1. Pressure Lubrication System:
Oil Pump: In most engines, an oil pump driven by the engine's rotation draws oil from the oil sump or oil pan, which serves as the oil reservoir.
Oil Filter: Before entering the engine's lubrication system, the oil passes through an oil filter to remove contaminants and particles.
Oil Pressure: The oil pump generates oil pressure, which is essential for proper lubrication. Pressure is regulated by a pressure relief valve to prevent excessive pressure buildup.
Oil Galleries and Passages: The pressurized oil is distributed throughout the engine through oil galleries and passages.
Oil Jets: In some engines, oil jets are used to direct a concentrated stream of oil onto specific bearing surfaces, ensuring adequate lubrication.
2. Splash Lubrication:
Oil Dipstick: In engines using splash lubrication, the crankshaft dips into an oil reservoir located in the crankcase. As the crankshaft rotates, it splashes oil onto the bearings and other moving parts.
Splash Tray: A splash tray or deflector is used to help distribute the oil more effectively.
3. Mist Lubrication:
Oil Mist: Some engines use a mist lubrication system, where oil is atomized into a fine mist and circulated through the engine. The oil mist lubricates the bearings and other components as it condenses on the surfaces.
4. Full-Flow Lubrication:
In full-flow lubrication, all the oil from the oil pump passes through the oil filter before reaching the bearings. The oil carries away contaminants and metal particles, ensuring cleaner lubrication.
5. Supplementary Lubrication:
Some engines may have additional localized lubrication systems for critical components like turbochargers or variable valve timing mechanisms. These systems can use separate oil pumps or dedicated oil passages for specific lubrication needs.
Adequate lubrication is vital for minimizing friction and wear between the crankshaft bearings and the crankshaft journal surfaces. The effectiveness of the lubrication system is influenced by factors such as oil viscosity, oil quality, oil temperature, and the design of the lubrication passages. Regular oil changes and maintenance are crucial to ensure the continued health and performance of the engine.
