Troubleshooter
I will discuss about feed pressure circuit highlighted in below diagram.
This type of hydraulic system comprises of a variable displacement hydraulic pump, a feed pump with individual relief valve and external filter, electric motor, fixed displacement hydraulic motor, a maximum system pressure cut off valve, double proportional solenoid valve on the pump control, a brake controlled solenoid 3/2 valve, relief valves on main pumps lines.
The hydraulic system of the stabilizing winch is connect with the hoisting winch system of the crane
Is a close circuit that consists of a pump and a hydraulic motor that are link with each other via lines. The flow rate and flow direction are control by variable displacement pump servo cylinder.
Task of feed pump
The task of the feed pump is to fill the circuit with oil when starting the system. When system is fill with oil the pump pressure will determine the leakage within circuit. To compensate for this leakage a feed pump is in use.
Therefore feed pump vacuums oil from common tank fill and replace the hot fluid leaking from the closed work circuit. The feed fluid is put through check valves into the low pressure side of the system. Different circuits operate at different pressures. Setting of exact feed pressure is specified in the instruction book.
On diagram shown the pressure of the feed pump is regulate at individual relief valve.
System put to work
When system is ruining, a working pressure that is determined by the magnitude of the load is build up in one of the hydraulic lines. The working pressure closes one of the check valves. The circuit replenish during operation, oil enters through the check valve at the return side which is maintain at feed circuit pressure.
The post is filled under Hydraulic Diagram
