Study on two-phase lubrication characteristics of the meshing pair in a single-screw compressor

In this paper, the lubrication state of the meshing pair in a single-screw compressor is analysed. The two-phase lubrication flow field numerical calculation model and the multi-tooth coupling circumferential torque calculation model are established. The oil film pressure and the circumferential torque of multi-tooth at 0%-60% air volume fraction (AVF) inlet are studied. Results show that the AVF at the inlet plays an important role in the promotion of the peak and average pressures of the oil flow field for certain star-wheel rotation angles. For other star-wheel rotation angles, the aforementioned pressure may even be weakened. For multi-tooth coupling, the star-wheel circumferential torque with inlet AVF of 20%, 40% and 60% is 15.3%, 13.1% and 6.8% higher than that with inlet pure oil, respectively. This shows that the existence of bubbles at the inlet increases the unbalanced circumferential torque of the star-wheel and increases the possibility of wear of the teeth.