发明名称 |
Hydraulic driving unit |
摘要 |
A hydraulic drive system includes a pump control unit 18 for controlling a pump delivery rate such that a pump delivery pressure is held at a predetermined value higher than a maximum load pressure among actuators 2-6. Pressure compensating valves 12-16 are each constructed to set, as a target compensation differential pressure, a differential pressure between the delivery pressure of a hydraulic pump 1 and the maximum load pressure among the actuators 2-6. The pressure compensating valve 12 is given such a load dependent characteristic that the target compensation differential pressure is reduced when a load pressure rises. A lower limit setting spring 55 for limiting the target compensation differential pressure from becoming smaller than a predetermined value is provided in the pressure compensating valve 12 for the swing section.
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申请公布号 |
US6397591(B1) |
申请公布日期 |
2002.06.04 |
申请号 |
US20000601518 |
申请日期 |
2000.08.02 |
申请人 |
HITACHI CONSTRUCTION MACHINERY CO., LTD. |
发明人 |
TSURUGA YASUTAKA;KANAI TAKASHI;KAWAMOTO JUNYA;NAKATANI KENICHIRO;TAKAHASHI KIWAMU;HAMAMOTO SATOSHI;OKAZAKI YASUHARU;NAGAO YUKIAKI |
分类号 |
E02F3/34;E02F3/96;E02F9/12;E02F9/22;F15B11/04;F15B11/16;(IPC1-7):F15B13/06 |
主分类号 |
E02F3/34 |
代理机构 |
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代理人 |
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主权项 |
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地址 |
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