Patent ID: 6263571
Filing Date: 2001-07-24
Classification: B23F,F16H,Y10T

Abstract:
A method for manufacturing a toothed gear pair, each toothed gear having a variable diameter and variable pitch for providing a conjugate action therebetween, the method comprising the steps of:providing at least one numerically controlled milling machine having a frame, a machine spindle having selectively controllable rotation for rotatably carrying a workpiece to be machined, a carriage moveably carried by the frame for rotation and reciprocation thereof with simultaneous rotation of the workpiece, and a cutter carried by the carriage for cutting the workpiece in response to a preselected control input;providing at least one preselected control input to the numerically controlled milling machine, which input includes cutter movement commands for providing a conjugate movement between toothed gears of a toothed gear pair to be manufactured;mounting a first variable diameter shaped workpiece on the machine spindle of the at least one milling machine for rotation about an axis thereof, the first variable diameter shaped workpiece having a minor diameter end and an axially opposing major diameter end;cutting at least one groove into the first variable diameter shaped workpiece by reciprocating and rotating the cutter, while simultaneously rotating the first variable diameter shaped workpiece about the axis in response to the preselected control input for providing a groove which extends along the surface of the first variable diameter shaped workpiece between the minor and major diameter ends;rotating the first variable diameter shaped workpiece about the axis by one circular pitch, in response to the at least one preselected control input for providing a preselected number of teeth;repeating the groove cutting and rotating steps for forming a first variable diameter gear-forming tool having the preselected number of teeth positioned between the grooves cut therein and extending from the minor to the major diameter ends thereof, each of the preselected number of teeth having a forming edge thereon, each of the preselected number of teeth curved radially and axially outward while changing in pitch from the minor diameter end to the major diameter end;cutting at least one groove into a second variable diameter shaped workpiece having a minor diameter end and axially opposing major diameter end by reciprocating and rotating the cutter, while simultaneously rotating the second variable diameter shaped workpiece about an axis thereof in response to the preselected control input for providing a east one groove which extends along the surface of the second variable diameter shaped workpiece between the minor and major diameter ends thereof;rotating the second variable diameter shaped workpiece about the axis by one circular pitch in response to the preselected control input for providing a preselected number of teeth;repeating the groove cutting and rotating steps for forming a second variable diameter gear-forming tool having the preselected number of teeth positioned between the grooves cut therein and extending from the minor to the major ends thereof, each of the preselected number of teeth having a forming edge thereon, each of the preselected number of teeth curved radially and axially outward while changing in pitch from the minor diameter end to the major diameter end, the first and second variable diameter gear-forming tools resulting from the preselected control input for forming a variable diameter gear cutting pair operable in a gear forming machine for forming a variable diameter toothed gear pair;positioning the first variable diameter gear-forming tool on at least one gear-forming machine in a gear forming relationship to a third variable diameter shaped workpiece, from which third variable diameter shaped workpiece a first variable diameter toothed gear of the toothed gear pair is to be formed;forming the first variable diameter toothed gear;positioning the second variable diameter gear-forming tool on the at least one gear-forming machine in a gear forming relationship to a fourth variable diameter shaped workpiece, from which fourth variable diameter shaped workpiece a second variable diameter toothed gear of the toothed gear pair is to be formed; andforming the second variable diameter toothed gear, and thus the toothed gear pair, wherein each gear of the toothed gear pair has a variable diameter and variable pitch for providing a conjugate action therebetween.