热油泵用机械密封波纹管疲劳特性研究

Fatigue Characteristics of Mechanical Seal Bellows for Hot Oil Pumps

热油泵用波纹管机械密封装置的关键零部件金属波纹管,在变工况条件下极易出现疲劳断裂情况。为研究热油泵用机械密封波纹管疲劳特性,建立U形和V形2种类型金属波纹的三维模型,采用结构-热多场耦合分析方法,分析金属波纹管在不同温差工况下的变形场、应力场和疲劳寿命变化规律。结果表明:U形和V形金属波纹管的最大应力值和最大变形量都随着温差的增大而增大,最小疲劳寿命随着温差的增大而减小;V形金属波纹管的力学性能与疲劳性能均好于U形金属波纹管;受力端为整个金属波纹管整体最易损坏部位,该处变形量和应力值都为最大,而疲劳寿命值为最小,为提高金属波纹管的使用寿命和运行稳定性,须对该处进行加固处理。

Metal bellows are the key parts of the bellow mechanical seal device for hot oil pump,which are prone to fatigue fracture under the condition of varying working conditions.Three-dimensional models of U-shaped and V-shaped metal bellows were established to study the fatigue characteristics of mechanical seal bellows for hot oil pumps.The structure-thermal multi-field coupling analysis method was adopted to analyze the deformation field,the stress field and the change law of fatigue life of the two metal bellows under different temperature difference conditions.The results show that the maximum stress and maximum deformation of U-type and V-type metal bellows are increased with the increase of temperature difference,the minimum fatigue life is decreased with the increase of temperature difference.The mechanical and fatigue properties of V-type metal bellows are better than those of U-type metal bellows.The stress end is the most easily damaged part of the whole metal bellows,where the deformation and stress are the largest and the fatigue life value is the smallest,so the strengthening treatment should be carried out to improve the service life and operation stability of the metal bellows.