Effect Of Motion Conditions On Single Arc Of Friction Current

The current-carrying friction pair is a friction pair with coupling effect of electrical contact and friction.It is widely used in rail transit,power,communication,automatic control,aerospace and military and other fields.The associated arcs are commonly found in the gap between current-carrying friction pairs.In view of the problem that the associated arc causes serious harm to the sliding current carrying friction pair,the ball(T2 copper)/ plate(T2 copper)sliding current carrying friction pair was used in this project to carry out the single associated arc test of sliding current carrying friction on a self-made single point current carrying friction tester.The influence of motion conditions such as separation speed,contact open circuit voltage and contact speed on sliding current-carrying friction associated single arc and its harm was studied.The results showed that:1.The influence of separation speed on the single associated arc and its harm shows that: The single associated arc can be divided into five stages.With the changing of time,current gradually decreases and voltage gradually increases,finally reaching open circuit voltage.The arc power average value is 5.5 times of the power consumed in sliding contact.The ablation zone of the single arc includes melting zone,splash zone,splash zone and heat affected zone,but the boundaries of melting zone,splash zone and splash zone are unclear,and the ablation zone surface of plate sample tends to be smooth under the condition of small current and single arc.As the separation rate increases,the arc duration of single associated arc does not change much,the maximum arc length gradually increases,the surface smoothness of ablation area increases,and the material damage intensifies.2.The influence of open circuit voltage on the single associated arc and its harm shows that: The voltage of arc shows a decreasing trend with the change of time.And the current of the arc firstly increases,reaches the maximum value,then remains stable,then gradually decreases,and the decreasing speed shows a decreasing trend.The damage to the friction pair is the greatest in the first and middle stages of ablation by the single associated arc.As the open circuit voltage increases,the current carrying efficiency and current carrying stability of the single associated arc show a trend of increasing gradually.The change process of the current in each stage gradually becomes clear.The ablation area,the maximum height difference of the surface profile and the length of the ablation area along the ablation direction caused by the single associated arc gradually increase,thus increasing the ablation degree of the friction pair.3.The influence of contact speed on the single associated arc and its hazards shows that: The voltage changes in four stages and the current changes in six stages.And the change trend of voltage and current with time is consistent with the change trend of open circuit voltage test process.As the contact speed increases,the duration of of the single associated arc decreases first and then stabilizes gradually,and the efficiency increases first and then stabilizes gradually.The length of the ablation area along the arc ablation direction,the area of the ablation area and the fluctuation degree of the surface profile curve of the ablation area all show a decreasing trend,and finally the ablation area smoothly connects with other areas,and the ablation degree of the friction pair by the associated arc is weakened.