truyen dong thuy_khi_t_hoang.pdf

8/10/2019 truyen dong Thuy_Khi_T_Hoang.pdf

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Trng ai Hoc Bach khoa aNng

Truyn ng thuy kh Huynh Vn Hoang 1

TRUYN NG THUYKHcng : Truyn ng thuy Kh

cho sinh vin nganh ng lc(Thi gian 30 tit)------------------------------

- Mn hoc c sphuc vucho cac nganh cohthng trun ng thuylc vakh nen.- Yu cu : Nm c cu tao chc nng vanguyn lylam vic cac phn tthuylc

vas ng dung.- Thi ht mn

- Ni dung :1.Khai nim c ban (2 tit)

1.1.Truyn ng thuy lc lag, phn loai, u nhc im cua truyn ng thuy lc1.2.Cht long lam vic

2. Truyn ng thuy lc thtch (12 tit)2.1.S nguyn lytruyn ng thuy tnh

2.1.1 Chuyn ng tnh tin2.1.2 Chuyn ng quay vong

2.2.S hthng truyn ng thuy tnh2.2.1 S h2.2.2.S kn2.2.3.S vi sai

2.3.Bm vang c thuy lc thtch (nhc lai - xem giao trnh may thuykh )2.3.1 Bm vang c pttng2.3.2.Bm vang c rto2.3.3.Bm vang c pttng-rto

2.4.Cac phn tthuy lc2.4.1 C cu phn phi2.4.2 van mt chiu2.4.3 Van an toan2.4.4. Van giam ap2.4.5. C cu tit lu2.4.6. Btng ap2.4.7.Bn nh vn tc

2.5.iu chnh vn tc c cu chp hanh2.5.1. Phng phap thtch2.5.2. Phng phap tit lu


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tit lu mc tai ca vaotit lu mc tai ca ratit lu mc song song

2.6.n nh vn tc chuyn ng c cu chp hanh

biu tc mc tai ca vaobiu tc mc tai ca rabiu tc mc song song

2.7.Truyn ng thuy lc tuy ng2.8. Mt ss ng dung

3.Truyn ng thuy ng (8 tit)3.1. S nguyn ly, phn loai, may canh dn3.2. Cac phng trnh c ban

3.3. Cac thng sc ban3.4. Khp ni thuy lc3.4.1. Cu tao nguyn lylavic3.4.2. Cac thng s3.4.3. ng c tnh3.4.4. Cac loai khp ni thuy lc

3.5. Bin tc thuy lc3.4.1. Cu tao nguyn lylavic

3.4.2. Cac thng s3.4.3. ng c tnh3.4.4. Cac loai bin tc thuy lc, mrng pham vi sdung bin tc thuylc

3.6. Mt sng dung4. Bai tp (8 tit)

Tai liu tham khao :1, inh Ngoc Ai Thuylc vamay thuylc ,nxb giao duc 19982. Ng Vi Chu Bai tp thuylc vamay thuylc, nxb H vaTHCN, 19763.Nguyn Ngoc Phng Hthng iu khin bng kh nen, nxb giao duc, 19984.M.Guillon : Nghin cu vatnh toan hthng thuylc (ban dch ting Nga ttingPhap), nxb c kh , Mac t khoa 19645. Abramp,... Cac phn ttruyn ng thuylc, nxb kythut , Kiep 1977 (ting Nga)


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I. Nhng khai nim c ban:1.Mun truyn c nng tbphn dn ng n bphn lam vic cua cac may cua cac

thit b, ngoai dn ng bng c kh, in: trong nhng nm gn y ngi ta con dung khnen hoc cht long.

2.Truyn ng thuylc lathp cac c cu thuylc vamay thuylc, dung mi trngcht long lam khng gian truyn c nng tbphn dn ng n bphn cng tac,trong ocothbin i vn tc, lc, mmen, vabin i dang theo quy lut cua chuynng. Truyn ng thuy lc phuhp vi vic truyn cng sut ln, c im m du nnh vadtng hoamacac truyn ng khac khng co.3. Theo nguyn lytruyn ng thuylc chia ra 2 loai:- Truyn ng thuy tnh (Truyn ng thuylc thtch).- Truyn ng thuyng.

