PURPOSE: To prevent seizure, by providing the tilting center portion of a shaft with a sealing means comprising an annular groove for keeping discharged gas from blowing through to an intermediate chamber and a spiral groove communicating with the annular groove, to cause oil film pressure on a bearing.
CONSTITUTION: A shaft 9a tilts in an upper plain bearing 11 and a lower plain bearing 12. At that time, the clearance 38 between the sliding surface 37 of an annular groove 35 and a spiral groove 36 communicating with it and the shaft 9a opposite the loaded side is small. As the bearings 11, 12 wear with the lapse of time, the shaft 9a tilts and the clearance 38 opposite the loaded side is kept nearly equal to its original value corresponding to the unworn state of the bearings. For that reason, discharged gas is prevented from blowing through the clearance 38.
TOUJIYOU KENJI
UCHIKAWA NAOSHI
MURAYAMA AKIRA
| JPS6316562A | 1988-01-23 |