Double Helical Gears

Double Helical Gear is of cylindrical form. It has two sections of teeth, right hand and the other left hand. They operate by engaging themselves simultaneously with the teeth of an identically designed mating gear.

In these Helical Gear the thrust loading is effectively eliminated by usage of two pairs of gears. The tooth angles are opposite to each other. This results in the cancellation of side thrust of one Gear by the other one. These opposite gears are made in a manner for having a space between the two opposing sets of teeth.

Types of Double Helical Gears
These helical gears are generally found to be of two kinds. One type is the one that has a gap between the helices. In the other one, opposite hand helices get cut without giving a gap. This is called the Herringbone Gears.

Both the type of helical gears uses a perfect combination of right and left hand helices. This makes the thrust load fully balanced. This balance is a conclusive advantage for selection of supporting bearings. Another advantage is lower loads on the gear reducer housing.

Characteristics of Double Helical Gears
The following are some of the prominent characteristics of a these helical gear:

Key Advantage of Double Helical Gears
These Helical Gear can offer the same type of advantage and operating smoothness as that of a single helical gear. Further, it offers the benefit of a greater strength in contact of the teeth and elimination of side ways force. Double helical gears provides an efficient and smooth transfer of torque and motion even at considerably high rotational velocities. As there is absence of axial thrust, helix angles are maintained around 30 degree, thereby offering the advantage of a large face overlap. Double helical gears give an efficient transfer of torque and smooth motion at very high rotational velocities.