| 摘要 |
PURPOSE:To make it possible to minimize the stage number of packing by providing a variable restriction mechanism for uniformly adjusting the pressure of each back pressure chamber on a through hole pircing the packing back pressure chamber on each stage in a device inscribed on the face using multistage packing. CONSTITUTION:When packing 2 divided into a plural number in the circumferential direction is provided into a plural number of stages, i.e., 4 stages, and a main shaft 1 to whose outer periphery a main shaft liner 8 is fitted to water- sealed, the each packing 2 is inserted between a packing box 15 and a packing case 4, between the packing cases 4, 4 and between the packing case 4 and a cover 5. At this juncture, on the outside of the each packing 2, a back pressure chamber 7 is formed, and the each back pressure chamber 7 is communicated via through holes 18 mutually communicated provided on the packing case 4 and the packing box 15. And, between the respective stages of the through holes 18 a movable rod 19 is arranged providing variable restricting structure for uniformly adjusting the pressure in the each back pressure chamber 7. |
