Hydraulic drive device
US6408622B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 24, 2000 |
| Grant date | Jun 25, 2002 |
| Priority date | — |
| Expiry date | Aug 24, 2020 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF15B2211/7135
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
A hydraulic drive system having a swing control system, includes a pump control unit for controlling a pump delivery rate such that a pump delivery pressure is held a predetermined value higher than a maximum load pressure among a plurality of actuators. Pressure compensating valves are each constructed to set, as a target compensation differential pressure, a differential pressure between a delivery pressure of a hydraulic pump and a maximum load pressure among the actuators. A pressure compensating valve for a swing section is given such a load dependent characteristic that when the load pressure rises, the target compensation differential pressure is reduced, the load dependent characteristic being set so as to provide a flow rate characteristic simulating constant-horsepower control of a swing motor.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.