Nkag siab txog kev khiav hauj lwm kub nce los ntawm Eddy tam sim no poob
Nyob rau hauv stator hlau nplaum (sib nqus mounted rau ntawm stator ntawm PM lub cev muaj zog lossis lub tshuab hluav taws xob), cov hlau nplaum sib txuas ntawm cov hluav taws xob zaus. Qhov no induces eddy tam sim no nyob rau hauv cov khoom siv hlau nplaum, ua kom sov. Rau 4-ncej lub cev muaj zog khiav ntawm 6000 rpm, hluav taws xob zaus yog 200 Hz. Eddy tam sim no poob nyob rau hauv cov khoom SmCo hlau nplaum tuaj yeem nce hlau nplaum kub los ntawm 30-60℃saum ambient, nyob ntawm cov hlau nplaum thickness thiab conductivity.
To mitigate eddy current heating, we segment SmCo magnets into thin slices (1-2mm thickness) insulated with epoxy coating between segments. This reduces eddy current loss by 80-90%. For high-frequency applications (>500 Hz), sintered SmCo nrog hluav taws xob resistivity 80-100 μΩ·cm yog siv (piv rau 50-60 μΩ·cm rau NdFeB).
Yog vim li cas SmCo yog Irreplaceable nyob rau hauv Extreme -Tsov Motors
NdFeB hlau nplaum saum toj no 220℃(txawm tias muaj EH lossis AH qib) raug kev txom nyem sai sai irreversible demagnetization vim diffusion ntawm qhov hnyav tsis tshua muaj lub ntiaj teb cov ciam teb. SmCo, nrog Curie kub ntawm 750-800 degree, qhia tsis muaj theem hloov hauv qab 400 degree. Cov ntawv thov uas txib SmCo suav nrog:
Aerospace actuators: nruam 250℃kev ua haujlwm, muaj sia nyob ntawm 350℃rau 30 feeb.
Downhole drilling motors (roj & roj): ambient 200℃+ tus kheej - cua sov rau 280℃.
Industrial induction heating rollers: magnet temperatures >250 degree.
Siab - spindle motors ceev (20,000-60,000 rpm): cua kub cua sov + eddy tam sim no.
Hauv cov cheeb tsam no, siv NdFeB yuav xav tau cov kua txias txias lossis ua rau muaj kev puas tsuaj loj hauv cov xuab moos.
Defining Reversible Temperature Coefficients thiab Irreversible Losses
Rov qab poob: qhov hloov pauv hauv Br nrog qhov kub thiab txias uas rov qab los thaum txias. SmCo's (kub coefficient ntawm Br) yog -0.03 txog -0.04% / degree, lub ntsiab lus nce 200℃txo Br los ntawm 6-8%. Qhov kev poob no tau rov qab los ntawm chav tsev kub.
Irreversible poob: poob mus tas li vim kev hloov pauv ntawm metallurgical lossis ib nrab demagnetization. Rau SmCo hauv qab 350 degree, irreversible poob yog negligible (<0.5% per 1000 hours). For NdFeB at 200°C (grade N40UH), irreversible loss can exceed 10% per 1000 hours.
Selecting the correct SmCo grade: SmCo 2:17 (e.g., Sm2Co17, grades 26-32 MGOe) has higher Br and better thermal stability than SmCo 1:5 (18-22 MGOe). For continuous 300°C, use Sm2Co17 with Hcj > 25 kOe at 20°C, derated to >12 kOe ntawm 300 degree.
Aligning Motor Thermal Design nrog Txoj Cai Magnet Qib
Lub cev muaj zog thermal tsim yuav tsum suav rau:
Maximum nruam hlau nplaum kub (ambient + kub nce).
Peak luv luv -lub sij hawm kub (hnyav tshaj lossis cov khoom hauv chaw nres tsheb).
Txoj kev ua kom txias (cua cua, lub tsho dej, roj tsuag, lossis passive).
Peb muab kev xaiv qib matrix:
| Max Magnet Temp (degree) | Pom zoo SmCo Qib | Hcj min @ temp (kOe) | Hom Tsav Hom |
|---|---|---|---|
| 150-200 | SmCo 1:5 (qib 18) | 5-8 | Kev lag luam dav dav, tus nqi -sensitive |
| 200-280 | Sm2Co17 (qib 24) | 8-12 | Siab -torque servo, traction |
| 280-350 | Sm2Co17 (qib 28 nrog V) | 12-18 | Aerospace, downhole, lub luag haujlwm hnyav |
| >350 | AlNiCo (ntxiv) | N/A (tsis muaj kev pheej hmoo demag) | Tshwj xeeb (tsis muaj SmCo saum 350℃txuas ntxiv) |
Rau cov tuam txhab lag luam uas xav tau SmCo stator hlau nplaum lossis ua kom tiav rotor sib dhos nrog SmCo arcs, thov mus saib peb cov nplooj ntawv Stator Magnet thiab Samarium Cobalt Magnets ntawm peb lub vev xaib. Peb muab tag nrho segmented hlau nplaum kom txo tau eddy tam sim no poob.
Txhawm rau thov kev simulation thermal thiab qib kev pom zoo rau koj lub cev muaj zog - suav nrog qhov xav tau qhov kub thiab txias, lub voj voog ua haujlwm, thiab txoj kev ua kom txias - hu rau peb pab pawg tsav tsheb.
Cov lus nug nquag
Q: Cov hlau nplaum SmCo puas tuaj yeem ua kom nruj zoo li ± 0.03mm?
A: Yog, tab sis SmCo nyuaj thiab nkig ntau dua NdFeB. Peb siv pob zeb diamond sib tsoo log. Cia siab tias 10-15% ntau dua machining nqi dua NdFeB. Tolerances ± 0.05mm yog tus qauv; ± 0.02mm muaj nrog tus nqi hwm.
Q: Puas SmCo hlau nplaum xav tau txheej rau kev tiv thaiv corrosion?
A: SmCo muaj corrosion kuj zoo heev nyob rau hauv qhuav los yog me ntsis humid ib puag ncig. Rau cov tshuaj tsuag ntsev los yog tshuaj lom neeg, peb pom zoo kom nyias Ni-Cu-Ni (10-15μm) los yog parylene txheej. Feem ntau cov motors uas muaj cov vaj tse kaw yuav tsum tsis muaj txheej.
Q: Lub sijhawm ua haujlwm rau kev cai SmCo arc ntu (OD 80mm, ID 70mm, ntev 50mm) yog dab tsi?
A: 15-20 working days for prototype quantities (10-50 pcs). 25-30 working days for production (>500 pcs). Tus nqi cuab yeej: $ 800-1200 rau ntu tuag.
