The oil filter is divided into full flow and distributary. Full flow filter is connected in series between the pump and the main oil channel, it can filter into the main oil all lubricating oil. The shunt cleaning device is in parallel with the main oil channel, and only part of the lubricating oil is sent out by the filter oil pump. During the working process of the engine, the metal debris, dust, the carbon deposited at the high temperature, and the gelatinous sediment and water are constantly mixed with the lubricating oil. The function of the oil filter is to filter out the mechanical impurities and gelatin, to keep the lubricating oil clean and prolong the use period. Oil filter should have filtering ability, small flow resistance, long service life and other performance. The lubrication system is generally using several different filtering capacity of filter - filter set, coarse filter and fine filter, respectively in parallel or in series in the main oil passage. (in series with the main oil passage is called full flow filter, engine lubricating oil by filter; and parallel call shunt filter). The coarse filter is in series in the main oil channel, which is full flow type, and the fine filter is parallel to the main oil channel, which is a shunt type. The modern car engine is generally only equipped with a filter and a full flow oil filter. The coarse filter is used to filter out the impurities with the particle size of more than 0.05mm, and the fine filter is used to filter the fine impurities with the particle size of more than 0.001mm. The technical features of the oil filter:
The filter paper: oil filter of filter paper is higher than the air cleaner, mainly because the oil temperature changes from 0 to 300 degrees ranging in temperature change dramatically, the oil concentration change, which will affect the flow of filtered oil. The filter paper of the high quality oil filter should be able to filter the impurities and ensure enough flow at the same time.
Rubber sealing ring: the filter seal ring of high quality oil is made of special rubber to guarantee 100% no oil leakage.
Reflux suppression valve: only the high quality oil filter is available. When the engine is flameout, it prevents the oil filter from drying; when the engine is re - ignited, it produces pressure immediately and supplies the oil to lubricate the engine. (also called back valve)
Overflow valve: only the high quality oil filter is available. When the external temperature drops to a specific value or when the oil filter exceeds normal service life, the relief valve will open under special pressure and let the unfiltered oil flow directly into the engine. In spite of this, impurities in the oil will enter the engine together, but this damage is much smaller than that caused by engine oil. Therefore, the overflow valve is the key to the protection of the engine in an emergency. (also known as a bypass valve)
