final and answers 2005 2006 design2 ahmedawad

7
t.-,..:1.i*' -:'1:,;''t": AIN SHAMS UNIVERSITY FACULTY OF ENGINEERING DESIGN & PRODUCTION ENG!NEERING DEPARTMENT Tltird Year Mechanicol, power Section Semester, 2005-2006 Time: 3 Hours The sketch shows the outlines of a gear unit used to operate a 250mm ball valve. The gear unit consists of two stages: . Bevel gear drive fl Parameter Pinion Gear Tooth width, mm 12 12 Velocity fa;tor u., c u., c Service factor 1.15 1.15 Wear stiess factor lVlPa 1.4 1-4 Modified form factor 0.54 - 3tzl Number of teeth 2A 3o Module, mm 2 2 . Worm gear drive Parameter Worm Gear No. of starts 2 llead - helixl anole. deoree 10 10 J-ooth width, mm VelocitV factor o.e 25 0.6 Service factor 1.15 1.15 Lubrication factor 1.2 Wear stress factor. MPa 1.4 1.4 Modified form factor tturnOer otTeettl 0.54 - (3tZ) - -f- 52 Normalmodtrle. mm 3 Coefficient of friction 0.2 0.2 Pressure angle, deqree 20 20 You are reguired to: . lf the driving torque at the valve stem is 400 N.m 1 F nd the driving torque at the operating wheel 2 F nd the bevel gears r1laterials based on static strength only 3 Find the worm gear material based on static strenqth orilu 4 lf the valve is fully closed, what is the number or turns or ftre qpelaling wheel to make the valve fully opened? Find the reactions at the bearing of the driving shaft. 5 6 Present a Free Hand sketch for the gear unit in at ieast two views. Exuniner: Associate ProJ/ Heshant Aly Senbel

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Page 1: Final and Answers 2005 2006 Design2 Ahmedawad

t.-,..:1.i*'-:'1:,;''t": AIN SHAMS UNIVERSITYFACULTY OF ENGINEERING

DESIGN & PRODUCTION ENG!NEERING DEPARTMENTTltird Year Mechanicol, power Section

Semester, 2005-2006 Time: 3 Hours

The sketch shows the outlines of a gear unit used to operate a 250mm ballvalve. The gear unit consists of two stages:

. Bevel gear drive flParameter Pinion Gear

Tooth width, mm 12 12Velocity fa;tor u., c u., cService factor 1.15 1.15Wear stiess factor lVlPa 1.4 1-4Modified form factor 0.54 - 3tzlNumber of teeth 2A 3oModule, mm 2 2

. Worm gear drive

Parameter Worm GearNo. of starts 2llead - helixl anole. deoree 10 10

J-ooth width, mmVelocitV factor o.e

250.6

Service factor 1.15 1.15Lubrication factor 1.2Wear stress factor. MPa 1.4 1.4Modified form factortturnOer otTeettl

0.54 - (3tZ)- -f- 52

Normalmodtrle. mm 3Coefficient of friction 0.2 0.2Pressure angle, deqree 20 20

You are reguired to:. lf the driving torque at the valve stem is 400 N.m1 F nd the driving torque at the operating wheel2 F nd the bevel gears r1laterials based on static strength only3 Find the worm gear material based on static strenqth orilu4 lf the valve is fully closed, what is the number or turns or ftre

qpelaling wheel to make the valve fully opened?Find the reactions at the bearing of the driving shaft.5

6 Present a Free Hand sketch for the gear unit in at ieast two views.

Exuniner: Associate ProJ/ Heshant Aly Senbel

Page 2: Final and Answers 2005 2006 Design2 Ahmedawad

Machine Design-lanuary-2006- ThirdletlMeclaniclal, power section [page: 2/4J

Useful Data

a

a

a

a

a

a

o

a

a

a

Gears Design Equations:

Pt:ob. b. m. K (l- b/L) K:K,.KrlK,Deformation factor : 0.1 I e / flBr+ liE*]Speed factor :2u I [1 + u]Eu: (21 x10a Mpa) F,g1: (l2xl04 Mpa)P.n : 1.2 P6

