OEM Custom Magnetic Coupling Inner Rotor

Permanent Magnet Drive Couplings — Hermetic, Torque-Dense, Custom-Built

Both Inner & Outer Rotors | Mature Magnetic Circuit Engineering | In-House Production | Export-Ready

Why Magnetic Couplings — And Why the Inner Rotor Matters Most

A magnetic coupling does not look like a coupling at all. There is no gear mesh, no belt, no shaft-to-shaft contact. The drive motor's torque is transmitted across a solid metal barrier by magnetic force alone — the inner rotor turns, the outer rotor follows, the barrier stays sealed. No mechanical seal. No leak path. No scheduled seal maintenance.

Inside that barrier, the inner rotor is the component doing the work. Its magnet grade, pole count, hub material, and balance grade determine how much torque the coupling can transmit, at what speed, at what temperature, and for how long. A coupling is only as good as its inner rotor.

Since 2011, FAIZEAL has engineered custom permanent-magnet inner and outer rotors for magnetic couplings in chemical pumps, pharmaceutical mixers, sterile fluid transfer, semiconductor wet benches, and high-pressure process systems. Both halves of the magnetic circuit are produced, assembled, and tested on our own floor.

What Is a Magnetic Coupling Inner Rotor?

A magnetic coupling inner rotor (also called mag-drive inner rotor, permanent magnet drive rotor, or inner magnet assembly) is the driver-side rotating component of a magnetic coupling. It is mounted on the drive-motor shaft, carries a ring of high-energy permanent magnets arranged in a multi-pole pattern, and produces the magnetic field that crosses the containment can to drive the outer rotor on the driven shaft.

Typical construction of a FAIZEAL inner rotor:

u Sintered NdFeB (or SmCo) arc segments arranged in a radial multi-pole or Halbach array

u Precision-ground 316L stainless steel or 4140 alloy hub, bored to customer spec (press-fit, keyed, splined, or with locking feature)

u Single-piece or two-piece (clamshell) hub design for assembly and service access

u Epoxy-filled magnet pockets (potted construction) for chemical and moisture resistance

u Optional outer banding sleeve (stainless or titanium) for high-rpm or hazardous-duty service

u 100% dynamic balance to ISO 1940 grade G2.5 / G6.3 per order specification

Every dimension, every pole count, every grade is engineered to your torque and slip-speed target. We do not ship catalog rotors.

How a Magnetic Coupling Works — The Physics in One Paragraph

The drive motor turns the inner rotor. The inner rotor's permanent magnets produce a strong, rotating magnetic field. That field crosses a non-magnetic containment can (the hermetic barrier between the motor side and the process side). On the other side of the can, the outer rotor's magnets lock to the rotating field and follow it. Because the inner and outer magnet rings are designed to the same pole pitch, the two rotors run synchronously: zero slip, zero contact, zero wear. Torque is transmitted through the can by magnetic force. The can stays sealed for the life of the equipment.

Where FAIZEAL Magnetic Coupling Rotors Are in Service

u Canned motor pumps and magnetic drive pumps (API 685, ASME B73.3) for hydrocarbon, acid, alkali, and solvent transfer

u Hermetic agitators and mixers for pharmaceutical, biotech, and sterile API production

u Sealless centrifugal pumps for semiconductor wet process (HF, SC1, SC2, NMP, IPA)

u Food and beverage processing — sanitary couplings for syrups, dairy, oils, and CIP-cleaned lines

u Cryogenic pump and compressor couplings for LNG, LPG, and air-separation plants

u High-temperature hot-oil and molten-salt pumps in solar and chemical plants

u Hazardous-area ATEX / IECEx equipment where zero spark risk is mandatory

u Nuclear and primary-loop sample transfer where leak detection is non-negotiable

If your process fluid must never touch a mechanical seal, your process is a magnetic coupling problem — and we have already built a version of the rotor you need.

Full-Custom Engineering — Both Halves of the Circuit

Many suppliers will sell you an inner rotor. Some will sell you an outer rotor. Few will engineer, balance, and ship both halves of a magnetic coupling as a matched set, with the containment can, the sleeve bearings, and the dimensional report all on one engineering thread. FAIZEAL does all of it, in-house.

