CIAI PHAP SO KHAO SAT BIEU t>6 AP SUAT 6 THUY PQNC

NGHIEN cflu - TRAO D 6 I

CIAI PHAP SO KHAO SAT BIEU t>6 AP SUAT 6 THUY PQNC

Digital solution for studying on hydraulic pressure of journal bearing

Trfn Van Thilc, PGS.TS. P h a m V i n Hiing

Bo mon Mdy & Ma sdt hoc, Vi|n Co khi, Tru6ng D^i hoc Bach khoa H i Nfii

T O M TAT

Hien nay, bdi trdn thiiy dgng dUdc sd diing khd pho bien trong cdc thiet bi mdy mdc. Cdc 6 titHy dgng thudng dung trong cdc kit cdu cd tdc do quay vd tdi trong ldn. Vtec khdo sdt dp sudt thdy dgngtai vung chiu tdi trgng cita 6 bdi trdn Udt cdy nghia quan trgng trong viic xdc dinh khd ndng tdi cita o, tddo, CO the dUa ra cdc cdi tiin kit cdu hdp ly cho khd ndng tdt cao hdn. Thiet bi do dp sudt 6 thiiy ddng truyht thong chu yeu sd dting cdc ddu do cd cd nhieu hqn chi vi tdn sd ldy mdu, sai so do tri ldn ddn den ddp itni chdm hoac dung cdc ong bo tri xung quanh chu vi 6. Trong bdi bdo ndy tdc gid dd dUa ra gidi phdp do tip sudt 6 thuy ddng sddiing ddu do so. Thiet bi khdo sdt dp sudt 6 thity ddngsd diing ddu do sd cho phip do liin tttc dp sudt ddu trin chu vi 6 vd ddu do dUdc kit not mdy tinh. Tin hiiu dp sudt trin o thuy ddngqm ddu do dugc chuyen doi thdnh tin hiiu sdvd mgt phdn mem mdy vi tinh cd nhiim vti xdy dting do thiap sudt 0 thuy dgng trin chuvi 6. Gidi phdp so cho phep khdo sdt biin do dp sudt 6 thuy dgng chinh xdc, tilt cdy vd hiiu qud rdt phu hdp vdl cdc phong thi nghiim chuyin ngdnh bdi trdn.

ABSTRACT

Now aday, hydraulic bearing lubrication is commonly used in many industrial equipments. Tk hydraulic bearing is often used in high speed and heavy load mechanisms. Studying on hydraulicpressuri at loading area of wet lubrication bearing play an important role tn determining the load capacity l^

the bearing and then propose structural Improvements for higher load capacity. Conventional hydradt pressure measuring equipments mainly use mechanical gauges which have limitations in samplinS frequency, errors due to slow response or sampling tubes arranged around the brush of the bearing. In M paper propose a solution for measuring hydraulic pressure of journal bearing using only one digital sensot This measuring equipment continuously rotates around the brush of bearing and measring result is setil to computer. Pressure signals are proceed by a computer software then plot hydraulic pressure profile ofiti bearing. The digital solution allows to study profile of hydraulic pressure accurately, reliablely, and effecHdj It is absolutely appropriate with lubrication laboratories in Vietnam.

