herringbone gear

American  

noun

1. a helical gear having teeth that lie on the pitch cylinder in a V -shaped form so that one half of each tooth is on a right-handed helix and the other half on a left-handed helix.

---

herringbone gear British  

noun

1. Also called: double-helical gear.  a gearwheel having two sets of helical teeth, one set inclined at an acute angle to the other so that V-shaped teeth are formed

---