As the most common use lifting equipment in the market, overhead crane has its own structure feature. Overhead main beam consists of three types, and it includes on track box shape main beam, partial rail box form, partial rail empty stomach box and single girder partial rail box form.
Rail way of hoist trolley of on track box shape main beam is fixed on the middle of main beam by orbital welding clamp. Except welding those main beam large plate, overhead crane beam structure of this kind can be used to weld small dense plate. The purpose is to keep the balance of main beam cover plate. The advantage of this technology is that has good manufacturing ability. Besides, main beam and end beam can weld automatically, thus will have a higher efficiency. While it also has shortage, because of welding, there are many welding line, which may cause big welding deformation of main beam.
Track way of partial rail box form in installed on the top of main pate of main beam. And the wheel pressure is on the main plate directly. Overhead crane structure of this form has a close depth-width ratio. The strength of main beam is higher than on track box girder, meanwhile inside of main beam leaves out small plate. So the welding deformation amount is small. Because the main beam is wide, it cannot wide a walking way on the side. So the top surface of main beam can play a walking way role.
Partial rail empty stomach box has the same structure as partial rail box. However, this girder structure adopts make holes on secondary plate. The reason why is that it can reduce the self-weight of bridge structure. In addition, it set electrical control system inside of main beam. Metallurgy overhead crane and foundry overhead crane use to use the design.
For the rest single girder main beam type, rail way of trolley set on one side of main beam, The other side weld an anti-roller way, when the rate loads is heavy, manufacturer will add an rail for anti-roller. This structure is not easy to check and main, except special environment need, it is not common.