When the engine is running, the oil pump extracts the oil from the oil pan, and under pressure, the oil with impurities enters the filter through the inlet on the oil filter base plate. The engine oil passes through the check valve and reaches the outside of the filter paper for filtration. Under the action of oil pressure, the oil passes through the filter paper and enters the central tube, while impurities in the oil are intercepted by the filter paper and remain on it. The purified engine oil flows out from the central pipe and is sent to various parts of the engine that require lubrication. This process can be understood as a "purification journey", and filter paper is the core "filtration responsibility".


The working principle of a machine filter is essentially to use pressure difference to drive filtration, while integrating intelligent safety protection mechanisms.

Filtering principle: The oil pump pumps oil into the filter, and the oil flows from the outside to the inside of the filter paper under the pressure difference. The pore size of filter paper is smaller than the size of impurities in engine oil, so impurities are intercepted on the surface or deep layers of the filter paper, while engine oil molecules pass through the filter paper and are purified.

Intelligent bypass mechanism: This is the essence of filter design. The opening pressure of the bypass valve is a precisely calculated equilibrium point.

Low pressure (set value too low): This can cause the bypass valve to be in an open or semi open state under normal circumstances, allowing a large amount of oil to enter the engine directly without filtering, resulting in the filter being ineffective and increasing engine wear.

Excessive pressure (set value too high): When the filter element is clogged, the oil pressure cannot reach the opening value, and the bypass valve cannot be opened in time, which may cause severe wear and even erosion of the engine due to lack of oil, losing the protective effect of the "safety valve".

Accurate setting: The opening pressure of the bypass valve of the high-quality oil filter will be precisely matched with the normal working pressure of the engine main oil passage and the pressure regulating valve of the oil pump, ensuring that emergency lubrication can be provided in extreme situations while minimizing the chance of unfiltered oil entering the engine.

Cold start protection of check valve: Cold start is the most severe stage of engine wear. The check valve ensures that there is always oil in the filter, shortening the time difference for oil to be pumped from the oil pan to key engine components, allowing the oil to establish an effective lubricating oil film in a very short time after starting, significantly reducing dry wear during cold start.