Optimum Stiffener Layout for the Reduction of Vibration and Noise of Gearbox Housing

Abstract

Dynamic excitation from the gears generates vibration modes in the gearbox which causes radiation of unwanted structure-borne noise. To reduce the noise as well as the vibration, the stiffened plate construction is frequently used for the housing, where the rib stiffener layout is the key to this design. In this paper, the most effective position of stiffeners in order to reduce the vibration and noise radiation is searched and discussed. The analysis considers first a plate fixed at edges and excited at its center, and then a simplified rectangular gearbox excited at the shaft bearing locations. The housing of a simplified single-stage gearbox is modeled by triangular finite shell elements. It is excited by a set of harmonic forces which are applied at the bearing positions. The rib stiffener is modeled by beam elements, and its optimum layout is searched by a genetic algorithm. The vibration energy is adopted as the objective function to be minimized for the design for low vibration. On the other hand, the radiated sound power is the objective function for low noise. Although the noise is caused by the vibration, the optimum stiffener layout to realize low noise is not always identical to the layout that yields low vibration because of the difference in radiation efficiency. This is numerically clarified first from the viewpoint of the vibration mode of a plate. In the case of the design for the gearbox housing concerned, the vibration mode which causes the difference in radiation efficiency is not presented. Consequently, the optimum stiffener is placed along the line from the point of excitation to a fixed point, which reduces the vibration deflection of the faces with bearings as well as the in-plane displacement of the bearings.

Dynamic optimization of tracked vehicle power train based on torsional vibration analysis

“…D Richards and DJ Pines 26 used the periodic structures in drivetrains in order to reduce the mesh frequency vibrations and their higher harmonics from being transmitted through structural components in vehicle gearbox. K Inoue et al 27 proposed a method of stiffener layout design to reduce the vibration and structure-borne noise of gear system. YH Guan et al 28 developed an experimental active gearbox structure by applying an improved delayed-x LMS control algorithm based on active shaft transverse vibration control concept.…”

Effect of inner stiffeners on vibration and noise levels of gearbox housing without changing the mass

“…Inoue and Yamanaka investigated the influence of stiffened plate construction to reduce the noise as well as the vibration. In their research, they researched the rib stiffener layout and most effective positions of stiffeners in order to reduce the vibration [11]. Kumar et al tackled with the failure problems of transmission housing or gearbox which were main problems for vehicle manufacturers.…”

H-DGTP—a Heaviside-function based directional growth topology parameterization for design optimization of stiffener layout and height of thin-walled structures

“…Because of their high rigidity-toweight ratio, stiffened plates or shells have been widely used as primary or secondary load bearing components in automotive, aerospace and civil engineering structures (Inoue et al 2002;Afonso et al 2005;Chen et al 2007). Topology optimization has been regarded as the most general type of optimization problems and has been used to improve an initial design by variation of its geometrical and material properties with regards to a set of prescribed objectives and constraints (Sigmund and Maute 2013).…”