+ H truyn ng thuy tnh c truyn nng lng gia cac bphn , c thc hinbng ap nng cua dong cht long, thng dung cac may th tch nn goi la truyn ngthuy lc th tch. Truyn ng th tch c ng dung nhiu trong cac nganh ky thut(Truyn ng thuylc dung may ct kim loai; trong hthng nng, hathuylc; hthngphanh thuylc; hthng trlc tay lai; hthng trong may tuc bin... ).+ Truyn ng thuy ng: truyn c nng gia cac b phn may c thc hin bngng nng cua dong cht long.

c im: Co2 loai: khp ni thuylc vabin tc thuylc, c dung nhiu trong c

kh ng lc.4. u im chuyu cua truyn ng thuylc:(8 u im)- Dthc hin vic iu chnh v cp vatng iu chnh vn tc chuyn ng b

phn lam vic, thc hin ngay khi may ang lam vic.- Truyn ng cng sut lam vic ln.- Cho phep ao chiu chuyn ng bphn, lam vic ddang.- am bao cho may lam vic n nh, khng phuthuc vao s thay i cua tai trong

ngoai.- Kt cu gon nhe, coquan tnh nho, c dung nhiu trong hthng tng.- Do cht long lam vic trong truyn ng thuylc chuyu ladu nn coiu kin bi

trn rt tt cac chi tit.- Truyn ng m hu nh khng n.- Cothphong sckhi may quatai.

5. Nhc im han chpham vi sdung:(3 nhc im)- Vn tc chuyn ng b han chv phai phong sva p thuylc, tn tht ct ap,

tn tht cng sut vaxm thc.- Khokhn lam kn cac bphn lam vic, cht long db ror, hay b khng kh bn

ngoai lot vao lam giam hiu sut vatnh cht n nh cua truyn ng.- Yu cu cht long lam vic rt phc tap.

Edited by Foxit ReaderCopyright(C) by Foxit Software Company,2005-2008For Evaluation Only.


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1. Bm kiu pistonchuyn ng tnh tin.

2

3

5

7

8

10pa

F

Hnh 1

2. ng ng ra cuabm.

3. Van an toan.4. Van phn phi vaccu phn phi.5. ng dn cht longvao xi lanh.6. Xi lanh lc (ng cthuylc).7. ng du hi.

8. ng du vao bm.9. Bloc.10. Thung cha chtlong.

Nguyn ly:- Bm cung cp ap nng cho cht long, cht long i qua c cu phn phi, vao ngn trai

cua xi lanh lc tac ng ln piston lam piston chuyn ng tnh tin.- Cht long ngn phai qua c cu phn phi vthung cha, lam ngui, loc, a vao

bm.- Thung cha thng vi kh tri (ap sut mt thoang pa) goi lahthng h.- Khi quatai, piston sedng lai, ap sut ngn trai tng ln, mvan an toan, cht long ro

r, thao cht long vbcha.Cach tnh toan:1) Vn tc piston:

dtdxv=

2) Lu lng bm cp: QB= vB.SBLu lng bm vao ng c thuylc:

Q= v.SBoqua ror:

QB= QB

B

S

QSQv ==



I

II

III


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Nu boqua tn tht ct ap:

+ Ap sut trong xi lanh cua bmB

B

SFp= c truyn n xi lanh lc vagy ra lc lam

cho piston chuyn ng:

F = p.SS, SB: Din tch lam vic cua piston.+ Cng sut bm: NB= p.QB= FB.VB+ Cng sut ng c thuylc: N= p.Q= F.V N= NB(Truyn cng sut khng mt mat)b. Truyn ng thuy lc cochuyn ng quay:

1- Bm (kiu rto hay piston rto).

1

2

4

3

2- Van an toan.3- Van phn phi (khoa phn phi).4- ng c thuy lc (kiu rto hay piston rto).

Hanh trnh: Tbvao bm vao van phn phi vaong c thuy lc ri trvb. Sau bm covan antoan thao vb.

Q= q.nq

- Lu lng ring cua ng c.

n- Svong quay cua ng c.

n= nBB

qq

Hnh 2 S h

qB- Lu lng ring cua bm

M men ng c: M= n2M

N= p.qn M =

n2n.q.p

=

2q.p

p- Ap sut lam vic-Nhn xet:a. Nu boqua tn tht lu lng, ap sut th vn tc cua ng c (Chuyn ng tnh tinhay quay vong) phuthuc Q,QB. Ngha labin thin lu lng Q, QBth ta cothbin

thin c cu chp hanh.Thc t: Do coror lu lng nn lu lng vao ng c nhohn lng cung cp.

xem lai luu luong rieng cua bompiston roto va roto


N = M.w >> M = N wsa

N = p.Q = p.q.n=w


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Q= QB- QMatn tht lu lng tylvi ap sut:

Q = k.pk- Hsror (Giatr tthc nghim)

v=

B

SQ -

Skp

Nh vy: Vn tc cua ng c trong thc tkhng ch phuthuc vao bm QB maconphuthuc vao ap sut lam vic cua hthng duQB= const nu ap sut trong hthng tngth vn tc cua ng c thuy lc giam. Nu ap sut tng n lu lng ror bng lu lngbm th vn tc cua ng c thuy lc bng 0. Luc nay cht long trong h thng b thaohoan toan qua van an toan vakhe htrong hthng, hin tng nay goi lahin tng quatai.

b. i vi lc vammen cua ng c th chung phuthuc vao ap sut cua ng c vacacthng shnh hoc cua ng c. Nu cac thng shnh hoc khng i vaap sut khng i(p=const) th lu lng vammen quay cung khng i.

