Oil filter, also known as machine filter, or oil grid, is located in the engine lubrication system. The upstream of the filter is the oil pump, and the downstream is the parts that need lubrication in the engine. Oil filters can be divided into full flow type and split flow type. Full-flow filters are connected in series between the oil pump and the main oil passage, so that all lubricants entering the main oil passage can be filtered. The shunt cleaner is connected in parallel with the main oil passage, and only part of the lubricating oil from the oil pump is filtered.
In the process of engine operation, metal debris, dust, carbon deposit oxidized at high temperature and colloidal precipitate, water and so on are continuously mixed with lubricating oil. The function of oil filter is to filter out these mechanical impurities and colloids, keep the lubricating oil clean and extend its service life. Oil filters should have strong filtering ability, low flow resistance and long service life. In general lubrication system, several filters with different filter capacity – collector, coarse filter and fine filter are installed, which are connected in parallel or in series in the main oil passage respectively. (Full-flow filters are connected in series with main oil passages, and all lubricants are filtered by filters when the engine works; shunt filters are connected in parallel with them). The coarse filter is connected in series in the main oil pipeline and the fine filter is connected in parallel in the main oil pipeline. Modern car engines generally only have a filter collector and a full-flow oil filter. Coarse filters are used to remove impurities with particle size over 0.05 mm, while fine filters are used to remove fine impurities with particle size over 0.001 mm.
Function of Machine Filtration
Machine filter filters harmful impurities in oil from oil pan to supply crankshaft, connecting rod, camshaft, supercharger, piston ring and other motion pairs with clean oil, which plays the role of lubrication, cooling and cleaning, thus prolonging the life of these parts.
Structure of Machine Filter
According to the structure, the machine filter can be divided into replaceable type, rotary type and centrifugal type. According to the arrangement in the system, it can be divided into full-flow type and split-flow type. The filter materials used in machine filtering are filter paper, felt, metal mesh, nonwovens, etc.
Technical characteristics
Filter paper: Oil filters require higher filter paper than air filters, mainly because the temperature of oil varies from 0 to 300 degrees. Under drastic temperature changes, the concentration of oil also changes correspondingly, which will affect the filtration flow of oil. High quality oil filter paper should be able to filter impurities under drastic temperature changes, while ensuring adequate flow.
Rubber Seal Ring: High-quality oil filter seal ring is made of special rubber to ensure 100% oil leakage.
Backflow Suppression Valve: Only high quality oil filters are available. When the engine goes out, it prevents the oil filter from drying out; when the engine is re-ignited, it immediately generates pressure and supplies oil to lubricate the engine. (Also known as check valves)
Overflow valves: Only high-quality oil filters are available. When the external temperature drops to a certain value or when the oil filter exceeds its normal service life, the relief valve will be opened under special pressure, allowing the unfiltered oil to flow directly into the engine. In spite of this, impurities in the oil will enter the engine together, but the damage is much smaller than that caused by the absence of oil in the engine. So the relief valve is the key to protect the engine in emergency. (Also known as bypass valves)
Replacement cycle
Installation:
A) Drain or suck up old oil
B) Unscrew the fixing screw and remove the old oil filter
C) Apply a layer of oil to the sealing ring of the new oil filter
D) Install a new oil filter and tighten the fixing screw
Suggested replacement cycle: cars and commercial vehicles are replaced once every six months
Post time: Dec-21-2018