The working principle of the oil filter is: during the operation of the engine, with the operation of the oil pump, the oil with impurities enters the oil filter from the oil inlet on the oil filter base plate assembly, and then passes through the check valve to the outside of the filter paper for filtering. Under the action of the oil pressure, the oil continuously passes through the filter paper and enters the central pipe, while the impurities in the oil remain on the filter paper.

More information is as follows:
1. The oil filter is located in the engine lubrication system. The upstream of the oil filter is the oil pump, and the downstream is the various parts in the engine that need lubrication.
2. The function of the oil filter is to filter the harmful impurities in the oil, and supply the crankshaft, connecting rod, camshaft, supercharger, piston ring and other moving parts with clean oil to play the role of lubrication, cooling and cleaning, thus extending the service life of these parts.
3. The oil filter is mainly composed of filter paper and housing, as well as sealing ring, support spring, bypass valve and other auxiliary components. From the appearance, you can see the oil filter as a whole, but you can't see the filter paper, bypass valve and other parts.
4. There are two types of oil filters in reality: primary filter and secondary filter. The lubrication system also has two filtration modes: full-flow and split flow. The primary oil filter and the secondary oil filter correspond to the full flow type and the split flow type respectively.