Abstract: WK20 excavator is a semiclosed space because the highvoltage collecting ring of the inlet line is between the rotating upper and lower platforms.In addition,the lubricating oil of the rotary ring is thrown into the highvoltage collecting ring when it is working,which causes hidden trouble to the safety of the equipment,at the same time,the platform and the ring rail are worn,which reduces the elastic space of the collector ring shoe and adversely affects the safety and service life of the ring.In order to solve the hidden trouble of the equipment and increase the service life of the ring,the scheme of installing the highvoltage collector ring in the upper platform and the lowvoltage collector ring together was worked out.Through the improvement,the hidden trouble of the equipment safety is eliminated,the service life of the ring track is increased,which is of great significance to the company′s equipment safety management and cost management.

Key words: Excavator,Rail,Collector ring,Drive