TAP CHI C O KHl VlfiT NAM • So 5 (Thang 5 nam 7(117^

1. G I 6 I THifiU

O thuy ddng vdi n h i l u flu diem: kit cau gpn nhe, re, yeu eau bao tri it, tudi thp kep ddi va hieu qua bdi trOn tdt n i n nd dflpc sfl dpng rdng rdi cho n h i l u flng dung khdc nhau cua c h l tao mdy co khi. Mat khac, mdng dau eung tao ra kha ndng hdp thu sdc va cho p h i p giam chan vd dupe coi nhfl mdt thdng sd thilt k l de kiem sodt rung ddng. Trong thflc tien h i | n nay, dd xuat h i | n nhilu loai vdt lieu mdi cd tinh chdng mdi mdn vd ma sat rat cao, ddng thdi vdt lieu bdi tron tdng hop cd kha nang bdi trdn cao n i n da xuat hien cde phfldng phdp thiet k l cdng n g h | ddm bdo tudi thp va dp tin edy eua cac cum mdy va ehi tilt mdy trln CO sd ddm bdo mang ddu bdi trOn fldt. d Viet Nam, vile eung cap day dfl cdc thdng tin phuc vu eho tinh todn thiet ke d dd thuy dpng Id rat han chl. Cdc thiet bi hien ed chu ylu sfl dung cae dau do CO vdi ddp flng eham cd nhilu sai sd do hiin tflpng tre dp cua chat Idng hay sai sd cua cdc bd truyin CO khi. Hon nfla, khi sfl dung cac dau do CO gay khd khan khi tfl dpng hda thilt bi. Vdi ylu eau eua vile hien dai hda thiet bi, ndng cao tan sd lay mau va dam bao qud trinh do la liln tuc tren ehu vi d thuy ddng tde gid dd Ifla chpn dau do sd cho ddp flng nhanh, tan sd lay mau ldn vd dp chinh xdc cao. Ddng thdi, tac gid eung viet phan mem mdy tinh d l thu thdp xfl ly kit qud do, tfl ddng dilu khiln qud trinh do vd ve bieu dd dp i s u a t .

2. P H A N Tf C H T H I E T KE H £ THONG 2.1. Kit c l u CO khi

D l ddm bdo qud trinh Idm viec binh

! thfldng cfla d va lay dflpc sd lieu chinh xde thi I cum ehi tilt quan trpng nhat eua kit eau ca khi I do Id cum 6 dd bdi tron thiiy dpng tdi trpng tinh I vdi cdc thdng sd lam viec nhfl sau:

; Tdi trpng tinh ddt vdo F =500 N, ' Tdc dp quay cfla true 1350 vdng/phut, T ^ t = 28"C.

i Vdt li|u lam true bang t h i p 45 tdi vdi cap chinh xac la 8: Rz = 3 pm.

Vat lilu Idm bac bang ddng ed cap ehinh xac Id 8: [P] = 1,5 MPa. Rz = 7 \xm,

H | sd truyin nhiet cfla vat lieu d trong khdng khi: a =1,97 —

Dflng dau bdi tron

- Ddu cdng nghi|p cd dd nhdt dpng Iflc hpc H = 0,015Pas

- Khdi lupng rilng

p = 0,880kg/dm^

Kit cau d vd so dd tinh tren hinh Ivd hinh 2:

Hinh 1: Kit cau d dd boi trOn thuy ddng

Hinh 2: So do tinh toan cua d Vdi cdc dilu kiln dau vdo nhfl t r l n can xde dinh cdc thdng sd hinh hpc va kha nang tdi e u a d [4]:

TAP CHf CO KHf VlfiT NAM • S6 5 (Thdng 5 nam 2012)

NGHIEN cflu - TRAO 0(51

c h o n ti so:

. \ . ^ . U 8 b = 3 6 m m , d = 2 8 m m Kiem tra lai dp suat cho ph^p

P,b--_{bd 36.28} =. 0.579.UPa < IPn) - l,4.Wi><J Xdc dinh klie hd bdn kinh

C=Ri,^-Jl^, = 0,03mm = 30/m Tinh so Somerfield

0.01S.O.03{.O,0S6.13i0f 12 1 0 ' ' 'I

/ilD.v; Si'

11 ; c 500.60 0.03 10"- • OJl Can cil A tra bdng 2.1 [41 ta c6 cdc thong so sau:

Khe h6 tilong doi £ = 0,4 Goc chat tai i? - 62 5"

He so ma sat khong thii nguyen ft, = 5.0"

Liiu luong khong thtt nguyen j3 =0,314 Momen ma sat khong thii nguyen C„=i9,5 Chieu day mang dau nho nhat.

h = C ( l - £ ) = 0,03(1-0,4) =0,018 mm

Liiu lltong dpc troc.

Q= Q .L.C.V= 0,314.36.10' .0,03.10' .5,2

= 1,76.10'(m'/s) 2!l.NJt Trong d6: v

60 5.2(m'j) Tinh hi s6 ma sdt.

^ . 7 £ = 5 . 0 7 . 2 ^ = 0.01

^' •^' R 14 10"' Tinh M6men ma sat.

C,

C,.SC __ 19.5 0,21 0,03-10'- 14.10"'0,01 ^{= 0.87JVm} Xdc d j n h c o n g sutft t o n hao.

