Brushgear for radial face slip-rings on motor vehicle generator - is mounted in caliper fashion to give equal brush pressure on both rings

The slip-ring units comprises two rings (15), axially in line, with radial contact surfaces facing in opposite directions. The rings are typically mounted on a disc and bush (14,13) of insulation material which fits on the end of the generator shaft (11). The brushes (18) run on the radial faces. They are mounted on a caliper type holder having carrying arms (19) of equal length and a spring (21) in tension giving the required brush pressure. The arrangement gives equal pressure between both brushes and their respective slip-rings. The radial face contact eliminates any effects of shaft eccentricity. Both these features combine to give smooth running and long brush life.