Combine overview. What to do yourself and what to outsource?

By drzwioknarzeszow23/12/2022557 Views

The weather isn't giving up, so there's still time for the final inspections of the combine before harvest. We suggest what you can do yourself, and what a factory service visit will be useful for in the case of modern, several-year-old combines.

The article was published in the monthly Farmer No. 7/2018

Modern combines are efficient and provide comfortable working conditions for the operator, but their servicing is also demanding. Nevertheless, many activities can still be done on your own - this applies primarily to the general mechanics of the vehicle. Others require qualified mechanics, their knowledge and tools.

CUTTER TOOL

Starting the inspection of the machine from its front, you can independently check and assess the condition of the cutter: blades (razor blades), fingers and cutter head. In the case of knives, when their edges are dull and rounded (no teeth), they should be replaced. The same is true of fingers. A blunt cutterbar scythe will cause undercutting, and thus - "pulling" the grain and will prevent, for example, increasing the mowing speed. The process of replacing the knives should be facilitated by the increasingly popular fixing them with screws, not rivets.

It is also very important to accurately position the cutter bar in relation to the tine bar. In the extreme positions of the scythe, the axes of the razor blades should coincide with the axes of the fingers. In order to prevent the scythe from breaking off during the harvest, it is also worth verifying the scythe drive system for any looseness. To do this, check the wear of the joint bushings, as well as the condition of the cutter head. A symptom of looseness in the drive of the scythe is also the noisy operation of this element.

Considering the cutterbar, if the auger coils are bent, they need to be straightened and damaged or broken auger fingers replaced. You can also check the incline conveyor on your own. The condition of the chains (whether they are stretched out) and the beams must be assessed. Worn elements, as in the case of a scythe, need to be replaced. Alternatively, if the beams are slightly crooked, they can be straightened. It is also worth checking the stone catcher and emptying it if it is full. Failure to do so may cause stones to enter the further circulation and as a result, e.g. damage the drum of the thresher.

THRESHING MACHINE

You can also verify the threshing unit yourself. First of all, check the condition of the drum and concave. If the threshing drum bars have worn ribs or are damaged, they must be replaced. When assessing the "wear" of the flails, you can use a new element and compare the degree of wear with it. Signs of flail wear can also be "beating" on the drum. Please note that flails are exchanged in opposite pairs. After replacing the rasp bars, it is recommended to balance the threshing drum. This operation is performed on a special balancing machine after removing the element from the shearer and must be outsourced to a service or workshop. An unbalanced threshing drum can cause the entire harvester to work unevenly and vibrate. It is worth balancing the drum after each disassembly, e.g. if it has been damaged by a stone and it is necessary to straighten some element.

It is also worth ordering the service center to replace worn bearings of the threshing drum due to the need to tighten them with a certain force, i.e. using a torque wrench.

CLEANING TEAM

Relatively simple activities that can be carried out by yourself when inspecting this part of the machine include: sieve verification Check that they are not rusted, clogged, bent or killed. If they are slightly bent, you can try to straighten them.

Another step is to check the grain pan: that it is clean and that there are no loose joints. An obligatory point is to check the condition of the straw walker suspension and the condition of the straw chopper knives and, if necessary, turn or replace them.

DRIVES AND LUBRICATION

Harvester users may also be tempted to assess the condition of drive belts. For this purpose, it is best to loosen the tensioner of each belt, remove it and assess its condition (if it is not cracked, excessively stretched, etc.). After removing the belt, move the pulley, paying attention to possible play (including axial play) and noise in the bearings. It is also worth checking each chain. If it is still loose despite maximum tension, shorten it. An overstretched chain will not adhere well to the sprocket. For accurate verification of chain condition, you can also measure the distance between the pins of a pair of links (inner and outer) and compare it to the value on a new chain. It is assumed that the elongation of the chain can be up to 3%. its length. It is worth remembering that when replacing the chain, the sprockets must also be replaced.

