小孔节流深浅腔动静压气体轴承承载特性分析

以小孔节流深浅腔动静压气体轴承为研究对象,采用Fluent软件对轴承的承载特性进行分析,研究偏心率、供气压力、主轴转速、气膜厚度、浅腔深度比等因素对轴承承载力和刚度的影响。结果表明:小孔节流深浅腔动静压气体轴承浅腔区的平均压力大于深腔区的平均压力,压力最大区域出现在浅腔末端靠近轴承端面处;随着供气压力的增加,承载力逐渐增大,但供气压力不应超过0.95 MPa;当主轴转速在3×10~5 r/min以内时,承载力和刚度随着转速的增加呈线性增长规律,当主轴转速超过3×10~5 r/min继续增加时,承载力和刚度的增长趋势明显放缓;承载力与刚度随着浅腔深度比的增加先增大后减小,当浅腔深度是气膜厚度的1～1.5倍时,承载力与刚度接近最大值。

Analysis on Load Characteristics of Dynamic-Hydrostatic Hybrid Gas Bearings with Orifice Restrictors and Deep-shallow Cavities

Taking the dynamic hydrostatic hybrid gas bearings with orifice restrictors and deep shallow cavities as the research object,the load characteristics were analyzed by Fluent software.The influences of eccentricity,supply pressure,spindle speed,air film thickness and shallow cavity depth ratio on bearing capacity and stiffness were studied.The results show that the average pressure in the shallow cavity of the dynamic hydrostatic hybrid gas bearings with orifice restrictors and deep shallow cavities is greater than that in the deep cavity,and the maximum pressure area occurs at the end of the shallow cavity near the bearing end.With the increase of the supply pressure,the bearing capacity is increased gradually,but the supply pressure should not exceed 0.95 MPa.When the spindle speed is within 3×10.5 r/min,the bearing capacity and stiffness are increased linearly with the increase of spindle speed.When the spindle speed exceeds 3×10.5 r/min,the growth trend of bearing capacity and stiffness slows down obviously.As the shallow cavity depth ratio increases,the bearing capacity and stiffness are increased first and then decreased.When the depth of the shallow cavity is 1 to 1.5 times the thickness of the gas film,the bearing capacity and stiffness are close to the maximum.