PR-104 SPUR GEAR AND SPIRAL GEAR

Spur gears or straight-cut gears are the simplest type of gear. They consist of a cylinder or disk with the teeth projecting radially. These gears can be meshed together correctly only if they are fitted to parallel shafts.

Spiral or helical gears offer a refinement over spur gears. 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. Helical gears can be meshed in parallel or crossed orientations.

These models help students to comprehend the specific benefits of different types of gears and their intended applications.