What Determines Brushless DC Motor Tooth Flux Density?
The Bottom Line (Key Takeaway): When designing high-performance motors, accurately calculating the Brushless DC motor tooth flux density is critical for establishing the working magnetic flux. Quantitative analysis reveals a clear rule: tooth flux density is heavily dependent on tooth width and magnet remanence, whereas structural factors like punching sheet length and material grade have surprisingly minimal impact under normal conditions.
Quantitative Analysis: How Different Variables Affect Tooth Flux Density
To simplify your motor design and judgment process, we have tested and analyzed the mutual relationship between the motor magnet, stator, punching sheet data, and the resulting tooth magnetic induction intensity.
Here are the practical engineering conclusions separated by their level of impact:
Variables with Direct & Significant Impact:
Tooth Width: There is a strict mathematical relationship here. The tooth width is strictly inversely proportional to the tooth flux density, and the error margin is incredibly small.
Magnet Material: The tooth flux density is directly proportional to the magnet’s remanence (residual magnetism). When upgrading or changing magnet materials, the resulting flux density changes reliably within the design compliance rate.
Variables with Minimal or No Impact:
Punching Sheet Length: If the punching sheet profile remains unchanged, altering the length results in almost no change to the tooth flux density.
Punching Sheet Material: Under the condition that the tooth flux density remains unsaturated, switching the material of the punching sheet does not significantly alter the flux density.
Proportional Scaling: If the shape of the punching sheet magnet is enlarged proportionally, the overall motor magnetic circuit performance, air gap flux density, and tooth flux density remain almost completely unchanged.
Other Shape Variations: Minor changes to other shapes of the punching sheet do not have a significant impact on the final tooth flux density.
Surface-Mounted Magnet Shapes: Whether you use different shapes of surface-mounted magnets, the tooth flux density, motor torque constant, and rated operating point remain basically identical.
Engineering Conclusion: Understanding these simple relationships provides immense help in practical Brushless DC (BLDC) motor design. By knowing exactly which parameters to tweak (like tooth width) and which to ignore (like proportional scaling), engineers can optimize magnetic circuits much faster and with higher precision.
