Mercedes-Benz farm tractor OE
| Mercedes Benz | |
|---|---|
Diesel tractor OE (1928) in the Mercedes-Benz Museum |
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| Agricultural tractor OE | |
| Manufacturer: | Daimler Benz |
| Sales designation: | Agricultural tractor OE |
| Production period: | 1928-1931 |
| Engines: | Single cylinder diesel engine |
| Standard tires: | Steel, 1.30 m in diameter |
| Top speed: | 6.2-15 km / h |
| Empty weight: | 2560-3200 kg |
| Previous model: | Four-wheel diesel tractor BK |
| Successor: | none |
The Mercedes-Benz farm tractor OE was a tractor from the Mercedes-Benz brand that Daimler-Benz presented at the International Motor Show (IAA) in Berlin in spring 1928 . It was offered from May of the same year. With a whole series of new technical details, it made agricultural work easier.
History of origin
As early as 1902, the Daimler-Motoren-Gesellschaft (DMG) in Berlin received the first prize from the German Agricultural Society for its universal locomobile . Of course, full suitability for the fields was only achieved with the “Daimler Motorized Plow” introduced in 1913: the 6.6-ton articulated plow was not far removed from the principle of the tractor with plow trailer, as it was to become generally accepted in the 1920s. In 1921 DMG finally presented such a “plow tractor”, a good five meters long and weighing four tons.
After the merger of Benz & Cie. and the Daimler-Motoren-Gesellschaft zur Daimler-Benz AG in 1926, everything spoke in favor of the former competitor's model. The decisive factor was the diesel engine that Carl Benz had installed in a three-wheel tractor as early as 1922. Benz developed this tractor with a single, roller-like drive wheel with a diameter of 1.40 meters together with the Munich engine and tractor manufacturer Sendling immediately after the First World War , and exhibited and sold it for the first time at the agricultural exhibition in Königsberg in 1922. The trial with the crude oil engine was initially aimed more at practical testing of the pre-chamber diesel, a year before it was first installed in a truck. But the diesel tractor was also a great success.
Two more units followed before the diesel-powered Benz Sendling single-wheel tractor S6 went into series production the following year. The first hundred had been sold by 1925, and another 200 copies followed. In total, Benz-Sendling was able to sell 1,188 units of the three-wheel draft horse by the early 1930s.
The main reason for the single-wheel plow - or the very similar plow tractor from Daimler with two rear wheels arranged close together - was that a differential gear could be saved in this way . It soon became apparent, however, that this advantage came at the price of an increased risk of tipping over. Benz-Sendling developed the four-wheel diesel tractor BK as early as 1923, which was also available in a road version with solid rubber tires. It was the direct forerunner of the OE.
Benz-Sendling had last had its tractors manufactured by Komnick in East Prussia: The designation “BK” indicates that it is a Benz diesel engine on a Komnick chassis. The OE, on the other hand, was to be manufactured in Stuttgart-Untertürkheim .
The global economic crisis set clear limits to customers' purchasing power. The Daimler-Benz diesel engine promised low operating costs and thus to be successful. This prompted the company to send the OE into the field against the domestic tractor manufacturers in 1928. However, the hoped-for success did not materialize - as early as 1931 and after only around 100 units had been built, production of the tractor was stopped.
technology
The tractor had a weight of approx. 2560 kg with an axle load distribution of 60% at the rear and 40% at the front. The output of the single-cylinder diesel engine was 24, later 26 PSm at 800 rpm. The engine was installed horizontally and transmitted its power to a three-speed gearbox via a clutch built into the left flywheel. In addition to the engine, the crank gearbox also accommodated the gearbox, power transmission and final drive. The engine worked according to the pre-chamber method. A decompression device made it easier to start the diesel engine, which was started with the help of an ignition cartridge. The engine had a speed controller that was driven by the camshaft .
The rear wheels of the Mercedes-Benz diesel tractor were 1.30 meters in diameter. The flat iron wheels were fitted with 14 diagonally arranged angular grippers. A widening could be made for bog soils. As a road tractor, the OE was delivered with elastic or pneumatic tires, with double tires at the rear. The length was 2.64 meters. Since the curve radius was only four meters, a differential gear was necessary.
