[Popescu, 4(10): October, 2015] ISSN: 2277-9655 (I2OR), Publication Impact Factor: 3.785 http: // www.ijesrt.com© International Journal of Engineering Sciences & Research Technology [787] IJESRT INTERNATIONAL JOURNAL OF ENGINEERING SCIENCES & RESEARCH TECHNOLOGY KINEMATICS AND DYNAMICS STUDY ON THE BEADS OF THE MAIN AXLE BEARING FOR TECHNOLOGICAL SYSTEMS WITH HIGH ROTATION SPEED Daniel Popescu * , Ştefan Buzatu, Roxana-Cristina Popescu * Autovehicles Department, Faculty of Mechanics, University of Craiova, Department of Life and Environmental Physics, “HoriaHulubei” National Institute of Physics and Nuclear Engineering; Department of Science and Engineering of Oxide Materials and Nanomaterials, Faculty of Applied Chemistry and Materials Science, Politehnica University of Bucharest; ABSTRACT The paper presents a mathematical model for the analysis of kinematics and dynamics of the beads of the main axle bearing inside a high speed cutting machine tool. The use of this model creates the premises of determining the bearings rigidities in order to analyze the stability of the vibration. KEYWORDS: kinematics, dynamics, bearing bead, high cutting speed, rigidity, stability. INTRODUCTION The main characteristics which reflect the level of improvement and exploiting at machine tools are: productive capacity, high stiffness, easy manipulation, etc. Simultaneously, a perfecting in the technological processes was needed, by means of mechanization, automation and intensified operating modes, leading to a rigorous design of the cutting tools. The increased performances of the machine tools, of the CNC machining centers, the continuous development of new products, or products manufactured using CAD/CAM techniques, contribute to the increased precision of the manufactured parts. Also, the CNC machining centers are evolving by means of:  Having an increased productivity and flexibility by reducing the non-productive times;  Developing a surveillance and security system;  Increasing the dynamic performances (high rigidity, higher cutting speeds, enhanced positioning accuracy);  Multi-spindle machines for highly complex parts. In this context, the rigidity of the main spindle of the machine tool has a particular importance for the increase in dimensional precision and the quality of the obtained surfaces (Figure 1). Figure 1: Longitudinal section through the main axis;