When the workpiece is coated in the pvd coating machine, it needs to be carried out in a vacuum state. Therefore, the accessories that the pvd coating machine needs to be vacuumed are definitely indispensable. Below, the editor of Huicheng Vacuum will introduce in detail how to use the accessories of the vacuum coating machine's exhaust system. , hope it can help everyone:

Working principle of mechanical pump:
Its two shrapnels alternately play two roles. On the one hand, it sucks in gas from the air inlet, and on the other hand, it compresses the sucked gas and discharges the gas out of the pump. For each revolution of the rotor, the pump completes two suctions and two discharges. When the pump continuously rotates clockwise, the rotary vane pump continuously inhales gas through the air inlet and continuously discharges it from the exhaust port to achieve the purpose of pumping air from the container. In order to improve the ultimate vacuum degree of the pump, the stator of the pump is immersed in oil. In this way, enough oil is always maintained in the gaps and harmful spaces everywhere to fill the gaps. Therefore, the oil plays a lubricating role on the one hand and also plays a role in lubrication on the other hand. On the one hand, it also plays the role of sealing and blocking gaps and harmful spaces, preventing gas molecules from flowing back through various channels to spaces with low pressure.
The mechanical pump starts working from the atmosphere. Its main parameters include ultimate vacuum and pumping rate. This is an important basis for the design and selection of the mechanical pump. The single-stage pump can pump the container from the atmosphere to the ultimate vacuum of 1.0*10-1PA, and the double-stage mechanical pump can pump the container from the atmosphere to 6.7*10-2PA, or even higher.
The pumping rate refers to the volume of gas that can be discharged per unit time when the rotary vane pump operates at the rated speed. It can be calculated using the following formula:
Sth=2nVs=2nfsL
fs represents the cross-sectional area of the cavity at the end of suction, L represents the length of the cavity, the coefficient indicates that there are two exhaust processes per rotation of the rotor, Vs represents that when the rotor is in the horizontal position, the suction ends, and the volume in the cavity is the largest at this time , the rotation speed is n.
The exhaust effect of the mechanical pump is also related to the speed of the motor and the tightness of the belt. When the belt of the motor is relatively loose and the motor speed is very slow, the exhaust effect of the mechanical pump will also become worse, so regular maintenance is required. Inspection, the sealing effect of mechanical pump oil also needs to be checked frequently. If there is too little oil, the sealing effect cannot be achieved, and air will leak in the pump. Too much oil will block the suction hole, making it impossible to inhale and exhaust. Generally, in The oil level is 0.5 cm below the line.
When using the mechanical pump of the pvd coating machine, you must pay attention to the following issues:
1. The mechanical pump should be installed in a clean and dry place.
2. The pump itself must be kept clean and dry. The oil in the pump has sealing and lubricating effects, so it must be added in the specified amount.
3. Pump oil must be replaced regularly. When replacing, the previous waste oil must be discharged first. The cycle should be at least three months to six months.
4. Connect the wires according to the instructions.
5. Before stopping the mechanical pump, close the air inlet valve first, then cut off the power and open the air valve, and let the atmosphere into the pump through the air inlet.
6. During the operation of the pump, the oil temperature cannot exceed 75 degrees Celsius, otherwise the sealing will be loose due to the low viscosity of the oil.
7. Check the belt tightness of the mechanical pump, the speed of the motor, the speed of the Roots pump motor, and the sealing effect of the sealing ring from time to time.