What are the types of stern tube seals?
Different Types of Stern Tube Seals
- labyrinth Seals.
- Mechanical Face Seals.
- Packing Type.
What is the stern tube arrangement?
The stern tube is a hollow tube passing at the lower stern part of the ship carrying tail shaft and connecting it to the propeller out at sea, bearing for the tail shaft, lubrication arrangement and most importantly the sealing arrangements.
How do ships seal propeller shaft?
Face seals compress a fixed bearing against a collar attached to the shaft. A small amount of water forms on the interface between the stainless and the carbon, lubricating the seal. An attached hose connects the fixed bearing to the stern tube.
Why stern tube seals are provided?
Stern tube seals are a key component of the propulsion system of a ship. The purpose of these sealing rings is to ensure a reliable sealing condition, preventing the spillage of lubricant to the environment.
What is the arrangement of oil lubricated stern tube and tail shaft?
Oil lubricated sterntube requires two types of seals, one water/oil seal for the external arrangement (aft seal) and one oil seal for the inboard end (forward seal). Modern sterntube seals are highly-engineered units designed and manufactured to withstand a rigorous working environment for long periods.
What is a stern seal?
Stern tube seals for inland and seagoing vessels The aft seal prevents seawater from contaminating the stern tube oil, which may possibly jeopardise the lubrication properties of the oil, leading to extensive bearing wear. The aft seal also prevents oil leaking into the marine environment.
What is stern tube seal?
What is tail shaft of a ship?
Definition of tail shaft : the after section of a ship’s propeller shaft extending through the stern tube.
How does a shaft seal work?
A common type of shaft seal consists of an elastomer (elastic rubberlike) ring bonded to a metallic ring that is a press (tight) fit in the hole in the housing through which the shaft extends. The sealing is done by a lip on the elastomer ring that is pressed snugly around the shaft by a helically wound garter spring.
How does shaft seal work?
What is a shaft seal on a ship?
Shaft seals are essential to the reliability and environmental compliance of a vessels primary shafting. They sit either on the forward end or both the aft and forward ends of a Stern tube on the conventional shafting of a vessel. They can also be found on Thruster or podded type propulsion units.
What is propeller shaft seal?
What is thrust shaft arrangement?
The thrust loading is carried by bearing pads which are arranged to pivot or tilt. The pads are mounted in holders or carriers and faced with white metal. In the arrangement shown the thrust pads extend threequarters of the distance around the collar and transmit all thrust to the lower half of the casing.
Where is a shaft seal located?
The shaft seal is placed around the rotating shaft, at which point it seals the oil- or lubricant-filled passage. Even if the oil or lubricant is pressurized, it shouldn’t leak. The shaft seal’s lip will wrap around the rotating shaft.
What is the difference between mechanical seal and shaft seal?
Oil or Rotary shaft seals are vulnerable to extreme temperatures, which can cause them to wear out faster if they are used in very high or low temperatures. A mechanical seal features stationary elements, rotating components and a spring.
How many types of shaft seals are there?
There are three basic types of shaft seals with different construction forms: A, B, and C. If the shaft seal contains a dust lip, an S is added. If it seals from both directions for two different fluids, a “D” is added. An “O” in the type means no garter spring.