Patent ID: 7919899

Claim:
An electrical machine, comprising: an armature having armature slots disposed therein; an armature shaft supporting the armature; at least one armature coil received in the armature slots, the at least one armature coil being formed of two partial coils disposed in the armature slots symmetrically to one another relative to an axis of symmetry that passes through a center point of the armature shaft; a commutator having commutator lamination disposed thereon, the partial coils being connected to two adjacent commutator laminations of the commutator; and a first brush, a second brush, and a third brush each resting slidably on the commutator, with the second brush cooperating with the first brush or the third brush, wherein the third brush is disposed relative to the two partial coils in such a way that when electrical contact with the two adjacent commutator laminations is made by third brush, the third brush together with the center point of the armature shaft forms an axis which has an angle, relative to the axis of symmetry of the two partial coils, of from 90°−(180°/number of commutator laminations)−(180°/3·number of commutator laminations) to 90°+(180°/number of commutator laminations)+(180°/3·number of commutator laminations).