EXCAVATOR HYDRAULIC SYSTEM EQUIPPED WITH LOAD-SENSITIVE MAIN VALVE AND POSITIVE FLOW PUMP

摘要

An excavator hydraulic system equipped with a load-sensitive main valve and a positive flow pump comprises a main pump (1), a main valve (2) with a main valve core (21), and corresponding execution elements and auxiliary elements, and further comprises a regulating valve (3) for regulating the displacement of the main pump (1). The main pump (1) is a positive flow pump. The main valve (2) is a load-sensitive main valve. The output flow of the main pump and the suitable flow required for the work device are compared. When the output flow of the positive flow main pump is greater than the suitable flow for the work device, the output pressure of the regulating valve is reduced, and the displacement control pressure of the main pump is reduced, so that the displacement of the positive flow main pump is reduced, and the output flow of the positive flow main pump is reduced to the suitable flow for the work device. The system combines the positive flow hydraulic system and a load-sensitive hydraulic system and regulates the flow of a pump in real time according to the load, and therefore is energy conservative and has the feature of a high response speed.