Answer: The lubrication principle of lubricating oil is to reduce friction. The so-called friction refers to the existence of a relative contact surface when two relatively moving surfaces undergo relative displacement under the action of external force, which is called the friction surface. There are many types of friction phenomena, including external friction, internal friction, sliding friction, rolling friction, dry friction, boundary lubrication friction, fluid lubrication friction, mixed lubrication friction, etc. The apparent phenomena caused by friction include high temperature, high pressure, noise, wear, etc. Among them, wear is the most harmful, and wear includes adhesive wear, abrasive wear, corrosive wear, surface fatigue wear, etc., which directly affects the normal operation of mechanical equipment and even fails.
The role of lubricating oil is to form a protective film between the two friction pairs to avoid direct contact between metal and metal, thereby buffering the friction force, playing a lubricating role, reducing wear, and allowing the machine to operate normally. This protective film can be a physical adsorption film, a chemical adsorption film or an oxide film. The thickness and strength of the film directly affect the lubrication effect.
The lubricating effect of ordinary lubricating oil is mainly to form an oil film between friction surfaces for protection. The lubricating theory of lubricating oil relies on additives to form an adsorption film on the friction surfaces for protection. The base oil itself only acts as a carrier for additives and a seal between the friction surfaces. The lubricating effect of the oil film has been relegated to a secondary position.
