An uncrosslinked rubber shaped structure for belt production is placed in a belt mold with the uncrosslinked rubber shaped structure having a bent portion that is bent inward. A space inside the uncrosslinked rubber shaped structure is partitioned into a first space and a second space. The first space corresponds to a first shaped structure portion of the uncrosslinked rubber shaped structure, the first shaped structure portion including the bent portion. The second space corresponds to a second shaped structure portion of the uncrosslinked rubber shaped structure that is a portion of the uncrosslinked rubber shaped structure except the first shaped structure portion. An expansion member is expanded in the second space to press the second shaped structure portion toward the belt mold.

The present invention pertains to a friction transmission belt that includes a core cable. The core cable includes a cord comprising: a core yarn containing high elastic-modulus fibers; and a plurality of sheath yarns that are disposed around the core yarn and that contain low elastic-modulus fibers. The cord is twisted and the proportion of the average diameter of the sheath yarn to the average diameter of the core yarn is 0.2 to 0.4.

The present invention pertains to a friction transmission belt that includes a core cable. The core cable includes a cord comprising: a core yarn containing high elastic-modulus fibers; and a plurality of sheath yarns that are disposed around the core yarn and that contain low elastic-modulus fibers. The cord is twisted and the proportion of the average diameter of the sheath yarn to the average diameter of the core yarn is 0.2 to 0.4.

A cord of a toothed belt is made of a twisted yarn including a band-like material. The band-like material includes a filament bundle of high-strength glass fibers integrated together through a binder. The binder contains a rubber component, at least either a maleimide-based compound or a polyisocyanate compound, and a powdery inorganic filler. A surface of a reinforcing fabric facing opposite to the toothed belt body is coated with a surface-coating rubber layer made of a rubber composition containing a rubber component including hydrogenated nitrile-butadiene rubber as a main part.

A power transmission belt is at least partially formed of a rubber composition. The rubber composition contains a rubber component, cellulose nanofibers, and carbon black. The amount of the cellulose nanofibers to be added is from 0.1 parts by mass to 20 parts by mass, relative to 100 parts by mass of the rubber component. The amount of the carbon black to be added is from 5 parts by mass to 80 parts by mass, relative to 100 parts by mass of the rubber component. The sum of the amount of the carbon black to be added and three times the amount of the cellulose nanofibers to be added is from 15 to 90.

A power transmission belt is at least partially formed of a rubber composition. The rubber composition contains a rubber component, cellulose nanofibers, and carbon black. The amount of the cellulose nanofibers to be added is from 0.1 parts by mass to 20 parts by mass, relative to 100 parts by mass of the rubber component. The amount of the carbon black to be added is from 5 parts by mass to 80 parts by mass, relative to 100 parts by mass of the rubber component. The sum of the amount of the carbon black to be added and three times the amount of the cellulose nanofibers to be added is from 15 to 90.

A power transmission belt at least includes a bottom rubber layer. A rubber composition for forming the bottom rubber layer contains a rubber component, cellulose fine fibers, and short fibers. The cellulose fine fibers have an average diameter from 1 nm to 200 nm, and the rubber composition contains 0.5 parts by mass or more of the cellulose fine fibers relative to 100 parts by mass of the rubber component. The short fibers have an average diameter from 5 m to 30 m, and the rubber composition contains 1 part by mass or more of the short fibers relative to 100 parts by mass the rubber component.

A power transmission belt at least includes a bottom rubber layer. A rubber composition for forming the bottom rubber layer contains a rubber component, cellulose fine fibers, and short fibers. The cellulose fine fibers have an average diameter from 1 nm to 200 nm, and the rubber composition contains 0.5 parts by mass or more of the cellulose fine fibers relative to 100 parts by mass of the rubber component. The short fibers have an average diameter from 5 m to 30 m, and the rubber composition contains 1 part by mass or more of the short fibers relative to 100 parts by mass the rubber component.

A belt-type traction apparatus includes a herringbone toothed belt, which includes two edge parts and a center part between the two edge parts in a transverse direction of the herringbone toothed belt and connecting the edge parts in the transverse direction. The two edge parts and the center part each extend in a longitudinal direction of the herringbone toothed belt. The center part is associated with a first spring constant, the two edge parts are each associated with a second spring constant, and the first spring constant smaller than the second spring constant. Each edge part includes a tooth part and a support structure supporting the tooth part. Each support structure includes a plurality of reinforcement members extending in the longitudinal direction of the toothed belt.

A belt-type traction apparatus includes a herringbone toothed belt, which includes two edge parts and a center part between the two edge parts in a transverse direction of the herringbone toothed belt and connecting the edge parts in the transverse direction. The two edge parts and the center part each extend in a longitudinal direction of the herringbone toothed belt. The center part is associated with a first spring constant, the two edge parts are each associated with a second spring constant, and the first spring constant smaller than the second spring constant. Each edge part includes a tooth part and a support structure supporting the tooth part. Each support structure includes a plurality of reinforcement members extending in the longitudinal direction of the toothed belt.