What is a common reason for the failure of lubricated bearings?

A primary factor contributing to the failure of lubricated bearings is that various detrimental conditions can occur, making the correct answer inclusive of all listed factors. Each choice highlights a common issue that can lead to premature bearing failure.

Excessive heat can degrade the lubricant and lead to thermal expansion issues in the bearing material itself. This heat can come from overloading the bearing, insufficient lubrication, or environmental factors, causing wear and potentially catastrophic failure.

Insufficient lubrication is critical because it means there isn't enough protective oil film to separate the bearing surfaces. This can lead to increased friction, wear, overheating, and ultimately bearing failure. Proper lubrication is essential for minimizing direct metal-to-metal contact.

Contaminated oil also poses significant risks. Contaminants such as dirt, water, or metal particles can compromise the integrity of the oil and the surfaces of the bearing. This contamination can lead to accelerated wear, corrosion, and greatly reduced lifespan of the bearing.

These factors are interconnected and can compound the effects on bearing performance, making it clear that the answer encompasses all of these crucial issues. Understanding this holistic view helps in maintaining proper lubrication practices and implementing preventive measures in machinery maintenance.