Method for extending the service life of the mining shaft sheave pulley wheel of the ground mounted friction wheel hoist

1 Overview

The ground friction wheel hoist's mining shaft sheave pulley wheel is installed on the derrick. Due to inadequate maintenance and wear and tear during use, damaged bearing shells, bearings, and pads need to be replaced in a timely manner. For example, the JKMD4X4 floor friction wheel hoist has a self weight of more than 20 tons and usually needs to be removed and replaced from a tens of meters high derrick, which consumes huge manpower and material resources and affects the continuous production of the mine. The replaced Tianlun will be sent back to the manufacturer for repair. Due to its ultra-high height and width, transportation is difficult, and the repair cost will be around 300000 yuan. So how to extend the service life of the Tianlun, reduce maintenance costs and replacement cycles, is worth pondering. Based on years of experience in maintaining the crown wheel, problem oriented, this article introduces successful application methods from daily maintenance, improving bearing shells, replacing bearings, and replacing gaskets. It prevents and solves possible problems in advance, reduces the frequency of replacing the landing friction wheel hoist mining shaft sheave pulley wheel, and indirectly extends the service life of the landing friction wheel hoist mining shaft sheave pulley wheel.

Daily maintenance of 2-day rotation

According to the Coal Mine Safety Regulations, the mining shaft sheave pulley wheel of the ground friction wheel hoist must be inspected by dedicated personnel once a day. The manual for the use of the landing friction wheel hoist requires the pulley to be refueled at least once a week. In the daily maintenance process, due to the fact that the Tianlun is on the derrick, inspection is difficult and often overlooked, and the frequency and quality of refueling are also difficult to guarantee. This requires strengthening the maintenance and management of mining shaft sheave pulley wheel . Firstly, place an inspection record book on the celestial wheel, with the person who inspects signing it. The content includes the inspection time, participants, inspection content, inspection status, existing problems, and handling situation. At the same time, strengthen supervision, eliminate fraud, and ensure the maintenance time of Tianlun. Secondly, set up a dedicated refueling record book to record refueling time, grease name, refueling quantity, refueling personnel, and confirmation personnel, ensuring refueling cycle and refueling volume. Once again, establish maintenance standards for the Tianlun. Check the bearing temperature, sound, gasket condition, spoke condition, and crown wheel operation condition daily for any abnormal sounds and vibrations. Tianlun refueling should be done at least once a week, and the amount of refueling should be based on the oil output of the bearing shell. Check the grease condition of the Tianlun bearings once every quarter, and replace them in a timely manner if they deteriorate or emulsify. [2] In order to ensure the quality of maintenance, appropriate tools and equipment need to be equipped. mining shaft sheave pulley wheel refueling, if using a manual or pedal oil gun to refuel, is time-consuming and laborious, and sometimes it is not possible to add fuel. Using an electric refueling machine can achieve a convenient and fast effect. During winter refueling, it is advisable to add some light oil to reduce the viscosity of the lubricating grease. Secondly, the safety of mining shaft sheave pulley wheel maintenance is particularly important. When repairing the pulley, it is not allowed to work alone. It is strictly prohibited to climb the pulley ladder with tools in hand to prevent slipping. The tools used for maintenance should be placed in the tool kit. The guardrail on the derrick should be closed, with a height of not less than 1.2 meters. It is strictly prohibited to tie the safety belt to the pulley and steel wire rope during construction, and it must be tied to a sturdy guardrail. At least one emergency stop lock button should be installed on the mining shaft sheave pulley wheel platform to prevent the high-speed train from locking with the hoist. When pressing the button to lock the high-speed train, use a direct telephone to contact the driver in the garage. When there is no direct telephone, use walkie talkies or mobile phones to contact workshop drivers. The walkie talkie should be adjusted to the same dedicated frequency to avoid interference with walkie talkies at other work sites. When contacting personnel, a dedicated person should be designated in advance to be responsible for signal safety confirmation work. Before each call, names must be exchanged for confirmation. If the signal is unclear, high-speed trains are strictly prohibited.

Improvement of 3-day wheel bearing shell

When the original mining shaft sheave pulley wheel was manufactured, the traveling wheel bearings were designed as two half Bronze bushings for easy disassembly and assembly. However, in practical use, due to the presence of steel wire ropes in the pulley rope groove on the derrick, it is necessary to pull out the lifting rope from the rope groove and open the main bearing end cover when replacing the pulley Bronze bushings. This process is cumbersome, time-consuming, and labor-intensive, and the risk of high-altitude operations is high. The construction site space is limited, and it is rare to carry out bushing replacement operations on the pulley platform in China. Secondly, during the use of the two half bearing shells, due to the force of movement, the copper screws that fix the bearing shells are easily cut off, causing a noise every time the two half bearing shells rotate, exacerbating wear. Only by replacing the crown wheel can maintenance be carried out. For this reason, our company has designed the two half Bronze bushings as a circular whole tile, increasing the diameter and number of fixed copper screws, which can completely eliminate the problem of bearing shell noise and reduce severe wear. From experience and data, it can be inferred that using a full watt celestial wheel runs more smoothly and reliably, with a lifespan of over ten years.