2;r V i ' = C < a = C „ i 2 ^ = 106<>r)

60 Xdc dinh do tang nhi?t dO.

^ j . A.P 0^.106 P-Cp.Q 880.2000.0a76.IO '

= 31,5"

Trong do A = 0,85-^0,9 he so hap thy nhiet ta chon i = 0,9

So do dong ctia thiet bi nhii hinh 3.

Dong CO DC Bg truySn dai Bo traySn true vit thang ^ -banh vit

Cam bien ap suit

Hinh 3: So do dong thift bi

TAP C H i C O KHI VlfiT NAiM • S6 5 (Thdng 5 nSm2012]_

Dpng ca dan ddng dam bao ylu cau v l cdng suat, sd vdng quay, ylu cau ve qua tai, md- men md may vd phflong phdp lap dat dpng eO.

Cdng suat ddng co P.^ = 0,7 (Kw); n = vdng/phut

1350

Bd truyin dai thang vdi sd dai z = 1, dfldng kinh banh dai d, = d^ = 80 mm.

O lap true cdng tac dflpc chon Id d lan cd ky hieu 206 theo tilu chuan COST 8338-75 bang P2.7 [5].

De lay dflpc gia tri ap suat cua d thuy ddng theo chu vi d, bac dflpc dan ddng quay tflOng doi xung quanh true nhd bd truyin true vit bdnh vit nhfl hinh 4. Trln chu vi cfla bac dflpc trich mdt dfldng dau de lay tin hilu dp sudt.

2.2. Giai phdp khao sat bieu do ap suat sfl dung dau do so

Trln CO sd phdn tich sa dd ddng cua may de do dflpc tin hieu ap suat thuy dpng va ve dflpc bieu dd ta can phai sfl dung hai cdm biln:

- Cam biln vi tri - cdm biln ndy cd n h i l m vu xdc dinh vi tri cua dau do t r l n chu vi cfla d tfl dd may tinh tinh todn va dilu khien dau do d i n vi tri phu hpp lay tin h i | u dp suat.

- Cdm biln dp suat - dfldi tdc dung cua dp sudt trong 6 lln cdm biln, tin hieu dp suat dflpc ehuyln thdnh tin h i | u d i | n vd truyin vdo mdy tinh.

Cd t h i sfl dung cdc dau do ca de xdc dinh dp suat thuy ddng tai cac vi tri khdc nhau. Tuy nhiin, dp ehinh xde thap, do dpc bang mat va nhdp dfl lieu bang tay cac dau do co nhfl t r l n liinh 6.

Hinh 6: Kt-t can dau do cci

1 r-"-"i T l

1

1 -«naJ

Hinh 5: May thflc te sau idii lap rap

Hinh 7: Kcl (.]ua d o khi su dung dau do .:i( duo'c so hoa Hien nay, trong cac he thdng do Ifldng - dieu kiiien hien dai thUdng sfl dung dau do sd va qua trinh thu thap va xu li tin hieu thudng do may tinh dam nhiciii.

Tliict bi do duoc sfl dung la cam bien ap suat ML100PS2PG. Cam bil'n ap suat ed vd lam bang thep khdng gi, co khulch dai dau ra, cd cac cdng dflpc c h l tao theo tieu chuan chau Au, dai

TAP CHf C O KHi VlfiT NAM •t* Sd 5 (Thang 5 nam 2012)

NGHIEN cflu - TRAO 06l

do tv( 0 psi den 100 psi. Thdi gian ddp ling n h i hOn SOOmicro giay Tdc d(/ do lil6ng nhanh vdi d6 chinh xdc cao, han chS dlioc cdc dnh hiJdng cua moi tril6ng. Vdi cong ngh§ c6 khd ndng bit sai so, thiet bi do s6 cung cap k^t qud do chinh xac va gidi phdp ve tii dong hda cho cdc ling dyng cdng nghiep. Bdng dudi day Id mot vdi thdng s6 cua cdm bien dp suat ML100PS2PG.

