发明名称 |
Volume control valve of variable displacement hydraulic rotating machine |
摘要 |
A volume control valve for controlling the volume of a variable displacement type hydraulic rotary machine includes a valve housing provided with a bore in which a spool slides axially to selectively establish and block communication of a pressure oil feed/discharge port with a high pressure port and a tank port. A first pressure receiving portion is formed in the spool to receive a load pressure as a pilot pressure introduced from a pilot port for displacing the spool axially within the bore. A bottomed axial bore is formed in the spool which has a slidable piston therein defining an oil chamber between the piston end and the bottom of the bore to receive a hydraulic reaction force induced within the oil chamber. A second pressure receiving portion is formed by the bottom of the bore to receive an internal pressure of the oil chamber, thereby changing a total pressure receiving area of the spool in conjunction with the first pressure receiving portion. An oil passage is formed in the spool at a position corresponding to the oil chamber.
|
申请公布号 |
US6389809(B1) |
申请公布日期 |
2002.05.21 |
申请号 |
US20010762325 |
申请日期 |
2001.02.06 |
申请人 |
HITACHI CONSTRUCTION MACHINERY CO., LTD. |
发明人 |
NIIDOME TAKASHI;KAGIWADA HITOSHI;KOBAYASHI TAKESHI |
分类号 |
F03C1/10;F04B49/00;F04B49/08;F16K3/26;F16K11/07;F16K17/30;F16K31/383;(IPC1-7):F15B7/00 |
主分类号 |
F03C1/10 |
代理机构 |
|
代理人 |
|
主权项 |
|
地址 |
|