Rotary Engine Seals
Novel sealing solutions for the rotor and its housing.
Extended service intervals Enhanced performance and reliability Improved fuel economy
Many advantages and many applications The rotary engine or Wankel engine was invented by German engineer Felix Wankel. Rotary engines are a type of internal combustion engine in which a rotor’s eccentric motion is used, rather than a reciprocating piston, to compresses the combustion gases and convert the engine’s work into motion. The rotary engine design has a number of advantages and is renowned for its smooth running, compactness and high power-to-weight ratio. As a result, the engines are used in a wide variety of applications from chainsaws to automobiles. Particular areas of interest are portable emergency power generation; Unmanned Aerial Vehicles (UAVs) and range extender engines for electric vehicles. Sealing problems As well as being renowned for their advantages, rotary engines also have a reputation for sealing problems. Geometric considerations mean that sealing a rotary engine is inherently more difficult than sealing a piston engine. Although replacement seal parts are inexpensive, the time and cost involved in dismantling an engine to change worn or failed seals is less so. Sealing problems which lead to reliability or shortened service intervals restrict the use of rotary engines in a number of fields. A New Approach Researchers at the University of Oxford have brought their know-how from the demanding world of gas turbines to the problem of sealing rotary engines. They have designed novel sealing solutions which deliver increased compliance between the rotor and its housing. The result is improved sealing and reduced wear providing a number of benefits: Extended service intervals Enhanced performance and reliability Improved fuel economy These advantages are of relevance to all the applications driving the uptake of rotary engines today. Current Status Initial concept design has been completed with funding for a proof of concept programme now in place. The underlying technology is the subject of a UK patent application. Companies designing and manufacturing rotary engines or sealing systems will have an interest in this project.