Helical gear

The leading edges of the teeth are not parallel to the axis of rotation, but are set at an angle. Since the gear is curved, this angling causes the tooth shape to be a segment of a helix. The angled teeth engage more gradually than do spur gear teeth. This causes helical gears to run more smoothly and quietly than straight-cut gears. Helical gears also offer the possibility of using non-parallel shafts.

See Also

• Bevel gear