Mercedes D III
The Mercedes D III was an aircraft engine of the Daimler -Motoren-Gesellschaft. The six-cylinder in-line engine with a continuous output of 120 kW ( 160 hp ) and liquid cooling came from 1915 in various machines of the Air Force of the German Army for installation. Due to the front experiences took place in the second half of 1916 without power increase, the revision to the D IIIa, from the to 1918 a total of 12,000 units were shipped. The Mercedes D IIIa, making it the most-produced German aircraft engine of World War II.
Construction
The crankcase is split horizontally. The single overhead camshaft driven by a vertical shaft. The hanging valves are actuated by roller rocker arms. The cylinders are arranged separately and have separate water jackets welded from sheet steel. The intake air is supplied to the crankcase through the carburetor (s). The coolant is circulated by a pump. The two spark plugs per cylinder ( dual ignition ) are driven by two Bosch magnetos tempering. These bring even during cranking the armature to a high speed to produce sufficiently strong spark.
While maintaining the bore and stroke arose from the D III by adding two more cylinders of the eight-cylinder engine Mercedes D IV who underwent acceptance testing in late 1915. The engine with 19.7 liters displacement and an output of 160 kW ( 220 hp ) was the first German series aircraft engine with a propeller gearbox, but was also shipped without this. Due to the large overall size problems arose both in the housing stiffness and strength of the vibration of the crankshaft and the production was discontinued after the delivery of 429 pieces.
Therefore, a more powerful six -cylinder engine was now, again on the basis of the D III constructed. By increasing the stroke to 40 mm to 180 mm and the use of four- valve technology, the Mercedes D IVa was 21.7 liters and an output of 194 kW ( 260 hp ), which passed the acceptance test in June 1916.
Use
The Mercedes D-III/D-IIIa-Motoren were installed in machines almost all manufacturers:
- AEG C.I, C.IV
- Albatros C. III, D I, D.II, D.III, D.V
- Fokker D.IV, D.VII, D.VIII
- Friedrichshafen FF 33
- Halberstadt CL.II
- Hanover CL.III
- Junkers J 2, CL.I
- Pfalz D.III
- Roland D.II, D.VI
- Rumpler C.I