At different temperatures, the lubricity and cooling performance of vacuum pump oil will change. Lubricity is closely related to the viscosity of the oil. The higher the viscosity, the better the lubricity of the oil. However, too high viscosity may increase friction resistance and temperature rise, thereby increasing power loss. When the viscosity is too low, the sealing performance of the pump will deteriorate, which may cause gas leakage and affect the vacuum degree. Therefore, choosing a vacuum pump oil with the right viscosity is crucial to achieve good liquid lubrication and reduce the generation of friction heat.

At different temperatures, the lubricity and cooling performance of vacuum pump oil will change. Lubricity is closely related to the viscosity of the oil. The higher the viscosity, the better the lubricity of the oil. However, too high viscosity may increase friction resistance and temperature rise, thereby increasing power loss. When the viscosity is too low, the sealing performance of the pump will deteriorate, which may cause gas leakage and affect the vacuum degree. Therefore, choosing a vacuum pump oil with the right viscosity is crucial to achieve good liquid lubrication and reduce the generation of friction heat.

The saturated vapor pressure of vacuum pump oil is also one of the key indicators that affect its performance. In a closed container at a constant temperature, the pressure when the vapor and liquid phases reach dynamic equilibrium is called the saturated vapor pressure. The saturated vapor pressure of the oil should be as low as possible. At the highest operating temperature of the pump, the saturated vapor pressure should still be kept low enough and lower than the limit pressure specified by the vacuum pump. At 60°C, the saturated vapor pressure must be at least 6.5×10^-8 kPa, and the saturated vapor pressure will drop by about an order of magnitude with every 20°C increase in temperature.

In summary, the changes in lubricity and cooling performance of vacuum pump oil at different temperatures need to be optimized by rationally selecting the viscosity of the oil and considering its saturated vapor pressure and other characteristics to ensure that the vacuum pump can maintain good operating conditions under various working conditions.