Internal gears are the ones with the teeth formed on the inner surface of a cylinder or cone. Internal gears mesh with spur gears. There are two types of tooth shape, one being parallel and the other one with a helix in respect to the axis. However gears with teeth parallel to the axis have higher demand.

Planetary gear mechanism
The most popular application for internal gears is usage for planetary gear trains or gear reducers composed of a carrier, several spur gears, called planet gears and a sun gear in the center, rotating inside an internal gear.
(PDF : “Calculation for Planetary gear mechanism from the KG Gears Catalog)

Internal Gear Design – 3D CAD models and 2D CAD drawings
Now, you can verify the dimensions of our standard Internal Gears through our PDF catalog or our Gear Selector provided by Part Community. Free CAD data is available on the website. Click the logo below to access the Internal Gear Selector.

Quotation of Standard Internal Gears
Please request your Quotations for Internal Gears though our “Request For Quotation” page.

Internal Gear Modification
We can customize our standard Internal Gears to suit your specific applications, please consult with us. We are offering gear modification services. Please check the details and examples of modifications at our “Gear Modification” page.

BRASS INTERNAL GEARS	STEEL INTERNAL GEARS
Material : C3604B Module : 0.5, 0.8 Number of teeth : 60 – 120	Material (ISO) : S45C Module : 1.0 Number of teeth : 60 – 120
Outside diameter is manufactured to a h8 tolerance to provide quick installation without having to perform any modification.	Outside diameter is manufactured to a h8 tolerance to provide quick installation without having to perform any modification.
PDF CATALOG	PDF CATALOG