining more accurate constants for the nonlinear stiffness model of ball bearings. The advantage of the modified model is the possibility of automatic calculation of the technological gap in the bearing and the speed of rotation of the shaft. The calculation of the stiffness of SKF bearings showed greater accuracy, which is confirmed by comparison with the experiment. The results of the stiffness calculation obtained for a number of SKF bearings can be successfully used for practical stiffness calculations of radial and radial thrust ball bearings of other firms, the structural and technological characteristics of which correspond to the characteristics of the SKF bearings considered in the work.