Abstract: The refrigerator reciprocating compressor usually has many different design methods on the ratio of piston-stroke to cylinder-diameter (stroke-to-diameter ratio for short). Based on influences on different stroke-to-diameters of reciprocating compressor, investigates the mechanism of shaft-connecting rod-piston on reciprocating compressor, analyses the dynamic characteristics on the influence of different stroke-to-diameters ratio. It is observed that the stroke-to-diameter has no influence on the resist-torque. Increasing the stroke-to-diameter appropriately can reduce the side-force of piston and the friction force of piston, enhances the refrigeration capacity and the coefficient of performance.

Key words: Reciprocating compressor, Stroke/diameter ratio, Moment of resistance, Side force