Question 42 1AE01 - First Assistant Engineer

The Correct Answer is C **Why option C ("Bimonthly") is correct:** In machinery utilizing an oiling ring (also known as a sling ring or oil ring) for lubrication, the ring dips into an oil sump located below the bearing. As the bearing shaft rotates, the oiling ring turns, picking up oil and depositing it onto the shaft for distribution across the bearing surface. Over time, impurities such as metallic wear particles (swarf), dust, condensation, and oxidation byproducts settle at the bottom of the oil sump. Allowing these impurities to accumulate excessively increases the risk of them being re-circulated by the oiling ring into the bearing surfaces, causing abrasive wear and reducing bearing life. A **bimonthly** (every two months) draining and cleaning schedule is a standard and practical interval in industrial maintenance practices for this type of system. This frequency is short enough to prevent critical accumulation of harmful sludge and contaminants, yet long enough to be manageable within a standard preventive maintenance program. **Why the other options are incorrect:** * **A) Every round:** This phrase is unclear in a time context, possibly implying every operational cycle, but if interpreted as very frequent (e.g., daily or multiple times a day), it would be grossly impractical and unnecessary for monitoring static sump impurities, which settle slowly. * **B) Daily:** Draining the sump daily is excessive. While it would ensure very clean oil, the process is time-consuming, wastes labor, and requires frequent replenishment of oil, offering little practical benefit over a longer interval since impurities take time to accumulate and settle out of suspension. * **D) Annually:** Draining the sump only once a year is generally insufficient. Impurities and sludge can accumulate significantly over 12 months, potentially leading to critical abrasive wear, clogging of the oil return passages, and premature bearing failure long before the scheduled annual drain. This interval poses a high risk to equipment longevity.