Patent ID: 6827666
Filing Date: 2004-12-07
Classification: F16H,Y10S,Y10T

Abstract:
A method of selecting gear ratios for use in a motor vehicle transmission having a plurality of gears ranging between a low gear and a high gear, which comprises:determining a low gear ratio for the low gear, and a high gear ratio for the high gear; determining a total ratio spread by dividing said low gear ratio by said high gear ratio; determining a number of gear ratios; determining a number of ratio steps by subtracting one from said number of gear ratios; determining a ratio variable by raising said total ratio spread to a power inverse of said number of ratio steps; determining values for said ratio steps by creating a geometric sequence having a plurality of terms representing each of said respective ratio steps such that a ratio of any two consecutive ratio steps is a common percent constant; and successively determining a gear ratio for each gear in the transmission between the low gear and the high gear by dividing a gear ratio previously determined for a next lower gear by a ratio step plus one for the next lower gear so as to have uniformly progressive ratio steps, wherein narrow step ratios provide for a smaller skip shift index and wide step ratios provide for a larger skip shift index.