Motorized Hydraulic Orange Peels Grabs Maintenance

Motorized Hydraulic Orange Peels Grabs Maintenance

Kinocrane is a grab manufacturing expert in the world, we have very rich experience in cranes and grabs maintenace. Orange Peel Scrap Grabs and motorized hydraulic grabs are suitable for the below maintenace steps.

l .Oil change and liquid level check

The first oil change should be performed after 500 hours operating time from the first successful commissioning. In the future, the oil will be changed after 1000 working hours. After the above 2 steps oil changes, the oil will be changed once a year (working hours are 8-10 hours a day).

The medium selection, generally when the environment temperature is above 0, chooses YA-32~YA-64 hydraulic oil (original 20# -40#)，and if the temperature is lower, which mean temperature near to 0℃ and above 0℃ , chooses the oil grade smaller is better. conversely chooses oil grade bigger. If the working environment temperature is below 0 C, low coagulated hydraulic oil or aviation hydraulic oil should be selected. The Viscosity range of oil should be 10 - 33 cm.

In the process of oil change, firstly put the grab in the open state, horizontally on the ground, open the vent hole (ie screw out the oil measuring rod), then screw off the oil drain plug, release the oil in the fuel tank, drain the oil After the plug is cleaned, reinstall it well. The new oil poured into the tank must be filtered. If condition is available, use filter is better. If filter is not available, you can use the attached oil filter of the grab. After the tank is filled, the oil filter and the oil measuring rod should be installed well. Before the grab is closed, oil level checking is necessary.

The oil level checking requires the grab to be placed in the open state. The grab must be placed horizontally on the ground, the highest and lowest oil levels are read on the oil measuring rod. Too much oil will cause overpressure in the fuel tank. Too little oil will cause the hydraulic system and the series-excited DC motor to rotate too high, which may cause damage to the oil pump and motor.

When the fuel tank needs to be replenished, be sure to fill the same type of oil in the fuel tank. Do not use some other types of oil.

2 .Lubrication instructions

Each lubrication point on the grab is marked with a blue mark, hanging the splicing bolt and the cylinder. The dumpling bolt is added with lubricant once 2-3 weeks. The claws of the grab must be added once a day. It will be better if the lubricating oil containing lithium base oil.

3.Oil filter

When the grab is used for the first time and the work time is around to 50hours, the oil filter should be cleaned one time. And then every 200 working hours, it should clean it again. In addition, when the hydraulic equipment or cylinder is put into use after repairing, the oil filter should also be cleaned. The oil filter is equipped with a magnetic filter device. Always clean the magnet pins during the cleaning process and then install them.

4.The grab overhaul

(1) When performing maintenance, switch off the power of the grab, and after each flash disassembly or overhaul, re-measure the pressure of the hydraulic system.

(2) Hydraulic Grab petals overhaul.

First, put the grab in the open status and place the lower support frame on the bracket. This will eliminate the force on the hinge bolt. Then, remove the claws of the grab petals and the cylinder, and then disassemble and hinge the frame of the support frame. After all the bolts have been removed, check whether the dumpling bolts and bearing sleeves are worn. If the parts are worn out seriously, they should be replaced with new ones. After all the repairs, install the grab in order.

(3) Maintenance of the cylinder

After the cylinder is running for a period of time, the common fault is that the oil leaks from the outside of the piston rod. The main reason is that the seal ring on the rod is worn or scratched. For the V-shaped seal, it can be compensated by compressing the axial clearance, that is, tightening the lock nut. If the oil still leaks, you need to replace the seal.

The cylinder is disassembled like the grab petals. Firstly disassemble the dumplings with the grab petals, and then disassemble the dumpling bolts with the support frame. If you need to replace the oil seal or seal, first unscrew the cylinder lock nut and then from the cylinder. Pull out the piston rod, remove the piston, and replace the oil seal or seal (see Figure 6 for the cylinder structure)

Overhaul of the cartridge-type integrated control valve block: First remove the left and right covers, then pull out the unit components. When you pull out the unit components, do not break the unit components. The pilot relief valve can be directly screwed down with a wrench. When unloading the main valve unit assembly of the relief valve, first unscrew the hexagon socket screw plug, and then pull out the unit assembly of the main valve. After the unit components are all removed, the unit can be inspected. Check whether the seal is damaged. Then check that the valve sleeve is matched by grinding. Therefore, the valve core and the valve sleeve cannot be interchanged. In principle, the sealing ring requires a new one when it be disassembled once. After each component is repaired, it is required to be seriously cleaned and assembled again (see Figure 7 for the integrated control valve structure).

After all the grab are overhauled, the system pressure needs to be re-adjusted again. When adjusting them, the pressure measuring device should be installed on the oil circuit distributor, and then the adjusting screws of the two pilot relief valves should be released. Then turn on the power, and slowly increase the voltage when adjusting voltage. At the same time, observe the reading on the pressure gauge and adjust it to the pressure value specified on the nameplate of the grab. After the pressure adjustment is completed, please tighten the pilot valve lock nut to prevent the pressure setting value from changing due to vibration. During the pressure regulation process, if the grab petals vibrates when the grab is closed, this moment adjust the adjusting bolt of the check valve SV2 until the vibration stops, and then tighten the fixed nut. Note that when adjusting the hydraulic control check valve SV2, the rated pressure value cannot exceed 200bar（The grab rated pressure bar）, which will cause the working medium to heat up, reducing the grab output and affecting the closing time of the grab.