The free-piston engine was proposed by R.P. Pescara [1] and the original application was a single piston air compressor.
Free-piston air compressors were used, among others by, the German Navy. They were efficienct, compact and quiet.[2]
These are of the dual piston type, creating a compact unit with a high/weight ratio. This design requires an electric machine of for low weight. Difficulties in the form of low cycle-to-cycle rates have been reported for dual piston engines.[3][4]
Several free-piston gas generators were created, and these were in widely used in large-scale applications such as stationary and marine powerplants.[5] Current research suggests these could be more efficient than internal combustion engines.[6]
Categories: [Technology] [Engine]