Analysis of a Hydrodynamic Herringbone Grooved Journal Bearing Considering Cavitation

Abstract

The Reynolds equation, incorporating Elrod’s cavitaton algorithm, is discretized on a rectangular grid in computational space through coordinate mapping in order to accurately analyze a herringbone grooved journal bearing of a spindle motor in a computer hard disk drive. The pressure distribution and cavitation area are determined by using the finite volume method. Predicted results are compared to experimental data of previous researchers. It was found that positive pressure is developed within the converging section of the bearing and that a cavity occurs in the diverging section. Cavitation has been neglected in the previous analyses of the herringbone grooved bearing. Load capacity and bearing torque are increased due to the increase of eccentricity and L/D and the decrease of the groove width ratio. The maximum load capacity was found to occur at a groove angle of 30 degrees while bearing torque remains constant due to the variation of the groove angle. The cavitation region is significantly decreased with the inclusion of herringbone grooves. However, the region increases with the increase of the eccentricity, L/D, groove angle and the rotational speed and the decrease of the groove width ratio. [S0742-4787(00)01401-6]