Wear resistant belts, and a process for their manufacture

Abstract

Endless power transmission belts and processes for their manufacture, having power transmitting surfaces comprising a wear resistant composite, which belts exhibit improved abrasion- or wear resistance, reduced noise, reduced frictional heat generation, and improved dimensional stability compared to known belt constructions, as well as processes for manufacturing same. More particularly, an endless toothed belt having an abrasion- and noise resistant cover element, which comprises at least one friction-modifying constituent and at least one binder constituent.

1 - 16 . (canceled)  
   
   
       17 . A method for the manufacture of a power transmission belt ( 10 ) having a fabric cover ( 22 ) element positioned intimately along at least a portion of the outer surface of an elastomeric belt body, said fabric cover element ( 22 ) having a generally alternating arrangement of yarns and voids, the method characterized in that: 
 a) said fabric cover element ( 22 ) is treated with a fabric treatment material comprising at least one cross-linkable constituent, such that at least a portion of said voids remain at least partially free of said fabric treatment material;    b) a wear-resistant composite ( 20 ) comprising at least one binder constituent and at least one friction-modifying constituent is applied to a first surface only of said fabric cover element forming a power transmitting surface of the belt ( 10 );    c) at least a portion of said wear-resistant composite ( 20 ) is caused to penetrate into at least a portion of the total thickness of said fabric cover element but does not penetrate through the entire thickness thereof, such that at least a portion of said friction-modifying constituent resides within one or more said voids in said fabric cover element ( 22 ); and    d) at least a portion of said wear-resistant composite ( 20 ) is polymerized.    
   
   
       18 . The method of  claim 17  further characterized in that said fabric cover element ( 22 ) is applied to said surface of said elastomeric belt body after application of said wear-resistant composite ( 20 ) to said fabric cover element.  
   
   
       19 . The method of  claim 17  further characterized in that at least a portion of said friction-modifying constituent is separated from at least a portion of said binder constituent by a boundary.  
   
   
       20 . The method of  claim 17  further characterized in that said fabric treatment material is applied such that a pick-up rate of from about 1% to less than about 50% by weight of the dry fabric is achieved.  
   
   
       21 . The method of  claim 17  further characterized in that said fabric treatment material is applied such that a pick-up rate of from about 1% to about 30% by weight of the dry fabric is achieved.  
   
   
       22 . The method of  claim 17  further characterized in that a second treatment material comprising at least one cross-linkable constituent is applied to a second surface of said fabric cover element ( 22 ) after application of said wear-resistant composite ( 20 ), said second surface being opposite that surface on which said wear-resistant composite is applied.  
   
   
       23 . The method of  claim 22  wherein the pick-up rate of said second treatment material within said fabric cover element is from about 2.5% to about 55% based on the dry fabric weight.  
   
   
       24 . The method of  claim 17  further characterized in that at least one rubber bonding adhesive composition is applied to a second surface of said fabric cover element ( 22 ), said second surface being opposite to the surface on which said wear-resistant composite ( 20 ) is applied, and each said rubber bonding adhesive composition is applied at a pick-up rate in said fabric cover element ( 22 ) of up to about 70% based on the dry fabric weight.  
   
   
       25 . The method of  claim 22  further characterized in that, following application of said second treatment material, at least one rubber bonding adhesive composition is applied to at least said second surface of said fabric cover element ( 22 ), and each said rubber bonding adhesive composition is applied at a pick-up rate in said fabric cover element of up to about 70% based on the dry fabric weight.  
   
   
       26 . The method of  claim 17  further characterized in that it comprises applying said fabric cover element ( 22 ) to said portion of the outer surface of the elastomeric belt body, followed by vulcanizing the elastomeric belt body.  
   
   
       27 . A method according to  claim 17  for the manufacture of a toothed power transmission belt wherein the elastomeric body portion of said belt is tensile-loaded, and a plurality of spaced teeth ( 16 ) are bonded with and disposed along at least the inner periphery of the body portion, wherein: 
 a) said fabric cover element ( 22 ) is immersed said fabric treatment material to effect a pick-up rate of from about 1% to less than about 50%, based on the dry fabric weight;    b) the wear-resistant composite is applied to the first surface of said fabric cover element forming the power transmitting surface of said belt;    c) the fabric cover element is applied to the outer surface of said belt body; and    d) the belt body is vulcanized.    
   
   
       28 . The method of  claim 27  further characterized in that a second treatment material comprising at least one cross-linkable constituent is applied to a second surface of said fabric cover element prior to said application of said fabric cover element ( 22 ) to said belt body surface, said second surface being opposite that surface on which said wear resistant composite is applied.  
   
