Cranes are actively used at construction sites, they serve to lift loads, as well as to move them. The crane operation consists of several cycles. This is the seizure of the cargo, the working stroke of the crane - the cargo is moved and unloaded, idle to return to the place where the cargo is received.
The most important characteristic of a crane is its lifting capacity - the maximum weight that it can lift. These mechanisms differ both in their design and in the field of application.
Types of crane
There are several classifications of cranes.
If possible, they can be moved: mobile, stationary, lifting, circular. The mobile crane moves around the terrain with the help of special devices, the stationary does not have a self-propelled element and is attached to the base of the platform, the rising crane can be lifted up and down with the help of its mechanisms. Due to its design, the circular crane moves in a circular direction.
According to the device, there are shooting, bridge, rope cranes and stackers. Jib cranes are a boom or trolley, to which a load-gripping body is suspended, moving along the boom. The overhead crane has a bridge with a trolley moving along it. Stackers - cranes with a vertical column and a device for storing goods. Cranes with supporting ropes have ropes fixed in supports instead of a bridge
By the type of drive, cranes are distinguished with an internal combustion engine, with a hydraulic, electric and manual drive. Models with an internal combustion engine operate on the electrical network of the engine, which is included in the design. An electrically driven crane has an AC or DC motor in the device. The hydraulically driven crane has a low efficiency. Hand-operated models are used for a small amount of work.
According to the degree of rotation, there are rotary and non-rotary models. The first ones have a special arrow, which rests on a movable or stationary column, or on a turntable. Such devices are installed on a rail or trackless track. Fixed cranes are of span type and do not have a full circle
According to the method of installation, a movable, radial, mobile and trailer crane is distinguished. The first is installed on the base and can be moved from place to place. The radial crane has the ability to move relative to one stationary support. The mobile crane moves freely during operation. The towed crane has a mechanism for moving and moving in the trailer behind the tug.
By the type of load-gripping mechanism, there are hook, magnetic, pin, grab, landing, well crane. The hook crane is a hook-shaped load-gripping device. The magnetic crane is equipped with an electromagnet. The grab crane has a grab (device for grabbing goods). The pin valve is equipped with a gripper for removing the pin from the electrolyser. The landing crane has a column with horizontal pliers at the bottom to grip the workpieces into the furnace. The well valve is designed for servicing well furnaces.
The purpose of the crane
Cranes are mainly used in various enterprises. This is a completely irreplaceable and useful technique. With its help, heavy loads are lifted to a great height and moved to the right place. The crane is an indispensable technique for finishing and roofing works. It is actively used in construction for the installation of panel walls and block foundations.
In addition, cranes are used in ports and warehouses to move goods. No foundry and machine shop can do without a fixed overhead crane.
Very often, owners of private houses use a homemade crane. These are simple mechanisms that do an excellent job with the assigned tasks. These devices have a large lifting capacity and a boom length of 8 - 9 m. The simplest such crane consists of supports, a boom, a lifting mechanism, and a counterweight.
A crane is a functional device that is required in many places where work with heavy loads and materials is carried out. This device greatly facilitates work and saves time spent.