Hydraulic drive system for construction machine
US9890801B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 17, 2014 |
| Grant date | Feb 13, 2018 |
| Priority date | — |
| Expiry date | Nov 26, 2034 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF15B2211/88
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
In addition to a main pump 102 having two delivery ports 102a and 102b and performing the load sensing control, two subsidiary pumps 202 and 302 for the load sensing control for respectively performing assist driving on a boom cylinder 3a and an arm cylinder 3b are provided. When driving the boom cylinder 3a or the arm cylinder 3b, a selector valve 141 or 241 is switched and flows of hydraulic fluid are merged together and supplied to the boom cylinder 3a or the arm cylinder 3b. When driving actuators other than the boom cylinder 3a or the arm cylinder 3b, only the hydraulic fluid from the main pump is supplied to the actuators. In short, the hydraulic drive system is configured so that two specific actuators having great demanded flow rates and tending to have a great load pressure difference between each other when driving at the same time can be driven with hydraulic fluid delivered from separate delivery ports. With this configuration, wasteful energy consumption due to pressure loss in a pressure compensating valve can be suppressed, and in cases of driving an actuator of a low demanded flow rate, the hydraulic pump can be used at a point where the volume efficiency is high.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.