Generally, there are gear teeth, tooth slots, end faces, normal surfaces, tooth top circle, tooth root circle, base circle and graduation circle.
Gear tooth is called tooth for short. It is every convex part of gear used for meshing. These convex parts are generally arranged radially. The teeth on the matched gear contact each other, which can make the gear continuously meshed and operated.
The tooth slot is the space between two adjacent teeth on the gear; the end face is the plane perpendicular to the axis of the gear or worm on the cylindrical gear or worm.
The end face is the plane at both ends of the gear.
The normal plane refers to the plane perpendicular to the tooth line of the gear.
Addendum circle refers to the circle at the tip of the tooth.
Dedendum circle refers to the circle at the bottom of the groove.
The generating line of the involute formed by the base circle is a pure rolling circle.
The dividing circle is the reference circle for calculating the geometric dimension of the gear in the end face.