Why does a tractor need triangular tracks?

The triangular track layout on construction and agricultural machinery is not uncommon today. There is careful engineering behind this relatively recent innovation.


The first to use such a design were the Americans - more precisely, the developers of the Caterpillar company. The idea turned out to be so successful that a significant part of the tracked equipment manufactured by the company received such a propulsion scheme.


Most often, "triangles" are found on bulldozers. But "everything starts better": today, for example, you can find combines with the same scheme. Even small municipal equipment also has non-standard propellers.

From the history

Construction and agricultural machinery has been improving for a number of years: not only the engine and transmission are being modernized, but also other important units and components. One of the "impets" for research into the optimal design of propellers was the experience of wars. Previously, the drive sprocket on tanks was mainly located at the back, which is logical: there is more load there. In Germany, they tried to move it to the front, but the system turned out to be unsuccessful. Engineers began to think further!

Advantages of the triangular design

The design was conceived to move the drive sprocket as far as possible from the surface with which the tracks come into contact. As a result, several important advantages were achieved - protection from dirt, self-cleaning, improved cross-country ability. When performing work, the tracks of the equipment are in constant contact with the ground, sand, stones, rock fragments, etc. And all this flies in a powerful stream to the rollers, bearings, sprockets. As a result, on bulldozers with a classic track design, the parts that come into contact with the ground have to be changed every couple of years.


And in the triangular scheme, the leading sprocket is on top and therefore is not so much exposed to dirt and impact of stones. The second point is to reduce the axial loads that occur when turning the equipment. Due to the non-standard location of the sprocket and gearbox, they "rest" (the lower wheels work) when the bulldozer maneuvers. The machine becomes more stable when driving on rough terrain, while the track does not slip.

Increased cross-country ability

The high-raised drive sprocket increases the ground clearance. This is especially important when performing quarry work, when there are a lot of rock debris under the bottom. High ground clearance helps the machine overcome obstacles, saving the transmission units located below. The triangular design also works as a "step", allowing the equipment to climb slopes with a steepness of up to 30 °. The sharp protrusions of the tracks create many contact points, which guarantees movement on loose soil and sand.


There is an empty space between the shoes in the triangle, where snow, dirt, stones are collected, which are then "automatically" thrown out during movement. The tracks clean themselves. To sum up, we can deduce the general plus: an increase in the service life of some units, mechanisms and parts, an increase in cross-country ability. Well, what about the minuses - is everything really so perfect? ​​Of course not.

Disadvantages

One of the advantages associated with reducing the possibility of slippage also has a negative point. The triangular track chain has a smaller angle of coverage, if compared with the classic scheme. This means: fewer teeth are engaged, which limits their service life. Of course, no one prevents them from increasing their number and height. But then the risk of slippage in the shoes increases. It is necessary to look for some kind of compromise.


Another disadvantage is the cost of the design. The track chain is longer, additional guide rollers are required. All this makes the system more expensive. The same can be said about repairs. Although, it will have to be carried out less often, compared to equipment with a traditional drive design.

Upgrades

It would seem that the triangular scheme created by Caterpillar is the most optimal for construction and agricultural machinery. But there is no limit to perfection: the Case IH company (today it is part of the American-Italian corporation CNN Industrial) presented to the public in 1996 tractor QUADTRAC, equipped with as many as four triangular tracks.


The company's engineers claim that the result of their efforts is the best option for agricultural machinery. It is this form of propellers and their number that ensure high productivity and efficiency, which cannot be achieved on a wheeled or two-track tractor. Among the advantages are complete copying of the relief, ideal weight distribution, no slippage. The disadvantages are the same as those voiced earlier - high cost, including maintenance. Case IH did not stop there and continued experiments. In particular, the MAGNUM ROWTRAC model was created, in which the wheels in front are adjacent to a triangular belt at the back.


The manufacturer claims that such a scheme combines the powerful traction qualities of a tracked tractor with the maneuverability of a wheeled one. And high cross-country ability here coexists with reduced fuel consumption. At the same time, it is possible to quickly adjust the distance between rows of plants: from 45 to 76 cm. Later, Case IH was one of the first to release a New Holland combine with wheels and triangular tracks.

What about other countries besides the USA?

The savvy Americans, having created a successful design, immediately patented it. For a long time, no one except Caterpillar used the design. However, the US did not expect that such a country as China would soon begin to develop by leaps and bounds. And they looked at American patents from their own point of view. For example, the Shantui company presented its bulldozer on triangular tracks – DH80-C6. Later, other models appeared from numerous manufacturers from the PRC.


In Europe (of course, having paid for the use of the American idea), the Liebherr company produced its own version of equipment on triangular tracks – the PR-776 bulldozer. The machine is successfully used in construction, and works in quarries.

Belarus and the Russian Federation

In 2018, the Minsk Tractor Works offered customers the MTZ 3525 with four, like the MAGNUM ROWTRAC, propellers on triangular tracks. Whether the Minsk residents bought the license from the Americans or not remains a "secret behind seven seals". Although, most likely, they agreed with their colleagues from China.


The tractor is positioned as universal. It can carry out pre-sowing preparation, prepare and harvest forage, grain.


And also be used as a vehicle. It is also possible to use MTZ 3525 in construction and industry.

Russian tractor "AGROMASH-RUSLAN"

Here there are not four, as the Belarusians have, but two propellers: one on each side. The machine is manufactured by PAO Promtractor. The equipment, which has the sixth traction class, is equipped with an American diesel engine Cummins QSM11.


"AGROMASH-RUSLAN" is designed to perform a wide variety of agricultural work on medium and heavy soils.

Results

The triangular design invented by Caterpillar engineers is certainly a real find for tracked tractors. And the use of the design by manufacturers in different countries, including Russia, serves as proof of this. And it is unlikely that the American patent will be able to hold back the development of progress.