基于ABAQUS的转子过盈接触及热膨胀分析

Analysis of Interference Contact and Thermal Expansion of the Screw Rotor Based on ABAQUS

螺杆转子是螺杆压缩机的核心部件。对于630机型,采用热套工艺装配后,阴转子曾出现因应力过大而产生断裂的问题,同时过盈配合与热变形共同影响着阴阳转子的间隙。本文采用有限元软件ABAQUS/CAE对630阴转子进行了有限元分析,结果表明阴转子空心齿内的最大应力达到227MPa,同时齿面最薄处的应力达150MPa,易出现疲劳断裂;对阴阳转子在以20~80℃下的非均匀温度场下的热膨胀进行量化,结果表明装配变形量在0.04~0.07mm之间;排端阴阳转子齿顶径向位移达到0.25mm,齿根为0.17mm,建议阴阳转子啮合装配间隙大于0.42mm。

The screw rotor is the key of the screw compressor. For the rotor of 630 adopting shrinkage fit, there was once a fatigue fracture problem of female rotor due to the large stress besides the changing of the assembly clearance. In this paper, an analysis of interference contact and thermal expansion of the screw rotor was taken based on ABAQUS/CAE. The result showed that the maximum stress of the female rotor tooth reached 227 MPa while 150 MPa occurred at the thinnest face where probably broke. For the discharging temperature at 80℃ and assembly temperature/inlet temperature at 20℃, the result showed that the radial displacement due to the interference fit was below 0.1 mm which approximate took up 1/4 of the total displacement which reached 0.25 mm at the tooth tip and 0.17 at the tooth root. So 0.5 mm may be a conservative value for the assembly gap of rotors gearing.