Design of intelligent spindle for high speed machining

Summary form only given. The spindle is the most important component in a high speed CNC machine tool. Its thermal and dynamic behaviors are almost decided by the drive system and the support system of the spindle. Some special requirements for high speed spindles must be satisfied; C-axis control is also required. A high speed, high power spindle driven by a built-in motor has been developed. The frameless spindle motor is located between the bearings. The frameless motor is cooled by an air-water cooling system. Si/sub 3/N/sub 4/ ceramic ball bearings are used to support the spindle. An oil-air lubricator is used to reduce the friction force and control the temperature-rise. Some design problems are discussed for improving the behaviour of the machine tool.