Size — No Upper Limit

u No upper size limit. Inner rotors from Ø20 mm precision instruments to Ø600 mm+ heavy-duty process pumps

u Outer / inner diameter, axial length, hub bore, and pole count are all per your drawing

u Need an odd aspect ratio or a non-standard pole pitch for an existing OEM pump? Tell us the OEM model and the magnetic circuit spec — we reverse-engineer the geometry and ship a drop-in

Magnet Grade & Pole Count — Sized to Your Torque Target

u Magnet grade: N35 to N52 for NdFeB; SH / UH / EH for high-temperature and high-coercivity duty

u Sm2Co17 (SmCo) for sustained operation above 200 C, or for oxidizing chemistry where NdFeB coatings are at risk

u Pole count: 4 / 6 / 8 / 12 / 16 / 24 / 32 poles — or any non-standard count you need

u Halbach array option (single or dual layer) for ~20-30% higher torque density in the same envelope

Hub Material & Mechanical Interface

u 316L stainless steel — the workhorse for chemical and pharma service

u 2205 / 2507 duplex stainless for chloride-rich and offshore duty

u 17-4PH precipitation-hardened stainless for high-torque, high-rpm applications

u 4140 alloy steel for cost-driven high-torque service

u Titanium (Gr2 / Gr5) for low-mass and high-corrosion service

u Hub bore: press-fit, keyed (DIN 6885 / ANSI B17.1), splined, or with proprietary locking feature

u Clamshell (two-piece) hub available for in-situ magnet service without removing the shaft

Containment Can (Optional)

u 316L SS, Hastelloy C-276/C-22, titanium, Inconel 625/825 — supplied as deep-drawn or welded assemblies

u Wall thickness optimized for minimum eddy-current loss while meeting pressure and burst requirements

u Welded can with full penetration weld, leak-tested helium or pressure-decay

u Electropolished internal surface for sanitary service

Balance, Coatings, and Sealing

u Dynamic balance to ISO 1940 G2.5 / G6.3 / G16 per rotor mass and service speed

u Epoxy fill (potted construction) for magnet pocket sealing against process fluid ingress

u Outer banding sleeve (316L or titanium) for high-rpm containment of magnet fragments in the event of a rotor failure

u Surface finish: passivation, electropolishing, PTFE coating, or multi-layer coating stacks for chemical exposure

u 100% dimensional and magnetic inspection with full traceability per batch

Duty-Specific Variants We Regularly Deliver

u High-temperature rotors up to +200 C (EH-grade NdFeB) or up to +350 C (SmCo)

u Low-temperature / cryogenic rotors for LNG and air-separation (-196 C)

u Sanitary / CIP-cleanable rotors for food, beverage, and pharmaceutical service

u ATEX / IECEx certified construction for Group II Category 2 / 3 hazardous areas

u High-purity clean-room assembly and packaging for semiconductor and biotech service

Inside the Magnetic Circuit — Why Our Rotors Transmit More Torque

We treat every rotor as a designed magnetic system, not a stock part. The decisions that matter are made before the first arc segment is ground:

u Magnet grade selection: N35 to N52 (NdFeB) or Sm2Co17, chosen for the required torque per magnet gram and the operating temperature

u Pole count optimization: more poles give smoother torque and lower ripple, fewer poles give higher per-pole torque and a thicker can for pressure

u Back-iron (hub) design: hub wall thickness and material matched to the flux path so the magnetic circuit is not saturated at the bore

u Air-gap budget: the gap across the can is the single biggest variable in torque — we design the rotor pole pattern to maximize torque at your actual gap, not at zero gap

u Eddy-current loss: high-rpm can-side losses are real; we spec the can wall thickness and material to balance pressure rating vs. heating

u Temperature stability: HcJ, urec, and irreversible loss budget computed for your max operating temperature, with margin for short-term excursions

End-to-End In-House Production — Magnet, Rotor, Optional Can

We do not outsource the steps that define your coupling's performance:

u Sintered NdFeB (and SmCo) production, grain-boundary diffusion, and pulse magnetization through controlled, audited supply chains

u Multi-axis grinding of arc segments to +/-0.03 mm (precision +/-0.01 mm)

u CNC machining of hubs in 316L, 2205, 17-4PH, 4140, and titanium — boring, key-cutting, balancing features

u Magnet pocket epoxy fill (potted construction) and banding sleeve installation

u Containment can supply: deep-drawn and welded, in 316L / Hastelloy / titanium / Inconel, with full penetration weld and leak test

u 100% dynamic balance on in-house balancer to ISO 1940 G2.5 / G6.3 / G16

u Pulse magnetizer up to multi-Tesla, with field-mapping for Halbach and high-pole-count builds

u Full traceability: per-rotor batch record, magnet lot, hub material cert, balance report, and optional magnetic flux map

Technical Specifications

All values are typical ranges — every parameter is customized on request.

