磨损产物对载流摩擦界面放电的影响  

Influence of Wear Products on Current-Carrying FrictionInterface Discharge

作　　者：肖水淋 李晨诗 赵新泽 李雪强 陈明 XIAO Shuilin;LI Chenshi;ZHAO Xinze;LI Xueqiang;CHEN Ming(School of Mechanical and Power Engineering,Three Gorges University,Yichang Hubei 443002,China)

机构地区：[1]三峡大学机械与动力学院,湖北宜昌443002

出　　处：《润滑与密封》2024年第11期116-124,共9页Lubrication Engineering

基　　金：国家自然科学基金项目(52475202)。

摘　　要：水轮发电机碳刷/集电环运行过程中接触界面产生的磨损微粒介入碳刷/集电环偏心摆振产生的瞬时间隙中时,会影响界面放电产生打火烧蚀的现象。为研究磨损微粒对碳刷/集电环接触界面影响,以D172碳刷与集电环常用材料45钢为摩擦副,设计不同磨损微粒覆盖率、不同种类磨损微粒覆盖的摩擦界面,通过正负极性下放电试验,观测界面产生电火花规律及对集电环表面损伤影响。结果表明:界面电火花相对强度随着界面磨损微粒覆盖率的增大而增强,且电火花主要集中出现在磨损微粒区域;电火花特性与磨损微粒种类相关,界面为碳粉、铁粉磨损微粒时,碳粉微粒下放电火花形状为长条与点状的集合,且正负极火花强度差异不明显,放电位置在接触面,而铁粉微粒下放电火花则呈喷射球/椭球状,放电位置偏离,飞溅现象明显。When the wear particles generated at the contact interface of the carbon brush/collector ring during the operation of the hydroelectric generator enter the instantaneous gap caused by the eccentric oscillation of the carbon brush/collector ring,it will affect the interface discharge and cause spark erosion.To investigate the influence of wear particles on the contact interface of the carbon brush/collector ring,using D172 carbon brush and 45 steel commonly used material of collector ring as the friction pair,the friction interfaces with different wear particle coverage rates and coated with different types of wear particles were designed.The discharge tests under positive and negative polarities were carried out to observe the pattern of electric sparks generated at the interface and the impact on the surface damage of the collector ring.The results show that the relative strength of interface electric sparks increases with the increase of interface wear particle coverage,and electric sparks mainly appear in the wear particle area.The characteristics of electric sparks are related to the types of wear particles.When the interface is composed of carbon powder and iron powder wear particles,the shape of the discharge spark under the carbon powder particles is a combination of long bars and dots,the difference of spark strength at positive and negative polarities is not significant,and the discharge position is at the contact surface.The discharge spark under the iron powder particles is in the shape of a spray ball/ellipsoid,with deviation in discharge position and obvious splashing phenomenon.

关 键 词：碳刷/集电环 磨损微粒 载流摩擦界面 打火烧蚀 放电特性 

分 类 号：TH117.1[机械工程—机械设计及理论]