A Review on Non-Circular Journal Bearings

Hydrodynamic bearings depend on the high journal speed to move the pressurized fluid in a wedge between the faces. Instabilities due to oil whip and whirl are usually observed when using hydrodynamic circular journal bearing in high speed rotating machinery. To overcome these difficulties, non-circular bearings are usually preferred over circular bearings. A non-circular journal bearing has increased shaft stability, increased oil flow and reduced power losses as compared to circular journal bearing under proper working conditions. This paper deals with a review of major works conducted on non-circular bearings to improve the performance characteristics. The effect of incorporating pressure dams in bearings, use of porous bearing, use of non-Newtonian lubricants and micropolar lubricants on the static and dynamic characteristics of the bearing have also been analyzed.