Nu bin thin Shoc qbng cac thng scua ng c thuy lc iu chnh c (lch tm...) th lam bin i F vaM. Ngc lai ginguyn yu thnh hoc mabin thinap sut trong ng c nhcac phn tthuy lc trong hthng (Van giam ap, btng ap...)th bin thin c lc vammen ng c.Tom lai: Trong vic iu chnh vn tc, lc, mmen quay cua ng c vtr s, phng

hoc chiu ngoai vic dung bm, ng c coniu chnh c con co th dung c cacphn tthuy lc.

1

2

3

4

5 6

7

8

Hnh 3 S kn

2. Cac loai s h thng: thc hinnguyn ly iu chnh noi trn cac may thuylc vacac phn t thuy lc c ni vi nhaubng cac ng ng. Tuy theo nhu cu lamvic chung ta co th ghep cac mach thuy lctheo 3 loai s sau:S h: (Hnh 2)S kn: Cht long tng c chuyn vng hut cua bm thanh mt vong kn.1- Bm 5- Van phn phi2- Van an toan 6- ng c thuylc3- Tit lu 7- Bm phu8- Van an toan cua hthng bm phu

- Hanh trnh: Cht long tbm n van titlu n van mt chiu n van phn phi n

thay doi theo

dieu chinh duoc


4- van mot c eu


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ng c thuy lc n bmkhc phuc ror ngi ta lp thm bm phuhoc bnh bu- u im: Hthng kn khng cocan thip bn ngoai.Mun at cng sut ln trong truyn ng ngi ta lp tng ap sut bm phu.

Nguyn tc: Lp bnh ni coap sut thp

1

2

3

6

5

Hnh 4

1- Bm 2- Van phn phi3- ng c piston5- Bnh bu6- Van mt chiu

- Nhc im:Nhit cht long lam viccao v cht long sau khi lam vic khngc lam lanh. Ma nhit tng th nht giam dn n ror tng.

S vi sai:

1- Bm (Canh gat).

2

1

5

4

6

3 2- C cu phn phi.3- ng c thuy lc.4- Bnh bucht long.5- Van mt chiu.6- Van iu khin.

Trong s chuyn ng thuy tnh cnmt pha lu lng chay vao vachay ra.

Nu ghep theo s kn th lu lngqua ng hut va y bm khac nhau. khc phuc hin tng nay ngi ta btrthm thung cha phu (4) va ghep manhtruyn ng theo s vi sai.

Hnh 5S vi sai

Bm y cht long qua c cu phn phi (2) piston chuyn ng sang phai qua c cuphn phi vng hut cua bm, luc nay lu lng ra bm nhohn lu lng vao bm, chtlong tthung cha phubsung qua van mt chiu (5) vao ng hut. Luc nay do ap sut

ng y ong van (6) lai. Nu piston chuyn ng ngc (qua trai) cht long tkhoang


mach


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trai vvan phn phi vng hut vamt phn qua van (6) vbcha phu, di tac dungcua ap sut cao van mt chiu (5) ong lai.+ u im: S vi sai giup cho vic iu hoa chuyn ng cua hthng vacon bsunglu lng ror cho hthng.

3 Cac phn tthuy lc:3.1 C cu phn phi:

Dung i nhanh dong chay cac nut trong mt h thng ng ng vaphn phicht long vao ng ng theo mt quy nh nht nh. ng thi cothao chiu cac bphn chp hanh hoc iu khin chuyn ng theo mt iu kin nht nh.

Cht long tbm n ng c thuy lc thng phai qua cac c cu phn phi lani tptrung cac u mi lu thng cht long.

C cu phn phi gm bphn vovabphn i hng dong chay, trn vocokhoet

cac ca lu thng ni vi cac ng ng thuy lc, b phn i nhanh co th di chuyntng i so vi vophn phi vao ca lu thng tuy theo hng dong cua bphn inhanh.

