US 12,110,896 B2
Axial flow vacuum pump with curved rotor and stator blades
Nigel Paul Schofield, Burgess Hill (GB); and Stephen Dowdeswell, Burgess Hill (GB)
Assigned to Edwards Limited, Burgess Hill (GB)
Appl. No. 17/904,143
Filed by Edwards Limited, Burgess Hill (GB)
PCT Filed Feb. 10, 2021, PCT No. PCT/GB2021/050301
§ 371(c)(1), (2) Date Aug. 12, 2022,
PCT Pub. No. WO2021/161010, PCT Pub. Date Aug. 19, 2021.
Claims priority of application No. 2001992 (GB), filed on Feb. 13, 2020.
Prior Publication US 2023/0109154 A1, Apr. 6, 2023
Int. Cl. F04D 19/04 (2006.01); F04D 29/32 (2006.01); F04D 29/38 (2006.01); F04D 29/54 (2006.01)
CPC F04D 19/048 (2013.01) [F04D 29/32 (2013.01); F04D 29/38 (2013.01); F04D 29/542 (2013.01)] 13 Claims
OG exemplary drawing
 
1. An axial flow vacuum pump for evacuating a chamber in a semiconductor manufacturing process, the axial flow vacuum pump comprising:
a rotor having a plurality of rotor blades; and
a stator having a plurality of stator blades, wherein the rotor blades and stator blades have a curved aerofoil cross-sectional shape comprising a curved leading edge, a pointed trailing edge, a concaved pressure surface extending from the leading edge to the trailing edge and a curved suction surface extending from the leading edge to the trailing edge, wherein the concaved pressure surface of each rotor faces in a direction of rotation of the rotor;
wherein an inlet stage of the pump comprises blades having a first radial length and an adjacent downstream stage of the pump comprises blades having a second radial length, wherein the ratio of first radial length to second radial length is 2:1 or greater.