Revolution Rotary Engines Inc.

Development of the Wankel Engine

Initiated by a gas turbine project of BBC company, the roots of Felix Wankel’s studies about rotary piston engines go back to 1926. Felix Wankel (1902-1988) wrote in his diary:

“The big difference between the attempt (BBC) and my own is, that I do not want to replace the steam- or water jet by a jet of burning hot gas but I want to transfer the cycle, which is currently used in reciprocating piston engines, into a rotary motion. Intake, compression, ignition and exhaust shall happen in the conventional manner, because I think it is the optimum for the ignition characteristics of gasoline. My only task is to develop the mechanical design and to manage the work of the gas with a rotating instead of a reciprocating piston.”

But it took many years until the first prototype engine DKM54, jointly developed with NSU, ran successfully for the first time in February 1957. NSU later followed a different approach, preferring the less complex design of the rotary piston engine. The KKM57, called the prototype engine, achieved the same performance during tests in mid-1959, at identical chamber volume, as the DKM54. Felix Wankel had hardly been involved in the development of the rotary engines for the NSU Spider and Ro80. He invested a lot of effort in the basic research and development of sealing systems apart from the development of engines and superchargers, as well as the completion of the book “Einteilung der Rotationskolbenmaschine” (“Classification of the Rotary Piston Engines”). Felix Wankel continued working on his lifework until he died in October 1988.

The German company Wankel GmbH was founded in Munich in 1957 to market the rotary engine. A contract signed with NSU defined the joint utilization of the invention as well as the shares between NSU and Wankel GmbH for future royalty revenues.

The first license agreement was signed in 1958 with Curtiss Wright Corp.. Numerous additional license agreements followed until 1971. Nearly all of the well-known engine companies can be found on the list of those who seriously considered the technology of the rotary piston engine during this period.
Just at the peak of worldwide Wankel activities in 1971, Wankel GmbH was sold to the British enterprise Lonrho. Apart from Wankel GmbH, which became accountable for all future contractual issues, the Wankel Research and Development GmbH (Wankel R&D GmbH) was founded to manage all development activities under the guidance of Dankwart Eiermann and his development team. In 1982 Wankel R&D GmbH, which had been engaged in new rotary piston development projects in addition to having provided engineering support to the licensees worldwide, moved from the old Felix Wankel institute to its new well-equipped facility located at Lindau, close to Lake Constance. They developed compressors for air-conditioning systems and superchargers, which went into series production at a licensee in Japan. In addition, a new series of rotary engines (LCR) burning gasoline was developed to power light aircraft and other types of sport craft. A derivative was the LOCR engine, which had been equipped with a high pressure direct injection system and successfully demonstrated its multi-fuel capability in a NATO test cycle.

In 1992 Lonrho withdrew from this enterprise. This move was followed by a management buy-out by Dankwart Eiermann, who brought the company into the newly formed Wankel Rotary GmbH.
The managing director and chief engineer Dankwart Eiermann, as well as a number of other experts from the original staff of Felix Wankel, enabled the integration and acquisition of the full material heritage of Felix Wankel into Wankel SuperTech GmbH, founded in 2003.

In the automotive industry MAZDA was one of the first companies that applied for a Wankel license. MAZDA is also the only company to still continue the development of rotary engines and to operate a highly sophisticated facility for high volume series production. In Japan, MAZDA has produced more than two million cars equipped with rotary engines having their origin in Germany and has sold them worldwide with economic success. MAZDA has been the first and only automotive company which became the winner in 1991 at the 24 hours of Le Mans, one of the most challenging long-distance races, using a four-rotor-rotary-engine. This and other successful engagements in racing sports led to the assessment of MAZDA as a high technology company.

Wankel

A - Rotor
B - Eccentric Shaft