Rolling brush for electric motor

A dynamo-electric machine comprising:

• a current collector comprising:
• a first plate ring;
• a second plate ring;
• a housing plate, wherein the housing plate is electrically non-conductive;
• a first brush assembly, wherein the first plate ring and the first brush assembly are affixed to a same axial side of the housing plate;
• a second brush assembly, wherein the second plate ring and the second brush assembly are affixed to a same axial side of the housing plate, wherein the first brush assembly and the second brush assembly comprise a plurality of wires, a plurality of springs, a plurality of brush holders, and a plurality of rolling brushes;
• and
• a slip-ring module, wherein the slip-ring module is configured to rotate relative to the housing plate, the first brush assembly, and the second brush assembly about a center axis, wherein the slip-ring module comprises a first slip-ring and a second slip-ring, wherein the plurality of rolling brushes of the first brush assembly and the second brush assembly include rolling contact with respective of the first slip-ring and the second slip-ring as the slip-ring module rotates about the center axis, wherein the plurality of wires, the plurality of brush holders, and the plurality of rolling brushes of the first brush assembly and the second brush assembly are configured to transmit current between respective of the first plate ring and the second plate ring and respective of the first slip-ring and the second slip-ring;
• a rotor, wherein the rotor comprises a shaft and a rotor winding, wherein the slip-ring module is affixed to the shaft, wherein the current collector is configured to supply current to the rotor winding as the rotor rotates about the center axis;
• a stator;
• and
• a motor housing, wherein the motor housing houses the rotor and the stator, wherein the housing plate and the stator are affixed to the motor housing.