Electric Motor Stator Lamination Stack

The stator lamination stack is a critical magnetic circuit component in electric motors, generators, and some transformers. It is manufactured by precisely stacking hundreds of thin, insulated electrical steel laminations to minimize eddy current losses. The stack is then bonded under high pressure to form a rigid, low-loss core that provides the stationary magnetic field path. Its precise geometry and material properties directly influence motor efficiency, torque, and thermal performance.

This component is used in the manufacture of electric motors, generators, and transformers. It is a device-level component, meaning it is a functional part of a larger assembly. The stack is made from non-oriented electrical steel (SiFe) with an insulation coating (C-5 or C-6). Key parameters include stack length (50–200 mm), lamination thickness (0.35–0.50 mm per IEC 60404-8-1), stacking factor (0.95–0.97), core loss at 1.5T and 50Hz (2.5–4.0 W/kg per IEC 60404-8-1), stacking pressure (2.0–4.0 MPa), slot number (24–72), outer diameter (80–400 mm), inner diameter (40–200 mm), tolerance on stack length (±0.1 mm per ISO 2768-m), flatness (0.05 mm per ISO 1101), insulation coating type (C5 per IEC 60404-1-1), maximum operating temperature (180°C per IEC 60085), and weight (5–50 kg).

When selecting a stator lamination stack, verify that the stack length, diameters, slot number, and tolerances match the motor design. Confirm the lamination material grade and insulation coating meet the required electrical and thermal performance. Check that the stacking factor and core loss values are within the specified range for the intended application. Ensure the stack's flatness and tolerance are suitable for the assembly process. Always verify model-specific values and standards with the legal manufacturer or supplier before procurement.

Thin, insulated laminations of electrical steel are stacked to form a solid core. The insulation between layers disrupts potential eddy current paths, reducing energy loss when the core is subjected to the alternating magnetic field from the stator windings. The stacking pressure ensures a rigid structure, while the stacking factor indicates the packing density of the steel. The geometry of the stack, including slot number and diameters, defines the magnetic circuit and influences motor performance.