đồ án thiết kế máy

Trng HBK TPHCM N CHI TIT MY - 2011

SVTH: Trn ng Khu GVHD: PGS.TS Nguyn Hu Lc 2

LI NI U

t nc ta ang trn pht trin, do khoa hc k thut ng mt vai tr quan trng

trong cng cuc cng nghip ha, hin i ha t nc. Vic p dng khoa hc k thut chnh l

lm tng nng sut lao ng, thay th sc lao ng ca ngi lao ng mt cch c hiu qu nht,

bo m an ton cho ngi lao ng trong qu trnh lm vic. to nn tng tt cho bc pht

trin trong tng lai, chng ta cn u t, nghin cu, gio dc, pht trin khoa hc k thut mt

cch nghim tc ngay t trong cc trng i hc.

n mn hc Chi Tit My l mt mn hc gip sinh vin ngnh Ch To My c bc

i chp chng, lm quen vi cng vic thit k m mi ngi k s c kh s gn cuc i mnh

vo . Hc tt mn hc ny s gip cho sinh vin mng tng ra c cng vic tng lai, qua

c cch nhn ng n hn v con ng hc tp ng thi tng thm lng nhit huyt, yu

ngh cho mi sinh vin. Khng nhng th qu trnh thc hin n s l th thch thc s i

vi nhng k nng m sinh vin c hc t nhng nm trc nh v c kh, k nng s dng

phn mm: Autocad, Autocad Mechanical, Autodesk Inventor cng vi nhng kin thc trong

nhng mn hc nn tng: Nguyn l my, Chi tit my, Dung sai v K thut o

Trong qu trnh thc hin n, chng em nhn c s ch dn rt tn tnh ca thy

PGS.TS Nguyn Hu Lc cng cc qu thy c khc trong Khoa. S gip ca cc thy c l

ngun ng lc ln lao c v tinh thn cho chng em trn con ng hc tp, rn luyn y gian

lao vt v.

Do y l bn thit k k thut u tin m chng em thc hin nn chc chn s mc phi

nhng thiu xt, sai lm. Em rt mong nhn c s gp chn thnh t pha cc thy c. Em xin

chn thnh cm n.

Sinh vin thc hin

Trn ng Khu



Mc lc LI NI U ................................................................................................................................. 2

Phn mt: Tnh ton chn ng c v t s truyn: ....................................................................... 4

1.1. Tnh ton chn ng c: ......................................................................................................... 4

1.2. Phn phi t s truyn v tnh ton ng hc h dn ng xch ti:.......................................... 5

Phn hai: Tnh ton b truyn ai: ................................................................................................. 7

2.1. Thng s ban u: .................................................................................................................. 7

2.2. Tnh ton thit k b truyn ai: ............................................................................................. 7

Phn ba:Thit k b truyn trong hp gim tc ............................................................................. 9

3.1 Tnh ton b truyn cp nhanh: .......................................................................................... 9

3.2 Tnh ton b truyn cp chm:.......................................................................................... 15

Phn bn: Kim tra bi trn ngm du........................................................................................ 23

Phn nm:Thit k trc ................................................................................................................ 24

4.1 Thit k trc 1:....................................................................................................................... 24

4.2 Thit k trc 2 ........................................................................................................................ 28

4.3 Thit k trc 3:....................................................................................................................... 32

Phn su: Kim nghim then ........................................................................................................ 35

Phn by: Chn ln v ni trc.................................................................................................. 39

I Trc u vo 1:....................................................................................................................... 39

II Trc trung gian 2: .................................................................................................................. 41

III Trc u ra 3:....................................................................................................................... 43

IV Chn ni trc vng n hi: ................................................................................................. 46

Phn tm: Thit k v hp v cc chi tit ph .............................................................................. 47

Phn chn: Chn du bi trn v dung sai lp ghp .................................................................... 50

TI LIU THAM KHO ............................................................................................................. 53



Phn mt:

TNH TON CHN NG C,PHN PHI T S TRUYN.

1.1. Tnh ton chn ng c:

1.1.1. S liu ban u: H thng truyn ng bng ti lm vic c cc thng s sau:

- Lc vng trn bng ti: F = 2500 N

- Vn tc bng ti: v = 1,25 m/s

- ng knh tng dn: D = 400 mm

- Thi gian phc v: L = 7 nm

H thng truyn ng bng ti quay 1 chiu, lm vic 2 ca, ti va p nh (1 nm lm vic

280 ngy, 1 ca lm vic 8 gi).

1.1.2. Xc nh cng sut cn thit ca ng c:

Cng sut trn trc ng c in c xc nh theo cng thc:

tct

PP

(theo (2.8))

Trong : Pct - cng sut cn thit trn trc ng c, kW;

Pt - cng sut tnh ton trn trc my cng tc, kW;

- hiu sut truyn ng.

Hiu sut truyn ng:

3 30, 99 0,99 0,97 0,96 0,95 0,85K ol brc brt d (theo (2.9))

vi: K - hiu sut ni trc n hi ; ol - hiu sut 1 cp ln; brc - hiu sut 1 cp bnh rng

cn; brt - hiu sut 1 cp bnh rng nghing; d - hiu sut b truyn ai, tr s ca cc hiu sut

trn tra theo bng 2.3.

H thng truyn ng bng ti lm vic vi s ti trng nh sau:



Theo (2.12) v (2.13), cng sut lm vic trn trc my cng tc: 2 2 2 2

1 21 2

1 2

0,83..12 .60. 2500.1,25. . 2,69

1000 1000 12 60t td

T T T Tt tF v T T T TP P kW

t t

Khi : 2, 69 3,1650,85

tct

PP

kW.

1.1.3. Xc nh s b s vng quay ng b ca ng c:

Theo (2.17) , s vng quay ca trc my cng tc:

= 60000 vD= 60000. 1, 25

.400= 59,68 vng/pht

trong : v - vn tc bng ti, v = 1,25 m/s;

D ng knh tang dn, D = 400 mm.

T bng 2.4 , ta chn t s truyn ca hp gim tc bnh rng cn - tr hai cp 12hu ;

4du , do s vng quay s b ca ng c theo (2.18) nh sau:

12 4 59, 68 2864,64sb lv tn n n vng/pht

Chn s vng quay ng b ca ng c 3000dbn vng/pht.

1.1.4. Chn ng c:

Theo bng P1.3 vi 3,165ctP kW v 3000dbn vg/ph ta dng ng c DK51-2 c

4,5dcP kW, 2900dcn vng/pht.

1.2. Phn phi t s truyn v tnh ton ng hc h dn ng xch ti: 1.2.1. Phn phi t s truyn:

Chn loi hp gim tc bnh rng cn tr 2 cp:



T s truyn ut ca h dn ng: 2900 48,659,68l

dct

v

nun

(theo (3.23))

trong : dcn - s vng quay ca ng c chn, 2900dcn vng/pht;

lvn - s vng quay ca trc my cng tc, 59,68lvn vng/pht.

Phn phi t s truyn ca h dn ng: 59,68t h xu u u (theo (3.24) )

Suy ra: 4 248,6 1

d

thu u

u

Da vo hnh 3.20 , ta chn t s truyn cp nhanh ca hp gim tc 1 4u v t s truyn

cp chm ca hp gim tc 2 3u .

Tnh li gi tr ca du theo tu trong hp gim tc: 1 2

48, 63

44

td u u

uu

Vy ta chn 4du

1.2.2. Xc nh cng sut, mmen v s vng quay trn cc trc:

32,69 2, 720,99

lv

K

PP

kW; 322,72 2,86

. 0,96 0,99brt ol

PP

kW

21

2, 68 2,98. 0,97 0,99brc ol

PP

kW; 1 2,98 3,17. 0,95 0,99dc d ol

PP

kW

2900dcn (v/p) ; 12900 725

4dc

d

nnu

(v/p); 121

725 181,254

nnu

(v/p)

23

2

181, 25 60, 423

nnu

(v/p)

6 3,179,55 10 10439,142900dc

T Nmm ;

61

2,989,55 10 39253,79725

T Nmm

62

2,869,55 10 150692, 41181, 25

T Nmm ;

63

2,729,55 10 429923,8760, 42

T Nmm

BNG PHN PHI T S TRUYN

Trc

Thng s

ng c I II III

Cng sut P, kW 3,17 2,98 2,86 2,72

T s truyn u 4 4 3

S vng quay n, vng/pht 2900 725 181,25 60,42

Mmen xon T, Nmm 10439,14 39253,79 150692,41 429923,87



Phn hai:

TNH TON B TRUYN AI 2.1. Thng s ban u: - Cng sut truyn n: 3,17P kW - S vng quay: 2900dcn vng/pht

- T s truyn: 4u

2.2. Tnh ton thit k b truyn ai: Bc 1. Chn tit din ai:

Vi cng sut v s vng quay nh trn ta chn ai tit din A (hnh 4.1).

