When the engine is running, because the working conditions of the moving parts of the engine are different, the required lubrication strength is also different, so different lubrication methods should be adopted accordingly. Generally speaking, there are four kinds of lubrication methods used in an engine.

　　①压力润滑：压力润滑是利用机油的压力将油输送到各摩擦表面进行强制性润滑，如曲轴主轴承、连杆轴承及凸轮轴轴承等处，需要以一定压力将机油输送到摩擦面的间隙中。

　　Pressure lubrication: Pressure lubrication is the use of oil pressure to transport oil to the friction surface for compulsory lubrication, such as crankshaft main bearings, connecting rod bearings and camshaft bearings, need to be a certain pressure to transport oil to the friction surface clearance.

　　②飞溅润滑：利用曲轴的运转将油从轴承两侧甩出，在曲轴箱内形成许多油滴或油雾，飞溅到各摩擦表面进行润滑，如气缸壁、活塞销等。

　　Splash lubrication: oil is thrown out from both sides of the bearing by crankshaft operation, and many oil droplets or mists are formed in the crankshaft box, splashing onto the friction surfaces for lubrication, such as cylinder wall, piston pin, etc.

　　③综合润滑（压力和飞溅结合）：这种方法广泛应用到现代汽车发动机上。

　　(3) Comprehensive lubrication (combination of pressure and spatter): This method is widely used in modern automotive engines.

　　④润滑脂润滑：发动机的附件如发电机、水泵等轴承均采用润滑脂润滑，需要定期加注或清洗更换。

　　(4) Grease lubrication: Engine accessories such as generators, water pumps and other bearings are lubricated with grease, which needs regular filling or cleaning and replacement.