火电厂凝结水泵轴系断裂分析

Analysis Shaft Fracture of Condensate Pump in Thermal Power Plant

针对某立式恒速凝结水泵在运行中发生突发性泵轴断裂,通过对损坏的水泵泵轴各部位进行测量,核算水泵各运行状态下泵轴的扭转应力、拉应力强度。分析得出水泵轴系断裂的原因,主要是泵的上/下轴与联轴器径向配合设计为间隙配合,导致泵轴倒角加工部位出现应力集中。通过对凝结水泵轴系扭矩传递的分析提出:应将该配合设计为适当的过盈配合,避免泵的上下轴连接部位出现轴向和周向相对位移而导致泵轴断裂。

In allusion to the problem of sudden shaft fracture of one vertical type constant speed condensate pump in opera- tion, each parts of the damaged pump shaft were measured, torsion stress and tensile stress intensity of the pump shaft were both accounted under various running states of the pump. Therefore, this paper analyzes reasons for fracture of the shaft and considers the main reason is radialclearance coordination between the up and down shafts of pump and the coupling, which causes stress concentration in the chamfering part of pump shaft. Based on analysis for torque transmission, it proposes the fit should be designed for appropriateinterference fit so as to avoid the pump shaft fracture caused by movement of the upper and lower shaft connecting position in the straight direction and the circumferential direction.