Axial Flux Motor Stator Core for In-Wheel Hub Motors & Electric Two-Wheelers Custom Wound Core

Engineering Overview: Axial Flux Stator Cores for In-Wheel Hub Motors & Electric Two-Wheelers

Shunge Steel manufactures custom wound axial flux stator cores specially designed for in-wheel hub motors, direct-drive electric motorcycle powertrains, high-performance e-bikes, and light electric vehicles (LEVs). In hub motor applications, eliminating transmission gears and packaging the motor directly inside the wheel rim demands maximum torque density, compact axial depth, and minimal unsprung weight.

By winding continuous high-grade non-oriented silicon steel into an optimized disc ring and forming deep radial slots via high-precision CNC laser cutting, we deliver stator cores that provide intense magnetic flux utilization, exceptional starting torque, and superior cooling characteristics without costly stamping dies.

Key Technical Advantages for In-Wheel Hub Drives

• Massive Starting & Climbing Torque Density: The disc-shaped axial flux design maximizes the active magnetic surface area at a larger effective air-gap radius, generating substantially higher continuous and peak torque for steep hill climbing and heavy load acceleration.
• Minimized Unsprung Mass & Wheel Weight: Eliminating bulky radial back-iron significantly reduces total wheel hub weight, dramatically improving electric motorcycle handling dynamics, suspension responsiveness, and vehicle range.
• Superior Thermal Dissipation in Sealed Hubs: Direct axial thermal conduction and exposed planar surface area facilitate rapid heat transfer from copper windings to the outer wheel casing, preventing overheating during prolonged high-load cruising.
• Zero Tooling Investment for Varied Rim Sizes: Whether designing for 10-inch scooter rims, 14-inch moped wheels, or 17-inch motorcycle rims, outer diameter (OD), inner diameter (ID), and slot profiles are customized directly via CNC laser programs without expensive stamping mold lead times.

Technical Specifications & Parameter Matrix

Electric Two-Wheeler & Light EV Applications

Our custom wound hub motor cores are built to withstand rigorous road shock, heavy vibration, and demanding duty cycles across diverse light electric mobility sectors:

• High-Performance Electric Motorcycles: Delivers high peak torque for rapid acceleration and sustained highway speeds without multi-speed transmissions.
• Urban E-Bikes & Electric Mopeds: Compact axial width fits within standard bicycle dropout widths (135mm / 150mm) and scooter rear swingarms.
• Electric Cargo Trikes & Delivery Scooters: High continuous torque capacity supports heavy payload delivery and frequent stop-and-go hill starts.
• Electric Golf Carts & Industrial AGV Wheels: In-wheel direct drive eliminates differentials, saving chassis space and increasing payload efficiency.

Customization & OEM/ODM Engineering Workflow

We collaborate closely with electric vehicle motor designers to deliver tailored stator core solutions:

1. Application & Drawing Review: Provide your target wheel rim size, power/torque requirements, and 2D/3D CAD drawings (STEP, DWG, DXF).
2. Electromagnetic & DFM Evaluation: Our technical team optimizes core strip winding tension, slot geometry, and cooling pathways.
3. Rapid Prototyping: Complete prototype cores manufactured and shipped within 7–12 working days without stamping tooling delays.
4. Validation & Testing: Full CMM dimensional checks, slot alignment inspection, and core loss verification prior to volume production.

Precision Manufacturing & Quality Control

Shunge Steel maintains rigorous quality control across every manufacturing stage to guarantee road-grade reliability:

• Tension-Monitored Disc Winding: High-precision winding ensures consistent stacking density and eliminates radial delamination under heavy torque.
• High-Speed Clean Laser Slotting: Inert gas-assisted laser cutting creates burr-free slot edges, preserving inter-laminar insulation resistance.
• Thermal Stress-Relief Annealing: Vacuum protective atmosphere annealing restores virgin magnetic permeability and eliminates mechanical cutting stress.
• Dynamic Geometry Inspection: Comprehensive CMM verification for outer diameter roundness, inner bore concentricity, and axial flatness.

Packaging & Global Logistics Protection

To ensure cores arrive in pristine condition ready for automated winding and assembly:

• VCI Anti-Rust Barrier Bags: Each core is coated with protective anti-rust oil and hermetically sealed with vapor corrosion inhibitor packaging.
• Custom Shockproof EPE Foam: Form-fitted heavy-duty foam inserts protect laser-cut teeth against handling shock and drop impacts.
• Export-Grade Wooden Crates: Shipped in robust, fumigation-free wooden crates compliant with international air and ocean cargo standards.

Frequently Asked Questions (FAQ)

Q1: Why is an axial flux motor stator core superior for in-wheel hub motors compared to a radial flux core?
A: Axial flux motors produce significantly higher torque density because their active magnetic area is located at a larger diameter near the wheel perimeter. Furthermore, their ultra-flat pancake geometry fits neatly inside wheel rims without requiring transmission gearboxes, reducing unsprung weight and improving vehicle dynamics.

Q2: Can you accommodate large center bore (ID) requirements for hollow-axle hub motor designs?
A: Yes. Because our cores are wound from electrical steel strip and laser-slotted, we can customize the inner diameter to match your exact hollow axle, wheel bearing, or internal brake mounting dimensions.

Q3: What electrical steel thickness should be selected for electric motorcycle hub motors?
A: For urban e-bikes and standard speed scooters (operating below 1000 RPM), 0.35 mm or 0.50 mm electrical steel provides excellent torque at high cost efficiency. For high-speed electric motorcycles operating at higher electrical frequencies, 0.20 mm or 0.27 mm thin-gauge steel is recommended to minimize high-speed eddy current losses.

Q4: Do design changes require purchasing new stamping tooling?
A: No. All slot features, skew angles, and diameters are generated by CNC laser cutting. You can iterate and refine your electromagnetic design without paying for costly stamping dies or waiting for tooling lead times.

Q5: What is the typical lead time for prototype hub motor cores?
A: Prototype orders are typically manufactured, inspected, and dispatched within 7 to 12 working days following CAD drawing confirmation.