基于有限元的分子泵高速轴系优化设计

Optimization design of high-speed shafting for molecular pump based on finite-element method

分析了复合式脂润滑分子泵高速轴系的力学性能,进行了分子泵高速轴系优化设计。本文以CG-250/1600型复合分子泵作为原型,优化改进了轴承支承跨距和轴系刚度,采用有限元法对比分析计算了高速轴系优化设计前后的动静态力学性能,得到转子系统工作转速内的所有临界转速和模态阵型,并对两种结构进行了试验验证。结果表明:试验结果和理论分析基本一致。优化后,转子系统临界转速小幅变化,幅频特性基本不变,启停过程更平稳,初始不平衡响应振幅明显下降,减小了共振带来的安全隐患,同时极大地降低了转子系统动平衡的调试难度。

The mechanical performance of the high-speed shafting of compound and greased molecular pump was analyzed, and thus the design optimization was carried out. In this paper, the CG-250/1600 pump was used as the prototype, and the bearing span and shaft stiffness were optimized and improved. The dynamic and static mechanical properties of the high-speed shaft were calculated before and after optimization design of the high-speed shafting. All the critical speed and mode formation of the rotor system were obtained, and two kinds of structures were tested and verified. The results show that the experimental results are basically the same as the theoretical analysis. After optimization, the critical speed of the rotor system varied slightly;the amplitude-frequency characteristic was basically unchanged;the start and stop process was more stable;the initial unbalance response decreased obviously,the hidden danger caused by the resonance was reduced, and the difficulty of the dynamic balancing debugging was reduced greatly.