Abstract: A toothed power transmission belt with a smooth back side surface has a back jacket on the back side surface; wherein the back jacket comprises a closed-mesh, knit fabric tube. The fabric tube may be knitted on a circular weft knitting machine and may be heat set after knitting. The fabric tube may be treated with an epoxy, RFL or other treatment to provide for oil resistance, adhesion, frictional properties, etc.

Abstract: belts and methods of manufacturing the same are described herein. The belt generally includes a base layer having a plurality of surface features (e.g., ribs or teeth) formed on a front surface of the base layer, and a stretched surface layer disposed on and conforming to the surface features. The stretched surface layer may comprise a knit fabric material that is from about 3 to about 10 wt. % elastomeric fiber or yarn and from about 90 to about 97 wt. % non-elastomeric yarn or fiber. The stretched surface layer is stretched over the front surface of the base layer such that the surface density of the stretched surface layer on the front surface is from about 100 to about 150 g/m2. Manufacturing methods for producing the belt with stretched surface layer generally includes disposing the surface layer on a planar front surface of the base layer and pressing a mold into the front surface of the base layer to thereby form a plurality of surface features in the front surface of the base layer.

Abstract: A synchronous belt drive system having: a synchronous belt with a tensile cord of high-modulus fiber such as glass, carbon, PBO, or aramid; a driver sprocket and at least one driven sprocket, at least one of which is an obround sprocket; and a tensioner having: a base having a cylindrical portion extending axially with a radially outer surface and a receiving portion, an eccentric arm pivotally engaged with the radially outer surface, a torsion spring disposed within the receiving portion, the torsion spring applying a biasing force to the eccentric arm, and a pulley journalled to the eccentric arm. Preferably, no one of the eccentric arm, pulley, or torsion spring is axially displaced along an axis A-A from the others. The obround sprocket has a toothed surface and at least one linear portion disposed between two arcuate portions having a constant radius, the linear portion having a predetermined length.

Abstract: A fabric for reinforcing a power transmission belt including fibers of polyarylene sulfide and a belt utilizing the fabric. The fabric may have textured or elastic core wrapped stretch yarns in the longitudinal direction. Longitudinal yarns may include PPS and textured transverse yarns include nylon. Yarns may include blends of high performance fibers and nylon or other fibers.

Abstract: A toothed power transmission belt with a smooth back side surface has a back jacket on the back side surface; wherein the back jacket comprises a closed-mesh, knit fabric tube. The fabric tube may be knitted on a circular weft knitting machine and may be heat set after knitting. The fabric tube may be treated with an epoxy, RFL or other treatment to provide for oil resistance, adhesion, frictional properties, etc.

Abstract: A fabric for reinforcing a power transmission belt including fibers of polyarylene sulfide and a belt utilizing the fabric. The fabric may have textured or elastic core wrapped stretch yarns in the longitudinal direction. Longitudinal yarns may include PPS and textured transverse yarns include nylon. Yarns may include blends of high performance fibers and nylon or other fibers.

Abstract: A cover fabric for a power transmission belt, the fabric woven from warp yarns and weft yarns; the warp yarns and weft yarns each plied from a first filament yarn and a second filament yarn; the first filament yarn comprising higher tensile strength fibers than the second filament yarn; and the fabric woven in a modified twill pattern. A toothed belt with the cover fabric on the teeth, oriented on a bias, with the fabric having a bias angle less than 90°.

Abstract: A synchronous belt drive system having: a synchronous belt with a tensile cord of high-modulus fiber such as glass, carbon, PBO, or aramid; a driver sprocket and at least one driven sprocket, at least one of which is an obround sprocket; and a tensioner having: a base having a cylindrical portion extending axially with a radially outer surface and a receiving portion, an eccentric arm pivotally engaged with the radially outer surface, a torsion spring disposed within the receiving portion, the torsion spring applying a biasing force to the eccentric arm, and a pulley journalled to the eccentric arm. Preferably, no one of the eccentric arm, pulley, or torsion spring is axially displaced along an axis A-A from the others. The obround sprocket has a toothed surface and at least one linear portion disposed between two arcuate portions having a constant radius, the linear portion having a predetermined length.

Abstract: A fabric for reinforcing a power transmission belt including fibers of polyarylene sulfide and a belt utilizing the fabric. The fabric may have textured or elastic core wrapped stretch yarns in the longitudinal direction. Longitudinal yarns may include PPS and textured transverse yarns include nylon. Yarns may include blends of high performance fibers and nylon or other fibers.

Abstract: A cover fabric for a power transmission belt, the fabric woven from warp yarns and weft yarns; the warp yarns and weft yarns each plied from a first filament yarn and a second filament yarn; the first filament yarn comprising higher tensile strength fibers than the second filament yarn; and the fabric woven in a modified twill pattern. A toothed belt with the cover fabric on the teeth, oriented on a bias, with the fabric having a bias angle less than 90°.

Abstract: A toothed power transmission belt with a smooth back side surface has a back jacket on the back side surface; wherein the back jacket comprises a closed-mesh, knit fabric tube. The fabric tube may be knitted on a circular weft knitting machine and may be heat set after knitting. The fabric tube may be treated with an epoxy, RFL or other treatment to provide for oil resistance, adhesion, frictional properties, etc.

