抄録
Occurrence of cavitation in hydrodynamic bearings has been one of the most famous subjects, and there are a lot of papers on the condition of cavitation occurrence especially for plane journal bearings. With the development of surface texturing technology, more interests in the conditions of cavitation occurrence in the textured area has been taken again, especially for the case that the negative pressure area was fully surrounded by the operating fluid in the textured bearings. However, it is still unclear how much the negative pressure is needed for cavitation occurrence in the textured bearings and how much the pressure value in the cavitation area is. In this study, we designed and manufactured a visualization equipment consisting of a herringbone-grooved hydrodynamic bearing and observed the cavitation length and measured the pressure value in the cavitation area depending on the rotational speed. We used three kinds of lubricants, hexadecane, tetradecane and dodecane, as the operating fluids. The main experimental results are that: (1) for the occurrence of cavitation in the bearing clearance, negative pressure much less than the atmospeheric pressure was necessary. (2) the growth rate of the cavitation length in hexadecane became the largest because the change in solubility of air in hexadecane against rotational speed was the largest, (3) the pressure value in the cavitation area became closer to the atomospheric pressure as the length of the cavitation area was larger.