Bc 2. Chn cc thng s c bn ca b truyn ai:

Theo bng 4.13 chn ng knh bnh ai nh 1 125d mm.

Vn tc ai 1 1 .125.2900 18,9860000 60000

d nv m/s ( nh hn vn tc cho php max 25v

m/s)

Theo cng thc 4.2, vi 0,02 , ng knh bnh ai ln

2 1(1 ) 4.125.(1 0,02) 490d ud mm

Theo bng 4.26 ng knh tiu chun 2 500d mm

Nh vy t s truyn thc t:

2

1

500 4,08(1 ) 125.(1 0,02)tdu

d

V sai lch

( ) (4,08 4) .100% 2% 4%4

tu uuu

Theo bng 4.14 chn s b khong cch trc 20,95. 0,95.500 475a d mm, theo cng

thc 4.4 chiu di ai: 2 2

2 11 2

( ) (500 125)2 0,5 ( ) 2.475 0,5 (125 500) 2006( )4 4.475

d dl a d d mma

Theo bng 4.13 chn chiu di ai tiu chun: 2000l mm.

Theo 4.15 nghim s vng chy ca ai trong 1s: 18,98 9,492

vil



vi : 2000 0,5 (125 500) 1018, 25

2 1 500 125 187,52 2

d d

Theo 4.7 gc m 2 11 min57( ) 57.(500 125)180 180 135 120

471,87d d

a

Bc 3. Xc nh s ai: Theo cng thc 4.16

1

0

3,71.1,35 1,63[ ] 3,01.0,88.1,04.1,14.0,98

d

l u z

PKzP C C C C

Trong : Theo bng 4.7, 1,35dK Vi 1 135 ta chn 0,88C (bng 4.15)

Vi 0

2000 1,1761700

ll chn 1,04lC (bng 4.16)

Vi 4u ta chn 1,14uC (bng 4.17)

Vi 18,98v m/s, 1 125d mm, chn 0[ ] 3,01P kW (bng 4.19)

Vi 10

3,71 1, 23[ ] 3,01PP

ta chn 0,98zC (bng 4.18)

Ly 2z ai.

Chiu rng bnh ai, theo 4.17 v bng 4.21

( 1) 2 (2 1).15 2.10 35B z t e mm

ng knh ngoi ca bnh ai:

02 125 2.3,3 131,6ad d h mm

Bc 4. Xc nh lc cng ban u v lc tc dng ln trc:

Theo 4.19 1780. 780.3,71.1,35 37,83 154,7818,98.0,88.2

da v

PKF FvC z

N

Trong : 2 2. 0,105.18,98 37,83v mF q v N (bng 4.22)

Theo 4.21 lc tc dng ln trc :

10

1352 sin( ) 2.154,78.2.sin( ) 5722 2r

F F z

N



Phn ba:

THIT K B TRUYN TRONG HP GIM TC

3.1 Tnh Ton B Truyn Cp Nhanh Cc thng s ban u

Cng sut u vo: 1 2,98P kW Moment xon: = 39253,79 S vng quay: = 725 / T s truyn: u = 4 Thi gian phc v: 7 nm Quay mt chiu, lm vic hai ca ( 1 nm lm vic 280 ngy, mt ca 8 gi) Ch ti: = , = 0.83

= 12 , = 60

1) Chn vt liu:

Ta chn vt liu cho cp bnh cn rng thng nh sau:

+ Bnh nh : Thp 45 ti ci thin t rn b mt HB = 270,

c 1b=850(MPa);

1ch=580(MPa).

+ Bnh ln : Thp 45 ti ci thin t rn b mt HB =255,

c 2b=750(MPa);

2450ch (MPa).

2) Xc nh ng sut cho php : Tnh s b ng sut un v ng sut tip xc cho php theo cc cng thc

6.1a v 6.1b ta c:

0lim.[ ] F HLH

H

Ks

;

0lim. .[ ] F FC FLF

F

K Ks

.

Trong : limoF ,

0limH : ln lt l ng sut un v ng sut tip xc cho php ng vi s chu

k c s, tr s ca chng c tra bng 6.2: lim 1,8oF HB v 0 lim 2 70H HB

Fs , Hs : ln lt l h s an ton khi tnh v un v tip xc tra bng 6.2 1, 75Fs v 1,1Hs

Khi :

1

0lim 2 220 70 610H (MPa)

1

0lim 1,8 270 486F ( MPa)

2

0lim 2 255 70 580H (MPa)

0lim 2 1,8 255 459F (MPa)

FcK : H s xt n nh hng t ti ,ly 1FcK (ti trong t mt pha)



HLK , FLK : H s tui th, c xch nh theo cng thc 6.3 v 6.4:

HHOm

HLHE

NKN

;

FFOm

FLFE

NKN

y: Hm , Fm : Bc ca ng cong mi khi th v tip xc v un vi HB 350 ly:6; 6H Fm m FON , HON : S chu k thay i ng sut c s khi th v un v tip xc

+ FON = 4.106 vi tt c cc loi thp

+ 2,430HO HBN H

7

7

10.97,1

10.05,2

2

1

HO

HO

N

N

+ HEN , FEN : s chu k thay i ng sut tng ng V b truyn lm vic ch ti trng thay i nhiu bc nn theo cc cng thc 6.7 v 6.8

ta c:

260 . .

Hm

iHE i i

TN c n tT

; 60 . .Fm

iFE i i

TN c n tT

vi: c l s ln n khp trong mt vng quay ca bnh rng, c = 1

in , it : S vng quay v thi gian lm vic ch i

Ta c:

3 3 81 1

1 5N 60 1 725 31360 (1 0,83 ) 8, 77 10 N6 6HE HO

1 1HLK

3 3 82 2

1 5N 60 1 181, 25 31360 (1 0,83 ) 2,19 10 N6 6HE HO

2 1HLK

6 6 81 1

1 5N 60 1 725 31360 (1 0,83 ) 8, 77 10 N6 6FE FO

1 1FLK

6 6 82 2

1 5N 60 1 181, 25 31360 (1 0,83 ) 2,19 10 N6 6FE FO

2 1FLK

Nh vy:

1610 1 554,5

1,1H (MPa);

2

580 1 527,31,1H

(MPa)

Vi bnh cn rng thng ta c:

1 2min ; 527,3H H H MPa ;

1486 1 1 277,7

1,75FMPa ; 2

459 262,31,75F

MPa

ng sut qu ti cho php, theo cc cng thc 6.13 v 6.14 ta c:

max 2[ ] 2,8 2,8 450 1260 MPaH ch

1max 2[ ] 0,8 0,8 580 464 MPaF ch

2max 2[ ] 0,8 0,8 450 360 MPaF ch



3) Xch nh chiu di cn ngoi: Theo cng thc 6.52a ta c:

12 32

.1.

(1 ). . .[ ] H

e Rbe be H

T kR k u

k k u

Trong : 0,5R dk k : H s ph thuc vo vt liu bnh rng v loi rng,vi truyn ng

bnh cn rng thng bng thp 100dk (MPa)1/3

130,5 100 50 MPaRk

u: T s truyn cp nhanh ca hp gim tc, u = 4

T1: Mmen xon trn trc dn ( T1 = 39253,79N.mm)

beK : H s chiu rng vnh rng, ly 0,285beK

HK : H s k n s phn b ti trng khng u trn chiu rng vnh rng tra

bng 6.21 vi : . 0, 285.4 0,662 2 0,285

be

be

K uK

, do trc lp trn a ta c: 1,15HK

Suy ra:

23

2

1,1550 4 1 120, 4(1 0, 285) 0,285 4 527

3925,3

3,79 eR mm

4) Xc nh cc thng s n khp : ng knh chia ngoi ca ca bnh cn ch ng c xc nh theo cng thc 6.52b:

131 2 2 2

. 2. 2 120, 4. 58,4(1 ). . .[ ] 1 4 1

H ee d

be be H

T K Rd K mmK K u u

Tra bng 6.22 ta c 1 16pz vi 1 1350 1,6 1,6 16 25,6pHB z z .

ng knh trung bnh v modun trung bnh ca bnh cn nh:

1 1(1 0,5 ). (1 0,5 0,285) 58,4 50,08m be ed K d mm

1

1

50,08 1,9625,6

mtm

dm mmz

Modun vng ngoi c xc nh theo cng thc 6.5:

1,96 2,291 0,5. 1 0,5 0, 285

tmte

be

mm mmK

Theo bng 6.8 ly gi tr tiu chun 2,5tem mm do :

(1 0,5. ) 2,5 (1 0,5 0,285) 2,13tm te bem m K mm

11

50,08 23,52,13

m

tm

dzm

ly 1 24z (rng)

2 1 1 4 24 96z u z rng.



