CUSTOM MOTOR DEVELOPMENT / OEM & R&D
A distinct topology / application-led development
For precision-motion OEMs and research teams evaluating an ironless active winding, start with the allowable disturbance torque and thermal duty. Removing stator teeth changes the magnetic circuit, conductor support and drive requirements; it does not eliminate every source of torque ripple.
THE PROGRAM STARTS HERE
01
Removing ferromagnetic stator teeth removes that tooth-interaction cogging mechanism. Commutation, current ripple, magnetic harmonics, sensor error and bearings still affect motion. Specify unpowered detent and powered ripple tests separately.
02
A wound air-core stator and an etched PCB stator need different fabrication inputs. Review conductor loss, insulation, potting, stiffness and the complete path to the cooling boundary.
03
Request winding resistance and inductance definitions, current-loop behavior and measured PWM ripple. The inverter, switching strategy and any filtering need to match the actual winding.
INPUTS / INTERFACES / OWNERSHIP
These are the decisions to scope before a quotation. Feasibility, engineering deliverables, sample cost, tooling and recurring production terms follow the agreed requirements.
| Decision | Iron-cored yokeless | Ironless active stator |
|---|---|---|
| Active stator | Segmented ferromagnetic teeth and coils; no common stator yoke | Supported copper winding or PCB traces; no active ferromagnetic teeth |
| Magnetic circuit | Core permeability and saturation enter the design | Effective nonmagnetic gap includes winding and support thickness |
| Motion quality | Cogging and powered ripple require design and measurement | Tooth cogging mechanism removed; powered ripple still requires measurement |
| Thermal path | Coil insulation, core / potting and cooling interfaces | Conductor, support / resin / laminate and cooling interfaces |
| Drive review | Constants and current limits matched to the design | Inductance, PWM ripple and sensing especially relevant |
| Procurement scope | Core, wound segments, kit or housed assembly | Wound stator or PCB fabrication, rotor–stator kit or motor program |
WORKED EXAMPLE / ASSUMED INPUTS
Illustrative balanced three-phase winding: at 10 A phase RMS and 0.20 Ω resistance per phase at the stated temperature, DC-resistance copper loss is 60 W. At 20 A it becomes 240 W if resistance is held constant. Removing a stator core does not remove this heat.
P_copper = 3 × I_phase,RMS² × R_phase
Arithmetic example only, with wye-connected phase definitions. Actual resistance rises with winding temperature; AC conductor effects and inverter ripple add loss. These are not measured losses or a motor rating.
APPLICATION-SPECIFIC DUTY
Provide low-speed torque, encoder resolution, allowable ripple and disturbance bandwidth. Measure torque at the shaft with a defined controller configuration rather than relying on the topology label.
Specify the mechanical duty, noise, temperature and cleaning environment. Device qualification, traceability and validation requirements must be agreed with the responsible manufacturer.
Define inertia, reversal duty, cable routing and thermal paths. Space-environment or vacuum use adds separate material, heat-rejection and qualification work; no flight heritage is claimed.
AGREE ACCEPTANCE BEFORE SAMPLES
START WITH A NON-CONFIDENTIAL BRIEF
Send the requirements and quantities first. Request an NDA before sharing detailed proprietary CAD. The review defines feasibility, deliverables and responsibilities before pricing or timing is confirmed.
Use the inquiry form, or contact us directly with your duty cycle, package, cooling and quantity requirements.
ENGINEERING & PROCUREMENT
No. A yokeless segmented-armature motor can retain ferromagnetic stator teeth while removing the shared stator yoke. An ironless active stator removes those teeth. They are different magnetic and thermal designs.
Not necessarily. The term here refers to the active stator winding region. Rotor back iron or other magnetic support structures may remain, so the complete cross-section must be reviewed.
No generic zero-ripple guarantee is made. Eliminating stator-tooth cogging does not eliminate current ripple, commutation harmonics, sensor error or mechanical disturbances. Agree separate detent and powered tests.
No. A supported air-core wire winding is another approach. PCB artwork, layer stack and vias differ from wire, insulation, winding fixtures and potting; quote and validate each process separately.
Compatibility is not automatic. Review winding inductance, current measurement, switching strategy, control bandwidth, feedback and heating under the intended operating cycle.
No released motor model or approved dimensional file is offered on this page. Share the package requirements first. Any later interface drawing must carry its own revision, units and use limitations.