Bdng 1: Cac thong s6 CO bdn cua cdm bi^n ML100PS2PG

Gidi do dp suat Ngudn cap Ap suat qua tdi ldn nhat Bu nhi|t dp Kilu ddu ra Thdi gian ddp flng Gidi nhiet dd dflOc bu Trpng Iflpng

0 - 100 psi 9,5 Vdc - 35 Vdc 150 psi ed 4mA - 20mA Nhd hon 500ps - 4 0 ' ' C - 105"C 57g

Vdi vile sfl dung dau do sd cho dp ehinh xdc cao, dap flng nhanh cd the do trln toan bp chu vi d. Tin hilu trd vl la tin hilu dien dflpc bd vi xfl ly tiep nhan va bu trfl cdc sai lech dflpc tinh toan trong trflong trinh dilu khien do do he thdng hoat dpng dn dinh va eho kit qud rat dang tin cay.

Trln hinh 8 Id hinh anh ci'ia mot dau do sdr

Pressure sensor

Miy Tfnh

1 I

ATmcga 16

LCD

' 1

/ D^ngCa i

Hinh 9: So dd cdc khdi dilu khiln .J Cde md dui chinh cfla khdi dilu khiln g&^

- Md dui dilu khiln dpng eO ed phdn hdi vj tri vi tdc dO;

- IVId dui thu nhdn tin h i | u dp sudt tfl 6 thuy d^i^

- Md dui giao tilp vdi may tinh;

- Md dui h i i n thi sfl dung LCD, md dui ndy co n h i l m vu h i i n thi tdc dp ciing nhfl vj tri ciia dpng ca.

Trln hinh 10 trinh bdy cac bo mach dieu khien dpng cO, mach giao tiep vd mach in toan thilt bi.

Mach nyuvt'ii ly dilu khien dpng CO

0 i^jli^cr^

HinhS Daudo.sn

Cac tin hieu nay duoc Iruyen vao mot mach vi xil Iy. Tin hieu ra cua mach nay duoc truyen vao may tinh thong qua phan mem tinh toan xay dung do thi dp suat 6 thiiy dimg, dong thdi dieu khien chinh xdc vi tri ciia dau do tren chu vi 6. Tren hinh 9 la so do cac khiii dieu Ithicn.

Mach giao tilp

Hinh 10: Mach toan thiet bi TAP CHl CO KHi V I £ T NAM • Sd 5 (Thang 5 nSm 2012)

Phan mem dilu khien

Chuong trinh dieu khien dflpc xdy dflng tren ngdn ngfl lap trinh Visual Basic vdi cac md dui cd bdn nhfl sau:

- Modul ldy mau vd ve do thi;

- Md dui giao tiep, dilu khiln ddng co.

Kit qud lay mau cd the dflpc kit xuat Iflu trfl thdnh file excel. Trln eo sd file ehfla kit qud nay ta cd the sfl dung eho cdc nghiin cflu khdc.

Trln ca sd do thi dd ve vd so sdnh gifla cdc dd th;

khdc nhau ta se ddnh gid dflpc khd nang tdi cfla d ddi vdi moi loai dau bdi tron nhat djnh.

Thu^t gidi cua chflOng trinh dflpc trinh bdy trong hinh 11.

Giao diln chflong trinh dflpc trinh bay trln hinh 12. Ba thflc nghiem khdo sdt bieu dd dp suat bdi tron thuy dpng ddi vdi ddu vistra 300, thdng sd CO bdn:

- Dd nhdt eua dau: 0,015 Pa.s;

- Khdi Iflpng rilng eua dau: 0,880kg/dm3;

- Tdi trpng: 5kg, 10kg, 15kg;

- Tdc dp quay cfla true: 1350 vdng/phut.

Cdc kit qud thflc nghiim trln hinh 13.

