1THIT B THY KH

CHNG 3 BM V NG C TH TCH

2NI DUNG

1. Khi nim c bn

a. c im

b. Phn loi

c. Thng s lm vic

2. Bm piston

a. Cu to, nguyn l lm vic

b. c im thy lc

3. Bm rotor

4. Bm piston - rotor

3Khi qut v bm thy lc

Thay i th tch lm vic p nng cht lng thay i

p sut lm vic c th t gi tr rt ln

nu lm kn tt v vt liu bn

Hiu sut cao v H1,

q, Qlt , Q, Qt Lu lng tc thi dao ng p sut dao ng

My thy lc thun nghch

Bm th tch khng phi mi

BmBm

C nngC nng

ng c thy lcng c thy lc

Phn loi bm thy lc

4

Bm

Bm cnh dn Bm th tch

Bm Piston - Roto

Hng trc

Hng knh

Bm bnh rng

Bnh rngngoi

Bnh rngtrong

Trc vt

Bm cnh gt

Bm c bit

Khi qut v bm thy lc

4.Hiu sut CKQ .

Lu lng trung bnh l thuyt: Qlt = q.n

Lu lng trung bnh thc t: Q =Q.Qlt

pH 2.Ct p

Cc thng s c bn

BB

p . Q

N

Lu lng ring q th tch cht lng my cp trong 1 chu k lm vic (1 vng quay)

1.Lu lng

3.Cng sut bm

D c D CN p Q Cng sut ng c thy lc tnh theo thng s c bn :

F p S D C D CQM p

D CN F v DCN M

Ch : ng c thy lc thng s u ra :

MomenLc

ng c thy lc

Phn tch bm thy lc l tng

V d: Mt bm bnh rng c lu lng ring l 12,5 cm3 /vng, quay s vng

quay 1800 vng/pht, p sut ti ca ra ca bm l 16 MPa. Gi s bm l tng (b

qua tn tht), xc nh lu lng l thuyt ca bm, cng sut ca bm.

p p:

Lu lng l thuyt ca bm:

6 4 31800. 12,5 10 3,75 10 / 22,5 l/ph60

Q q n m s

Cng sut ca bm:

5 637,5 10 16 10 6000N Qp W

8NI DUNG

1. Khi nim c bn

a. c im

b. Phn loi

c. Thng s lm vic

2. Bm piston

a. Cu to, nguyn l lm vic

b. c im thy lc

3. Bm rotor

4. Bm piston - rotor

Bm piston tc dng n

Bm piston tc dng n

3 46 5 21

TD C 2

a

B A

po

xs=2R

A

R L

D

2.; ; 24Dq Ss S s R

Lu lng ring:

Bm piston tc dng n

x = AA = OA OA = (R + L) - (R.cos +Lcos )

1,0

TLR

DOA A

R

x

L

s=2R

x

xR(1-cos ) ; =t

v=R..sint a=R.2.cost

Xc nh lu lng tc thi: Qt = Sv

Bm piston tc dng n

max

260

60lt

nSRQnQ Ss

Qt=S.R..sint

hm sin

Qt

Q

S.R

S.R

Qlt

H s khng u v lu lng:

Bm piston tc dng kp

Bm piston tc dng kp

A B

D

d

2

1 4

3

tri phi

kep c2 2

c

q 2S-S .s

.D .S ; S4 4

s 2.R

d

c

Q Sv

Q S R sinS-S .sin

t p

t tt

max

lt

Q

Q 2

QSR

(S-S

c)RQt Qlt

Lu lng ring:

Lu lng tc thi:

H s khng u v lu lng:

