Patent ID: 6400058
Filing Date: 2002-06-04
Classification: H02K

Abstract:
A universal motor with reduced electromagnetic interference (EMI) characteristics, the universal motor comprisinga stator; rotor comprising a shaft, a commutator mounted on the shaft, and a rotor core mounted on the shaft adjacent to the commutator, the rotor core electrically connected to the commutator, the rotor core rotatably mounted within the stator; brushes for delivering electrical power to the commutator, the brushes elastically contacting the commutator; and a printed circuit board (PCB) comprising a filter circuit for reducing the emission of electromagnetic radiation from the universal motor, the filter circuit electrically connected to the brushes, the PCB mounted over the brushes and over the commutator, substantially covering the brushes and the commutator; wherein when electrical arcing occurs between the commutator and the brushes, the PCB acts as a shield to absorb a portion of the radiation emitted by the arcing so as to reduce the EMI characteristics of the universal motor.