Do t s truyn thc t 211

96 424

zuz

Gc cn chia :

' ''11

2

24arctan arctan 14,04 14 210, 4896

ozz

' ''2 90 14, 04 75,96 75 57 36

o

Theo bng 6.20 vi 1 24z ta chn h s dch chnh u 1 0,39x ; 2 0,39x

ng knh trung bnh ca bnh nh: 1 1 . 24 2,13 51,12m tmd z m mm

Chiu di cn ngoi:

2 2 2 21 20,5. 0,5 2,5 24 96 123,69e teR m z z mm

5) Kim nghim rng v bn tip xc :

Theo cng thc 6.33 ta c:

21

21

2. . . 1. . [ ]0,85. . .

HH M H H

m

T K uZ Z Zb d u

Trong :

mz : h s k n c tnh vt liu ca bnh rng, theo bng 6.5 ta c 13274mz MPa

z :h s k n s trng khp ca rng ,c xc nh theo cng thc 4z

3

y l h s trng khp ngang, c tnh theo cng thc:

1 2

1 11,88 3, 2 cos( ) 1, 71z z

(vi 0 ); 4 1,71 0,8743e

z

Hz : H s k n hnh dng b mt tip xc,theo bng 6.12 ta c 1,76Hz

1T : Mmen xon trn trc dn 1 39253,79 T Nmm

HK : H s ti trng khi tnh ton v tip xc, c xc nh theo cng thc 6.61

. .H H H HVK K K K

y:

HK : H s k n s phn b ti trng khng u trn chiu rng vnh

rng 1,15HK



HK : H s k n s tp trung ti trng khng u trn gia cc rng ly

1HK

HVK : H s xt n nh hng ca ti trng ng, tnh theo cng thc 6.63

1

1

. .1 2

H mHV

H H

v b dKT K K

Trong : 10.( 1). . mH H

d uv g vu

vi: 1. . 3,14 51,12 725 1,94 /60000 60000

md nv m s . Theo

bng 6.13 ta chn cp chnh xc b truyn l 8. H l tr s k n nh hng ca sai s n khp

,theo bng 6.15 vi dng rng thng th 0,006H . 0g l h s k n nh hng ca sai lch

bc rng ,theo bng 6.16 vi cp chnh xc mc lm vic m l 7 th 0 47g . Suy ra:

51,12 (4 1)0,006 47 1,94 4,374H

v

b : chiu rng vnh rng, . 0, 285 123,69 35, 25be eb K R ly 35b mm .

Vy 4,37 35 51,121 1,092 39253,79 1 1,15HV

K

Do 1,09 1,15 1 1, 25 HK .

Vi cc tr s va tm c ta c:

2

22 39253,79 1,25 4 1274 1,76 0,874. 480,77

0,85 35 51,12 4HMPa

Theo bng 6.1 th [ ] [ ] . . . H H sb R v xHz z K

Trong :

vz : H s k n nh hng ca vn tc vng, vi 1,94 / 1vv m s z .

Rz : H s xt n nhm b mt, vi 2,5 1,25 0,95a RR m z .

xHK :H s xt n nh hng ca kch thc bnh rng, vi 700 1a xHd mm K [ ] 527,3 1 0,95 1 500,94H MPa

Ta thy [ ]H H .

Vy iu kin bn tip xc c m bo.

6) Kim nghim rng v bn un:


11

1

2. . . . .0,85. . .

F FF

tm m

T K Y Y Yb m d

Trong : FK : H s ti trng khi tnh ton v un, c tnh theo cng thc 6.71 . .F F F FvK K K K



Vi FK l h s xt n tp chung ti trng khng u trn chiu rng vnh rng, theo

bng 6.21 ta c 1, 24FK , FK l h s xt n tp trung ti trng khng u gia cc rng 1FK , FvK l h s xt n nh hng ca ti trng ng, xc nh theo cng thc:

1

1

. .1 2

F mFV

F F

v b dKT K K

Vi : 10.( 1). . mF F

d uv g vu

theo bng 6.15 v 6.16 ta c: 0,016F ; 0 47g

51,12 (4 1)0,016 47 1,94 124F

v 12 35 51,121 1, 242 39253,79 1 1,15FV

K

Vy 1,24 1,24 1=1,54FK 1 1 0,6

1,71Y

0

1 1140

nY

11

1

24 24,74os( ) os(14,04)vn

zzc c

22

2

96 395,71os( ) os(75,96)vn

zzc c

1 0,39 x ; 2 0,39x Tra bng 6.18 ta c: 1 3,48FY ; 2 3,63FY

Vy 12 39253, 79 1,54 0, 6 1 3, 48 77,93

0,85 35 2,13 51,12FMPa

22 1

1

3,6377,93 80,983, 48

FF F

F

Y MPaY

Ta thy :

22

11

FF

FF

Vy iu kin bn un ca cp bnh rng cn c m bo.

7) Kim nghim rng v bn qu ti.

Theo cng thc 6.48 ta c: ax ax

[ ]Hm H qt H mK

vi: 480,77 H MPa ; 1,4qtK

max max480,77 1,4 526,66 [ ] 1260 H HMPa s MPa

Theo cng thc 6.49 ta c: ax ax[ ]Fm F qt F mK

max1 1 1 max77,93 1,4 109,102 [ ]F F qt FK MPa

max 2 2 2 max80,98 1, 4 113,37 [ ]F F qt FK MPa

Vy bn qu ti ca rng c tha mn.



8) CC THNG S V KCH THC CA B TRUYN BNH RNG CN: Chiu di cn ngoi 123,69eR mm

Modul vng ngoi 2,5tem mm Chiu rng vnh rng 35wb mm T s truyn

1 4u

Cp chnh xc 8 Gc nghing ca rng 00b

S rng ca cc bnh rng 1 224 ; 96z z

H s dch chnh chiu cao rng 1 20,39 ; 0,39x x

ng knh chia ngoi :

ed

1 1. 2,5 24 60e ted m z mm

2 2. 2,5 96 240 e ted m z mm Gc cn chia: 0 0

1 214,04 ; 75,96

Chiu cao rng ngoi : eh 2 2, 2 5,5e te te teh h m c m mm Chiu cao u rng ngoi : aeh

1 1( .cos ). (1 0,39 1) 2,5 3,475 ae te n teh h x b m mm 2 1 2. . 2 2,5 3,475 1,525 ae te te aeh h m h mm

Chiu cao chn rng ngoi : feh

1 1 5,5 3,475 2,025fe e aeh h h mm 2 2 5,5 1,525 3,975fe e aeh h h mm

ng knh nh rng ngoi :

aed 1 1 1 1 2. .cos 66,74ae e aed d h mm 2 2 2 2 2. .cos 240,74 ae e aed d h mm

3.2 Tnh Ton B Truyn Cp Chm: Cc thng s ban u

Cng sut u vo: 1 2,86P kW Moment xon: = 150692,41 S vng quay: = 181.25 / T s truyn: u = 3 Thi gian phc v: 7 nm Quay mt chiu, lm vic hai ca ( 1 nm lm vic 280 ngy, mt ca 8 gi) Ch ti: = , = 0.83



= 12 , = 60

1) Chn vt liu: Ta chn vt liu cho cp bnh tr rng nghing nh sau:

+ Bnh nh : Thp 45 ti ci thin t rn b mt HB = 270, c

1b=850(MPa);

1ch=580(MPa)

+ Bnh ln : Thp 45 ti ci thin t rn b mt HB =255, c

2b=750(MPa);

2450ch (MPa)

2) Xc nh ng sut cho php : Tnh s b ng sut un v ng sut tip xc cho php theo cc cng thc 6.1a v 6.1b ta c:

0lim.F Hl

HH

ks

;

0lim . .F Fc Fl

FF

k ks

Trong : limoF ,

0limH : ln lt l ng sut un v ng sut tip xc cho php ng vi s chu

k c s, tr s ca chng c tra bng 6.2: lim 1,8oF HB v 0 lim 2 70H HB

Fs , Hs : ln lt l h s an ton khi tnh v un v tip xc tra bng 6.2:1, 75Fs v 1,1Hs

Khi :

0 lim1 2 260 70 590F MPa 0 lim 2 1,8 260 468F MPa 0 lim 2 2 250 70 570H MPa

2Flin = 1,8.250 = 450(MPa) 0

lim1 1,8 250 450 MPaH

FcK : H s xt n nh hng t ti ,ly 1FcK (ti trong t mt pha)

HLK , FLK : H s tui th, c xch nh theo cng thc 6.3 v 6.4

HHOm

HLHE

NKN

; F FOmFLFE

NKN

y:

Hm , Fm : Bc ca ng cong mi khi th v tip xc v un vi HB 350 ly:6; 6H Fm m

FON , HON : S chu k thay i ng sut c s khi th v un v tip xc

FON = 4.106 vi tt c cc loi thp

2,430HO HBN H

7

7

10.97,1

10.05,2

2

1

HO

HO

N

N

HEN , FEN : s chu k thay i ng sut tng ng



V b truyn lm vic ch ti trng thay i nhiu bc nn theo cc cng thc 6.7 v

6.8 ta c:

260 . .

