Patent ID: 6449846
Filing Date: 2002-09-17
Classification: B23F,F16H,Y10T

Abstract:
A method for manufacturing a variable-diameter toothed gear having a variable pitch for providing a conjugate action with an associated variable-diameter toothed gear, the method comprising the steps of:providing a 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 a 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 milling machine for rotation about an axis, the first variable diameter shaped workpiece having a minor diameter end and an axially opposing major diameter end; cutting one groove into the 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 preselected control input for providing a preselected number of teeth; repeating the groove cutting and rotating steps for forming a variable diameter gear-forming tool having the preselected number of teeth positioned between the grooves and extending from the minor to major diameter ends thereof, each of the teeth having a forming edge thereon, each of the teeth curved radially and axially outward while changing in pitch from the minor diameter end to the major diameter end; positioning the variable diameter gear-forming tool on a gear-forming machine in a gear forming relationship to a second variable diameter shaped workpiece, from which second variable diameter shaped workpiece a variable diameter toothed gear is to be formed; and operating the gear forming machine for forming the variable diameter-toothed gear.