Brushroll for vacuum cleaner

Abstract

A brushroll for a vacuum cleaner includes a brush dowel having a plurality of bristles and a drive motor within the brush dowel for rotating the brush dowel in a first direction of rotation, wherein an armature and motor shaft of the drive motor counter-rotates in a second direction of rotation.

What is claimed is: 
     
         1 . A brushroll for a vacuum cleaner, comprising:
 a brush dowel configured to rotate about a longitudinal axis in a first direction;   a plurality of bristles extending outwardly from the brush dowel; and   a drive motor within the brush dowel for rotating the brush dowel about the longitudinal axis, the drive motor comprising:
 a stator mounted to an inner portion of the brush dowel for rotation with the brush dowel about the longitudinal axis; 
 a motor shaft extending within the brush dowel and defining the longitudinal axis; 
 an armature mounted on the motor shaft and rotatable relative to the stator; and 
 a commutator mounted on the motor shaft and rotatable with the armature, relative to the stator; and 
   a mechanical coupling between the drive motor and the dowel comprising a planetary gear assembly;   wherein the armature, commutator, and motor shaft are configured to rotate within the dowel about the longitudinal axis in a second direction, opposite the first direction.   
     
     
         2 . The brushroll of  claim 1 , wherein the stator comprises a plurality of magnets mounted to an interior surface of the brush dowel for rotation with the brush dowel. 
     
     
         3 . The brushroll of  claim 2 , wherein the plurality of magnets comprises at least one pair of opposing magnets, wherein the opposing magnets have opposite polarity. 
     
     
         4 . The brushroll of  claim 2 , wherein the interior surface of the brush dowel comprises a plurality of recesses, and wherein the magnets are received within the recesses. 
     
     
         5 . The brushroll of  claim 4 , wherein the plurality of bristles are offset from the recesses. 
     
     
         6 . The brushroll of  claim 1 , wherein the mechanical coupling is configured to counter-rotate the brush dowel and stator relative to the armature at a first rotational speed less than a second rotation speed of the armature and motor shaft. 
     
     
         7 . The brushroll of  claim 1 , wherein planetary gear assembly reduces the rotational speed of the brush dowel compared to the motor shaft. 
     
     
         8 . The brushroll of  claim 1 , wherein the planetary gear assembly comprises a sun gear mounted on the motor shaft, a ring gear fixed with the brush dowel, and a plurality of planet gears engaged with the sun gear and the ring gear. 
     
     
         9 . The brushroll of  claim 8 , wherein the plurality of planet gears rotate about respective planet gear axes that are fixed in space relative to the brush dowel and the motor shaft. 
     
     
         10 . The brushroll of  claim 8 , wherein the planet gear axes of the plurality of planet gears are parallel to and offset from the longitudinal axis. 
     
     
         11 . The brushroll of  claim 8 , wherein the planetary gear assembly further comprises a carrier for the plurality of planet gears, wherein the carrier is stationary such that the plurality of planet gears rotate in fixed positions while the sun gear and ring gear rotate in opposite directions. 
     
     
         12 . The brushroll of  claim 1 , wherein the drive motor further comprises motor brushes configured to contact the commutator as the commutator rotates. 
     
     
         13 . The brushroll of  claim 12 , wherein the motor brushes are supported by a first bearing holder provided on one end of the brush dowel and mounted to the motor shaft. 
     
     
         14 . The brushroll of  claim 13 , wherein the first bearing holder receives bearings on which the brush dowel rotates relative to the motor shaft. 
     
     
         15 . The brushroll of  claim 13 , and further comprising a second bearing holder provided on an opposite end of the brush dowel and mounted to the motor shaft, wherein the second bearing holder receives bearings on which the brush dowel rotates relative to the motor shaft. 
     
     
         16 . The brushroll of  claim 15 , wherein the planetary gear assembly comprises a plurality of planet gears and a carrier for the plurality of planet gears, and wherein the carrier is integrally formed with or provided on the second bearing holder. 
     
     
         17 . The brushroll of  claim 12 , wherein the commutator comprises a plurality of commutator bars and the armature comprises a plurality of wire slots, wherein the armature is wired so that the wire slots are incrementally advanced ahead of the commutator bars in an advancing pattern. 
     
     
         18 . The brushroll of  claim 17 , wherein the motor brushes are separated by an angular distance relative to the longitudinal axis, and wherein the armature is wired so that the advancing pattern repeats when the brush dowel has rotated a number of degrees equal to the angular distance. 
     
     
         19 . The brushroll of  claim 1 , wherein the planetary gear assembly comprises a −3:1 gear ratio, the stator comprises six field magnets, and the drive motor comprises two motor brushes configured to contact the commutator as the commutator rotates. 
     
     
         20 . A vacuum cleaner comprising:
 a suction nozzle inlet;   a suction source in fluid communication with the suction nozzle inlet for generating a working airstream;   a separating and collection assembly for separating and collecting debris from the working airstream;   a brushroll adjacent the suction nozzle inlet and comprising:
 a brush dowel configured to rotate about a longitudinal axis in a first direction; 
 a plurality of bristles extending outwardly from the brush dowel; and 
 a drive motor within the brush dowel for rotating the brush dowel about the longitudinal axis, the drive motor comprising:
 a stator mounted to an inner portion of the brush dowel for rotation with the brush dowel about the longitudinal axis; 
 a motor shaft extending within the brush dowel and defining the longitudinal axis; 
 an armature mounted on the motor shaft and rotatable relative to the stator; and 
 a commutator mounted on the motor shaft and rotatable with the armature, relative to the stator; and 
 
 a mechanical coupling between the drive motor and the brush dowel comprising a planetary gear assembly; 
 wherein the armature, commutator, and motor shaft are configured to rotate within the brush dowel about the longitudinal axis in a second direction, opposite the first direction.