Title:
【発明の名称】液圧システム
Document Type and Number:
Japanese Patent JP2521658
Kind Code:
B2
Abstract:
A variable displacement pump has a swashplate (14) controlled by a pair of pistons (16, 18). A shuttle valve (36) communicates the highest pressure pump workport (10 or 12) to an operator-controlled displacement control valve (24). A pressure-responsive override valve (63) is connected in series between the displacement control valve and the pistons. When an override pressure is achieved, the override valve blocks communication of the control valve with the pair of pistons and communicates the pump workports directly to the pistons for rapid reduction of pump displacement. A neutral bypass valve (90) is formed out of a sleeve (28) of the displacement control valve to bypass control pressure to sump when the displacement control valve is in neutral. A pressure-reducing valve (90) limits the pressure acting on the stroke control valve to limit response rates and reduce erosion. The override valve includes orifices (76) which, in intermediate positions, provide flow rate control of the fluid flow to the swashplate control pistons.
Inventors:
BURATSUDOREI DENBAA GUUDEERU
Application Number:
JP1980385A
Publication Date:
August 07, 1996
Filing Date:
February 04, 1985
Export Citation:
Assignee:
DEERE & CO
International Classes:
F04B1/30; F04B49/08; F04B49/00; (IPC1-7): F04B49/00
Domestic Patent References:
| JPS5236282A |
Foreign References:
| DE2342786A1 |
Attorney, Agent or Firm:
Kyozo Yuasa (4 outside)