In order to meet the requirements of condition monitoring of oil system component deterioration at an early stage

an oil-line debris electrostatic sensor has been used to investigate real time and in-line wear monitoring in oil lubricated sliding contacts of bearing steel.The charging mechanism of oil lubricated metallic debris was researched and electrostatic monitoring system was designed.The wear experiments were divided into different loads and speeds

and then the friction coefficient

oil-line debris electrostatic signal

and electrostatic signal root mean square (RMS) were obtained and correlatively analyzed.The results show:(1) the oil-line debris electrostatic method and friction coefficient can consistently detect adhesive wear;(2) the electrostatic monitoring method can detect the abnormal signal before adhesion;(3) in the normal wear stage

the friction coefficient increases with the load reduction

and reduces with the speed increase;(4) in the severe wear stage

the RMS of electrostatic signal pulse peak first increase

and then reduces with the load increase

and reduces with the speed increase.