found: Work cat: Kutenev, V.F. Axial internal combustion engine, 1994.
found: The Museum of RetroTechnology WWW home page, Sept. 13, 2016power generation--unusual internal combustion engines/axial IC engines (Axial internal-combustion engines, also known as barrel engines. ... An axial or barrel engine has multiple cylinders arranged around and parallel to a central shaft, like the chambers in the cylinder of a revolver. The piston thrust is usually converted to rotary motion by a swashplate or Z-crank mechanism. The claimed advantages for this engine format were low frontal area (important for powering aeroplanes) very good balance and great compactness. On the downside there were major problems with the swashplate or wobble-plate mechanisms, and access for maintenance was poor. The axial IC engine was an obvious development of the axial steam engine. No axial IC engines have achieved any sustained success)
found: McLanahan, J.C. Barrel aircraft engines : historical anomaly or stymied innovation?, 1998:p. 1 (Barrel engines are reciprocating, internal combustion engines that have their cylinder axes parallel to and arrayed like barrel staves around the axis of the central power shaft. ... Early models of barrel engines resemble radial engines whose cylinder jugs have been bent backwards parallel to the air flow. Various drive mechanisms, involving gears, cams, or wobble plates, are used to create rotation of the central power shaft from the reciprocating motion of the pistons)
found: Duke engines WWW home page, Sept. 13, 2016What type of engine is the Duke engine? (The Duke engine is a four stroke "axial" reciprocating engine. "Axial" because the axis of each cylinder is aligned with the axis of the output/crank shaft. Axial engines are sometimes called 'barrel' and 'z-crank' engines. The former refers to the cylindrical shape of the cylinder group whilst the latter alludes to the shape of the crankshaft. The barrel shape is a result of the pistons being spaced evenly around the central crankshaft and aligned parallel to the crankshaft axis. The 'z' in the crank provides the journal surfaces upon which the combustion loads (via conrods and then a swashplate, or [in] the case of the Duke engine a 'reciprocator') act to provide the driving torque of the engine)
found: Random House Webster's unabridged dictionary, 2001(barrel engine -- engine having cylinders arranged around and parallel to a shaft, which they rotate by means of the contact of their piston rods with a swash plate or cam on the shaft)
found: Google search, Sept. 14, 2016("Barrel engines" -- 9,720 hits; "Axial engines" -- 4,160 hits; "Axial internal combustion engines" -- 2,470 hits; "Z-crank engines" -- 800 hits; "Axial IC engines" -- 23 hits)
