Studies Regarding Redesign and Optimization of the Main Shaft of a Naval Winch

Abstract

This article presents the results of a study regarding the structural optimization of the main shaft of a naval winch and its manufacturing technology. Throughout this paper, its design will also be changed and improved. The main purpose of the research here described is to reduce the mass of the shaft from an initial weight of 23 kg. The drum responsible for releasing the boats in the water is placed on the first section of the spindle. The maximum embarkation is 2141 kg (21kN), meaning the safe working load of the davit, consisting in a boat fully equiped with 10 people in it. Moreover, this value of 2141 kg, is multiplied with the safety factor of a minimum 4.5, specific for the maritime industry, in the proceeded analyzes. The other objectives of the study take into consideration the fulfiling of the functional role without having a major intervention upon the other components of the winch, the reduction of costs and the decreasing in manufacturing time. Therefore, starting from a hollow byproduct, through the processes of optimization, redesign and simulation using finite element analysis, the achieved results show a 45% reduction in the weight of the shaft and a significant shortage of the manufacturing time. In this entire proceess, only one component needs technological changes by repositioning its 4 holes. From the economical point of view, by using a tube instead of a bar, it is possible a reduction of almost 6000 USD for a batch of 1000 shafts.