Pistonless rotary engine

A pistonless rotary engine is an internal combustion engine that does not use pistons in the way a reciprocating engine does, but instead uses one or more rotors, sometimes called rotary pistons. An example of a pistonless rotary engine is the Wankel engine.

The term rotary combustion engine has been suggested^{[by whom?]} as an alternative name for these engines^{[citation needed]} to distinguish them from early (generally up to the early 1920s) aircraft engines and motorcycle engines also known as rotary engines. However, both continue to be called rotary engines and only the context determines which type is meant. In particular, the only commercial producer of (pistonless) automobile rotary engines as of 2005^[update], Mazda, consistently refers to its Wankel engines as rotary engines.^{[citation needed]} O.S. Engines, which produces a Wankel model airplane engine, refer to it as a wankel rotary engine.^{[citation needed]}

[edit] Pistonless rotary engines

The basic concept of a (pistonless) rotary engine avoids the reciprocating motion of the piston with its inherent vibration and rotational-speed-related mechanical stress. As of 2006^[update] the Wankel engine is the only successful pistonless rotary engine, but many similar concepts have been proposed and are under various stages of development. Examples of rotary engines include:

Production stage

• The Wankel engine

Development stage

• The Liquidpiston engine
• The Sarich orbital engine
• The RKM engine (RotationsKolbenMaschinen)
• The Trochilic engine
• The Engineair engine
• The Rand cam engine
• The original Atkinson cycle engine

Conceptual stage

• The quasiturbine
• The Gerotor engine

[edit] External links

• Pistonless rotary engine at the Open Directory Project