Ngi ta chia lam 3 loai:- Con trt phn phi.- Khoa phn phi.- Van phn phi.Con trt phn phi:

Pbm

F lc iu khin

Voiu khin

Pht

Xi

b - Chiu rngpiston

1

b2- Chiu rngcua lu thng.

b1>b2 : nhaykem.

b2>b1 : nhaythit b tng.Hnh 6 Con trt phn phi

- Piston xi lanh lc chuyn ng sang phai, tn hiu iu khin (bng c kh, in,thuy lc) tac ng ln cn cua piston c cu phn phi.

- Piston xi lanh lc sang trai (tng t).

+ Xac nh nhay:Con trt phn phi: ngn keo


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cng vng tt

Tbm

Ngn keo

Tng c

Hnh 7

Vong chn

Bchang c thuylc

Vo

Khoa phn phi:

thuylc

ng cthu lc

vbcha

Phn quay

ng c

PbmVo

u im: n gian t oi hoi chnh xac.

Nhc im: D ro r, chnh lchap sut cao.

Van phn phi truyn ng thuylc cohngc:u im: Lam kn tt.

Hnh 8 Khoaphn phi

Hnh 9


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3.2 C cu tit lu: Dung iu chnh hoc han chla lng cua cht long trong hthng bng cach gy sc can i vi dong chay.

C cu tit lu cohai loai:a. Tit lu khng iu chnh c:

Cu tao n gian: c b tr trong cac loai may moc gichnh ap cn thitgia hai khoang lam vic.

b. Tit lu iu chnh c:

Bung lam vic

a

b

c

Hnh 10 a. Tit lu khng iu chnh c b,c,d. Tit lu iu chnh c

d

a, b. ong khng kn do va p trong quatrnh ong m.c. ong kn tt nhng nhay cua van kem3.3 Cac loai van:Van laphn tphbin nht trong hthng truyn ng thuy lc,

nhphi hp hp lycac loai van trong hthng chung ta cothtao nn chlam vicn nh theo ymun.Thng thng co3 loai van:+ Van mt chiu.+ Van an toan.+ Van giam ap.a. Van mt chiu:Dung gicho cht long ch chay theo mt chiu, tuy theo hnh

dang cua np van ngi ta cocac tn goi: van bi, van cn, van piston.

b. Van an toan:Dung bao am cho hthng c an toan khi quatai noc lptrn ng ng coiu chnh coap sut cao. Nguyn lyhoat ng cua loai van nay davao scn bng lc tac dung trn np van gia ap lc vi cht long trong h thng vi


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Np van

van

Vt iu chnh

Np

van b

Hnh 11

ng lc cua van. Nu ap lc cht long nhohn ap lc loxo hthng lam vic bnh thngvan ong lai, nu ln hn ap lc loxo hthng quatai van mra thao bt cht long vthung cha.

Co2 loai van:- Van an toan tac dung trc tip.- Van an toan tac dung gian tip.

Van an toan tac dung trc

tip:Khang tr ch m khi quatai.

Tran ch m mt t khi hthng lam vic bnh thng vamht khi quatai

Tt ca cac van mt chiucng hoalc loxo

Van an toan co m giamchn:Cac loai van tac dung trc

tip mc du co bin phapgiam chn nhng van lam vic cung khng n nh lm.

Piston vi sai Vt iu chnh lcHnh 12

Lgiam chn

Mt khac c tnh cua van cung b han chnu ng knh qualn th kch thc loxo tng nhiu. Trong hthng coap sut cao giam ng lc loxo vatng n nhap sut cua hthng ngi ta dung van an toan tac dung gian tip.+ Van an toan tac dung gian tip: Van c mthng qua mt c cu khac.

cong ung o g am c an

van tran


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Khi van khng lam vic: Cht long cocac bung a, b, c, eKhi P>[P] th nomvan an toankiu bi, cht long i ta n d ntit la n e n h n b cha,

ap sut d ln hn ap sut e doomvan an toan chnh cht longt a n b v b cha.Van giamap:Trong mt ngun ap sut phaicung cp cho nhiu ni tiu thuvi yu cu ap sut khac nhau,ngi ta phai dung n van giamap. Van giam ap dung ha ap

sut c cung cp t ngun phuhp vi nhu cu tiu thung thico th gi ap sut ni o khngi.

Van an toantrc tip kiubi

Loxo manhb

e

cV tr ong

aLgiam chn

Thung c

Cohai loai:- Loai trc tip .-

Loai gian tip.

4 Bphn iu tc (n nh tc ):Van giam ap + tit lu5 Btng ap:Dung tng ap sut hanh trnh nao ocua ng c thuylc.

1. Bm.2. Van an toan.3. Van mt chiu.4. C cu phn phi 1.

5 C cu phn phi 2.6. Xi lanh lc.7. Xi lanh tng ap.8. Van mt chiu.

P

P1 = constHnh 14

d

ha

Hnh 13


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Truyn ng thuy kh 14

1

32

4

5

6

7

8

d

D

B cha

Cht lo n

Hnh 15

Khi co b phn tng ap:cht long t bm n c cuphn phi 1 n ng c

thuy lc, c cu phn phi 2n ngn trai xi lanh.

