As a result of intense competition, years of design refinement, and strong customer preferences for performance, environmental cleanliness, and efficiency, the conventional piston engine configuration has been brought to a high degree of refinement in its principal applications such as automotive, light aircraft, and marine use. Other uses, such as for emergency rescue, robotic, or military power may require further development focused more intensely on power output, compact size, quiet operation, fuel efficiency, or even throw away economics.
This paper focuses on a new design that shows promise of compactness, low internal friction and vibration levels (leading, respectively, to further efficiency gains and noise reduction), and higher power to weight ratios. The proposed design is based upon an axial piston configuration known as a Z-crank engine, in which cylinders of the engine are arranged around the shaft axially in the same way as are the chambers of a 6-shooter revolver. This type of engine is also known as a “Barrel Engine” because the cylinders are similar to the staves around the outside of a barrel [1]. The output shaft is at the center of the cylinder block, and is linked to the pistons by a wobble plate or a swash plate.