Low noise pulley

A method of constructing a low noise pulley comprising the steps of:

• constructing a hub, including an outer hub, and an outer rim;
• constructing a plurality of arms radiating outward from the outer hub to the outer rim;
• selecting a pitch sequence describing a pseudo-random pattern of relative spacings between proximate pairs of arms wherein the selected pitch sequence includes at least three successive relative spacings, and the three successive relative spacings differ from each other by at least four percent of the smallest relative spacing;
• and
• arcuately spacing the radially outermost ends of the plurality of arms about the outer rim of the pulley in accordance with the selected pitch sequence.

A pulley for an endless belt drive system, the pulley comprising:

• a hub including an outer hub;
• an outer rim;
• and
• first and second pluralities of arms extending radially outward from the outer hub to the outer rim, the first and second pluralities being equal in number;
• wherein the radially outermost ends of proximate pairs of arms in the first and second pluralities of arms are, respectively, arcuately spaced apart about the outer rim according to a pitch sequence describing a pseudo-random pattern of relative spacings the selected pitch sequence includes at least three successive relative spacings, the selected pitch sequence includes at least three successive relative spacings, and the three successive relative spacings differ from each other by at least four percent of the smallest relative spacing;
• and
• wherein the arms of the second plurality of arms are angularly offset from the arms of the first plurality of arms about the axis of rotation of the pulley.