Hydraulic drive system for construction machine
US9845589B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 19, 2013 |
| Grant date | Dec 19, 2017 |
| Priority date | — |
| Expiry date | Apr 25, 2034 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF15B2211/7142
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
In a hydraulic drive system performing the load sensing control by using a pump device having two delivery ports whose delivery flow rates are controlled by a single pump controller, surplus flow is prevented and energy loss at an unload valve and a pressure compensating valve is reduced in combined operations in which two actuators are driven at the same time while producing a relatively large supply flow rate difference therebetween. A boom cylinder 3a is connected so that the hydraulic fluids delivered from delivery ports P1 and P2 of a pump device 1a are merged and supplied to the boom cylinder 3a. An arm cylinder 3h is connected so that the hydraulic fluids delivered from delivery ports P3 and P4 of a pump device 1b are merged and supplied to the arm cylinder 3h. A travel motor 3d is connected so that the hydraulic fluid delivered from one (delivery port P2) of the delivery ports of the pump device 1a and the hydraulic fluid delivered from one (delivery port P4) of the delivery ports of the pump device 1b are merged and supplied to the travel motor 3d. A travel motor 3e is connected so that the hydraulic fluid delivered from the other (delivery port P1) of the delivery ports o…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.