NGHIEN c t r u GIAM DAO DQNG CHO T R y C MAY SLT D U N G B O G I A M D A O DQNG RESEARH TO REDUCE VIBRATION FOR SHAFT OF MACHINES USING THE REDUCED VIBRATION Khong Doan Dien'- Vu Xuan Trirong', Tran Thi Oanh^ Truong Dgi hoc Str pham Ky thudt Hung Yen Hot Ca hoc Ha Npi Truong Trung cdp Nong nghiep & PTNT Hdi Duong Tom tat: Bdi bdo nghien ahi gidm dao dong cho true mdy sir dung bq gidm dao dpng Bdng viec ihiil lap phuong trinh dao dgn g cua true mdy hai trudng hop chua lap va co idp bo hdp thu dao dpng de thdy ro dupc tdc dung ciia bp gidm dao dong viec gidm vd tdt dao dpng cua true mdy nhdm han che dnh hirong ciia dao dpng khong mong muon den khd ndng ldm viec ciia true mdy Tir dp dung thudt todn Runge — Kutta — Nystrom de xdc dinh cdc thong so toi uu cua bp gidm dao dpng voi tieu chi thoi gian tdt dao dpng la nho nhdt Ket qud nghien cmi co the dp dung gidm dao dong cho true mdy ciia cdc mdy co nhdm ndng cao tuoi thp ldm viec cua true mdy THr khoa: Dao dong, Bp gidm dao dpng Thong so toi iru Runge — Kutta — Nystrom l.Dat van de Dira tren ca so Iy thuyet ve bp giam dao dpng ap dung vao viec tinh toan cho true may vai dao dpng cua true la dao dpng tuan hoan Tren ca sa tim cac quan he giira cac thong so ciia bo giam dao dpng va sir tat dan cua dao dong khong mong muon, hoan thien them mpt buac vao cac nghien ciru ciia cac tac gia truoc [5], [6], [7] Tir do, giiip cho viec chpn cac phuang an giam dao dpng theo thiet ke 2.Cv so* ly thuyet tinh toan 2.1.S& bac ty cua ev hf D6 ti'nh so bac tu cua he, ta co the sir dung phuong phap thuc hanh diing so phep "giir": Sdphep "gia " de cho co he cdn bdng dung bdng so bdctudo ciia co hi [2], [3], [4] Hoac su dung cong thirc tinh so b^c tir cua ca he [9]: f=3(p-nj)+'2,fj, 0) Trong d o : / la s6 bac tir ciia co he phang, nj la s6 lugng cac khap dong ca he va_/)^ la bac tir ciia khap dong thu / 2.2 Phuvng trinh Lagrange Ioai II Phuang trinh Lagrange loai II (dang giai tieh ho^c ma tran) thucmg duac su dung de thiet lap he phuang trinh vi phan chuyen dpng cua ca he bat ky voi viec sii dung cac tpa suy rong dpc lap vira dii [2], [3], [4] Dang giai tich cua phuang trinh Lagrange loai II nhu sau: dtXdqJ dq *-(?,; = 1-/ (2) Trong do: / so bac tu eua ca he; T: Dong nang cua ca he; q Tpa dp suy rpng thir /; g,: Toe suy rong thu /; Q, • Luc suy rpng eiia cae lue co the ung vai toa dp thii /; Q, : Luc suy rgng ciia cac luc khong co the ling vai tga dp thir /; Ddi tugng va phinnig phap nghien cmi Doi tuong nghien ctru: True may co khoi lugng M, ban kinh R dao dong theo quy luat (p it) — a s i n ((Jit); tren mot day cung each tam O ciia true may mpt khoang e nguoi ta co lap mpt bp giam dao dong gom mgt khoi lugng m co khoi tam la C va mgt giam chan nhat co he so can la b (ty le bac nhat vdi van toe khoi tam C ctia khoi lugng m) va mgt id xo eo cung c Phuong phap nghien cim: Sir dung phuang trinh Lagrange loai II (dang giai tich hoac ma tran) de thiet lap he phuang trinh vi phan chuyen dgng ciia CO he mo ta dao dgng ciia he, tir vai eac so lieu thuc nghiem ciia true may va thuat toan Runge-Kutta-Nystrom de xac dinh eac thong so toi im cua bg giam dao dpng Cac ket qua 4.1 Thiet lap hf pbutrag trinh vi phSn chuyin ddng cua ctr he - Tlnh so bgc lir cua co he theo (!): So khau dpng p ^ 2, so khap dgng «, = (trong co mpt khop quay va mgt khop trugt) Khap quay co 01 bac tu do, khap trupt phang co Khoa hoc & Cong nghe - S6 02/2014 Hinh Sodo phdn tich van toe Hinh Mo hinh dong luc hpc Dong ndng ciia co he 01 bac tu Do do, ta CO' raj ') (9) f=3(p-nj)+Xf, = ( - ) + (l + l ) - - Chgn tga dg suy rpng dgc lap viia du la djeh chuyen tuong doi s cua khoi lupng m so voi ranh trugt cua true mdy vd goc quay