The mechanical pump is a vital part of the vacuum coating machine, but many people do not know much about this part. The following is a detailed introduction to the vacuum series, hoping to help you:

Mechanical pump: also known as the backing pump, the mechanical pump is the most widely used low vacuum pump. It uses oil to maintain the sealing effect and relies on mechanical methods to continuously change the volume of the suction cavity in the pump to make the pumped container. The volume of the gas inside expands continuously to obtain a vacuum.

       1. Classification of mechanical pumps: There are many kinds of mechanical pumps, commonly used are slide valve type (this is mainly used in large equipment), piston reciprocating type, fixed plate type and rotary vane type (this is currently the most widely used, this article mainly introduces) Four types.

       2. The mechanical pump starts to work from the atmosphere, and its main parameters are the ultimate vacuum and the pumping rate, which are the 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 two-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 number of revolutions. It can be calculated by the following formula: Sth=2nVs=2nfsL fs represents the cross-sectional area of the cavity at the end of suction, and L represents the empty space. The length of the cavity, the coefficient means that the rotor has two exhausting processes every one rotation, Vs means that when the rotor is in a horizontal position, the suction ends, the volume in the cavity is the largest at this time, and the 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 speed of the motor is very slow, the exhaust effect of the mechanical pump will also deteriorate, so it is necessary to maintain it frequently. Check, the sealing effect of the mechanical pump oil also needs to be checked frequently. If the oil is too small, the sealing effect will not be achieved, and the pump will leak air. The oil level should be 0.5 cm below the line.
       3. The mechanical pump of the vacuum coating machine is often used to pump out dry air, but it cannot pump out the gas with high oxygen content, explosive and corrosive gas. The mechanical pump is generally used to pump out the permanent gas, but the Moisture doesn't have a good effect, so it can't pump it out. The main parts of the rotary vane pump are the stator, rotor, shrapnel, etc. The rotor is inside the stator but has a different mandrel from the stator, like two inscribed circles. It is ensured that the shrapnel is tightly attached to the inner wall of the stator.