Herringbone gear

A herringbone gear, a specific type of double helical gear, is a special type of gear that is a side to side (not face to face) combination of two helical gears of opposite hands.From the top, each helical groove of this gear looks like the letter V, and many together form a herringbone pattern (resembling the bones of a fish such as a herring). Unlike helical gears, herringbone gears do not produce an additional axial load.