Vacuum Pump Structure
What are the structures of vacuum pumps?
(1) General structure of pump
The layout structure of the pump body of the vacuum pump determines the overall structure of the pump.
Vertical structure of the intake and exhaust port level settings, assembly and connection pipelines are more convenient. But the center of gravity of the pump is high and its stability is poor at high speed, so this type of pump is mostly used in small pumps.
Horizontal pump intake is in the upper, exhaust is in the lower. Sometimes in order to facilitate the installation and connection of the vacuum system pipeline, the exhaust outlet can be connected from the horizontal direction, that is, the direction of intake and exhaust is mutually perpendicular. At this time, the exhaust outlet can be opened in both left and right directions. In addition to one end of the exhaust pipe, the other end is blocked or connected with a bypass valve. The pump has low center of gravity and good stability at high speed. Generally large and medium-sized pumps use this structure.
The two rotor shafts of the pump are installed vertically with the horizontal plane. The assembly clearance of the structure is easy to control, the assembly of the rotor is convenient, and the area of the pump is small. However, the centroid of the pump is high, the gear disassembly and assembly is inconvenient, and the lubrication mechanism is relatively complex.
(2) Driving mode of pump
The two rotors of the vacuum pump operate relatively synchronously through a pair of high precision gears. The drive shaft is connected with the motor through a coupling. There are mainly two kinds of transmission structure arrangement: one is that the motor and the gear are placed on the same side of the rotor. The driven rotor is driven directly by the end gear of the motor, so that the torsional deformation of the active rotor shaft is small, and the clearance between the two rotors will not change because of the torsional deformation of the active shaft, so that the clearance between the rotors is uniform in the course of operation. The biggest disadvantage of this transmission mode is: a. There are three bearings on the drive shaft, which increases the difficulty of processing and assembling the pump, and the disassembly and adjustment of the gears are inconvenient; B. The overall structure is not symmetrical, and the center of gravity of the pump is biased to the side of the motor and gear box.