Mòn cổ góp chổi than của động cơ điện một chiều trong điều kiện khí hậu nhiệt đới ẩm

NGHIEN ClJU - TRAO OOl M O N CO COP - CHOI T H A N CUA f)QNC C d f>IEN M p T CHIEU TRONC P I E U K I E N KHI H A U N H I E T f>dl A M Pham Van Hung, LI DiJfc Bdo BO mdn May vd Ma sdt hpc Trddng Dgii hpc Bdch khoa Hd N^i T6M TAT Dong cd dien mdt chiSu cd co gdp chSi than dUdc dungphS biln cdc thilt bi cdng nghi^ yeu cdu cd mdmen khdi ddng vd khd ndng qud tdi cao, ddc biit, cdc thilt bj cdng nghi cao nhUmdy CNC vd cdc he thdng cd dien td Trong qud trinh Idm viec, ddng cd dien mot chieu thUdng bj huhdngco gdp vd choi than, nhdt la dieu kien cd dm cao Bdi bdo ndy trinh bdy thilt bj thi nghiem vd ket qud thuc nghiem ve dnh hUdng cua hau nhiet ddi dm vdi hai thdng so chinh Id nhiet do, dm den ma sdt, mdn co gdp choi than ddng cd dien mot chieu Qud trinh thUc nghiem dUdc tiln hanh vdi cdc thdng sd ddc trUng nhU cUdng ddng dien vd toe quay cua Roto, dieu kien nhiet dd vd dm thay doi Kit qud thUc nghiem bUdc ddu dd cho thdy thj mdn cua co gdp vd choi than phu thudcvdo ddc trUng nhiet dm Viet Nam ABSTRAST Wear of commutator- brush DC motor in the tropical conditions of humidity DC motor with commutator - brushes are used in industrial equipment by a high starting torque and overload capabiU^ Especially in the high-tech equipment such as CNC machines and mechatronic systems, the DC motor is used very common During the work, the DC motor is often damaged commutator and brush, especimj in high humidity conditions This paper presents experimental equipment and experimental results on the effects of humid tropical climate with two main parameters as temperature, humidity onto frictional wear of the commutator pairs - brush DC motors Experiment was conducted with parameters specific to ike ability of DC motors such as electric current intensity and speed of the rotor Initial experimental results showed worn graphs of the commutator and brushes depends on the parameters of direct current, rotor speed and temperature- humidity characteristics Keyword: wear, commuter and brushes, DC electric motor, tropical climate, tribology in DC motW- TAP CHI CO KHI VlfiT NAM ••• Sd 1+2 (Thdng 1+2 nam 2012) NGHIEN ClJfU - TRAO D | DAT VAN DE Trong cdc loai ddng cP dien dung may cdng cu, dpng cP dien mdt chilu ddpc sd dung d nhdng noi yeu cau mdmen md mdy Idn hoac yeu cau dilu chinh tdc dp bang phang va pham vi rpng Trong cdng nghiep, cdc thiet bi tii ddng, cdc dpng cP chap hanh, cdc thilt bi d td, tau thuy, mdy bay, thilt bi dien hod, thilt bi hdn dien cd chat Idpng cao dIu sd dung ddng cP dien mdt chilu Ddng cP dien mdt chilu 1dm viec dUa tren nguyen ly cam dng dien td Ddng di?n mdt chieu diipc diia vdo phan dng nhd cum chdi than cd gdp Co cau choi than dl diia ddng dien td ngodi vdo phan quay Roto Co cau choi than gdm cd choi than ddpc dat hop choi than vd nhd mdt Id so ty chat len co gdp Co gdp choi than cd