Compound Dies in Electrical Lamination Manufacturing

Compound dies are specialized tooling systems used in high-precision stamping operations, allowing multiple actions—such as punching, blanking, and forming—to occur in a single press stroke. In the context of motor lamination manufacturing, compound dies are essential for producing intricate and consistent shapes with tight tolerances, particularly for stator and rotor assemblies.

Stator Die

A stator die is a type of compound die designed specifically for stamping stator laminations—the stationary part of an electric motor. This die precisely punches the outer profile, inner bore, and slot shapes of the stator from electrical steel sheets. Key features of stator dies include:

• High concentricity and dimensional control to ensure proper fit and magnetic performance.

• Can include interlocking or notching features for stacking laminations.

• Often designed for progressive or compound action to complete blanking and slot punching in one pass.

Rotor Die

A rotor die is used for stamping rotor laminations, the rotating component of electric motors. Like stator dies, rotor dies are crafted to maintain high accuracy and consistency across large production runs. They may feature:

• Compound action to punch the rotor’s outer profile, slots, and center hole in a single stroke.

• Customization for various rotor bar shapes and slot geometries depending on motor design.

• Precision alignment to ensure balanced rotation and efficient performance.

Notching Die

A notching die is used for selectively cutting slots or notches into the inner or outer periphery of stator or rotor laminations—typically one slot at a time. This method is ideal for lower volume production or prototyping. Key points include:

• Often used in tool room or low-volume environments.

• Allows flexibility in slot shape and position.

• Can be manual or semi-automatic depending on production scale.

While notching is slower than compound die stamping, it provides a cost-effective solution for customized or developmental motor designs.

Window Die

A window die is specifically engineered to punch window openings or cutouts within the stator or rotor lamination. These “windows” are often used to allow the winding process or improve magnetic flux flow. Features of window dies include:

• Accurate placement of non-standard cutouts within the lamination profile.

• Often integrated as part of a compound or progressive die setup.

• Useful in the production of specialized or high-efficiency motor cores.