As we all know, the steel beam is an important part of the double girder crane. It determines how much load-bearing the overhead crane and gantry crane can carry. So what faults will the steel beam of the double-beam crane appear usually? What are the forms of damage?
Surface corrosion (interpretation: refers to decay, disappearance, erosion, etc.). The working environment of the double girder crane is harsh. It usually works in gas dust (form: solid particles) containing acid-base corrosion (interpretation: refers to decay, disappearance, erosion, etc.). In addition, the collision during operation and the natural aging and peeling of the anti-rust coating make the surface lose its protection.
In addition, maintenance work of the double girder crane is not timely, resulting in partial corrosion and oxygenation, varying degrees of surface rust, reducing the strength of steel beams, and making steel knots for a long time. Structural deformation, which is also a common fault in the main girder of a double-beam crane.
Practice has proved that although crane main girder cracks do not necessarily lead to fractures, it is very important to find and deal with them in time. Even if it is not repaired in time, long-term work is often the initial stage of cracks, especially the transition period and dangerous cracks. Generally speaking, cracks mainly occur in the welding part and the part where the stress is concentrated.
The deformation of double girder overhead crane and double girder gantry crane includes partial bending (Bend) deformation, twisting and eccentricity. According to the metal structure inspection requirements, the straightness tolerance of the rod along the longitudinal axis is 1/750. The double girder crane deformation of the main chord in use should not be more than 3 permille; -5 permille;; the deformation of the web should not be more than 2-4mm; the hole distance error of the rod connecting bolt (composition: head and screw) should not exceed the assembly (assemble) 1/2 of the gap; and the roundness error of the screw hole does not exceed 1/2 of the assembly gap; when it exceeds the above range, it is deemed to be deformed.
The reasons of double girder crane steel beam deformation are as follows:
1. The limit switch, height limiter, and each interlocking mechanism are formed during lifting. The performance is normal, safe and reliable.
2. Requirements for main components: The opening size is less than 15% of the original size, and the torsion deformation is less than 10%; the wear of the plate hook bushing is less than 50% of the original size, and the wear of the plate hook mandrel should be less than 5% without peeling or repairing. Welding, burrs, hook hangers, pulleys have no obvious defects
3. The amount of wear and corrosion on the surface of the steel wire rope should be less than 40% of the diameter of the steel wire, and the wire should be less than 10% of the total number of wires at a certain distance. Burning, twisting of dead corners, annealing phenomenon
4. No cracks in the drum, no loose connection and fixation; the wall wear of the drum is less than 20% of the original wall thickness; the safety roll is not less than 2 turns, the diameter ratio of the drum and the wire rope should meet the requirements, and the balance wheel should be in good condition.
Dejun Crane is a professional double girder overhead crane and double girder gantry crane supplier, and we can design and customize the double girder crane according to your working condition and requirements with good quality and competitive price. Therefore, if you have need about the double girder crane, please contact me freely. Ruby@dejunindustry.com or leave a message below. Any of your question on the double girder crane will be replied within 24 working hours.
