EMI suppression in permanent magnet DC motors having PCB outside motor in connector and overmolded

Abstract

A permanent magnet DC motor 10 having electro-magnetic interference (EMI) suppression includes a metal motor housing 12 and a brush card assembly 34. The brush card assembly includes brushes 20 and leads 24 constructed and arranged to be coupled with a source of power to power the motor. A brush card housing 14 has a first portion 18 housing the brushes and a second portion 22, integral with the first portion, and housing the leads. A printed circuit board 26 is mounted with respect to the second portion of the housing and carries at least one electro-magnetic interference (EMI) suppression component 30 constructed and arranged to suppress EMI generated by the motor. The leads are electrically connected to the printed circuit board so that current can be provided through the printed circuit board to the brushes. A contact member 40 is electrically connected between the printed circuit board and the metal motor housing so that the at least one EMI suppression component couples the brushes to the metal motor housing thereby causing the metal motor housing to become an AC ground and EMI shield.

1 . A connector structure of a permanent magnet DC motor, the motor having brushes and a motor housing, the connector structure comprising: 
 a connector body constructed and arranged to be disposed outside of the motor housing,    leads housed by the connector body and being constructed and arranged to be connected to a source of power to power the motor, and    at least one electro-magnetic interference (EMI) suppression component electrically connected with the leads and constructed and arranged to suppress EMI generated by the motor, the leads being constructed and arranged so that current can be provided through the leads to the brushes,    wherein the connector body includes plastic material covering the at least one EMI component and at least a portion of the leads, with a surface defined by the plastic material being completely exposed to atmosphere.    
   
   
       2 . The connector structure of  claim 1 , wherein the at least one EMI suppression component is electrically connected to the leads via a printed circuit board and a surface of the circuit board being covered by the plastic material.  
   
   
       3 . The connector structure of  claim 1 , wherein the at least one EMI suppression component includes a capacitor.  
   
   
       4 . The connector structure of  claim 2 , wherein the leads include ends that are soldered to the printed circuit board.  
   
   
       5 . canceled  
   
   
       6 . canceled  
   
   
       7 . canceled  
   
   
       8 . canceled  
   
   
       9 . A brush assembly for a permanent magnet DC motor having electro-magnetic interference (EMI) suppression, the brush assembly including: 
 brushes,    leads constructed and arranged to be coupled with a source of power to power the motor,    a housing having a first portion housing the brushes, and a second portion integral with the first portion and housing the leads, and    at least one electro-magnetic interference (EMI) suppression component electrically connected with the leads and constructed and arranged to suppress EMI generated by the motor, the leads being constructed and arranged so that current can be provided through the leads to the brushes,    wherein the connector body includes plastic material covering the at least one EMI component and at least a portion of the leads, with a surface defined by plastic material being completely exposed to atmosphere.    
   
   
       10 . The motor of  claim 9 , wherein the at least one EMI suppression component is electrically connected to the leads via a printed circuit board and a surface of the circuit board being covered by the plastic material.  
   
   
       11 . The motor of  claim 9 , wherein the at least one EMI suppression component includes a capacitor.  
   
   
       12 . The motor of  claim 10 , wherein the leads include ends that are soldered to the printed circuit board.  
   
   
       13 . canceled  
   
   
       14 . canceled  
   
   
       15 . canceled  
   
   
       16 . canceled  
   
   
       17 . canceled