Dr. Wankel, “the father of the rotary engine“, was born August 13, 1902 in Lahr, Germany. He was the only child of Rudolf Wankel (1867-1914), a senior forestry official who was killed by shrapnel in World War I as an Oberleutnant.
Although his family’s poverty (due in part to his mother’s status as a widow) meant he had to go to work and could not apprentice or follow further full-time studies, he gained academic recognition within his own time. His first job was in 1921 printing, stocking, and apprenticing in sales for a scientific book publisher in Heidelberg. The German Depression caused him to be laid off in 1924. Because he devoted his energy to tinkering he was able to open his own workshop and that same year conceived the idea of a rotary engine (at only 22!).
Wankel’s first attempt to obtain a patent was in 1926 for a “grease turbine”, but it was predated by an Enke design from 1886. In 1927 he made drawings of the shape of the “drehkolbenmaschine without uneven moved sections”, or rotary engine, and of sealing parts. He received his first patent in 1929 (DRP 507 584) and would continue to be issued patents for six decades. In 1933 he applied for a patent for a DKM engine, which he received in 1936.
In the following years, Wankel mostly made his way by ingenious work on rotary valves and sealing technology for Lilienthal, BMW, DVL, Junker, and Daimler-Benz. During this time he developed various DKM prototypes along with rotary pumps and compressors. When the French army invaded in 1945, his workshops and research were dismantled (destroyed) by the French and he was imprisoned until 1946.
During the Allied occupation, Felix Wankel began secretly writing his book on the organization of rotary engines. He was able to rebuild a research operation by 1951 when he interested NSU in development. This lead to collaboration with Walter Froede, head of the motorcycle racing program, who would ultimately make the decision to adopt the KKM type.
The first truly functional Wankel rotary engine was a DKM type constructed in February 1957. By May a prototype was able to run for two hours and produce 21 bhp. The first KKM engine ran on July 7, 1958.
Many people had proposed rotary engine designs, but none had pursued it for as long or as relentlessly as Felix Wankel. He and NSU rigorously investigated all technical aspects such as sealing, spark plug positioning, port timing, cooling, lubrication, combustion, materials, and manufacturing tolerances. Thus where all others had failed, he and NSU were able to succeed by combining imaginative invention and scientific engineering.
A Nazi Engine?
While Hitler’s Germany was reviled for atrocities against humanity it was and is admired by some for technological advancement. The Volkswagen Beetle began as a project for Nazi Germany (Volkswagen literally meaning ‘People’s Car)by Dr. Porsche, later of sports car design fame. Rockets that pummeled England were among the first of their kind and led to the development of the technology that brought Humankind to the moon. But are alligations that Felix Wankel developed the rotary engine for the Nazis true?
Like many middle class Germans of his time, ruined by the runaway inflation of the 1920’s, Wankel was attracted by the political and economic philosophies of national socialism. As a young man he was a member of the Hitler Youth (where he met his wife, Emmy Kirn) and then a member of the NSDAP party. He resigned from the Nazi Party 1932 which was the right idea, but the wrong time to do so; in 1933 the Nazis came into power. This lead to conflict because Wankel had exposed some corruption by the provincial chief (Gauleiter) Wagner. He was arrested and held in prison by the Nazis for some months in Lahr until an industrialist and an engineer intervened on his behalf.
His resignation prior to the Nazis rise to power, and subsequent imprisonment on political grounds, combined with the fact that he began patenting rotary designs in the mid 1920’s before joining the party, all seem to dispell the Nazi taint on Wankel’s brilliant design.