Detailed explanation of supporting technology of t

2022-10-01
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Detailed explanation of supporting technology of oil filter

the supporting technology of filter has the nature of marginal discipline in a small range, so it is easy to be ignored. In practice, we can often see such a phenomenon: the well-designed filter installed on the host can not maximize its due role. The host user is not satisfied with the performance of the selected filter. This is the problem of improper filter matching. This paper attempts to discuss the selection, design, installation and use of oil filter from the perspective of matching. The topics involved include the following eleven items:

1 Flow through the oil filter

2. Service conditions of internal combustion engine

3. Quality of lubricating oil

4. Use level of internal combustion engine operators

5. The installation position of oil filter on the internal combustion engine

6. Connection between oil filter and oil radiator

7. Determination of opening pressure of bypass valve

8. Application of maintenance indicators

9. Structure of composite oil filter

10. Large flow oil filter

11. Pressure regulating valve problem

the oil filter is located in the lubrication system of the internal combustion engine. Upstream is the oil pump. Downstream is the main oil passage. With the development of modern internal combustion engine towards high speed and high output, the capacity of lubrication system is expanded and the oil temperature is increased. The structure is complicated by the widespread use of oil radiators and piston oil injection cooling devices. At the same time, the quality of lubricating oil is improved, and the types of additives are increased, which puts forward new requirements for the filtration function of the filter. All these give new content to the matching technology of oil filter

1. There are four bases for determining the matching flow of the oil filter through the flow of the oil filter:

a. the filter flow data required by the user

b. type, power and strengthening degree of supporting internal combustion engine

c. oil pump flow

d. main oil passage flow

the empirical formula used to calculate the main oil passage flow from the internal combustion engine power is as follows:

q=( υ) L/hphr (gasoline engine)

q= () l/hphr (diesel engine)

the low value is taken for light load service conditions. Take the higher value for heavy load service conditions. In the heavy load belt, the supercharged can be increased by another%

if the user provides the design flow of the oil pump or the measured flow of the new oil pump, the filter flow can be% of the oil pump flow value. Because the oil pump designer has considered that the oil pump will gradually wear out and the flow will gradually decrease during use. In order to meet the needs of the host, it must increase the design flow

some users also provide the filter designer with the design flow of the main oil passage of the internal combustion engine. In this case, the flow value of the filter should be set at 1% of the design flow of the main oil passage 0 times. This is because with the normal wear and tear of the internal combustion engine, the flow rate of the main oil passage will increase correspondingly to maintain the normal oil pressure

as for the flow of the shunt filter, take 5 ~ 10% of the flow of the full flow filter, or take it as a degree that all the engine oil in the engine oil pan can be filtered once every 10 minutes or so

2. Service conditions of internal combustion engines

the operating conditions of internal combustion engines are diverse. From city cars to agricultural trucks. From indoor power generation to oilfield engineering machinery. The use conditions vary greatly. In terms of load, there are light load, medium load, heavy load and extra heavy load. In terms of the duration of load action. There are continuous load and intermittent load. These different working conditions affect the changes of oil temperature and oil pressure in the lubrication system, that is, the working conditions of the filter. At the same time, it also determines the characteristics of the filter material and the size of the filter area

continuous heavy-duty diesel engine represents the most load-bearing service conditions. The oil filter not only needs to withstand high temperature for a long time (120 ~ 150 ℃), but also has to withstand the impact of millions of pressure shocks. Therefore, the filter structure and filter material should have sufficient mechanical strength. The seal and filter element adhesive must be able to withstand the attack of high-temperature engine oil

for the service conditions of variable load, if the proportion of river load operation time is very small, like light vehicles. The load of the filter can be set at 50 ~ 60% of the maximum load at the highest engine speed. This will not make the size of the filter too large

although some internal combustion engines also operate continuously at full load, the environmental conditions are good and the level of use and management is high. Such as the power generation equipment in the machine room and the power of large ships. The oil filter with perfect performance and more complex structure or more difficult maintenance can be used. Or when the installation space allows, you can also increase the filtering area to prolong the maintenance cycle and save management costs

there are also some safety rope/safety belt detection and testing machines produced by Shandong Sida high tech factory with special service conditions, which are specially used for safety belt tension experiments, such as the power of combine harvesters. It is only used continuously for more than ten days every year. But in these ten days, parking accidents are not allowed. The engine oil filter matched with this kind of machinery must have excellent short-term reliability. It is better to make some sacrifices in other performance indicators if it can persist to the end during the operation period of the harvester. The operation of replacing the filter element should also be very simple, and the problem should be solved in a few minutes

the above are several typical examples of internal combustion engine service conditions. The filter supporting designer must carefully and comprehensively examine and analyze the specific operating conditions of the host. Select the structure that best meets the service conditions. Queued out filter performance in the face of the special conditions, the filter can adapt to any service conditions. Even if we try to do it, it is either extremely expensive, or the structure is extremely complex, or the volume and weight are too large and heavy to be accepted by users

