Mitsuboshi Belting Ltd.

The present invention relates to a raw edge cogged V-belt, including: a cog at least on an inner circumferential surface side; and a compression rubber layer disposed on the inner circumferential surface side, in which the compression rubber layer includes a compression rubber layer main body and an inner surface layer covering an inner circumferential surface of the compression rubber layer main body, and a friction coefficient of a surface of the inner surface layer is higher than a friction coefficient of a surface of the compression rubber layer main body that is not covered with the inner surface layer.

A rubber composition for a power-transmission belt includes: a polymer component including an ethylene-α-olefin elastomer; carbon black; and clay, in which the ethylene-α-olefin elastomer has a Mooney viscosity at 125° C. of 25 ML (1+4) 125° C. or less, the clay has a pH of 5.5 or higher, a total amount of the carbon black and the clay is 80 parts by mass to 180 parts by mass with respect to 100 parts by mass of the polymer component, and a mass ratio of the carbon black to the clay is clay/carbon black=0.2/1 to 1.2/1.

A joined V-belt includes: a plurality of wrapped V-belt portions; and a tie band, in which outer peripheral surfaces of the wrapped V-belt portions are connected by the tie band. Each of the wrapped V-belt portions includes a belt body and a cover fabric covering an outer surface of the belt body. The belt body includes a tension member layer including a tension member, a tension rubber layer laminated on a belt outer peripheral side of the tension member layer, and a compression rubber layer laminated on a belt inner peripheral side of the tension member layer. The tie band includes a short fiber-containing rubber layer in which a short fiber is oriented in a belt width direction, and the short fiber-containing rubber layer includes a plurality of rib portions extending in a belt longitudinal direction.

A frictional power transmission belt includes a compression rubber layer having a frictional power transmission surface that is covered with a fabric. The compression rubber layer includes an inner rubber layer in contact with the fabric and an outer rubber layer on an outer peripheral side of the inner rubber layer. The inner rubber layer is formed of a cured product of a rubber composition including a surfactant as a hydrophilic plasticizer, an unsaturated carboxylic acid metal salt, and polyolefin particles.

An auto-tensioner includes: a base having a cylindrical part; an arm; a pulley around which a belt is to be wound; a friction member sandwiched between an inner circumferential surface of a cylindrical part and the arm; and a coil spring pressing the friction member against the arm in the axial direction and rotationally biasing the arm in one direction with respect to the base, in which the friction member includes: an arcuate surface, a first locking part, locked to the arm, and inclined with respect to the radial direction so as to face the one direction side as the first locking part goes toward an outside in the radial direction, and a second locking part, and the friction member and the arm include a restricting unit which restricts the friction member from moving toward the one direction side with respect to the arm.

A toothed belt including a reinforcing layer with 0.05 mm to 0.2 mm thickness buried along a contour of tooth portions such that a maximum height from a bottom portion of the tooth portion to the reinforcing layer is in a range of 30% to 100% of a height from the bottom portion to a tooth tip, in which the reinforcing layer includes reinforcing fiber filaments arranged in a belt circumferential direction, in the reinforcing layer, a weight per unit area of fibers intersecting the belt circumferential direction is 30% or less of a weight per unit area of the reinforcing fiber filaments, the reinforcing layer has a structure where the reinforcing fiber filaments are arranged in the belt circumferential direction and bonded to form a sheet shape in an untwisted state, and a tensile modulus of the reinforcing fiber filament satisfies a specific condition.

The present invention relates to a toothed belt including: a back portion; a tension member embedded in the back portion in a belt longitudinal direction and including a twisted cord including a steel fiber; a plurality of belt teeth formed on an inner peripheral side of the back portion along the belt longitudinal direction; and a cover layer provided between the tension member and a belt tooth bottom formed between the belt teeth, in which the cover layer has a thickness in a range of 0.2 mm to 1.0 mm, and the back portion, the belt teeth, and the cover layer are integrally formed of a thermoplastic elastomer.

A frictional power-transmission belt having a frictional power-transmission surface covered with a composite fiber layer, in which the composite fiber layer includes a fiber member and an isocyanate compound, and the fiber member includes a cellulose-based fiber. In the frictional power-transmission belt, the isocyanate compound may have a proportion of 3 to 20 mass % in the composite fiber layer.

The present invention relates to a raw edge cogged V-belt, including: a cog at least on an inner circumferential surface side; and a compression rubber layer disposed on the inner circumferential surface side, in which the compression rubber layer includes a compression rubber layer main body and an inner surface layer covering an inner circumferential surface of the compression rubber layer main body, and a friction coefficient of a surface of the inner surface layer is higher than a friction coefficient of a surface of the compression rubber layer main body that is not covered with the inner surface layer.

The present invention relates to a toothed belt, including: a back portion including a tension member; a plurality of tooth portions; a back rubber layer; and a first rubber layer and a second rubber layer that are formed on a belt inner circumferential side with respect to the tension member, in which an elastic modulus of the first rubber layer is larger than that of the second rubber layer, the first rubber layer includes a first crosslinked rubber composition including a first rubber component and a first short fiber, a proportion of the first short fiber is 5 parts by mass to 60 parts by mass with respect to 100 parts by mass of the first rubber component, the first short fiber is oriented in a belt longitudinal direction along a contour of the tooth portion.