suspension design optimization of a hermetic compressor for improved vibrational behavior

Abnormalities in the vibrational behavior of driving motors and their side effects have always been a chief concern for home appliance manufacturers. hermetic compressors used in refrigerators are no exception in this matter. as a single-piston reciprocating machine with a crankshaft driven by a simple rotor-stator system, compressors can have noticeable vibrational dissonances. the compressor’s vibration is considered as a source of noise that can be transferred to other parts of the refrigerator and disturbingly excite them. despite multiple studies to isolate this vibration by removing or optimizing its pathways, the focus has never been directly on reducing the vibration of the main source. in this study, a 6 degree of freedom model of a refrigerator compressor is derived and then simulated in matlab-simulink. the model is then verified with the computational results of an equivalent model made in adams. all vibrating parts and their indexes are identified in order to design a new suspension system with improved vibrational behavior. a genetic algorithm is used to minimize an acceleration-based objective function considering six optimization variables including the stiffness parameters of springs and their arrangement. the optimized springs were built and tested under an actual compressor, and the time/frequency responses of the compressor were compared with the initial system. the results show the enhanced vibrational behavior of the compressor in its working frequency after optimization.