Development of aerostatic rotary table for micro-gravity test based on porous bronze

For the simulation of micro-gravity environment, in order to reduce the vortex interference torque, an aerostatic rotary table system based on porous bronze was designed. First, in the selection of thrust air bearing, the local porous restrictor and full porous restrictor were compared. It was found that at gas film thickness of 20 μm, the load capacity of full porous restrictor was 40% higher than that of local porous restrictor, and thus the full porous restrictor was selected for thrust bearing design. Then, the load capacity and stiffness characteristics of thrust bearing and journal bearing of aerostatic rotary table under different air supply pressure and different material permeability were analyzed. Results showed that when the material permeability was smaller, the gas film stiffness was higher, which provides basis for the structural design of the aerostatic rotary table. Finally, the open-type thrust bearing was adopted in the aerostatic rotary table, and the restrictor was made of self-developed porous bronze material. By precision machining, the permeability was remained approximately unchanged. The rotary accuracy of the trial produced aerostatic rotary table was less than 0.8 μm. There was no self-excited vibration under 150 kg load. The maximum disturbance torque of the developed aerostatic rotary table system was 9 × 10-4 N ∙ m. The proposed aerostatic rotary table can be used not only in the field of micro-gravity tests, but also in the fields such as ultra-precision machining. © 2023 Harbin Institute of Technology. All rights reserved.