Scraper conveyor is one of the essential key equipment in the normal production and operation of coal preparation plant, which plays the role of transportation and batching. In view of the shortcomings of the screw in the tail tensioning device of scraper worm gear in coal preparation plant, such as easy rust, high maintenance cost, high labor intensity when the chain is tight or loose, the optimization scheme of hydraulic control of the tensioning device is proposed, and good results are obtained in practice, which not only reduces the labor intensity of employees, but also reduces the labor intensity of employees. The operation level of mechanical and electrical equipment is improved, the maintenance cost is saved, and the self-control of scraper conveyor tight chain and loose chain is realized, ensuring the stable operation of production.
Scraper conveyor is a kind of continuous transportation equipment that uses scraper chain to transport bulk materials in the trough, and transports bulk materials by means of moving scraper chain. It is widely used in ports, docks, coal, mines and so on. When conveying materials, the scraper chain is all buried in the material. The scraper has simple structure, good sealing performance, convenient installation and maintenance, flexible process layout, not only can horizontal transport, but also can tilt or vertical transport, can be used single-machine, can also be used in combination, can be multi-point feeding, but also multi-point unloading. Because the shell can be closed, it can significantly improve the working environment of workers and prevent environmental pollution when the conveying volume is large, dusty and toxic high temperature materials. Scraper conveyor must have a large output power in transporting coal and blending coal. Therefore, the main engine is driven by the motor through the hydraulic coupler, reducer to transfer the power to the head sprocket shaft group system, drive the closed scraper chain for circulation, the bottom of the scraper is provided with discharge holes and turns according to the demand, to complete the function of coal transport and blending. The tensioning device is one of the key components of scraper conveyor, and its performance directly affects the stable operation of scraper conveyor.
In the process of starting, stopping and running, the scraper chain produces plastic deformation due to the instantaneous impact force generated when the motor starts, resulting in the scraper horseshoe ring and chain ring can not work properly because of slack. The main function of scraper conveyor tightening device is to ensure that the scraper conveyor chain is always perpendicular to the head and tail wheel, to ensure that the scraper chain and the head and tail wheel have a certain tension, will not occur because the chain slack and drift chain, broken chain, broken scraper and other phenomena. The specific functions of the tension device are:f
1) Ensure that the scraper conveyor tail wheel device has enough travel in the two directions parallel to the conveying material, ensure that there is a certain tensioning space between the chain and the head and tail wheel, increase the friction between the head and the tail wheel and the chain, ensure that there is enough driving force, prevent the scraper conveyor from jumping chain, sliding chain and other phenomena.
2) Ensure the minimum tension of the tensioning device, ensure the minimum gap between the scraper conveyor chain and the wear-resistant layer of the bottom plate, and prevent the occurrence of mechanical and electrical accidents such as chain breaking and motor burning caused by the uneven resistance of the wear-resistant layer of the bottom plate. Reduce the friction between the scraper, the chain and the wear layer of the bottom plate, improve the service life of the chain, reduce the useless power, increase the useful power back.
3) Compensate the plastic deformation of the scraper conveyor due to overload operation or excessive working conditions, timely absorb the plastic deformation of the chain link, adjust and tighten the scraper conveyor to maintain the minimum tension required by the scraper conveyor and the minimum friction between the chain and the head and tail wheel. Ensure the scraper conveyor is stable and normal operation circle.
4) To provide convenience for scraper conveyor minor repair, middle repair, overhaul and other processes. In the process of replacing scraper, chain, horseshoe ring, fastening bolt, bottom plate, wear-resistant layer, casting stone, etc., it is necessary to loosen the tensioning device first to ensure that the chain is in a relaxed state, providing convenience for maintenance and timely troubleshooting of equipment.
Scraper tensioning device is a step by step optimization, lifting, release labor, from manual to automatic process, its development and evolution process includes turbine worm tensioning device, positioning screw device, hydraulic system drive mode 3.
Turbo worm drive principle: the two axes of the worm drive cross each other vertically, the worm can be seen as a spiral with a tooth or several teeth around the cylinder along the helix, the turbine is like a helical gear, but its teeth are covered with the worm ④. When engaging, the worm rotates one circle, that is, drives the turbine to turn a tooth or several teeth, the worm and worm tensioning device uses the principle of turbo worm transmission, and finds that when there is loose chain in the scraper conveyor, the worm drives the turbine to rotate with an ordinary wrench, and the screw in the turbine rotating shaft drives the screw to rotate. Then the scraper conveyor is pulled or relaxed, so as to adjust the tightness of the chain.
The tail tensioning device is optimized from worm gear tensioning device to hydraulic system tensioning device, which greatly reduces the labor intensity of employees and saves equipment maintenance costs. Equipment failures caused by chain loosening, broken chain, jump chain, stuck chain, and drift chain have been reduced by more than 80%, significantly improving production efficiency and equipment service life, and ensuring stable operation of equipment and smooth production.