The problem of overheating and fallibility is exist in the friction clutch brake in crank press.On foundation of analysis of the reason

the relationship between heat value and rotating speed is explained.The method of determining critical speed is proposed.The improvement solution is pointed out that the presses are driven by switched reluctance motor and the running situation of regulating speed

variable speed and PID gentle control speed are controlled by taking the critical speed as datum.The practice example is tested.The results show that the rising temperature of clutch brake is below 60℃ after 90min on continuous single running after the improvement solution is applied.For the rotating speed of clutch brake is higher than the critical speed

the problem of clutch brake is solved thoroughly by the type of no-clutch.