Motorenfabrik Oberursel
Motorenfabrik Oberursel A.G. was a German manufacturer of automobile,
The factory in Oberursel is claimed to be the oldest surviving aircraft engine factory in the world.[1]
Early years
The company had its origins in 1891, when Willy Seck invented a new gasoline fuel injection system and produced a small one-cylinder stationary engine of about 4 hp, which he called the Gnom.[2] The following year he founded Willy Seck & Co. to sell the design, which became famous around the world.[1] The engine was improved to achieve more power, but in 1897 the shareholders refused to allow Seck to develop a Gnom-powered car and he left the company. The company was reorganized as Motorenfabrik Oberursel the next year, and by 1900 had built 2,000 engines.
The same year the company granted a license to the Seguin brothers in Lyon to produce the Gnom in France. Sold under the French name Gnome, the engine became so successful that they renamed their company to the same name. In 1908 they developed a rotary version of the basic Gnome system as the Gnome Omega aircraft engine, and from there a series of larger versions of the same basic design. The new Gnome engines were wildly successful, powering many of the early record breaking aircraft.
In 1913 Motorenfabrik Oberursel took out a license on the French Gnome engine design and the similar Le Rhône 9C. They produced both, the Gnomes as the U-series, and the Le Rhônes as the UR-series.
The
World War I
When World War I started the following year the Oberursel U.I of 100 hp, a clone of the Gnome Delta 100 hp (75 kW) rotary, had the best power-to-weight ratio of any German engine. It went on to power most of the early German fighters, such as the Fokker and Pfalz E-series monoplanes.
Oberursel also built a copy of Gnome's 14-cylinder Double Lambda two-row rotary. This 160 hp (120 kW) engine, designated U.III in Germany, was difficult to build and quickly wore out in service. It was used on the Fokker E.IV and D.III designs.
The 110 hp
By 1917, the UR.II had been rendered obsolete by its relatively low power and poor performance at altitude. An 11-cylinder development, the UR.III, was not used operationally. Indeed, by 1918, rotary engines had largely fallen from favor with the Idflieg and with pilots. The lack of castor oil and the poor quality of the mineral oil substitute "Voltol" severely reduced engine life and reliability. Nevertheless, in the summer of 1918, the UR.II was installed in the Fokker D.VIII. The light weight and aerodynamic cleanliness of the D.VIII allowed it to achieve excellent performance even with the outdated UR.II.
After the war the company was purchased in 1921 by
World War II
In 1940 during World War II all diesel research was relocated to Oberursel, where Dr. Ing. Adolf Schnürle led the development of much larger and more advanced engines for aircraft use. This led to the
Post-World War II
For a short period in 1946 the factories were used as a tanks and trucks repair depot by the US army.
In 1956 the factories were returned to Klöckner-Humboldt-Deutz, and from then on have been used primarily for gas turbine development and production. For the next twenty years they produced a variety of designs, typically under license from other companies. In 1980 they were renamed KHD Luftfahrttechnik GmbH.
In 1990 the company was sold to what was then
Engines
- Oberursel U.0
- licensed Gnome 7 Lambda, 68/80 hp (51/59 kW) seven cylinder rotary.
- Oberursel U.I
- 100 hp (75 kW), nine cylinder, and total displacement to 16.3 litres (990 cu in) 124 mm × 150 mm (4.9 in × 5.9 in)[3]::
- Oberursel U.III
- Gnome Double Lambda 14-cylinder, two-row rotary engine copy. 160 hp (120 kW).
- Oberursel Ur.II
- Clone of the Le Rhone 9J110 hp (82 kW) nine cylinder rotary.
- Oberursel Ur.III
- 11-cylinder development of the Ur.II. 145 hp (108 kW) and total displacement to 18.42 litres (1,124 cu in)
- Oberursel 200 hp 18-cyl rotary
- 124 mm × 150 mm (4.9 in × 5.9 in)[3]
- Oberursel 240 hp V-8[3]
References
- ^ a b "Press release on the occasion of the company's 110th anniversary" (PDF). Rolls-Royce Deutschland Ltd & Co KG. 2002. Archived from the original (PDF) on 19 July 2004. Retrieved 18 July 2008.
- ^ "Motorenfabrik Oberursel, Yesterday and Today" (PDF). Rolls-Royce Deutschland Ltd & Co KG. 2008. Archived from the original (PDF) on 19 March 2012. Retrieved 18 August 2011.
- ^ a b c Angle, Glenn D. (1921). Airplane Engine Encyclopedia. Dayton, Ohio: THE OTTERBEIN PRESS.