Abstract: According to the problem that the reverse rotation of the compressor caused by mis-operation in the reliability experiment of the variable frequency compressor leads to the wear and jamming of the parts, the research on the positive and reverse low speed pump oil of the variable frequency compressor is put forward. The two-phase flow simulation model of crankshaft oil pump based on VOF method is established by commercial fluid simulation software to study the influence of crankshaft oil path design on its oil pump capacity. Three kinds of oil path design are proposed: single-pass pipe oil path, double-helix cross oil path and double-helix non-cross oil path, and simulation and experimental test analysis are carried out. The positive rotation oil mass flow rate of the double helix non-cross oil path design running at 20 Hz is 8 g/Ts, and the reverse rotation oil mass flow rate is 6 g/Ts, which all meet the relevant oil mass flow rate standards, indicating that the double helix non-cross crankshaft structure can meet the reliability requirements of parts, and the compressor can operate at low speed and can be expanded to 20 Hz. Comparing the experimental and simulation results, the trend of simulated oil output is basically the same as that of the experiment, indicating that the crankshaft pump oil simulation model has high accuracy and could guide the crankshaft oil path design, which is of great significance for improving compressor operation and component reliability.

Key words: VOF model, Crankshaft oil path, Positive and negative rotation, Low speed oil pump, Reciprocating compressor