Patent ID: 8555505
Filing Date: 2013-10-15
Classification: F16H,G01B,Y10T

Abstract:
1. A flat wave gear device, comprising: a D-side rigid internally toothed gear; an S-side rigid internally toothed gear disposed in parallel in a coaxial state with the D-side rigid internally toothed gear; an annular flexible externally toothed gear disposed in a coaxial state within the D-side and the S-side rigid internally toothed gears; and a wave generator for causing a cross-section of the flexible externally toothed gear given perpendicularly with respect to an axis thereof to flex elliptically and the resulting shape to rotate; a number of teeth on the D-side rigid internally toothed gear being the same as a number of teeth on the flexible externally toothed gear, and a number of teeth on the S-side rigid internally toothed gear having 2n more teeth, n being a positive integer, than the number of teeth on the flexible externally toothed gear; the flat wave gear device having a tooth profile derived from the following method: determining a rack-approximated movement locus of the flexible externally toothed gear with respect to the S-side rigid internally toothed gear accompanying rotation of the wave generator; wherein the method for setting the tooth profile in the flat wave gear device further comprises: determining the movement locus using formula (1); determining an evolute of the movement locus using formula (2); and determining the radius of curvature ρ