Tng ap P n

4d..P

4D..PF

2

ta

2 =

=

6. Cac bphn phu:6.1 ng dn:Dung dn cht long tbm n ng c thuy lc truyn nng lng.Tuytheo iu kin lam vic cua ng vasror cua cht long tai cac khp ni. Tnh toanng dn ging nh ng thuylc.6.2 Thung cha:Thng thng thtch bng 5 6 ln thtch lam vic.

Trong mt strng hp nng cao hiu sut bm vagiam ting n ngi ta cho bmngp vao cht long cua thung cha, iu nay cothlam tng thtch cua thung. Thtchphn khng kh trn mt thoang cua thung chim khoang (10 15)% thtch cua thung.Cothchon thung kn hoc h.

tng hiu sut cua bm thchon thung kn trn mt thoangcoap sut d.6.3 Bloc du:Dung loc cnbn cua du. Tuytheo chc nng

cua h thng chon cac loc: locthm, loc la, loc li, loc hoahoc hoc loc ly tm.

Khi t hthng loc cn chuy:

- Giam sc can ti thiucua loc i vi dongchay.

- B loc nn b tr trnng ng chnh.

Piston

Hnh 16


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Truyn ng thuy kh 15

6.4 Bnh tch nng: Trong hthng thuylc conhu cu nng lng khac nhau mangunnng lng cua bm th khng i. am bao hthng lam vic bnh thng ngi tadung bnh tch nng.

Bnh tch nng conhim vutrnng lng cua hthng tha khng dung ht vacung

cp nng lng khi vt quayu cu (vt khanng cua bm).Conhiu loai bnh tch nng:

- Trong vt.- Loxo.- Thuylc.6.5 Rle:

- Rle ap sut: thc hin nhim vukhi at giatr nh mc.- Rle thi gian: iu chnh lam vic ng bgia hai thit b theo thi gian quy nh.

7. Phng phap iu chnh vn tc c cu chp hanh:Cac thng sc ban cua truynng thuylc cochuyn ng tnh tin lavn tc piston valc tac dung ln piston.Con trong hthng chuyn ng quay: vn tc quay vammen quayTcac cng thc ahoc chung ta cothiu chnh c 2 phng phap vn tc.- iu chnh thtch lam vic cua bm hay ng c thuylc (phng phap thtch).- Phng phap tit lu: Dung tit lu iu chnh lu lng.

a. Phng phap thtch:Chuyn ng quayn= qp/q.nB

Ta chon nB= const- Thay i qB.- Thay i q.- Thay i qB,q.

Nu: qBth nqth n

Cac thng skhac:

M= p .q/2p= const M= f(q) Nu q thay i khng lam M thay i.Nu thay i lu lng ring: N= q .n.pKhi iu chnh vn tc quay cua r to bng cach thay i lu lng cua bm th cng

sut trn truc ng c tylbc nht vi qB .Nu iu chnh vn tc bng cach thay i qth N= const.* Cach thc thay i lch tm e bm:

ng c thuylc:max

BBB q.

n.q.n

=

=

2 p.q.Mmax

M = N/w = pQ/w= ....


neu qB t ay o o am MD t ay o


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Truyn ng thuy kh 16

maxee

=

Vn tc quay cua r to ng c thuylcphuthuc vao Bva.Kt lun:Khi thay i lu lng cua bm th n= v sethay i t0 (= 0) n max

(= max)Khi thay i qvn tc ng c thuylc thay i t(= 0) max(=1).

Nh vy: Vmt ly thuyt chung ta co th thay i vn tc cua ng c t 0 1.Trong thc tvn tc nkhng that giatr v khi oM= 0. Matrong quatrnh lamvic M phai comt giatr nht nh thng sc can ma sat cua ng c vakeo phutai.

M nhonht ng vi min, min= 0,5Khi iu chnh vn tc quay cua ng r to ng c thuylc bng cach dung bm iu

chnh th vn tc quay cua r to c tng rt cao khng anh hng g n *

Khi iu chnh vn tc quay cua r to ng c thuylc bng cabm vang c thuylc luc u * . Khi ovn tc quay cua ng c thuylc nhonht vaM max (v = 1).Sau otip tuc nng cao vn tc ng c bng cach giam . Vn tc quay vammen cuang c thuylc trong thc tlun lun nhohn giatr lythuyt v khng tranh khoi tntht lu lng.

