What is a hydraulic crane?
In these cranes, power is transferred from one point to another through a fluid. An incompressible fluid that has its maximum density.
Unlike smaller cranes that work with electric or diesel engines, hydraulic cranes have an internal hydraulic system, which is full of liquid and allows lifting objects such as heavy containers, ships and tractors that are much heavier than the limit. It provides the features of any other crane device. In most hydraulic cranes, two gear pumps that work together are used. In single-engine cranes, the load is lifted with one engine, but in heavy cranes, which usually have two engines, one engine has the role of the driver and works to move the device, and the second engine is active as a lifter. Of course, in very heavy cranes, both engines are used at the same time to raise and lower the load.
Crane hydraulic repair:
Sometimes the mast of large or small cranes, or in other words, light and heavy cranes, are damaged or bent due to various reasons. In the initial investigations, it is necessary to check exactly how much the tonnage of the damaged crane is.
The tonnage of each crane is different, but because of this, its costs are variable, and the repair or replacement of its parts is also different.
For example, light cranes ranging from 1 to 5 tons can be diagnosed and fixed with their parts in the form of fabric, stock or at a more reasonable price. In crane hydraulic pump repair, a skilled expert can easily identify the problem of the device, replace or repair the corresponding part and impose the lowest cost on the owner of the device.
At first, the hydraulic repairman should know the parts and all the components of his crane in order to check it with full knowledge.
For example, one of the major problems in a crane or any hydraulic structure that needs to repair the crane's hydraulics is emptying its jacks. Of course, there are standards to maintain the safety of the vehicle and structure when emptying the jacks. For example, one-way valve is one of these standards. Of course, this cannot be the reason for emptying the valve of the crane, but checking it is not without problems.
In a two-way jack that is equipped with a valve on one side (pressure side), two factors can cause the jack to empty:
Jacking agent
1) Valve failure and oil return on the way in
2) Failure of piston packings and seals and oil leakage from the pressure side to the return side of the cylinder.
In both cases, the behavior of the jack is exactly the same and there is no difference in emptying the jack, but how can this issue be investigated?
It is obvious that in case of failure of the valve, the oil must be returned through the inlet duct, and the lower the volume of the jack, the faster the oil exits. To diagnose, it is necessary to open the jack and open the valve inlet hose. If there is a leak from the valve inlet, make sure that the valve is damaged. The boom is being tested, just place the mast at a 45 degree angle and attach the hook to a ready weight, then open the inlet hose and put the hose end in a tank or container because it is possible that the oil will come out. to be Then lift the load a little with a winch or telescope to test the jack. Under pressure, you can feel even the smallest leak by placing your finger on the inlet duct.
Also, if it is emptied without oil leakage from the jack valve, make sure that the fault is inside the jack and seals. Note that the hydraulic repair of the crane is very precise and sensitive, and the necessary points regarding the safety of the crane must be considered. The crane engine is also one of the things that can have problems and need to be repaired. which, unlike other diesel engines, requires experience and mastery and cannot be handled by general and beginner repairmen.