The crankshaft bearing of the internal combustion engine is one of the main friction pairs in the work of the internal combustion engine, and its working process will form a dynamic load radial lubricating oil film. The working state of the crankshaft main bearing directly affects the reliability, durability and economy of the internal combustion engine, and also affects the work of the internal combustion engine. life. The tribological behavior and dynamic behavior of the crankshaft-bearing system occur simultaneously, and there is a strong fusion effect that cannot be ignored; therefore, the problem of frictional power loss is unavoidable. So why is the friction power of the crankshaft bearing of the internal combustion engine damaged?

According to the specific analysis of the working conditions of the crankshaft bearing of the internal combustion engine, it is known that the main reasons for the damage of the bearing friction power are as follows:

1. With the decrease of the surface roughness of the journal and bearing, the frictional power loss of the main bearing is significantly reduced. After reaching a certain roughness level, the frictional power loss remains basically unchanged; therefore, in order to reduce the frictional power loss, the shaft should be properly increased. The level of surface roughness of neck and bearing.

2. When the working temperature of the lubricating oil increases, the frictional power loss of the main bearing decreases, and the magnitude of the decrease varies greatly with the temperature. However, if the temperature is too high, the viscosity of the lubricating oil decreases, and the bearing capacity of the bearing will decrease; therefore, in order to ensure the bearing capacity Under the premise of force, an appropriate increase in temperature is beneficial to reduce frictional power loss.

3. Under the same working conditions, when the speed of the internal combustion engine increases, the frictional power loss of the main bearing increases significantly; therefore, within a reasonable speed range, a bearing with a low speed should be selected to reduce the frictional power loss.

4. Different main bearing clearances have different effects on the power loss of the main bearing. As the clearance increases, the power loss tends to decrease. If the bearing clearance is too small, the frictional power loss increases rapidly; therefore, excessive clearance should be avoided in engineering practice. small case.

5. The change of the oil supply advance angle has an impact on the friction power loss of the main bearing. Within a certain range, the power loss change is relatively close. If it exceeds a certain range, the power loss changes greatly.

6. In the design stage of the internal combustion engine main bearing, under the premise of considering the frictional power loss, the bearing surface roughness and bearing clearance should be considered as the main factors affecting the frictional power loss of the internal combustion engine main bearing; secondly, within a given speed and temperature range , Appropriately reducing the working speed of the main bearing and appropriately increasing the working temperature of the lubricating oil are beneficial to reduce the frictional power loss of the bearing.