接触压力对导电滑环/碳刷滑动电接触信号传输波形失真的影响

The Impact of Load on Waveform Distortion in the Signal Transmission of the Ring-Brush Sliding Electrical Contacts

针对导电滑环/碳刷(简称环刷)滑动机构与固定机构之间电能和电信号传输的关键装置,通过自主设计环刷滑动电接触正弦信号传输试验机,研究不同接触压力下环刷滑动电接触信号传输过程波形失真规律.结果显示:信号波形失真随环刷滑动次数的增加而增大,随接触压力的增加而减小,增大接触压力可抑制电信号波形失真;通过环刷接触面SEM与XPS分析发现,信号波形失真主要由环刷界面摩擦膜引起,摩擦膜附加的膜电阻造成环刷接触电阻增大,同时环刷滑动电接触过程摩擦温度逐渐升高,摩擦膜氧化铜含量逐渐增加导致摩擦膜电阻增大,所以摩擦膜是引起接触电阻和摩擦系数变化的主要原因.

Addressing the key device for the transmission of electrical energy and signals between the sliding and fixed mechanisms of the conductive slip ring and carbon brush(referred to as the ring brush),this study investigates the distortion pattern of waveforms in the signal transmission process of ring brush sliding electrical contact under different loads.Through the independently designed experimental device for transmitting sinusoidal signals of ring-brush sliding electrical contact,the results show that signal waveform distortion increases with the number of ring-brush slides and decreases with the increase of contact pressure.Increasing the contact pressure can suppress the distortion of electrical signal waveforms.Furthermore,analysis of the ring brush contact surface using SEM and XPS reveals that signal waveform distortion is mainly caused by the friction film at the ring brush interface.The additional film resistance from the friction film leads to an increase in the contact resistance of the ring brush.At the same time,the friction temperature during the sliding electrical contact process gradually rises,and the content of oxidized copper in the friction film increases,leading to a larger film resistance.Therefore,the friction film is the primary cause of changes in contact resistance and friction coefficient.