Perpustakaan Digital ITB

The hoisting system of a shiplift is responsible for lifting and lowering the lifting platform with large vessels on top of it which then can be maintained further at a shipyard's dry dock area. The gearbox of the hoisting system is responsible for reducing the speed of the pulley and increasing the input torque from the electric motor according to the desired total gear ratio of the gearbox. In this undergraduate thesis, the gearbox design is carried out for a specific shiplift‘s hoisting system according to a specified design requirement. The design includes main components such as gears, shafts, bearings, and housing. After the design requirement and objectives (DR&O), the process is carried out by formulating alternative designs followed by a decision matrix to select the best design. The design will go through some configuration processes before continuing to the detailed design. The gear design will use AGMA 2001-D04 as the standard, the design of the shaft will use DE-Soderberg and DE-Gerber, while the design of the bearing will use ABMA as the standard. Based on the analysis and design process, the gearbox has 5 stages of planetary gear set with different number of planet gear ranging from 3 to 5 planet gears. The whole gearbox system has a gear reduction ratio of 1:653 with inputs of 328 rpm & 693 Nm and outputs of 0.51 rpm and 447 kNm. The main drive of the gearbox is an asynchronous AC motor from SEW Eurodrive. Conventionally, the output of the gearbox system is carried out by shaft. However, this design uses the planet carrier at stage 5 as the output that is directly connected with the drum of the hoisting system. The idea is to maximize the space usage by putting 4 stages inside the drum while the fifth stage transmits the torque from the side of the drum. The results show that this design fulfills all of the requirements and objectives of the hoisting system especially in terms of torque capacity, reduction ratio, safety factor, and space constraint.