underlubrication

Underlubrication is a condition in which moving surfaces in mechanical systems receive insufficient lubrication. It increases friction at contact interfaces and accelerates wear, potentially leading to heat buildup and failure. Underlubrication can occur continuously in poorly maintained systems or intermittently during startup, shutdown, or transient operating conditions.

Causes include low lubricant quantity due to leaks or improper fill levels, degraded or contaminated oil, incorrect viscosity or lubricant type, and blocked or misrouted lubricant passages. It can also arise from design limitations that fail to deliver sufficient film thickness at high loads or speeds, or from startup and shutdown periods when lubrication has not yet reached critical surfaces.

Effects include increased friction, elevated temperatures, accelerated wear and scoring, metal-to-metal contact in extreme cases, and accelerated degradation of the lubricant itself. In bearings, gears, turbines, and engines, underlubrication can lead to reduced efficiency, higher maintenance costs, or sudden failure and downtime.

Detection and monitoring rely on symptoms such as unusual noises, higher oil temperature, and low oil level indications. Oil analysis, wear debris monitoring, and vibration analysis can help diagnose underlubrication and identify the affected components.

Prevention involves proper lubrication planning: selecting appropriate lubricant grade and viscosity, maintaining adequate oil levels, ensuring unobstructed supply lines, filtration, and cooling. Regular inspection of seals, pumps, and lubrication passages; automated lubrication systems with redundancy; and operational practices that minimize startup transients can reduce the risk of underlubrication.