to the specific analysis of the working condition of crankshaft bearing
of internal combustion engine, the main reasons for the damage of
bearing friction power are as follows:
With the decrease of the surface roughness of journal and bearing, the
friction power loss of main bearing decreases obviously. When the
surface roughness reaches a certain level, the friction power loss
basically remains unchanged;Therefore,
in order to reduce the friction power loss, the surface roughness level
of journal and bearing should be appropriately improved.
As the working temperature of lubricating oil increases, the friction
power loss of the main bearing decreases, and the decrease range varies
greatly with the temperature. However, if the temperature is too high,
the viscosity of lubricating oil decreases, and the bearing capacity
on the premise of ensuring the bearing capacity, the appropriate
increase of temperature is beneficial to reduce the friction power loss.
Under the same working condition, the speed of internal combustion
engine increases, and the friction power loss of main bearing increases
significantly;Therefore, low speed bearings should be selected within a reasonable speed range to reduce the friction power loss.
Different clearance of the main bearing has different effects on the
power loss of the main bearing. With the increase of clearance, the
power loss tends to decrease.Therefore, the situation of too small clearance should be avoided in engineering practice.
The change of oil supply advance Angle has an impact on the friction
power loss of the main bearing. Within a certain range, the power loss
changes relatively close to that of the main bearing; if beyond a
certain range, the power loss changes greatly.
In the design stage of main bearing of internal combustion engine,
bearing surface roughness and bearing clearance should be considered as
the main factors affecting friction power loss of main bearing of
internal combustion engine under the premise of considering friction
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 conducive to reducing the
friction power loss of the bearing.