herringbone gear

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.
Also called double-helical gear.
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

British Dictionary definitions for herringbone gear

herringbone gear

noun
  1. a gearwheel having two sets of helical teeth, one set inclined at an acute angle to the other so that V-shaped teeth are formedAlso called: double-helical gear
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012