The front view of the OE essentially consisted of four parts: the single-cylinder engine attached to the front of the gearbox housing, a flat, rectangular container above it that contained the cooling water and the fuel tank, as well as an air filter towering high on the right-hand side and the exhaust pipe on the left. The low heat generation of the diesel engine allowed the manufacturer to use evaporative cooling instead of the usual, frost-prone circulation cooling. Of course , Daimler-Benz also offered circulation cooling for export to warmer countries .
The close connection of motor and gear in a single, torsion-resistant housing benefited the efficient and permanent pressure circulation lubrication. Compared to a chain, pinion or worm drive, the direct power transmission from the gearbox to the rear wheels by means of spur gears also proved to be very durable.
The tractor reached 3.2 km / h in first gear, 4.5 km / h in second and 6.2 km / h in third.
Two large, easily removable maintenance flaps provided easy access to the dust-tight gear housing if necessary. Changing the cylinder liner, made from a special cast iron alloy with chromium and nickel additives, was just as easy if it was knocked out after many hours of work.
application areas
The major disadvantage of earlier motorized plows was that, due to the fixed connection between the plow and the drive, they were only suitable for the heavy work of plowing. The universal tractor OE could do more: A PTO drive got mowing machines , potato harvesters, beet lifters and sorters going. In addition, a belt pulley could be installed to drive stationary machines, the speed of which could be regulated between 300 and 800 revolutions per minute. In this way, the tractor also served as a drive for pumps, circular saws , threshing and chopping machines, grist mills or dynamos .
With deep plowing he worked six to eight Prussian acres (approx. 1.5-2 hectares) in a ten-hour working day , with seed plowing with a two- to three-furrow plow it was ten to twelve acres, while with peeling with a five-furrow plow he worked 20 to 25 acres reached. He tilled and harrowed up to 40 acres a day .
Prices and operating costs
When it was introduced, the tractor cost 6,600 Reichsmarks - but Daimler-Benz later lowered the price to 5,900 RM. In relation to the year 1928, these sums, adjusted for purchasing power, correspond in today's currency to approx.
The farmer had to calculate between 20 pfennigs for cultivating and harrowing and 80 to 90 pfennigs for deep plowing for one morning's cultivation of arable land. In addition to the much cheaper price of diesel oil, consumption was 30 percent lower than that of a gasoline engine, so that even with an annual load of 1200 operating hours, savings of 1500 RM resulted.
Road tractor version
In addition to the farm tractor, there was also a road tractor version. In this case, all-metal wheels with solid rubber or pneumatic tires took the place of the gripper wheels. The transmission was given a different gear ratio by changing two wheels. The road tractor managed 10.6 or 12.3, later up to 15 kilometers per hour, depending on the trailer load. Here the customer was free to choose depending on the individual requirements: Normally the tractor pulled 15 tons in third gear on a level road, and the overall gear ratio could be changed accordingly for larger loads or gradients.
The air filter on the road tractor was simpler. A belt pulley for driving stationary machines was available at an additional cost, as was a cable winch in the rear, a hood with side weather protection and petroleum, carbide or electric lamps. Thanks to the maintenance flaps in the transmission housing, the tractor could also be easily converted into a road vehicle at a later date: it was enough to change the four wheels and two gears of the transmission. Later, Daimler-Benz offered the tractor under the name "Combination tractor" with a double wheel set and gear wheels for changing from field to road operation.
At 3.2 tonnes, the road version weighed significantly more than the field version, especially due to the tires.
literature
- Werner Schmeing, Hans-Jürgen Wischhof: Tractors from Daimler AG , DLG Verlag, Frankfurt am Main 2009, ISBN 978-3-7690-0733-6 , p. 168ff.
- Wolfgang H. Gebhardt: German tractors since 1907 . MotorBuch-Verlag Spezial, 1st edition 2006, ISBN 978-3-613-02620-9
- Automobil und Motorrad Chronik, issue 12/77, pp. 11, 12 and 32. Author: Jens Ostermann
Web links
Individual evidence
- ^ Advertisement by Mercedes-Benz Automobil-Gesellschaft mbH , Allgemeine Automobil-Zeitung, Vienna, March 1, 1930, Austrian National Library.
- ↑ The figures were based on the template: Inflation determined, rounded to 100 EUR and apply to the previous January.