4. Replace the mining shaft sheave pulley wheel bearing on the derrick

During the use of the mining shaft sheave pulley wheel, the bearings may have dents due to wear, quality, maintenance, and other issues. If the replacement of the mining shaft sheave pulley wheel is due to bearing issues, it may be a big deal. Therefore, the construction unit will only replace the mining shaft sheave pulley wheel bearings on the derrick. The specific construction steps are as follows. Construction preparation: According to the size of the bearings, weld a square heating box with a 10mm thick steel plate at a height that allows the hydraulic oil to completely submerge the bearings. Weld under the oil tank

Four bearings for easy movement on the derrick. Drill holes on the side below the fuel tank and install 4 3KW oil heating pipes to ensure no oil leakage. At the same time, weld a standing steel plate at the bottom of the fuel tank, 200mm higher than the heating tube, to ensure that the bearing does not touch the heating tube when placed inside the fuel tank. In order to have a clear idea, you can first pour hydraulic oil and place the bearing in the heating box for heating. Use an inside micrometer to measure the changes in the inner diameter of the bearing at room temperature, 60 degrees, 80 degrees, 100 degrees, and 120 degrees, in order to adjust the heating temperature according to the diameter of the crown wheel shaft. At the same time, prepare the tools for disassembling and assembling the bearing seat, as well as the tools and materials for the rope, lifting tank, and shed tank. Transport the bearings, heating box, and hydraulic oil to the wellhead one day in advance, and connect the power supply. Construction process: Use ropes to lift the tank at the wellhead or derrick and shed the tank, allowing the steel wire rope in the pulley rope groove to loosen as much as possible. Pay attention to the condition of the tail rope to prevent it from scratching the rope beam. Remove the upper cover and end cover of the pulley bearing, lift the pulley with a chain hoist, and leave enough space for removal. Gas cutting requires the removal of bearings to prevent damage to the shaft. Measure the outer diameter of the shaft after it has cooled down, and sand the shaft head with sandpaper. Place the shaft bearing in the oil tank without touching the heating tube. In order to have a clear idea, you can first pour hydraulic oil and heat the bearing to 120 degrees. When it is confirmed that the inner ring is larger than the outer diameter of the shaft head, use a chain block to lift the bearing. The construction personnel should wear gloves to align and push the bearing into place. If it cannot be pushed, prepare two copper hammers to strike from both sides of the inner ring of the bearing. After replacing the bearings, restore the crown wheel and steel wire rope. Using this method to replace the crown wheel bearing takes about 12 hours, with moderate construction intensity, saving 300000 yuan in costs compared to replacing the crown wheel during construction.

5. Replace the sheave pulley wheel insert on the derrick

Sheave pulley wheel insertcan reduce the wear of steel wire ropes and extend their service life. The main materials include ultra-high molecular weight wear-resistant pads, PP polypropylene plastic sheave pulley wheel insert, PVC sheave pulley wheel insert pads, nylon sheave pulley wheel insert, etc. Plastic sheave pulley wheel insert have poor wear resistance and short service life, but they are relatively easy to replace. They can be replaced manually with electric or pneumatic picks, and are now rarely used. Nylon pads and ultra-high molecular weight wear-resistant sheave pulley wheel insert have a service life of over five years,

But replacement is difficult. The traditional replacement method is labor-intensive and time-consuming, and sometimes the only way to replace worn pads is to replace the crown wheel. Using the turning method to replace the crown wheel liner takes about 10 hours.

The traditional replacement construction of the Tianlun pad is completed by workers using tools such as electric drills, electric saws, wind picks, and flat shovels. There are unsafe factors such as the need for a large number of personnel, high labor intensity, slow dismantling speed, and easy injury caused by impact parts. If working on the mining shaft sheave pulley wheel platform, there are also unfavorable factors such as poor working environment, high-altitude operation risks, and inappropriate positioning. Using turning to replace the mining shaft sheave pulley wheel liner is equivalent to "sharpening the knife without accidentally cutting wood", improving efficiency

Turn the old pad to the minimum thickness or even break it directly, in order to prepare adequately for later personnel to remove it.

Construction personnel can easily shatter and drop the cushion with a pneumatic pick, solving the problems of high work intensity, splashing and injuring people from impact parts, and small construction site space.

Firstly, utilize the space between the vertical steel wire rope of the pulley and the angle between the derrick to set up a temporary construction platform. Secondly, using the lathe holder with a turning drum liner, the cut and processed steel is welded onto the derrick, and the turning tool is perpendicular to the crown wheel liner. Process a cutting tool with a width of 6-8mm, run the winch at a speed of 0.5m, feed slowly, and cut a groove in the middle of the crown wheel pad until it reaches the root. After cutting the pads of several wheels, the traditional method was used to remove them with a pickaxe and replace the pad of the crown wheel smoothly.

6 Conclusion

The daily inspection and maintenance of the ground friction wheel hoist's mining shaft sheave pulley wheel is in place, and the Bronze bushings is improved. When the mining shaft sheave pulley wheel bearing is damaged, it can be directly replaced on the derrick or replaced with the mining shaft sheave pulley wheel liner by turning method, which can greatly extend the service life of the mining shaft sheave pulley wheel and reduce the replacement cycle. Compared with replacing the mining shaft sheave pulley wheel and returning it to the factory for major repairs, it saves time and effort, saves costs, and has significant economic benefits, making it highly valuable for promotion.