Hydraulic drive system
US6584770B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 12, 2001 |
| Grant date | Jul 1, 2003 |
| Priority date | — |
| Expiry date | Aug 30, 2022 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF15B2211/75
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
In a hydraulic drive system in which a target compensated differential pressure for each of pressure compensating valves 21a, 21b is set in accordance with a differential pressure between a pump delivery pressure and a maximum load pressure, and a target LS differential pressure is set as a variable value depending on a revolution speed of an engine 1, a fixed throttle 32 and a signal pressure variable relief valve 33 are disposed in a maximum load pressure line 35. A relief setting pressure PLMAXO of the signal pressure variable relief valve 33 is set so as to satisfy PLMAXO=PR−PGR+a (where a is a value smaller than PGR) with respect to a target LS differential pressure PGR and a setting pressure PR of the main relief valve 30.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.