Abstract: A rotor assembly for an electric motor, including: a rotor shaft, an armature, wire windings and a commutator, wherein the rotor assembly further includes a ring cap directly connected with the commutator. The ring cap includes chip capacitors soldered on a printed circuit board through a Surface Mount Device (SMD) technique. The ring cap serves as a reservoir for absorption of any noise/sound generated from rotation of the commutator in a DC motor around its brushes. The invention enables compliance with current and future EMC requirements in, for example, the automotive industry.

Abstract: A rotor assembly for an electric motor, including: a rotor shaft, an armature, wire windings and a commutator, wherein the rotor assembly further includes a ring cap directly connected with the commutator. The ring cap includes chip capacitors soldered on a printed circuit board through a Surface Mount Device (SMD) technique. The ring cap serves as a reservoir for absorption of any noise/sound generated from rotation of the commutator in a DC motor around its brushes. The invention enables compliance with current and future EMC requirements in, for example, the automotive industry.