This paper concentrates on theoretical and experimental nonlinear stiffness study of milling machine tool spindle angle contact ball bearing. The theoretical study allows us to build an analytical model to define nonlinear stiffness of angle contact ball bearings based on geometrical and physical parameters. Modifications were done on literature's models (e.g. Balls deformations) having positives impacts on conformity of models to experimental results.

FEM model using ANSYS is constructed to analyze the different parameters affecting the nonlinear stiffness of ball bearing. Among those parameters are physical including the geometry, friction coefficient and the boundary conditions of the model and Numerical parameters such as mesh density and penetration.

Experimental tests were done on the spindle ball bearing 7014, to measure the rigidity. Universal tensile testing machine is used to achieve load displacement curves. The developed theoretical model, constructed finite element model and experimental results showed good conformity.

This work presents the dynamic modeling of ball bearing which uses multibody dynamicformalism. Such formalism allows immediate integration of the model in dynamic simulationsof helicopter main gear boxes. Ball bearing is considered non-lubricated in order topredict its behavior in case of lubrication system failure. Rolling contacts are treatedwith the method proposed by Kalker. This approach is based on polynomial approximation ofrelative displacement on the contact ellipse. For low computational cost and without anyspatial discretization, it gives a good estimation of tangential traction and creep. Also,a regularization of the Kalker linear creep theory is proposed. It is used here tofacilitate the global convergence of the Newton iterative process. It is well suited formultibody dynamic simulations which do not need a very fine treatment of rolling contact.A numerical example of a ball bearing under thrust load is presented.