US 12,188,477 B2
Vacuum pump and rotating cylinder provided in vacuum pump
Tooru Miwata, Chiba (JP); Yoshiyuki Sakaguchi, Chiba (JP); Yoshiyuki Takai, Chiba (JP); and Yasuhiro Shibata, Chiba (JP)
Assigned to Edwards Japan Limited, Chiba (JP)
Appl. No. 18/044,815
Filed by Edwards Japan Limited, Chiba (JP)
PCT Filed Oct. 1, 2021, PCT No. PCT/JP2021/036488
§ 371(c)(1), (2) Date Mar. 10, 2023,
PCT Pub. No. WO2022/075228, PCT Pub. Date Apr. 14, 2022.
Claims priority of application No. 2020-171094 (JP), filed on Oct. 9, 2020.
Prior Publication US 2024/0026888 A1, Jan. 25, 2024
Int. Cl. F04D 19/04 (2006.01); F04D 29/32 (2006.01)
CPC F04D 19/042 (2013.01) [F04D 29/321 (2013.01); F05D 2250/292 (2013.01)] 4 Claims
OG exemplary drawing
 
1. A vacuum pump comprising:
a casing having an inlet port and an outlet port;
a threaded spacer that is fixed to the casing and includes a thread groove;
a rotating shaft that is enclosed and rotationally supported by the casing; and
a rotating cylinder disposed on the rotating shaft, the rotating cylinder including an opposed portion facing the threaded spacer across a clearance and an extension portion extending to a further downstream side than the threaded spacer, wherein
the extension portion includes: a gradually decreasing diameter structure having an outer diameter that decreases from the inlet port toward the outlet port; and a reduced diameter portion having an outer diameter that is smaller than an outer diameter of the opposed portion, the reduced diameter portion being disposed on a side of the outlet port with respect to the gradually decreasing diameter structure.