挖掘机液压系统安装了蓄能器,蓄能器的气室内填充有一定压力的氮气。发动机运转后,蓄能器气室里的氮气被压力油压缩,将压力能储存。当发动机熄火后,操作人员若操纵动臂或斗杆的先导阀,蓄能器内储存的压力能被释放。蓄能器内输出的压力油推动动臂、铲斗主阀芯移动,动臂、铲斗即可在自重的作用下放置于地面。蓄能器内的氮气还具有的缓冲 Excavator hydraulic system installed accumulator, accumulator gas chamber filled with a certain pressure of nitrogen. After the engine is running, the nitrogen in the accumulator gas chamber is compressed by the pressure oil and the pressure can be stored. When the engine is off, the operator can manipulate the pilot valve of the boom or arm to release the stored pressure in the accumulator. The pressure oil in the accumulator pushes the boom to move the main spool of the bucket. The boom and the bucket can be placed on the ground under their own weight. Nitrogen in the accumulator also has a buffer