Robust Design of Spiral Groove Journal Bearing 2015-01-9087

Journal bearings are machine elements designed to produce smooth (low friction) motion between solid surfaces in relative motion and to generate a load support for mechanical components. In a Journal bearing, the entire load is carried by a thin film of fluid present between the rotating and the non-rotating elements. The thickness of the film is very sensitive to ambient temperature, radial clearance and misalignment. Though these parameters are difficult to control, it is important to consider these as noises while designing the Journal bearing. When noises in the design space are very strong, the conventional DOE and RSM methods suppress the effect of control factors and render them irrelevant in the design process. This leads to overdesigning the product, which in turn adds more cost.

The main objective of this work is to design a bearing, which is insensitive to noises at each stage of the product life cycle. Parameter design and tolerance design for journal bearing have been carried out using orthogonal array based Taguchi methodology. Optimal levels of the control factors have been found from the factor effect plots for the S/N ratio. It is observed that the Taguchi design shows a reduction of 68% in the Unit Manufacturing Cost (UMC) and about 6 times increase in the average life of the bearing when compared to the baseline design.