GB894522A - Improvements relating to gear generating machines - Google Patents

Abstract

894,522. Gear-cutting. GLEASON WORKS. Dec. 18, 1959 [Dec. 19, 1958], No. 43108/59. Class 83 (3). [Also in Group XXXVII] In a gear-generating machine, the generating train is driven by a motor 19, Fig. 2, the speed of which is varied by a cam 104, Fig. 4, driven by the motor. A gear blank G, Fig. 1, is mounted on a head 15 adjustable in the direction of the blank axis 14, on a base 16 swinging on a slide 17 about an axis 18 intersecting the axis 14 and the tool-cradle axis 12. The slide 17 is adjustable in the direction of the axis 12. The motor 19 rotates the work-spindle 13 and oscillates the cradle 11 through rate-of-roll change gears 22, a cam 28, a bell-crank 29 and a connecting rod 31, the movement of the cradle during cutting being in a constant proportion to that of shafts 24, 27 but being faster and at a varying rate during a return roll. A cam 32 moves the work to-and-from cutting position. Index change gears 38 in the drive to the workspindle cause the blank to be rotated one or more teeth between the cutting operations. The planing tools T, T<SP>1</SP> are reciprocated by a motor 42 through a shaft 45, coaxial with the cradle, and crank-shafts 53. In the cutting of a tooth space, if the rate of roll is constant, more cutting is done at the beginning of a cut than when the tool is in a central position, as illustrated in Fig. 5 by the tool positions a, b, c, d, e after equal intervals of time. To produce a more uniform cutting rate, the speed of the generating motor 19 is therefore gradually increased as the tools move between positions a and e by adjusting an auto-transformer to vary the D.C. voltage applied to the motor 19. The adjustment is made by the cam 104, Fig. 4, rotated from a worm 101, Fig. 2, and rocking a lever 106 geared to the transformer shaft 112. The less the curvature of the tooth profile, the greater should be the acceleration imposed on the rolling motion. The machine may be modified by having a rotary cutter or an intermittent indexing mechanism.