The arrangement structure of the pump body of the vacuum pump determines the overall structure of the pump. The inlet and exhaust ports of the vertical structure are arranged horizontally, making it easier to assemble and connect the pipeline. However, the pump has a high center of gravity and poor stability during high-speed operation, so this type is mostly used for small pumps. The intake port of the horizontal pump is on the top, and the exhaust port is on the bottom. Sometimes in order to facilitate the installation and connection of vacuum system pipes, the exhaust port can be connected from the horizontal direction, that is, the inlet and exhaust directions are perpendicular to each other. At this time, the exhaust port can be opened from left or right. Except for one end of the exhaust pipe, the other end is blocked or connected to a bypass valve. The pump structure has a low center of gravity and good stability during high-speed operation. Generally, large and medium pumps adopt this structure. The two rotor shafts of the pump are installed perpendicular to the horizontal plane. The assembly clearance of this structure is easy to control, the rotor is easy to assemble, and the pump has a small footprint. However, the pump has a high center of gravity and inconvenient disassembly and assembly of gears. The lubrication mechanism is also relatively complicated.
The two rotors of the vacuum pump realize their relative synchronous operation through a pair of high-precision gears. The driving shaft is connected with the motor through a coupling. There are two main types of transmission structure layout: One is that the motor and gear are placed on the same side of the rotor. The driven rotor is directly driven by the gear at the motor end, so that the torsional deformation of the driving rotor shaft is small, and the gap between the two rotors will not change due to the large torsional deformation of the driving shaft, so the gap between the rotors is running The process is uniform.