Vn tc quay thc t: ntt = nlt.QMtt= Mlt.ckhQ = QB .Q .Q

Ror cht long: Q = k.Pk- Hsror.i vi bm: k = (0,05 0,5) cm2/Ns.C cu phn phi: k = 0,002.Xi lanh lc (com lam kn): k = 0.002. Chuyn ng tnh tin:

BP

BmaxBB

P

BP S

QS

n.q.S

QQV ==

Cothiu chnh c vn tc cua piston khi lu lng ln hn lu lng ror. V lu

lng cua bm lun thay i cho phuhp vi ng c thuylc (phutai).Nhc im: Phu tai thay i ro r cht long cung thay i vic iu chnh ng c

cung khokhn. Hthng khng nhay vakhochnh xac nht lai vi hthng lu lngnhophng phap nay nn dung i vi hthng colu lng ln vakhng oi hoi ccu chp hanh hoc lanhng ni phutai t thay i.b. Phng phap tit lu:Thay i sc can lu lng.

gP.g2S.Q =

Phng phap nay khng kinh tv bm lun lun cung cp dung thng c sc cancua tit lu.

KT: ve so o t et uu at o cua vao oac cua ravaf neu nguyen ly( giai thich khi tai trong thaydoi thi v nhu the nao)


kt: Ve so do nguyen ly bo dieu tocviet pt vaf giai thich su thay doi Md va Nd khithay doi qB hoac qD


17/25


- u im: n gian, nhay, chnhxac. c dung cho nhng ni nhay,chnh xac vn tc c cu chp hanh,ngoai ra con iu chnh v cp vn tc

chp hanh.

Van an toankhang

CCPP

Bm

- Nhc im: Tnh kinh t, khngam bao vn tc c cu chp hanh khitai trong thay i. Khi i qua tit lucht long b nong ln nhit chtlong tng lam tng ror hthng .

Co3 cach btr tit lu:-Tit lu t trc xi lanh lc.

-Tit lu t sau xi lanh lc. Hnh 19 Tit lu t song song vi xi lanh lc-Tit lu t song song xi lanhlc. i lanh lc

CCPP Van giam ap

P5

Tit luP5

P4

Bm

F

Hnh 20

*Tit lu t trc xi lanh lc:p = p0 - p1p = p0- p1*

* Tit lu t sau xi lanh lc:Khc phuc hin tng nong ln

p = p2 - p3p1n p1* p1 = const mvanan toan.

P2n p2* p*= p2* - p3* Tit lu t song song vi xi

CA

P

FP

CCPP B

P4P5

CCPP

P5

P2F

P4

Hnh 21 Hnh 22

Truyn ng thuy kh 17

ve so o, g a t c &uu nhuoc



18/25


Truyn ng thuy kh 18

lanh lc:Khi ong tit lu: VpVmaxkhi mtit lu th cht long sen xi lanh lc qua tit

luFth tit lu mV thay i theo tylcht long vao xi lanh lc.

8. n nh vn tc c cu chp hanh:Givn tc cua c cu chp hanh n nh khng phuthuc vao phutai.n nh th lp bphn iu tc theo 3 cach sau:- Li vao.- Li ra.- Song song ng c thuylc.

Hnh 19: g2.PPSQ 54

=

FP1P5y piston van giam ap xung QP4P4- P5= constHnh 20: FP2P2piston ong bt ca van giam ap P4P4 - P5 = const.Hnh 21: FP2PAPBP4ong bt piston P4.

9. Truyn ng theo doi (Tuyng):- Colin hngc kim tra cac thng slam vic

ng c

thuylc

Bphn

so sanh

Bphn

nhn ra lnh

Lin hngc

Bphn

chp hanh

Ngun tac

ng

III. Truyn ng thuyng:Dung hai loai may cach dn: bm li tm vatuc bin cach dnTruyn dng nng lng ttruc dn sang truc b dn:- Khp ni thuylc.- Bin tc thuylc.

1. Khp ni thuylc:Lakt cu n gian nht cua truyn ng vatuyng.Cu tao: Gm 2 banh cng tac: Banh bm vabanh tuc bin.

Nh vy: Mmen quay c truyn ttruc bm sang truc tuc bin cht long sera khoibanh bm vabanh tuc bin valp lai chuyn ng trn mt cach tun hoan mi phn ttrong khp ni thuy lc thc hin ng thi 2 chuyn ng: chuyn ng tun hoan t

banh bm sang banh tuc bin sang banh bm vachuyn ng quay quanh truc khp ni.


19/25


Truyn ng thuy kh 19

Tng hp 2 chuyn ng naycho ta chuyn ng xon ccua cac phn t cht longtrong khp ni thuylc.

