小型低温风洞压缩机转子结构设计

Structural design of a small cryogenic wind tunnel compressor rotor

低温风洞的轴流压缩机是整个风洞的动力装置,具有温度范围宽广、运转速度较高等特点。本文围绕低温压缩机的转子结构设计,论述了压缩机主轴-轮毂连接、轮毂-叶片连接、轴承的选取、轴承的润滑、密封结构形式以及轴系热防护方案等关键技术,针对弹性支承下的转子动力学校核以及转子热应力计算等内容开展了仿真研究。计算结果表明,转子第一阶临界转速远高于最大转速,降温结束时推力轴承座圆锥面内侧的最大应力值约170MPa,安全系数大于1.5。压缩机组和小型低温风洞进行了联合调试,当总温降至110K时,轴承温度大于5℃,轴承振动在全转速范围内小于3mm/s。各项性能指标均满足使用要求,调试结果验证了该压缩机转子系统设计的可靠性。

The axial compressor is the power equipment of the cryogenic wind tunnel.It has the characteristics of the wide temperature range and high speed of operation.The compressor rotor structural design was studied in this paper.Key technologies of the compressor design were discussed in detail,including shaft-hub connection,hub-blade connection,bearing selection,lubrication method,seal structure,heat protection scheme,et al.The compressor rotor dynamical characteristics under elastic supporting was calculated using the FEM method.The thermal-structure coupling simulation of the rotor was conducted.Calculation results show that the rotor critical speed is much higher than the maximum speed,the maximum stress value of the thrust bearing housing is about 170 MPa when the temperature dropping stage ends,and the safety factor is bigger than 1.5.United debugging of the compressor on a small cryogenic wind tunnel was carried out.Experimental results show that when the total temperature of the wind tunnel drops to110 K,the bearing temperature is higher than 5℃,and the bearing vibration value is lower than3 mm/s.They both meet the design requirement,which verifies that this compressor rotor design is reliable.