| Involute Gear Cutting | Gear Manufacturing | Gear Hobbing | Gear Milling | Gear Shaping| Gear Planing |

» Suwa Precision Home
» Gear Hobbing Specialist
» Miniature Gear Pumps


Resource articles on gears and splines:
» Power Transfer Gears and Shafts
» Gear Geometry and Formula
» Splines Shafts

Gear Tooth Production

Modern gear teeth have an involute profile. These gear teeth are made by the following processes:

• Forming the gear teeth by using milling
• Generating the gear teeth by gear planing or rack
• Generating the gear teeth by gear shaping
• Generating the gear teeth by gear hobbing

Gear milling

Milling is a form-cutting process limited to making single gears for prototype or very small batches of gears as it is a very slow and uneconomical method of production. A involute form-milling cutter, which has the the profile of the space between the gears, is used to remove the material between the teeth from the gear blank on a horizontal milling machine. The depth of cut into the gear blank depends on the cutter strength, set-up rigidity and machineability of the gear blank material.

Gear Planing or Rack Generation

This is used for mid volume production. A rack, which may be considered to be a gear of infinite radius, is used as the cutter. It is constructed of hardened steel with cutting edges round the teeth boundaries. The rack which is given a reciprocal laterial motion equal to the pitch line velocity of the gearis slowly fed to the slowly rotating gear blank. In this way, the material between the teeth is removed and the involute teeth are generated.

Gear Shaping

The cutter is a circular pinion-shaped cutter with the necessary rake angles to cut as shown. Both the gear blank and cutter are set in a vertical plane and rotated such as that the two are like gears in mesh. Gear shaping is faster than gear planing because the cutting process is continuous and the cutter does not have to be stepped back.

This is the most versatile gear cutting process which could produce internal and external gears, close-coupled cluster gears and splines too.

Gear Hobbing

This is the most productive of all the gear production processes. However, it can only be used for producing spur gears and worn gears. It cannot be used to cut internal gears and it cannot work up a shoulder.

The hob is used to generate the involute teeth here. The hob is basically a straight cylindrical tool around which a thread with the same cross section as the rack tooth has been helically wound. This hob is then rotated with the gear blank fed onto the hob according to the depth of cut. The helix pattern of hob as it rotates is the same as that of the rack moving laterally.

Mizuhata Seiki`s Gear Manufacturing Process

Over 6 decades since 1944, Mizuhata Seiki specializes in gear hobbing of precision miniature custom gears and turned parts for gearbox, gear pump, spindle motors, miniature gear motor and precise positioning used in movement watches, IT electronic products and medical devices.