Abstract:The mathematical model for the lubrication analysis of spherical spiral grooved hybrid gas bearings was established.Through the establishment of the generalized coordinate and conformal mapping,the model was simplified.By generalized helical coordinate transformation,the solving domain spherical grid was divided,and numercial calculation accuracy was improved.Reynolds equation was discretized by the finite difference method.The differential expression of Reynolds equation was established.The three dimensional (3D) micro steady state gas film pressure distribution and film thickness distribution was calculated by the VC++60 software.The steady state bearing capacity was obtained by the integration of the micro gas film circumferential and radial pressure.Dynamic pressure and static pressure coupling effect was researched.The influence of the spiral groove structure parameters and the number of the orifice variations to bearing capacity was analyzed.The result shows that the effect of static pressure is increased notably with the increasing of the number of small holes,as well as of the bearing capacity.Along with the increasing of spiral angle,trough depth rate,trough width ratio,the bearing capacity is all increased first and then decreased,indicating that optimization of gas bearing design parameters can improve the lubrication performance of gas and bearing capacity.