Cht long

B ngChung

T B

Hnh 23

2. Bin tc thuylc: Gm 3 banh:

- Banh bm.- Banh tuc bin.- Banh phan ng.Khi cn thay i mmen quay gia truc bm vatruc tuc bin th ngi ta dung bin tc

thuylc, thng dung tng mmen quay gia truc b dn v svong quay cua truc bdn lun lun nho hn s vong quaytruc dn.

Nguyn ly lam vic:Tng t nh

khp ni thuylc.- Banh phan ng co tac dung nhsau:

+ Thay i hng dong chay cho phuhp vi li vao cua banh cng tac tiptheo

+ Thay i tr s vn tc cua dongchay cho phuhp vi li vao cua banhcng tac tip theo. Sd goi laphan ngv cht long khi i qua banh nay truyn cho nomt mmen quay nhng v banh cnhvi vocotac dung nh mt im ta vatruyn lai cho cht long mt mmen ng lng (mmen phan ng).

BD

T

nT nB

Hnh 24

Nu banh phan ng quay th mmen quay cua truc dn truyn qua truc b dn khngthay i khi obin tc thuylc lam vic nh khp ni thuylc.

S khac nhau: Cht long bin tc thuy lc lun lun in y th tch lam vic, conkhp ni thuylc coluc y coluc khng y.

3. Cac thng shthng truyn ng thuyng:

Cng sut lam vic trn truc dn, truc bm:


20/25


Truyn ng thuy kh 20

Truc bm:PB

BBB .

H.v.g.N

=

Truc dn: TBB .H.Q.g.N =

TB

D

1

2

4

3

5 6

D

NT= TT.NB= B.T.P.NBB= (Q.H.CK)B= CKT.QTD.HD

Tystruyn:B

T

nni=

Hsbin tc:B

T

MMK=

N = M.=30

n..M Hnh 25

inn.

NN

MMK

T

B

B

T

B

T ===

Hiu sut: = K.i

Cac phng trnh c ban:

Mmen cua banh bm MB:

MB=2

1 .Q(C2u.D2- C1uD1)

Mmen cua banh truc:

MT=2

1 .Q(C4u.D4- C3uD3)

Mmen cua banh phan ng:

MP=2

1 .Q(C6u.D6- C5uD5)

Q- Lu lng i qua hthng

MB+ MT+ MP= 21

.Q(C2u.D2- C1uD1+ C4u.D4- C3uD3+ C6u.D6- C5uD5)C1u.D6u= C6u.D6uC2u.D2u= C3u.D3u Khng thay i tr smmen ng lng.C4u.D4u= C5u.D5u

MB+ MT+MP= 0Tng ai smmen ng lng quay cua cac banh trong truyn ng thuylc bng 0.Phng trnh mmen:

MB+ MT+MP= 0

Phng trnh ct ap:HB= HT+ht


21/25


Truyn ng thuy kh 21

ht- Ct ap tn tht.ht= htB+ htT+ htBht- Tn tht nhit lam nong cht long lam cho cht tach vabc chay.Tn tht:

- Tn tht do ma sat bmt canh dn, phuthuc: kch thc, hnh dang canh dn, nht dong chay, nham bmt.

- Do sthay i t ngt vphng chuyn ng cua dong chay nht latai cac li vaocac banh (hin tng tach dong chay, va p thuylc ca vao, xoay...).

- Do sthay i nng vn tc dong chay tai cac phn thu hep cac ranh banh cngtac.Trong qua trnh thit k cgng giam tn tht ti thiu nng cao hiu sut b

truyn ng thuyng.

4. c tnh khp ni:- Khp ni thuylc ch truyn mmen quay makhng bin i tr scua noMB+ MT= 0MT= - MB

V vy khi costhay i tai trong trn truc tuc bin svong quay truc tuc bin cungthay i, lam thay i vn tc banh cng tac. Dn n thay i mmen quay cua banh tucbin sao cho cn bng vi mmen quay cua phutai MT= -MB

Khp ni thuylc laloai truyn ng thuyng truyn ap nng ttruc bm sang truc

tuc bin thng qua schuyn ng cht long trong banh cng tac nT< nB.Hiu sgia vong quay cua banh bm vabanh tuc bin chia cho banh bm (s) c goilahstrt cua khp ni thuylc

in

n

n

nns

B

T

B

TB ==

= 11

KNTL= i- Nu s = 0 i = 1 nT= nBth ap sut cht long vi tac dung lc ly tm li ra banh

maxKNTK

MB

NB

NT

Hnh 26

23%n

B=const

M,N


22/25


Truyn ng thuy kh 22

bm vali vao banh tuc bin bng nhau. cht long khng cochuyn ng tng i tbanh bm sang banh tuc bin khi ohthng quay nh vt rn Q = 0 M = 0

- Nh vy khp ni lam vic khi nT< nBs = (2 3)%; = i = (97 98)%

- ng c tnh ngoai: M, N = f(i)(c tnh trong laH-Q)

nb= var ( thay i) c tnh tng hp: Cht long khac nhau 1> 2 > 3 macung mtloai khp ni thuylc.

