Have you ever wondered why your air compressor needs a major overhaul? As the usage lifespan of an air compressor increases, various issues arise with its components, such as main shaft bearings wear and screw displacement. When major components near their maximum allowable lifespan, an overhaul becomes inevitable.
The lifespan of the main shaft bearings gradually approaches its maximum allowable limit, and the axial and radial displacements of the screw gradually approach their maximum design allowable values. This change results in significant gaps between the screw and the main shaft bearings, and the screw and the front and rear faces.
While the compressor may still operate safely, planning a major overhaul becomes necessary. Operating beyond the overhaul period puts the compressor in an unsafe state, risking serious consequences:
- Increased load on the main motor and electrical system.
- Intense friction between the screws and the front and rear faces, and the screws and the main housing may lead to a rapid increase in the compressor’s load. This puts the motor in an overloaded state, posing a serious threat to its safe operation. In severe cases, if the electrical protection devices of the air compressor unit are unresponsive or fail, it could lead to motor burnout.
- Significant reduction in the compressor’s airflow.
- Increased main housing clearances result in a severe drop in compressor efficiency, causing a substantial decline in airflow. This can impact the normal production of units relying on a stable compressed air supply. Especially for users with limited compressed air capacity, reduced airflow may lead to a decrease in network air pressure, affecting the proper functioning of equipment or even causing temporary production stoppages.
The most severe consequence is the sudden “locking” of the compressor.
What Does a Screw Air Compressor Overhaul Include?
|Replacement of all main rotor drive bearings
|Replacement of the main rotor mechanical shaft seals and oil seals
|Replacement of shims for main rotor clearance adjustment
|Replacement of seals for the main rotor
|Adjustment of the main rotor radial clearance within the allowable range
|Inspection and replacement of main and auxiliary gears if worn
|Inspection of couplings and elastomers for damage, with replacement if necessary
|Adjustment of gearbox main and auxiliary drive bearings
Note: The above is a standard overhaul. Detailed information for scenarios like machine lockup can be found in the following section.