I kēia mau lā, ke ulu nei ka ʻenehana i ke alapine kiʻekiʻe a me ka wikiwiki kiʻekiʻe, ua lilo ka eddy i kēia manawa o nā magnet i pilikia nui. ʻOi aku kaNeodymium Iron Boron(NdFeB) a me kaSamarium Cobalt(SmCo) magnets, ʻoi aku ka maʻalahi o ka hopena e ka wela. Ua lilo ka eddy i kēia manawa i pilikia nui.
ʻO kēia mau au eddy e hopena mau i ka hoʻoulu ʻana i ka wela, a laila hoʻohaʻahaʻa i ka hana i nā kaʻa, nā mea hana, a me nā mea ʻike. Hoʻopau pinepine ka ʻenehana anti-eddy o nā magnet i ka hana o ka eddy current a i ʻole ke kāohi i ka neʻe ʻana o ka au i hoʻokomo ʻia.
Ua hoʻomohala ʻia ʻo "Magnet Power" i ka ʻenehana Anti-eddy-i kēia manawa o NdFeB a me SmCo magnet.
Ka Eddy Currents
Hoʻokumu ʻia nā kahawai Eddy i nā mea conductive i loko o ke kahua uila a i ʻole ke kahua magnetic. Wahi a ke kānāwai o Faraday, ʻo ka hoʻololi ʻana i nā māla magnetic e hoʻohua ai i ka uila, a ʻo ia hoʻi. I ka ʻoihana, hoʻohana ʻia kēia kumumanaʻo i ka hoʻoheheʻe metallurgical. Ma o ka induction medium-frequency, hoʻoulu ʻia nā mea conductive i loko o ka crucible, e like me Fe a me nā metala ʻē aʻe e hoʻohua i ka wela, a hoʻoheheʻe ʻia nā mea paʻa.
He haʻahaʻa loa ka resistivity o nā magnet NdFeB, SmCo a i ʻole Alnico magnet. Hōʻike ʻia ma ka pākaukau 1. No laila, inā hana kēia mau mea magnet i nā mea electromagnetic, ʻo ka pilina ma waena o ka flux magnetic a me nā mea conductive e hana maʻalahi i nā au eddy.
Papa 1 Ka resistivity o NdFeB magnets, SmCo magnets a Alnico magnets
| Mākēneki | Resistivity(mΩ·knm) |
| Alnico | 0.03-0.04 |
| SmCo | 0.05-0.06 |
| NdFeB | 0.09-0.10 |
Wahi a Lenz's Law, Eddy au i hana ʻia ma NdFeB a me SmCo magnets, alakaʻi i kekahi mau hopena maikaʻi ʻole:
● Pohō ka ikehu: Ma muli o nā au eddy, ua hoʻololi ʻia kahi ʻāpana o ka ikehu magnetic i ka wela, e hōʻemi ana i ka pono o ka mea hana. No ka laʻana, ʻo ka poho hao a me ke keleawe ma muli o ka eddy current ke kumu nui o ka pono o nā kaʻa. I ka pōʻaiapili o ka ho'ēmi kalapona, hoʻomaikaʻi i ka pono o nā kaʻa he mea nui loa.
● Heat Generation and Demagnetization: Loaʻa i nā mākēneki NdFeB a me SmCo ko lākou wela hana kiʻekiʻe loa, ʻo ia kahi ʻāpana koʻikoʻi o nā magnet mau loa. ʻO ka wela i hana ʻia e ka eddy current loss ka mea e piʻi ai ka mahana o nā magnet. Ke ʻoi aku ka nui o ka wela o ka hana, hiki ke demagnetization, e alakaʻi i ka emi ʻana o ka hana o ka hāmeʻa a i ʻole nā pilikia hana koʻikoʻi.
ʻOi loa ma hope o ka hoʻomohala ʻana o nā kaʻa kaʻa kiʻekiʻe, e like me nā kaʻa kaʻa magnetic a me nā kaʻa ea ea, ua ʻoi aku ka nui o ka pilikia demagnetization o nā rotors. Hōʻike ka helu 1 i ka rotor o kahi motika lawe ea me ka wikiwiki o30,000RPM. Ua piʻi aʻe ka mahana ma kahi o500°C, ka hopena i ka demagnetization o nā magnet.
Fig1. ʻO a a me c ke kiʻikuhi maʻamau a me ka puʻunaue o ka rotor maʻamau.
ʻO b a me d ke kiʻi kiʻi mākaʻikaʻi a me ka māhele ʻana o ka rotor demagnetized, kēlā me kēia.
Eia kekahi, he haʻahaʻa haʻahaʻa Curie nā mākēne NdFeB (~ 320 ° C), kahi e hoʻohaʻahaʻa ai lākou. ʻO nā mahana curie o SmCo magnets, aia ma waena o 750-820°C. ʻOi aku ka maʻalahi o ka loaʻa ʻana o NdFeB e ka eddy current ma mua o SmCo.
