Abstract: In order to achieve the requirement of high volume rate of refrigerators, frequency conversion reciprocating compressors are becoming more and more miniaturized. If the excitation source is not balanced or the vibration isolation measures are improper, it will cause problems such as large vibration of the compressor at low speed. By analyzing the vibration excitation source and transmission path, it is found that the unbalanced force is the main reason for the low-speed jitter of the compressor. It is clear that the components such as the inner exhaust pipe, the seat spring and the foot pad play an important role in the transmission of vibration. The insufficient lateral stiffness of the compressor foot pad can easily lead to large vibration of the compressor at low speed. Through dynamic balance optimization and pad optimization design, the vibration of X, Y and Z directions at low speed meets the customer test standards. At the same time, in the X direction with large amplitude, the vibration at low speed decreases by 31.8%~55.9%. The problem of large vibration of compressor at low speed is successfully solved, and the adaptability of miniaturized frequency conversion compressor to refrigerator system at low speed is improved.

Key words: Miniaturized variable frequency compressor, Low speed jitter, Unbalanced inertial force, Transfer path