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Truck Crane

Truck Crane

Truck Crane

Truck Crane 
A crane is a lifting machine equipped with a winder, wire ropes or chains and sheaves that can be used both to lift and lower materials and to move them horizontally. It uses one or more simple machines to create mechanical advantage and thus move loads beyond the normal capability of a human. Cranes are commonly employed in the transport industry for the loading and unloading of freight; in the construction industry for the movement of materials; and in the manufacturing industry for the assembling of heavy equipment.
The most basic type of mobile crane consists of a truss or telescopic boom mounted on a mobile platform - be it on road, rail or water.
A crane mounted on a truck carrier provides the mobility for this type of crane. Generally, these cranes are designed to be able to travel on streets and highways, eliminating the need for special equipment to transport a crane to the jobsite. When working on the jobsite, outriggers are extended horizontally from the chassis then down vertically to level and stabilize the crane while stationary and hoisting. Many truck cranes possess limited slow-traveling capability (just a few miles per hour) while suspending a load. Great care must be taken not to swing the load sideways from the direction of travel, as most of the anti-tipping stability then lies in the strength and stiffness of the chassis suspension. Most cranes of this type also have moving counterweights for stabilization beyond that of the outriggers. Loads suspended directly over the rear remain more stable, as most of the weight of the truck crane itself then acts as a counterweight to the load. Factory-calculated charts (or electronic safeguards) are used by the crane operator to determine the maximum safe loads for stationary (outrigger) work as well as (on-rubber) loads and traveling speeds.
Lifting capacity
Cranes illustrate the use of one or more simple machines to create mechanical advantage.
The lever. A balance crane contains a horizontal beam (the lever) pivoted about a point called the fulcrum. The principle of the lever allows a heavy load attached to the shorter end of the beam to be lifted by a smaller force applied in the opposite direction to the longer end of the beam. The ratio of the load s weight to the applied force is equal to the ratio of the lengths of the longer arm and the shorter arm, and is called the mechanical advantage.
The pulley. A jib crane contains a tilted strut (the jib) that supports a fixed pulley block. Cables are wrapped multiple times round the fixed block and round another block attached to the load. When the free end of the cable is pulled by hand or by a winding machine, the pulley system delivers a force to the load that is equal to the applied force multiplied by the number of lengths of cable passing between the two blocks. This number is the mechanical advantage.
The hydraulic cylinder. This can be used directly to lift the load or indirectly to move the jib or beam that carries another lifting device.
Cranes, like all machines, obey the principle of conservation of energy. This means that the energy delivered to the load cannot exceed the energy put into the machine. For example, if a pulley system multiplies the applied force by ten, then the load moves only one tenth as far as the applied force. Since energy is proportional to force multiplied by distance, the output energy is kept roughly equal to the input energy (in practice slightly less, because some energy is lost to friction and other inefficiencies).
Stability
In order for a crane to be stable, the sum of all moments about any point such as the base of the crane must equate to zero. In practice, the magnitude of load that is permitted to be lifted (called the "rated load" in the US) is some value less than the load that will cause the crane to tip.
Standards for cranes mounted on ships or offshore platforms are somewhat stricter due to the dynamic load on the crane due to vessel motion. Additionally, the stability of the vessel or platform must be considered.
For stationary pedestal or kingpost mounted cranes, the moment created by the boom, jib, and load is resisted by the pedestal base or kingpost. Stress within the base must be less than the yield stress of the material or the crane will fail.
We have XCMG Truck Cranes, lifting capacity from 8T to 130T. Model QY8D, QY12, QY16C, QY16D, QY20B, QY25E, QY25K (Pilot), QY25K (Mechanical), QY25K5, QY30K5, QY40K5, QY50B, QY50K, QY60K, QY70K, QY100K, QY130K.
The features of QY25K5:
1,Standard 3-axle truck crane of the most advanced performance in China with the technology and quality achieved as 30t class in foreign country.
2,First introduced the concept of 25t class with 5 boom sections, main boom length 38.5m and jib length 8.3m, and the lifting height for boom and jib is at the advanced level of international same type of cranes.
3,Main load-bearing structural parts are made of high strength steel. Application of octagonal boom profile and reasonable setting of half or fully extended boom section contribute the crane powerful load lifting capacity.
4,Hydraulic system adopts serial items of China State Patent and serial items of technical innovation, so that the whole machine features strong power, energy-saving and high efficiency.
5,Swing system with free-sliding function can automatic align to load, offset pinion makes meshing clearance easy to adjust, less impact and smooth operation.
6,Well-equipped with perfect safety devices such as load moment limiter (LML), hoist limit switch, rope-end limiter, safety control valve, hydraulic pressure protection valve, anti-cavitations and anti-blocking device, etc, make operation more reliable.
7,Environmental, energy-saving and powerful engine offers strong drive for the crane carrier and improves travel performance for the whole machine.
8,Spacious and beautiful operator s cab, equipped with adjustable seat, newly-designed air-conditioning system, etc. all present the concept of "People Coming First".

XCMG Truck Crane