Bm piston tc dng 3

12

3

4

5

2

ba.Dq 3 ; S ; s 2R

4Ss

1 2 t3

0

0

Q Q Q

[sin sin 120

sin 240 ]

t t tQ

SR

max

lt

2. .Q 60Q 33

60

nSR

nSs

Qt

SR

Q3t

12

3

4

5

B Ax

s=2R

D

B A

d

D

Q

hm sin

QthQt

S.R

T.v

S.R

T.v

Qt

Qt Q

Bnh iu ho p sut v lu lng

Bnh ln v kn BH ht c pCK trn mt thong BH y c pd trn mt thong

1

Bnh iu ha ht

a)

pckHs

pa

3 Bnh iu ha y

b)

Hpd

p

pck pd

hQN

Q

N

h

H

1 2 1

[n]=(100 200) vg/ph

Hyc-Q

Qlt=q.n

ng c tnh vng quay gii hn [n]

19

NI DUNG

1. Khi nim c bn

a. c im

b. Phn loi

c. Thng s lm vic

2. Bm piston

a. Cu to, nguyn l lm vic

b. c im thy lc

3. Bm rotor

4. Bm piston - rotor

Bm v ng c thy lc rotor

Bm v ng c thy lc bnh rng

Bm v ng c thy lc cnh gt

Bm v ng c thy lc trc vt

Bm chn khng vng ncB

Bm bnh rng

Q 500 lt/php = (1,5 80) MPa] n = 1200 5000 vg/ph]Q=0,7 0,9 ; ck=0,8 0,95; = 0,6 0,85

rng thn khai, xicltz=812 n khp ngoi, trongroto, stato, van an ton

Bm bnh rng n khp ngoi

o1o2

B

A

123

4

A

P H

Do vng c sD vng trn chiaD1 vng trn chn rngD2 vng trn nh rng

b Chiu rng bnh rngh=2m chiu cao ca rngt bc ca rng.m mun ca bnh rng.z s rng gc n khp

2t

h

b

Lu lng ring ca bm bnh rng

V rnh rng V rng2t

hb

; ;2t DV hb t D mz

z

22 2D D bV mb q Dmbz z

2

Q. D.m.b.7 n.7Q

D bQ nz

Lu lng trung bnh thc

q=2.V.z

Lu lng tc thi (t phng trnh momen cn)

20 2MaxL Q Rm m b 2 2max min max2L L Q Rm m L b

zQQQ

2

minmax cos25,1

H s dao ng lu lng:

2 22 ( )tQ Rm m bL f L O2 O1

PRo PA=L

gc n khp ca cp rng (tiu chun =20o)

25

1 2 3

7 6 5

A B

4

D

H

H

D

Lu lng t

p sut thp

c im thy lc ca bm bnh rng

Rnh tho cht lmgtrn stato

Dao ng lu lng

Hin tng kt du chn rng

Fa

Fr

b

Ft

n

F

n Fa

F

Fa

F

Khng in y cht lng

Mn nh rng

O1O2

d

[u]8m/s

Rnh tho cht lmgtrn truc U=R2.

Bm thy lc cnh gt

Thng s k thut

Lu lng : Q 600 lt/php sut : p = 1,5 20 MPabm tc dng kp p=60Mpan = 1000 2000 vg/phQ = 0,8 0,9 ; = 0,5 0,85

lu lng u hn iu chnh c Qkt cu n ginlm vic khng ncht lng lm vic truyn ng thy lc

Phn loiz>2

Tc dng nz=2

Tc dng kp

Tng Q

Khng Q

iu chnh Q

G chn

e

A B

Bung y

Bung ht

Smax

Smin

Smin Smax

q=(Smax-Smin).b.z

q=2e.b(2..R-z.)

