HYDRAULIC DRIVE OF SINGLE-BUCKET POWER SHOVEL WITH DISCHARGE DEVICE Russian patent published in 1994 - IPC

FIELD: building and mining machinery. SUBSTANCE: hydraulic drive of single-bucket power shovel with discharge device has hydraulic pump connected with pressure hydraulic line and hydraulic control valve unit. Control space of hydraulic control valve unit communicates with one of control spaces of first spool and with its input. Output of control valve communicates with control space of second spool and, through restrictor, with return hydraulic line. Other control space of first spool is connected with input of second spool which communicates with servocontrol hydraulic line and with control space. Output of second spool communicates with control space of hydraulic control valve unit through check valve. EFFECT: enhanced reliability of operation. 1 dwg