What is the reason for the imbalance of the main engine in the air compressor

Analysis of the causes of imbalance of the main engine of air compressor

The imbalance of the main engine of the air compressor is an abnormal condition that needs to be paid attention to during equipment operation. The reasons for its occurrence can be systematically analyzed from the following four aspects:

1. Physical loss of core components

1. rotor system offset
   As the core rotating component of the compressor, the following problems may occur after long-term operation of the rotor:

• surface wear: Bearing friction causes the rotor shaft diameter size to change, destroying the original dynamic balance state
• deformation accumulation: High temperature operation causes metal fatigue, causing rotor bending or blade deformation
• foreign body attachment: Lubricating oil carbonized particles or metal debris adhere to form a local mass

2. Bearing system failure
   Failure of the bearings supporting the rotor will directly destroy the rotational accuracy:

• raceway damage: Insufficient lubrication causes direct metal contact, causing pits or peeling
• abnormal clearance: Installation errors or wear cause excessive bearing clearance, causing vibration transmission
• Damaged cage: Broken cage fragments change the trajectory of rolling bodies

2. Accuracy deviation of transmission components

1. Poor alignment of coupling
   Additional torque will be generated when there is a deviation in the connection between the motor and the main engine:

• angular deviation: The center lines of the two axes form an angle, causing periodic impact loads
• displacement deviation: Axial or radial offset destroys the smoothness of power transmission
• Aging of elastic elements: Failure of diaphragm or rubber ring reduces vibration buffering capacity

2. abnormal gear engagement
   Gear-driven air compressors should pay attention to:

• tooth surface wear: Pitting or peeling changes the engagement gap
• assembly error: Excessive side clearance causes periodic impacts
• lubrication failure: Oil film ruptures causing direct metal contact

3. Basic installation defects

1. insufficient rigidity

• The strength of the concrete foundation is not enough, causing resonance amplification effect
• The shock absorber ages and fails and loses its vibration isolation effect
• The anchor bolts are loose, forming a dynamic displacement space

2. environmental interference

• Vibration transfer from nearby equipment, forming coupled vibration
• The stress in the pipeline is not released, causing tension and compression to the main engine
• Temperature changes cause foundation deformation

4. System coupling effect

1. gas pulsation
   Periodic pressure fluctuations of compressed gas are transmitted to the main engine through pipes, forming gas-solid coupled vibration.
2. lubrication disturbance
   The oil system is blocked or the oil supply is unstable, causing periodic changes in the lubrication status of the bearing.
3. electrical harmonics
   Motor current harmonics may cause torque ripple during variable frequency driving.

countermeasures
Enterprises should establish a three-level testing mechanism:

1. daily inspection: Monitor the vibration speed (recommended to control it below 4.5mm/s)
2. regular testing: Conduct quarterly spectrum analysis to identify characteristic frequencies
3. Special diagnosis: Implement phase analysis on abnormal frequency bands to accurately locate fault sources

Through systematic investigation and preventive maintenance, the risk of mainframe imbalance can be effectively controlled and the stable operation of the air compressor system can be ensured.