In order to understand and design the hydraulic system of excavator, we must first analyze the working process of hydraulic excavator and understand the operation requirements of excavator. It is necessary to master the flow, force and power requirements of each hydraulic action element, the compound action requirements of the hydraulic action element matching each other, and the flow distribution and power distribution of the oil pump when supplying oil to each hydraulic element at the same time.
The following basic actions of walking are explained.
In the process of walking, it is possible to require the operation of hydraulic components to adjust. In the double pump system, one pump for left walking, the other pump for right walking, such as a hydraulic element action, so that a pump shunt oil supply, will cause, will cause one side of the walking speed reduced, affecting the straight-line driving, especially when the excavator loading transport or up and down truck walking, driving deflection will cause accidents.
In order to keep the straight line running, the oil supply system of the three pump system is supplied separately from the left and right, and the other pump is supplied with other hydraulic action elements. The double pump system is currently used in the following way :
1.One pump is supplied in parallel to the left and right, the other pump is supplied with hydraulic action elements, and the excess oil is supplied to the walking through a one-way valve.
2. Double pump confluence parallel to the left and right walking motor and operating device hydraulic components at the same time oil supply.