One of the absolute duties of users of harvesting machines is thorough lubrication of moving joints in accordance with the recommended intervals. New machines have lubrication point diagrams and lubrication intervals indicated on the labels located on the inside of the flaps and on the labels attached to each caliper.

Engine, hydraulic or gear oils as well as filters should be replaced at the intervals provided in the combine harvester manual. In the case of engine oil, you should always follow the rule of changing it every mileage or once a year - even if the machine does not reach the required hours. If you undertake to change the oil in the hydrostatic system, remember to drain the oil not only from the tank, but also from the lines and the lowest positioned hydraulic motor. In order to perform the operation accurately, the piston rods of the cylinders should be retracted. The procedure for changing the oil and possibly bleeding the system is described in the instruction manual.

SENSORS CAN BE WRONG

The sensors of the combine working units must be calibrated in order to work efficiently. The sieve position sensors, the gap between the drum and the concave, the moisture and grain loss sensors should be calibrated. At first glance, the word "calibration" may sound threatening, but in practice it turns out to be an easy thing to do by every combine user. Tips found in the owner's manual will be helpful here, as well as training for operators conducted by dealers. Sensor calibration is performed from the combine control monitor panel. After entering the appropriate menu option, e.g. bottom sieve, the system opens the bottom sieve to the maximum, and then closes it completely. If the process is successful, a confirmation message will appear on the display. Of course, it may happen that the calibration of the sieves fails, for example because the sieve cannot close completely, for example. This does not necessarily mean a serious fault, because the cause may be residual dirt (that is why the inspection of the sieves described above is so important) or a poorly adjusted control rod.

Automatic settings, however, should not release you from the obligation to personally verify that the settings are correct. And so it should be checked whether, for example, the opening of the sieves at 6 mm, shown on the display, is actually such a value in reality, whether the concave gap is the same as given by the computer, etc. In the case of grain loss sensors, which are mounted in the form of plates , it is enough to clean them from time to time with a cloth and check the connections of the wires.

Damaged sensors can be successfully replaced on your own. These items cannot be repaired or regenerated. The information about the sensor damage is a properly working element, and a message about its failure is displayed on the control panel. The service will certainly be needed in many cases after machine failures to erase any errors displayed on the monitor from the control unit.

In the case of modern combines equipped with, for example, sensors that monitor grain quality (damage and contamination), such as cameras that are part of the ICA2 system of John Deere S700 series combines, the manufacturer does not require any interference when it comes to system calibration. However, you should remember to clean the windows behind which the cameras are hidden before the season, and then from time to time during the harvest. There is also no need to calibrate the new generation Activ Yield weighing system. However, it must be remembered that, as a rule, in the scales used so far - also by other manufacturers - such an operation should be performed by entering the net weight of grain from the first trailer on which it was poured in the computer settings.

TAKE CARE OF WORK COMFORT

As service technicians notice, care for the operator's workplace is often a neglected issue, but it is very important for the health and well-being of the machine operator. A well-rested operator is much more efficient and effective. Checking the condition of the cabin filters is a breeze compared to other service activities carried out on the combine. The cabin filters can be cleaned by blowing compressed air in the opposite direction of suction. If an element is extremely dirty or damaged, it should be replaced.

What you cannot do on your own is air conditioning service consisting in refilling the refrigerant or possibly repairing the system. Cleaning and fumigation of air conditioning can be easily carried out by yourself, with the help of generally available preparations.

SUMMARY

It is always worth to carry out at least a general verification of the harvester on your own. Even with a little mechanical knowledge, simple tools and a manual, many minor repairs and adjustments should not be difficult. It is worth knowing, however, that the arrival of the factory service for a general inspection of the harvester does not involve shocking costs, especially if such an action is carried out before the season. A trained eye, ear and computer with a diagnostic program will allow the service technician to quickly detect any faults and irregularities that can still be removed in advance.