In cranes, tower cranes, truck-mounted cranes and other lifting equipment, the slewing bearing plays a very important role. It can form a connection between the chassis and the upper structure of the machine, allowing the crane to rotate 360 degrees, while bearing the axial, radial and direction and overturning moment. The open design of the crane slewing ring allows the hydraulic system and other control components to pass through the slewing ring, making more efficient use of the limited space in the hoisting equipment.
As an important “joint” of the crane, the slewing bearing of the crane affects the performance of the crane and determines whether the crane can work normally and efficiently. Therefore, it is very necessary to properly maintain the slewing bearing of the crane.
The maintenance of the crane slewing bearingshould do the following:
(1) We must ensure that the mounting support of the slewing bearing has sufficient rigidity and the mounting surface is flat. Before the slewing bearing is installed, the bearing should be destressed to reduce the deformation of the slewing bearing. In addition, when the crane slewing bearing is installed, the contact surface between the bearing and the slewing bearing should be kept clean.
(2) The tooth surface of the slewing bearing should be regularly cleaned of debris and greased.
(3) After the first 100 hours and 500 hours of operation of the slewing bearing, the pre-tightening torque of the bolts should be checked respectively. After that, the preload torque should be checked every 1000 hours of operation. This can ensure the reliability of bolt work and avoid insufficient bolt preload.
(4) During the working process of the crane slewing bearing, it is necessary to pay attention to the changes in noise and slewing resistance moment. If there is any fault, it should be eliminated in time.
(5) When tightening the nut, lubricating oil should be applied to the thread of the bolt and the end face of the nut, and the torque wrench should be used symmetrically and evenly in the circumferential direction, and tighten it several times. The preload torque on each bolt should be approximately the same.
Details can be accessed here: https://www.excavatorbearing.com/a/bearing-knowledge/Maintenance-of-crane-slewing-bearing.html