P.n:o"o.kr.b.mP*:k*.kr.b.Do/cos6P,o: Torque / radius -Prp: P, . tan g . cos 5,Pup: P, . tan o . sin 6o

tanl.:L/nd*:ip/nd*Linear pitch *o* : circular pitch *orrn *"ar

: 7f, rnq : (cos o, - p tanl, ) / (cos o + p coti)P,: Power .\ I v,Pr :Gb.b.m.K K:K,.&/K.K,Pw(womig"u.) : n . k* . b . D*n:2 cos y /ntanyP,,, : Fn . (cos o sin 1, + p cos l,)Pu* : I.o . (cos s cos 1, - psin 1,)D -T]rrw ln.ivUJ (I

a

o

o

a

a

a

a

a

a

e : Probable erTorModdle Commercial Accurate Precision

Up to 4.5 50 25 t26 60 30 l57 70 35 t70 80 40 20t2 100 50 2525 t20 60 30

e^* : Permissible (maximum)enor, [gm]

. \/-Belts Design Eguations:0: 180o + 2s: 1g0o + 2 sin-r LD-d I 2C)

Ansular contact factor (KrL

Fl

F2= gU'O

I 2 t3 4 5 6 :7 8 9 l0 t2 l5 20 25 30 35 40 50125 r00 I es 86 63 55 50 44 39 38 26 ?5 t4 l3 t2 ll IO 9

0r 180 170 160 150 t40 130 t20 ll0 r00 90 80 70Kr 1.0 0.98 0.95 0.92 0.89 0.86 0.82 0.78 0.73 0.68 0.63 0.58

Minimum Pulley diameter (d*). mm:

b 5 6 8 l0 l3 t7 20 22 25 32 40 50h 3 4 5 6 8 II 12.5 t4 t6 20 25 32d- 22 32 45 63 90 125 180 212 250 355 500 7t0

Page 3: Final and Answers 2005 2006 Design2 Ahmedawad

Machine Design-January-2006- Third Year Mecltarical, Power Scctiort [Page: 3/4

5 6 8 l0 13 t7 20 'r) 25 32 40 50

2 0.018 0.037 0.074 0.1 40 0.272 0515 0;136 0.810 l-t04 1.166 2.123 4.416

4 0.03 5 0.014 0.1 40 0.272 0.545 0.957 r.398 t.693 2.208 3.459 5.446 t\.6)Z

6 0.050 0.1 l0 0.206 0.405 0.810 1.398 2.061 2.502 3.238 5.152 8.096 13.25

8 0.063 0 40 0.265 0.530 .030 1.840 2.723 3.238 4.195 6.771 0.30 r6.93

t0 0.014 0 62 0.3 l6 0.640 .251 2.282 )) ll 3.901 5.078 8.1 70 2.51 20.(r I

IZ 0.08 r 0. 84 0.3 53 0.736 .472 2.650 3.827 4.490 5.888 9.421 4.72 T.ss I

l4 0.081 0 9l 0.3 83 0.810 .6t9 2.944 4.269 5.152 6.624 0.60 6.t9 26.50

16 0.081 0. 99 0.412 0.883 .766 3.165 4.637 5.520 7.213 l.56 7.66 28.70

18 0.014 0. 9l 0.412 0.883 .9t4 3.386 4.931 5.888 7.654 2.22 9.14 30.91

2A 0.059 0. 77 0.397 0.957 .987 3.533 5.078 6.035 7.8'15 2.59 9.8'1 i 1.65

22 0.037 0. 55 0.361 0.883 98',7 3.533 5.152 6.109 8.022 2.13 9.87 3 Z.)O

24 0. l0 0.309 0.8 10 .914 3.459 5.005 6.035 7.581 2.51 9.14 )-/..)o

26 0.059 0.221 0.736 1.840 J.JIZ 4.784 5.741 7.434 1.85 8.40 30.1 8

28 0.132 0.66 r.693 3.0r8 4.416 5.226 6.845 0.89 6.93 27.23

30 1.472 3.650 3.754 4.563 5.888 9.s68 4,72 23.55

Strength of some materials(Ultimate and Yield Stress, MFa)

