What are the consequences of not lubricating an air compressor?

Lubrication failure leads to severe component wear.

One of the core functions of lubricating oil inside an air compressor is to reduce mechanical friction. If no oil is added or if the oil level is severely insufficient, high-speed metal components such as rotors, bearings, and gears will lose their oil-film protection and experience direct dry friction.

• Bearing damage:Dry friction generates extremely high localized temperatures, which can cause bearing cages to deform or balls to fracture.
• Rotor wear:The clearance between the male and female rotors is extremely tight; oil starvation can cause scoring on the rotor surfaces, compromising the original precision fit and clearance.

Insufficient cooling triggers a high-temperature shutdown.

During the compression of air, air compressors generate substantial heat, and the lubricating oil, circulating throughout the system, plays a critical role in dissipating this heat. Without adequate lubrication to provide cooling, the temperature inside the compression chamber can rise rapidly.

When the exhaust temperature exceeds the equipment’s preset safety threshold, the temperature control system triggers an alarm and initiates an emergency shutdown. Prolonged operation at elevated temperatures not only accelerates the oxidation and degradation of the lubricating oil but also leads to premature aging of seals and a reduced service life of electrical components.

Decreased sealing performance and reduced displacement

In screw-type and other types of air compressors, lubricating oil also serves to seal the clearances within the compression chamber. The oil film effectively fills the minute gaps between the rotors and the housing, as well as between the rotors themselves, thereby preventing leakage of the compressed gas.

If no lubricant is added, the internal seals will fail, leading to severe internal leakage of the compressed gas within the chamber. This directly results in a substantial drop in the equipment’s volumetric efficiency and a noticeable reduction in actual air delivery, rendering it unable to meet the production line’s air‑consumption requirements while also causing significant energy waste.

Host system freeze and equipment scrapping risks

This is the most severe consequence of an air compressor operating without sufficient oil. As wear intensifies, temperatures spiral out of control, and metal debris accumulates throughout the system, the internal operating resistance of the compressor’s main unit increases exponentially.

In extreme cases, the rotor may become completely seized due to thermal expansion and mechanical binding. Once the prime mover seizes, the motor can overheat and burn out, potentially even causing the drive shaft to fracture. At this point, the prime mover typically requires a major overhaul or outright replacement, imposing substantial repair costs and production downtime on the enterprise.

Daily Maintenance and Oil-Use Recommendations

To avoid the aforementioned serious consequences, routine scientific maintenance is essential. It is recommended to implement the following measures in daily operations:

• Regularly check the oil level:After the equipment has been shut down and the system has been depressurized, check the lubricating oil level using the sight glass to ensure it is within the normal range.
• Replace the lubricant on schedule:Replace the lubricating oil in accordance with the operating hours specified in the equipment manual to prevent oil emulsification or carbon buildup.
• Monitoring operating parameters:Closely monitor the exhaust temperature and oil pressure readings on the control panel, and immediately shut down the unit for troubleshooting if any abnormal fluctuations are detected.
• Select compliant fuels:It is mandatory to use a dedicated lubricant that meets the equipment manufacturer’s specifications; mixing oils of different brands or grades is strictly prohibited.