To provide a turbo vacuum pump using a circumferential flow blade element, in which a large amount of flow rate exhaust can be implemented in the vacuum range from several Pa to tens of thousands of Pa.
The turbo vacuum pump is provided with the circumferential flow blade element 36 having a plurality of impeller blades 37 extending radially, a fixed blade 38 having a circumferential groove 4 extending circumferentially, and a casing 10 storing the circumferential flow blade element 36 and the fixed blade 38. The fixed blade 38 has an opening 42 to introduce gas. A suction passage 41 to transfer and introduce the gas introduced from the opening 42 radially outward into the circumferential groove 4 is formed at least at one side of the circumferential flow blade 36 and the fixed blade 38.
Shintaro Hotta
Ryoji Kosugi
Tomohiro Mori