Overhead crane

Overhead crane is a kind of lifting equipment which is horizontally erected over workshops, warehouses and stockyards for material hoisting. Because its two ends are located on tall concrete columns or metal supports, it looks like a bridge. The bridge of the bridge crane runs longitudinally along the track laid on the elevated on both sides, which can make full use of the space under the bridge to lift materials without being hindered by ground equipment. It is the most widely used and the largest number of hoisting machinery.
Bridge is a kind of bridge crane running on elevated track, also known as crown block. The bridge of the bridge crane runs longitudinally along the track laid on the elevated on both sides, and the lifting trolley runs laterally along the track laid on the bridge to form a rectangular working range, which can make full use of the space under the bridge to lift materials without being hindered by ground equipment. This kind of crane is widely used in indoor and outdoor warehouses, factories, docks and open storage yards.
Bridge crane is generally composed of bridge (also known as crane). It is composed of lifting mechanism, trolley, crane traveling mechanism, control room, trolley conductive device (auxiliary sliding line), crane main power conductive device (main sliding line), etc.
Bridge
Bridge is the basic component of bridge crane, which is composed of main beam, end beam, walking platform and so on. The main beam span is over the span, and there are box, split frame, web, circular pipe and other structural forms. Both ends of the main beam are connected with end beams, and walking platforms and safety railings are installed outside the two main beams. The walking platform on one side of the cab is equipped with a crane moving mechanism, and the walking platform on the other side is equipped with a device to supply power to the trolley electrical equipment, namely the auxiliary sliding line. A guide rail is laid above the main beam for the trolley to move. The whole bridge crane is dragged by the crane moving mechanism and moves on the guide rail along the length direction of the workshop.
Crane traveling mechanism
The crane traveling mechanism is composed of crane driving motor, transmission shaft, reducer, wheel and brake. There are two driving modes: centralized driving and separate driving. As shown in Figure 1.
Trolley traveling mechanism
The trolley is placed on the bridge guide rail and can move along the width direction of the workshop. The trolley is mainly welded by steel plate and is composed of trolley frame, trolley traveling mechanism and lifting mechanism.
The trolley traveling mechanism is composed of trolley motor, brake, coupling, reducer and wheel. The trolley motor drives the trolley driving wheel through the reducer and drives the trolley to move along the guide rail. Because the trolley driving wheels are close to each other, they are driven by one motor.
There are two transmission forms of trolley traveling mechanism: one is that the reducer is between the two driving wheels; The other is that the reducer is installed on one side of the trolley. The reducer is installed between the two driving wheels to make the torque borne by the transmission shaft more uniform; The reduction gearbox is installed on one side of the trolley, which makes installation and maintenance more convenient. As shown in Figure 2.
Lifting mechanism
The lifting mechanism is composed of lifting motor, reducer, drum, brake, etc. The lifting motor is connected with the reducer through the coupling and brake wheel. The output shaft of the reducer is connected with the drum winding the steel wire rope. A hook is installed at the other end of the steel wire rope. When the drum rotates, the hook rises or falls with the winding or release of the steel wire rope on the drum. For cranes with lifting capacity of 15t and above, two sets of lifting mechanisms are equipped, namely main hook and auxiliary hook.
It can be seen that the weight moves up and down with the rotation of the drum on the hook; As the trolley moves left and right in the width direction of the workshop, it can move back and forth with the crane in the length direction of the workshop. In this way, the movement of heavy objects in vertical, horizontal and longitudinal directions can be realized, and the heavy objects can be moved to any position in the workshop to complete the lifting and transportation task.
Control room
The control room is the pod for operating the crane, also known as the cab. There are crane and trolley traveling mechanism control device, lifting mechanism control device and crane protection device in the control room.
The control room is generally fixed at one end of the main beam, and a few are installed under the trolley and move with the trolley. A hatch leading to the walkway is opened above the control room for maintenance personnel to go up and down when repairing large and small machinery and electrical equipment.
There are three types of motion of bridge crane:
(1) The bridge crane is driven by the crane motor to move longitudinally back and forth along the tracks on both sides of the factory workshop.
(2) The trolley and lifting mechanism on the main beam of the crane are driven by the trolley motor to move laterally left and right along the track of the bridge main beam.
(3) The lifting motor (main hook and auxiliary hook) drives the weight to do vertical lifting movement.