A Review on Non-Circular Journal Bearings

Abstract

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.

Transient analysis for offset-elliptical journal bearings under misalignment and dynamic loading

“…However, the circular journal bearings easily suffer from the oil whirl when operating under the condition of misalignment and dynamic loads. 4 The structure of circular journal bearings is relatively simple, and only one oil film can be formed in the working process. This leads to the oil whirl problem may be amplified in the case of misalignment and dynamic loads.…”