As a Tower Crane Manufacturer, share with you. When repairing parts of the the working mechanism of the tower crane, the fasteners such as bolts, screws, nuts,
spring washers, cotter pins and keys must be checked at the same time to
determine whether they can continue to be used or replaced.
The bolts used in tower cranes can be divided into two categories: shear bolts and tensile bolts. The connecting bolts of metal structures are mostly shear bolts. Some tower cranes, such as QT80, QT80, etc., are bolts that are tension bolts. The function of the shear bolt is to ensure that the position of the bolt is unchanged, and it will not produce axial movement. It is generally made of 35 steel, and the tensile bolt is mostly made of 40CR steel.
Mobile Luffing Tower Crane
The common defects of bolts are: bolt breakage and abrasion; the screw thread is crushed and crushed, the screw head is damaged, the shaft is bent, and the corner of the nut is crushed.
Threads should have correct tooth shape, no defects, clean surface, and no rough burrs. The nut sleeve should fit closely on the screw and be easy to tighten without loosening.
If there is a large gap in the bolt connection, it indicates that the connection has been loosened, weakened, or damaged and must be replaced immediately.
The crushed thread can be repaired with die. The repaired thread shall not have burrs, and the outer diameter shall not be 0.2mm larger than the standard. The crushed part of the bolt end can be cut off.
If the thread part of the tensile bolt is damaged or the corner of the nut is severely squashed, it must be scrapped. When the deflection of the shear bolt exceeds 0.2 of the total length of the bolt, it shall be scrapped. Nut breakage, weakened threads and flattened corners should also be scrapped.
When disassembling and inspecting the spring washer and cotter pin, in principle, all should be replaced with new ones. Can not be replaced with ordinary iron wire. Damaged, deformed and crushed keys must be replaced. Do not use keys with large gaps or pad in the gaps.
Mobile Luffing Tower Crane regular quantitative lubrication precautions
The lubricating oil should be placed in a clean container, and care should be taken to prevent dust, dirt, and water from entering the lubricating oil. Regular and quantitative lubrication is required.
Insufficient lubrication has little effect; excessive lubrication not only causes waste but may also have a negative effect. For example: excessive rolling bearing lubricating oil will make the bearing heat. When filling grease through the oil cup, when there is butter overflowing at the mouth of the oil cup, it indicates that the amount of grease injected has exceeded the saturation amount.
Our company also has 10 T Top Kit Tower Crane on sale, please contact us.