| 摘要 |
A sealing device for rotating shafts, in particular a stern tube seal for a ship's propeller shaft 4 with or without a shaft sleeve 4a comprises sealing rings aligned with and contacting the shaft and arranged in a stationary carrier system 5, preferably a slide ring seal 6. A reserve seal 8 is arranged in the carrier system, the reserve seal being formed as a stuffing box seal 14 with soft packings and a stuffing box ring 13 displaceable in the axial direction in a guide body connected to the carrier system. The ring is actuated to activate the reserve seal by a plurality of individual piston-in-cylinder units (11, 11b, 13) which are uniformly distributed around a circle concentric to the shaft axis and with each of which there is associated a respective branch flow (17a) of the hydraulic or pneumatic pressure medium. Thus the reserve seal continues to operate even when one of the individual piston-in-cylinder units becomes leaky. There is a manual override 9 which can be operated if all the piston-in-cylinder units leak, and a resetting mechanism 16. |