   
       29 . The method of  claim 28  further comprising the step of applying at least one additional rubber bonding adhesive composition to said second surface prior to said vulcanization  
   
   
       30 . A method for the manufacture of a power transmission belt ( 10 ) having a fabric cover ( 22 ) element positioned intimately along at least a portion of the outer surface of an elastomeric belt body, said fabric cover element ( 22 ) having a generally alternating arrangement of yarns and voids, the method characterized in that: 
 a) said fabric cover element ( 22 ) is treated with a fabric treatment material comprising at least one cross-linkable constituent, such that at least a portion of said voids remain at least partially free of said fabric treatment material, said fabric treatment material being applied such that a pick-up rate of from about 1% to about 50% by weight of the dry fabric is achieved;    b) a wear-resistant composite ( 20 ) comprising at least one binder constituent and at least one friction-modifying constituent is applied to at least a first surface of said fabric cover element forming a power transmitting surface of the belt ( 10 );    c) at least a portion of said wear-resistant composite ( 20 ) is caused to penetrate into at least a portion of the total thickness of said fabric cover element but does not penetrate through the entire thickness thereof, such that at least a portion of said friction-modifying constituent resides within one or more said voids in said fabric cover element ( 22 ); and    d) at least a portion of said wear-resistant composite ( 20 ) is polymerized.    
   
   
       31 . The method of  claim 30  further characterized in that a second treatment material comprising at least one cross-linkable constituent is applied to a second surface of said fabric cover element ( 22 ) after application of said wear-resistant composite ( 20 ), said second surface being opposite that surface on which said wear-resistant composite is applied.  
   
   
       32 . The method of  claim 30  wherein the pick-up rate of said second treatment material within said fabric cover element is from about 2.5% to about 55% based on the dry fabric weight.  
   
   
       33 . The method of  claim 30  further characterized in that at least one rubber bonding adhesive composition is applied to a second surface of said fabric cover element ( 22 ), said second surface being opposite to the surface on which said wear-resistant composite ( 20 ) is applied, and each said rubber bonding adhesive composition is applied at a pick-up rate in said fabric cover element ( 22 ) of up to about 70% based on the dry fabric weight.  
   
   
       34 . The method of  claim 31  further characterized in that, following application of said second treatment material, at least one rubber bonding adhesive composition is applied to at least said second surface of said fabric cover element ( 22 ), and each said rubber bonding adhesive composition is applied at a pick-up rate in said fabric cover element of up to about 70% based on the dry fabric weight.  
   
   
       35 . A method according to  claim 30  for the manufacture of a toothed power transmission belt wherein the elastomeric body portion of said belt is tensile-loaded, and a plurality of spaced teeth ( 16 ) are bonded with and disposed along at least the inner periphery of the body portion, wherein: 
 a) said fabric cover element ( 22 ) is immersed said fabric treatment material to effect a pick-up rate of from about 1% to less than about 30%, based on the dry fabric weight;    b) the wear-resistant composite is applied to the first surface of said fabric cover element forming the power transmitting surface of said belt;    c) the fabric cover element is applied to the outer surface of said belt body; and    d) the belt body is vulcanized.    
   
   
       36 . The method of  claim 35  further characterized in that a second treatment material comprising at least one cross-linkable constituent is applied to a second surface of said fabric cover element prior to said application of said fabric cover element ( 22 ) to said belt body surface, said second surface being opposite that surface on which said wear resistant composite is applied.  
   
   
       37 . The method of  claim 36  further comprising the step of applying at least one additional rubber bonding adhesive composition to said second surface prior to said vulcanization.  
   
   
       38 . A power transmission belt ( 10 ) comprising a fabric cover element ( 22 ) positioned intimately along at least a portion of the outer surface of an elastomeric belt body, said fabric cover element ( 22 ) having a generally alternating arrangement of yarns and voids; a wear-resistant composite ( 20 ) comprising at least one binder constituent and at least one friction-modifying constituent bonded to a first surface only of said fabric cover element ( 22 ) forming a power transmitting surface of the belt; and characterized in that: at least a portion of said wear-resistant composite penetrates into at least a portion of the total thickness of said fabric cover element but does not penetrate through the entire thickness thereof, such that at least a portion of said friction-modifying constituent resides within one or more said voids in said fabric cover element, and is separated from at least a portion of said binder constituent by a boundary; and at least a portion of said wear-resistant composite is polymerized, and at least a portion of said wear-resistant composite is separated from said belt body portion by a barrier.  
   
   
       39 . A power transmission belt ( 10 ) according to  claim 38 , which is obtainable by the method of  claim 17 .  
   
   
       40 . The power transmission belt ( 10 ) of  claim 38  wherein said barrier comprises at least one of said fabric treatment material and a second treatment material containing at least one cross-linkable constituent.  
   
   
       41 . The power transmission belt ( 10 ) of  claim 38  wherein said barrier comprises said fabric cover element, said fabric cover element possessing a weave, a warp and weft yarn type and a warp and weft yarn quantity, which together with said voids define a porosity, said porosity being characterized in that said wear-resistant composite penetrates less than the entire thickness of said fabric cover element.