Nā ʻenehana Anti-Eddy o kēia manawa
Ua hoʻomohala ʻia kekahi mau ʻano hana e hōʻemi ai i nā au eddy ma NdFeB a me SmCo magnets. ʻO kēia ʻano hana mua e hoʻololi i ka haku mele a me ke ʻano o nā magnet e hoʻonui ai i ka resistivity. ʻO ke ala ʻelua e hoʻohana mau ʻia i ka ʻenekinia e hoʻopau i ke kūkulu ʻana i nā puka lou eddy nui.
1.E hoʻonui i ka resistivity o nā magnet
Ua hoʻohui ʻia ʻo Gabay et.al CaF2, B2O3 i nā SmCo magnets e hoʻomaikaʻi i ka resistivity, i hoʻonui ʻia mai 130 μΩ cm a 640 μΩ cm. Eia naʻe, ua emi nui ka (BH) max a me Br.
2. Lamination of Magnets
ʻO ka laminating i nā magnet, ʻo ia ke ala ʻoi loa i ka ʻenekinia.
Ua ʻoki ʻia nā magnet i loko o nā ʻāpana lahilahi a laila hoʻopili pū ʻia. ʻO ka pilina ma waena o nā ʻāpana ʻelua o nā magnet he insulating glue. Hoʻopilikia ʻia ke ala uila no nā au eddy. Hoʻohana nui ʻia kēia ʻenehana i nā motika kiʻekiʻe a me nā mea hana. Ua hoʻomohala ʻia ka "Magnet Power" i nā ʻenehana he nui e hoʻomaikaʻi i ka resistivity o nā magnet. https://www.magnetpower-tech.com/high-electrical-impedance-eddy-current-series-product/
ʻO ka palena koʻikoʻi mua ka resistivity. ʻO ka resistivity o laminated NdFeB a me SmCo magnet i hana ʻia e "Magnet Power" ʻoi aku ka kiʻekiʻe ma mua o 2 MΩ·cm. Hiki i kēia mau magnet ke keʻakeʻa nui i ka hoʻoili ʻana o kēia manawa i loko o ka magnet a laila hoʻopaʻa i ka hana wela.
ʻO ka ʻāpana ʻelua ka mānoanoa o ke kāpili ma waena o nā ʻāpana magnet. Inā ʻoi aku ka kiʻekiʻe o ka mānoanoa o ka papa kelu, e hoʻemi ʻia ka leo o ka magnet, e hopena i ka emi ʻana o ka flux magnetic holoʻokoʻa. Hiki i ka "Magnet Power" ke hana i nā magnet laminated me ka mānoanoa o ka ʻāpana glue o 0.05mm.
3. Ka uhi ʻana me nā mea kiʻekiʻe-Resistivity
Hoʻohana mau ʻia nā uhi insulating ma ka ʻili o nā magnet e hoʻonui i ka resistivity o nā magnet. Ke hana nei kēia mau uhi i mea pale, e hoʻemi i ke kahe o nā au eddy ma ka ʻili o ka magnet. E like me ka epoxy a i ʻole parylene, hoʻohana mau ʻia nā uhi seramika.
Nā Pōmaikaʻi o Anti-Eddy Current Technology
Pono ka ʻenehana anti-eddy o kēia manawa i nā noi he nui me NdFeB a me SmCo magnets. me:
● High-speed motors: I loko o nā kaʻa kaʻa kiʻekiʻe, ʻo ia hoʻi ka wikiwiki ma waena o 30,000-200,000RPM, e kāohi i ka eddy a me ka hoʻohaʻahaʻa i ka wela ke koi nui. Hōʻike ka Kiʻi 3 i ka mahana hoʻohālikelike o ka SmCo maʻamau a me ka anti-eddy SmCo o kēia manawa ma 2600Hz. Ke piʻi ka mahana o nā mākēneki SmCo maʻamau (hema ʻulaʻula) ma mua o 300 ℃, ʻaʻole ʻoi aku ka mahana o nā mākēneki SmCo anti-eddy o kēia manawa (akau bule hoʻokahi) ma mua o 150 ℃.
●Nā Mīkini MRI: He mea koʻikoʻi ka hōʻemi ʻana i nā au eddy i MRI no ka mālama ʻana i ka paʻa o nā ʻōnaehana.
He mea koʻikoʻi ka ʻenehana anti-eddy i kēia manawa no ka hoʻomaikaʻi ʻana i ka hana o NdFeB a me SmCo magnet ma nā noi he nui. Ma ka hoʻohana ʻana i nā ʻenehana lamination, segmentation, a me ka uhi ʻana, hiki ke hoʻemi nui ʻia nā au eddy i ka "Magnet Power". Hiki ke hoʻohana ʻia nā mea mana anti-eddy NdFeB a me SmCo i nā ʻōnaehana electromagnetic hou.
Ka manawa hoʻouna: Sep-23-2024