3. Quality of lubricating oil

years of experience have proved that even a very good oil filter will fail in use regardless of the quality of internal combustion engine lubricating oil. Indeed, high-quality lubricants have been used in some internal combustion engines. Users are no strangers to API's SD, Se, SFCC and CD grade lubricants. These oils have good anti-oxidation stability and floating diffusivity. Microporous filter paper filter element has a good effect in this kind of oil, but it should also be noted that many users still use low-quality or even inferior oil in rural and remote areas. There are many impurities in the oil, with poor oxidation resistance and no cleaning effect. It is easy to produce agglomerates and asphaltenes in the process of use, resulting in the blockage of the filter element. Shortening the service or maintenance life of the filter is particularly detrimental to the filter element made of microporous filter paper. In view of this situation, the filter designer should take some measures: either add a metal pre filter element before the paper filter element, or use a composite filter element, or connect a centrifugal filter in parallel in the lubrication system

however, it should be pointed out to users that the maintenance and service costs of the filtration system after the above measures are adopted should be increased. If the comprehensive technical and economic effects of different grades of lubricants are analyzed in detail, the conclusion must be conducive to high-quality lubricants

4. The technical level of the internal combustion engine operator

the oil filter is a component that needs frequent maintenance or replacement, and the cycle is about 5000 ~ 10000 kilometers, or 150 ~ 250 hours. Therefore, the technical level of internal combustion engine use and management will affect the decision-making of which structure filter to choose. Here are three ways to use and maintain filters to illustrate this problem

the rotary filter is the easiest to replace. Unscrew an old one with hands or tools, and then screw on a new one with hands, which should be completed in accordance with the rules of the relevant skill documents. There are no other parts to be disassembled. Even people who are not familiar with the structure of the oil filter can do this work well. This is one of the advantages that spin on filter can be quickly popularized. However, one of the prerequisites for the use of spin on filters is that the spare parts of filters should be sufficient and can be purchased anytime, anywhere

in sharp contrast to the spin on filter is the centrifugal filter. Its filtering effect is superior, there are no parts that need to be replaced, and it can almost have the same service life as the engine. But it has a high-speed rotating rotor (5000 ~ 8000r/min). Reassemble after finishing. Such work must have a fairly high technical level to do well, otherwise the advantages of centrifugal filter will be lost in whole or in part

between the above two structures is the replaceable filter element. Because the filter element components need to be replaced, the supply of filter elements must be guaranteed. At the same time, some parts need to be disassembled and replaced when maintaining and replacing the filter element. Therefore, users are required to have a certain understanding of the structure of the filter and the role of its parts. Otherwise, the wrong or missing installation of a seal ring or a spring or a small tray will invalidate the filter

there are many types of filter structures. The level of users varies greatly. Not all filters that designers and manufacturers think are perfect and excellent can be appreciated by users in practical use. One of the reasons is that the user level does not match the use requirements of the filter

5. Installation position of the oil filter on the internal combustion engine

the filter designer needs to know the installation position of the filter on the main engine in order to deal with the product structure accordingly. The filter can be installed in three ways: upright, horizontal and inverted. The centrifugal filter must be installed upright, and the included angle between the center line of the rotor shaft and the plumb line cannot be greater than 20 ℃. Other types of filters do not have this restriction. The filter installed upside down shall be equipped with one-way valve or check valve to prevent the lubricating oil from draining from the filter after the engine stops. Once drained, the engine will be short of oil when it is started again. At first, it will increase the wear degree of the engine, and at last, it will cause the main engine to jam

the filter designer should also know whether there are other parts and accessories around the installation position or whether they interfere with each other. Therefore, the filter assembly drawing should show the space size required for the replacement or maintenance of the filter, so that the host designer can make appropriate arrangements. During the maintenance of the filter, there will inevitably be oil dripping. Therefore, the filter should not be installed above the motor, electrical appliances and rubber and plastic parts. The shell and parts of other types of centrifugal and inverted filters need to be removed upward during disassembly or maintenance, so it is necessary to avoid the exhaust pipe of the host to prevent scalding accidents

6. Connection between oil filter and oil radiator

oil radiator is increasingly used to control the temperature of lubricating oil in modern high-speed internal combustion engines. Therefore, there is the connection mode of filter and radiator. One way is to install the filter before the radiator. The advantage is to let the filtered clean oil enter the radiator, and the channel of the heat dissipation element will not be blocked by impurities in the oil. Another advantage is to let the oil with higher temperature pass through the filter first when the main engine is running normally. Because the oil temperature is high and the viscosity is small, the filtering effect can be better. The second way is to put the filter on the water-cooled burst tester. What are the common faults? After the heater. Advantages: when the cold car starts, the radiator can be filled with hot water (when the cooling system is filled with hot water). As the oil temperature rises, the oil is easy to pass through the filter

based on the above analysis, the full flow oil filter should be connected behind the radiator. The oil temperature in the filter can be controlled, and the filtering effect is relatively stable. The shunt filter should be installed before the radiator. Even if there is no oil passing through the filter during starting, it is not a big problem. And the motivation of the cloud is positive

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