Flow sensing based variable pump control technique in a hydraulic system with open center control valves
US9133605B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 27, 2012 |
| Grant date | Sep 15, 2015 |
| Priority date | — |
| Expiry date | May 7, 2034 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T137/2605
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
A hydraulic system has a variable displacement pump that sends fluid from a tank into a supply conduit from which separate open-center control valves convey the fluid to each one of a plurality of hydraulic actuators. The control valves have open-center orifices connected in series between a bypass node and the tank, thereby forming a bypass passage. Pressure at the bypass node controls displacement of the pump. A valve arrangement is connected between an outlet of the pump and the bypass node and is responsive to an amount of fluid flow through the supply conduit to the plurality of hydraulic functions, wherein as the amount of fluid flow increases, the valve arrangement causes fluid flow to the bypass node to decrease. Thus the pressure at the bypass node varies as a function of the operation of the control valves.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.