First, avoid screw connection, riveting loose after welding

Due to the poor working environment of the combine harvester, loosening may occur during the use of some parts such as the bolts of the traveling mechanism, the cutter assembly, and even the riveting. During maintenance, some of the pilots did not deal with scientific methods. Instead, they took simple countermeasures to solve the problem. For convenience, the loose parts were welded. Although this treatment can temporarily be urgent, it is not reliable. Practice has proved that this disposal method has the following disadvantages:

1, cover up potential problems, leading to more failures

The moving blade and the stationary blade are fixed on the blade holder by riveting, and it is not easy to loosen under normal circumstances. If there is looseness, there must be a reason. Should carefully check the movement of the tool holder, whether there is collision, block, analyze, rule out other influencing factors before handling. Avoid headaches, treatment, foot pain, ignore other potential problems, blindly welding the blade, notice that this will cause a lot of trouble. The moving tool holder is a thin and long rod, which will generate warpage due to local heating and cooling during welding. Minor deformation can still be corrected. If it is a multi-point welding, deformation is more serious and it is difficult to correct. As a result, the tool holder cannot maintain its normal working condition due to deformation, resulting in stuck and mutual interference between the upper and lower blades, which aggravates the wear of the tool holder, the pressure blade, and the V-shaped guide groove. Because of the warpage of the tool holder, the blade gap is difficult to adjust as required, making A series of failures such as poor cutting performance are reproduced.

2, increase the difficulty of maintenance, which is time-consuming and time-consuming

The running mechanism is eroded by mud, so that the lubricant in the bearing shell is easily deteriorated. If the bearing is poorly protected, it needs to be disassembled and cleaned and replaced. If only to prevent the wheel from coming off, the locking nut on the shaft end is welded to the shaft, so it is difficult to dismantle it during maintenance. When the blade is welded to the knife holder, it is troublesome to remove the old one if the blade is damaged. In order to prevent the shaft end lock nut from falling out of the wheel, in addition to not leaking washers, it is also possible to replace the original design flat washer with a 1.5 to 2 mm thin sheet metal gasket, which can help prevent the nut from automatically withdrawing. .

3, causing unnecessary parts damage

The parts where the walking machine is relatively easy to cause problems, such as timely inspection and maintenance, can reduce the early wear of the parts in the mechanism and prolong the service life. After the nuts and shafts are welded, it is inconvenient to dismantle them, and the interior can not be cleaned and filled with new lubricating oils in time, thereby aggravating the wear of the bearings, shaft housings, oil seals and axles. Even if some parts have not yet reached the level of scrapping, once it is dismantled, damage will be inevitable. For example, the wheel axle can still be used, but because of the welding with the nut, in order to remove the wheel, the shaft must be cut in a destructive way. Waste can be imagined.

4, changed the rational design, affect the use of

Taking the Huzhou-130 combine harvester as an example, the double-layer vibrating screen rear screen is inclined in the fore-and-aft direction. The angle of tilt plays a role in controlling the amount of loss after the row of grass is blown out. The harvesting operation needs to be based on crop conditions and takes into account losses. Quantity and impurity rate are adjusted. On the left and right side plates of the tail screen, several small holes with different angles are arranged in an arc shape for adjusting the inclination of the tail screen. Some robots welded the left and right fixing bolts to the side plates so that the tail screen could not be arbitrarily adjusted and fixed at an angle, destroying the original design and affecting the use effect. This is also undesirable.

Second, avoid the drive belt and chain to maximize tension

When the combine harvester is working, it is wrong to loosen the belt and chain, but too tight is wrong. Because the belt is driven by friction, there is inevitably a relative slip between the belt and the pulley, resulting in slippage and loss of power, which is also an overload protection measure. The looser the belt, the more slippage, the greater the power loss. The greater the belt tension, the smaller the slip and the lower the power loss. However, if the tension is applied to the ambassador's drive shaft, the radial force will increase, which will aggravate the belt wear and reduce the service life. In severe cases, the drive belt will bend and break. The method for determining the tension of the belt is as follows: the hand is pressed down forcefully in the middle of the belt, and the deflection is preferably 10-20 mm, and the center distance between the two transmission shafts increases with a larger value. There is no slippage in the chain drive, but if the tension is too small, the impact load will be large and the chain will break easily. Excessive tension increases the additional force on the shaft and the bearing, which can easily cause bending of the journal and breakage of the links. The correct degree of tension should be: forcefully pull the middle of the loose edge of the chain and there should be a deflection of 20-30 mm.

Third, avoid replacing the rubber bushes do not grasp the timing

After several years of use of the Model 1065 combine harvester, parts such as screen box poles, screen box brackets, grain screen booms and other components often break. The rupture of these parts was initially suspected of welding being unqualified, but fractures still occurred after the new parts were replaced. After careful inspection and analysis, it turns out that many rubber bushings in the screen box drive mechanism wear out after several years of use, causing gaps between the parts, reflecting a greater displacement on the screen box, and up and down, left and right asymmetry, resulting in A lot of unbalanced movements damage the relevant parts. Some of them replaced the new rubber bushes, but due to the wrong replacement method, the rubber bushes were prematurely worn. Some of the crops were congested with grain and the screen box was deformed.

Replace the timing of rubber bushings. When the rubber bushing is installed, the screen box can not be replaced in any position. Only when the screen box is in the neutral position, it is equivalent to the position where the piston of the engine is at top dead center or bottom dead center, and the rubber sleeve can be replaced. Because the rubber bushings are not exposed to any side forces at this time, side pressure will occur during installation, which will cause early damage to the rubber bushes. Turn the draft wheel so that the connection between the theoretical center of the connecting rod and the center of the crankshaft and the center of the screen box shaft is 90, indicating that all the rubber bushings are in the neutral position.

When replacing a rubber bushing, you should also pay attention to the following issues:

(1) Replace the rubber sleeve from the screen box. Do not change the installation sequence at will. The rubber bushings on the left and right sides of each part should be tightened in steps of 1 to 10 according to the instruction manual.

(2) Only use water when installing rubber bushings. Do not use grease, lubricating oil, talcum powder, etc.

(3) Before installing the rubber bush, make sure the shaft is free of oil, paint, and dirt.

(4) When the screen box is in the neutral position, use a wooden wedge or other tool to fix it so as not to move the screen box.

(5) Ensure that the distance between the center, parallel and the left and right side walls of the screen box is equal.

(6) Rubber bushings should be loaded with minimal twisting and mounted with special tools.

(7) Check and test run after loading.

In order to prevent damage, you can weld a lacing in the screen box to increase the strength of the screen box.

Health Daily Care

Ganoherb International Inc. , http://www.ganoherb.us