Power transmission with bead drive

Abstract

A power transmission is provided. The power transmission includes a housing including a continuous channel following a three-dimensional path. A plurality of beads is located within the continuous channel and movable therein. A first sprocket is rotatably connected to the housing and forms a first portion of the continuous channel in movable contact with the plurality of beads. A second sprocket is rotatably connected to the housing and forms a second portion of the continuous channel in movable contact with the plurality of beads, the second sprocket having an axis of rotation angled with respect to an axis of rotation of the first sprocket. A milling tool and a method of removing material from a work piece are also provided.

1 . A power transmission comprising: 
 a housing including a continuous channel;    a plurality of beads located within the channel and movable therein;    a first sprocket rotatably connected to the housing and forming a portion of the continuous channel in movable contact with the plurality of beads; and    a second sprocket rotatably connected to the housing and forming another portion of the continuous channel in movable contact with the plurality of beads;    wherein a portion of the housing comprising the channel comprises at least one open section in an area adjacent to at least one of the first sprocket and the second sprocket to permit engagement of the at least one of the first sprocket and the second sprocket with the plurality of beads, and wherein the at least one open section has a width smaller than a width of the plurality of beads, for retaining the plurality of beads along a bead path within the housing in the continuous channel.    
   
   
       2 . The power transmission of  claim 1 , wherein the housing comprises extending portions, the extending portions defining the at least one open section in at least a transition area where the plurality of beads begin to engage the at least one of the first sprocket and the second sprocket.  
   
   
       3 . The power transmission of  claim 1 , wherein: 
 the continuous channel follows a three-dimensional path; and    the second sprocket has an axis of rotation angled with respect to an axis of rotation of the first sprocket.    
   
   
       4 . The power transmission of  claim 1 , wherein the plurality of beads are substantially spherical, whereby the at least one open section has a width smaller than a diameter of the plurality of beads.  
   
   
       5 . The power transmission of  claim 1 , wherein the plurality of beads are aligned in single file within the continuous channel.  
   
   
       6 . The power transmission of  claim 1 , wherein each of the plurality of beads is at least one of in contact with and in close proximity to an adjacent one of the plurality of beads, and wherein the continuous channel is substantially entirely filled with beads.  
   
   
       7 . The power transmission of  claim 1 , wherein the plurality of beads are substantially spherical and aligned in single file within the continuous channel, the transmission further comprising at least one separator between at least two of the plurality of beads for maintaining a desired distance between the at least two of the plurality of beads.  
   
   
       8 . The power transmission of  claim 1 , wherein at least one of the first and second sprockets comprises a plurality of cups at a periphery thereof, and the plurality of beads partially extend through the open section and removably contact the plurality of cups.  
   
   
       9 . The power transmission of  claim 1 , wherein at least one of the first and second sprockets comprises a plurality of cups at a periphery thereof, and the plurality of beads partially extend through the open section and removably contact the plurality of cups, wherein each of the plurality of cups comprises a spherical contact surface.  
   
   
       10 . The power transmission of  claim 1 , wherein at least one of the first and the second sprockets comprises an outwardly extending integrally formed shaft.  
   
   
       11 . The power transmission of  claim 1 , wherein at least one of the first and the second sprockets comprises a keyed aperture for removably receiving a keyed shaft.  
   
   
       12 . The power transmission of  claim 1 , further comprising at least one cooling passage within the housing for passing a flow of cooling fluid.  
   
   
       13 . The power transmission of  claim 1 , wherein the continuous channel comprises a machined channel disposed within the housing.  
   
   
       14 . The power transmission of  claim 1 , further comprising a third sprocket rotatably connected to the housing in movable contact with the plurality of beads.  
   
   
       15 . The power transmission of  claim 1 , wherein the beads are sized between about 3/32 inch and ¼ inch.  
   
   
       16 . The power transmission of  claim 1 , wherein the housing comprises: 
 a first body with at least a first part of the continuous channel formed therein; and    a second body with at least a second part of the continuous channel formed therein connected to the first body, wherein the second part is adjacent to the first part along a length of the continuous channel;    wherein the first body comprises at least a first channel forming portion, and the second body comprises at least a second channel forming portion opposing the first channel forming portion, wherein the first channel forming portion and the second channel forming portion together define the at least one open section.    
   
   
       17 . The power transmission of  claim 1 , wherein the plurality of beads are substantially spherical, whereby the at least one open section has a width smaller than a diameter of the plurality of beads, and wherein at least a portion of the continuous channel is at least partially contoured to a perimeter of the plurality of beads.  
   
   
       18 . The power transmission of  claim 1 , wherein at least one of the first sprocket and the second sprocket is adjustable relative to the housing for adjusting an effective width of the continuous channel adjacent to the at least one of the first sprocket and the second sprocket.  
   
   
       19 . The power transmission of  claim 1 , wherein at least one of the first sprocket and the second sprocket comprises a plurality of cups formed on a peripheral corner of the at least one of the first sprocket and the second sprocket, and wherein the plurality of beads partially extend through the open section and removably contact the plurality of cups at the peripheral corner.  
   
   
       20 . A method of transferring mechanical power comprising: 
 providing a power transmission comprising: 
 a housing including a continuous channel;  
 a plurality of beads located within the channel and movable therein;  
 a first sprocket rotatably connected to the housing and forming a portion of the continuous channel in movable contact with the plurality of beads; and  
 a second sprocket rotatably connected to the housing and forming another portion of the continuous channel in movable contact with the plurality of beads;  
 wherein a portion of the housing comprising the channel comprises at least one open section in an area adjacent to at least one of the first sprocket and the second sprocket to permit engagement of the at least one of the first sprocket and the second sprocket with the plurality of beads, and wherein the at least one open section has a width smaller than a width of the plurality of beads, for retaining the plurality of beads along a bead path within the housing in the continuous channel;  
   connecting the first sprocket to at least one device; and    rotating the second sprocket, whereby the at least one device is actuated.