In This Article
Key Takeaways
- ◆Specify the active faces, material orientation and magnetization pattern for the actual topology.
- ◆Select segment directions from the three-dimensional harmonic field and current paths.
- ◆Set flatness and parallelism from the complete assembled air-gap tolerance stack.
- ◆Select the grade using the actual hot demagnetization curves, the magnetic circuit working point and the worst opposing field. A suffix is a nominal material class, not a guaranteed motor temperature limit or a chemical recipe. Mainrich’s sintered NdFeB range is N30 to N56, with no AH grades. The top grade depends on the temperature series: N56, N54M, N52H, N52SH, N50UH and N45EH. Grades up to N52SH can be made without a Chinese export licence, so we offer those first; UH and EH grades need a licence, applied for per order. Confirm the grade, suffix, geometry and production route for each drawing. This summary does not offer every combination; grades outside it in educational examples are not Mainrich supply offers.
- ◆No fixed torque-density gain, machining premium or lead-time adder applies to every axial-flux design.
Start from the rotor geometry
An axial-flux motor uses an active air-gap field principally along the shaft axis. The magnet shape and orientation depend on the rotor topology. Draw the active faces, pole pattern and mounting datums explicitly. Radial-flux machines also have different magnet orientations, including IPM arrangements; it is incorrect to assume every radial-flux magnet is magnetized along the same geometric direction.
Define each magnet shape
For a sector or ring segment, give inner and outer radii, included angle, thickness, edge treatment and the active pole face. Rectangular or other shapes can be evaluated if the motor design supports them. Do not infer a compulsory shape or a fixed cost premium from the axial-flux label.
Choose segmentation using the field model
Time-varying fields can induce currents within conductive magnets. Determine the relevant three-dimensional paths for the actual stator, winding and drive. Compare cuts and insulation in the same model. No universal 60–80% loss reduction or fixed preference for a cut direction follows from the topology alone. See the segmentation guide.
Control the assembled air gap
Include disc runout, bearing location, magnet thickness, flatness, coating, bond line and hot deformation. State the finished measurement datums and acceptance limits. A geometric change in gap does not imply the same percentage change in flux or torque. Confirm manufacturing capability for each critical feature.
Evaluate the hot material
Select the grade using the actual hot demagnetization curves, the magnetic circuit working point and the worst opposing field. A suffix is a nominal material class, not a guaranteed motor temperature limit or a chemical recipe. Mainrich’s sintered NdFeB range is N30 to N56, with no AH grades. The top grade depends on the temperature series: N56, N54M, N52H, N52SH, N50UH and N45EH.
Grades up to N52SH can be made without a Chinese export licence, so we offer those first; UH and EH grades need a licence, applied for per order. Confirm the grade, suffix, geometry and production route for each drawing. This summary does not offer every combination; grades outside it in educational examples are not Mainrich supply offers.
The cooling path and magnet losses must come from the actual design; do not add a generic temperature increment or automatically move one suffix higher.
Prepare the RFQ
Send the geometry, magnetic requirements, duty cycle, assembly method and inspection plan. Specify the coating formulation, thickness on each face, edge coverage, substrate preparation and cure. Agree a corrosion test method, exposure duration and acceptance endpoint for the actual part, then request its report.
Salt-spray hours are not a service-life guarantee. Agree tooling, sample quantity, inspection and production milestones in the quotation. Export release depends on any required authorization. No standard prototype quantity or fixed delivery interval is promised here.
Frequently Asked Questions
Are axial-flux motors always better?
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Compare complete designs at matched operating points. No universal power-density or efficiency percentage is established here.
What grade should an axial-flux motor use?
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Select the grade using the actual hot demagnetization curves, the magnetic circuit working point and the worst opposing field. A suffix is a nominal material class, not a guaranteed motor temperature limit or a chemical recipe. Mainrich’s sintered NdFeB range is N30 to N56, with no AH grades. The top grade depends on the temperature series: N56, N54M, N52H, N52SH, N50UH and N45EH. Grades up to N52SH can be made without a Chinese export licence, so we offer those first; UH and EH grades need a licence, applied for per order. Confirm the grade, suffix, geometry and production route for each drawing. This summary does not offer every combination; grades outside it in educational examples are not Mainrich supply offers.
Can I use rectangular magnets?
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For a sector or ring segment, give inner and outer radii, included angle, thickness, edge treatment and the active pole face. Rectangular or other shapes can be evaluated if the motor design supports them. Do not infer a compulsory shape or a fixed cost premium from the axial-flux label.
How should I specify magnetization?
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Define the material orientation, active faces and pole pattern, and confirm the magnetizing fixture and assembly sequence with the supplier.
What is the cost premium?
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Request a drawing-specific quotation for the chosen geometry, tolerance and route. This article establishes no standard premium.
Send the axial-flux rotor drawing, thermal duty and assembly requirements for a part-specific quotation.
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