High speed reciprocating refrigeration compressors are designed and manufactured for many years of maintenance- free service. Particular attention must be paid to wearing parts such as bearings in order to insure that the conditions of load and lubrication are compatible with long life. The dynamic characteristics of the piston-connecting rodcrankshaft linkage, together with the gas and frictional forces on the mechanism, determine the bearing forces. A mathematical model which simulates this mechanism enables the designer to optimize many design features before manufacturing and testing pilot models.

The thermodynamic analysis of a high speed compressor also requires detailed knowledge of the behavior of the slider-crank mechanism. Indeed, the thermodynamic and mechanical aspects of the refrigeration compressor are so closely linked that accurate analysis and simulation of both phenomena are required for rational design. This paper describes an accurate simulation of the slider-crank mechanism which has been used extensively by the authors for analyzing and optimizing refrigeration compressor designs. The formulation presented here differs from the "classical approach" presented by J. P. Den Hartog (l) in that it eliminates the need for the following assumptions.

1. Uniform crankshaft velocity.
2. The connecting rod may be replaced by two masses, one at each end, so that the center of gravity is unchanged and the sum of the two concentrated masses equals the total mass of the original connecfing rod.