Answer: The main engine of the air compressor is the core part of the air compressor and is in high-speed operation for a long time. Since the components and bearings have their corresponding service life, they must be overhauled after a certain period of time or years. In general, the overhaul work mainly focuses on the following items:
(1) Clearance adjustment.
1) The radial clearance between the yin and yang rotors of the main engine increases. The direct consequence is that the leakage (i.e. back leakage) of the compressor increases during the compression process, and the volume of compressed air discharged from the machine decreases. In terms of efficiency, the compression efficiency of the compressor decreases.
2) The clearance between the yin and yang rotors and the rear end cover and bearing increases, which mainly affects the sealing and compression efficiency of the compressor, and also has a great impact on the service life of the yin and yang rotors. The overhaul is to adjust the rotor clearance to avoid scratches or wear on the rotor and the shell.
3) Strong friction may occur between the main engine screws, between the screws and the front and rear end faces, and between the screws and the main engine housing. The motor will be in an overloaded working state, which will seriously endanger the safe operation of the motor. If the electrical protection device of the air compressor unit is not responsive or fails, the motor may also burn out.
(2) Wear treatment. As we all know, any machine will wear out during operation. Under normal circumstances, the wear will be reduced a lot due to lubrication by lubricating fluid, but the wear will increase slowly with long-term high-speed operation. Screw air compressors generally use imported bearings, and their service life is also limited to about 30,000 hours. As for the main engine of the air compressor, in addition to the bearings, there is also wear on the shaft seal, gearbox, etc. If the correct preventive measures are not taken for slight wear, it is easy to cause increased wear and damage to the components.
(3) Main engine cleaning. The internal components of the air compressor main engine are in a high-temperature and high-pressure environment for a long time. In addition to high-speed operation, there will be dust and impurities in the ambient air. After these fine solid substances enter the machine, they will accumulate with the lubricating oil and form larger solid blocks over time, which may cause the main engine to jam.
(4) Cost increase. The cost here refers to maintenance cost and electricity cost. Since the air compressor main engine has been running for a long time without overhaul, the parts are worn out and some impurities are left in the main engine cavity, which will shorten the life of the lubricant. At the same time, due to impurities, the service life of the oil-gas separator core and the oil filter period is greatly shortened, resulting in increased maintenance costs. In terms of electricity costs, due to increased friction and reduced compression efficiency, electricity costs will inevitably increase. In addition, the decrease in gas volume and compressed air quality caused by the air compressor main engine will also indirectly increase production costs.
In summary: Normal main engine overhaul work is both a basic requirement for equipment maintenance, and overdue use has serious safety hazards. At the same time, it will bring serious direct and indirect economic losses to production. Therefore, it is not only necessary but also necessary to overhaul the air compressor main engine on time and according to standards.
At present, it is recommended to carry out condition maintenance for transfer equipment, and the above content can be used as a reference.
