The Jonova engine / Jonova Motor is a type of pistonless rotary engine, designed originally by John Nowakowski - its name was given to a recent design by student engineers at the University of Arizona.
Consisting of only four moving parts, the newer Jonova engine loses no energy through vibration and has a wide power stroke over 240 degrees of rotation, as opposed to four-stroke engines which have a power stroke of 180 degrees on alternating rotations or two-stroke engines with a power stroke of 180 degrees on each rotation.
References
Jonova engine Wikipedia(Text) CC BY-SA