Title:
HYDRAULIC PUMP
Document Type and Number:
Japanese Patent JPS572481
Kind Code:
A
Abstract:
The pump with fixed skew plate (5) comprises pistons (1) with their chambers (2) in which intake pipes (3) communicate by means of intake valves (11). Each valve is returned to the closed position by a first spring (12). A second spring (13) which exerts an effect which is antagonistic to that of the first spring (12) is arranged on the other side of the valve (11). During the intake phase, a cam (14) pushes back a ball (15) which compresses the second spring (13), thus increasing the antagonistic force. When the piston (1) recoils, the residual pressure in the chamber (2) decreases until it falls below a value corresponding to the difference in the forces exerted by the two springs (12, 13). At that moment, the valve (11) opens. An abrupt drop in pressure, with a loss of power and consequently a noise during the operation of the pump, is avoided.
Inventors:
RUIIKUROODO PORERU
Application Number:
JP6429781A
Publication Date:
January 07, 1982
Filing Date:
April 30, 1981
Export Citation:
Assignee:
IDOURO RUNE RUDOUKU
International Classes:
F04B1/20; F04B1/053; F04B1/18; F04B7/00; (IPC1-7): F04B1/12
Next Patent: SLANT PLATE TYPE COMPRESSOR