nhiem vu diia dien vdo hoac lay dien day quan roto cua mdy dien thdng qua tilp xdc triipt gida choi than vd bl mat co gdp Trong dilu kiln lam viec khde nhii nhiet dp cao [3], dp am cao [5], bui ban thi van dl ma sdt, mdn cua choi than CO gdp dnh hiidng khdng nhd din boat ddng cua ddng cO dien mdt chilu Viec bao diidng kilm tra tinh trang co gdp, mdn choi than vd kha ndng thay thi, cdc bilu hien tren bl mat co gdp la quan trpng vd can thilt [4] Choi than diipc chia 1dm loai chinh Carbon Graphit, Graphit, Graphit dien luyen (Choi than Graphit nhdn tao) vd Graphit kim loai Moi nhd sdn xuat cd mdt cdng thdc rieng vd cdch ddnh sd rieng cho tdng loai vat Ulu chiiong trinh sdn xuat cua hp Chung ddpc ddc triing bdi cac gid tri dien trd suat, mat dp ddng dien cho phep, tdc dp ddi cho phep trIn vdnh gdp, he sd ma sdt, dp cdng choi than Co gdp dien Id mdt nhdng cum chi tilt phdc tap nhat cua mdy dien mdt chilu Khi lam viec, co gdp chiu tdc ddng rat Idn cua liic ly tdm, nhiet dp cao (cd thi len den 1000°C) phdt sinh td ldc ma sdt cua choi than len vdnh gdp vd td tia Ida tilp xdc cua choi than khdng on dinh, ddng ddo chilu vd dp lech diidng trung tinh hinh hpc cua cum choi than, Neu cdng nghe chi tao khdng tot cd the xdy cdc tinh trang 1dm viec khdng tot nhd sau: bl mat co gdp cd hmh tru trdn dIu nhdng true co gdp lech so vdi true roto nen quay tao dp nhay cua be mat co gdp; be mat co gdp bi meo cd sii dich chuyin theo hddng kinh cdc philn gdp Sii biln dang cua co gdp co thi la tinh (meo san), hoac biln dang ddn hdi (meo lam viec) Nhii vay cd the coi choi than co gdp nhii tim cua dpng ca dien mpt chieu va la dilm ylu nhat cua he thdng VI ban chat nghien cdu vl choi than co gdp ddng ca dien thdc chat la nghien cdu vl dac trUng tribology cua cap vat lieu cdcbon- ddng hoac graphit - ddng Do do, bdi bdo ndy diia kit qua nghien cdu mdn co gop choi than phu thupc vdo bp thdng sd: cddng dp ddng dien, tdc dp quay Rdto vd dac triing nhiet am Id nhiet dp, dp am Kit qud nghiln cdu cd thi 1dm ca sd cho viec xdc dinh thdi gian lam viec dn dinh vd dii tru thay thi, sd chda ddng ca dien mdt chilu Ddc biet dieu kiln 1dm viec cd dp am cao d Viet Nam PHl/ONG P H A P NGHIEN CCU 2.1 Phddng phap nghien cdu Tilp xdc gida co gdp (Ddng) choi than (carbon) thddng cd he sd ma sdt cao De giam he sd ma sdt tren co gdp diipc phu mdt Idp mang mdng [7] (Idp mdng cd mau xin, tdi, khdng Id Idp ddng sau liing) Choi than hi mdi mdn cO hpc tilp xdc ma sdt tai bl mat lam viec diidi tdc ddng cua ddng dien di qua bl mat tilp xdc Mdn co hpc xdy ma sdt tai bl mat tilp xdc 1dm cho cdc phan td mdn hi tdch khdi bl mat choi than, tao cdc bui Carbon Nlu dac tinh cua choi than hpp ly, he sd ma sdt gida choi than vd co gdp se nhd nhat, qud trinh lam viec se xuat hien mdt Idp vat lieu thd nam gida hai bl mat choi than vd co gdp, gpi la Idp mdng mdng cd chilu ddy cd vdi chuc A" cdn gpi la vat the thd ma sat, nd bao gdm cdc vi tinh thi graphit, hoi niidc vd dxyt kim loai Ldp mdng ndy diipc tao tdc dung dien hda cua ddng dien, graphit cua choi than, hoi am khdng va kim loai cua be mat tiep xuc Mdn dien xdy ddng dien di qua be mat cd dien trd cao tilp xuc dien khdng tot, gdy sd phdng ho quang lam giam Idpng Carbon tilp xuc Qua trinh mdn ddpc gid d trang thdi nhd nhat bang cdch tao "^ TAP CHf CO KHI VIET NAM •!