The oil filter in the lubrication system in order to make the lubrication system oil flow through unobstructed, to avoid scratches and burrs on the surface of the parts, the oil must be strictly filtered before being sent to the friction surface. In order to achieve a satisfactory filtration effect without increasing the resistance of the oil circuit, a coarse filter is generally connected in series with the main oil passage, and a fine filter is connected in parallel with the main oil passage.
1. Float oil filter, in order to make the oil pump work well, the large particles of impurities in the lubricant must be removed before entering the oil pump. This task is assumed by the filter. It is connected to the oil inlet of the oil pump. When the oil pump is working, the oil is sucked in through the slit between the cover and the float. After filtering out coarse impurities through the filter screen, it enters the oil pump through the oil pipe welded to the float. When the filter is blocked, the suction of the oil inlet pipe increases, and the bad port is overcome by the filter's strength to leave the cover, and the oil directly enters the suction pipe from the ring port without passing through the filter.
2. The coarse filter is connected in series between the oil pump and the main oil passage, so it is also called a full-flow filter, which is used to remove larger impurities in the oil. It is mainly composed of upper cover, housing, paper filter element and bypass valve. When the engine is running, the lubricating oil with pressure is sent around the filter element and into the cavity around the filter element. The larger impurities in the oil are blocked by the paper filter element, and the clean lubricant enters the inner cavity of the filter element and then passes through the oil outlet. Enter the main oil passage of the cylinder block.
3. Fine filter: its role is to filter out the smaller impurities in the lubricating oil, usually in parallel with the main oil passage, there are two types of centrifugal and cardboard.
4. The structure of the centrifugal fine filter: the hollow rotating shaft is fixed on the shell, the rotor body and the end sleeve are connected into one body, and it is located on the thrust bearing, which can rotate freely about the rotor shaft. The compression nut fastens the rotor cover and the rotor body, and the upper part is compressed by a spring to limit the axial movement of the rotor. The lower part of the rotor is equipped with two nozzles which are opposite to each other. When the engine is running, a small part of the oil is pumped from the oil pump and enters the filter through the oil port. When the oil pressure is lower than 9s kPa, the oil inlet pressure limiting valve is closed, and the fine filter does not work. When the oil pressure exceeds 98 kPa and the pressure limiting valve is gradually opened, the oil is sprayed out from the oil hole through the center hole of the rotor shaft. Then it enters the rotor body through the oil hole and sprays out from the two nozzles, so the reaction force of the spray pushes the hand to rotate. When the oil pressure rises to 294 kPa, the rotation speed of the rotor can reach more than 5000r / min. The proportion of impurities in the lubricating oil in the rotor cavity is greater than that of the lubricating oil. Under the action of the rotating centrifugal force, it is thrown to the rotor wall, and Attached to the wall. The clean lubricating oil at the center enters the two nozzles from the center and continuously sprays outwards, and the lubricating oil flowing back flows to the lower crankcase.