This helically toothed belt power transmitting device (1) has: a toothed belt (10) having a plurality of teeth (12) tilted relative to the width direction of the belt; a drive pulley; and a driven pulley. The width of the helically toothed belt (10) is 1 mm to 20 mm, inclusive. The core (13) of the toothed belt (10) is a twisted cord containing high-strength glass fibers or carbon fibers and has a diameter of 0.2 mm to 0.9 mm, inclusive. The compressibility of the teeth (12) of the toothed belt (10) compressed by the grooves of the drive pulley and the driven pulley is 0% to 5%, inclusive.

This helically toothed belt power transmitting device (1) has: a toothed belt (10) having a plurality of teeth (12) tilted relative to the width direction of the belt; a drive pulley; and a driven pulley. The width of the helically toothed belt (10) is 1 mm to 20 mm, inclusive. The core (13) of the toothed belt (10) is a twisted cord containing high-strength glass fibers or carbon fibers and has a diameter of 0.2 mm to 0.9 mm, inclusive. The compressibility of the teeth (12) of the toothed belt (10) compressed by the grooves of the drive pulley and the driven pulley is 0% to 5%, inclusive.

A structure for belt installation of an engine for a vehicle is provided. The structure includes a damper pulley that is mounted to a crankshaft of the engine and a stretch belt that has a first end mounted on the damper pulley and a second end connected to an upper portion of a pulley portion of an accessory. The accessory is mounted on the engine at a position spaced apart from the damper pulley. The pulley portion includes a guide member on a front center thereof which guides installation of the stretch belt to the pulley portion.

A structure for belt installation of an engine for a vehicle is provided. The structure includes a damper pulley that is mounted to a crankshaft of the engine and a stretch belt that has a first end mounted on the damper pulley and a second end connected to an upper portion of a pulley portion of an accessory. The accessory is mounted on the engine at a position spaced apart from the damper pulley. The pulley portion includes a guide member on a front center thereof which guides installation of the stretch belt to the pulley portion.

A fabric layer includes a fabric and a crosslinkable elastomer, where the fabric defines a first side and the crosslinkable elastomer defines an opposing side. The fabric is coated with a crosslinkable elastomer and the combination is molded into a multiple tooth shaped fabric layer. In some aspects, the first side is an inner surface void of the crosslinkable elastomer. In some cases, the crosslinkable elastomer is crosslinked while the fabric layer is molded, while in some other cases, the crosslinkable elastomer is surface cured while the fabric layer is molded. The crosslinkable elastomer may be an alloy of crosslinkable polyethylene and EPDM. The fabric layer may be used as an outer layer of a synchronous drive belt, a timing belt, a poly-v belt, or offset tooth belt.

A fabric layer includes a fabric and a crosslinkable elastomer, where the fabric defines a first side and the crosslinkable elastomer defines an opposing side. The fabric is coated with a crosslinkable elastomer and the combination is molded into a multiple tooth shaped fabric layer. In some aspects, the first side is an inner surface void of the crosslinkable elastomer. In some cases, the crosslinkable elastomer is crosslinked while the fabric layer is molded, while in some other cases, the crosslinkable elastomer is surface cured while the fabric layer is molded. The crosslinkable elastomer may be an alloy of crosslinkable polyethylene and EPDM. The fabric layer may be used as an outer layer of a synchronous drive belt, a timing belt, a poly-v belt, or offset tooth belt.

The present invention relates to a helical toothed belt including: a back portion in which a tension member is buried; and a plurality of tooth portions, in which: the plurality of tooth portions have a tooth pitch of 2 mm or more and less than 4 mm, in a case where the tooth pitch of the plurality of tooth portions is 2 mm or more and less than 3 mm, the back portion has a thickness of 0.4 mm or more and 1.2 mm or less, in a case where the tooth pitch of the plurality of tooth portions is 3 mm or more and less than 4 mm, the thickness of the back portion is 0.6 mm or more and 1.8 mm or less; and the tension member is a twisted cord including a high-strength glass fiber or a carbon fiber.

The present invention relates to a helical toothed belt including: a back portion in which a tension member is buried; and a plurality of tooth portions, in which: the plurality of tooth portions have a tooth pitch of 2 mm or more and less than 4 mm, in a case where the tooth pitch of the plurality of tooth portions is 2 mm or more and less than 3 mm, the back portion has a thickness of 0.4 mm or more and 1.2 mm or less, in a case where the tooth pitch of the plurality of tooth portions is 3 mm or more and less than 4 mm, the thickness of the back portion is 0.6 mm or more and 1.8 mm or less; and the tension member is a twisted cord including a high-strength glass fiber or a carbon fiber.

A synchronous belt drive system having: a synchronous belt with a tensile cord of high-modulus fiber such as glass, carbon, PBO, or aramid; a driver sprocket and at least one driven sprocket, at least one of which is an obround sprocket; and a tensioner having: a base having a cylindrical portion extending axially with a radially outer surface and a receiving portion, an eccentric arm pivotally engaged with the radially outer surface, a torsion spring disposed within the receiving portion, the torsion spring applying a biasing force to the eccentric arm, and a pulley journalled to the eccentric arm. Preferably, no one of the eccentric arm, pulley, or torsion spring is axially displaced along an axis A-A from the others. The obround sprocket has a toothed surface and at least one linear portion disposed between two arcuate portions having a constant radius, the linear portion having a predetermined length.

A synchronous belt drive system having: a synchronous belt with a tensile cord of high-modulus fiber such as glass, carbon, PBO, or aramid; a driver sprocket and at least one driven sprocket, at least one of which is an obround sprocket; and a tensioner having: a base having a cylindrical portion extending axially with a radially outer surface and a receiving portion, an eccentric arm pivotally engaged with the radially outer surface, a torsion spring disposed within the receiving portion, the torsion spring applying a biasing force to the eccentric arm, and a pulley journalled to the eccentric arm. Preferably, no one of the eccentric arm, pulley, or torsion spring is axially displaced along an axis A-A from the others. The obround sprocket has a toothed surface and at least one linear portion disposed between two arcuate portions having a constant radius, the linear portion having a predetermined length.