molecular pumpIt is a vacuum pump that uses a high-speed rotating rotor to transfer momentum to gas molecules, allowing them to obtain directional velocity and be compressed, driven towards the exhaust port, and then pumped away by the front stage. This type of pump can be specifically divided into:
1.The gas molecules of the traction molecular pump collide with the high-speed rotor to obtain momentum, and are driven to the outlet of the pump.
2.Turbomolecular pumps rely on the cooperation between high-speed rotating moving blades and stationary fixed blades to achieve pumping. This type of pump typically operates in a molecular flow state.
3.A composite molecular pump is a type of molecular vacuum pump that is composed of two types of molecular pumps, turbine type and traction type, connected in series.
Composite molecular pumpIt is a series combination of turbo molecular pump and traction molecular pump, integrating the advantages of both pumps. The pump has a high pumping speed and compression ratio over a wide pressure range (10-6~1Pa), greatly increasing the outlet pressure of the pump. There are many forms of composite molecular pumps, which can be divided into two main types according to their structures: one is the series combination of turbine blades and disc traction pumps; Another type is the series combination of turbine blades and cylindrical traction pumps; as shown below
1. Turbine stageMainly used to increase the pumping speed of the pump, generally using blade shapes that are conducive to increasing pumping speed, with stages within 10. The traction stage is mainly used to increase the compression ratio of the pump and increase the outlet pressure of the pump.
2. Disc type traction stageIt is a process of creating several grooves on a flat disc according to a certain pattern, and then connecting several discs in series to form the grooves. The grooves include Archimedean spiral, logarithmic spiral, arc line, etc. During gas extraction, a high-speed rotating disk is used to "drag" gas molecules, causing them to flow back and forth along the groove in a directional manner from inside to outside and from outside to inside, thus achieving the purpose of extraction.