High volume conveyor transport for clean environments

Abstract

A segmented, belt-driven conveyor system for use in clean environments. High speed, high density, collision free throughput of work piece carriers is enabled through belt-driven conveyor segments each having co-rotating drive wheels. The drive wheels have a cylindrical profile. Predefined acceleration/deceleration profiles may be employed by a motor controller to affect optimal changes in work piece carrier speed across the respective drive segment. A peripheral groove is formed in idler wheels within a drive segment. A soft, pliant ring of material is disposed in the groove. The ring protrudes slightly beyond the crown of each wheel. The drive belt then remains in contact with the ring when unloaded and the wheel peripheral surface itself when loaded through compression of the pliant ring. By reducing intermittent contact between the belt and the wheels, particulation is reduced.

What is claimed is: 
     
         1 . A wheel for supporting a drive belt in a belted conveyor system, the wheel comprising:
 a substantially cylindrical wheel hub having a radially-extending outer periphery, the outer periphery having a front edge and a back edge;   a slot formed in the wheel hub outer periphery between the front edge and the back edge; and   a ring of pliant material disposed within the slot,   wherein the maximum thickness of the ring of pliant material, measured in the radial direction, is greater than the maximum depth of the slot, measured in the radial direction.   
     
     
         2 . The wheel of  1 , wherein the slot has a rectangular cross-section. 
     
     
         3 . The wheel of  1 , wherein the ring of pliant material has a rectangular cross-section. 
     
     
         4 . The wheel of  1 , wherein the wheel hub has a hardness greater than a hardness of the ring of pliant material. 
     
     
         5 . The wheel of  1 , where in the ring of pliant material is friction fit within the slot. 
     
     
         6 . The wheel of  1 , where the diameter of the outer periphery of the wheel hub increases from the front and back edges towards the center of the periphery. 
     
     
         7 . The wheel of  1 , further comprising a bearing assembly. 
     
     
         8 . A conveyor segment, comprising:
 a drive rail;   a plurality of idler wheels disposed in a linear array from the drive rail;   a drive wheel disposed from the drive rail; and   a continuous belt disposed above the plurality of idler wheels and about at least a portion of the drive wheel,   wherein each of the plurality of idler wheels comprises a peripherally formed slot and a ring of pliant material disposed within the slot and projecting therefrom, the ring of pliant material in contact with an underside of the belt, the wheels having a material hardness greater than that of the ring of pliant material.