Provided is a rubber composition capable of suppressing deterioration of adhesiveness to a reinforcing member even in the case of having been subjected to repeated flex fatigue. The rubber composition is obtainable by compounding a rubber component containing a diene based rubber, a wet silica, a carbon black, and a calcium carbonate, wherein: a compounding amount of the wet silica is 3 parts by mass or more per 100 parts by mass of the diene based rubber; a nitrogen adsorption BET specific surface area of the carbon black is 8 m.sup.2/g or more and 100 m.sup.2/g or less; and the following formula 0.5X+28YX+88 is satisfied, where X represents the nitrogen adsorption BET specific surface area of the carbon black in terms of m.sup.2/g, and Y represents a compounding amount of the calcium carbonate in terms of parts by mass per 100 parts by mass of the diene based rubber.

A hybrid cable having a core and a wrap; the core made from a carbon fiber yarn or bundle of carbon fiber strands or yarns; and the wrap made of a plurality of metal wires helically wrapped around the core, the plurality of metal wires laid side by side without crossing each other. The fibers, yarns, or core may be treated with polymeric sizing, adhesive, or binder. The wire may be steel and may have a coating such as brass or zinc plating, or a polymeric coating or treatment. The hybrid cable is useful for reinforcing composite articles such as belts, track, or hose.

The present invention pertains to a frictional power transmission belt including a tension member extending in the longitudinal direction of the belt and an adhesion rubber layer in contact with at least a portion of the tension member, in which the adhesion rubber layer is formed of a vulcanized rubber composition containing a rubber component, short fibers having an average fiber diameter of 2 m or more, and a filler.

In a friction transmission belt including a rubber layer forming a pulley contact surface, the rubber layer includes a rubber composition containing hydrophilic inorganic filler and a sliding-resistant material. The sliding-resistant material protrudes from the pulley contact surface, and is at least one of hydrophobic resin particles and hydrophobic resin fibers having an official regain of 0.4% or below, and in the rubber composition, a content of the hydrophilic inorganic filler with respect to 100 parts by mass of the rubber component is 35 parts by mass or more.

In a friction transmission belt including a rubber layer forming a pulley contact surface, the rubber layer includes a rubber composition containing polyolefin particles and an inorganic filler. In the rubber composition, a total content of the polyolefin particles and the inorganic filler with respect to 100 parts by mass of a rubber component is 85 parts by mass or more.

A belt and sprocket system comprising a tensile cord disposed within a belt body, at least two teeth projecting from the belt body, the belt comprising a pitch length measured between the at least two teeth on the belt, one of the at least two teeth having a tooth tip and a profile comprising a first radius and a second radius and a third radius disposed between a first linear segment and a second linear segment, the sprocket having a groove for receiving one of the at least two teeth, the groove profile comprising a first radius and a second radius and the third radius and a fourth radius, each of which is connected in series to the others and each of which is unequal in length to the other radii, the tooth having a width that is approximately 35% of a pitch length at 90% of a tooth height so as to result in an interference fit between the one of at least two teeth and groove at 90% of the tooth height; and a volume between the tooth tip and the groove.

A belt and sprocket system comprising a tensile cord disposed within a belt body, at least two teeth projecting from the belt body, the belt comprising a pitch length measured between the at least two teeth on the belt, one of the at least two teeth having a tooth tip and a profile comprising a first radius and a second radius and a third radius disposed between a first linear segment and a second linear segment, the sprocket having a groove for receiving one of the at least two teeth, the groove profile comprising a first radius and a second radius and the third radius and a fourth radius, each of which is connected in series to the others and each of which is unequal in length to the other radii, the tooth having a width that is approximately 35% of a pitch length at 90% of a tooth height so as to result in an interference fit between the one of at least two teeth and groove at 90% of the tooth height; and a volume between the tooth tip and the groove.

A power transmission belt has a front rubber face and a back rubber surface. The back rubber surface has an uneven surface of rubber which, when the power transmission belt is wound around a flat pulley, comes in contact with the flat pulley. The uneven surface of rubber has a pattern created by a mold having an impression of a surface of a woven fabric or a knitted fabric. The impression has projected parts and recessed parts, and each of the projected parts has a flat top surface. The power transmission belt is wound around a number of pulleys in a belt transmission system in which the pulleys include a flat pulley with which the uneven surface of the power transmission belt comes in contact.

A power transmission belt has a front rubber face and a back rubber surface. The back rubber surface has an uneven surface of rubber which, when the power transmission belt is wound around a flat pulley, comes in contact with the flat pulley. The uneven surface of rubber has a pattern created by a mold having an impression of a surface of a woven fabric or a knitted fabric. The impression has projected parts and recessed parts, and each of the projected parts has a flat top surface. The power transmission belt is wound around a number of pulleys in a belt transmission system in which the pulleys include a flat pulley with which the uneven surface of the power transmission belt comes in contact.

The present invention relates to a flat belt (10) that is an open end belt to be fixed to a coupler (31, 41), in which the flat belt (10) contains, formed on both end portions (11, 12) of at least one surface of the flat belt (10), a plurality of projected portions (13) engageable with a plurality of recessed portions (33, 43) formed on the coupler (31, 41).