| 摘要 |
1280162 Gear cutting; indexing GLEASON WORKS 1 Oct 1969 [1 Oct 1968] 48233/69 Headings B3B and B3K A gear cutting machine has a workhead assembly 40 slidably arranged on upstanding sidewall members 36 the work spindle 42 axis being arranged generally vertically and below a horizontally disposed cradle 32 and face-milling cutter holder 34. The work spindle is arranged to be pivotable within a limited range from the vertical to an inclined position. As shown, Fig. 1, the machine may be double, i.e. providing two cutting stations 24 and two such double machines with suitable work transfer and conveyer means may be arranged to provide automatic machining of gear blanks at two roughing stations and two finishing stations (Fig. 4, not shown). For the cutting of spiral bevel and hypoid gears the cradle 32 and work spindle are driven by an hydraulic motor 118, the relative rotation of the cradle and spindle being determined by a generating train 52, 54, ..., 88, 92. The speed and direction of motor 118 are regulated by control valve means actuated differentially from a control cam 162 on the one hand and the generating train on the other hand. Thus cam 162 controls the displacement of a screw and nut assembly 166, 168 to displace a control valve actuating lever while at the same time screw 168 is rotated by a suitable gearing from the drive shaft 120 in a direction to move axially relative to the nut 166 in the opposite direction and thus to restore the control valve to its neutral position. Thus a given rotation of cam 162 produces a fixed proportionate rotation of the cradle and correspondingly of the work spindle. Where tooth cutting occurs in both directions of roll the ratio of roll between the cradle and work spindle may be altered slightly in one direction by means of a cam 206 driven through gearing 200, 202, 204 from the drive shaft 120 the cam 206 being adapted to shift in its axial direction a drive worm 54 for the cradle. Axial motions of the cradle may be effected either by a feed cam 156, e.g. for indexing or by a helical motion mechanism in which drive is taken from the cradle via gear 190 and used to drive a cam which shifts the cradle axially for axial feed during cutting of a gear. An indexing mechanism 96 is provided comprising an hydraulically reciprocable rack 98 operation of which (and simultaneously of an hydraulically actuated clutch 104, 105) produces a predetermined increment of rotation of a differential spider 116 which in turn produces a desired rotation of the work spindle relative to the cradle. A locking pawl 110, normally engated with a locking disc 112 in the index mechanism is released for the indexing operating. |
