Which of the following is NOT a standard gear lubrication method?

• A. Bath Lubrication
• B. Splash Lubrication
• C. Vapor Deposition
• D. Directed Flow

Answer: (C)

When lubricant is applied to gears, the goal is to keep a reliable film between the teeth, remove heat, and reduce wear. Bath lubrication submerges the gears in an oil pool so the film is automatically present as they rotate. Splash lubrication uses the motion of gears or a dipper to fling oil onto the gears from a reservoir, providing lubrication without a full immersion. Directed flow pumps and guides oil to the gear mesh in a controlled way, giving precise film thickness and cooling.

Vapor deposition, by contrast, is a coating process that places a lubricant or lubricant-like film onto surfaces as a vapor or thin coating. It isn’t used as a routine, reliable method to lubricate gear meshes under typical operating loads and speeds, where continuous replenishment and heat removal are needed. So it isn’t considered a standard gear lubrication method.