Herringbone Gear

Also found in: Dictionary, Wikipedia.

herringbone gear

[′her·iŋ‚bōn ‚gir]
(mechanical engineering)
The equivalent of two helical gears of opposite hand placed side by side.

Herringbone Gear


a spur gear with V-shaped helical teeth. The mutual inclination of the tooth segments on opposite sides compensates the axial thrust produced by single helical gears. Herringbone gears afford smooth operation and increased load-carrying capacity, which are characteristic of helical gear transmissions in general. They are used in medium-size and large transmissions, including special transmissions operating at pitch-circle velocities up to 200 m/sec (turbine reduction gears).

Figure 1. Herringbone gears: (a) continuous-tooth type, (b) double helical gears, (c) two pairs of gears

Continuous-tooth herringbone gears (Figure 1,a) require special equipment to machine the teeth. Double helical, or conventional herringbone, gears (Figure l,b) have a gap, or groove, where the two sets of teeth meet; they may be made on ordinary gear-hobbing machines, but the width of the gear wheel must be increased by the width of the groove g. Transmission through two pairs of helical gears with opposed teeth (Figure 1,c) enables the space between the gears to be used for another transmission.

References in periodicals archive ?
Gears can be classified according to six criteria namely (1) according to configuration: external and internal gears; (2) according to axes of transmission: (a) for transmission between parallel shafts: straight toothed spur gear, single helical, and double helical or Herringbone gears, (b) for transmission between intersecting shafts: bevel gears (straight-tooth, spiral-tooth, zero-bevel, crown, and mitre type), (c) for transmission between non-parallel and nonintersecting shafts: spiral gears, hypoid gears, worm and worm wheel; (3) according to pattern of rotation: (a) rotation to rotation, (b) rotation to translation and vice-versa (i.