Which quality is essential for oil film lubrication?

The essential quality for oil film lubrication is to separate moving surfaces. This characteristic is crucial because the primary purpose of oil film lubrication is to create a barrier between two surfaces that are in motion relative to each other. By forming a thin layer of oil, the lubrication minimizes direct contact between the surfaces, thereby preventing wear and tear, which can lead to damage over time.

In addition to separating surfaces, oil film lubrication also plays a role in reducing friction, enhancing thermal conductivity, and involving some level of oxidation prevention, but the primary and most critical function is the separation of moving components. This separation is what allows for smoother operation and greater efficiency in machinery and engines, which is vital for prolonged equipment life and reliability.