Why Engineers Choose FAIZEAL for Magnetic Coupling Rotors

1.  10 years of magnet-component engineering — NdFeB, SmCo, Halbach arrays, magnetic couplings, rotor assemblies, and pot magnets. We do not subcontract magnetic know-how.

2.  Both halves of the circuit in-house — inner rotor, outer rotor, and the containment can, on one engineering thread

3.  Custom is our default — every rotor BOM is open to your torque, speed, temperature, and chemistry constraints

4.  Materials matched to the fluid, not the catalog — 316L, duplex, 17-4PH, Hastelloy, titanium, Inconel, all in-house machinable

5.  No upper size limit — from Ø20 mm precision rotors to Ø600 mm+ heavy process rotors

6.  Standards-ready documentation — API 685, ASME B73.3, ISO 5199, ATEX / IECEx, REACH / RoHS / CE

7.  Export-ready logistics — DDP / FOB / EXW, NDA-friendly engineering workflow, sample and production lead times to your project schedule

Frequently Asked Questions

What is the difference between a magnetic coupling inner rotor and outer rotor?

The inner rotor is mounted on the drive (motor) shaft, inside the containment can. The outer rotor is mounted on the driven (pump / mixer) shaft, outside the can. Both rotors carry permanent magnets arranged at the same pole pitch; the inner rotor's rotating field crosses the can and locks the outer rotor into synchronous rotation. We manufacture both halves as a matched set, on one engineering thread.

Can you reverse-engineer an existing OEM coupling rotor?

Yes. Send us the OEM model number, the existing rotor OD / ID / length, and (if you have it) the magnet grade and pole count. We will back-propose a drop-in replacement rotor, including a magnetic circuit spec and a balanced matched set if you need both halves.

NdFeB or SmCo for my application?

NdFeB is the default — higher torque density, lower cost. SmCo is the choice when (a) sustained operating temperature is above ~180 C, (b) the process chemistry is strongly oxidizing and there is risk to NdFeB coatings, or (c) the customer requires the higher Curie temperature for safety margin. We help you choose per your service.

What is the maximum torque your rotors can transmit?

Torque scales with rotor OD, axial length, magnet grade, and pole count. We have delivered matched sets from sub-1 N.m (instrument pumps) to several thousand N.m (large process pumps). Tell us your torque target and your envelope; we will back-propose the rotor geometry.

Do you supply the containment can as well?

Yes. We supply containment cans in 316L, Hastelloy C-276 / C-22, titanium, and Inconel 625 / 825. The can is supplied either as a deep-drawn component, a welded assembly, or fully integrated with the rotor build. We balance, leak-test, and document each can with the rotor batch.

What about balance and tolerance?

Every rotor is dynamically balanced to ISO 1940 G2.5 (precision) / G6.3 (general) / G16 (cost-driven). Magnet pocket tolerances are held to +/-0.03 mm on standard builds and +/-0.01 mm on precision builds. We ship a balance report and a CMM dimension report with every batch on request.

Can you do ATEX / IECEx certified rotors?

We supply ATEX / IECEx-ready construction (spark-safe materials, banding sleeve, certified material certificates) and the full documentation pack. We are not a notified certification body, but we provide the engineering record and test data your notified body requires.

What are your typical lead times?

Prototype / sample rotor: 10-20 working days after drawing freeze. Production: 20-45 working days depending on volume, material, and can supply. SmCo and Halbach orders may run longer — we confirm a date at quotation.

Can you keep spare rotors for our fleet?

Yes. We offer scheduled batch-rotation stock for OEM customers, with a 5-year material and process reproducibility guarantee per fleet reference.

Get a Custom Quote — Fast

Send us:

u Outer diameter x inner bore x axial length (or your existing rotor drawing / OEM model)

u Required torque, max speed, and slip tolerance (synchronous mag-drive assumed)

u Operating temperature range and process fluid / chemistry

u Hub material preference (316L / duplex / 17-4PH / titanium / 4140)

u Containment can requirement: supplied by FAIZEAL, supplied by customer, or no can needed

u Pole count, magnet grade preference (or let us specify)

u Balance grade (G2.5 / G6.3 / G16) and any certification pack (ATEX, food-grade, nuclear)

u Quantity and target delivery date

We typically return a feasibility and indicative pricing note within 2 working days, and a firm quotation within 5-7 working days.

FAIZEAL — magnetic coupling inner rotors and matched outer rotors, engineered for zero-leak, zero-contact, zero-maintenance service.