The gear blank before the unmachined tooth shape is called a tooth blank.
According to different processes of forming the tooth blank, it is divided into a cast tooth blank, a forged tooth blank and a welded tooth blank.
Standard installation of the tool: When machining the gear with a rack tool or a gear insert, if the index circle of the gear blank is perpendicular to the reference line of the rack tool, or if it is tangent to the indexing circle of the insert, then the blank and the tool are The standard installation of the tool is called relative to the mounting position. The gears that are machined and manufactured by the standard are standard gears.
Displacement of the tool: When the rack tool is used to form a gear, if the reference line (center line) of the rack is not tangent to the index circle (node circle) of the gear blank, the mounting position of the tool relative to the blank is called the tool. Displacement installation. The radial separation amount mx of the tool reference line and the blank indexing circle is called the displacement amount, and x is called the displacement coefficient. The gear that is cut and mounted is a displacement gear.
Rack standard installation: Rack mounting generally refers to the installation of the rack tool relative to the blank when the rack tool is machining the gear. The so-called rack standard installation is the installation position of the center line of the rack tool and the blank index circle (node circle), otherwise the rack is not standard installation. The gears that are standardly mounted on the rack are standard gears. Gears that are machined in a non-standard installation are gears.