Cht long in y khac nhau trong khp ni thuylc: 90%in y hoan toan, 10%thoat hi.

1

n

3

2

1

= const maktcu khac nhau

Hnh 27

Vung lam vic khng nnh (cobc nhay)

Hnh 28

M

i


23/25


Truyn ng thuy kh 23

Khi h s trt s = 0 th khng coschuyn ng tng i cua cht long trong cacbanh cua khp ni thuylc.

Cht long

nT nBs = 0

Hnh 29nT

Dong ln

nBs = 0,050,1

Hnh 30

nBs = 0,4 0,45

Hnh 32

Dong nho

nTHnh 31

s = 0,3 0,35 nB nT

Khi tng tai trong cua truc tuc bin s = (0,01 0,05) svong quay banh tuc bin giamgy ra chuyn ng tng i cua cht long trong banh.

Nu s = (0,3 0,35) th cht long coxu hng dch chuyn vbanh tuc bin nhiu hntao thanh vung khep kn rng gia.

Tip tuc tng mmen can s = (0,4 0,45) th vong khep kn seln dn.Sbin i trang thai tvong khep kn nhosang vong khep kn ln xay ra t ngt lam

mmen tng t ngt lam mt n nh chlam vic khp ni.Khc phuc: Lam sao cho cht long ch chuyn ng mt vong. Lp thm trn banh mt

a chn th khp ni thuylc chuyn ng n nh.Phn loai:- Khp ni thuylc cocanh trong vakhng cocanh trong.- Khp ni thuy lc cothiu chnh c vakhng iu chnh c (thay i q).Phn loai bin tc thuy lc:


24/25


Truyn ng thuy kh 24

- Phn loai: 1 cp, 2 cp,3 cp+ 1 cp: co1 canh tuc bin. Phuthuc vao slng banh tuc bin+ 2 cp: co2 canh tuc bin.

- Phn loai: Bin tc thuylc cocanh cnh vabin tc thuylc hn hp.

5. c im bin tc thuylc:Bin tc thuythay i mmen quay (M).Hnh 33

Thay i q

MT+ MB+ MP= 0 (MB> 0)a. Lp banh phan ng P, sau bm B, trc tuc bin T:Tao c dong chay vao banh

tuc bin T lahp lynht.b.Lp banh phan ng sau tuc bin T, sau bm B:

MT= MBHng dong chay ra hp lysong giam cng sut trn B.Khanng tng iu chnh chlam vic. Khi bin tc lam vic ch n nh

th mmen cua banh tuc bin bng mmen can. Nu mmen can ln hn mmen cua banhtuc bin th banh tuc bin quay chm lai, lu lng tun hoan hoan qua cac banh cng tacsetng ln lam tng mmen tuc bin. Khi lu lng tng ln, Phng vn tc tuyt i cavao vaca ra banh cng tac cung tng ln lam tng ap lc cua cht long ln canh dn.

Nu tai trong bn ngoai giam th svong quay banh tuc bin tng, lam giam mmenquay cua banh tuc bin, dn n thit lp trang thai cn bng mi.

Chuy:Mmen quay cua banh tuc bin thay i nh thnao (mmen can quyt nh) th

mmen quay banh bm khng i. iu nay thay i c bng cach thit kcanh dnbanh cng tac vabtr canh dn cho thch hp.

Mmen quay cua banh phan ng MP, thng thng MP= MB- MT , MPthay i khi taitro ng bn ngoai thay i. Ging nh banh tuc bin, ch khac lammen nay thay i cavdu, ngha lathay i vhng tac dung, cuthlahng tac dung cung vi MBMP>0, ngc lai th MB < 0. Con hng MPphuthuc vao bin tc thuylc.

ng c tnh cua bin tc thuylc:


25/25


M

i

BTTL hn hp

KNTL

MBmax

Hnh 34

F phutaiP1P*

CCPP P*

Van an toantran Tit lu

Bm

Tit lu

F phutaiP1P1*

Van an toantran

Bm

CCPP P2

P3

P2P2*

Hnh 18 Tit lu t sau xi lanh lcHnh 17 Tit lu t trc xi lanh lc

truyen dong thuy_khi_t_hoang.pdf

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