M. Masjedi - Research Assistant School of Mechanical Engineering,,Sharif University of Technology, Tehran, Iran
M.R Movahhedy - Associate Professor, Corresponding Author School of Mechanical Engineering,,Sharif University of Technology, Tehran, Iran
M Behzad - Associate Professor School of Mechanical Engineering,,Sharif University of Technology, Tehran, Iran

Accurate and realistic modeling of high speed spindles is essential for design of precision high speed machine tools. The bearings play an essential role in the dynamic performance of the spindles and their behavior is usually nonlinear. In this work, a five DOF simplified model for angular contact ball bearings is presented which takes into account the effects of high speed rotation on variation of the contact angles of the inner and the outer rings of the bearing. The model uses an average contact angle calculated at each rotational speed. It is shown that considering the changes in contact angles has a small effect on dynamic behavior of the bearing for typical range of spindle speeds currently available on most high speed machine tools. Therefore, the presented model can be safely used for modeling of the spindle bearings in such spindles with reasonable accuracy and reduced computational cost.

Angular contact ball bearing, High speed machining, Machine tool spindle, Finite elements method