Oilers/Plant Tenders (HHC) Civil Service Practice Exam

In gear lubrication, immersion of gear teeth has what effect?

1. Reduces wear on the gears

2. Causes a sudden increase in lubricant temperature

3. Increases the lubricant viscosity

4. Prevents metal fatigue

The correct answer is: Causes a sudden increase in lubricant temperature

In the context of gear lubrication, immersion of gear teeth primarily reduces wear on the gears. When gears are fully immersed in lubricant, it creates a continuous supply of fluid that adequately covers the surfaces of the gear teeth. This reduces direct metal-to-metal contact, thereby minimizing friction and wear during operation. The presence of a sufficient lubricant film is crucial because it helps in dissipating heat generated from friction, distributing it away from the gear surfaces. It also helps in sealing out contaminants and moisture, ensuring that the gears operate smoothly and efficiently for longer periods. Considering the other options, a sudden increase in lubricant temperature isn't typically a direct result of immersion; rather, effective lubrication tends to manage temperatures effectively. Increasing the viscosity of the lubricant would not facilitate better lubrication directly and is contingent upon the lubricant's properties rather than the immersion itself. Additionally, while proper lubrication can help mitigate the effects of metal fatigue, immersion alone does not directly prevent it; metal fatigue is influenced by multiple factors including load cycles and materials. Thus, immersion primarily aids in wear reduction for the gears.