Single rope winding double drum main hoist winch Replace drum steel rope liner is a common problem in daily maintenance work. If a wooden lining plate is used and a large amount of lifting winch is used, the lining plate will be replaced in an average of 2-3 years. Now the wooden lining plate has been gradually replaced by the engineering plastic lining plate. Compared to the wood lining plate, the engineering plastic lining plate is used. The cycle is 2-3 times longer, and the size of the liner must be calibrated before replacement. The plastic liner has high strength and poor plasticity. Once a large size difference occurs, the modification is much more difficult than the wooden liner, causing difficulties in installation and use. Therefore, before replacing the wood lining board with the engineering plastic lining board, we must do a good job in necessary measurement and proofreading work.
First, before the replacement should be carefully prepared in advance:
Before the replacement of the winch cylinder liner, some necessary preparations are required, including the length, number, and rotation of the liner, among which the more important is the verification work in two aspects. Of course, it is also difficult to solve the two problems after the problem. Happening:
1) Correctly judge the rotation of the lining rope groove.
Under normal circumstances, the double drum winch rope for the two sides of the rope into the rope (single twine winding double drum), judging the thread rotation is very easy to make such mistakes, as shown in the right hand thread spiral schematic diagram of the helical gear and ordinary The direction of rotation of the screw, if it seems that the rotation of the two parts should be the same, it is not right, using the left hand or right hand rule to determine the direction of rotation, there is a necessary condition, the thumb points to the center of the axis, and in the above figure The intersection between the centerline of the two parts and the thread is 90 degrees. We can evolve from left-handed and right-handed rules to a simpler method of judging the direction of the thread, that is, facing the centerline of the thread axis, the right high thread is right-hand thread, the left high thread is left-hand thread, in this way can It is easy to determine the thread direction of the two parts in the figure.
Further, we can determine the winding direction of the winch's two-yard drum. We found that the winding direction of the two-yard drum is the same, and the lower rope (the rope head connected to the cage is pulled out from under the drum) is the right forward threaded rope of the drum, and the upper rope is The reverse threading of the right thread, ie, the rotation direction of the rope grooves of the two drums is right-handed.
2) Measure the width and perimeter of the roller carefully. Measuring the width is to ensure the installation size, it is easier to measure, as long as the appropriate production and installation clearances, will not affect the installation of the liner. Measuring the circumference without measuring the diameter is because the diameter of the roller is difficult to measure. If indirect measurement is used, the data will have a large deviation and lose measurement and contrast. Measuring circumference can be directly measured with a tape measure. However, due to the long-term use of wood linings, most of the linings are deformed, and the measurement perimeter is relatively difficult. To measure more data, it is used to compare two rollers. The average perimeter is used as the basis for the production of new liners. Otherwise, no measurements or comparisons will be made and drawings will be directly made. This may result in difficulty in adjusting the drum and affect the normal operation of the winch.
Comparison of economic benefits:
After replacing the wood lining board with the engineering plastic lining board, the economic benefits obtained are still quite obvious. The first is the direct economic benefit: It takes about 25,000 yuan to make a set of 3 meters winch double drum wood lining board, and the manual installation cost is about 5,000 yuan. Buying a set of engineering plastic liners with the same specifications requires a capital of about 50,000 yuan. Due to the high strength of engineering plastics, it takes a long time to open the bolt holes. The installation time is longer than the wood liner, and the manual installation cost is about 8,000 yuan. In the capital, engineering plastic liners invest 28,000 yuan more than wood liners, but the service life of engineering plastic liners is much longer than that of wood liners. The life cycle of wood liners is about 3 years, and the service life of engineering plastic liners is not Below 9 years, the use of engineering plastic liners is equivalent to saving two pairs of wood liners, saving 60,000 yuan, compared with the beginning of more investment than the savings of 6-2.8 = 32,000 yuan.
There is indirect economic benefit. The engineering plastics have high strength and are not easily deformed, so that the winch wire rope can be in a relatively good stress state. Unlike wooden linings, they are easily deformed, causing uneven force on the steel wire ropes. The phenomenon of biting ropes and chaos is easy to occur after the rope grooves are worn, which is not conducive to the safe operation of the winch. Therefore, after replacing the engineering plastic liner, it also provides a powerful guarantee for the safe operation of the winch.
