The Selbstfahrer is the first self-propelled combine harvester by Claas. In total, 19.465 units^[1] were produced from 1952 to 1963. The German name Selbstfahrer literally means Self-propeller and in the German agricultural language, it refers to a combine harvester or agricultural machine that can propel itself. Initially, the name of the Selbstfahrer was Hercules; due to an already registered trademark with the name Hercules, the combine harvester was renamed SF for Selbstfahrer in 1953.^[2] In contemporary brochures, the Selbstfahrer is called Claas Selbstfahrer Type S.F.55. It was targeted at agricultural contractors and large farms in Europe.^[3] In 1961, the Selbstfahrer was succeeded by the Matador.^[2] However, it was kept in production until 1963.

Technical description

The Selbstfahrer is a self-propelled straw walker combine harvester. For the German market, the Selbstfahrer was offered with a 2600 mm cutter bar, in other countries, 3000 mm and 3600 mm cutter bars were offered as well. The cutter bars – designed for harvesting bent fruit – and the reel are adjustable vertically with a hydraulic system. The cutter bar is replaceable with a pickup-reel. The Selbstfahrer is usable as a stationary threshing machine as well.

The threshing drum with a width of 1250 mm and a diameter of 450 mm has six rasp bars, its rotational speed is infinitely adjustable between 650 min⁻¹ and 1400 min⁻¹. The distance between the threshing drum and concave is finely adjustable. Four straw walkers with an overall width of 1250 mm and a total length of 2400 mm separate the remaining grain from the straw. The grain is cleaned twice with sieves measuring 920 mm × 1070 mm. An elevator transports the cleaned grain to a sorting cylinder on the roof. It sorts three quality grades of grain. For some fruit types, special sorting sieves were offered.

The sorted grain is sacked on the roof with a sack-filling machine, the sacks can either be put on the field or loaded over onto a trailer with a chute. The Selbstfahrer′s roof can store up to ¾ – 1 tonne of grain (15–20 sacks, 50 kg each). An unloading pipe was also available for the Selbstfahrer, grain can be unloaded with it while harvesting. A grain tank was offered by Claas too. Per hour, the Selbstfahrer can harvest up to 4 t of grain. The Selbstfahrer was offered with or without a straw baler.

Like later Claas combine harvesters, the Selbstfahrer has a three-speed-gearbox with an additional reverse gear. It also has a hydraulically controlled continuously variable transmission (CVT) that uses a belt to transfer the torque. The driving speed is adjustable within the three gears using the CVT. At maximum engine rotational speed, the top speed is 19 km/h in the third gear; the minimum speed is close to 0 km/h in the first gear. Only the front wheels are propelled, the tyres are filled with air.

The standard engine offered in the Selbstfahrer is a straight-six otto engine producing 41 kW. It is mounted on the roof to prevent the air intake from drawing in the threshing dust.^[4] The torque is transmitted to the gearbox with a single disc dry clutch. A straight-four diesel engine was offered as a factory option. At least two engine models were used: The Claas LD 40, a 4.7 L diesel and the Perkins 4.270, a 4.4 L diesel. Both engines produce 44 kW.

Sources

• Claas-Selbstfahrer brochure, 1955
• Claas Mähdrescher S.F., 1956

Bibliography

• Jürgen Hummel; Alexander Oertle; Jan Sternberg; Peter Felser, Mähdrescher: Geschichte und Technik (in German), Kempten: wk&f Kommunikation, p. 39, ISBN 978-3-8988-0417-2

References