Frictional energy analysis of a vane-type air pump for assisting paper handling via air flow in offset printing machines

摘要

Today, the technical subject for the air pump used in the offset printing machine is to reduce sliding friction and wear of vanes. If we could improve the energy efficiency, we could successfully design a smaller air pump with a longer life. In this paper, first of all, total power consumption of the air pump was measured by axial torque and analyzed according to components of a frictional force. As a result, it was found that most of the power is consumed at the sliding face between vanes and housing cylinder in the air pump. The power increases significantly due to the sliding friction between the vanes and their guide slots of the rotor, especially when the vanes are forced to move inward. On the basis of these results, the importance of the sliding friction of the vanes was confirmed quantitatively and the arising mechanism of the sliding friction of a vane against the slot face of the rotor was investigated theoretically as well as experimentally, and finally, we proposed some counter measures to reduce the sliding friction of vanes.