Helical Gear And Spur Gear Properties.

Helical or "dry-fixed" gears offer improved characteristics over spur gears. The tip of the tooth is not parallel to the axis of rotation, but is at an angle. Because the gears are bent, this angle causes the tooth shape to become a segment of the propeller. Helical gears can be engaged in parallel or intersecting directions. The first refers to when the axes are parallel to each other. This is the most common address. In the latter, the shaft is not parallel, and in this configuration the gear is sometimes referred to as "skew gear". Angled teeth work smoother and quieter as they mesh more gradually than straight gear teeth. With parallel worm gears, each pair of teeth first touches a single point on one side of the sprocket. The moving contact curve gradually increases to the maximum across the tooth surface and retracts until the tooth breaks contact at a single point on the opposite side. In spur gears , the teeth suddenly cause tension and noise with line con...