Enhancing Lubrication Performance of Water-Lubricated Bearings Using Combined Effects of Herringbone Groove and Porous Bush

To expand effective working speed range of machine tool spindle with the fluid film bearings, this study proposes a novel hybrid porous herringbone groove journal bearing (PHGJB) by integrating herringbone grooves and a porous bush into a water-lubricated bearing. 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.