Self-propelled crane boom: description, specifications and types

For the mechanization of loading and unloading operations, the supply of structures and materials to the objects under construction, as well as to maintain the elements during their securing, an arrow crane is used - a load-lifting transportation machine in which the load-holding device is fixed on the end of the cargo beam or suspended on a cart moving along the boom.

Classification of jib cranes

Arrow cranes are divided into several types, depending on the scope and design features. It is customary to distinguish six types of equipment:

1. Self-propelled self-propelled crane, on which the boom is fixed on a mobile platform or running gear.
2. Portal is installed on a portal structure designed to skip transport.
3. Tower, which has an arrow fixed to a vertical farm, a tower.
4. The ship is installed on floating vessels for loading and unloading operations.
5. The mast, or derrick crane, has a vertical mast on which the boom is fixed.
6. The mounting boom is installed directly on the site, stationary, non-rotating.

Each instance of the boom is assigned an index, in which the main design features and technical characteristics are encrypted.

Mobile cranes

Among all groups of load-lifting machines, the most common are self-propelled gantry cranes, which are equipped with different propulsors depending on operating conditions and tasks. A wide distribution of this group of special equipment was provided:

• Self-contained drive;
• Mobility and high maneuverability;
• The ability to move with the cargo;
• High carrying capacity;
• The ability to quickly transport to another facility;
• Versatility - the ability to install various replacement equipment.

Self-propelled cranes have a replaceable boom, which allows you to change the parameters of special equipment and use it to perform various jobs. The mobile crane of the boom type is widely used for the construction of bridges and power industry facilities, as well as for loading heavy transport before its transportation.

Classification of jib cranes

The main parameters, according to which the boom cranes are divided into classes, are: load capacity, chassis type, drive design and technical features.

According to the type of running gear, special machinery is divided into several types:

1. Automobile - lifting equipment is installed on a motor vehicle.
2. The railway is mounted on platforms, moving along railroad tracks.
3. The crawler crane is moving on a crawler.
4. The pneumatic wheel is equipped with its own pneumatic chassis, controlled directly from the cab.
5. Rail is the same as the railway crane, but is self-moving along the line.

Some builders distinguish a tractor type, where the boom with lifting equipment acts as a replaceable attachments. This technique is used to perform work related to the movement of goods in off-road conditions.

Actuation of jib cranes

The main working element is the drive, which is responsible for the movement of goods. The most common is the crane boom with a mechanical drive type. In it, all components are driven by an internal combustion engine on diesel fuel or gasoline. Electric driven cranes are widely used in urban construction sites, where they are connected to electric lines. For autonomous operation, a diesel generator is required. In this regard, the city features became popular special machinery with hydraulic drive, where each machine mechanism is equipped with its own hydraulic engine.

In this case, the cranes are divided into single-engine, where all working units are driven by power plants operating on one shaft, and multi-engine, where each mechanism receives traffic from its own separate engine.

Boom construction

Depending on the design of the boom crane devices are of two types - telescopic and latticed. The first type of boom is a hollow box, inside which is located one or more extendable beams. If it is necessary to change the boom length, hydraulic cylinders extend telescopic elements. Such equipment is most often installed on cranes with hydraulic drive. Latticed arrows are divided into four groups:

• Rectilinear most common, are designed to solve a wide range of tasks;
• Curvilinear have an inflection, in the zone of which the hoist is mounted. Such arrows are used for moving bulky cargo;
• Stackable can increase their length by installing additional sections;
• Articulated - arrows, consisting of an inclined part and attached to it with the help of a hinge jib, which significantly increases the reach of the boom.

Each type of boom equipment is equipped with a flexible or rigid suspension. In the first case, the boom crane lifts the load with a system of ropes and pulleys, and in the second - with hydraulic cylinders.

Lifting capacity of jib cranes

The main quantity that characterizes the crane is its load-carrying capacity - the maximum mass of cargo that a crane can lift.
According to this parameter, special equipment can be:

• Light - up to 10 tons;
• Average - up to 25 tons;
• Heavy - more than 25 tons.

The value of the lifting capacity also includes the mass of the working equipment - load-gripping devices, grabs or electromagnets. The payload depends on the range of the boom, taking into account the stability of the machinery to rollover, as well as the strength of the working units.

Characteristics of jib cranes

GOST 22827-85 regulates the main characteristics and sizes, which can have self-propelled gantry cranes. Characteristics - the main parameters that determine the scope and purpose of special equipment. They are:

• Height - hook clearance from the tipping rib, boom length, depth of lowering and lifting height of the load-lifting equipment;
• Speed characteristics - determine the speed of lifting, turning the load, changing the reach of the boom, moving in the working state and in the prepared for transportation state;
• Tilt parameters - the calculated slope, which provides the possibility of moving the maximum heavy load along the vertical at all positions of the turning part;
• Indicators of the angle of rotation - the angle at which the special equipment can turn.

The same characteristics are applicable to the description of stationary boom cranes. For more detailed information, please refer to the appropriate GOSTs.