Release & Revision Control
Identify the approved drawing revision, sample reference and acceptance records for a repeat-order handover.
Review program qualificationMagnetic Rotor Assemblies
Engineered magnetic assemblies for motors, pumps and specialized industrial systems — from individual magnets to validated, ready-to-install rotors. Magnets bonded or insert-molded onto shafts and lamination stacks, magnetized, dynamically balanced, and flux-verified.
Product Range
Rotor Assemblies — Product Gallery
Product forms, uses and selection considerations. Final specifications are agreed for each project.
Sleeved Rotor
Retention reviewed for speed and mechanical loads.
Shaft & Bearing Interfaces
Rotor, shaft and mating interfaces defined together.
Bonded Rotor on Shaft
Integrated magnetic and mechanical motor subassembly.
Compact Segmented Rotor
Segmented construction for constrained assembly space.
Define the Rotor Acceptance Plan
The shaft datums, magnet locations and retention system define the inspection object. Review sleeve / bond interfaces with operating speed, temperature and assembly clearance.
Agree runout, balance planes and field-mapping conditions before release. Acceptance records must refer to the drawing revision and completed rotor configuration.
Review assembly quality controls- Maximum speed, overspeed requirement and balance grade
- Shaft datums, runout, concentricity and retention details
- Pole pattern, field/flux measurement location and acceptance limits
Assembly Process
From Components to Validated Assembly
Component Prep
Magnets, shafts and stacks received or produced; dimensions verified
Assembly
Bonding or overmolding under controlled process parameters
Magnetization
Magnetized in fixture; pole pattern and flux verified
Balancing
Two-plane dynamic balancing to specified grade
Testing
Final flux signature, runout and dimensional release
Engineering Controls
Assembly Quality Controls & Records
Magnetic field mapping
Review field shape and pole pattern against the agreed magnetic targets.
Dimensions & interfaces
Relate measured features to the datums and interfaces on your assembly drawing.
Magnetization
Radial, diametric, multi-pole or skewed — verified per pole on production assemblies.
Bonding
High-temp epoxy or overmolding; shear strength tested on production samples.
Balancing
Two-plane dynamic balancing to G2.5 (ISO 21940) standard, G1.0 on request.
Concentricity
Ground magnet OD and journals — 0.01 mm TIR runout reference, measured from the agreed datum axis.
Flux
Pole-resolved field or flux signature using the agreed fixture; measurement method and lot records defined in the inspection plan.
Documentation
Flux data, balance records and dimensional reports per the agreed inspection plan.
Inspection scope, acceptance criteria and the required records are agreed for each rotor design.
Assembly Anatomy
What Goes Into a Rotor Assembly
Every component, from the magnet grade to the balancing plane, is engineered and verified as one system.
●
→Magnets
NdFeB / SmCo / bonded — grade matched to temperature and performance spec
◉
→Shaft
Stainless, carbon steel or Alloy 42 — machined and ground to ±0.005 mm
◎
→Lamination Stack
Silicon steel 0.2–0.5 mm — die-cast or interlocked
◍
→Bonding / Overmold
High-temp epoxy, anaerobic or insert-molding — shear-tested
◌
→Sleeve (optional)
Stainless or carbon-fiber containment for high surface speeds
◆
Validation
Magnetization, flux signature, runout and dynamic balance
SELECTION GUIDEApplication selection notesExplore applications and requirements
Why Buy Complete Rotor Assemblies?
Magnet handling, bonding, magnetizing, and balancing are specialized processes — outsource them to us and focus on your motor winding and final assembly.
- ✓No magnet handling on your line — we deliver magnetized, balanced rotors — safety and quality improve immediately
- ✓100% flux verification — every rotor tested for pole flux and signature — acceptance limits and measurement conditions defined for the rotor
- ✓Dynamic balancing included — G2.5 as standard, G1.0 on request — residual unbalance accepted at the specified service speed
- ✓One supplier for magnets + machining — shafts, laminations, magnets, and coatings from a group quality framework
Applications
| Application | Typical Spec | Why This Material |
|---|---|---|
| BLDC Motor Rotors | N42SH arc segments on lamination stack | Efficient, compact motor cores |
| Pump Rotor Assemblies | Overmolded magnets on stainless shaft | Hermetically sealable wet rotor designs |
| Compressor Rotors | SmCo segments for high-temp | Refrigeration and HVAC compressors |
| Fan Rotors | Injection-molded ring magnets | High-volume cooling fan production |
| Automotive EPS Rotors | N48UH with high-retention adhesive | Steering systems needing extreme reliability |
Rotor Assembly Specifications
Typical capabilities — send your drawing for a specific quote.
