The choice of oil viscosity has close relationship with bearing specific pressure, hollow axis speed and oil temperature.
The pressure of crusher bearings is greater, the need for oil viscosity is larger. It can increase the carrying capacity of the oil film; higher the speed of the shaft line, the film is more easy to form, it may be appropriate to reduce the viscosity. The higher of oil temperature, the lubrication oil become dilute, the carrying capacity of the oil film is decreased, so it should use the higher viscosity of oil. If it is opposite, it is the same like this.
For mill main bearing, the bearing pressure ratio is within 1.6 ~ 1.9N/mm2; the line speed is within the range of 1.2 ~ 3.6m / s, once the mill has been put into operation, the specific pressure ratio and the line speed has been unable to be changed, it is a constant, and therefore the oil temperature can only affect the viscosity. Here it must be pointed out that the temperature of the oil of the mill main bearing means embedded in the bush with the end face of the temperature of the thermal resistance, because it is very close to the temperature of the oil in the bearing friction pair.