EP 3499041 B1 20200701 - SCREW VACUUM PUMP
Title (en)
SCREW VACUUM PUMP
Title (de)
SCHRAUBENVAKUUMPUMPE
Title (fr)
POMPE À VIDE À VIS
Publication
Application
Priority
EP 17207558 A 20171215
Abstract (en)
[origin: JP2019143620A] To reduce a requisite manufacturing accuracy against at least a partial area of a shape realizing a pump effect.SOLUTION: This invention relates to a screw type vacuum pump characterized in that screw type rotors (28, 30) are acted with a housing (16) to form a transportation volume filled with process gas repeatedly, the volume is transported toward an outlet and at that time each of the rotors has at least two portions (62, 64) that are adjacent along a screw shaft and at that time, each of the screw type rotors (28, 30) has at least basically a specified inclination in a first portion (62) placed near an inlet and then has a smaller inclination than that in the first portion (62) in the second portion (64) and at that time the first portion (62) in regard to a screw shaft (63) is longer than the transportation volume closed in the first portion (62).SELECTED DRAWING: Figure 4
IPC 8 full level
F04C 25/02 (2006.01); F04C 18/08 (2006.01); F04C 18/16 (2006.01)
CPC (source: EP)
F04C 18/084 (2013.01); F04C 18/16 (2013.01); F04C 25/02 (2013.01)
Designated contracting state (EPC)
AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR
DOCDB simple family (publication)
EP 3499041 A1 20190619; EP 3499041 B1 20200701; JP 2019143620 A 20190829; JP 2021102960 A 20210715; JP 7339973 B2 20230906
DOCDB simple family (application)
EP 17207558 A 20171215; JP 2018232382 A 20181212; JP 2021011798 A 20210128