HYDRAULICALLY DRIVEN INDUSTRIAL MACHINE

摘要

A hydraulically driven industrial machine has a variable displacement hydraulic pump for pressurizing hydraulic oil from a hydraulic oil tank; a actuator driven and controlled by oil that is discharged from the hydraulic pump and is supplied through a controlled valve and performing predetermined work; cooling means with a variable cooling rate function, the cooling means cooling return oil from the actuator and varying the rate of cooling of the return oil; load detection means for detecting work load by the actuator; and control means for varying the rate of cooling of the return oil according to the work load detected by the load detection means.