A thermally stable aerostatic spindle system equipped with self-cooling function

High efficiency and high precision machining technologies have been recently required in a variety of industries. In general, aerostatic spindle systems can realize such machining, while at high speed rotation it generates a large amount of heat that causes thermal deformation of the spindle. However, few research papers on thermal deformation-minimized spindle systems have been published so far. This paper presents a newly developed aerostatic spindle system driven by a built-in air turbine. The developed spindle system has a self-cooling function of the air turbine with internal air flow. In addition, the spindle system has a compact and simple structure compared with the conventional spindle cooling systems. The built-in air turbine is designed so as to improve the cooling and torque performances. Actual spindle rotational experiments are performed in order to evaluate rotational accuracy and thermal characteristics of the spindle system during high speed rotating. Experimental results confirmed that the spindle system can minimize thermal deformation of the spindle by the self-cooling function.