A pulley assembly having a body, a shaft mount and a plurality of bolts is disclosed. The body is aligned to the shaft mount by providing a tight tolerance between a shoulder portion of the bolt and a neck portion of a counter sunk hole formed in the body. Additionally, an outer surface of the body may have a pattern of friction lines or patches formed by fusing particulate matter to the outer surface with heat generated by a laser beam.

A pulley assembly having a body, a shaft mount and a plurality of bolts is disclosed. The body is aligned to the shaft mount by providing a tight tolerance between a shoulder portion of the bolt and a neck portion of a counter sunk hole formed in the body. Additionally, an outer surface of the body may have a pattern of friction lines or patches formed by fusing particulate matter to the outer surface with heat generated by a laser beam.

Construction is achieved by which it is possible definitely prevent the occurrence of creep between a pulley 2b and an outer ring 7f. Trapezoidal shaped concave sections are formed such that the angle of intersection θ between the inside surfaces 23 on both sides of each concave section 17a of knurling 19a of the outer ring 7f is within the range 45°≦θ≦120°. Moreover, the depth h in the radial direction of the concave sections 17a and the diameter D of the circumscribed circle of the tip end surfaces 22 of the convex sections 18a are regulated so as to satisfy the relationship 0.004D≦h≦0.015D, and the length L in the circumferential direction of the bottom surface 21 of the concave sections 17a is regulated within the range 0.01D≦L≦0.03D.

Construction is achieved by which it is possible definitely prevent the occurrence of creep between a pulley 2b and an outer ring 7f. Trapezoidal shaped concave sections are formed such that the angle of intersection θ between the inside surfaces 23 on both sides of each concave section 17a of knurling 19a of the outer ring 7f is within the range 45°≦θ≦120°. Moreover, the depth h in the radial direction of the concave sections 17a and the diameter D of the circumscribed circle of the tip end surfaces 22 of the convex sections 18a are regulated so as to satisfy the relationship 0.004D≦h≦0.015D, and the length L in the circumferential direction of the bottom surface 21 of the concave sections 17a is regulated within the range 0.01D≦L≦0.03D.

A backside idler pulley includes a first member forming a first side wall of a circumferential groove of the backside idler pulley and a second member, formed separately from the first member, and forming a second side wall, opposite the first side wall, of the circumferential groove of the backside idler pulley. The first member and the second member form first and second floor supports, respectively. The backside idler pulley further includes a continuous layer between the first side wall and the second side wall, the continuous layer being supported by the first and second floor supports while forming a floor of the groove.

A backside idler pulley includes a first member forming a first side wall of a circumferential groove of the backside idler pulley and a second member, formed separately from the first member, and forming a second side wall, opposite the first side wall, of the circumferential groove of the backside idler pulley. The first member and the second member form first and second floor supports, respectively. The backside idler pulley further includes a continuous layer between the first side wall and the second side wall, the continuous layer being supported by the first and second floor supports while forming a floor of the groove.

A damper and pulley assembly for an internal combustion engine is disclosed. The damper and pulley assembly, including a pulley closely fitted between two dampers, is configured to have increased air movement for heat dissipation while conforming to low spacing requirements of an engine compartment. The pulley can have multiple slots along its two side surfaces and openings located in the slots. The slots and openings of the pulley are aligned with openings of the two dampers, and facilitate air movement through the pulley and around the dampers.

A damper and pulley assembly for an internal combustion engine is disclosed. The damper and pulley assembly, including a pulley closely fitted between two dampers, is configured to have increased air movement for heat dissipation while conforming to low spacing requirements of an engine compartment. The pulley can have multiple slots along its two side surfaces and openings located in the slots. The slots and openings of the pulley are aligned with openings of the two dampers, and facilitate air movement through the pulley and around the dampers.

A filtering pulley has a hub configured to be fixed to a shaft for rotation thereabout, a crown mounted coaxial and rotationally free on the hub, and a plurality of elastic groups arranged circumferentially with respect to the hub and to the crown and interposed, each, between a pair of first elements integral with the hub and between a pair of second elements integral with the crown. The first elements have at least two spokes, carried by an actuator that is made of two portions that are selectively geared between them to selectively connect the crown to the hub.

A filtering pulley has a hub configured to be fixed to a shaft for rotation thereabout, a crown mounted coaxial and rotationally free on the hub, and a plurality of elastic groups arranged circumferentially with respect to the hub and to the crown and interposed, each, between a pair of first elements integral with the hub and between a pair of second elements integral with the crown. The first elements have at least two spokes, carried by an actuator that is made of two portions that are selectively geared between them to selectively connect the crown to the hub.