Patent ID: 8435145
Filing Date: 2013-05-07
Classification: F16H,Y10T

Abstract:
1. A method for making a sprocket with reduced noise and vibration for a chain and sprocket drive comprising: selecting a uniform chain having pins interconnected by links, each of the pins having a central axis and a chain pitch defined as a distance between the central axis of adjacent pins, the chain pitch being constant; selecting a uniform sprocket having a plurality of uniform teeth and uniform tooth gaps spaced about the periphery of the sprocket, each of the uniform tooth gaps being located between adjacent uniform teeth, each of the uniform tooth gaps having a tooth gap radial location defined as a distance between the center of the uniform sprocket and a point along the uniform tooth gap closest to the center of the uniform sprocket in a radial direction, each uniform tooth gap having the same tooth gap radial location; forming a uniform trapezoid with a base having a length equal to the distance between a center of a pin in a first uniform tooth gap and the center of a pin in a fourth uniform tooth gap of a set of four consecutive uniform tooth gaps of the uniform sprocket, the top and legs of the uniform trapezoid being equal in length to the chain pitch; forming a quadrilateral by moving vertices of the uniform trapezoid while maintaining the length of each side; and making a random sprocket having at least one set of four consecutive random tooth gaps by assigning each vertex of the quadrilateral to a center of one of four consecutive pins in the uniform chain and positioning the four consecutive pins in the four consecutive random tooth gaps.