Mercedes D III
The Mercedes D III was an aircraft engine from Daimler-Motoren-Gesellschaft . The six-cylinder in - line engine with a continuous output of 120 kW (160 PS) and liquid cooling was installed in various aircraft of the German Army from 1915 . Based on experiences at the front, the revision to the D IIIa took place in the second half of 1916 without an increase in output, of which a total of 12,000 units had been delivered by 1918. The Mercedes D IIIa is the most built German aircraft engine of the First World War . The Mercedes D II is known as the forerunner of this engine .
construction
The crankcase is divided horizontally. The single overhead camshaft is driven by a vertical shaft. The hanging valves are operated by roller rocker arms. The cylinders are arranged individually and have separate cooling water jackets made of welded sheet steel. The intake air is supplied to the carburetors through the crankcase . The coolant is circulated with a pump. The two spark plugs per cylinder ( dual ignition ) are two Bosch - Special Event magnetos controlled. These bring the magnet armature to a high speed while it is being cranked in order to generate sufficiently strong ignition sparks.
Mercedes D IV / D IVa
While maintaining the bore and stroke, the D III was converted into the eight-cylinder Mercedes D IV by adding two more cylinders , which passed the acceptance test at the end of 1915. The engine with a displacement of 19.7 liters and an output of 160 kW (220 hp) was the first German series aircraft engine with a propeller gear , but was also delivered without it. Due to the large overall length, problems arose in terms of both the housing rigidity and the vibration resistance of the crankshaft, and production was discontinued after 429 units were delivered.
Therefore, a more powerful six-cylinder engine has now been designed, again based on the D III. By enlarging the bore from 140 to 160 mm and the stroke from 160 mm to 180 mm as well as the use of four-valve technology , the Mercedes D IVa was created with a displacement of 21.7 liters and an output of 194 kW (260 hp), which was launched in June 1916 Passed the acceptance test.
use
The Mercedes D-III / D-IIIa engines were installed in machines from almost all manufacturers:
- AEG CI , C.IV
- Albatros C.III , DI , D.II , D.III , DV
- Fokker D.IV , D.VII
- Friedrichshafen FF 33
- Halberstadt CL.II
- Hanover CL.III
- Junkers J 2 , J 3 , CL.I
- Palatinate D.III
- Roland C.II , D.II , D.VI
- Rumpler CI
- Sablatnig SF 1
- Sablatnig SF 2
Technical specifications
| Parameters | Data |
|---|---|
| Manufacturer | Daimler Motor Company |
| Construction year | 1916-1918 |
| design type | 6-cylinder in-line engine |
| Displacement (bore × stroke) | 14.8 l (140 mm × 160 mm) |
| compression | 4.6: 1 |
| Dry matter | 268 kg |
| Starting power | 130 kW (180 hp) at 1450 min -1 |
| Continuous output | 120 kW (160 hp) at 1400 min -1 |
See also
literature
- Kyrill von Gersdorff, Kurt Grasmann: Flugmotoren und Strahltriebwerke , Bernard & Graefe Verlag 1981, ISBN 3-7637-5272-2 , p. 28
Web links
- Mercedes aircraft engine D III. Daimler AG, accessed on April 9, 2015 : "More than 12,000 units produced make the D III with the further developed D III a the most popular aircraft engine of the First World War."
Individual evidence
- ↑ The 260 HP Mercedes Aero Engine. (PDF) In: Flight, January 3, 1918. Flight, January 3, 1918, pp. 9–13 , accessed on May 12, 2019 (English).