EP 0866918 B1 19991229 - TWIN FEED SCREW
Title (en)
TWIN FEED SCREW
Title (de)
ZWILLINGS-FÖRDERSCHRAUBEN
Title (fr)
VIS TRANSPORTEUSES JUMELEES
Publication
Application
Priority
- CH 9600251 W 19960708
- CH 348895 A 19951211
- CH 362895 A 19951221
Abstract (en)
[origin: WO9721926A1] In known embodiments, media are fed in a contact-free manner in propeller pumps by single-thread twin feed screws which are guided via pilot gears, the twin feed screws having the same transverse profile with a core circle, tip circle, an involute flank and a hollow flank, enabling the pump chamber to be divided into axially staggered cells and thus obtain high pressure differences in one stage. In addition to dynamics, efficiency and production, the control of the medium is also determined by the contour of the end profile, the variation of which improves all the dependent variables. According to the invention, the involute is replaced by a curve which does not rise constantly and has a central saddle region and a smooth connection to the core circle. The variations in the end face achieved thereby improve the dynamics and volumetric efficiency and extend the possibilities for controlling medium at the end face. The detailed adaptation to the new curve together with the smooth connection at the base point enable the core and flanks to be produced jointly by a single tool. Feed screws with profiles of this type are suitable for flow rates of between 100 and 100 m<3>/h and ultimate pressure of < 0.05 mbar at speeds of rotation of approximately 3000 min<-1> and approximately 50 % efficiency.
IPC 1-7
IPC 8 full level
F04C 18/16 (2006.01); F04C 18/08 (2006.01)
CPC (source: EP KR US)
F04C 18/08 (2013.01 - KR); F04C 18/084 (2013.01 - EP US); F04C 18/16 (2013.01 - EP US)
Designated contracting state (EPC)
AT BE CH DE DK ES FI FR GB IE IT LI LU NL PT SE
DOCDB simple family (publication)
WO 9721926 A1 19970619; AT E188277 T1 20000115; AU 6186296 A 19970703; AU 720108 B2 20000525; CA 2240169 A1 19970619; CA 2240169 C 20071204; CN 1089409 C 20020821; CN 1207795 A 19990210; CZ 177198 A3 20000315; CZ 289348 B6 20020116; DE 59604068 D1 20000203; EP 0866918 A1 19980930; EP 0866918 B1 19991229; ES 2140867 T3 20000301; JP 2000501810 A 20000215; JP 4057059 B2 20080305; KR 100384926 B1 20030821; KR 19990072057 A 19990927; NO 982675 D0 19980610; NO 982675 L 19980807; PT 866918 E 20000428; SK 281393 B6 20010312; SK 78198 A3 19990211; US 6129535 A 20001010
DOCDB simple family (application)
CH 9600251 W 19960708; AT 96920677 T 19960708; AU 6186296 A 19960708; CA 2240169 A 19960708; CN 96199627 A 19960708; CZ 177198 A 19960708; DE 59604068 T 19960708; EP 96920677 A 19960708; ES 96920677 T 19960708; JP 52157797 A 19960708; KR 19980704358 A 19980611; NO 982675 A 19980610; PT 96920677 T 19960708; SK 78198 A 19960708; US 7796598 A 19980824