Abstract: In order to solve the problem of low load capacity and static rigidity of a single-hole throttled aerostatic bearing,three cross-sectional forms of throttling grooves,namely triangle,rectangle,and trapezoid,were designed to form a composite throttling method. The gas thrust bearing was taken as the research object to build the gas film characteristic model under the small hole throttle and compound restrictors with different cross-sectional forms of throttling groove. The FLUENT software was used to carry out simulation calculations,to get the bearing capacity,static stiffness and outlet flow rate of the gas thrust bearing.On this basis,the influence of parameters such as the cross-sectional form,cross-sectional area,and gas supply pressure of the throttle groove on the static characteristic of the composite throttling gas thrust bearing was analyzed. The results show that the throttle groove can effectively increase the bearing capacity,static stiffness and outlet flow rate;different cross-sectional form of throttle groove has a different impact on the static characteristic of the bearing,low film thickness trapezoidal cross-section throttle groove shows better bearing capacity,static stiffness and outlet flow rate;within a certain range,as the cross-sectional area increases,the bearing capacity,static stiffness and outlet flow rate show a tendency to increase first and then decrease; the gas supply pressure has a significant impact on the static characteristics of the throttle groove composite throttling gas thrust bearing,as the gas supply pressure increases,the bearing capacity,static stiffness and outlet flow rate continue to increase,but the magnitude gradually of the bearing capacity and static stiffness slows down.

Key words: throttle groove, gas thrust bearing, bearing capacity, static stiffness