stato

roto

2z

Cnh gt

O

Bm cnh gt tc dng n

R

1.Cu to

2.Nguyn l lm vic

3.c im thy lc

Bung ht

Bung y

1

1

e

=>Qmax

Q=0

e,Q

e

A B

Bung y

Bung ht

e,Q

emax

e=0 =>

e Q n=const

( e) Hty -chiu quay bm khng i

AB

Bm 2 cnh gt tc dng n

1- stato; 2 roto; 3 cnh gt; 4 l xo

A B

I II

e

C

1 23

4

e

R1

R2Ro

ca y

ca y

ca ht

ca ht

AB

K

L

C D

M

N

mt cong chuyn tip

stato

roto

Hnh dng thy lc

e

cos

2 21 nzsBRRqcanhgat

nBRRQlt 22212

Gim ti trng tcdng ln trc tng p,Qkhng Qmt trong ca statokhng phi l mttr trn xoay :

R1,R2,mcct

z

2

Bm cnh gt tc dng kp

Bm chn khng vng nc

Re

Roto+cnh gt c nh

Stato

Bung ht

Bung y

T ni cn to chn khng

Ra kh tri

Q=2eB[2(R+e)-z.s].n.Q

Vng nc

Bm hai trc vt

33

Lu lng n nh hn so vi cc loi bm bnh rng.Kt cu nh gn, chc chn, lm vic khng n.

1: V bm; 2: Mt bch; 3,5: ng lt; 4: m lm kn; 6: Trc ch ng; 7: Bnh rng; 8: Trc b ng; 9,10: ; d,f: Rnh

gim ti trng hng trc; A: Ca ht; B: Ca y.

1

ab c B

2 3 4

5 6

8 7

IA I

d9

10

d

f

Bm 3 trc vt

34

1: V; 2: Trc ch ng; 3,4 trc bng; 5 ; 6,7,8: ng lt; 9: m lmkn bm; 10: ng chn; A: ca ht; B: ca y.

Gim ti lc dc trc

d

I-I

D

A

BI

5 8 171082

3

4

I

B

A

1 2 3 4 5

Tng Q

35

Cc thng s lm vic:Lu lng: Q = 1 12000 [l/ph]p sut: p 100 [MPa]

S vng quay: n 18000 [vg/ph]Hiu sut: Q = 0,75 0,95Cng sut N= 1 1500 [kW]

c im thy lc bm trc vt

2 24

q D d t

q th tch rnh ren trong mt bc ren t ca 1 trc vt

i s lng trc vt

2 22 2 4vit QQ D d tn

. .. QQ i q n

36

NI DUNG

1. Khi nim c bn

a. c im

b. Phn loi

c. Thng s lm vic

2. Bm piston

a. Cu to, nguyn l lm vic

b. c im thy lc

3. Bm rotor

4. Bm piston - rotor

Bm v ng c thy lc piston - rotor

37

Bm v ng c thy lc piston - rotor hng knh

Bm v ng thy lc c piston - rotor hng trc

b

a

e

A

B

e

Hd

s=2e

AB

zedq 24

2

StatoRoto

Pttng

Bung y

Bung ht

Vch ngn

L xilanh

Bm pittng rto hng knh

Bm pittng rto hng knh

e

A - AB - BB

B

A

B

a 1 2

3

b

B

A

4

c im thy lc

zedq ..2.4. 2

Lu lng ring

Q=f(e) iu chnh Q m n=const

o chiu chuyn ng cht lng m khng o chiu quay ca ng c

AA

b

a

L xoStatoa nghing Rnh ht, rnh y

PttngRoto

A - A

bm pt tng rto hng trc a nghing

bm pt tng rto hng trc c rotor t nghingD

dDI

123

c im thy lc

42

tgDdzq

4

2

Q=f() iu chnh Q

1 2 3 4

A

B0

0

xs

A

B'0D

I

d

Q=f(-) o chiu chuyn ng cht lng

QtQ

0

Lu lng ring: q 24 [l/vg]

p sut: p = 20 300 [MPa]

S vng quay: n = 1200 3000 [vg/ph]

Hiu sut: = 0,95

Cc thng s lm vic

Lu lng tc thi z=5

e

A Bd

s=2e

zedq 24

2

Stato

Roto

Pttng

Bung y

Bung ht

Vch ngn

L xilanh

Hiu sut ca bm