EP 0769104 B1 19990901 - HELICAL GEAR PUMP OR MOTOR
Title (en)
HELICAL GEAR PUMP OR MOTOR
Title (de)
SCHRÄGVERZAHNTE ZAHNRADPUMPE ODER-MOTOR
Title (fr)
POMPE OU MOTEUR A ENGRENAGES HELICOIDAUX
Publication
Application
Priority
- GB 9501610 W 19950707
- GB 9413676 A 19940707
- GB 9506824 A 19950401
Abstract (en)
[origin: WO9601950A1] Hydraulic apparatus, for example a gear pump or motor, for low noise generation employs helical gears (8 and 10) retained within a casing. The contact ratio and the helical advance of the gear teeth (which may be approximately 2 and 1, respectively) are such as to substantially prevent back-flow of hydraulic fluid from the outlet side to the inlet side. In the case of a gear pump, a pressure relief recess (70 or 74) and a fluid feed recess (72 or 76) can communicate with the spaces between the teeth in the meshing zone at each end of the gears, the recesses being so shaped and positioned as to avoid communication with each other by way of said spaces, and the disposition of said recesses at one end of the gears relative to those at the other end thereof being staggered by an amount corresponding to the helical advance. Each pressure relief recess is a slot having a basic end surface (78 or 82) beyond which there extends a subsidiary slot or "nose" (80 or 84), and each fluid feed recess is a slot interconnecting the bearings for the shafts carrying the gears. In the case of a reversible gear motor, respective pressure relief recesses communicate with both ports of the motor at each end of the gears.
IPC 1-7
IPC 8 full level
CPC (source: EP KR)
F04C 2/02 (2013.01 - KR); F04C 2/084 (2013.01 - EP); F04C 2/16 (2013.01 - EP)
Designated contracting state (EPC)
AT BE CH DE DK ES FR GR IE IT LI LU MC NL PT SE
DOCDB simple family (publication)
WO 9601950 A1 19960125; AT E184080 T1 19990915; AU 2892895 A 19960209; DE 69511870 D1 19991007; DE 69511870 T2 20000504; EP 0769104 A1 19970423; EP 0769104 B1 19990901; GB 2304155 A 19970312; GB 2304155 B 19980819; GB 9700560 D0 19970305; JP 3972072 B2 20070905; JP H10502715 A 19980310; KR 970704968 A 19970906
DOCDB simple family (application)
GB 9501610 W 19950707; AT 95943151 T 19950707; AU 2892895 A 19950707; DE 69511870 T 19950707; EP 95943151 A 19950707; GB 9700560 A 19950707; JP 50418896 A 19950707; KR 19970700047 A 19970107