H Inh 12 Gia o d en

1

/ 1

:hiiOng

\

\

trii h

•: z n V. 1. -:; i: •( « -s i: i

Kl

i a,Tai troni; Skg toe dp qua\' cua true 1350 vong/phiit

I 1

1

^^, \ \

V \

I z t: •: s -v. t -t -i: -v. r. u: »: ::: 2:

b.'Iai trong 10kg toe do quay cua true 1330 \-6ng,''phut

\ X

1 ./

/ \, A

\

t

s

_I

a:

Hinh 11: Thudt todn chflOng trinh dilu khien

c.Tai trpng 15kg tdc dd quay cua true 1350 vdng/phut Hinh 13: Cdc kit qua thflc nghiim

TAP CHi CO KHi V I £ T NAM • Sd 5 (Thang 5 nam 2012)

NGHIEN cflu TRAO D6I

W,

7 '

Hinh 14: Bieu dd dp sudt d thuy dpng Iy thuylt Tren hinh 14 la biiu dd ap suat thuy dpng ly thuyet. Kit qua thflc nghiim eho thay bieu dd dp suat d dd thuy ddng do trln chu vi d khi thay ddi tdi trpng. Ap suat thuy ddng xuat hien trong khoang do gdc tfl 1300 d i n 2350, tham ehilu vao do thi dp suat Iy thuyet ta thay cd sfl phu hpp cua thflc nghiem vd ly thuylt. Biiu dp sfl dung dau do sd cho tdn sd lay mau Idn n i n net ve gan nhfl lien tuc khdng cd hien tflpng dflt gay trln bieu dd, so sanh vdi dau do ca ed sd dilm do han c h l (hinh 7), biiu dd sfl dung dau do co cd sai sd ldn hon rat nhilu so vdi vile sfl dung dau do sd.

Mat khdc, khi tai trpng thay ddi tdng tfl 5kg - 15kg bieu dd dp suat thflc nghiem tflOng flng vdi cdc c h l dp tai trpng cflng thay ddi theo hfldng bieu dd md rpng hon 25% vd gid tri cflc dai cung Idn hon 25%. Dilu do cd nghia la Iflc tdc dung lln d tang thi dp suat thuy dpng tren d eung tang theo cdn bang vdi ngoai Iflc tdc dung.

3. KET LUAN

Vdi ylu cau cap thilt ciaa viec tfl ddng hda vd viec hien dai hda cdc thilt bi thi nghiem ciia ngdnh ma sat, bdi trOn, viec flng dung dau do sd

vao thilt b} khdo sdt biiu do dp suat vdo d dd thfi dpng d?it dflpc kit qud sau:

Thilt k l c h l t^o thdnh cdng thilt bj khao sa biiu dd dp suat d dd thuy dpng sfl dung dau do si bao gdm cum d thuy dpng bdi trOn fldt va mad lay tin hi|u, xfl ly tin hilu, giao tilp mdy tinh, dili kliiln vi tri.

- Xay dflng dflpc ehflong trinh dilu khiln tren mdy tinh eho p h i p khdo sdt bieu do dp suat 6 do thuy dpng, cd khd nang kit xuat file dfl lieu, ve_do thj phuc vu eho cac nghiin cflu trong Iinh vflc bdi tron.

- Giai quylt tri^t d l van de tfl ddng hda thilt bj do dp suat d dd thuy dpng trong phdng thi nghiem bdi tron.

- Kit qua thflc nghiim cho thay bieu dd dp suat thuy ddng phu hpp vdi Iy thuylt va thay ddi khi thay ddi tdi trpng. •

Tdi lieu t h a m khao:

til. GS.VS. Nguyen Anh Tuan, PGS. Pham Van HiiDg

• Ma sat hpc, NXB Khoa hpc Ky diugit. Ha Noi, 2007.

[2]. PGS. Nguyen Doan Y - Giao trinh Ma sat Mon Boi tron Tribology, NXB Khoa hpc Ky thuat. Ha Npi, 2007.

[3). TS. Bui Quy Lflc - H | thdng dilu khiln sd, NXB Khoa hpc Ky Uiu^t, Hd Ndi. 2007.

[4]. Nguyin Xudn Todn - Cdng nghe bdi trdn, NXB Khoa hpc Ky thudt. Ha Npi, 2009.

[5]. Trinh Chat - Co Sd Thiet k l May va Chi tilt 1 ^ . NXB Khoa hpc Ky tiiudt, Hd Npi, 2008.

[6]. Mark Healy, Kelvin Muspratt - HydrauUc Lubrica- tion System, Central Queensland University, 1994.

17]. Peter J. Blau, Metals and Ceramics Division - Oat Ridge National Laboratory, 1992

TAP C H l CO K H i VIET NAM • Sd 5 (Thang 5 nam 2012^