Novel 3-D printed aerostatic bearings for the improvement of stability: Theoretical predictions and experimental measurements

Aerostatic bearings are extensively used in the ultra-precision equipment machines. However, vortex phenomenon in the recess will induce micro-vibrations on the bearing surface, which is known to be harmful for manufacturing accuracy and greatly limit the scope of application. According to the formation mechanism of the vortex phenomenon, this paper proposes some novel orifice structures for aerostatic bearings to achieve the purpose of suppressing the vortex occurrence by changing the airflow characteristics in the recess. The theoretical load capacity and pressure vibration of four aerostatic bearings with different orifice structures are obtained by using 3-D computational fluid dynamics (CFD) models. Due to the complexity of the orifice structures, the orifice restrictors are manufactured by 3-D printing technology. Test rigs are built to measure the load capacity, pressure distribution and micro-vibration. And experimental measurement data agrees well with theoretical calculation results. Both the theoretical and experimental results show that the arc hole bearing (AHB) has the best stability and the weakest vibration amplitude, among all the four aerostatic bearings, while the load capacity remains unchanged.