Abstract: A lightweight V-grooved pulley obtained from a metal plate and having a cylindrical member with one open end, the cylindrical member having a circumferential surface formed with at least one groove having a substantially V-shaped section is provided in which the material of the metal plate consists of an aluminum alloy containing 2 to 6 wt% of Mg, at least one of 0.005 to 0.2 wt % of Ti, and 0.0005 to 0.02 wt % of B, impurities containing not more than 0.2 wt % of Si, not more than 0.2 wt % of Fe, and not more than 0.5 wt % of Zn, and a balance consisting of Al and an inevitable impurity, and an anodized film is formed on a region including the groove. The material of the metal plate may additionally contain at least one element selected from the group consisting of 0.01 to 2.0 wt % of Cu, 0.02 to 1.0 wt % of Cr, and 0.01 to 0.3 wt % of Zr.

Abstract: A sheet metal poly-V pulley is made by forming a cup-shaped blank having a cylindrical wall with inner and outer peripheral surfaces, thickening the cylindrical wall by compressing the blank axially while rolling it, then rolling the thickened blank on shaped rollers to form corresponding inter-spaced inner and outer grooves. The outer grooves are deep V-shapes impressed with rollers; the inner grooves are shallow V-shapes formed by pressure against the surface of a rotary support for the cup shaped blank during rolling. The plurality of parallel V-shaped annular grooves in the outer peripheral surface receive poly-V belts, and the plurality of smaller V-shaped annular grooves on the inner peripheral surface are aligned between the outer partition walls and cause more-precise positioning of the outer grooves. Flared flanges are formed at opposite ends of the thickened portion projecting radially beyond the partition walls, the flanges having stepped, cut-out portions for receiving the edges of poly-V belts.

Abstract: A sheet metal poly-V pulley formed from a cup-shaped blank having a cylindrical wall with inner and outer peripheral surfaces, the pulley comprising: at least a portion of the cylindrical wall being thickened with material from the blank, the thickened portion having a plurality of parallel V-shape annular grooves in the outer peripheral surface, separated by parallel, annular partition walls, the alternating annular grooves and partition walls being adapted for receiving poly-V belts; the inner peripheral surface of the thickened portion having a plurality of small V-shape annular grooves arranged parallel to one another and centrally aligned with the partition walls of the outer peripheral surface; and, annular flanges at opposite ends of the thickened portion projecting radially beyond the partition walls, the flanges having stepped, annular cut-out portions to prevent contact between the pulley and lateral edges of poly-V belts.

Abstract: Improvements in a method of making a poly-V pulley from a metal plate which has V-shaped poly-V grooves formed in a cylindrical flange wall of a cup-shaped blank, by the application of pressing, compression and finishing processes to the blank. More particularly, the improvements reside in the compression process in which the opening end of the flange wall of a cup-shaped blank is fittingly held by a fitting groove which is formed in an upper peripheral edge of a lower rotary pressing form, the groove having a slope with a predetermined upward inclination in the radially inward direction toward the center of the form. Auxiliary rollers are pressed into groove valleys of the corrugated wall of the blank, and the blank is then axially compressed while rotating the blank, thereby converting the corrugated wall into a grooved wall having therein a series of V-shaped crests and valleys.

Abstract: A method for manufacturing a poly-V pulley comprising pre-forming the flange wall of a cup-shaped blank to have a corrugated cross section having a series of valleys formed around the outer circumference thereof, axially compressing the corrugated flange wall of the blank, and pressing a rotary forming roller against valleys formed around the outer circumference of the flange wall to form each of valleys to a predetermined V-groove. The axially compressing process is carried out keeping respective outer circumference of axially movable auxiliary forming rollers inserted into their corresponding valleys formed around the outer circumference of the flange wall of the blank.