Today’s car engines use a full-flow filtration system. What is full-flow?
That is, all the oil passes through the oil filter, leaving the impurities and then supplying them, that is, the engine is filtered from time to time, and each drop is filtered.
But I tell you that this is only a theoretical state, why? Look at the picture below:
There is a pressure difference in the filtration system: the pressure of the oil inlet is high, and the pressure of the oil is low, which is inevitable. You wear a mask, which is also a filtration system, you can find the air resistance when breathing.
The oil filter of the engine has a pressure difference when it is working, the pressure from the oil pump is high, and the pressure output to the main lubricating oil of the engine is slightly lower. With a filter paper with a large filter capacity or a new filter paper, this pressure difference is small, so full-flow filtration is guaranteed. If the pressure difference is large, the oil is blocked at the oil inlet end, the flow at the oil outlet is small, and the pressure in the main oil passage is also small, which is very dangerous.
In order to ensure the pressure supply of the main oil passage, the bottom of the oil filter is designed with a bypass valve. When the pressure difference is high to a certain extent, the bypass valve is opened, so that the oil directly enters the main oil passage cycle without filtering through the filter paper. At this time, it is not full-flow filtering, it is partial filtering. If the oil is deeply oxidized, the sludge and gel coat the surface of the filter paper, and the bypass valve circulation mode is completely unfiltered. Therefore, everyone should change the oil and oil filter regularly! At the same time, choose a good oil filter, do not figure cheap, buy a filter with a low filtration grade.
Several reasons and conditions for opening the bypass valve:
1, filter paper impurities and dirt too much. The flow rate can be filtered at a small speed, and the large speed flow bypass valve is opened for partial filtration.
2. After the filter paper passing capacity is reduced, the oil flow rate increases sharply – for example, the sudden speed of the speed refers to 4000-5000 rpm, and the bypass valve opens for partial filtering.
3, long-term non-changing oil, oil filter paper dredging is covered or blocked – so that any speed bypass valve is open, idle speed may also open.
Let’s take a look at the structure and parts drawing of the oil filter, so that you can understand more clearly: From the above, you can see the importance of the oil filter, so how important it is to choose a good oil filter. Poor filter paper filter has low filtration precision and can not filter. If the oil filter is blocked for a long time, the bypass valve will open and the engine will be directly supplied without filtration.
Post time: May-10-2019