Felix Wankel

Felix Wankel

Felix Wankel

German engineer Felix Wankel is best known for his invention of the Wankel engine. The Wankel engine is a gasoline-powered engine that is more powerful than the engines usually used in automobiles.

Felix Wankel (1902-1988), German engineer, best known for inventing the Wankel engine. Sometimes called the Wankel rotary engine, the Wankel engine uses a turning rotor inside a housing instead of pistons to provide power. It is more powerful and easier to maintain than a traditional internal-combustion engine of the same size.

Born the son of a forestry official in the Black Forest of Germany, Wankel never pursued a higher education. He did, however, show great skills in engineering and mathematics as well as an intense interest in vehicle propulsion. He began developing an engine around 1927, having in mind a novel design for gasoline-powered, internal-combustion engines. He received his first patent in 1929, for plans he made for a rotary engine.

The main parts of Wankel’s engine are a roughly cylindrical chamber and a triangular rotor with rounded edges. The chamber’s cross-section is actually an ellipse, or an elongated circle, instead of a perfect circle. The chamber has two openings on one of the ellipse’s long sides. One allows fuel to flow into the chamber and the other allows exhaust to escape. A spark plug, a device that uses a strong electric current to produce a spark between two electrodes, is centered on the other long side of the chamber. The rotor’s corners fit snugly against the sides of the chamber, effectively dividing the chamber into three parts. As the rotor turns, it draws in fuel in one chamber, compresses the fuel until the spark plug ignites the fuel and burns it in the second chamber, and allows the byproducts of combustion to escape from the third chamber. The burning, expanding fuel gases forces the rotor to turn. The rotor is usually connected directly to a driveshaft. The engine’s simplicity makes it lighter and more powerful than a traditional Otto-cycle internal-combustion engine. However, it uses fuel faster than an equivalent Otto-cycle engine, and it releases more exhaust.

Wankel joined the National Socialist German Workers' Party (Nationalsozialistische Deutsche Arbeiterpartei, or NSDAP) in the 1920s but left the party in 1932, before the Nazis came to power. Conflicts with local Nazi officials led to his arrest and imprisonment for several months in 1933. After his release, he worked for the German Aeronautical Research Establishment, where he refined his rotary piston engine design. When the Allies invaded Germany in 1945 during the final stage of World War II, Wankel was captured and held as a prisoner of war in France until 1946.

After his release, it took Wankel several years to rebuild a research program. He gained the support of the German motorcycle manufacturer Neckarsulm Strickmaschinen Union (Neckarsulm Knitting-machine Union, or NSU) in 1951. Wankel finally produced a fully functional prototype of a rotary engine in 1956. In 1957 he formed a company called Wankel GmbH to license the design of his engine, and other companies paid Wankel GmbH for the right to used the rotary engine. Wankel sold his company in 1971. The company now builds rotary engines, used mostly for aircraft and go-carts. Wankel created Technische Entwicklungsstelle (Center for Technical Advancement, or TES) in 1976 as a research institute. German industrial company Daimler-Benz bought TES in 1986.

Major companies in several countries commercially developed the Wankel engine. The German manufacturer NSU used the engine in boats and several models of cars. The NSU used the engine in its R0 80 luxury sedan in the 1960s, but it showed problems of high fuel consumption and exhaust pollution. The Japanese automobile maker Mazda used it in sports cars, most notably the RX-7, from the 1970s to the 1990s. The Wankel engine has also been used by high-performance motorcycle makers.

Wider use of the Wankel engine remains possible if the high fuel consumption and exhaust pollution problems can be resolved. The Wankel engine is still the most radical innovation in hydrocarbon internal combustion engines since the familiar Otto-cycle internal- combustion engine was developed in the 19th century. Tests in the 1990s showed that the rotary engine burns liquid hydrogen well. Hydrogen exhaust would be harmless, unlike the exhaust from petroleum-based fuel. Liquid hydrogen is difficult and expensive to produce and store, but if it ever becomes a common fuel, the Wankel engine could become much more practical.