STERN TUBE SEAL - A housing with series of seal rings clamped into position on the bush. Sterntube seals have to perform two separate functions, one is to ensure that water does not enter the engine room, the second one to allow the propeller shaft to rotate as smoothly and freely as possible.
The main function of stern tube bearings is to allow an unrestricted and smooth rotation of the propeller shaft. Apart from stern bearings, the stern tube also houses water and oil sealing glands known as the stern glands. The stern tube is a sensitive part of the ship where the sea water can easily seep inside.
The propeller shaft passes through the liner and is supported by the stern tube white metal bearings. These bearings are lubricated by lube oil and to prevent leakage of oil out at sea or ingress of water inside the tube, lip seals are attached at forward and aft part of the tube.
The lip seals create grooving over the chrome liner due to friction which can be overcome by using ceramic filler for the grooves or by using a distance piece with some allowance to compensate shaft and stern tube expansion. It also removes the problem of high temperature failure of seal.
17 окт 2024
