54 kNm/m³ nominal density in one prototype
A 2025 experimental study reports this nominal torque density for its specific coaxial gear. It is not a universal range or a quote specification.
Buy Magnetic Gear
Check a coaxial pole-count ratio, then prepare an engineering RFQ. This quick check does not size or certify a complete gearbox.
Supply scope: This page starts a custom engineering or sourcing inquiry for magnetic components or a defined assembly. It is not a catalog checkout for a complete magnetic gearbox; confirm complete-assembly supply scope in the RFQ. For array-only requirements, see the Halbach array RFQ checklist.
Evidence before estimates
What the available performance evidence says
A recent experimental result is useful as a reference point, but one prototype cannot predict another gear’s rating.
87–97% measured efficiency
The same prototype’s measured efficiency varied with the tested operating conditions. Speed, load, losses and the complete mechanical assembly matter.
Temperature is grade-specific
A material name alone does not set a safe operating limit. Check the selected grade and magnetic circuit against the worst-case temperature and opposing field.
Evidence checked October 4, 2026. Lovato et al., “Experimental Analysis of a Coaxial Magnetic Gear Prototype,” Machines 13(8), 716 (2025), reports measurements from one prototype and notes limits to generalization. Read the experimental paper. Temperature selection should be checked against the actual supplier grade data, such as NdFeB grade data and SmCo grade data.
How the coaxial pole-count check works
In a conventional coaxial field-modulated layout, the stationary ferromagnetic pole pieces modulate the field between two permanent-magnet rotors. The calculation uses pole pairs, not individual magnet blocks.
Reading the result
Let p1 be the inner, high-speed rotor pole pairs and p2 the outer, low-speed rotor pole pairs. For this topology, the modulator pole-piece count is Ns = p1 + p2. With the modulator held stationary, the ideal speed reduction magnitude is p2 / p1; the two rotors turn in opposite directions.
Ns = p1 + p2 · Reduction = p2 / p1
This relation does not determine torque, dimensions, air gap, losses, dynamic response, thermal margin or manufacturability. Those require a defined geometry and engineering analysis.
Explore axial Halbach array manufacturingCompare the system around the gear
Magnetic transmission changes where contact and losses occur; it does not remove the need to compare the complete drive at its real duty point.
| Decision factor | Magnetic gear | Mechanical gear | What to verify |
|---|---|---|---|
| Torque and size | The cited study reports a nominal 54 kNm/m³ for its tested coaxial prototype; other designs need their own analysis. | Capacity depends on gear type, stages, size and duty; no single range is comparable to every magnetic design. | Required output torque, speed, envelope and duty cycle. |
| Contact and lubrication | Torque crosses a magnetic gap without meshing gear teeth; bearings, seals and supports can still wear. | Meshing teeth need a lubrication and maintenance plan appropriate to the selected gearbox. | Maintenance access, sealing, bearing life and lubricant constraints. |
| Efficiency | One prototype measured 87–97% across tested conditions; speed and load changed the result. | Losses depend on stages, speed, lubrication and loading; compare measured or modeled values for the duty point. | A matched input/output speed and torque map, including part-load operation. |
| Overload | Magnetic pull-out can limit transmitted torque, but slip and re-engagement transients still need evaluation. | Protection depends on gear strength, drive controls and any torque limiter or clutch. | Peak torque, fault response, recovery behavior and downstream loads. |
| Material and environment | Magnet grade, magnetic circuit, corrosion protection and thermal margin are coupled. | Materials, lubrication, seals and cooling set operating limits. | Worst-case temperature, fluid or vacuum exposure, and qualified component data. |
Main magnetic-design risks
- Air-gap and runout errors can reduce transmitted torque or cause mechanical interference; tolerances depend on the design.
- Field modulation can create losses and heat in magnets and conductive or ferromagnetic parts; thermal analysis and suitable lamination may be required.
- Magnetic pull-out is not a substitute for a system-level overload protection and transient review.
A useful buying decision
Keep a magnetic gear on the shortlist when contactless torque transfer or lubricant isolation solves a real system constraint. Compare a mechanical alternative when cost, compactness, mature supply and known duty-life dominate. Ask suppliers for equivalent duty-point evidence before choosing.
Have a target duty point or drawing? Ask engineering which magnetic component or assembly scope fits your RFQ.
Discuss your RFQFrom concept to RFQ
What to send for a useful review
The configurator summary is a starting point. Drawings and operating conditions let an engineer judge which magnetic components or assembly scope may fit.
HalbachMagnet’s contact route starts an engineering inquiry; it does not imply that every request includes a complete gearbox. Confirm product scope, supply boundary and validation plan in the RFQ.
Review the manufacturing and assembly capabilities for the work HalbachMagnet performs on custom magnetic components and assemblies.
| RFQ item | Why it matters |
|---|---|
| Target torque, speed and duty cycle | Defines the operating point, overload and loss envelope. |
| Rotor dimensions, air gap and interfaces | Sets magnetic geometry, tolerance and assembly constraints. |
| Temperature and environment | Narrows magnet grade, coating, sleeve, seal and cooling requirements. |
| Quantity and requested supply scope | Separates prototype, magnet or array supply, integration, testing and production quotation. |
Magnetic gear buying questions
Ready to discuss a magnetic gear concept?
Send your pole counts, target torque and operating conditions. Include a drawing if available so the engineering team can confirm component scope and the next validation step.
Contact EngineeringLast reviewed: October 4, 2026. Project prices and performance are confirmed only after requirements review.