Crane (Crane) belong to a lifting machinery, is a for loop, intermittent motion machine. A duty cycle comprising: means extract to extract the items lifted from, and then move to the designated place lower level items, followed by that extract unit returns home position for the next cycle. Typically Lifting the lifting mechanism (up and down movement of the article), run mechanism (with the lifting machinery moving), luffing mechanism and rotary mechanism (the article moved horizontally), plus metal body, power plant, steering control and the necessary auxiliary equipment combination. As used in bridge engineering lifting machinery, depending on its construction and performance, and can be divided into small light lifting equipment, lifting machinery and bridge type crane jib type three categories. Small light lifting equipment such as: jacks, hoists, winches and the like. Girder bridge type lifting machinery such as cranes, gantry cranes. Jib type crane as fixed rotary cranes, tower cranes, truck cranes, Shanghai cranes, tires, crawler cranes. Within a certain range vertical lifting and carrying heavy loads of horizontal multi-action lifting machinery. Also known as cable car. It belongs to material handling machinery. Working characteristics of the crane is doing intermittent movement, that in a work cycle Reclaimer, transport, unloading and other movements of the respective agencies are working alternately. Chinese ancient irrigated farmland is used orange boom cranes prototype. 14th century, Western Europe appeared human and animal drive rotary boom cranes. Early 19th century, the emergence of bridge crane; Crane important wear parts such as shafts, gears and spreader began to use metal materials, and began to use hydraulic drives. Late 19th century, steam-driven crane gradually replaced the water-driven crane. Beginning in the 1920s, the rapid development of the electrical industry and the internal combustion engine industry, electric motor or combustion engine power plant for a variety of crane shape. Crane hoisting mechanism mainly run institutions, luffing mechanism, slewing mechanism and metal structure. Hoisting mechanism is the basic working body of the crane, mostly by hanging system and winch composition, but also lift weights through the hydraulic system. Operation mechanism for horizontal transport of heavy or longitudinal adjustment of the position of the crane's work generally consists of motor, reducer, brake and wheel components. Luffing mechanism is equipped with only the jib crane, when the jib looked amplitude decreases, the amplitude increases when bent, sub balanced and unbalanced luffing luffing two. Boom slewing mechanism for causing rotation is determined by the drive means and the rotary bearing device. Metal structure is the skeleton of a crane, the main carrier such as bridge, boom and mast can be box-shaped structure or truss structure, but also for the web structure, and some can be used as a steel support beam. 1. Depending on the classification of the crane girder crane structure. In rectangular space and over the job, and more for workshops, warehouses, open yard loading and unloading goods, etc., have girder cranes, bridge cranes, gantry cranes, cable cranes, carrying bridges. Girder crane is divided into single-girder bridge crane and double girder bridge crane single girder crane bridge girders word to use more composite section steel and steel or steel type. Lifting the car often chain hoists, electric hoist or hoist lifting mechanism components as assembled. Press the bridge-bearing and suspended two. The former car beam bridge crane along the orbit; the latter at the plant along the suspension bridge truss crane orbit. Single girder crane sub-manual, electric two kinds. Lower operating speed manual single-girder bridge crane agencies, from the weight of too small, but the quality of their small, easy production, low cost, no power after a little time for carrying amount, less demanding on the speed and productivity occasions. Manual single-girder bridge crane with manual monorail car as the car is running, hand pull gourd as a lifting mechanism, bridge girders and by the end of the beam components. Main beam generally use single beam, side beam is formed by bending steel or steel welded. Electric single-girder bridge crane operating speeds, higher productivity than the manual, from the weight as well. Electric single girder crane from the bridge, traveling mechanism, hoist and electrical equipment and other components. 2. The bridge crane. Bridge crane bridge is a bridge crane runs on an elevated track, also known as the crane. Overhead crane lay on both sides of the bridge along the elevated track longitudinal run, lifting the car along the track laid on the bridge sideways, forming a rectangle the scope of work, you can take full advantage of the space below the lifting bridge materials, not hampered by ground equipment. Overhead Crane is widely used in indoor and outdoor warehouses, factories, docks and outdoor storage yard and other places. Bridge crane bridge crane can be divided into ordinary, simple girder bridge crane and metallurgical dedicated bridge crane three. General overhead cranes generally consists of lifting trolley, bridge run institutions, bridge metal structures. Lifting the car and consists of hoisting mechanism, trolley traveling agencies and small frame three parts. Lifting mechanism includes a motor, brake, reducer, drum and pulley. Motor through reducer drive the drum rotation, so that the rope around the drum or the roll down to lift weights. Small holder and mounting frame is lifting mechanism and trolley traveling agencies and other parts of the frame, usually welded structure. 3. cranes (jib crane) boom cranes Column, wall, balancing crane three forms. Column cantilever crane boom can swivel around a fixed base in fixed column, or cantilever column rigid connection with the transfer In the supporting base along the vertical centerline of rotation within the column and boom cranes with respect to the composition. It applies from the weight of small, circular or operating range service sector of the occasion. General machine tools and other artifacts for chucking and handling. Column cranes multi-use electric chain hoist as lifting mechanism and operation mechanism, less use of wire rope hoist and chain hoists. Job rotation and horizontal movement to use more manual, the use of electric only from the weight of only larger. Wall crane is fixed to the wall of cranes, or may be elevated track along the wall or other support structure on the operation of the crane boom. Wall row cranes using the occasion to span large building height larger workshop or warehouse, approached the wall near the lifting operations more frequently best. Multi-wall line and the top of the crane girder bridge crane or with the use of the service at close to the wall in a rectangular space, is responsible for lifting small light objects, large borne by the beam or bridge crane. Commonly known as balance balance crane hoists, it is the use of four-bar linkage principle to make the load and the counterweight constitute a balanced system, you can use a variety of spreader flexible and easily lifting loads in three-dimensional space. Balanced crane lightweight and flexible, and is an ideal lifting small items of lifting equipment, has been widely used in factory floor machine loading and unloading, inter-process, automatic line, production line of the workpiece, lifting sand box, parts assembly, and railway stations, docks, warehouses and other occasions 

keywords: Cranes, jib cranes, single-beam crane,