Selection of tower crane

Contents

Design Task

1. Description of tower crane and principle of its operation

2. Statistical calculation for crane working stability

3. Construction of crane load characteristic

4. Statistical calculation for the crane's own stability

5. Selection of crane lifting mechanism rope

6. Selection of lifting mechanism motor

7. Description of safety precautions during crane operation

Conclusion

List of literature used

Description of tower crane and principle of its operation

Tower crane - a rotary crane with an arrow fixed in the upper part of the vertically located tower.

The main parameters of the tower crane: lifting capacity, departure, cargo lifting height, cargo lowering depth, cargo lifting (lowering) speed, tower turning speed, crane moving speed.

The tower crane consists of the following main units: a tower, a running frame with wheels, a supporting-turning device, a turning platform with a cargo and boom winch, with a counterweight; turning and electrical equipment mechanism, load lifting mechanism, departure change mechanism, crane movement mechanism, etc.

The crane tower serves to maintain the boom at a certain height, as well as to transfer loads from the boom to the running frame and crane tracks. The tower is made of metal corners or pipes, sometimes there are towers made in the form of a solid pipe .

The running frame serves to transfer active loads to crane tracks.

Crane is provided with hook to grip load. Weights are held with the help of removable load-gripping devices - universal slings of steel - and hemp ropes, chains, crossarms, cases, grips, special hooks and containers. Steel ropes also serve for tooling as traction elements when lifting the load and the boom itself. They are used in devices for mounting and dismantling cranes, for extending the tower, moving the cargo trolley on beam booms, for turning the crane.

Inside the cockpit there is control equipment for the crane mechanisms - command controllers, departure and lifting capacity limiter, anemometer measuring panel, emergency switch, lighting board, fans, fire extinguisher and signal lamps. There are special places for storing first-aid kits, clothes, and tools, for electric cooking and storing a crane magazine.

All working movements of the crane are carried out using four mechanisms: a movement mechanism, a turning mechanism, a cargo winch, a trolley (with beam booms) or a boom (with lifting booms) winch.

The crane path must have grounding, inventory dead ends. Near the crane track there should be a control load (as a rule, these are heavy reinforced concrete blocks), which systematically monitor the serviceability of the crane load limiter.

Production technology: initially the crane is transported to the construction site: heavy cranes - large knots, and many modern models - entirely on rolling pneumatic axles. Next, the BC is installed in various ways: lifting the tower using a crane boom or a special mast, lifting the tower with the subsequent installation of the boom and sectional increase in the height of the tower. Then the crane operation is started to move and lift the necessary elements by means of control from the cockpit.

Conclusion

During the calculation of the course work, the structure of the tower crane with a rotary platform was studied, the design of the working equipment and the location of the main units of the machine were described.

- Maximum load capacity mmax = 15.1 t is obtained from the condition of crane load stability.

- Found coefficients of crane intrinsic stability at different boom flights. kc. lips <1.4. This crane is not stable. Additional self-sustainability activities are required.

- Selected rope for lifting mechanism with diameter of 18 mm (according to GOST 268880), having a breaking force of less than 1370 MPa (steel rope of LCR type, 6x19 wires with one organic core).

- Selected MTH 71110 type motor with rated power of 100.0 kW and rotation speed of 584 rpm.

56.dwg