Orbital engine
Categories: Proposed engine designs
The Sarich orbital engine is a type of internal combustion engine, featuring rotary rather than reciprocating motion of its internal parts. It differs from the conceptually similar Wankel engine by using a shaped rotor that rolls around the interior of the engine, rather than having a trilobular rotor that spins "in place".
Contents |
Overview
The advantage is that there is no high-speed contact area with the engine walls, unlike in the Wankel where edge wear is an ongoing engineering problem. However, the combustion chambers are divided by blades which do have contact with both the walls and rotor.
The orbital engine was invented in 1972 by Ralph Sarich, an engineer from Perth, Australia, who worked on the concept for years without ever producing a production engine. A prototype was demonstrated, running on the bench with no load.
Problems
The Sarich Orbital engine turned out to have a number of fundamental flaws that kept it from becoming a practical engine. Amongst other things, there are key components that cannot be cooled, and other components that cannot be easily lubricated.
Rise and Fall
The company founded specifically to develop the orbital engine has given up work on the design. However, a related piece of the design, an air-assisted direct fuel injection system, continues to be developed by the company. The system allows for stratified charge injection under light loads, but can switch to traditional fuel injection operation (the "air assist") when more power is needed and normal stratified charge designs have problems. This injection system is claimed to have application to both four stroke and two-stroke engines.
The Orbital company also lives on doing consulting and research work for other people's engines.
See also
External links
- Australian patent 467415 describing the orbital engine.