Kobelco excavator multi-pump multi-path variable and quantitative mixing system is a new type of hydraulic system, which can make full use of the power of the excavator and make the excavator better suited to the requirements of various operations. SC-150 hydraulic excavator The multi-pump multi-channel variable-quantity mixing system used is shown in Figure 516. The system consists of two full-power variable axial piston pumps A and B with a flow rate of 2×110L/min and a quantitative flow rate of 43L/min Pump C consists of pump A driving left travel motor 8 through distribution valve group 7; pump B driving right travel motor 9 and swing motor 10 through distribution valve group 17; pump C driving boom cylinder 13 and arm cylinder 12 through distribution group 6 There are three positions with the bucket cylinder 1 as the valve 14: in the 0 position (the position shown), the oil from the distribution valve groups 17 and 7 is supplied to the oil cylinders such as the moving cylinder, the stick and the bucket through the confluence valve 15, and the rotary motor It can also operate simultaneously.At this time, there is always a fixed pump and a variable pump in the system to supply oil to the three working cylinders; when working in the 1st position, the pumps A, B and C do not merge, and each works independently, and the boom is lifted at this time. , Turntable rotation and excavator walking can be carried out at the same time; normal walking is also possible (because pump C does not merge with). The pressure of the fixed pump C can reach 40MPa, so the lifting capacity can be increased by 25%, and the heavy load lifting and falling speed can be kept constant for easy operation; when the working valve is in the 2 position, the confluence valves 15 and 16 are pushed to the left of the pump C The oil enters the pressure oil channels of pumps A and B, that is, the pressure oil of the three pumps is all supplied to the travel motor, so that the excavator has a faster travel speed.
In order to prevent the occurrence of suction phenomenon of oil pumps A and B, the system is equipped with a large displacement charge pump 3 independent cooling system 5 by two dedicated oil pumps to circulate the oil and get sufficient cooling, the speed limit valve 18 is It is used to limit the evenness of the excavator driving downhill to prevent slippage.
