As we all know, the blockage of the oil-injected screw air compressor air end is a very serious equipment failure, which will lead to equipment damage, serious safety hazards, high maintenance costs in the later period, and cause relatively large economic losses.

Therefore, being proficient and mastering the reasons for the stuck air end of the oil-injected screw air compressor has a very important guiding significance for quickly solving equipment failures and avoiding and preventing serious faults of the air compressor. The common causes of air compressor air end stuck mainly include the following aspects:

(1) The bearing of the air compressor is aging and severely worn

The service life of the air compressor air end is the service life of the bearing, and the unit bearing has an important influence on the service life of the air compressor head. With the long-term production and operation of the air compressor, the size of the air compressor air end bearing will inevitably wear, resulting in the increase of the axial play value and the radial play value of the screw.  The gap between the screw and the main things shell and the front and rear surfaces changes. This clearance change is normal and permissible within the bearing life period, and the resulting air compressor air production decline and transmission motor load increase are also normal and permissible. However, when the bearing wear and the matching clearance of the main engine exceed the allowable limit, the axial movement value and radial movement value of the screw will increase. If the gap between the front and rear faces changes, the machine air end  may be stuck.

Preventive measures: Regularly inspect and maintain the air compressor unit. During the maintenance process, the bearings should be specially inspected. Check the bearing clearance, whether there is shaking or wear. If abnormal conditions such as bearing shaking and wear are found, the bearing should be replaced in time.

(2) Insufficient oil supply and low oil level during the operation of the air compressor will cause the machine air end to be stuck due to lack of oil.

Insufficient oil supply and low oil level of the air compressor unit, including untimely replacement or addition of lubricating oil, or blockage and leakage of oil circuit, will cause the bearings at both ends of the screw rotor to lose lubrication during operation, resulting in serious bearing wear and yin and yang screws. Friction stuck (hold) dead.

Preventive measures: Do a good job in the daily maintenance and regular maintenance of the unit, carry out daily inspections, check the oil level on time, and replenish the lubricating oil in time to avoid the engine air end locking due to lack of oil.

(3) Insufficient lubricating oil in the air compressor head

When the screw air compressor is out of operation for a long time, its internal parts, especially the oil in the air end will be insufficient. When the machine is started without attention, it will cause an instant lack of oil, resulting in the air end stuck.

Precautionary measures: For the screw air compressor unit that has been shut down for a long time, add enough oil to the air end before starting the machine, turn it manually several times, and then start the air compressor unit.

(4) Oil quality problem

Because the oil is not changed in time, or the oil quality is not good, there are too many impurities, and the lubricating oil contains impurities, carbon deposits, coking, and rust spots; the use of inferior lubricating oil or overdue use, the performance indicators of the lubricating oil decrease; mixing oil or oil too dirty and other reasons cause poor cooling and lubrication of the machine air end, and oil deposits cause the rotor and the casing to sinter together, which mostly occurs in the rotor exhaust end face and the casing or the rotor shaft and the inner hole of the casing. It is easy to cause the main engine ( nose) stuck accident.

Preventive measures: Use high-quality special lubricating oil for air compressors, carry out maintenance in strict accordance with the replacement regulations for air compressor lubricating oil, and regularly sample and analyze the unit's lubricating oil to ensure the quality of the unit's lubricating oil.

(5) The foreign things enters and gets stuck

When a foreign things is inhaled from the air inlet, it is extremely likely to cause a stuck.

Preventive measures: Check and maintain the air filter regularly to ensure that the air source entering the air compressor is clean.

(6) The unit is stuck in reverse rotation

When the screw air compressor reverses, the thrust generated by the compressed air will push the rotor to the exhaust end, causing the metal to contact and sinter and get stuck. Therefore, it generally occurs only when the protection fails, or when the motor wiring is replaced, the switch is replaced, etc.

Preventive measures: Regularly carry out self-protection maintenance of instruments and meters, and perform operations such as changing motor wiring, replacing switches, etc. in strict accordance with the maintenance operation procedures, so as to avoid the reverse rotation of the air compressor caused by the reverse jam failure.