Oil filter

Oil filter
 
Oil filter
The oil filter is used to remove dust, metal particles, carbon deposits, soot particles and other impurities in the oil to protect the engine.
 
The oil filter is divided into full-flow type and split-flow type. The full-flow filter is connected in series between the oil pump and the main oil passage, so it can filter all the lubricating oil entering the main oil passage. The split-flow cleaner is connected in parallel with the main oil passage to filter only part of the lubricating oil sent by the oil pump.
 
 
The role of oil filter
Under normal circumstances, various parts in the engine are lubricated by oil to achieve normal operation, but the metal chips, dust, carbon deposits oxidized at high temperature and some water vapor will be continuously mixed in when the parts are running. In the oil, the service life of the oil will be reduced if the time is long, and it may affect the normal operation of the engine in severe cases.
Therefore, the role of the oil filter at this time is reflected. Simply put, the main function of the oil filter is to filter most of the impurities in the oil, keep the standby oil clean, and extend its normal service life. In addition, the oil filter should also have the performance of strong filtering capacity, low flow resistance, and long service life.
 
When the engine is working, metal wear debris, dust, carbon deposits oxidized at high temperatures, colloidal deposits, and water are constantly mixed into the lubricant. The function of the oil filter is to filter out these mechanical impurities and gums, to keep the lubricating oil clean and extend its service life. The oil filter should have strong filtering capacity, low flow resistance, and long service life. Generally, several filters with different filtering capacity are installed in the lubrication system-filter collector, coarse filter and fine filter, which are connected in parallel or in series in the main oil passage respectively. (The one connected in series with the main oil passage is called a full-flow filter. When the engine is working, all lubricating oil is filtered by the filter; the one connected in parallel is called a split-flow filter). Among them, the coarse filter one is connected in series in the main oil passage, which is a full flow type; the fine filter is connected in parallel in the main oil passage, which is a split flow type. Generally, only a filter and a full-flow oil filter are installed on modern car engines. The coarse filter filters out impurities with a particle size of 0.05mm or more in the oil, and the fine filter is used to filter out fine impurities with a particle size of 0.001mm or more.
 
 
Technical characteristics
●Filter paper Oil filters have higher requirements for filter paper than air filters, mainly because the temperature of the oil varies from 0 to 300 degrees. Under severe temperature changes, the concentration of the oil changes accordingly. It will affect the filtering flow of the oil. The filter paper of a high-quality oil filter should be able to filter impurities under severe temperature changes while ensuring sufficient flow.
●Rubber sealing ring The filter sealing ring of high-quality oil is made of special rubber to ensure 100% oil leakage.
●Backflow suppression valve only available in high-quality oil filters. When the engine is stopped, it can prevent the oil filter from drying out; when the engine is re-ignited, it immediately generates pressure to supply oil to lubricate the engine. (Also known as check valve)
●Overflow valve only available in high-quality oil filters. When the external temperature drops to a certain value or when the oil filter exceeds the normal service life, the overflow valve will open under special pressure, allowing unfiltered oil to flow directly into the engine. Even so, the impurities in the oil will enter the engine together, but the damage is much smaller than the damage caused by the absence of oil in the engine. Therefore, the overflow valve is the key to protect the engine in an emergency. (Also known as bypass valve)
 
 
Oil filter replacement cycle
●Installation
a) Drain or suck up old engine oil
b) Loosen the fixing screws and remove the old oil filter
c) Apply a layer of oil on the sealing ring of the new oil filter
d) Install the new oil filter and tighten the fixing screws
●Recommended replacement cycle cars and commercial vehicles are replaced every six months
 
 
Automotive requirements for oil filters
Filter precision, filter out all particles 30 um,
Reduce particles that enter the lubrication gap and cause wear ( 3 um-30 um)
The oil flow rate corresponds to the engine oil demand.
Long replacement cycle, at least longer than the oil life (km, time)
The filtering accuracy meets the requirements of protecting the engine and reducing wear.
Large ash capacity, suitable for harsh environments.
It can adapt to higher oil temperature and corrosive environment.
When filtering the oil, the lower the pressure difference, the better, to ensure that the oil can pass smoothly.
 
 
Disadvantages of ordinary oil filters
The oil filter on the market has 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.
Disadvantage 1 It can only filter out 60% of impurities in the oil, and the filtration efficiency is low;
This is because the current oil filter relies on a single paper filter hole to intercept and filter out harmful impurities in the oil. The smaller the filter paper, the better the filtering effect, but the worse the oil passing capacity. In order to solve the contradiction that the smallest particles of impurities can be filtered out on the same filter paper micropores, a sufficient amount of engine oil can also be supplied to the engine through the micropores. The filter branch of the National Internal Combustion Engine Industry Association adopts the ISO4548 international standard test method for oil filter filtration efficiency. Tests show that even the best oil filter on the market can only be designed to filter out 60% of impurities in the oil. This is the maximum filtering value obtained after thousands of experiments. In actual use, there are still 40% of harmful impurities that cannot be effectively filtered by the paper filter. Among these 40% of impurities, because ferromagnetic impurities are relatively small and hard, most of them are ferromagnetic impurities, which will damage the engine. maximum.
 
Disadvantage 2 The filtration efficiency is zero under special conditions;
The existing oil filter is equipped with a bypass valve at the bottom of the paper filter element. This is designed to ensure that the oil is partially or completely blocked when the engine is cold-started with high oil viscosity or when the paper filter element is partially or completely blocked. Direct oil flow channel designed for smooth circulation back to the engine. When the oil opens the bypass valve under the pressure of the oil pump, the oil circulating back to the engine through the bypass valve will not only not be filtered by the paper filter element, but also the large particles of impurities that have been filtered out by the paper filter element. It rushes back to the engine through the bypass valve, causing uninterrupted secondary wear to the engine. Therefore, the oil filter used on the market basically plays a filtering role under special conditions, so the filtration efficiency at this time is zero.
It can be seen from the above two shortcomings that the currently used oil filter cannot permanently filter the impurities larger or smaller than the pores of the paper filter element. It can only filter those that are equal to the pores of the paper filter element and are embedded in the paper The impurities in the pores of the filter element play a permanent role in filtering, so the filtering efficiency is extremely low.