EP 1557564 A1 20050727 - Reversible pump for driving hydraulic cylinders
Title (en)
Reversible pump for driving hydraulic cylinders
Title (de)
Umkehrbare Pumpeneinheit zum Antrieb hydraulischer Zylinder
Title (fr)
Unité de pompage réversible pour l'entrainement de cylindres hydrauliques
Publication
Application
Priority
EP 04250372 A 20040123
Abstract (en)
A pump and motor assembly (10) for supplying fluid to a double acting hydraulic cylinder the ends of which are connected to two exit ports (1, 2) provided on the pump housing (11). A single acting piston (5) reciprocates and rotates simultaneously on the piston axis with the reciprocating motion imparted by a single row ball bearing (13) mounted on the piston (5) and inclined at an angle to the piston axis and having a single point on the outer race of the single row ball bearing (13) restrained. The pump includes two one way check valves (25, 26 and 27, 28) in passages between a reservoir (24) and the exit ports (1,2) that allow fluid to be drawn into the pumping chamber (7) when the attached cylinder is expanding. A bleed valve, constructed using two balls (30, 31) allows fluid displaced by the rod of a double acting cylinder to be returned through a third passage (35) to the reservoir (24) when the attached cylinder is retracting. <IMAGE>
IPC 1-7
IPC 8 full level
F04B 7/06 (2006.01)
CPC (source: EP)
F04B 7/06 (2013.01)
Citation (search report)
- [XD] US 4902208 A 19900220 - WOOD R A RAY [CA]
- [XD] US 5015157 A 19910514 - PINKERTON DENNIS [US], et al
- [XD] US 3083895 A 19630402 - WELLES JR DONALD P
Designated contracting state (EPC)
FR IT
DOCDB simple family (publication)
DOCDB simple family (application)
EP 04250372 A 20040123