L68B3 Mast Section Maintenance technology summary of slewing bearing device of tower crane
Maintenance of slewing bearing device of tower crane
L68B3 Mast Section：
http://www.towercranesupply.com/product/l68b3-mast-section-for-tower-crane-masts
(1) the mounting support of the slewing ring (the seat on the lower bottom surface of the supporting ring gear and the seat on the upper surface of the inner ring gear) must be rigid enough and the mounting surface must be flat. Before assembling the slewing bearing, the bearing shall be stress relieved to reduce the deformation of the slewing bearing. During assembly, the contact surface between the support and the slewing bearing must be cleaned.
(2) pay attention to the change of noise and rotation resistance moment in use, and dismantle and check if there is any abnormal phenomenon.
(3) the slewing ring must be lifted or stored horizontally. Do not lift or store vertically to avoid deformation.
(4) before the bolt is fully tightened, the engagement inspection of the gear shall be carried out, and the engagement condition shall meet the requirements of gear accuracy: that is, the contact spots distributed on the tooth surface of the gear pair after running under slight braking shall not be less than 25% in the direction of the tooth height, and not less than 30% in the direction of the tooth length.
(5) sundries shall be removed once for 10 shifts of tooth surface operation, and lubricating grease shall be applied again.
L68B3 Mast Section：
http://www.towercranesupply.com/product/l68b3-mast-section-for-tower-crane-masts
(6) in order to ensure the reliability of bolt work and avoid the lack of bolt pre tightening force, the pre tightening torque of bolts shall be checked respectively after the first 100 hours and 500 hours of slewing bearing work. After that, the pre tightening torque shall be checked every 1000 hours of operation.
(7) high strength bolts and nuts are used to connect the slewing ring; double nuts are used to fasten and prevent looseness.
(8) when tightening the nut, the thread of the bolt and the end face of the nut shall be coated with lubricating oil, and the torque wrench shall be used to tighten it symmetrically and evenly in the circumferential direction for many times. During the last tightening, the pre tightening torque on each bolt should be approximately uniform.
(9) four oil cups are evenly distributed on the upper surface of the ring gear of the slewing ring aligned with the raceway, so as to add grease to the raceway. In general, the slewing ring is lubricated once every 50 hours. Add enough oil every time until grease seeps from the seal.
L68B3 Mast Section：
http://www.towercranesupply.com/product/l68b3-mast-section-for-tower-crane-masts
