Vacuum oil, also known as molecular pump oil, which is a refined mineral oil, usually used in a molecular pump or a vacuum pump, and the vacuum oil is greatly different from the general oil. The appropriate use performance and viscosity grade of the vacuum oil should be selected according to the equipment manufacturer’s oil requirements.
In the process of using the heat transfer oil pump, the vacuum oil is directly enters the cavity of the pump body, when the vacuum pump is operating, as the gas pressure gradually decreases and the pump temperature gradually increases, the molecular components with high saturated vapor pressure in the oil product can evaporation to the vacuum space, which affects the vacuum pump reaches the ultimate pressure, will return to the vacuum system diffusion, pollution of the vacuum system, and directly affect the ultimate vacuum. The working principle of the vacuum gear pump belongs to the positive displacement pump. When the heat conduction oil pump works, it depends on the mutual engagement between the main and driven gears, causing the volume change to transport the melt.
The working volume is composed of the pump body, the tooth space of the gear and the bearing housing with the function of the side plate. When the gear rotates, the melt enters the alveolar cavity of the two gear of the suction chamber. With the rotation, the melt is brought into the discharge cavity from both sides, and the gear is meshed again, so that the melt in the alveolus is extruded and discharged, and the pressure is sent to the outlet pipe. The bearings cannot use the usual lubricating grease, to avoid the contamination of the melt, the general use of self-lubricating melt.
The working chamber of the heat transfer oil pump is continuously increasing or shrinks. When the volume of the work chamber becomes smaller, it connects with the inlet pipe of the vacuum pump, so the gas enters the gradually increased working space. When the volume of the work chamber expands, it is separated from the inlet pipe to make the volume valve open. The volume of the pump is continuously expanded and compressed, and the suction and exhaust processes are completed, so that the gas in the chamber is gradually discharged to the required degree of vacuum. The operation of the vacuum pump, with the rotation of the pump chamber rotor, the rotor vane or the eccentric wheel slide ring two longitudinal groove, cling to the inner wall of the stator sliding. Rotor, vane and inner wall of stator heat-transfer pump must rely on lubricating oil to avoid friction material, isolates the atmosphere with oil, and removes the heat generated by friction.
Therefore, the vacuum oil plays the role of lubrication, sealing, and cooling in the pump body.