Bando Chemical Industries, Inc.

Shigeki Okuno

Eijiro Nakashima

Hiroyuki Tachibana

Shogo Kobayashi

Katsuyoshi Fujiwara

Keizo Nonaka

Kimichika Ohno

Taiki Tsuchiya

Hisayuki Nakashima

Teppei Nakayama

Tomoyuki Fujikawa

Disclosed is a power transmission belt having a belt body made of rubber, and a cord embedded in the belt body so as to form a helical pattern having a pitch in a belt width direction. The cord is coated with an adhesion layer formed by an adhesion treatment and containing a rubber component, and the adhesion layer is in contact with a rubber composition containing cellulose-based fine fibers.

Transmission belt

A friction drive belt (B) includes short fibers () and carbon black () both scattered so as to be exposed at a surface of at least a contact part () of a rubber belt body () with a pulley. The short fibers () include short, high modulus fibers made of polymers having a main chain which does not contain an aromatic compound and having an initial tensile resistance, measured according to JIS L 1013, of equal to or greater than 100 cN/dtex, and the carbon black () contain large-particle-diameter carbon black having an iodine absorption, measured according to JIS K 6217-1, of equal to or less than 40 g/Kg, and/or a specific surface area, measured by nitrogen adsorption according to JIS K 6217-2, of equal to or less than 40 m/g.

Friction drive belt and automotive accessory drive belt transmission system using the same

The invention provides a transmission belt that can suppress lowering in transmission efficiency and has improved durability. A rubber layer adhered to core wires is formed to have a durometer hardness (shore A) of not less than 72 and not more than 85, or have a tensile stress of not less than 0.5 MPa and not more than 1.7 MPa when stretched 10% in the belt longitudinal direction at 25&#xb0; C., and the rubber layer is formed to have a weight increase of 90% or less after immersed in light oil for 48 hours at 25&#xb0; C. or have a weight increase of 80% or less after immersed in toluene for 48 hours at 25&#xb0; C. Alternatively, the rubber layer adhered to the core wires is formed to have a storage modulus of not less than 10 MPa and not more than 50 MPa and a tan &#x3b4; of not more than 0.15 as measured by dynamic viscoelasticity measurement under conditions at a static load of 3 kgf/cm, a dynamic strain of 0.4%, a frequency of 10 Hz and a temperature of 25&#xb0; C. in a tensile mode in a belt longitudinal direction.

A power transmission belt () includes: a belt body () including a part () which is in contact with a flat pulley and which is made of a rubber composition containing an ethylene-&#x3b1;-olefin elastomer with an ethylene content of less than or equal to 60% by mass as raw rubber. The rubber composition forming the contact part () with the flat pulley has a storage modulus of 20-60 MPa at 25&#xb0; C. and a storage modulus of 12 MPa or more at 100&#xb0; C., short fibers are not blended into the rubber composition, and the grain direction of the rubber composition corresponds to a belt lengthwise direction.

Power transmission belt

A friction drive belt includes: an adhesion rubber layer having a core wire embedded therein so as to form a helical pattern having a pitch in a lateral direction of the belt; a compression rubber layer provided on a surface of the adhesion rubber layer located on an inner side of the belt, and serving as a portion that is to contact pulleys, and a backing rubber layer provided on a surface of the adhesion rubber layer located on an outer side of the belt, and serving as a back portion of the belt. A ratio of tensile stress at 10% elongation of a rubber composition forming the adhesion rubber layer to that of a rubber composition forming the backing rubber layer is 1.77 or more, as measured in a longitudinal direction of the belt at an ambient temperature of 25&#xb0; C. according to JIS K 6251.

Friction drive belt

This invention has an object of enhancing the cold resistance of a heavy duty power transmission V-belt without impairing its durability at high temperatures, ensuring its sufficient power transmission capability and concurrently enhancing its permanent set resistance. To attain the object, the invention employs, for a rubber element of the belt, a rubber composition in which 20 to 40 parts by weight of a metal salt monomer of an organic acid and 5 to 35 parts by weight of short fibers are mixed into 100 parts by weight of a rubber component composed of EPDM and HNBR in their ratio of 55/45 to 75/25, the rubber hardness measured with a durometer Type D is 40 to 60, the value of tgiven by a Gehman torsion test is &#x2212;50&#xb0; C. to &#x2212;35&#xb0; C., and the amount of acetone extract from the rubber component is 9% or less.

Rubber composition for high-load transmission belt and high-load transmission belt from the rubber composition

A belt fabric which is provided at a part of a power transmission belt on which frictional forces act is formed by dipping into a rubber solution prepared by dissolving a non cross-linked hydrogenated nitrile rubber composition, mixed with a polyethylene powder having a molecular weight in excess of 1 million and an organic peroxide as a cross-linking agent, in a solvent.

Belt fabric, and power transmission belt and high load power transmission V-belt using such a belt fabric

The belt body of a power transmission belt is composed of a rubber composition comprising ethylene-&aacute;-olefin elastomer as the raw material rubber. The ethylene-&aacute;-olefin elastomer as the raw material rubber comprises 7 to 12 mass % of a high molecular weight component having a molecular weight of 10 or more and an ethylene content of 65 mass % or more, and 26 to 60 mass % of a low molecular weight component having a molecular weight of 10 or less and an ethylene content of 60 mass % or less, and the ethylene-&eacute;-olefin elastomer has a Mooney viscosity of 50 ML or less (100 C.).

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Kobe, Japan

Shigeki Okuno