How can tower crane rental enterprises master the maintenance technology, installation and maintenance of slewing bearings for tower cranes

The installation support of the slewing bearing must have sufficient rigidity and the installation surface should be flat. Before assembling the slewing bearing, the support should undergo stress relief treatment to reduce the deformation of the slewing bearing support. When assembling, the contact surfaces between the support and the slewing bearing must be cleaned thoroughly.

During the maintenance and operation of tower cranes, attention should be paid to the changes in noise and rotational resistance moment. If any abnormal phenomenon is found, disassembly and inspection should be carried out.

Slewing bearings must be lifted or stored horizontally. Do not lift or store them vertically to avoid deformation.

Before the bolts are fully tightened, the meshing inspection of the gears should be carried out, and the meshing condition should meet the requirements of gear accuracy:

That is, after the gear pair operates under slight braking, the contact spots distributed on the tooth surface in the height direction of the gear teeth are not less than 25%.

Not less than 30% in the length direction of the gear teeth;

The tooth surface should be cleared of debris once after 10 shifts of operation and relubricated with grease.

To ensure the reliability of the bolt operation and avoid insufficient bolt preload, the preload torque of the bolts should be checked respectively after the first 100 hours and 500 hours of operation of the slewing bearing. The preload torque should be checked every 1000 hours of operation thereafter.

The bolts and nuts connecting the slewing bearing all adopt high-strength bolts and nuts for tower crane maintenance, and are fastened and anti-loosening with double nuts.

When tightening the nut, apply lubricating oil to the thread of the bolt and the end face of the nut. Use a torque wrench to tighten it symmetrically and evenly multiple times in the circumferential direction. When tightening for the last time, the pre-tightening torque on each bolt should be approximately uniform.