abstract |
In this commutator, a metal riser piece is attached on a resin base, and a segment comprising a metal layer and a carbon layer is joined to the riser piece. The metal layer contains brass, tin and 0-5 mass% of carbon (exclusive of 5), and does not contain copper powder, and the metal layer is joined to the riser piece by soldering without a coating layer on the surface thereof. The segment can be joined to the riser piece without a coating layer. |