The Importance of Oil-Lubricated Stern Tube Bearing in Marine Machineries

Blog | October 14th, 2021

A stern tube is the watertight tube enclosing and supporting the propeller shaft. It comprises a cast-iron or projected steel cylinder fitted with a bearing surface within which the propeller shaft, encased in a sleeve, pivots. The stern tube is installed from toward the back and dashed to the stern casing chief. It very well may be press-fitted or installed with epoxy resin.

The stern tube bearing fills two significant needs. It upholds the tail shaft and a significant extent of the propeller weight. It additionally goes about as an organ to forestall the passage of ocean water to the machinery space.

The Importance of Oil-Lubricated Stern Tube Bearing in Marine Machineries

In principle, the stern tube rearward seals can work without an oil framework. Be that as it may, the toward the back sealing capacities better and has a more extended life in case it is fitted, similar to the forward sealing, with a grease framework. Albeit dated, long-lasting oil without flow is as yet utilised. Oil misfortune can happen in case there is no counter tension from the detachable water. The framework with the dissemination is more secure.

The rearward sealing is associated through two oil lines to a settling tank. The oil is flowed by a little oil siphon. Any seawater that has spilled through the harmed or worn water seals into the oil framework can be isolated out in the settling tank. Likewise, any oil that has gotten away from the oil seals can be drained into the waste oil tanks. Low and undeniable level switches on the settling tank permit clear perception and monitoring of the functioning of the toward the back seals.

Early plans utilised bearing materials like lignum vitae (an extremely thick type of wood) which were lubricated via ocean water. Most present-day plans utilise an oil grease course of action for a white metal lined stern tube bearing.

Oil is siphoned to the hedge through outside pivotal depressions and goes through openings on each side into internal hub entries. The oil leaves from the closures of the hedge and flows back to the siphon and the cooler. One of two header tanks will give a back strain in the framework and a time of oil supply in case of siphon disappointment. A low-level caution will be fitted to every header tank. Oil tension in the grease framework is higher than the static ocean water head to guarantee that ocean water can’t enter the stern tube in case of seal disappointment.

KEMEL EVK is one of the water-lubricated stern tube seals that this company offers to its clients. It has a simple design that provides superb sealing performance along with being resistant to shaft vibration. The way that the seal ring rotates prevents wear on the shaft sleeve. In addition, the shaft sleeve is covered with “Eagle Paint” to prevent corrosion. Parts are easy to replace, and this seal requires little maintenance. The shaft receives its lubrication from the sea water that passes through it.


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