Abstract: Compositions useful for power transmission belts or hose which utilize environmentally friendly cellulosic reinforcing fibers. The elastomeric or rubber compositions include a base elastomer, polyvinylpyrrolidone, a cellulosic fiber, and a curative. The base elastomer may be one or more selected from ethylene elastomers, nitrile elastomers, and polychloroprene elastomers. The elastomer may be an ethylene-alpha-olefin elastomer. The polyvinylpyrrolidone may be present in an amount of 5 to 50 parts weight per hundred parts of the elastomer. The cellulosic fiber may be one or more selected from kenaf, jute, hemp, flax, ramie, sisal, wood, rayon, acetate, triacetate, and cotton. The cellulosic fiber may be a bast fiber. The cellulosic fiber is present in an amount of 1 to 50 parts weight per hundred parts of the elastomer.

Abstract: A fabric for reinforcing a power transmission belt including fibers of polyarylene sulfide and a belt utilizing the fabric. The fabric may have textured or elastic core wrapped stretch yarns in the longitudinal direction. Longitudinal yarns may include PPS and textured transverse yarns include nylon. Yarns may include blends of high performance fibers and nylon or other fibers.

Abstract: A belt having an elastomeric body, a tensile cord embedded therein, and a tooth fabric having an increased value of Fabric Tensile Toughness as defined herein. The Fabric Tensile Toughness may be derived from properties of the yarns making up the fabric, such as yarn linear density, yarn ultimate elongation, yarn tensile strength, yarn packing density and weave ratio. The Fabric Tensile Toughness may be greater than 60 mJ/mm2. The belt may be a toothed belt of cast polyurethane with carbon fiber tensile cord. Also disclosed is a method of improving a known tooth cover fabric for a toothed power transmission belt involving selecting a different fabric having a higher Fabric Tensile Toughness than the known fabric and orienting the different fabric so the direction of highest Fabric Tensile Toughness is oriented in the longitudinal direction of the belt.

Abstract: A belt having an elastomeric body, a tensile cord embedded therein, and a tooth fabric having an increased value of Fabric Tensile Toughness as defined herein. The Fabric Tensile Toughness may be derived from properties of the yarns making up the fabric, such as yarn linear density, yarn ultimate elongation, yarn tensile strength, yarn packing density and weave ratio. The Fabric Tensile Toughness may be greater than 60 mJ/mm2. The belt may be a toothed belt of cast polyurethane with carbon fiber tensile cord. Also disclosed is a method of improving a known tooth cover fabric for a toothed power transmission belt involving selecting a different fabric having a higher Fabric Tensile Toughness than the known fabric and orienting the different fabric so the direction of highest Fabric Tensile Toughness is oriented in the longitudinal direction of the belt.

Abstract: A V-ribbed belt that includes a ribbed surface covered with fabric is provided. The fabric is stretchable in two predetermined directions. A method for manufacturing the V-ribbed belt is also provided. The method includes placing a belt matrix about a mandrel, placing a fabric about the external circumference of the belt matrix which wraps around the mandrel, placing the mandrel inside a shell having a plurality of grooves on the internal circumference, expanding the belt matrix and the fabric toward the internal circumference of the shell and thus pressing the fabric onto the internal circumference having the multi-ribbed structure, and curing the belt matrix with the fabric. The fabric is stretchable to accommodate itself to the multi-ribbed structure.

Abstract: A belt having a tensile cord embedded in the belt, extending in a longitudinal direction and made up of two components: a tensile component and a sacrificed component. The sacrificed component may be broken into a plurality of discontinuous segments. The tensile component provides most of the reinforcement of the belt. The sacrificial component of the precursor cord protects the tensile component from excessive stretching during cord treating and winding, but breaks, melts, or yields during mandrel expansion during the belt molding process, thus preserving the stretchability of the tensile component.

Abstract: A V-ribbed belt that includes a ribbed surface covered with fabric is provided. The fabric is stretchable in two predetermined directions. A method for manufacturing the V-ribbed belt is also provided. The method includes placing a belt matrix about a mandrel, placing a fabric about the external circumference of the belt matrix which wraps around the mandrel, placing the mandrel inside a shell having a plurality of grooves on the internal circumference, expanding the belt matrix and the fabric toward the internal circumference of the shell and thus pressing the fabric onto the internal circumference having the multi-ribbed structure, and curing the belt matrix with the fabric. The fabric is stretchable to accommodate itself to the multi-ribbed structure.

Abstract: Compositions useful for power transmission belts or hose which utilize environmentally friendly cellulosic reinforcing fibers. The elastomeric or rubber compositions include a base elastomer, polyvinylpyrrolidone, a cellulosic fiber, and a curative. The base elastomer may be one or more selected from ethylene elastomers, nitrile elastomers, and polychloroprene elastomers. The elastomer may be an ethylene-alpha-olefin elastomer. The polyvinylpyrrolidone may be present in an amount of 5 to 50 parts weight per hundred parts of the elastomer. The cellulosic fiber may be one or more selected from kenaf, jute, hemp, flax, ramie, sisal, wood, rayon, acetate, triacetate, and cotton. The cellulosic fiber may be a bast fiber. The cellulosic fiber is present in an amount of 1 to 50 parts weight per hundred parts of the elastomer.

Abstract: A belt having a tensile cord embedded in the belt, extending in a longitudinal direction and made up of two components: a tensile component and a sacrificed component. The sacrificed component may be broken into a plurality of discontinuous segments. The tensile component provides most of the reinforcement of the belt. The sacrificial component of the precursor cord protects the tensile component from excessive stretching during cord treating and winding, but breaks, melts, or yields during mandrel expansion during the belt molding process, thus preserving the stretchability of the tensile component.