The main types of stern shaft sealing apparatus

The main types of stern shaft sealing apparatus


The stern shaft sealing apparatus is a key component in the ship's propulsion system, used to seal the ship's shaft inside the stern shaft tube, prevent seawater from entering the ship, and prevent lubricating oil from leaking into the sea. This device plays an important role in ensuring the normal operation and environmental protection of ships. The main types of stern shaft sealing devices: Packing Seals, Mechanical Seals, Lip Seals and Air seals.

Overview

The main types of stern shaft sealing devices

1. Packing Seals:

Features: Fill the sealing chamber with packing materials (such as asbestos, rubber, or polytetrafluoroethylene), and achieve sealing effect by compressing the packing.

Advantages: Simple structure and low cost.

Disadvantage: Regular maintenance and replacement of packing are required, resulting in relatively poor sealing effect.

2. Mechanical Seals:

Features: Composed of dynamic and static rings, it maintains contact through springs or magnetic force to achieve dynamic sealing.

Advantages: Good sealing effect and long maintenance interval.

Disadvantages: Complex structure and high cost.

3. Lip Seals:

Features: A lip sealing ring made of rubber or other elastic materials, which utilizes the elasticity of the lip to tightly adhere to the surface of the shaft for sealing.

Advantages: Simple structure and convenient installation.

Disadvantage: Under high pressure and high speed, the sealing effect may not be ideal and it is prone to wear.

4. Air Seals:

Features: Utilizing compressed air to form a gas barrier, preventing the penetration of water and oil.

Advantages: No contact wear and tear, long service life.

Disadvantage: An additional air compression system is required, which is costly.

Maintenance and upkeep of stern shaft sealing device

Regular inspection: Regularly check the condition of the sealing device to ensure that there is no wear or aging phenomenon.

Replace seals: Based on usage and manufacturer recommendations, regularly replace seals to ensure sealing effectiveness.

Lubrication maintenance: For sealing devices that require lubrication, regularly inspect and add lubricating oil or grease.

Cleaning and anti-corrosion: Keep the sealing device clean to prevent the erosion of seawater or other corrosive substances.

The stern shaft sealing device plays a crucial role in ship operation. Choosing the appropriate sealing type and conducting regular maintenance and upkeep is an important measure to ensure ship safety and environmental protection.

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