摘要 |
A pair of brushes respectively slidably engage radially outer surfaces of first and second electrically conductive rings which are disposed co-axially and are rotatable about their common axis. The first ring surrounds an axial portion of the second ring and is electrically insulated therefrom by a thin layer of insulating material, while the second ring is mounted on a rotary shaft and is electrically insulated therefrom similarly by a thin layer of insulating material. The second ring may be axially stepped so that it has a smaller diameter portion which is surrounded by the first ring and a larger diameter portion which is engaged by the respective brush. |