Rudder bearings are used to support the weight of the rudder stock and rudder, and to ensure the watertightness of the ship. They are divided into two types according to their position of installation: upper rudder bearings and lower rudder bearings.

The upper rudder bearing is installed on the deck between the servos, as shown in the following diagram. It consists of side thrust roller bearings and vertical sliding bearings, with ball bearings bearing the weight of the rudder and vertical bearings bearing lateral forces.

The lower rudder bearing is generally installed at the mouth or inside the rudder barrel, and its structure is shown in the figure. It is a vertical sliding bearing that bears lateral forces and is equipped with a packing box to ensure water tightness. The hanging rudder adopts two rudder bearings, upper and lower.

At present, large ships are generally only equipped with rudder bearings, which bear all the weight and force. Their structure is shown in the diagram. This type of rudder blade is often equipped with a detachable rudder shaft (through the center rudder shaft). The upper end of the detachable rudder shaft is fixed to the stern with a flange, and the lower end passes through the stern column seat and is fixed with a nut. The upper and lower ends of the welded pipe through which the detachable rudder shaft passes are equipped with iron pear wood or bronze bearings, and the contact points of the detachable rudder shaft bearings have copper bushings to prevent wear and tear of the rudder shaft. When turning the rudder, the rudder blades rotate around the detachable rudder shaft. For small ships, in addition to being equipped with rudder bearings, a rudder pin (rudder pin) is installed at the bottom of the rudder blade. There is a detachable small door at the rudder blade where the rudder pin is installed to facilitate the disassembly and assembly of the rudder pin. The other end of the rudder needle is inserted into the vertical sliding bearing of the tail column seat and can rotate freely.