Kinematic Structure of Mechanisms for Fixed and Variable-Stroke Axial-Piston Reciprocating Machines

The creation of mechanisms according to the separation of kinematic structure and function has been carried out for a class of three-dimensional mechanisms suitable for conversion between rotary and reciprocating motion in axial engines, pumps and compressors. The structural and kinematic classification of such mechanisms has been established and a suitable search specification formulated with its aid. The resulting search has yielded fifty linkage configurations which have been determined to be possible candidates for such motions. These have four links, one degree-of-freedom and incorporate rotary, sliding, cylindrical, ball, and plane joints. Eleven of these linkages show sufficient promise to be considered for additional evaluation. Several of the linkages have a double-frequency motion of the floating link which would be suitable for a swash-plate drive. These linkages appear to be particularly promising because the double-frequency motion would reduce the stroke and swash-plate speed by one-half compared to a conventional swash-plate drive of the same displacement.