Essay On Gear Shaving

Gear shaving is basically a low pressure, free-cutting process. A helical gear-like cutter with closely spaced grooves extending from the tip to the root of each tooth, rotates with gear in close mesh in both directions during the shaving cycle. The centre distance between the gear and the cutter is reduced in small controlled steps to remove metal from the gear tooth surfaces till the final required size is achieved. The helix of the cutter is different from that of the gear to be shaved. Fig: Meshing of a Gear with a Shaving Cutter

For effective shaving, a pre-determined crossed-axes angle between the axes of the cutter and gear is important. The relative motion between the contacting tooth surfaces of the gear and the cutter, is composed of a rolling motion in the direction of the involute profile and a sliding motion along the length of the toothm

Again, the rolling motion along the involute is composed of a real rolling element and a sliding element. The rolling element is more prevalent near the pitch circle. However, as the contact of the tooth surfaces approaches the tops and roots of the teeth, the sliding element increases and the rolling element decreases accordingly. As the cutter rotates, the lands between the grooves act as cutting edges and remove

The cutter head is motor driven and can be swivelled to obtain the required crossed axes angle. Cutter head is mounted above the gear, so that there is no chance of dropping of a gear on cutter during loading/unloading. Chips fall down away from the cutter and do not clog the cutter serrations. The gear is loaded between live centres on the reciprocating work table. The reciprocating table is, again, mounted on a round table with sector gear and pinion to precisely set traversing angle for reciprocating motion with ease X - axis : Table Stroke