The working principle of the trolley line is: due to the needs of production, the mobile device needs to move its position from time to time. At each different position, the mobile device needs to be able to obtain the power supply and the signal source that requires the mobile device to operate at any time, otherwise it cannot Continuous movement. At this time, a number of conductors were laid in parallel along the running track of the mobile equipment, and the mobile equipment was equipped with a collector that can take electricity from the conductor, and the brush on the collector was adjusted by the pressure device. Contact for best condition. The trolley line needs to be maintained regularly in the later stage, remove the debris attached to the trolley line, check whether the connection part of the trolley line is loose, replace the worn collector brush, check the parallelism of the trolley line with the track, Keep the trolley line parallel to the track at all times.