FAQs

How to solve the main beam down-warping phenomenon?

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.

How to solve the unsmooth traveling of the trolley?

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:

1. The start it too fast;
2. There are oil and frost on the rail;
3. Too much tolerance of the rail’s height or crane wheel oval phenomenon;
4. Unbalanced wheel load pressure; Or small wheel load pressure of 2 driving wheels.

How to solve the unreasonable abrasion phenomenon of the crane wheel?

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:

1. Unqualified wheel production cause speed difference;
2. Skew wheel caused by the unprecise assembly, or frame deformation.
3. The difference between driving wheels makes crane deformation;
4. Rails adjustment and maintenance;
5. The difference in the interval of the gear;

How to solve the work failure of the brake?

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:

1. Too much longer work time cause the axis pin and brake block wears out;
2. The bad quality of mainspring and unreasonable handling of temper and quenching causes the spring wears out.
3. The brake wheel circular runout beyond the technical demand.
4. Some additional staff under the heavy load limiter of brake makes the brake torque reducing.