The crankshaft is the main rotating mechanism of the engine, which is responsible for transforming the up and down reciprocating motion of the piston into its own circular motion, and generally speaking, the engine speed is the rotational speed of the crankshaft.
The crankshaft will wear due to the uncleanness of the oil and the uneven bearing force of the journal. The joint between the big head and the journal of the connecting rod will be worn. If there are large hard particles in the oil, there is a danger of scratching the surface of the journal. If the wear is severe, it is likely to affect the stroke length of the piston up and down, reduce the combustion efficiency, and naturally also the smaller power output. In addition, the crankshaft may also cause burns on the surface of the journal due to insufficient lubrication or excessive oil, which may affect the reciprocating motion of the piston in severe cases. Therefore, it is necessary to use a lubricant of suitable viscosity and to ensure the cleanliness of the oil.