螺杆真空泵转子-泵腔系统热变形分析

Thermal Deformation of Rotors and Casing in Operation of Screw Vacuum-Pump

以等螺距螺杆真空泵为研究对象,对工作状态下泵腔内各点间隙变化进行研究。建立了工作状态下主动、从动转子和泵腔温度场有限元模型,通过分析得到转子-泵腔系统的温度场和热变形分布情况,并绘制了工作状态下泵腔内各点间隙变化的曲线图。研究结果表明：转子轴向存在较大温差,泵腔相对于转子温度较低。工作状态下泵腔内各处间隙存在较大差异。进气端间隙较大,各点间隙在0.23~0.3mm之间;排气端间隙较小,各点间隙在0.11至0.15mm之间。

The temperature field in a screw vacuum pump and the thermal deformation of the rotors and casing in the dynamic operation mode were empirically simplified, mathematically modeled, theoretically analyzed, and numerically sim- ulated in finite element method. The influence of the geometries of the pump parts, including the male and female rotors, casing and clearances, on the temperature distributions and variations in gap widths because of thermal deformation was investigated. The simulated results show that fairly large temperature gradients exist in the axial direction of the rotors,in the easing,and at the gaps. The rotors are hotter than the casing;and the gap widths changes because of thermal deforma- tion. For example, the non-uniform gap-widthsnear the inlet （around 0.23 - 0.30 mm） are wider than those near the hot- ter outlet （about 0.11 - 0.15 mm）. We suggest that the simulated results be of some technological interest in adjusting the clearances of the screw vacuum pump.