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Cong tnnh Khoa hpc SU BlfiN DANG CUA G I DOf DANG BAC LOT DU^Ol TAC DUNG CUA AP S U A T T R O N G MANG DAU BOI TRON NGUYEN THIET L ^ P Khoa Cakhi Trir&ng Dgi hgc Giao thong Van tai Tdm tat: Bdi bdo trinh bdy su bien dgng cua gdi dd dgng bgc Idt dirdi tdc dung cua dp sudl Irong mdng ddu bdi tran Ap sudt mdng ddu dugc xdc dinh thong qua viec gidi gdn dung phuang trinh Reynolds bdng phuang phdp Newion - Gaphson vd phucmg phdp Igp Gauss - Seildel Bien dgng cua bgc lot vd gdi da dugc xdc dinh bdng cdch dua dp sudl mdng ddu vdo mo hinh Abaqus Summary: The paper presents the deformation of the shells and the housing of journal bearings under the pressure in the oil film for lubrication The pressure in the oil film is defined by par resolution of the Reynolds equation with the Newion - Gaphson method and the roop of Gauss - Seildel method The deformation of the pads and the housing are calculated by transfering the oil film pressure into the model of Abaqus I D A T V A N D E Su bien dang c u a cac gdi d d se dnh h u d n g d i n k h a nang l a m vi6c, kha n a n g bdi tiem ciing n h u tudi thg cua gdi T r u d c ddy, nghien ciiu cac gdi d d dang bgc tren ddng c a ddt tiong (c6 khu^oi, cd bi6n, chdt pit tdng), n g u d i t a t h u d n g coi gdi d d khdng bi b i i n dgng Trong hai thap ky gdn ddy, d a cd nhiing nghien ciiu v l s u b i i n dgng ciia gdi d d tiong qua tiinh lam vi$c Nhiing nghien ciiu n a y coi s u bien dang va s u trugt sinh m d t l u c tap t n m g quay vdng dgt vao gdi d d [1] - [3] T h u c t e , tai tigng tii cd true tac d u n g len b e m a t gdi d d d u g c phdn b d mang dau bdi tion Cac nghien ciiu v l bdi Iron thuy dgng da chi rang, a p suat mang ddu boi tion cac cd true, cd bien d u g c phdn b d dang parabol theo chieu rgng ciia gdi d d va khdng doi xiing theo chu vi cua gdi [4] - [8] G i a tii cda dp sudt phdn bd n a y p h u thudc n h i l u y l u Id khac nhau: thdng sd k i t cdu, nhiSt do, tai tigng lac dung 16n gdi d d va su khdng lien tuc ciia mang dau, Dudi tac d u n g ciia ap sudt m a n g dau, gdi d d bi b i i n dgng khdng d i u theo chilu rdng va 18ch khdi p h u a n g ciia lire m d t khoang nhdt dinh Trong m g t nghien ciiu gdn day, de ddnh gia d o m d n cua gdi d d cd bdi tion thuy ddng, Dutfoy L va Ligier J.-L [9] d a m d phdng su bi8n dgng gay r a d o ap suat mang ddu, n h u n g chi danh gia tgi mgt vi i n cda luc tac dimg vao c6 bien (phia than truyln) Nghien ciiu n a y se k i t h g p giua viec tinh toan ap sudt mang ddu tien c o s d p h u a n g tiinh Reynolds va viec tinh toan bien dgng cua gdi d d bdng p h u a n g phdp phan tii hiiu h a n (FEM) Q u a dd cd the xac dinh chinh xdc viing bien dang cung n h u danh gia miic d o bien dgng ciia gdi d d vdi c h i bdi Iron thuy dgng 128 Tap chi