Turbo-molecular type vacuum pump - has spaces inside and outside rotor bell sealed from each other to increase vacuum obtained

摘要

The pump has a bell shaped rotor (3) inside a stator (2). Radial blades (9) on the outside of the rotor bell interleave with radial blades (11) on the inside of the stator. The shaft (7) of the rotor is held in bearings (5,6) in a stator bell within the space (4) inside the rotor bell. The bottom (21) of the rotor bell is taken close to the end wall of the stator and a labyrinth seal (28) is formed to separate the bearing space inside the rotor bell from the pumping space (12) outside the bell. There is a gas outlet connection (23,24) in each of these spaces.