Standard Production Finished
Generally speaking, the camber of the main beam is 1/1000 of the crane span. There are 2 kinds of down-warping for the main beam: Elastic deformation which needs to be repaired in time; Permanent deformation needs reinforcement and repair.
The reasons cause the down-warping of the main beam:
Unreasonable material quantity and welding work;
Without considering the effect of high temperature on the material during design; Unreasonable operation and maintenance, for example, gas cutting and welding are not allowed above the crane main beam; And overload operation, unload the anchor bolt are also can cause the down-warping.
Down warping will cause damage to the shaft of long travel systems and produce an effect on trolley traveling. Deformation and cracks will appear on the steel plate.
There are 3 methods to repair the down-warping phenomenon: Flame correction on deformation place; Prestressing by brace force; Welding by a big current to heat and cool down.
It can be caused by the trolley-self and Railway.
For example: there are one or some wheels among the 4 wheels of trolley own different diameter with others; Unreasonable assembly of wheels; Too much tolerance among the wheels; Unreasonable trolley frame designing caused deformation;
There are sags and waves on the rail surface. There is too much tolerance on the joint of rail which needs to be less than 1mm;
Sometimes trolley wheel slip on the rail, it can be caused by following items:
Generally speaking, there should be some interval between the crane wheel rim and rail side; If not, there will be abrasion and swing when crane starts and stop. The main reasons are the following:
Sometimes when the crane be switched off, the brake will fail and cause the hook slip beyond the allowance number: V (rated lift speed)/100. There are some reasons: