Analysis of Machining Technical Challenges for Ship Stern Tube Brackets

The ship stern tube bracket is a critical large structural component connecting the ships propulsion shafting and the hull, and its machining quality directly affects the stability and safety of navigation. Its machining process mainly revolves around large cast and forged blanks, including scribing and datum machining, hole machining, and finishing of end faces and mating surfaces. The core process is the high-precision boring of the stern tube bearing bore, which must ensure its roundness, cylindricity, and coaxiality with the theoretical centerline of the shafting. The technical challenges are significant: Firstly, the large size and complex shape of the workpiece make clamping, positioning, and deformation control extremely challenging. Secondly, during deep hole boring, the long overhang of the tool system can easily cause chatter, affecting surface quality and dimensional accuracy. Furthermore, for ships with two or more stern tube brackets, strict collinearity of multiple shaft holes is required, necessitating excellent process planning and machine tool accuracy. Finally, how to improve machining efficiency and control costs by rationally arranging process routes and selecting efficient tools and parameters is also a challenge in actual production. These factors collectively constitute the core challenges of high-precision, high-quality machining of stern tube brackets.