Crawler Traction Device

Abstract

A crawler traction device for a crawler vehicle, in particular a tractor, the device having a carriage, a drive sprocket rotating about a first axis, an idler wheel rotating about a second axis parallel to the first axis. The track is looped about the drive sprocket and the idler wheel and meshes with the drive sprocket along a meshing arc. The traction device has a noise and vibration damping device having an auxiliary roller which rotates about a third axis parallel to the first axis and is eccentric with respect to the drive sprocket as well as smaller in diameter than the drive sprocket. The noise and vibration damping device only cooperates with the track along a portion of the track located, in use, immediately upstream from the meshing arc and interposed between the auxiliary roller and the terrain.

1 .- 24 . (canceled) 
     
     
         25 . A crawler traction device for a crawler vehicle, in particular a tractor, the crawler traction device comprising
 a frame;   a carriage having a longitudinal axis;   a rear drive sprocket fitted to the frame to rotate about a first axis crosswise to the longitudinal axis;   a front idler fitted to the carriage to rotate about a second axis parallel to the first axis; a track looped about the drive sprocket and the front idler and meshing with the drive sprocket along a meshing arc;   a damping device for reducing vibration caused in use by the moving vehicle; and   the idler defining a front portion of the damping device, and comprising a pair of identical front rollers fitted to a fork to rotate about the second axis; the fork being connected to the carriage by a tensioning device to allow the front rollers to slide in a direction parallel to the longitudinal axis.   
     
     
         26 . A crawler traction device as claimed in  claim 25 , further comprising a front idler wheel fitted to the carriage to rotate about a second axis parallel to the first axis, said pair of front rollers, are located on opposite sides of the idler wheel to rotate about respective axes of rotation parallel to each other and to the further second axis, are eccentric with respect to the idler wheel, have respective diameters smaller than that of the idler wheel, and only cooperate with the track along an initial portion of the winding arc of the track about the idler wheel. 
     
     
         27 . A crawler traction device as claimed in  claim 26 , wherein said axes of rotation are located above and to the front of the further second axis. 
     
     
         28 . A crawler traction device as claimed in  claim 26 , wherein the front rollers have different diameters, and rotate about respective parallel axes of rotation. 
     
     
         29 . A crawler traction device as claimed in  claim 26 , wherein the track comprises a chain of links, each of which comprises a respective shoe bound internally by a flat surface; and wherein each front roller has a respective peripheral surface coaxial with the relative axis of rotation and in constant contact with said flat surface at said initial portion. 
     
     
         30 . A crawler traction as claimed in  claim 29 , wherein the peripheral surface of each front roller is made of an elastic material. 
     
     
         31 . A crawler traction as claimed in any one of  claim 26 , wherein an idler wheel is fitted to the fork connected to the carriage by the tensioning device to allow the idler wheel to slide in a direction parallel to the longitudinal axis; and the front rollers are fitted in rotary manner to the fork. 
     
     
         32 . A crawler traction as claimed in  claim 31 , wherein the damping device further comprises, an adjusting device for each front roller for adjusting the longitudinal position of the front roller with respect to the fork. 
     
     
         33 . A crawler traction as claimed in  claim 31 , wherein the damping device comprises an adjusting device for each front roller for adjusting the height of the front roller with respect to the fork. 
     
     
         34 . A crawler traction as claimed in any one of  claim 31 , wherein each front roller is fitted to the fork by a bracket lockable in a longitudinally adjustable position with respect to the fork. 
     
     
         35 . A crawler traction as claimed in  claim 32  wherein the adjusting device for adjusting the longitudinal position comprises a pair of longitudinal slots formed in the bracket; and
 screws engaging the slots, and which lock the bracket with respect to the fork during normal operation, and are movable along the slots, during adjustment, to permit longitudinal movement of the bracket with respect to the fork. 
 
     
     
         36 . A device as claimed in  claim 35 , wherein the adjusting device for adjusting the longitudinal position comprises stop and adjusting device interposed between the bracket and the fork to adjust the longitudinal position of the bracket with respect to the fork. 
     
     
         37 . A device as claimed in  claim 32 , wherein the bracket comprises a first portion connected to the fork; and a second portion that rotatably supports the relative front roller, and is adjustably connected to the first portion; and wherein said adjusting device for adjusting the height comprises a number of slots formed in the first portion and extending substantially crosswise to the longitudinal axis; and
 screws engaging the slots, and that lock the second portion with respect to the first portion during normal operation, and are movable along the slots, during adjustment, to permit vertical movement of the second portion, together with the relative front roller with respect to the first portion.   
     
     
         38 . A device as claimed in  claim 36 , wherein the adjusting device for adjusting the height comprises stop and adjusting device interposed between the first and second portion to adjust the height of the second portion with respect to the first portion. 
     
     
         39 . A device as claimed in  claim 25 , wherein the track comprises a chain of links, each of which comprises a respective shoe bounded internally by a flat surface; and wherein the peripheral surface of each front roller is in constant contact with said flat surface along the whole winding arc of the track about the front rollers. 
     
     
         40 . A device as claimed in  claim 39 , wherein, on the side facing the other front roller, each front roller has a respective conical annular surface that cooperates with a relative tapered lateral surface of the links to align and guide the track along the whole winding arc.