As the running time of the air compressor goes on, the bearings of the main engine will inevitably wear out, resulting in axial turbulence and radial displacement of the screw. This change will cause the screw and the screw, the screw and the main body casing, and the front and rear. The gap between the end faces changes. These gap changes are normal and allowable over the life of the bearing, and the resulting air compressor aeration attenuation and main motor load increase are also normal and permissible.
As the unit running time approaches the main engine overhaul period, the life of the main engine bearing gradually increases to the maximum allowable time limit. At this time, the axial and radial turbulence of the screw gradually progresses to the maximum design allowable value, which causes a large change in the gap between the screw and the screw, between the screw and the main body casing and the front and rear end faces. At this point, although the host is still running safely, it is time to consider the planned overhaul of the host. Because once the unit running time exceeds the overhaul period, the bearing wear and the host matching clearance reach the limit value allowed by the technical conditions of the host. The Wuhan Giant Industry Air Compressor reminds you that the host is in an unsafe state at any time. The following serious consequences may occur:
1. The running load of the main engine increases, causing damage to the main motor and electrical system.
The strong friction that may occur between the main screw, between the screw and the front and rear end faces, between the screw and the main body casing, causes a drastic increase in the running load of the main engine, and the running load of the heavily worn bearing is also large. As a result, the motor will be in an overloaded state, which will seriously endanger the safe operation of the motor. In the case of serious conditions, if the electrical protection device of the air compressor unit is insensitive or ineffective, it may also cause the motor to burn out.
2. The air compressor exhaust volume will undergo a large attenuation.
The increase of the matching clearance of the main engine will lead to a serious decrease in the efficiency of the main engine, that is, the displacement of the air compressor will have a large attenuation, which will have a certain impact on the normal production of the gas unit. Especially for those users who have a small amount of air compressor exhaust capacity, because the air compressor exhaust volume is attenuated, the compressed air pressure of the pipe network will be much lower when the gas consumption of the gas system is relatively stable. It may happen that the gas system equipment does not work normally or does not work at all, which may affect the normal production of the unit or cause temporary shutdown, causing losses to the enterprise.
3, the most serious consequence is the sudden "locked" of the host.
In the event of such a situation, if the electrical protection system does not respond promptly or the protection fails, it may also cause serious damage to the main motor and electrical system.
For the handling of the host "locked to death", Wuhan Giant Industry believes that on the one hand, the maintenance cost of the overhaul will be much more expensive than the normal overhaul. On the other hand, due to the damage of the host components, the overall performance of the host will be overhauled after the repair. The host is worse. If the severity of the damage to the host has reached a repair value or cannot be repaired at all, it can only be abolished to replace the new host, and the direct loss is the biggest. Because the cost of the newly purchased mainframe is usually about one-third of the cost of purchasing the entire air compressor unit, which is much higher than the mainframe overhaul cost under normal circumstances, and the comprehensive technical performance and new host of the overhauled host under normal conditions. But it is very similar!
Wuhan Juye warm reminder, in summary, it can be seen that normal host overhaul work is not only the basic requirements for equipment maintenance, but also the basic requirements for enterprises to control normal equipment maintenance costs, avoid unnecessary capital losses and ensure normal production of enterprises!
Therefore, it is not only necessary but also necessary to overhaul the air compressor mainframe on time and according to the standard! The screw air compressor main machine needs to be overhauled:
To be precise, the time for the main engine to be overhauled should be based on the end of the service life of the bearing, but it is actually difficult to have accurate indicators to determine whether the service life of the bearing is about to expire or has expired, so the internationally famous air The standard determined by the press manufacturer based on its nearly 100 years of practical experience is to overhaul the mainframe after the compressor has been running for 20,000 hours or 4 years.
In addition to the above prevailing standards, based on experience, we can make a more accurate judgment on the status of the host from the following aspects:
1) The sound of the main engine running, especially if the bearing has abnormal noise;
2) the difference between the motor running current, especially the no-load operating current and the standard value;
3) Vibration of each bearing of the head.