Crane is a kind of hoisting machinery, which is a kind of machinery for cyclic and intermittent motion. A working cycle includes: the picking device lifts the object from the picking place, then moves horizontally to the designated place to lower the object, and then performs the reverse movement to make the picking device return to the original position for the next cycle.
Usually, the hoisting machinery consists of a hoisting mechanism (to move the item up and down), a running mechanism (to move the hoisting machinery), a luffing mechanism and a slewing mechanism (to make the item move horizontally), plus a metal mechanism, a power device, and a manipulation control. and necessary auxiliary devices.
Mobile crane classification:
• Truck crane. The crane is installed on a general or special vehicle chassis, and the low-disk performance is equivalent to a truck with the same gross vehicle weight, which meets the technical requirements of road vehicles, so it can pass on all kinds of roads without hindrance. This kind of crane is generally equipped with two control rooms for loading and unloading, and the outriggers must be extended to maintain stability during operation. The range of lifting weight is very large, from 8 tons to 1000 tons, and the number of axles of the chassis can be from 2 to 10. It is the most productive and widely used crane type.
• Tire crane. The lifting part is mounted on a special pneumatic tire chassis. The same engine is used for getting on and off the vehicle, the driving speed is generally not more than 30KM/H, and the width of the vehicle is also wide, so it is not suitable for long-distance driving on the road. It has the function of hoisting and driving without outriggers and is suitable for hoisting operations in places with limited moving distances such as freight yards, docks, and construction sites.
• Off-road tire crane. It is a crane developed in the 1970s. Its lifting function is similar to that of a tire crane, and it can also be used for lifting and driving without outriggers. The difference is the structural form of the chassis and the improvement of the driving performance brought about by the unique chassis structure. The engines of this crane are mounted on the chassis, which has two axles and four large-diameter off-road tread tires. All four wheels are driving wheels and steering wheels. When transferring stations on muddy and uneven construction sites, all four wheels transmit power, that is, four-wheel drive, so as to improve the ability to pass through muddy ground and uneven roads. When driving at higher speeds on flat surfaces, only use the two wheels of the front or rear axle to reduce energy consumption. In the crane’s random file, 4×4 means four-wheel drive and 4×2 means that two of the 4 axles are drive wheels. This model is suitable for narrow site operations. It can realize continuous and stepless speed changes, and the engine will not turn off even in the case of sudden changes in road resistance, which greatly facilitates the driver’s operation. The all-terrain tire crane is a powerful and flexible tire crane with extended performance.
• All-terrain crane. It is a high-performance product with the characteristics of both truck cranes and rough terrain cranes. It can not only transfer quickly like a truck crane, and travel for a long distance, but also meet the requirements of working on narrow and rough or muddy grounds, that is, high speed, multi-axle drive, all-wheel steering, three steering modes, off the ground Large clearance, high climbing ability, and no need for outrigger lifting and other functions is a very promising product. But the price is higher, and it requires a higher level of use and maintenance.
• Special cranes. A special crane was developed to accomplish a specific task. For example, lifting wheel rescue vehicles mounted on off-road vehicles or armored vehicles for tactical and technical support for mechanized troops; road wreckers for handling traffic accidents, etc., all belong to this category.