| 摘要 |
PURPOSE:To give a high sealing performance to a seal of a shaft penetrating the boundary area between the high pressure and low pressure spaces, by fitting a bearing housing (partition member) and a piston in the shaft penetrating part with a certain spacing kept from each other and by setting two or more O-rings to have sealing. CONSTITUTION:A rotary shaft 1 as propeller shaft for an underwater vessel is so arranged as to penetrate the boundary zone between a high pressure space HS under seawater and a low pressure space LS as engine room, where the shaft 1 is borne rotatably by a bearing 9 installed in a housing 3, which is fixed 6 to a receptacle table 2 and functions also as partition plate. In this boundary zone a piston 4 fitted with O-rings 13-15 at the internal and outside circumferential surfaces is set on the rotary shaft 1, and an intermediate room MS is formed between the piston 4 and housing 3 to be filled with oil, which is poured from an inlet to be blocked by a plug 5. Thereby the pressure P2 in the intermediate room MS becomes higher than the pressure P3 in the low pressure space LS. A return spring 7 is interposed between the housing 3 and piston 4. |
