Physical picture of flanged rubber bearing:

The working medium for the stern tube of a ship is water, and it is recommended to use this rubber bearing.

The rubber bushing is suggested to be used when the lubricating medium of stern tube is water.

Production cycle: 7 days

Warranty period: 1 year

Certificates available: CCS type approval certificate, CCS product certificate, Korean KR, German GL, French BV and other certificates.

Structural characteristics

Rubber body part: The core part of the flanged rubber bearing is the rubber layer, which is made of wear-resistant and seawater corrosion-resistant rubber material, such as nitrile rubber. This rubber material has good elasticity and can undergo appropriate elastic deformation during the rotation of the shaft neck to adapt to the movement of the shaft neck. The inner diameter size of the rubber layer is closely matched with the shaft neck, ensuring good support for the shaft neck during rotation and forming an effective water film lubrication between the two.

Flange section: The flange is a prominent feature of this bearing. Flanges are usually located at both ends of bearings and are typically made of metal materials such as cast iron or steel. The main function of flanges is to facilitate the installation and fixation of bearings. It can be firmly connected to surrounding structural components (such as stern tubes) through bolts and other connectors, ensuring the stable position of the bearings during ship operation and preventing axial displacement. At the same time, the flange can also play a certain sealing role, preventing excessive impurities such as seawater from entering the interior of the bearing.

working principle

When the journal rotates in a flanged rubber bearing, the rubber layer comes into contact with the journal. Due to the elasticity of rubber and the rotational motion of the shaft neck, a water film will form between the shaft neck and the rubber layer. This water film is formed by the rotation of the shaft neck, which drives the surrounding seawater (for marine bearings) or fresh water (in the case of a fresh water lubrication system) into the gap between the shaft neck and the rubber. The water film separates the journal and rubber layer, shifting the friction mode between them from dry friction to water film friction. This type of water film friction greatly reduces friction, reduces wear on the journal and rubber bearings, and also contributes to the efficient operation of the ship's shaft system. For example, during the navigation of a ship, the propeller drives the stern shaft to rotate, and the stern shaft neck rotates smoothly in a flanged rubber bearing, relying on this water film to achieve low friction operation.

advantage

Installation convenience: The presence of flanges makes the installation process of bearings easier and faster. By fixing the flange in the corresponding installation position with bolts, the bearing can be accurately positioned and the installation accuracy is easier to control. Compared with some bearings that require complex nesting or interference fit installation methods, flanged rubber bearings can save installation time and labor.

Good sealing: The flange can to some extent prevent seawater, impurities, etc. from entering the interior of the bearing. In the harsh environment of ship navigation, seawater may contain corrosive substances such as sediment and salt. Good sealing can reduce the erosion of these impurities on the rubber layer and shaft neck, and extend the service life of bearings.

Reliable axial positioning: The flange can effectively limit the axial movement of the bearing, ensuring the stable position of the journal in the axial direction. This is very important for the normal operation of the ship's shaft system, because if the shaft system experiences axial displacement during operation, it may lead to increased local wear of the journal and bearings, and even damage to other related components.

Disadvantages and countermeasures

Flanges are prone to corrosion: As flanges are usually made of metal and exposed to seawater, they are prone to corrosion. Corrosion may lead to a decrease in the connection strength of the flange, affecting the fixing effect of the bearing. To address this issue, anti-corrosion treatment can be applied to the flange, such as coating with anti-corrosion paint, using anti-corrosion processes such as galvanizing, or using corrosion-resistant alloy materials to make the flange.

Increasing weight and space occupation: The presence of flanges increases the overall weight and volume of bearings, and this factor needs to be considered in ship design for its impact on the center of gravity and spatial layout. In the case of limited space, it may be necessary to plan the installation position of bearings reasonably. At the same time, heavier bearings may have indirect effects on the fuel consumption and other performance of ships, which need to be comprehensively balanced in the design phase.

Application scenarios

Ship stern shaft support: In the stern shaft system of ships, flanged rubber bearings are widely used to support the stern shaft. When a ship is sailing, the stern shaft requires stable support to ensure the normal operation of the propeller. Flanged rubber bearings can meet this requirement and are fixed to the stern shaft tube through flanges to provide reliable support and axial positioning for the stern shaft.

Equipment such as ship axial flow pumps: In some rotating equipment such as axial flow pumps on ships, flanged rubber bearings are also used. These devices also require good bearings to support the shaft neck and operate in an aqueous environment. The water lubrication characteristics and installation convenience of flanged rubber bearings make them a suitable choice.