The rudder stock seal is an important component to ensure the sealing effect of the connection between the ship's steering gear and the hull. The following is a related introduction:
Function
Prevent leakage: prevent seawater or other liquids from entering the ship from the gap between the rudder stock and the hull, avoid corrosion and damage to the equipment and structures in the ship, and ensure the water tightness and safety of the ship.
Maintain lubrication: to a certain extent, it helps to maintain lubrication between the rudder stock and related components, reduce friction and wear, ensure the flexible rotation of the rudder stock, and improve the working efficiency and stability of the steering gear.
Protect components: prevent external impurities, pollutants, etc. from entering the rudder system, avoid wear, blockage or other damage to the rudder stock, bearings and other components, and extend the service life of various components of the rudder system.
Common types
Stuffing box seal: generally composed of stuffing box, gland, stuffing, etc. The stuffing is usually made of carbon fiber packing, asbestos rope and other materials, which are filled in the gap between the rudder stock and the stuffing box, and pressure is applied through the gland to make the stuffing fit tightly to the surface of the rudder stock to achieve the purpose of sealing. The advantages are simple structure, low cost and easy installation; the disadvantages are that the packing needs to be checked and replaced regularly, and the sealing effect may decrease under high pressure, high speed and other working conditions.
Sealing ring sealing: Common ones include O-rings, V-rings, etc. The O-ring uses its elastic deformation to form a seal between the rudder and the sealing groove; the V-ring is composed of multiple V-shaped rubber rings stacked together. Through the pressing force of the gland, the lip of the V-ring is in close contact with the rudder and the sealing groove surface to achieve sealing. The advantages of sealing ring sealing are good sealing performance, easy installation and long service life; the disadvantages are that the installation accuracy is high, and the sealing ring may age and deform under harsh environments such as high temperature and high pressure.
Mechanical seal: The sealing surface is formed by the close fit of the dynamic ring and the static ring to prevent liquid leakage. The dynamic ring is installed on the rudder and rotates with the rudder, while the static ring is fixed on the hull or steering gear. Mechanical seals have the advantages of good sealing performance, small leakage, and long service life, but they are complex in structure, high in cost, and have high requirements for installation and maintenance.
Working principle
Take the common stuffing box seal as an example. When the ship is sailing, seawater will exert a certain pressure on the rudder stock and try to enter the ship from the gap between the rudder stock and the hull. At this time, the stuffing in the stuffing box will be tightly wrapped around the rudder stock under the pressure of the gland, forming a sealing barrier to prevent seawater leakage. As the rudder stock rotates, the stuffing will produce a certain amount of friction with the surface of the rudder stock, but because the stuffing has good flexibility and wear resistance, it can adapt to the rotation of the rudder stock while ensuring the sealing effect.
