Enhancing Lubrication Performance of Fluid Film Journal Bearings Using Combined Effects of Herringbone Groove and Porous Bush

Abstract

This study investigates a method combining a porous bush and herringbone groove to extend the effective working speed range of conventional fluid film journal bearings for machine tool spindles. A novel bearing, termed the porous herringbone groove journal bearing (PHGJB), is proposed. However, existing literature lacks a model that accurately describes the lubrication behavior of the PHGJB. To address this gap, this paper presents a lubrication model for the PHGJB that incorporates velocity slip, angular misalignment, and turbulence effects. This model employs the boundary-fitted coordinate system and finite control volume methods to address the challenges posed by the herringbone grooves and three-dimensional flow within the porous bush. The performances of the PHGJB, a typical hydrodynamic herringbone groove journal bearing (HGJB), and a hydrostatic porous plain journal bearing (PPJB) are compared. Differences between the calculated results from the one- and three-dimensional flow models for the flow within the porous bush are also analyzed. Results show that the PHGJB significantly improves stiffness at low speeds, while enhancing stability and controlling temperature rise at high speeds compared to the HGJB and PPJB. Consequently, it offers a broader operating speed range. The proposed model offers an effective tool for structural design and performance analysis of PHGJBs.