Motor Stator & Rotor Core Lamination Stacking Calculator

4. Engineering Notes & Physics Specifications

Electric Motor Stator and Rotor Core Stacks are assembled from micro-thin electrical steel sheets (silicon-iron alloys with inorganic C3/C5 coating or self-bonding varnish) to channel magnetic flux while suppressing eddy current losses ($P_{\text{eddy}} \propto t^2 \cdot f^2$).

• Stacking Factor ($k_{\text{fe}}$): Varies with sheet thickness: $\approx 0.95$ for 0.20 mm sheets, $\approx 0.965$ for 0.35 mm sheets, and $\approx 0.98$ for 0.50 mm sheets. Active magnetic length is $L_{\text{iron}} = k_{\text{fe}} \cdot H$.
• Interlocking Dimple Strength: Mechanical punch bosses press into mating recesses with shear retention $F_{\text{shear}} = n_{\text{boss}} \cdot \pi \cdot d_{\text{boss}} \cdot t \cdot \tau_{\text{yield}} \cdot \mu_{\text{press}}$.
• Thermal HAZ Permeability Degradation: Fiber laser cutting creates a heat-affected zone ($d_{\text{HAZ}} \approx 0.08 - 0.15\text{ mm}$) that elevates hysteresis losses around narrow tooth tips. Post-cut stress-relief annealing (750°C in inert $N_2$) recovers base permeability.