One’s teeth on helical gears are cut at an angle to the facial skin of the apparatus. When two tooth on a helical equipment system engage, the contact begins at one end of the tooth and gradually spreads as the gears rotate, until the two teeth are in full engagement.

This gradual engagement makes helical gears operate a lot more smoothly and quietly than spur gears. For this reason, helical gears are found in virtually all car transmissions.

Due to the angle of one’s teeth on helical gears, they create a Sprocket thrust load on the apparatus when they mesh. Devices that use helical gears have bearings that may support this thrust load.

One interesting thing about helical gears is that if the angles of the apparatus teeth are correct, they could be mounted on perpendicular shafts, adjusting the rotation position by 90 degrees.