| Parameter | Capability | Notes |
|---|---|---|
| Magnet materials | NdFeB N35–N54, SmCo 1:5/2:17, bonded NdFeB | Grade matched to your temp and performance spec |
| Shaft materials | Stainless 304/316/416, carbon steel, Alloy 42 | Machined and ground to ±0.005mm |
| Lamination stacks | Silicon steel 0.2–0.5mm | Die-cast or interlocked stacks |
| Bonding | High-temp epoxy (180°C), anaerobic, or overmolding | Shear-tested per lot |
| Magnetization | Radial, diametric, multi-pole, skewed | Verified per pole on 100% of production |
| Balancing | G2.5 standard, G1.0 available | Two-plane dynamic per ISO 21940 |
| Runout | 0.01mm TIR on magnet OD | Ground and 100% inspected |
Assembly Types
Assemblies We Build
Rotor Assemblies
Magnets on shaft / lamination stack — balanced and ready to install.
Halbach Arrays
One-sided, uniform-field arrays engineered to your air-gap target.
Overmolded Magnets
Insert-molded magnets for sealed rotors and harsh environments.
Couplings & Custom
Magnetic couplings and custom assemblies built to your drawing.
Quality Records
FAI / PPAP documentation is scoped to project requirements. Dimensional, magnetic and balancing records follow the agreed inspection plan.
View the five assembly quality controlsDesign Considerations
Send us your drawings — we'll flag these before quoting:
- ✓Magnet retention — surface speed, temperature, and interference fit determine whether adhesive alone suffices or a stainless sleeve is needed
- ✓Skew angle — the published 1–2 pole skew reference is not a universal design rule; evaluate skew with slot/pole combination, back-EMF, torque ripple and manufacturing cost
- ✓Sleeve for high-speed — Inconel or stainless sleeves contain magnet fragments above 100 m/s surface speed — we manufacture these in-house
What We Need to Quote
Provide any of these — the more complete, the faster and more accurate the quote:
- ✓Rotor drawing — magnet dimensions and grade, shaft dimensions, lamination stack details, tolerance callouts
- ✓Performance spec — torque, speed, back-EMF constant, temperature range — we can design the magnet circuit if you prefer
- ✓Volume — prototype quantity and annual volume for tooling amortization
- ✓Testing requirements — flux spec per pole, balancing grade, insulation class, and any OEM-specific standards
Process reference images are separated from the product gallery. They illustrate equipment and handling topics; they do not establish ownership of a facility, a customer delivery, or project-specific inspection results.
Factory Tour
Inside Magnetic Rotor Assemblies Manufacturing
Rotor programs combine automated magnet insertion, fixture-controlled assembly, final magnetization, dynamic balancing and protected tray packing.
4 process viewsProduct-specific manufacturing
1 inspection viewRelevant quality equipment
1 packing viewProduct-appropriate protection
End-to-end process visibilityManufacturing · inspection · packing documented in one focused route
Manufacturing processInspection & testingPacking & dispatch
Automatic Magnet Insertion
Enclosed equipment places magnet segments into rotor or stator fixtures.
Controlled Serial Assembly
Organized workstations maintain pole orientation, bonding and traceability.
Automated Rotor Assembly Line
Enclosed cells integrate magnet loading, magnetization and controlled rotor assembly for serial production.
Dynamic Balance Verification
Dual-plane balancing equipment checks residual unbalance before release.
Manufacturing, inspection and packing photographs for this product family.Equipment route varies by material and geometryRemote video inspection available before shipment
Illustrative Engineering Example — EV Rotor
An illustrative design review might consider an N38UH segmented rotor, a retention sleeve and dynamic balancing. Grade selection alone does not validate 180 °C continuous operation; the magnetic circuit, thermal duty and retention system require project-specific validation. This is not a documented customer delivery.
Frequently Asked Questions
Do you supply the lamination stack too?
Yes — we source or manufacture lamination stacks per your drawing, or accept customer-supplied stacks for assembly. Die-cast aluminum and interlocked stacks are both available.
How do you verify magnetization?
The inspection plan defines pole-resolved Hall-probe mapping, a suitable search-coil fixture or functional back-EMF testing as appropriate. A Helmholtz coil measures magnetic moment and alone does not resolve every pole of a multipole rotor. Agree fixture geometry, temperature, limits and shipment records before production.
Can you balance to tighter than G2.5?
We balance to G1.0 for high-speed applications like turbocharger and aerospace components. Achievable residual unbalance depends on rotor mass, service speed, geometry, correction planes and fixture repeatability; review these together for tighter requirements.
What's the typical lead time?
Prototypes: 2–4 weeks including magnet production. Volume production: 4–8 weeks depending on annual volume and tooling requirements. We hold safety stock for repeating programs.
Have an Assembly Drawing or BOM?
Send it to our team for engineering review and quotation — assembly drawings and BOMs welcome.