First-Order Proportional Modification Parameters for Spiral Bevel Gears Manufactured by Spread Blade Method

The proportional modification parameters are useful for modifying the tooth form errors of spiral bevel gears. Based on the mathematical model for calculating the machine setting parameters and according to the relative position relationship between cutter and workpiece and the curvature and vector of calculation point, the formulae for calculating the first-order proportional modification parameters for gears machined by spread blade method was deduced. The proportional modification parameters can make the pressure angle or spiral angle of the concave flank and the convex flank produce uniform change and difference change. The formulae is verified by experiment on CNC spiral bevel gear grinding machine and M&M sigma 7 gear measuring center.