The main components of the steel structure of the MG type double main girder gantry crane are composed of the main beam, end beam, support beam, outrigger, lower beam, balance beam (no tonnage hour), small frame, and so on. These parts can be made of section steel (truss type) or steel plate (box type). The running mechanism of the cart is composed of wheels, reducers, motors, and brakes. Both sides are driven separately. The running mechanism of the trolley is composed of wheels, reducers, motors, and brakes. Generally, a centralized driving hoisting mechanism is adopted, and a special reel mechanism or a hoist can be used. The electric hoist can also be used to lift. The total power supply form of the crane can be overhead soft or hard sliding wire type, or cable reel type.
I don't know if the MG double girder gantry crane you mentioned is the same type as what I have come into contact with. Let me tell you about the structure of double-girder gantry cranes in general, and the structure of MG double-girder gantry cranes that I know.
Electric double-girder gantry crane: It is composed of cart running mechanism, lower beam, outriggers, driver's cab, main beam, trolley running mechanism, lifting mechanism, escalator, electrical appliances and other components. Let's briefly introduce it below. It is mainly composed of a lower beam and a trolley. The trolley is composed of a driving wheel set and a driven wheel set. The operating mechanism includes a motor, a reducer, a gear, and a wheel set. The steel is used as the material, and then welded into a cage structure, the lower end is connected with the lower beam, and the upper end is connected with the main beam bolts through flanges. The frame is made of section steel, the shell is welded on the frame with thin steel plates, the driver's cab is closed with broken lines, and the electrical appliances, power distribution cabinets and lines of the operating mechanism are generally located in the driver's cab. The shaped steel and the steel plate are welded together, usually welded into a truss triangle, and on the main girder, there are trolley running rails.
The main components of the trolley running mechanism are similar to those of the trolley. The motor is driven by a reducer, and the small gear on the reducer is then transmitted to the large gear, so that the trolley can travel back and forth. The lifting mechanism is installed on the trolley frame, and the lifting movement is realized through the winch and the supporting fixed pulley, movable pulley or hook.
MG type double girder hook gantry crane structure:
The double-girder hook gantry crane is composed of a bridge frame, a cart running mechanism, a trolley, and electrical equipment. The bridge frame adopts a box-type double-girder welded structure, and the traveling mechanism of the cart is driven separately, and all mechanisms are operated in the control room. The conductive form of the gantry crane is divided into two types: cable and sliding wire, and the user can choose one. MG type double-girder hook gantry crane is suitable for loading and unloading in open warehouses, stockyards, railway freight stations, port terminals, etc. It can also be equipped with a variety of special hooks for a variety of special operations. The environment for normal use of this series of cranes should be within the range of -25°C to +40°C, and the average temperature within 24 hours should not exceed +35°C. The altitude of other installation and use sites shall not exceed 2000 meters, and the motor capacity shall be checked if the altitude exceeds 1000 meters.