Hm

iHE i i

TN c n tT

; 60 . .Fm

iFE i i

TN c n tT

vi: c l s ln n khp trong mt vng quay ca bnh rng, c = 1, in , it : S vng quay v thi

gian lm vic ch i.

Ta c:

3 3 81 1

1 5N 60 1 181,25 31360 (1 0,83 ) 2,19.10 N6 6HE HO

2

1HlK

3 3 72 2

1 5N 60 1 60,42 31360 (1 0,83 ) 7,3.10 N6 6HE HO

1

1HlK

6 6 81 1

1 5N 60 1 181, 25 31360 (1 0,83 ) 1,5.10 N6 6FE FO

2

1FlK

6 6 72 2

1 5N 60 1 60, 42 31360 (1 0,83 ) 5.10 N6 6FE FO

1

1FlK

Nh vy: 1

590 1 536,361,1H

(MPA); 1

570 1 518,181,1H

(MPA)

Vi bnh tr rng nghing theo cng thc 6.12 ta c:

1 2

1 536,36 518,18 527,272 2H H H

(MPa) 21, 25H H

1486 1 1 277,7

1,75F

(MPa);

2

450 1 257,141,75F

(MPa)

ng sut qu ti cho php ,theo cc cng thc 6.10 v 6.11 ta c

Hmax = 2,8.ch 2 = 2,8.450 = 1260(MPa)

F1max = 0,8. ch 2 = 0,8.580 = 464(MPa)

F2max = 0,8.ch 2 = 0,8.450 = 360(MPa)

3) Xch nh cc thng s c bn ca b truyn : Xc nh s b khong cch trc theo cng thc 6.15a

2

32 22

. .( 1)

. .H

w aH ba

T ka k u

u

Trong :

+ ak : H s ph thuc vo vt liu ca cp bnh rng v loi rng.Theo bng 6.5 ta c 1/3 43 ak MPA

+ 2T : Mmen xon trn trc hai ca hp gim tc, = 150692,41 + H ng sut tip xc cho php ,

1/3527, 27 MPaH + 0,3ba tra theo bng 6.6



+ Hk H s k n s phn b ti trng khng iu trn chiu rng vnh rng khi ti v tip xc.

Theo bng 6.7 vi bd 0,64 , ta c 1,03Hk (s 5)

Suy ra: 3w 21, 0343 (3 1) 164, 7

51506

27, 27 3 0,392, 41a

(mm) ly w 165a mm

Ta c: w 2 0,3 165 49,5ba wb a mm v w1 w2 5 55b b mm

4) Xch nh cc thng s n khp Theo cng thc 6.17 ta c:

(0,01 0,02) (0,01 0,02) 165 1,65 3,3 wm a mm

Theo bng 6.8 chn mdul php 2,5m mm

Chn s b 010 , do 0cos( ) cos(10 ) 0,9848 , theo cng thc 6.19 ta xc nh

c s rng bnh nh: 1 wos( ) 0, 98482 2 165 32,5

( 1) 2,5 (3 1)cz a

m u

ly 1 32z

rng.

S rng bnh ln c xch nh theo cng thc 6.20: 2 2 1z u z 3 32 96 ly

2 96z rng >

Do t s truyn thc l 221

z 96 u 3z 32

1 2

w

32 96os( ) 2,5 0,972 2 165z zc m

a

0 14,14 14 8 28

Theo cng thc 6.18 ta tnh li khong cnh trc:

1 2w

32 962,5 1652 os( ) 2 0,97

z za mc

(mm)

Ta s dng rng khng dch chnh x1 = x2 = 0

Gc n khp

0tw

tanarctan 20,57 20 34'3''

ost c

5) Kim nghim rng v bn tip xc: Theo cng thc 6.33 ,ng sut tip xc trn b mt lm vic ca rng l

12

w w1

2. . ( 1). .. .

HH M H

T K uz z zb u d

Trong :



+ mz : h s k n c tnh vt liu ca bnh rng, theo bng 6.5 ta c 274mz (MPA)1/3

+ Hz : H s k n hnh dng b mt tip xc, theo cng thc 6.34 ta c 2.cos

sin(2. )b

Htw

z

y: b :Gc nghing ca rng trn hnh tr c s


0 0cos cos 20,57 14,14 0, 236b ttg tg tg 013,27b

Do ta theo cng thc trn ta c 2.cos(13,27) 1,72sin(2.20,57)H

z

+ z: H s k n s trng khp ca rng . Xc nh theo cng thc 6.36c:

Ta c wsin sin 14,14

. 0,3 165 1,54 1. 2,5

bm

Do ta c 1 1 0, 771,694

z

Trong 1 2

1 11,88 3, 2 os( ) 1, 694cz z

ng knh vng ln bnh nh: w

w11652 2 82,5

1 3 1ad

u

(mm)

+ HK : H s ti trng khi tnh v tip xc ,tnh theo cng thc 6.39 . .H H H HVK K K K

Vi + HK :H s k n s phn b khng u ti trng trn chiu rng vnh rng, tra bng

6.7 ta c 1,03HK + HK : H s k n s phn b ti trng khng u gia cc i rng ng thi n khp

,tr s ca kH c tra theo bng 6.14 ta c 1,03HK + HVK : H s k n nh hng ca ti trng ng trong vng n khp, theo cng thc 6.41 ta c:

1

1

. .1 2

H w wHV

H H

v b dKT K K

Trong : 10

.( 1). . wH Hd uv g v

u

+ H : H s k n nh hng ca sai s n khp theo bng 6.15 ta c 0,002H + 0g : H s k n nh hng ca sai lch bc rng,ly 0 47g theo bng 6.16

+ v : Vn tc vng 1 1. . 3,14 82,5 181,25 0,7860000 60000

wd nv (m/s). Theo bng 6.13 ta chn

cp chnh xc cho b truyn l 9.

H82,5 4v 0,002 47 0,78 0,67

3



Vy ta c: 0,67 49,5 82,51 1,0092 150692, 41 1,03 1,03HV

K

1,03 1,03 1,009 1,07HK

Thay s vo cng thc trn ta c :

2

2 150692,41 1,07 (3 1)247 1,72 0,77 409,9549,5 3 82,5H

(MPa)

Xc nh chnh xc ng sut tip xc cho php:

vi 5 / 1vv m s z

2,5 1 ,25 ( ) 0,95a RR m z

700 1a XHd mm K

Theo 6.1 v 6.1a ta c:

[ ] [ ] 527,27 1 1 1 0,95 500,1H H sb v a XHz z K MPa

Ta thy 409,95 [ ] 500,1H H vy iu kin bn tip xc c m bo. n

gin trong qu trnh tnh ton ta ly w 50b (mm).

6) Kim nghim rng v bn un


1 11

1

2 F FF

w w

T K Y Y Yb d m

Trong :

+ 1T :mmen xon trn bnh ch ng, N.mm + m : modul php + wb : chiu rng vnh rng w 50b (mm) + 1wd :ng knh vng ln ca bnh ch ng, mm

+ 1 1 0,591,694

Y

h s k n s trng khp ca rng (vi 1,694 )

+ 01Y

140

:h s k n nghing ca rng 01 14,14Y =0,899

140

+ YFi : H s dng rng ca bnh 1 v 2

vi

1v1 3 3

2v2 3 3

z 32z 35,06 cos 0,97

z 96z 105,19

cos 0,97

Vy theo bng 6.18 vi h s dch chnh 1 2x x 0 Ta c F1 F2Y 3,75 ; Y 3,60

+ KF: H s ti trng khi tnh v un . .F F F FVK K K K

y:



+ FK : H s k n s phn b ti trng khng u trn chiu rng vnh rng khi tnh v un ,theo bng 6.7 ta c 1,09FK

+ FK : H s k n s phn b ti trng khng u gia cc rng khi tnh v un ,theo bng 6.14 ta c 1,12FK

+ FVK : H s k n nh hng ca ti trng ng 1

1

. .1 2

F mFV

F F

v b dKT K K

vi 0. . . wF Fav g vu

Tra bng 6.15 v 6.16 ta c: + F 0,006 + 0 47g

1650,006 47 0, 78 1, 613F

v

Vy ta c: 1, 61 50 82,51 1, 02

2 150692, 41 1, 09 1,12FvK

1,02 1,09 1,12 1,245FK Ta c

+ 12 150692,41 1,245 0,59 0,899 3,75 72,37

50 82,5 2,5F

(MPa)

+ 22 11

3,672,37 69,483,75

FF F

F

YY

(MPa)

Ta thy

22

11

FF

FF

Vy iu kin bn un c m bo

7) Kim nghim rng v bn qu ti

Theo cng thc 6.48 ta c: Hmax H H max [ ]qtk

vi: 409,95 H MPa ; max 1, 4qtTkT

Suy ra: max max409,95. 1,4 485 [ ] 1260H HMPA MPa

max max. [ ]F F qt Fk

Suy ra: Fmax1 = F1.kqt = 72,371,4 = 101,32(MPA) < F1max

max1 1 1 max. 72,37 1, 4 101,32 [ ]F F qt Fk MPA

Fmax2 F2 qt F2 max.k 69,48 1, 4 97, 27 MPA [ ] Vy bn qu ti ca rng c tha mn.



