带轴头机械密封改进性设计

Improved Design of Mechanical Seal with Shaft Head

针对某型带延长轴头变压力机械密封存在安装失准导致机封工作不稳定、泄漏量超标问题,基于机封变压力、介质含泥沙环境等实际工况,结合机封结构设计,对故障机理进行分析,探讨机封内部结构设计、与轴配合接口设计对密封性能的影响。分析结果表明,在泵轴添加延长轴头的情况下,需要兼顾考虑轴头安装后随轴的跳动量以及实际工程施工中轴头的可安装、可拆卸因素。经改进设计后,新型结构满足机械密封密封性要求、轴头(尾端安装叶轮)的跳动要求,实现了轴头拆装便利。

For a certain type of mechanical seal with extended shaft head variable pressure,there is a problem of unstable seal work and excessive leakage due to mis-installation,based on the actual working conditions such as variable pressure of the seal and media containing sediment environment,combined with the structural design of the seal,the failure mechanism is analyzed,and the influence of the internal structure design of the seal and the design of the interface with the shaft on the seal performance is explored.The results of the analysis show that,in the case of adding an extended shaft head to the pump shaft,it is necessary to take into account the amount of runout of the shaft head after installation as well as the installable and removable factors of the shaft head in actual engineering construction.The new structure meets the requirements of mechanical seal tightness and runout of the shaft head(impeller installed at the end),and facilitates the disassembly and installation of the shaft head after the retrofit design.