Siemens & Halske Sh.III

from Wikipedia, the free encyclopedia
Sh.III in the Technisches Museum Wien

The Sh.III from the German manufacturer Siemens & Halske was an air-cooled rotary engine with 11 cylinders that was developed during the First World War .

history

The development of rotary engines at Siemens & Halske began 1912 with the ultimately unsuccessful Sh.I . However, with the Sh.I , Siemens showed that a counter-rotating motor was practicable as a rotary motor. The Sh.II was again unsuccessful. From autumn 1916 onwards, the focus was on the Sh.IIIa , which was designed as an altitude motor with over-dimensioning and over-compression , which compared to the original type had more displacement and was more powerful. The project manager was Franz Dinslage , the project goal was a counter-rotating rotary engine with 160 hp at 900 min −1 propeller speed.

After a comparison flight in the late summer of 1917, Siemens and the licensee Rhemag were given a production order for 2500 pieces. Production began in February 1918. The troop trials showed quality problems in the engines manufactured by Siemens, in particular piston damage after 8 to 10 hours of running, so that the engines were then taken back from the front in May 1918, while the engines manufactured by Rhemag met the requirements better enough. Siemens improved the type and finally achieved a short-term performance of 200 hp on the ground with the type called Sh.IIIa . In comparative flights towards the end of the war, the Sh.IIIa proved to be equivalent to the Oberursel UR IIIa and the Goebel Goe III .

construction

animation

In this rotary engine, the cylinders with the propeller rotated at 900 min −1 , while the crankshaft rotated in the opposite direction at the same speed, which led to an effective engine speed (crankshaft revolutions compared to the engine housing) of 1,800 min −1 . This resulted in a very good efficiency of the propeller and a low gyroscopic effect for rotary engines .

use

Technical specifications

Parameter Data of the Sh.IIIa
design type 11-cylinder rotary engine, two valves per cylinder
drilling 124 mm
Hub 140 mm
Displacement 18.6 l
power 240  hp (180  kW ) at 1800 min -1 (crankshaft speed)
Dry matter 194 kg

See also

literature

  • Kyrill von Gersdorff, Kurt Grasmann: aircraft engines and jet engines . Bernard & Graefe Verlag, 1981, ISBN 3-7637-5272-2 .

Web links

Commons : Siemens-Halske Sh.III  - collection of pictures, videos and audio files