C-type lamination refers to a specific shape or design of stator or rotor lamination used in electric motors, particularly universal motors, small AC motors, or certain DC motor designs. The name "C-type" comes from the general shape of the lamination core—it resembles the letter "C" when viewed from the side, where the open side of the "C" represents the slot opening for winding insertion. Unlike the more commonly used circular or E/I core laminations, C-type laminations are open-frame and used when there's a need for simplified coil winding or specific magnetic path requirements. These are more common in frame-type or bracket-type stators, especially in applications where the winding needs to be placed around the core instead of inserted into inner slots.
Features of C-Type Laminations
Shape and Structure:
One side of the lamination is open, allowing easy access for winding.
Usually made from cold-rolled, non-oriented electrical steel to minimize core loss.
Punching Process:
C-type laminations are manufactured through progressive or compound die punching.
The punching process must ensure minimal burrs, tight tolerances, and consistent dimensions to maintain performance.
Applications:
Found in low-voltage motors, fan motors, grinders, or appliances where compact size and ease of assembly are priorities.
Suitable for manual or semi-automatic winding processes.
Advantages:
Easier coil winding compared to traditional closed slot stators.
Simplified assembly process.
Lower tooling cost in some cases.
Design Considerations:
Magnetic circuit must be carefully designed to compensate for the air gap at the opening of the “C”.
Core losses and eddy currents must be controlled through proper lamination thickness and insulation coating.