8) Cc thng s v kch thc ca b truyn bnh tr rng nghing Khong cch trc 165wa (mm)

Mul php 2,5m (mm)

Chiu rng vnh rng 1

2

5550

w

w

bb

(mm)

T s truyn 3u

gc nghing ca rng 0 14 8 28

S rng ca bnh rng 1 2z 32 ; z 96

H s dch chnh 1 2 0x x (mm)

Cp chnh xc 9

ng knh vng chia :d

11

22

. 2,5 32 82, 47 cos 0,97

. 2,5 96 247,42cos 0,97

m zd mm

m zd mm

ng knh nh rng :da

1 1

2 2

2 82, 47 2 2,5 87, 47

2 247, 42 2 2,5 252, 42a

a

d d m mm

d d m mm

ng knh y rng :df

1 1

2 2

2,5 82, 47 2,5 2,5 76, 22

2,5 247,42 2,5 2,5 241,17 f

f

d d m mm

d d m mm



Phn bn:

KIM TRA BI TRN NGM DU

iu kin bi trn ngm du trong hp gim tc cn tr :

- Bnh rng cn cn c ngm ht chiu rng bnh rng ln h trong du.

- Bnh rng tr rng nghing cn ngm ht chiu cao rng rh v ti thiu l 10mm.

- Mc cao nht ca du khng vt qu 13

R mi bnh rng.

- Khong cch gia mc du cao nht v thp nht: ax min 10...15mh h mm .

1 - Xt bnh rng cn b dn:

Chn chiu cao bnh rng cn b dn cn phi ngm trong du l 12,5 mm.

Nh vy, chiu cao ti a m bnh rng cn cn phi ngm trong du l 27,5 mm.

Nh vy min 92,87H (mm )

2 - Xt bnh rng tr b dn:

Ta thy min2 292,87 126,21 84,143 3banhrangtru

H R

Do b truyn tha mn iu kin bi trn:

- min 92,87H mm

- ax 77,87mH mm



Phn nm:

THIT K TRC

4.1- Thit k trc 1:

Cc thng s ban u

Moment xon: = 39253,79 S vng quay: = 725 /

Thit K

Bc 1. Chn vt liu

Chn vt liu ch to l thp C45 thng ha. Cc thng s:

Gii hn bn: b = 600 MPa Gii hn chy: ch =340 MPa ng sut xon cho php: [ ] = 15 30

Bc 2. Chn s b ng knh

ng knh s b c tnh theo cng thc: 13 0.2 [ ]

Td

.Chn 1[ ] 15 MPa

1 331

1

39253, 79 23, 56 0, 2 0, 2 1 5

Td mm

Ta chn ng knh trc theo dy tiu chun: = 24

Bc 3. Chiu rng ln

T ng knh cc trc ta tra chiu rng ln i vi tng trc theo bng 10.2 sch Tnh ton Thit k h dn ng Trnh Cht-L Vn Uyn trang 189. Trc 1: = 17 .

Bc 4. Tnh ton phc tho cc kch thc di trc

Ta c: = 35 b rng rng bnh rng cn.

Di y l hnh v phc tho cc kch thc ca trc 1. T hnh v ny ta c cc kch thc ca trc 1 nh sau:



11 12,5 3 2,5 17 42,5 l d mm . Chn 11 42 l mm 13 11 1 1 2 13 13 1 0.5 0.5 cosl l b k k lm b

0 42 0,5 17 10 10 35 0.5 35 cos 14, 04

88,5 mm

Chn 13 90 l mm . y:

= 8 15: khong cch gia cc chi tit quay. Chn = 10. = 5 15 : khong cch t mt mt ti thnh trong ca hp. Chn = 10. 13 35lm mm : chiu di mayo bnh rng dn.

12 1 1, 2 1,5 1,5 24 36 lm d mm 12 12 3 1 0.5 0.5 0, 5 36 15 17 0,5 17 58,5nl lm k h b mm

Chn 12 60 l mm . Trong :

= 15 khong cch t mt mt chi tit quay n np = 17 chiu cao np v u bulng.

Bc 5. Tnh ton lc tc dng ln cc trc

Cc lc tc dng ln bnh rng cn dn l:

111

2 2 39253,7951,1

1532

6 tm

TF Nd

1 1 1 1 536 20 cos 14, 04 542,36 r tF F tg cos tg N 1 1 1 1 536 20 sin 14,04 135,63 a tF F tg sin tg N Lc tc dng ln bnh ai l:

101352 sin( ) 2.154,78.2.sin( ) 572

2 2

o

rF F z N



11 151,12. 135,63 3466, 7

2 2m

adM F Nmm



Mt phng Oyz:

1 1 1

1 1 1

1

1

2108.48 .90 .150 82333, 3

2556, 83448, 83

B C t r

B C r

B

C

Y Y F FY Y M F

Y NY N

Mt phng Oxz:

1 1 1

1 1

1

1

572.48 .90 0

1162619,84

B C r

B C

B

C

X X FX X

X NX N

Bc 6. Xc nh ng knh trc

Moment un tng ti cc tit din i:

- 2 212 3466,7 3466,70 A rx ryM M M Nmm

- 2 2 21277194,86 26033,28 81466,42rx ryBM M M Nmm

- 2 212 34320 0 34320C rx ryM M M Nmm

- 2 21 0rx ryDM M M

Moment tng ng ti cc tit din i:

- 12 2 2 2

11 0, 75. 3466,7 0, 75 39253, 79 34171, 08 tdA A AM M T Nmm

- 12 2 2 2

1 1 81466, 420, 75. 0, 75 39253,79 88274,7 tdB B BM M T Nmm

- 2 2 21 12

1 0, 75. 34320 0, 75 39253,79 48306,39 tdC C CM M T Nmm

- 1 12 2 2 2

1 0, 75. 0 0, 75 39253, 79 33994,78t DdD DM M T Nmm Tnh ng knh cc on trc:

- 1 31 334171,08 17,57

0,1 [ ] 0,1 63AtdAMd mm

- 1 31 388274, 7 24,1

0,1 [ ] 0,1 63BtdBMd mm

- 1 31 348306,39 19,72

0,1 [ ] 0,1 63tdC

CMd mm

- 1 31 333994,78 17,54

0,1 [ ] 0,1 63tdD

DMd mm

Chn ng knh cc on trc theo dy tiu chun: 1 18 Ad mm ; 1 25 Bd mm ;

1 25Cd mm ; 1 18 Dd mm ;



4.2 Thit k trc 2:

Cc thng s ban u

Moment xon: = 150692,41 S vng quay: = 181,25 /

Thit K

Bc 1. Chn vt liu





Td

.Chn 2[ ] 20 MPa

2

2 33

2

150692, 33,52 0.2 0, 2

4 20

1Td mm


Bc 3. Chiu rng ln

T ng knh cc trc ta tra chiu rng ln i vi tng trc theo bng 10.2 sch Tnh ton Thit k h dn ng Trnh Cht-L Vn Uyn trang 189. Ta c: = 21


Ta c: = 35 b rng rng bnh rng cn.

Di y l hnh v phc tho cc kch thc ca trc 2. T hnh v ny ta c cc kch thc ca trc 2 nh sau:



22 22 22 10,5 0 51 21 10 55 6, 10ml b kl k .Chn 22 56 l mm

022 2223 13 2 1 56 0,5 51 35 os 75,96 10 95, 0,5 cos 7 5ml cl l b k Chn 23 95 l mm . y:

= 8 15: khong cch gia cc chi tit quay. Chn = 10. = 5 15 : khong cch t mt mt ti thnh trong ca hp. Chn = 10. 2 22 1,5 51lm d mm : chiu di mayo bnh rng tr dn.

23 1 1, 4 1, 4 34 47, 6 lm d mm : chiu di mayo bnh cn b dn.

1 221 22 23 2 2 51 47,3 6 3 10 2 10 21 169,6m ml l l k k b mm Chn 21 170 l mm .