• Sd +2 (Thdng +2 nam 2012) NGHIEN COfU - TRAO OOl be mat cd tilp xuc di?n la tot nhat Trong dieu kien lam viec thdc tl mdn cua cap choi than CO gdp chiu dnh hddng cua nhieu thdng sd nhd nhiet dp, dp iim, ddc tinh tdi, van ldc, liic nen Id xo, ddng dien Trong dieu ki?n nghien cdu phdng thi nghiem, cap v^t lieu ndy ddpc nghien cdu vdi cdc thdng sd dnh hudng chinh id cddng dp ddng dien, tdc dp quay cua Roto, nhi?t vd dp am, nham xdc dinh dnh hddng cua dp am den mdn cap co gdp chdi than theo khdi Idpng, td dd xdc dinh cuong dp mon cua cap vdt lieu co gdp chdi than 2.2 Mdu c6 gdp mdn ch6i than thd nghiem Vi?c Ida chpn mdu cd gdp - choi than thu nghiem phdi phu hpp thdc te su dung tai Vi^t Nam, dam bao tieu chuan j^'it lupng Mau choi than ddpc Ida chpn Id mdu th|)ng dung thj triidng Vi|t Nam, thudng ddpc ding de thay the Mdn cua cd gdp chdi than thi cho chdi than ddng cP dien nnot chieu Mau nghiem ddpc xac dinh theo khdi Idpng mat di cua cd ky hieu 417A, cua hdng Makita Trung Quoc, chdi than sau thdi gian thd nghiem so vdi mau kich thiidc va binh ddng ddpc thi In en tren hinh ban dau Cap chdi than cd gdp boat dpng Mau CO gdp thd nghiem cd the dung toi da 1= dilu kiln thay ddi, cac thdng sd ciidng dp ddng lOA, Van tdc quay tdi da nmax = 3000 vong/ dien, tdc dp cda Roto vd thdng sd mdi trddng Id phut, dp ldc Id xo Pmax = 0.2 kG dupe the hienci nhiet dp, dp am Liipng mdn U(g) dxicic xdc dinh hinh ^ 13 Hinh 1: Hinh dang va kich thUdc choi than 417A Hinh 2: Hinh dang va kich thUdc c6 gop 32 lan l l TAP CHI CO KHI VlfiT NAM • Sd 1+2 (Thdng 1+2 nam 2012) NGHIEN ClJfU - TRAO DOI 2.3 Thiet bi thd nghiem mdn choi than co gdp dieu kiln nhiet do, am thay ddi Dl tiln bdnh thd nghiem mdn cap ma sat co gdp - choi than dieu kien nhiet dp va dp am thay doi vdi cdc ddc trdng cda hau nhiet ddi am Viet Nam, can cd thiet bj thd nghiem mdn va thiet hi tao mdi trddng nhiet am j ^ J- < J* < nhiet dp va dp am co diipc thi cilPng dp mon cua choi than I phu thupc vdo nhiet dp T'C vd dp am tuong doi RH% tai I=5A dapc the hien tren ^-^ u o T^ A' U-* j - ^ /Ti,/-N A"" hinh 4.2 Trong x nhiet dp ( P C ) , y - dp am tifpng doi (RH%) Hdm hoi quy thiic nghiem thu dPpc Id phiiPng trinh ciidng dp mon cua choi than I,^.