explain:

The rudder seal has the characteristics of compact structure and easy maintenance. Suitable for use in situations with small axial dimensions.

Definition and Function

The rudder seal device is a sealing device installed at the point where the rudder of a ship passes through the hull structure. Its main function is to prevent substances such as seawater, rainwater, and oil from entering the ship's interior, while also avoiding the leakage of lubricating oil and other liquids from the ship's interior to the outside. It can ensure the normal operation of the servo system, protect the rudder stock and rudder bearings of the ship from corrosion and damage, and is a key device to ensure the safety and normal operation of ship navigation.

Structural composition

Sealing element:

The sealing element is the core part of the rudder stem sealing device, usually including lip seals, O-ring seals, etc. Lip seals are generally made of rubber material and have a lip like shape, with the lip in close contact with the rudder stock. When the rudder stock rotates, the elastic lip of the lip seal can adapt to the movement of the rudder stock and always maintain a sealed state. O-ring seals rely on their own elastic deformation to fill the sealing gap and play a sealing role. These sealing components need to have good elasticity, corrosion resistance, and wear resistance to adapt to the movement of the rudder stock under different working conditions and harsh marine environments.

Cover and liner:

The gland is used to fix and press the sealing element, and it is usually connected to the hull structure or the outer shell of the rudder seal device through bolts or other connectors. By adjusting the tightness of the cover, the clamping force of the sealing element on the rudder stock can be controlled. The liner is generally installed between the rudder stock and the sealing element, mainly serving to support and guide the rudder stock. The lining material is mostly wear-resistant and corrosion-resistant metal, such as bronze, which can reduce the wear of the rudder stock and withstand certain radial forces, ensuring the stability of the rudder stock during rotation.

Protective shell:

The protective shell is mainly used to protect the internal sealing elements and other components from damage from the external environment. It is usually made of metal material and installed on the hull structure, surrounding sealing elements and pressure covers and other components. The protective shell can prevent direct impact of seawater, debris, etc. on the sealing device, while also providing a relatively stable working environment for the sealing device.

working principle

When the rudder stock rotates in the sealing device, the sealing element tightly adheres to the rudder stock and liner (or hull structure) under the pressure of the cover. Taking lip seals as an example, their lips will undergo elastic deformation during the rotation of the rudder, always maintaining contact with the surface of the rudder, preventing liquids or debris from entering from the outside or leaking from the inside. For O-ring seals, they rely on their own elasticity to fill the gap between the rudder stock and surrounding structures, forming a sealing barrier. At the same time, the liner supports and guides the rudder stock, ensuring the stability of the rotation axis of the rudder stock, which is beneficial for the sealing element to better perform its sealing function.

advantage

Good sealing performance: The rudder stem sealing device can effectively prevent leakage and invasion of seawater, oil, etc., ensuring good sealing effect whether in a stationary state or a rotating state of the rudder stem. This is crucial for protecting the internal equipment of the ship and maintaining the normal operation of the servo system.

Adapt to the movement of the rudder stock: Due to the good elasticity and adaptability of the sealing element, it can adapt well to the rotation and certain axial displacement of the rudder stock. This ensures that the movement of the rudder stock within the normal operating range does not affect the sealing performance of the sealing device.

Durability and reliability: The use of high-quality sealing elements, bushings, and protective shells ensures that the rudder stem sealing device has high durability. It can work reliably in harsh marine environments where ships sail for a long time, reducing the trouble of frequent replacement of sealing devices and lowering the maintenance cost of ships.

Disadvantages and countermeasures

Sealing element wear issue: Due to frequent rotation of the rudder stock and friction between the sealing element and the rudder stock, the sealing element is prone to wear. Once severely worn, it may lead to seal failure. The countermeasure is to regularly check the wear of the sealing components, and replace them in a timely manner when the wear exceeds the specified limit. Meanwhile, sealing materials with better wear resistance can be used to extend their service life.

The installation and debugging requirements are high: the installation accuracy and debugging process of the rudder seal device have a significant impact on its sealing performance. If installed improperly, such as inaccurate installation of sealing components, improper tightening force of the pressure cover, etc., it may lead to poor sealing effect. Therefore, it is necessary to strictly follow the installation instructions for installation and debugging, and be operated by professional personnel.

Application scenarios

Sealing of rudder stock for various types of ships: Whether it is cargo ships, passenger ships, oil tankers, or warships, rudder stock sealing devices need to be installed wherever the rudder stock passes through the hull structure. It is an essential component of the ship's servo system, ensuring accurate and safe steering operations during navigation.