During the using of overhead / gantry crane, mechanical parts, electrical control and hydraulic system would inevitable-ably have abrasion or damage. Reasons that cause same damage may not one-to-one correspond. Carefully analyze the fault, find out the real reasons and take corresponding measures to eliminate the fault. Thus, recover the technical performance of the fault point. The following are the common faults and solutions of overhead cranes:
|Fatigue crack on main web plate or cover plate.||Overload for long time.||When crack is less than 0.1mm, use grinding wheel to grind it. For bigger crack, drill φ8 holes at each side of the crack and open 60° on both sides of the groove, and veld. Reinforced repair welding shall be applied to the important stressed components to ensure their strength.|
|Wave-like distortion on web plate of main girder||Overload makes local part of web plate lose balance||Rectify with flame, remove distortion, eliminate internal stress with Hammer, strictly prohibit overload operation.|
|Side bending of main girder||Caused by overlaying of working stress, wrong transportation and storage.||Rectify with fire, heating the protrude parts of main girder and use some tools.|
|Main girder sinking distortion||Main girder structure tress web plate wave-like distortion effect wrong storage, transportation.||Adopt pre-stressing force to rectify, after flame-treatment, use channel steel to strengthen along lower cover plate of main girder.|
The next issue will summarize the common faults and handling methods of crane lifting mechanism.