Compressor during operation, due to mutual friction between the respective bearing and wear occurs. Gradually reach compressor overhaul period of use, the host bearing gradually close to the maximum use of time, this time, the screw axis and runout other changes will happen gradually close to the maximum allowable value of design, and brought the screw, etc. the gap between the components change, this time the compressor is running there is a considerable risk, if the bearing wear or cell gap exceeds the maximum allowable value, will result in serious consequences. Hazard screw compressor host extended use: if the host compressor running time exceeds a predetermined value and there is no time for a major overhaul, bearing wear or component clearance exceeds the maximum allowable value, then the compressor's operating status is unsafe, followed bring a series of serious consequences: 1. Host runtime required to increase the carrying capacity of the motor and the entire system will cause serious harm to the displacement compressor 2. 3. will greatly reduce or even cause a host suddenly "Hugging" and other serious consequences