Friction transmission belt and method for fabricating same, and belt transmission system
A friction transmission belt has a belt body made of a rubber composition and wrapped around pulleys to transmit power. The belt includes a thermoplastic resin film provided to coat a pulley contact surface of the belt body, and a powder layer comprised of reduced friction coefficient powder particles provided on a surface side of the thermoplastic resin film. The powder layer includes powder particles buried in the thermoplastic resin film, powder particles carried and exposed on the surface of the thermoplastic resin film, and powder particles agglomerated and adhering to the powder particles carried and exposed on the surface of the thermoplastic resin film.
1. A friction transmission belt comprising:
a belt body made of a rubber composition adapted to wrap around pulleys to transmit power
a thermoplastic resin film coated on a pulley contact surface of the belt body, said thermoplastic resin film comprising a first set of reduced friction coefficient powder particles buried therein; and
a powder layer comprising a second set and a third set of reduced friction coefficient powder particles,
wherein the second set of reduced friction coefficient powder particles are carried and exposed on the surface of the thermoplastic resin film, and
the third set of reduced friction coefficient powder particles are agglomerated and adhered to the second set of reduced friction coefficient powder particles carried and exposed on the surface of the thermoplastic resin film.
2. The friction transmission belt of claim 1 , wherein a cloth is buried in the thermoplastic resin film.
3. The friction transmission belt of claim 2 , wherein the cloth is a knitted fabric.
4. The friction transmission belt of claim 1 , wherein the thermoplastic resin film has a thickness of 0.1 to 200 μm.
5. The friction transmission belt of claim 1 , wherein a softening temperature or a melting point of a thermoplastic resin that forms the thermoplastic resin film is 100 to 170° C.
6. The friction transmission belt of claim 1 , wherein the thermoplastic resin film is made of polyethylene resin.
7. The friction transmission belt of claim 1 , wherein the reduced friction coefficient powder particles forming the powder layer have a particle size of 0.1 to 150 μm.
8. The friction transmission belt of claim 1 , wherein the reduced friction coefficient powder particles forming the powder layer are made of fluorocarbon resin.
9. The friction transmission belt of claim 1 , wherein the belt body is a V-ribbed belt body.
10. The friction transmission belt of claim 1 comprising:
the belt body made of a rubber composition adapted to wrap around pulleys to transmit power, wherein
the powder layer formed beforehand by spraying the reduced friction coefficient powder particles on a molding surface of a belt forming mold on which the pulley contact side of the friction transmission belt is formed,
a belt formation body comprised of an uncrosslinked rubber composition coated with a thermoplastic resin which is pressure welded to the powder layer, and
the uncrosslinked rubber composition which is cross-linked at a molding temperature at which the reduced friction coefficient powder particles do not melt and at which the thermoplastic resin becomes soft or melts.
11. A belt transmission system, comprising:
the friction transmission belt of claim 10 , and
a plurality of pulleys around which the belt body of the friction transmission belt is wrapped.
12. A belt transmission system, comprising:
the friction transmission belt of claim 1 , and
a plurality of pulleys around which the belt body of the friction transmission belt is wrapped.
13. The belt transmission system of claim 12 , wherein the plurality of pulleys include a pair of pulleys between which a belt span length of the friction transmission belt is 40 to 100 mm.
14. The belt transmission system of claim 13 , wherein misalignment between the pair of pulleys is 0.5 to 2.0°.
15. A method for fabricating the friction transmission belt of claim 1 comprising:
forming the powder layer beforehand by spraying the reduced friction coefficient powder particles on a molding surface of a belt forming mold on which the pulley contact side of the friction transmission belt is formed,
coating a belt formation body comprised of an uncrosslinked rubber composition with a thermoplastic resin which is pressure welded to the powder layer, and
cross-linking the uncrosslinked rubber composition at a molding temperature at which the reduced friction coefficient powder particles do not melt and at which the thermoplastic resin becomes soft or melts.
16. The method of claim 15 , further comprising intervening a cloth between the uncrosslinked rubber composition and the thermoplastic resin in the belt formation body.
17. The friction transmission belt of claim 1 , wherein the powder layer has irregularities on its surface.
18. The friction transmission belt of claim 1 , wherein a rubber component of the rubber composition that makes the pulley contact surface of the belt body is EPDM.