Bc 5. Tnh ton lc tc dng ln cc trc:

Cc lc tc dng ln bnh rng cn b dn l:

2 1 1536 t tF F N

12 542,36 raF F N

12 135,63 arF F N

Lc tc dng ln bnh rng tr rng nghing dn l:

22w

313

22 2 150692, 41 0,97 3654, 29 os

2,5 32t n

TTF Nd

cm z

w3

3

3654, 29 20,57 1414, 22 cos 14,14

t tr

tgF tgF Ncos

3 3 3654, 2 19 920,64, 14a tF F tg tg N

33 382,4. 7920,6 37960,94

2 2m

adM F Nmm



22 251,12. 135,63 3466,7

2 2m

adM F Nmm



Mt phng Oyz:

2 2 3 2

2 2 3

2

2

2118, 29.56 .114 .39 142517,31

5821536

A D t t

A D t

A

D

Y Y F FY Y F

Y NY N

Mt phng Oxz:

2 2 3 2

2 2 2 3 3

2

2

1278,59.56 .114 .39 20660,34

736543

A D r r

A D r

A

D

X X F FX X M M F

X NX N

Bc 6. Xc nh ng knh trc

Moment un tng ti cc tit din i:

- 2 22 0rx ryAM M M Nmm

- 2 222 244683 32592 55307B rx ryM M M Nmm

- 2 2 22278686 1395115200 08rx ryCM M M Nmm

- 2 23 0rx ryDM M M


- 2 22 2 2 2

2 0,75. 0,75 0 0 0d A At AM M T Nmm

- 2 2 22 22

2 0,75. 55307 0,75 150692, 41 141739tdB B BM M T Nmm

- 2 2 222

2 20,75. 0,75 150692, 41 191033 139508t C CdCM M T Nmm

- 2 22 2 2 2

2 0,75. 0 0,75 0 0D DtdDM M T Nmm Tnh ng knh cc on trc:

- 2 32 30 0

0,1 [ ] 0,1 63d

At AMd mm

- 2 32 3141739 28, 23

0,1 [ ] 0,1 63BtdBMd mm

- 2 32 3191033 31,18

0,1 [ ] 0,1 63CtdCMd mm

- 2 3320 0

0,1 [ ] 0,1 63DtdDMd mm

Chn ng knh cc on trc theo dy tiu chun: 2 25 Ad mm ; 2 30 Bd mm ; 2 32Cd mm; 2 25 Dd mm ;



4.3 Thit k trc 3:

Cc thng s ban u

Moment xon: = 429923,87 S vng quay: = 60,42 /

Thit K

Bc 1. Chn vt liu





Td

.Chn 3[ ] 25 MPa

3

33

33429923 44,14

0.2 0, 2 25,87Td mm


Bc 3. Chiu rng ln

T ng knh cc trc ta tra chiu rng ln i vi tng trc theo bng 10.2 sch Tnh ton Thit k h dn ng-Trnh Cht-L Vn Uyn. Ta c: = 25 .


Di y l hnh v phc tho cc kch thc ca trc 3.

32 32 332 3 99 25 10, 75 5 15 90 4,mc nhl l l b k



Chn 32 94 l mm

33 1 33 3 2 0,5 67,5 25 10 10 66, 25 0,5 m kl l b k Chn 33 65 l mm . y: = 8 15: khong cch gia cc chi tit quay. Chn = 10. = 5 15 : khong cch t mt mt ti thnh trong ca hp. Chn = 10. 2 33 2, 2 99lm d mm : chiu di mayo na khp ni

3 33 1,5 67, 5lm d mm : chiu di mayo bnh rng tr b dn. = 15 khong cch t mt mt chi tit quay n np = 17 chiu cao np v u bulng.

Tuy nhin, 33 67 l mm do v tr ca hai bnh rng tr trong hp s (da vo kt cu

trc 2).

Khong cch gia hai ln 31 175l mm

Bc 5. Tnh ton lc tc dng ln cc trc

Cc lc tc dng ln bnh rng tr rng nghing b dn l: 4 3 3654,29 t tF F N

4 3 1414, 22 r rF F N 4 3 920, 6 a aF F N

Lc tc dng ln ni trc n hi l:

32 2 429923,870, 2 0,3 0, 2 0, 2 1322,84130nt k t

TF F ND

44 4247,42. 920, 6 113887, 43

2 2m

adM F Nmm

Mt phng Oyz: 3 3 4

3 4

3

3

2331, 45175 108 269 38819, 36

2110222

A C t nt

C t nt

A

C

Y Y F FY F F

Y NY N

Mt phng Oxz:

3 3 4

3 3 4

3

3

1414, 22108 67 113887, 43

1192222

A C r

A C

A

C

X X FX X M

X NX N



Bc 6. Xc nh ng knh trc Moment un tng ti cc tit din i:

- 2 23 0rx ryAM M M Nmm

- 2 232 2227880 128736 261729B rx ryM M M Nmm

- 2 232 2124347 124340 7rx ryCM M M Nmm

- 2 23 0rx ryDM M M


- 3 32 2 2 2

3 0,75. 0,75 0 0 0d A At AM M T Nmm

- 2 2 23 32

3 0,75. 261729 0, 75 429923,87 455113tdB B BM M T Nmm

- 3 32 2 2 2

3 0,75. 0,75 429923,12 874347 392540,53 C CtdCM M T Nmm

- 3 32 2 2 2

3 0,75. 0 0, 75 429923,87 372325tdD D DM M T Nmm Tnh ng knh cc on trc:

- 3 33 30 0

0,1 [ ] 0,1 50d

At AMd mm

- 3 33 3455113 44,98

0,1 [ ] 0,1 50BtdBMd mm

- 3 33 3392540,53 42,8

0,1 [ ] 0,1 50tdC

CMd mm

- 3 33 3372325 40,07

0,1 [ ] 0,1 50DtdDMd mm

Chn ng knh cc on trc theo dy tiu chun: 3 45 Ad mm ; 3 48 Bd mm ; 3 45Cd mm ;

3 40Dd mm ;

Phn su:

KIM NGHIM THEN Bc 1. Kim nghim theo bn mi.

Ta kim nghim h s an ton :

s =s s

s + s [s]

Trong :



s =

K +

s =

K +

[s] l gi tr ca h s an ton cho php, ly gi tr l 3,nh vy khng cn kim nghim cng ca trc.

Mt khc, ta c :

Gii hn mi un ca thp Cacbon: = 0,436 = 0,436.600 = 261,6MPa

Gii hn mi xon: = 0,58 = 0,58.261,6 = 151,73MPa

V trc l trc quay nn ng sut un thay i theo chu k i xng nn: Gi tr trung bnh ca ng sut php ti tit din j l: = 0 Bin ng sut php ti tit din j:

= =MW

Trong : M = M + M

W : momen cn un, c tnh theo bng 10.6, trc c 2 rnh then.

W =d32

bt d td

Vi gi tr b, t c tra theo d trong bng 9.1

H dn ng xch ti thit k quay 1 chiu nn: Gi tr ng sut php ti tit din j:

= =

2 =T

2W

Trong :

T l momen xon ti tit din j

W : momen cn xon, c tnh theo bng 10.6, trc c 2 rnh then

W =d16

bt d t

d

Vi gi tr b, t c tra theo d trong bng 9.1

H s , : h s nh hng ca tr s trung bnh n bn mi, tra theo bng 10.7, ta c: = 0,05; = 0

H s K ; K c tnh theo cng thc 10.25; 10.26:

K =

K + K 1

K ; K =

K + K 1

K

Vi :

- H s tp trung ng sut do trng thi b mt K = 1,06 ,do trc c gia cng bng tin t nhm R = 2,5 0,63 ng vi gii hn bn = 600MPa.



-H s tng bn K = 2 ,b mt trc c thm Cacbon -Tr s ca h s K ; K tra theo bng 10.12, ng vi rnh then c ct bng dao phay ngn, ta c:

K = 1,76 ; K = 1,54 - , h s k n nh hng ca kch thc cc tit din trc ti bn mi bng 10.10.

Ta lp c bng kim nghim bn mi ca trc nh sau:

Trc V tr tit din Then

1b h t a= m

I

A1 (18) 6 6 3,5 327 899 0,93 0,9 10,6 21,8 25,3 7,9 7,5

B1,C1 (25) x 1533 3068 0,9 0,85 53 6,4 4,9 25 4,8

D1 (18) 6 6 3,5 327 899 0,93 0,9 0 21,8 x 7,8 x

II

A2,D2 (25) x 1533 3068 0,9 0,85 0 0 x x x

B2 (30) 10 8 5 1609 4260 0,88 0,81 34 17,7 7,4 8,7 5,64

C2 (32) 10 8 5 2078 5295 0,88 0,8 67 14,2 3,8 10,8 3,57

III

A3,C3 (45) x 8946 17892 0,83 0,77 14 12 17,2 12,3 10

B3 (48)

14 9 5,5

7960 18817 0,82 0,76 32,9 11,4 7,2 12,7 6,27

D3 (40)

14 9 5,5

4446 10729 0,85 0,78 0 17 x 8,8 x

Nh vy tt c cc h s an ton u ln hn 3. Trc tha iu kin bn mi

Bc 2. Kim tra trc v bn tnh

Cng thc kim nghim c tnh nh sau:

= + 3 [ ]

Vi:

= 0.1

= 0.2

[ ] = 0.8 = 0.8 340 = 272

Trc 1:

1 3

81466,42 52,140,1 25

; 1 339253,79 12,560,2 25

; 2 21 1 13 56,49 272td



Trc 2:

2 3 42,570,113950

28

3

; 2 3

150692,41 22,990,2 32

; 2 22 2 23 58,3 272td

Trc 3:

33261729 23,70,1 48

; 33429923,87 19, 440,2 48

2 23 33 3 41,2 272td Vy cc trc tha bn tnh.

