Novelfull‐regionmodel of inherent orifice aerostatic bearings considering air flow in orifice and clearance

Abstract

The performance of inherent orifice‐restricted aerostatic bearings (IORABs) is directly determined by the coupling of air flow in the orifice and clearance. This paper presents a novel full‐region model to analyse the performance of IORABs. The air flowing in the orifice is treated to be adiabatic. The air flow in the pressure depression region of the clearance, which is the key factor influencing the bearing performance, including inertial and viscous terms, is modelled. The Reynolds equation is used to simulate the air flow in the laminar flow region of the clearance. By using this model, the pressure distribution, including the pressure depression characteristics, could be accurately predicted and achieved substantial agreement with the experimental results. The predicted load capacity is accorded well with the published experimental data without relying on the discharge coefficients. The airflow characteristics in the orifice are crucial in determining the bearing performance and directly influenced by the orifice inner surface shape (OISS). Therefore, the pressure distribution and the static characteristics of the bearings with coupling different OISS are also systematically analysed by using this model. Narrowing and widening OISS influence the pressure depression region and the pressure value of the turning point to directly influence the static characteristics of the bearings. The full‐region model and the results are significantly for guiding the precisely calculating and designing the IORABs.

Study on the one-dimensional governing equations of aerostatic circular thrust bearing with a single air supply inlet

“…Therefore, it is crucial to determine the critical velocity or minimum pressure value for different film clearance and supply pressure conditions. Li (2022) obtained the pressure distribution by setting the initial minimum pressure value and its corresponding position in the pressure drop region. The minimum pressure value and the corresponding position are subsequently adjusted by equalizing the mass flow rate for the different flow field regions.…”

“…In the conditions of large film clearance and large supply pressure, the oblique shock wave causes the continuous decrease of pressure. The flow field characteristics of the pressure drop and pressure rise regions are very different from those conditions with small film clearance and small gas supply pressure (Haruyama, 1988;Li, 2022). Therefore, the computing formulas for pressure dropping and pressure rising regions must be derived separately.…”