^ phu thupc vdo nhiet dp vd dp am tUPng doi la I=-1.3699+0.0341x+0.0301y-0.0004x'+0.0005xy0.0002y^ ^,., , ,, , Tai heu tham khao: ^ A u T " nr^c TC DV, [IJ.VS.GS TSKH Nguyen Anh Tuan, POSTS Pham Van Hung, Ma sat hpc, NXB Khoa hpc vd Ky thuat, 2007 [2] PGS.TS Nguyen Doan Y, Xxi ly so lieu thiic nghiem ky thuat, NXB Khoa hoc va Ky thuat Ha Noi, 2004 [3] Janko Slavi, Miha Bolte; Measuring the dynamic KET LUAN Viec nghien ciiu anh hUdng cua nhiet am forces to identify the friction of a graphite-copper contact for variable temperature and current; Wear den mon cua choi than co gop bang thiet bi tao nhiet am BKNA 2010 vd thiet bi tao mon BK.MCT 2010 da cho thay khd nang linh hoat va tin cay cua 260 (2006) pl 136-1144 thiet bi diipc che tao ratus for measure-ment of the dynamic coefficient of r< > U ** X u-A-^ "^ *x^„ ^.-^^ AA O cung nhiet dp, dp am tang cung dp mon tang dieu ndy khang dinh dnh hifdng ro ret cua am tiiPng doi den mon Khi am tang co hi, J ^ J 1.' J - !-> J A'T" :kha nang mon phong dien tang len do tong mon CO hpc vdphong dien tdng Gid tri Idn nhat cua ciidng dp mon khong thii nguyen d nhiet 55°C vd dp am tiiOng doi 99% khang dinh mdn ch6i than cd nguy ca cao bat dau chuyen sang dan tiep xiic ddn deo „v^ , , ,^ u ^-u'"- ,;A^ ^x^ Ket qua nghien ciiu cho thay, viec xac dinh lupng mdn bang khoi liipng, roi tinh cifdng / p mdn I, Id phu hpp Ket qud tinh todn cho thay cifdng dp mdn Id 10"^ nam vung dan hoi va fcndn Id binh thif dng K] M Milkovi, Test methods and measuring appa- frictionofbrushes Carbon 30 (1992) 587-592 [5] Robert J Hamilton, Brush life in DC motors, ReliT^, ^ ance Electric [6] E Shobert, Carbon Brushes; the Physics and ch^j^istry of Sliding Contacts, Chemical Publishing Company Inc., New York, NY, 1965 [7] Pradeep L Menezesa, Kishorea, Satish V Kailasb, "Studies on friction and transfer layer using inclined scratch"; Tribology International 39 (2006) 175 - 183 ^^^ ^ ^ ^aidi, D Paulmier, Friction behav- ^^m of a graphite-graphite dynamic electric contact in the presence of argon, Wear 192 (1-2) (1999) 151-156 Can ciJ vdo IdPng mdn [U] cua choi than va c6 gdp cd thi xdc dinh diiPc tu6i thp vdi tin [9] • R-C Hilbbeler ; Engineering Mechanics; Prentice cay phu hpp thdng qua toe dp mdn y = v.I Nen ^^11,2004 (Statics and Dynamics) iKu y [U] diiPc xdc dinh theo dieu kien 1dm viec ^ ^ ^ ^ ^^^.„ „ ^ u i ^ uv u A ,,v V •, X , \ • w-^u ^A„A« 10 J A Williams; Engineering Tribology; Published l^d ket cau cu the cua tifng loai choi than - CO gop ^ J ^ I in United State by Oxford Univrsity; Press Inc NewYork 1996 TAP CHl CO KHI VIET NAM ••• S6 1+2 (Thdng 1+2 nam 2012) ... chdi than cd gdp Co cau choi than dl diia ddng dien td ngodi vdo phan quay Roto Co cau choi than gdm cd choi than ddpc dat hop choi than vd nhd mdt Id so ty chat len co gdp Co gdp choi than cd... choi than, tao cdc bui Carbon Nlu dac tinh cua choi than hpp ly, he sd ma sdt gida choi than vd co gdp se nhd nhat, qud trinh lam viec se xuat hien mdt Idp vat lieu thd nam gida hai bl mat choi than. .. mdn cap co gdp chdi than theo khdi Idpng, td dd xdc dinh cuong dp mon cua cap vdt lieu co gdp chdi than 2.2 Mdu c6 gdp mdn ch6i than thd nghiem Vi?c Ida chpn mdu cd gdp - choi than thu nghiem phdi