GB969320A - Improvements in and relating to means for generating involute gears - Google Patents

Abstract

969,320. Gear-grinding. P. H. CLEFF. Sept. 28, 1960 [Oct. 9, 1959], No. 34348/59. Heading B3K. A machine for generating involute gears using a continuously rotating work-table 11 and comprising a rotatable spindle 1 adapted to carry a generating wheel, e.g. a grinding wheel 2 having a flat or cone-shaped operative face of 150 to 179 degrees cone angle, mounted in a spindleholding member 3 and angularly movable therewith about a main pivot P axially normal to and co-planar with the generatrix g of the generating wheel and also parallel to the workpiece axis M, said pivot being journalled in a main slide 4 and slidable therewith in rectilinear guides 5 1 -5 2 so positioned that its rectilinear path coincides with a radial line through the work-piece centre, a retractor mechanism 22 actuating said main slide in such a way that during grinding the main pivot lies at the datum distance " R o +a o " from the gear axis but is withdrawn for indexing to a distance " R o +a o + Tooth Height " from said axis, and means for correlating the angular movements of the workpiece and spindle-holding member plus the rectilinear retractor movement of the main slide in such timed relation that from the said datum position and during the profile generating period with respect to one tooth flank of the workpiece, an angular movement - aGEN of the work-table is accompanied by an angular movement + #GEN of the spindle holding member such that αGEN=[(1+a 0 /R 0 ) sin #GEN - #GEN], and that from the end of said generating period a further angular movement of the worktable through - aINDEXING is accompanied by a rectilinear movement of the main pivot to a distance " R 0 +a 0 +Tooth Height " from the gear axis, an angular rotation - #GEN of the spindle-holding member and a rectilinear return movement of the main slide, and hence the main pivot, to its datum position " R 0 +a 0 " distant from the gear axis, said datum position now being with respect to another gear tooth flank either several pitches or, preferably, one pitch away from the first flank referred to above. The gear is rotated at a constant velocity while the generation, indexing and feed of a slide 6 take place. The slide 6 is moved on a column 9 by a screw 20 driven from a worm-shaft 14 through change gears 15. The column 9 is adjustable to-and-from the work by a screw 25. The table 11 is rotated by the worm-shaft 14 driven by a motor 16. The slide 6 carries a shaft 18, also driven through the change gears 15, to rotate a cam 19 controlling the angular movement of the pivot P through a lever 24. The slide 6 also carries the hydraulic retractor piston-rod 27. Modifications. The cam 19 may be replaced by an adjustable curve generating mechanism as described in Specification 898,626.