Over the compressor run time, the host is bound to happen each bearing wear, causing the screw to produce axial movement and radial displacement increases, the variation between the screw and the screw will screw around with the host of the housing and the gap between the faces change. These gaps vary within the bearing lifetime is normal, allowed, while the air compressor gas production resulting attenuation and the main motor load increase is normal, permissible.
With the unit running time close to the overhaul of the host, the host bearing life gradually getting into the maximum allowed limit. In this case the screw axial and radial runout gradually getting into the design to allow maximum value will change between the screw and the screw, screw gap with the host between the housing and the front end face of the larger changes. The host is running, although still safe, but have come to consider scheduling time for a major overhaul of the host. Because once over the overhaul of the unit running time, with the gap bearing wear and host mainframe technology reached the limit conditions allow, at this time the host is in unsafe operating condition, it may at any time following the occurrence of serious consequences:
1, the host running load increases, the main motor and electrical system hazards
Screw between hosts, between the screw and the front and rear end faces intense friction may arise between the screw and the host of the housing will cause a sharp increase in the host operating load, in addition to operating load bearing severe wear is great. As a result, the motor will be in working condition overload would seriously endanger the safe operation of the motor. The situation is serious, and if electrical protection device reaction compressor group insensitive or fails, may also cause the motor to burn.
2, the compressor displacement will occur more substantial attenuation.
Host with the gap increasing efficiency will lead to a host of serious lower, which produce relatively large displacement compressor attenuation certain impact on the normal gas production units. Especially configured user affluent smaller amount for those compressor displacement, due to the compressor displacement attenuation, gas consumption in the gas system is relatively stable, the pipe network air pressure will be reduced a lot, you possible gas system equipment does not work or does not work, which appeared normal production of the affected units or cause temporary shutdowns, cause losses to the enterprise.
3, the most serious consequence is the sudden emergence of a host of "locking."
Once this happens, if the electrical protection system response is not timely or protection failure, also may give the main motor and electrical system caused serious damage.
For the host "locking" of the process, Wuhan giant industry believes that on the one hand maintenance costs overhaul overhaul will be much more expensive than normal, partly because there will be damage to the host cell, and therefore the overall performance after the repair will host than normal overhaul Host to be worse. And if it is the severity of the damage has been host to the non-repair value or simply can not be repaired, it can only be replaced with new hosts scrapped off, direct losses are greatest. Because the cost of newly purchased hosts usually around to buy the whole third of the cost of air compressors, far higher than the host overhaul costs under normal circumstances, and comprehensive technical performance under normal circumstances overhaul qualified host and the new host but it is very similar!
Wuhan Giant Tips, analysis shows that the basic requirements for normal work of both the host equipment maintenance overhaul, as well as corporate control normal maintenance costs, avoid unnecessary loss of funds and guarantee the basic requirements for normal production of the Fully!
Therefore, the air compressor host on time, according to the standard for a major overhaul is not only necessary, but also a must! Screw compressor host needs a major overhaul of judgment:

Rather, host overhaul of time should be subject to the expiration of the service life of the bearings, but in fact very difficult to have accurate indicators to determine whether the bearing life is about to expire or has expired, so the world's leading air After the press manufacturers are running 20,000 hours or four years of practical experience in the compressor according to their criteria established nearly a century to host a major overhaul.
In addition to the above prevailing standards, based on experience but also from the following aspects of the host state to make more accurate judgments:
1) Voice host runtime, especially bearing any abnormal sound;
2) The motor running current, especially the difference between no-load operating current standard value;
3) each bearing head vibration.