Material ou ov

c22c35c45c60

5506006.60

750

300370400490

st 34st 37st 42

st 50

st 60

st70

340i70420500600700

190

200220250300340

30Mn537MnSi542CrMo 4

36CrNiMo434CrNiMo6'30 Cr Ni Mo 8r

600900980r0001-100

1250

-550800760900900

_10s0

Material ou o,,

cl0ct5

420s00

250300

ccazGG26GG 30

GGG 40

GTW 40

GTW 35

180220260300400400350

::-

250220200

GS 38

GS 45GS 52GS 60

380450520600

..180

220250360

15Cr3l6MnCr518CrNi8

600

8001 200

400600800

Page 4: Final and Answers 2005 2006 Design2 Ahmedawad

Machine Design-Jonuary-2006- Thirct Year Mechanicol, Power Section [Page: 4/4J

Sec. X-X

Note: The vatve is fully closed when the

and fully opened when Point B

Operating wheel

Bevel gears

Ball valve

Bevel gear

point A touches the worm

touches the worm

Driving shaft

Worm

Worm

Cover

Valve stem

Flow-+

Valve stem

gear sector

Cover

Worm

\ \i tI--T---\

I----r---I

Page 5: Final and Answers 2005 2006 Design2 Ahmedawad

,..-,*'.|- - ': atr

--a:: rilt+*

FO t.of t)ottlr Qur

oY:1o

m

0P.

Y\nn- Co56

At-tlf, d*l

tqn?= L'' ?( a*,

J-= Lx \n2

= 2trr ten2

F,=I

,B64oaxlo aL 5o So

t58 .h

(crs r< as2 -/' si'2)

(CosZo Co>lo -o'2 sinlo) ' =

67A N

ft* = (n (c's o1 ein 2 + .la au?)

F'", (Cr, Za 9r'alo + o 'Z Gs lo)

r"Eln

5Fn =

fu,,t'l /

Ft*, = 2o42 N

z4.ss 35 . zb-r k N. *.*4 I = Zo4Z x "-""1 = 5> 'Lo t FN'l^!

[ot7u.e a,L ulo(n = z-on L n -Z

-- N. v,.

in: Arivf,rg -Gv1r..e ^* op"to'ir1 -1trr."{ ? 3s.zb|xZ =

be-ve L Qe-, fl*o,;aL

{orlr.r"L 4eo': t=tzDf = Zx2-o = {o .^*

6f = \";' iA = 33.6s"

D.j = )p -t2 3io a?'69

tr..g = 5o YY\$'\

7^ 2o = zlrrf cos 7?.6?

fif o'4tS

,f.d rnlfo' =5* = 26

\z-= --- = 3.oh6 rir'n

Gs lo

= *.2 a 3, oh6

= -N.vn = ?,57

\ 2 /.-tr re

T xtonlo

x 52 = \58.4 mm

drm

zm = 3,A.ss 'ranfan lo .'J-

d.8s fi

= o.g6 E

sy*/ raib = l'5-Dg

= Zs 3o = 6o Yhm

= ?7.3h Y$q

3o4= #A =31

kJg = o.456

Page 6: Final and Answers 2005 2006 Design2 Ahmedawad

E'r= [i =35287 tz = t4,l

5o

3'o { '*

= SA. 11

7

N

tf" Jriv;,yr 67n' -= 3s ' zb7 n ? = 2z '5 N'"r

t; ls

6i : 325.A rr/.i"r6"^ = q77 Hf*

r

frs*, , duu= 917 x *# = a89 HPa

(l ,,,1o, - 6o, Holu;ot

3Gs lo

5Zr cosT 1o

lrJ = o.Sh -

5o5o

6b =

bu=

[-ta =

s4. 4

6to* 2sx

= a. 48h

- t. o-6 x". qghJ.v1 |

-

t.tS x l.z

= 6.5

26 z Hf*

ls 7 Hf*

Nz' . f furnes ,/, -o'n26

= 4(,u rne)

(9 fo-

N

N

N"- .f t'frnes /' *'"'ty 'lk'y' = 6'5* /'5 = ?'lS

Cos

Sfn

33 .6e

.*^3..69

?tsz

h27

285

Page 7: Final and Answers 2005 2006 Design2 Ahmedawad

"l *a Leadl/:

11I\A =

:

Re=

\'r91.s -- * -C

I 7rilrHFe v.

--> tt ry' d-l x - ze :

Lt

-

I1 L:1oo 6q\ _

F' (t ' 'tFt c'

,rlu

^ -- \

6 ho,5 =\vsfr 2r3'f Y o

22ll6 + 1oS

WN\ , r., =11

G\fr

It.?.

t@\z

@

,i

?._-s43 i zte