Field solution: Russian high-strength tractors will speed up harvesting

Russia has improved one of the key components of agricultural machinery — on-board gearboxes for tractors. Engineers have identified the weaknesses of previous models, optimized the geometry of the parts and replaced the material from which they are made. As a result, the safety margin of the gearbox has almost doubled, and its service life has doubled. The development can also be adapted for other vehicles, such as road construction vehicles and loaders.

How the tractor design was improved

In the world of agricultural machinery, machine reliability is a factor that determines the success of planting or harvesting operations. To increase this resource, scientists and engineers from the Don State Technical University (DSTU) have improved the design of the on-board gearboxes of the front axle for a range of domestic tractors. These units play a key role in ensuring productivity by converting engine speed into powerful wheel movement, the experts explained.

— These mechanisms play a key role in ensuring tractor performance, especially on difficult soils. Initially, the task was born within the framework of import substitution: Canadian tractors began to be produced under license in Russia. But the analysis showed that the original gearbox did not have sufficient strength for our conditions," Vladislav Pigenko, one of the developers and director of the advanced engineering school of DSTU, told Izvestia.

According to him, using a mathematical model, experts identified the vulnerable elements of the mechanism and optimized them. As a result, the geometry of the supporting elements of the satellite bearings — small gears that transmit torque — and the shape of the gearbox cover were changed.

— Improvements were achieved primarily by optimizing the shape of the parts. A computational analysis of the strength of the caps with bearing shafts was carried out, and areas with minimal strength and low resource were identified. The design was modified by changing the shape, adding radii of curves and smooth transitions. This made it possible to reduce the stress level, and therefore increase the strength and durability of the node," explained Andrey Okhotnikov, one of the developers.

In addition, the material has also been changed. Instead of high-strength cast iron, which is prone to brittleness at low temperatures, the engineers used alloy steel. As a result, the safety margin of the modified gearbox increased by 1.76 times, and the total life of the unit doubled.

Such gearboxes are used not only on tractors, but also on loaders and road construction equipment, which makes the development universal, the specialist added.

How improvements will help to harvest more crops

— Agricultural machinery in Russia operates in much tougher conditions than in Canada or Europe. This is due to large fields, difficult terrain, and extreme temperature changes. The new gearbox tolerates overloads better. This reduces the risks of downtime, which is critically important during sowing and harvesting campaigns, when every hour is more expensive than gold," emphasized Vladislav Pigenko.

According to him, the prototype tractor with reinforced units has already passed a full cycle of field tests. Now it is being prepared for accelerated tests at the test site in the Kursk region. At this stage, the tractor will be tested on specially created tracks with obstacles.

— The uninterrupted operation of machinery in agriculture is of paramount importance, since the timing of agricultural work is strictly limited. Disrupting the schedule even for one day can lead to crop loss and reduced economic efficiency. In this regard, manufacturers always pay special attention to the reliability of machines," explained the Head of the Department of Technical Operation of Technological Machines and Environmental Management Equipment at the Goryachkin Institute of Energy Mechanics of the Russian State Agricultural Academy named after K.A. Timiryazev.

According to the scientist, the presented development is really capable of increasing the life of the gearbox and increasing the reliability of this unit. However, in order to fully assess its significance, it is necessary to conduct a full cycle of tests and analyses.

— In agriculture, due to the pronounced seasonality and short deadlines for agricultural work, especially during sowing and harvesting campaigns, the trouble-free operation of machinery is of paramount importance. Disrupting them even for one day can lead to crop losses and, as a result, a decrease in the economic efficiency of production," explained Professor Alexey Apatenko, Head of the Department of Technical Service of Machinery and Equipment at the Goryachkin Institute of Energy Mechanics of the Russian State Agricultural Academy named after K.A. Timiryazev.

Therefore, the research of scientists is relevant and in demand, he added.

— The complexity of the work performed is that the part of the "driver" type (on which the satellites are placed — small gears) is the most responsible. It needs to be precisely manufactured, carefully assembled, sized correctly, and selected for suitable material and bearings. There are many places where you can make mistakes. Therefore, repeatability and stability of properties are important for such nodes," explained Alexey Karfidov, Head of the Department of Technological Equipment Engineering at NUST MISIS.

The expert added that in Soviet times, similar gearboxes in our country were designed and manufactured independently. Subsequently, this practice was lost, but today, in the context of import substitution, engineers are again engaged in complex developments, relying on the preserved theoretical and scientific base.