Quiet motorized window treatment system

Abstract

A motorized window treatment system may include a roller tube, a covering material windingly attached to the roller tube, and a drive assembly that may be at least partially disposed within the roller tube. The drive assembly may include a motor having a drive shaft that is elongate along a longitudinal direction and a drive gear attached to the drive shaft such that a toothed portion of the drive gear is cantilevered with respect to the drive shaft. The drive assembly may include a gear assembly having a pair of intermediate gears on opposed sides of the drive gear. Rotation of the drive gear may be transferred through the pair of intermediate gears, a connecting gear, a planetary gear set, a cage, and an idler to the roller tube. Rotation of the roller tube may cause the covering material to move between an open position and a closed position.

1 . A drive assembly comprising:
 a motor having a drive shaft that defines a drive shaft rotational axis, the drive shaft defining a distal end that is spaced from the motor, wherein the drive shaft defines a drive shaft diameter;   a drive gear that engages the distal end of the drive shaft, the drive gear having a toothed portion adapted to rotate about the drive shaft rotational axis, wherein the toothed portion of the drive gear is spaced from the distal end of the drive shaft along the drive shaft rotational axis; and   a gear assembly operatively coupled to the toothed portion of the drive gear such that actuation of the motor causes the drive gear to rotate the gear assembly.   
     
     
         2 . The drive assembly of  claim 1 , wherein the toothed portion of the drive gear defines a root diameter that is less than the drive shaft diameter, and wherein the toothed portion of the drive gear defines a channel that receives the distal end of the drive shaft. 
     
     
         3 . The drive assembly of  claim 1 , wherein the toothed portion comprises less than 12 gear teeth, and wherein the gear teeth are helical. 
     
     
         4 . The drive assembly of  claim 1 , wherein the drive assembly is operatively coupled to a roller tube for rotating the roller tube about a longitudinal axis defined by the roller tube. 
     
     
         5 . The drive assembly of  claim 4 , wherein the drive shaft extends parallel to the longitudinal axis of the roller tube. 
     
     
         6 . The drive assembly of  claim 1 , wherein the distal end of the drive shaft is spaced from the motor by a first distance and the toothed portion is spaced from the motor by a second distance that is greater than the first distance. 
     
     
         7 . The drive assembly of  claim 1 , wherein the toothed portion is comprised of plastic and the drive gear further comprises a coupling portion that extends from the toothed portion and mates with the drive shaft so as to operatively couple the drive gear to the drive shaft, the coupling portion comprising a non-plastic portion that operatively couples the toothed portion to the coupling portion. 
     
     
         8 . The drive assembly of  claim 1 , wherein the gear assembly comprises a pair of intermediate gears disposed on opposed sides of the toothed portion of the drive gear, a planetary gear set that is operatively coupled to the roller tube, and a connecting gear that is operatively coupled to the pair of intermediate gears. 
     
     
         9 . The drive assembly of  claim 8 , wherein the gear assembly further comprises a cage that rotatably captures one or more shafts of the planetary gear set such that rotation of the planetary gear set causes the cage to rotate, and wherein the cage is connected to the roller tube via an idler such that rotation of the cage causes the roller tube to rotate about the longitudinal axis. 
     
     
         10 . The drive assembly of  claim 1 , wherein the gear assembly is operably coupled to the roller tube such that actuation of the motor causes the roller tube to rotate about the longitudinal axis. 
     
     
         11 . A motorized window treatment system comprising:
 an elongate roller tube defining a longitudinal axis;   a covering material windingly attached to the roller tube;   a drive assembly that is operatively coupled to the roller tube for rotating the roller tube about the longitudinal axis, the drive assembly including:
 a motor having a drive shaft that defines a drive shaft rotational axis, the drive shaft defining a distal end that is spaced from the motor, wherein the drive shaft defines a drive shaft diameter; 
 a drive gear that engages the distal end of the drive shaft, the drive gear having a toothed portion adapted to rotate about the drive shaft rotational axis, wherein the toothed portion of the drive gear is spaced from the distal end of the drive shaft along the drive shaft rotational axis; and 
 a gear assembly operatively coupled to the toothed portion of the drive gear such that actuation of the motor causes the gear assembly to rotate. 
   
     
     
         12 . The motorized window treatment system of  claim 11 , wherein the toothed portion defines a root diameter that is less than the drive shaft diameter. 
     
     
         13 . The motorized window treatment system of  claim 11 , wherein the toothed portion of the drive gear comprises a plurality of gear teeth that are helical gear teeth. 
     
     
         14 . The motorized window treatment system of  claim 11 , wherein the distal end of the drive shaft that is spaced a first distance from the motor, and wherein the toothed portion of the drive gear is spaced a second distance from the motor, and wherein the second distance is greater than the first distance. 
     
     
         15 . The motorized window treatment system of  claim 11 , wherein the drive gear is cantilevered with respect to the distal end of the drive shaft, and wherein the drive gear defines a channel that receives a portion of the drive shaft. 
     
     
         16 . The motorized window treatment system of  claim 11 , wherein the drive gear further comprises a coupling portion that extends from the toothed portion and mates with the drive shaft so as to operatively couple the drive gear to the drive shaft, the coupling portion comprising a non-plastic portion that operatively couples the toothed portion to the coupling portion. 
     
     
         17 . The motorized window treatment system of  claim 11 , wherein the gear assembly is configured to be operatively coupled to the roller tube such that actuation of the motor causes the roller tube to move the covering material between an open position and a closed position. 
     
     
         18 . The motorized window treatment system of  claim 11 , wherein the covering material is a screen. 
     
     
         19 . The motorized window treatment system of  claim 11 , wherein the gear assembly comprises a pair of intermediate gears disposed on opposed sides of the toothed portion of the drive gear, a planetary gear set that is operatively coupled to the roller tube, and a connecting gear that is operatively coupled to the pair of intermediate gears. 
     
     
         20 . The motorized window treatment system of  claim 19 , wherein the gear assembly further comprises a cage that rotatably captures one or more shafts of the planetary gear set such that rotation of the planetary gear set causes the cage to rotate, and wherein the cage is connected to the roller tube via an idler such that rotation of the cage causes the roller tube to rotate about the longitudinal axis.