ELECTRO-HYDRAULIC DRIVE SYSTEM FOR WORK MACHINE

摘要

PROBLEM TO BE SOLVED: To provide an electro-hydraulic drive system for a work machine, allowing efficient operation by fluid pressure and electricity, the system including a hydraulic motor for driving a structure of the work machine and an electric motor, and including a hydraulic pump driven by a power source and an electric motor.SOLUTION: This electro-hydraulic drive system for the work machine, which adjusts the flow rate of a hydraulic fluid by a control valve 6 and drives an upper rotating body 16, comprises: an electro-hydraulic pump 3 that has a hydraulic pump 4 driven by an engine 2, and a first electric motor 5; and an electro-hydraulic motor 9 that has a hydraulic motor 10 rotated by a hydraulic fluid supplied from the electro-hydraulic pump 3, and a second electric motor 11. The drive system includes a control device 7 that determines the operating states of the first electric motor 5 and the second electric motor 11 from the load on the electro-hydraulic pump 3 and the load on the electro-hydraulic motor 9.