A high torque sprocket includes a body defining an outer periphery and a hub section defining an inner surface for engaging a bushing. A continuous toothed structure is disposed on the outer periphery of the body, and a textile reinforcement embedded in the body adjacent the inner surface of the hub section. The body is formed of a castable polymer material. In some cases, one or two optional flanges are disposed on side(s) of the body immediately adjacent the continuous toothed structure, in some aspects, a textile reinforcement may be embedded in a surface of the flange(s) immediately adjacent the continuous toothed structure. In some aspects, ultra-high molecular weight polyethylene (UHMWPE) is incorporated into the castable polymer material mixture in an amount suitable to provide increased durability to the sprocket.

A stepless transmission transmits a driving force by an endless transmission member (5) wound around a V-groove (6) of an input pulley (1). The input pulley (1) has moving parts (9) which are fastened by threaded engagement so as to be axially movable with respect to a transmission case (3) and have ring gears (10), to which rotation can be input from the outer periphery sides, and pulley half discs (13) which are relatively rotatable with respect to the moving parts (9), which axially move integrally with the moving parts (9) and which are contactable with an endless transmission member (5). The pulley half discs (13) and an input shaft 2, which is disposed at the center of the pulley half discs (13), rotate together as one piece. The ring gears (10) are each rotationally driven from a drive source of the same drive member.

A stepless transmission transmits a driving force by an endless transmission member (5) wound around a V-groove (6) of an input pulley (1). The input pulley (1) has moving parts (9) which are fastened by threaded engagement so as to be axially movable with respect to a transmission case (3) and have ring gears (10), to which rotation can be input from the outer periphery sides, and pulley half discs (13) which are relatively rotatable with respect to the moving parts (9), which axially move integrally with the moving parts (9) and which are contactable with an endless transmission member (5). The pulley half discs (13) and an input shaft 2, which is disposed at the center of the pulley half discs (13), rotate together as one piece. The ring gears (10) are each rotationally driven from a drive source of the same drive member.

A resin pulley includes a rolling bearing having an outer race. The outer race has, on the radially outer surface, two annular grooves, and an annular protrusion between the annular grooves. The annular protrusion has recesses and projections disposed circumferentially alternating with the recesses, the recesses and the projections being formed by straight knurling by rolling on the radially outer surface of the annular protrusion such that both ends thereof extend to the respective annular grooves. The diameter of the circle that contacts, from radially inwardly, bottoms of the recesses is larger than that of the circular bottom of each annular groove. The pulley body includes protrusions formed by filling a molten resin in the recesses and solidifying the molten resin, when forming the pulley body on the radially outer surface of the outer race by resin molding. This prevents creep of the outer race.

A resin pulley includes a rolling bearing having an outer race. The outer race has, on the radially outer surface, two annular grooves, and an annular protrusion between the annular grooves. The annular protrusion has recesses and projections disposed circumferentially alternating with the recesses, the recesses and the projections being formed by straight knurling by rolling on the radially outer surface of the annular protrusion such that both ends thereof extend to the respective annular grooves. The diameter of the circle that contacts, from radially inwardly, bottoms of the recesses is larger than that of the circular bottom of each annular groove. The pulley body includes protrusions formed by filling a molten resin in the recesses and solidifying the molten resin, when forming the pulley body on the radially outer surface of the outer race by resin molding. This prevents creep of the outer race.

A friction pulley includes a rotatable rotary wheel having a groove on an outer periphery thereof, and a rubber ring formed so as to be able to be accommodated in the groove. The groove has a pair of side surfaces. The rubber ring has a contact surface which is brought into pressure contact with a rotary member so as to transmit power on an outer periphery thereof, and friction surfaces which are a pair of surfaces corresponding to the groove. At least in a power transmission state where the contact portion is brought into pressure contact with the rotary member so as to transmit power, the friction surfaces of the rubber ring are pushed to the side surfaces of the groove. The friction pulley-includes separation preventing devices for preventing separation of the rubber ring from the groove in an outward direction.

A friction pulley includes a rotatable rotary wheel having a groove on an outer periphery thereof, and a rubber ring formed so as to be able to be accommodated in the groove. The groove has a pair of side surfaces. The rubber ring has a contact surface which is brought into pressure contact with a rotary member so as to transmit power on an outer periphery thereof, and friction surfaces which are a pair of surfaces corresponding to the groove. At least in a power transmission state where the contact portion is brought into pressure contact with the rotary member so as to transmit power, the friction surfaces of the rubber ring are pushed to the side surfaces of the groove. The friction pulley-includes separation preventing devices for preventing separation of the rubber ring from the groove in an outward direction.

A friction pulley includes a rotary wheel having a groove on an outer periphery of the rotary wheel rotatable about an axis, the groove being recessed toward an inner periphery side, and a rubber ring having an annular shape and can be accommodated in the groove. The groove has a pair of annular side surfaces facing each other in a direction of the axis and extending from an inner peripheral side toward an outer peripheral side. The rubber ring has a contact surface at an outer periphery of the rubber ring and friction surfaces that are a pair of surfaces corresponding to the pair of side surfaces of the groove. At least in a power transmission state where the contact surface is in pressure contact with the rotary member to transmit power, the friction surfaces of the rubber ring are pushed against the side surfaces of the groove.

A friction pulley includes a rotary wheel having a groove on an outer periphery of the rotary wheel rotatable about an axis, the groove being recessed toward an inner periphery side, and a rubber ring having an annular shape and can be accommodated in the groove. The groove has a pair of annular side surfaces facing each other in a direction of the axis and extending from an inner peripheral side toward an outer peripheral side. The rubber ring has a contact surface at an outer periphery of the rubber ring and friction surfaces that are a pair of surfaces corresponding to the pair of side surfaces of the groove. At least in a power transmission state where the contact surface is in pressure contact with the rotary member to transmit power, the friction surfaces of the rubber ring are pushed against the side surfaces of the groove.

A belt pulley for a gear mechanism, in particular for a steering gear, having a cylindrical body having an outer surface on which a toothing made of a plastic material is provided, and a fastening flange which is provided with fastening openings, is characterized in that the toothing is configured integrally with the cylindrical body.