As an important index parameter of oil, oil viscosity will directly determine the operation of the system. When the viscosity of the oil is too high, vertical roller mill will increase the flow loss, reduce the transmission efficiency, and cause the oil temperature to be too high. 

In addition, when the viscosity is too low, it will increase the leakage, reduce the volumetric efficiency of the system, and cause the oil temperature to rise. In addition, the decrease of viscosity will lead to the decrease of lubrication performance, the increase of friction and the obvious rise of oil temperature.

Working oil is mainly dissipated by radiator. Vertical mill's radiator is air-cooled structure, so when the radiator is blocked, the heat dissipation effect will be reduced.