Bc 3. Kim nghim then

Thng s ca then c tra theo bng 9.1a

iu kin bn dp v iu kin bn ct c dng

=2

. . ( ) [ ] = 150

=2. . [ ] = 60

Vi : T : moment xon trn trc ; d : ng knh trc ti tit din s dng then; = 0.8 : chiu di then; h : chiu cao then; t1 : chiu su rnh then;

Ta c bng kim nghim sau:

Trc ng knh d

1 18 6 6 3,5 28 62,3 25,96 18 6 6 3,5 29 60 25

2 30 10 8 5 44 76 23

32 10 8 5 40 78,4 23,54

3 48 14 9 5,5 50 102 26 42 14 9 5,5 80 77 20

Vy cc then u tha iu kin.



Phn by:

CHN LN V NI TRC I Trc u vo 1: Cc thng s ban u

ng knh vng trong d : 1 25 d mm S vng quay ca : 1 725 / n vng pht Quay mt chiu , lm vic 2 ca, ti va p nh.

Thit K

Bc 1. Chn loi ln Lc hng tm ti v tr cc a cn

2 2 21 1 1

22556,83 1162 2808,5 R B BBF X Y N 2 2 2

1 1 12619,8 448,83 765, 28 4C CRCF X Y N

Trc 1 l trc u vo, lm vic tc quay cao, li c bnh rng cn nn u tin dng a cn.

Bc 2. Chn kch thc ln Ta chn s b ln sau ( ph lc P.2.11)

S hiu d (mm) D (mm) B (mm) T (mm) r (mm) C (kN) (kN)

7205 25 52 15 16,25 1,5 13,5 23,9 17,9

Bc 3. Kim nghim kh nng ti ca

V tr t ln nh hnh v

Ta c : 1,5 1,5 13,5 0,36e tan tan



Lc dc trc ti B1:

1 1 1 1 10,83 0,83 0,36 765,28 135,63 93,04aB sC at rC atF F F e F F N

V : 1 10,83 0,83 0,36 2808,5 839,18sB rBF e F N

Do 1 1aB sBF F nn 1 1 839,18sB aBF F N

Lc dc trc ti C1:

1 1 1 839,18 135,63 974,81aC sB atF F F N

V: 1 228,67sCF N

Do 1 1aC sCF F nn 1 1 974,81aC sCF F N

Xt t s ( = 1 do vng trong quay):

1

1

839,18 0,3. 1 2808,5

aB

rB

F eV F

Tra bng 11.4 ta c : 1, 0X Y

1

1

974,81 1, 27. 1 765,28

aC

rC

F eV F

Tra bng 11.4 ta c: 0,4; 0,4 1,67X Y cotan

Ti trng quy c trn :

1 11 1 1 2808,5 0 1 1 2808,5 rB aB tB Q XVF YF K K N

1 11 0,4 1 765,28 1,67 974,81 1 1 1934RC aC C tQ XVF YF K K N

Vi :

= 1: vng trong quay = 1 : h s nh hng nhit = 1: p dng cho ch lm vic ti va p nh, qu ti ngn hn, tra bng 11.3

Nh vy 1 1 B CQ Q nn ta tnh ton theo thng s ti B1.

Chn thi gian lm vic ca a cn l:

15000 hL h

Thi gian lm vic tnh bng triu vng:

16 660 60 725 15000 652,5

10 10 hn LL tr

Kh nng ti ng: 103

1 2808,5 652,5 19626 19, 6 23, 9m

m BC Q L N kN C kN



Trong 103

m do s dng a.

Tui th tht s ca :

10323900 1258,19( )

2808,

5

mCL trQ

6

1

10 28924 6,460

hLL h nam

n

Nh vy a ny cn c thay sau 3 nm lm vic

Bc 4. Kim nghim kh nng ti tnh:

i vi a cn ta tra bng 11.6 ta c:

00 00,5; 0, 22 0, 22 13,5 0 , 92X Y cotan cotan

Theo cng thc 11.9

0 1 0 1 0 1 10,5 2808,5 0,92 93,04 1490B rB aB rBQ X F Y F N F

Nh vy 0 1 02808,5 17 900BQ N C N

Vy tha iu kin ti tnh.

II Trc trung gian 2: Cc thng s ban u

ng knh vng trong d : 2 25 d mm S vng quay ca : 2 181, 2 / 5 n vng pht Quay mt chiu , lm vic 2 ca, ti va p nh.

Thit K

Bc 1. Chn loi ln Lc hng tm ti v tr cc a cn

2 2 2 222 2 736 582 938A ArAF X Y N

22 2 2

2 22 5 1536 162943rD D DF X Y N

Trc 2 c bnh rng cn v bnh rng tr rng nghing nn u tin dng a .

Bc 2. Chn kch thc ln

Ta chn s b ln sau ( ph lc P.2.11)




7205 25 52 15 16,25 1,5 13,5 23,9 17,9


V tr t ln nh hnh v

Ta c : 1,5 1,5 13,5 0,36e tan tan

Lc dc trc ti A2:

32 2 920,6 542,36 378, 24at aaF F F N

2 2 2 2 20,83 0,83 0,36 1629 378, 24 108,5aA sD at rD atF F F e F F N

V : 2 20,83 0,83 0,36 938 280,3sA rAF e F N

Do 2 2aA sAF F nn 2 2 280,3sA aAF F N

Lc dc trc ti D2: 2 2 2 280,3 378, 24 658,5aD sA atF F F N

V: 2 486,7sDF N

Do 2 2aD sDF F nn 2 2 658,5aD sDF F N


2

2

280,3 0,3. 1 938

aA

rA

F eV F

Tra bng 11.4 ta c : 1; 0X Y

2

2

658,5 0, 4. 1 1629

aD

rD

F eV F

Tra bng 11.4 ta c: 0,4; 0,4 1,67X Y cotan

Ti trng quy c trn :



2 22 1 1 938 0 1 1 938 rA aA t AQ XVF YF K K N

2 22 0,4 1 1629 1,67 658,5 1 1 1751rD aD t DQ XVF YF K K N

Vi :


Nh vy 2 2 A DQ Q nn ta tnh ton theo thng s ti D2.


15000 hL h


26 6181, 260 60 15000 163,125

10 105 hn LL tr

Kh nng ti ng: 103

2 1751 163,125 8073 8,1 23, 9m

m DC Q L N kN C kN

Trong 103

m do s dng a.

Tui th tht s ca :

10323900 6077( )

175

1

mCL trQ

6 6

2

10 10 6077 55880460 60 181, 2

5h

LL hn


i vi a cn ta tra bng 11.6 ta c:

00 00,5; 0,22 0,22 13,5 0 ,92X Y cotan cotan

Theo cng thc 11.9

0 2 0 2 0 2 20,5 1629 0,92 658,5 1420D rD aD rDQ X F Y F N F

Nh vy 0 2 016 29 20900DQ N C N


III Trc u ra 3: Cc thng s ban u

ng knh vng trong d : 3 45 d mm



S vng quay ca : 3 60, 42 / n vng pht Quay mt chiu , lm vic 2 ca, ti va p nh.

Thit K

Bc 1. Chn loi ln Lc hng tm ti v tr cc a cn:

2 2 23 3

23 2110 1192 2423rA A AF X Y N

2 2 23

23 3 2222 31422rC C CF X Y N

Ta chn dng a cn (do trc di)

Bc 2. Chn kch thc ln Ta chn s b ln sau ( ph lc P.2.11)


2007109 45 75 19 20 1,5 11,33 40 34,8


V tr t ln nh hnh v

Ta c : 1,5 1,5 11,33 0,3e tan tan .

Lc dc trc ti A3:

3 3 3 3 30,83 0,83 0,3 314 920,6 999aA sC at rC atF F F e F F N

V : 3 30,83 0,83 0,3 2423 603sA rAF e F N

Do 3 3aA sAF F nn 3 3 999sA aAF F N

Lc dc trc ti C3:

3 3 3 603 920,6 318aC sA atF F F N

V: 3 78sCF N



Do 3 3,aC sCF F cng chiu nn 3 3 318 78 396aC sCF F N


3

3

999 0, 41. 1 2423

aA

rA

F eV F

Tra bng 11.4 ta c : 0,4; 0,4 11,30,4 3 2X Y cotan cotan

3

3

396 1, 26. 1 314

aC

rC

F eV F

Tra bng 11.4 ta c: 0,4; 0,4 11,30,4 3 2X Y cotan cotan

Ti trng quy c trn :

3 33 0,4 1 2423 2 999 1 1 2967rA aA tA Q XVF YF K K N

3 33 0, 4 1 314 2 396 1 1 918rC aC C t Q XVF YF K K N

Vi :


Nh vy 3 3 A CQ Q nn ta tnh ton theo thng s ti A3


15000 hL h


6 6360 60 60, 42 15000 54,378

10 1

0hn LL tr

Kh nng ti ng: 103

3 2967 54,378 9839 9,8 40m

m AC Q L N kN C kN

Trong 103

m do s dng a.

