The friction surface of the relative moving parts is covered with a thin lubricating oil film, which makes the surface of the parts separated by a layer of oil film, thus turning the mechanical dry friction into liquid friction.
This can reduce friction resistance, reduce wear and tear of engine parts, increase efficiency and prolong the service life of diesel engine. Therefore, the application of oil in the reliability, durability and economy of diesel engine has a great impact.
The Function of Oil
Lubrication
When the engine works, the parts move relative to each other. By lubricating the oil, a layer of oil film is formed between the moving parts, which can reduce the wear of the parts inside the engine. It not only improves the mechanical efficiency, but also prolongs the working life of the engine.
Cooling and heat dissipation
In lubrication process, oil can take away the excess heat generated by friction between engine parts, which plays an indirect role in heat dissipation and avoids the burning of engine parts due to excessive temperature.
Cleaning effect
During the repeated relative motion of engine components, some metal debris and carbon particles will be produced due to friction. Oil can remove these impurities, prevent particle wear, and aggravate the aging and deformation of engine components.
Anti-corrosion and Anti-rust Function
Oil evenly distributes on the surface of parts during operation. Additives with anti-rust effect in the oil will form an adsorption layer on the metal surface, which can isolate the oil from air, water and gas directly, avoid oxidation and rust of parts, and reduce corrosive wear and tear.
Sealing effect
All the oil has a certain physical viscosity. When it is adhered to the surface of the parts, it can isolate the different working environment in the combustion chamber and have a good sealing effect. In addition, diesel oil produces high-pressure gas when it is compressed and ignited in the combustion chamber of the engine, which drives the piston to work. Oil can seal the gap between piston and valve, reduce pressure loss and improve mechanical efficiency.
Shock absorption
When the starting, accelerating or bearing load of diesel engine changes greatly, the piston pin, crankshaft bush and connecting rod end and other parts have to bear drastic changes caused by vibration. The oil film formed by proper viscous lubricating oil covering these parts can absorb part of the energy of impact load, reduce the negative impact of vibration on the normal operation of the engine, and play a role of cushioning load.