KHOA HQC GIAO THONG VAN TAI S6 dac biet - 11/2015 Cdng trinh Khoa hpc n AP SUAT TRONG MANG DAU BOI TRON Xet gdi dd dugc bdi tian bdng mgt mang dau mdng cd chieu day rat nhd so vdi cac kich thudc cua gdi dd, cd thi bd qua quan tinh ciia diu Gia thiet ddng chay ben la ddng chay tdng, lien tuc va ddu khdng chiu nen Liic dd, phuang trinh Reynolds cd the vilt dudi dang don gian nhu sau: dx[6\idx.J 5zl^6p5zj ax dt ^ -' Trong dd: p la dp suat Ihiiy ddng; h la chilu day mang ddu; U la van Idc tuang ddi theo phuang tiep tuyen ciia gdi dd so vdi tryc; t la thdi gian; \i la nhdt ddng luc hgc ciia ddu Tgi cdc vi tri mang dau gian dogn hodc hai ben canh cua gdi dd tiep xiic vdi khdng khi, ap suat khdng thay ddi nen dao ham se bdng khdng Do dd, phuong trinh (1) cd the vilt thanh: dip h) dip h) ax a Vdi p„ la khdi lugng rieng cua dau cd lln Khi tinh todn ap suat phan bd mang dau, chiing ta se phai xdc dinh ddng thdi ca viing lien tuc va vung gian doan Do dd, bdng each su dung mdt bien loan ndng D ta cd thi gdp hai phuang trinh (1) va (2) mgt [7] FAfill^VpArili5Lu^,2*.(l-F)rU^.2®l axl^dpaxj azl^6pazj ax at ^ ax at j (3) ^' Vdi F la he sd phu thudc cac vung bdi Iran Trong viing cd mang dau lien tuc thi ap suat can bang vdi ngoai Igc tac dung,ta cd : rD=p-p^ F-1 ^ ^ Vdi p^ la dp suat vung gian doan Ap suat khdng ldn hon dp sudl tiong mdng ddu p (p>p„)nenD>0 Trong vimg mang dau gian doan, theo dinh luat bao loan khdi lugng ta cd: (5) Do p^ khdng Idn hon p nen D < Bk xdc dinh chilu day mang ddu d vi tii M( 6, z) tai thdi dilm tciia gdi dd co ban kinh true la R^ va ban kinh Id la R^ (hinh 1), la coi nd dugc hinh tii hai phan: khe hd kich thudc cua true va Id h|j{9,z,t); va khe hd bien dang dan hdi cua chi tiet h^{6,z,l) Nhu vay, chieu ddy mang dau cd the bilu diln nhu sau: h(e,z,t) = ho(e,z,t) + h,(0,z,t) Tap chi KHOA H Q C GIAO THONG VAN TAI S6 d a c biet - 1 / (6) 129 Cdng trinh Khoa hpc Hinh Mat cdt ngang goi dd D8 xdc djnh hg (6,z,t), ta coi gdi dd diing yen va true quay Thdng Ihudng, khe hd giua true va gdi dd rat nhd nen dich chuyen ciia tam true la khdng dang ke so vdi ban kinh ciia nd Do dd, phuong trinh can bdng luc tdc dung len true chilu len hai phuang x, y (hinh 1) cd the vilt thanh: JJp.cosG ds-F, -s (7) JJp.sinO ds-F^ : Trong dd, F, va F^, la ngoai lire tac dung len true chieu len hai phuang x, y De xdy d\mg bieu thuc tinh loan ap suat mang dau gdi dd cd be rdng la B, chu vi la L, ta cdn khai tiiSn gdi theo phuong x, z Luc dd, b6 m§t gdi dd khai trien cd chieu rdng theo z la B, chilu ddi Iheo x la L, khe hd theo chilu y la h Chia dogn (0, L) n phdn bdng va doan (0, B) m phdn bdng Su dung phucmg phap gdn diing Newion - Gaphson dl tinh dgo ham rieng lai mdt diem bat ky Mi (x, ;h,j; Zj), ta cd cac h? phuang trinh sau:
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