Tui th tht s ca :

10340000 5832( )

296

7

mCL trQ

6 6

3

10 10 5832 1608739 60 60 6

0, 42h

LL hn


i vi a bi chn ta tra bng 11.6 ta c:

00 00,5; 0, 22 0, 22 11,3 1 3 1,X Y cotan cotan



Theo cng thc 11.9

0 3 0 3 0 3 30,5 2423 1,1 999 2310A rA aA rAQ X F Y F N F

Nh vy 0 3 024 23 34800AQ N C N


IV Chn ni trc vng n hi: Moment xon ti trc 3 l: 3 429923,87 430T Nmm Nm

Tra bng 16.10a ta c cc thng s ni trc nh sau:

T Nm

d D L l Z B

500 40 170 80 175 110 71 130 8 3600 5 42 30 28 32

Bng 16.10b

l l

14 M10 20 62 34 15 28 1.5

Bc 5. Kim tra sc bn dp:

0 3

2 [ ]d dc

kTZD d l

Trong : [ ] = 3 ng sut dp cho php ca cao su. = 1,2 : h s ch lm vic

2 1,2 2,53 [ ]8 130 14 2

429923,878

d d

Vy ni trc tha sc bn dp.

Bc 6. Kim tra sc bn ca cht:

03

0

[ ]0.1

u uc

kTld ZD

Trong :

[ ] 80u MPa ng sut cho php ca cht.

20 1

153 4 41,52 2ll l

3

1,2 429923,87 41,5 75 [ ]0,1 14 8 130

u u

Vy cht tha iu kin bn.



Phn tm:

THIT K V HP v CC CHI TIT PH

I- Thit k v hp gim tc:

V hp gim tc c nhim v m bo v tr tng i gia cc chi tit v cc b phn ca my, tip nhn ti trng do cc chi tit lp trn v truyn n, ng du bi trn v bo v cc chi tit trnh bi.

Vt liu ch to v hp l gang xm, GX15-32

Chn b mt lp ghp gia np hp v thn hp i qua ng tm cc trc lp cc chi

tit thun tin v d dng hn. B mt ghp song song vi mt .

Mt y hp nghing mt gc t 10 v pha l tho du nhm thun tin hn trong vic tho du: du bi trn c thay th sch s, tng cht lng lm vic cho hp gim tc.

Hp gim tc c c cc thng s c bn sau:

Tn gi Thng s Chiu dy:

Thn hp Np hp 1

10mm 1 0,9 9mm

Gn tng cng Chiu dy e

8e mm

ng knh: Bulon nn 1d Bulon cnh 2d Bulon ghp np bch v thn 3d Vis ghp np 4d Vis ghp np ca thm 5d

1 14d mm

2 10,7 10d d mm

3 20,8 8d d mm

4 20,6 6d d mm

5 20,5 5d d mm Mt bch ghp np v thn: Chiu dy bch thn hp 3S Chiu dy bch np hp 4S B rng bch np v thn 3K

3 31,8 14,4S d mm

4 30,9 13S S mm

3 2 3 29K K mm

Mt hp: Chiu dy khng c phn li 1S B rng mt hp 1,K q

1 11,4 20S d mm

1 42 , 65K mm q mm Kch thc gi trc B rng mt ghp bolon cnh 2K

2 2 2 3 16 13 3 32K E R mm



Tm l bulon cnh 2E 2 22 2

1,6 1,6 10 16 ;1,3 1,3 10 13

E d mmR d mm

Khe h gia cc chi tit Gia bnh rng vi thnh hp Gia nh bnh rng ln vi y hp 1 Gia mt bn cc bnh rng vi nhau

10mm

1 3 30mm

10mm S lng bulon nn Z

200L BZ

Np :

Cc np vi thng s ca vis ghp, ng knh np : Trc 1

Trc 2 Trc 3

D 52 52 85

2D 80 65 100

3D 94,4 80 125

4D 42 42 75 h 8 8 10

4d M8 M8 M8 Z 4 4 6

II- Thit k cc chi tit ph: 1. Bulon vng:

Ren d 1d 2d 3d 4d 5d h 1h 2h Trng lng nng

c a

M10 45 25 10 25 15 22 8 6 200

2. Cht nh v: Chn cht nh v hnh cn.

3. Ca thm: (bng 18.5)



A B A1 B1 C C1 K R Vis SL

100 75 150 100 125 - 87 12 M822 4

4. Nt thng hi: (bng 18.6)

Chn nt thng hi M272:

A B C D E G H I K L M272 15 30 15 45 35 32 6 4 10

M N O P Q R S 8 22 6 32 18 36 32

5. Nt tho du: (bng 18.7)



Chn nt tho du c kch thc:

d b m f L c q D S D0 M202 15 9 3 28 2,5 17,8 30 22 25,6

6. Mt ch du: (bng 18.9) Kch thc que thm du nh sau:

Kch thc mt knh (mm) D Dl l h 20 55 40 10 6

Phn chn:

CHN DU BI TRN v DUNG SAI LP GHP

I. Du bi trn hp gim tc:

Chn nht ph thuc vo vn tc vt liu ch to bnh rng, tra theo bng 18.11.

Vi vn tc vng trong khong 1 2,5 /m s , vt liu ch to bnh rng l thp C45 ti ci

thin ta tra c nht ca du 050 l 186 .

Tra bng 18-13 ta s dng loi du bi trn AK- 15.

II. Lp bnh rng ln trc v iu chnh s n khp: i vi bnh rng cn, vic iu chnh c tin hnh trn c hai bnh rng dn v b dn.

- Dch chuyn trc cng vi cc bnh rng c nh trn n nh b m iu chnh c chiu

dy khc nhau lp gia np v v hp. Vic iu chnh nh th ny kh thun tin.



- Dch chuyn cc bnh rng trn trc c nh, sau nh v ln lt tng bnh mt. Vic

iu chnh ny kh phc tp.

Lu : iu chnh phi t 70% trn b mt rng.

III. Dung sai v lp ghp: 1. Chn cp chnh xc:

- i vi bnh rng cp chnh xc c chn trong phn trc.

- i vi trc, then v cc rnh then chn cp chnh xc l 7.

- i vi cc l chn cp chnh xc l 6.

- i vi sai lch ca song song, thng gc, nghing, o mt u, o mt ton

phn l 6, thng, phng l 7, ng tm , i xng, giao trc, o hng tm

ton phn, tr, trn, v profin tit din dc l 5.

2. Chn kiu lp: - i vi then v bnh rng ta chn kiu lp H7/k6.

- i vi vng trong chn kiu lp k6.

- i vi vng ngoi chn kiu lp H7.

3. Bng dung sai lp ghp bnh rng:

Chi tit

Mi

lp

es

( m ) ei

( m ) ES

( m ) EI

( m ) di

ln nht (

m )

h

ln nht (

m )

Bnh cn

dn 76

Hk

+12 +1 +18 0 12 17

Bnh cn b

dn 76

Hk

+15 +2 +21 0 15 19

Bnh tr

dn 76

Hk

+18 +2 +25 0 18 23

Bnh tr b

dn 76

Hk

+18 +2 +25 0 18 23

4. Bng dung sai lp ghp ln:

Mi lp es

( m ) ei

( m ) ES

( m ) EI

( m ) di ln nht

( m ) h ln nht (

m )

25 6k +15 +2 0 -10 25 -



45 6k +18 +2 0 -12 30 -

52 7H 0 -15 +30 0 - 45

75 7H 0 -15 +30 0 - 45

5. Bng dung sai lp ghp then: ( bng 20.6)

Kch thc tit

din then b h

Sai lch gii hn chiu rng rnh

then

Chiu su rnh then

Trn trc Trn bc

Sai lch gii hn

trn trc 1t

Sai lch gii hn

trn bc 2t P9 D10

6 6 -0,042 +0,078 +0,030

0,1 0,1

10 8 -0,051 +0,098 +0,040

0,2 0,2

14 9 -0,061 +0,120 +0,050

0,2 0,2



TI LIU THAM KHO:

1. Trnh Cht - L Vn Uyn - Tnh ton thit k h dn ng c kh tp I v II- Nh

xut bn Gio Dc 2007.

2. Nguyn Hu Lc C s Chi Tit My NXB HQG TPHCM 2010.

3. Nguyn Trng Hip Chi Tit My Nh xut bn Gio Dc 2008.

4. Ninh c Tn Dung Sai v Lp Ghp Nh xut bn gio dc 2009.

5. P.OrLov - Fundamentals of Machine Design MIR Publishers. Moscow.

6. Jack M.Walker Manufacturing Engineering Marcel Dekker . NewYork

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