Oil filter

Oil filter

The oil filter is located in the engine lubrication system. Its upstream is the oil pump, downstream is the engine in the need of lubrication parts. Its role is to filter out harmful impurities from the oil pan oil, to clean oil supply crankshaft, connecting rod, camshaft, supercharger, piston ring and other motion pairs, lubrication, cooling, cleaning, so as to extend the life of these parts.
species
Centrifugal oil filter has a rotor sleeve on a shaft, and has two spray nozzle opposite direction, when the oil into the rotor out of the nozzle, the rotor will rotate quickly, so that the oil in the rotor body is clean, the impurities in the oil are centrifugal thrown to the inner wall of the rotor, the oil flow out of the nozzle back to the oil pan. Centrifugal oil filters are characterized by stable performance and no need to replace the filter element. As long as the rotor is removed regularly, the dirt deposited on the rotor wall can be cleaned and reused. Its life span is comparable to that of an engine. Its deficiency lies in the complex structure, high price, bulky, etc., the user has higher technical requirements.
Full-flow oil filters, such as the previously mentioned interchangeable, rotary, shunt centrifugal, etc., filter all the oil entering the system. The shunt filter only filters 5%-10% of the oil supplied by the oil pump. Shunt oil filter is fine filter, it is generally used with full flow. Most of the engines with small power only use full-flow filter, while the diesel engines with large power mostly use full-flow plus shunt filter devices.
shortcomings
There are two major shortcomings, and the new product makes up for the shortcomings, so it is necessary to use the new product strong magnetic oil filter.
One disadvantage: filter 60% of the impurities in the oil, low filtration efficiency;
This is because the existing oil filter relies on a single paper filter hole to intercept and filter out harmful impurities in the oil. The smaller the pores of the filter paper, the better the filtration effect, but the worse the oil through the ability. In order to solve the problem that not only the smallest particles of impurities can be filtered out on the same filter paper microhole, but also the sufficient amount of engine oil can pass through the microhole. According to the filter branch of the National Internal Combustion Engine Industry Association, the best oil filter on the market can only be designed to remove 60% of the impurities in the oil, which is the maximum filtration value obtained after thousands of experiments. In actual use, there are 40% harmful impurities, can not be effectively filtered by the paper filter element, in this 40% impurities, because the ferromagnetic impurities are relatively small and hard, so the majority of ferromagnetic impurities, it is the biggest damage to the engine.
Disadvantages 2: Under special conditions, the filtration efficiency is zero;
At the bottom of the paper filter element is provided with a bypass valve, which is designed in order to take into account the engine in cold start oil viscosity or paper filter element is partially blocked or completely blocked, to ensure that the oil can cycle back to the engine and the design of direct oil flow channel. When the oil opens the bypass valve under the pressure of the oil pump, the oil that circulates back to the engine through the bypass valve is not only filtered by the paper filter, but also the large particles of impurities that have been filtered out by the paper filter and rushed back to the engine through the bypass valve, bringing continuous secondary wear to the engine. From the above two shortcomings, it can be seen that the impurities larger than or smaller than the paper filter element microholes can not play a permanent filtration effect, only for those impurities equal to the paper filter element microholes and embedded into the paper filter element microholes can play a permanent filtration effect, so the filtration efficiency is very low.
Filter paper requirements
Oil filter to filter paper requirements are higher than the air filter, mainly because the temperature of the oil changes from 0 to 300 degrees, in the severe temperature change, the concentration of oil also changes accordingly, which will affect the filter flow of the oil. The filter paper of a premium oil filter can filter impurities under severe temperature changes to ensure adequate flow.
function
Lubrication system oil filter in order to make the lubrication system oil flow unimpeded, avoid impurities scratch, hair parts surface, oil to the friction surface, must be strictly filtered. In order to achieve satisfactory filtration effect without increasing oil path resistance, the coarse filter is generally connected with the main oil passage in series, and the fine filter is connected with the main oil passage in parallel.
1. Float type oil collecting filter, in order to make the oil pump work well, it is necessary to remove the large particles of impurities in the lubricating oil before entering the oil pump. This task is undertaken by the collecting filter. It is connected to the oil inlet of the oil pump. When the oil pump is working, the oil is sucked from the slit between the cover and the float. After filtering out the coarse impurities through the filter screen, the oil pipe welded on the float enters the oil pump. When the screen is silted up, the suction of the inlet pipe increases, overcomes the strength of the screen and causes the bad mouth to leave the hood, and the oil enters the suction pipe directly from the ring mouth without the filter screen.
2. The coarse filter is connected in series between the oil pump and the main oil passage, so it is also called the full-flow filter, which is used to remove the larger impurities in the oil. It is mainly composed of upper cover, shell, paper filter element and bypass valve. When the engine works, the lubricating oil with pressure is fed into the cavity around the filter element, the larger impurities in the oil are blocked by the paper filter element, and the clean lubricating oil enters the inner cavity of the filter element, and then enters the main oil channel of the cylinder block through the oil outlet.
3, fine filter: its role is to filter out smaller impurities in the lubricating oil, usually with the main oil channel in parallel, there are two kinds of centrifugal and paper plate.
4, the structure of the centrifugal fine filter: the hollow shaft is fixed on the shell, the rotor body and the end sleeve are integrated, located on the thrust bearing, can rotate freely around the rotor shaft. The compression nut fastens the rotor cover to the rotor body, which is pressed by a spring to limit the axial movement of the rotor. Under the rotor are two nozzles that are opposite each other. When the engine is running, a small part of the oil is pumped out from the oil pump and into the filter through the oil port. When the oil pressure is less 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, the pressure limiting valve gradually opens, and the oil is ejects from the oil outlet hole through the center hole of the rotor shaft. Then through the oil hole into the rotor, and out of the two nozzles, so that the jet reaction force is to push the rotary hand. When the oil pressure rises to 294 kpa, the rotor speed can reach 5000r/min or more. The proportion of impurities in the lubricating oil in the rotor cavity is larger than that of the lubricating oil. Under the action of 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 jets out, and the lubricating oil flows back to the lower crankcase.