The marine propeller shaft is divided into three main parts: Thrust shaft, Intermediate shaft, and Tail shaft.
The thrust shaft is the main shaft coming out of the engine. It directly receives the rotary motion from the crankshaft and rotates at maximum speed in a high-speed engine.
For high-speed engines, the thrust shaft is also connected to other components further back.
The next component is the intermediate shaft. There is no particular limit to the number of intermediate shafts that a ship can have. However, more than 2 axes may be difficult to maintain and maintain. The reason is that the catenary force acting on the entire propeller shaft is large. Due to the weight of the component, this force easily deforms and damages the component.
Coupled with the huge vibration impact on the shaft, it may cause permanent damage to the propeller shaft. Therefore, a small number of intermediate shafts are preferred. The only reason for having multiple intermediate shafts is that the engine is located away from the propeller.
The last part is the tail shaft. It is directly connected to the propeller and is mainly installed in the stern tube. The stern shaft is connected to the intermediate shaft through a gearbox that controls torque transmission. The construction of the stern shaft can withstand various forces that may act on the stern.
Tail shaft arrangement
The next component is a coupling bearing connecting two adjacent shafts. The coupling is achieved by joints that are usually rigid and not bent. Bolt the connection units to each other using high-strength fasteners that can withstand large amounts of vibration stress.
Shaft bearings are components used to support and bear shaft loads. They run along the length of the shaft and ensure smooth rotation. These bearings are constructed differently according to their location.
The final part of the marine propeller shaft system is the thrust block. These blocks regularly support the propeller shaft. These blocks play a role in transferring excess power from the shaft to the hull.
When the shaft rotates at a very high speed, some vibration occurs. This further leads to vibrations, which may damage the structural integrity of the container. Therefore, the use of special bearings can spread the impact on the hull.
In order to anchor these thrust blocks to the bottom of the ship, a reinforcement frame was built. There is a main thrust block behind the engine crankshaft, which can distribute most of the vibration to the hull girder and structure.
The components discussed above constitute most of the parts that make up the driveshaft. In addition, there are many smaller parts, such as sealants and bearings, which play different roles.