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Ain Shams UniversityFaculty of EngineeringDesign & Prod. Ene. De

Third Year Mechanical Power13-June-2001Time allowed :3 hours

Machine Constructi on (2* Students may assume any missine data

The sketch shows the layout of double stage reduction gear unit.The gears were designed according to the data given in the following table.

You are required to:o Estimate the maximum horsepower transmirted by the gears based on wear

resistance, if the unit is expected to work for l0 years, 325 days/year and 16hoLrrs/day.

' Calculate the reactions at the supporting bearings for the input shaft andestimate its dynamic capaciry

. Present a Free Hand Sketch for the Gear Unit.tlw uv4l f_/lllL.

Pa rameter Bevel Stage Helical StasePinion Gear Pinion Gear

Module, nrni 8 8 4 4Nornral module, mm 8' 8 3.5 3.5R.P.M. I 500 750 750 300Number oIteeth l5 30 30 75Tooth width, mm 64 64 80 80MaterialUlttr"i. rt,.sq tglm#Wear stress factor, kg/mm

GG 26 GG 18 c4s sr 7026 l8 90 70

0. 10 0.10 0.1 3s 0.1 3sv.io9{L!1!!9t 0.39 0.39 0.55 0.s6

I Speed factor 1.6 1.6 1.13 t.43

Plan View

I tiltrrrat. rtt.I \1/pr'

"t.o.o

E.xaminer: Asso. Prof .l Heshum Alv Senbel

BEVEL SIAGE

LrEt lr^Al e.rAr:t=

:,,,<,Itird Year Mechanical Power I tS - June - 20011

Useful Data:

1- Helical Gear EquationsP, =oxbxrflxKP.n=o.,]rb^ffi^K,

Where, K: K,,,* K" / (K, * K1)

B*V:O.iS,[-2- Bevel Gear Equations

3- Relationst ips between the expected life of the gears and the ratio P'./ Pa

and between the dynamic load and the ratio Pa / Pt .

Pr :osb*m.*!(-bL)P.n=o.n-b^m@Where, K:K'-K.,/(e)

B,V:o.l5i6-

Pa=P,*A"cosy/(l +g;P.^,=Krrb"dp

ff=Pt*Kaxbxcos3yKr:K**Kn/cos2y

Po: P, + A r(l + B)

.go P*=Kr,.b*dp

A:P,*Ko'bKr =K*^Kn/cosd

10oooLIFE OF

loooooGEARS/HOUHS

o0 .1000

P;,6tro 2990 2roo . 3000 3500 'DYNAMTC LOAD , kg

DYNA.[llc/sr^Tlc LoAD

HELICAL STAGE

3

{{11

Zoa I

!. - -r /-U ev eL q U,f Sleq e

-

finioo.,--j.. spe.eJ r",.tio l) = 2

5.- - tir;l I 2A <A"-f - A =:';.'--C-os tp = o.gS

I-Dp*=D-Es66p = l2o- 64 sin 26.s6

= St./r -*.-D,

-- 8 x tS --. -{Zo yriyy..II

rft/ rY1 = }x9l.4x'l5oo- 6o oao

L = 4ox 32Sxl6 =

Kw. k,.. . t.-D r

o.t ^4.6 ^64,

?u = 738t. k3

LIlrorn I-d3. J.

"rf L- = szoao hr

.. ?*/fl = z.z

Pa = 62B k-s

r::LEg-z ^t

= 1.11 -/s

52ooo L,"

fGsEp

tzo /o.8?

1.

N

tt/ ttP,ot

= A.g-!3o kJ

:-

PJ= 62A kg

= 73oo

Rr." = 43oox7. l? =1.2 k,v

fp-m- | 'b"vcL I

,4€hc*^( Q"o, Stqe

X= co;'# =28.?5'Gr ttr

D;:t=

= kr.

= 6.765

4 X 3o = 12o v'','.

-7(x \2o*75o *isP,,

ft^ Bo x4zo lo.763I

I.:.'i

Pd = fi3o ks

F""* fO. Z. "tt:i 9. ln _-' rqft '=.3. 6

?t= ABa 33

.D\ o r.r.r e/ - 48Oo X

ooo ZTrY^*'Ar.. ./s

'13. kg

[t tan eo C,s tp

I torn eo S in sop

,a7u* t/*k ,t P= q.3 k,t

t,L = 52ooo hr

,:

Pa = nso l<oJ

= 48oo N

4,11 = 22.6 k,,,t

= l3o. lon zo - Gs

.6"fr2F.lr

rlr=rIa,=

_ ,\ A lz-u x />O = 4.7/6a ooo

k;. b Er lciu

= l3o.

l'lo^**t J.^^e\ f,. = H= zl x 9l -r{z = 16o b.*-

Z&=2oo {' {oe52aoo x5ox lS-.oo

loG

lA* t7}tl;* Nt/?,5rC.=4P.uoo/:-^

:RR = J

(r. *tr.6f +(tqs)t = 2o6!

I

nu=@='1

B "or;n,o

Coforitn

B eari,w /A)

?n= XPr =-2o6 kgr

C = 2o6 3,fi6so =F,a'^- .,.^^ (fr9 uql l"'1 \V

?"7=7o+zt = ?/ 4c = lt [;6s" = Fiz t4

7o ko

ke o.S F =@

@= 1o.t

F. tq5 = t.s F1

.T F

6 eor;a (fr_-_Z___:<_

xPr - 2o6 k3

q ^-,.,^^aY uql l"'' \Y

P"r= 7o+ztI

x gt.Az = 16o b.nn

Z&=2oct

r95 = I=

Ft

{: loo

Ho***.t J,r^e\ f, = H= zr

52oeo K6ox lS*ootoG

LAAn H}tl;^ nu?r - I - , rri.

t

Ru,,.r[^

o.5Fr=@

t*='@I

B ear;rt"q O.forih@-'1o''F.

1,ft

?7=

C = 2oG 3'[/r6so =

otLrtta

= k.sz h"l

f4+l