Patent ID: 6873078

Claim:
A homopolar machine comprising: a shaft; an armature assembly coupled to the shaft that includes a cylinder having a pair of spaced apart generally radially extending flanges; first and second stators arrays that encircle the armature assembly; a negative bus connected to a first stator; a positive bus connected to a second stator; a first negative brush assembly carried by said first stator for contact with said armature at one location; said brush assembly including brushes, an actuator and a holder designed to effect said contact with said armature; which holder includes (a) radially aligned stem deposed between a pair of parallel flat plates that are mounted in fixed relation to said first stator and (b) a slidable component which carriers a plurality of said first negative brushes and which is slidable between said parallel plates; said stem being formed with a pair of opposed parallel surfaces that are perpendicular to said flat plates, and said slidable component including a pair of flexible heads that engage said opposed stem surfaces; and a second negative brush assembly carried by said armature for contact with said second stator, as a result of their negative charge, the lifetime of said brushes is substantially extended compared to comparable positively charged brushes.