Propeller Stern Shaft Seal Includes Tail Seal And Front Seal

The propeller can balance the pressure of water, and the oil can lubricate the sealing ring and reduce the wear speed of the rubber ring. The red pipeline is air, and the yellow pipeline is lubricating oil. Two air rings and two oil rings are formed between the shaft and the shaft tube. The pressure of compressed air at the gap is always higher than that of sea water, so the sealing effect is achieved. Stern shaft seal includes tail seal and front seal.
If the tail seal leaks, the water pressure enters between the two sealing rings, causing the oil level in the gravity oil tank to rise, and the monitoring alarm system will alarm. The bridge knew there was a problem with the rear seal. The front seal is connected to the engine room, and there is little water ingress problem. However, if the front seal ring is damaged, the seal oil leaks out, causing the oil level in the gravity oil tank to drop, and the monitoring system alarms, it will know that the front seal is faulty.
Safety and energy-saving propeller six-blade rear view
Of course, it is the seal. Let's first look at a main component. The shaft connecting the propeller is called the stern shaft, which is at the end of the ship's large steel shaft. The sealing capacity of stern shaft is an important reflection of the technical level of a country's shipbuilding industry. The stern shaft of large ships is installed on two bearings. One is called tail bearing, which is the part of the ship in contact with water; The front bearing is connected to the engine room, and the tail shaft compartment is between the front and rear bearings. The sealing of the hull depends on the sealing ring installed beside the front and rear bearings. Generally, the front and rear bearings have several sealing rings. The two sealing rings are filled with oil, which is called large shaft oil seal. This oil comes from the oil tank at a certain height, which is called gravity oil tank.