In recent years, numerical control machine has got important status and predomination in manufacturing of China. Numerical control machine has grown as key and deciding factor in many plants. Without timely fault diagnosis and service, serious economic loss can be caused. According to the Stat, about 60 percent of machinery fault in numerical control machine is fault of headstock. Therefore, headstock is the key segment in fault finding field, and the fault diagnosis on the headstock is becoming more and mo...