Oil filter is in the lube system of the engine. Its upstream is oil pump, downstream is every parts which need lubricate in the engine. It can filter the bad impurities from oil pan, and surpport clean oil to crankshaft, connecting rod, camshaft, supercharger, piston ring, etc. It play a role in lubrication, cooling and cleaning, and extend their life. According to the structure of oil filter, it has removable, spin –on and centrifugal type. According to the arrangement in system, it has full flow and shunt type. There are many materials of oil filter, such as filter paper, felt, metal mesh and nonwoven fabric, etc.

Generaly speaking, every parts in engine all need lubcriated by oil to work normally. But when parts work, there are many metal debris, incoming, oxidizing carbon at high tempurature and a part of water vapor can mix in the oil. The use of oil will be reduced by time, even can affect engine work.
Therefore, the function of oil filter is reflected at this time.