What are general lubrication objectives and typical schedules for bearings and gears?

• A. Reduce friction and wear, protect against corrosion, maintain cleanliness; follow manufacturer intervals and lubricant type/specifics.
• B. Lubrication is unnecessary for most bearings.
• C. Lubrication is only needed when gears squeal.
• D. Lubrication can use any lubricant arbitrarily.

Answer: (C)

Lubrication aims to protect moving parts by forming a film that reduces friction and wear, preventing metal-to-metal contacts. This film also helps transfer heat away from bearings and gears, carries away contaminants, and protects surfaces from corrosion, while supporting overall cleanliness inside the system. A proper lubrication schedule goes beyond just “sparing some oil in.” It follows the manufacturer’s intervals and uses the lubricant type and specifications exactly as recommended, with adjustments for how the machine is operated (load, speed, temperature, duty cycle, and environmental contamination). Regular checks on lubricant condition (level, viscosity, contamination, and degradation) and timely re‑application or replacement are key to sustaining performance and life for both bearings and gears.

Why the other ideas don’t fit: lubrication isn’t unnecessary for most bearings, even under light or routine use; it’s a preventive measure that reduces wear and extends life. It isn’t only needed when squealing occurs—noise can indicate lubrication problems, but waiting for sound is too late for preventive maintenance. And you can’t use any lubricant arbitrarily—the wrong viscosity, additives, or compatibility can cause poor lubrication, chemical damage, or faster wear, so selection must align with system design and operating conditions.