4mechanicalassembly-ch33wiley

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MECHANICALASSEMBLY

©2002 John Wiley & Sons, Inc. M. P. Goo!e,"#$n%'en(ls o) Mo%en Mn$)c($in* 2+e



MECHANICAL ASSEMBLY

-he%e% #s(enes

i!e(s n% Eyele(s

Asse'/ly Me(ho%s Bse% onIn(e)eence #i(s

(he Mechnicl #s(enin* Me(ho%s

1esi*n )o Asse'/ly



Mechnicl Asse'/ly

1ene%3se o) !io$s )s(enin* 'e(ho%s (o'echniclly ((ch (4o o 'oe 5(s(o*e(he

In 'os( cses, %isce(e h%4eco'5onen(s, clle% fasteners, e%%e% (o (he 5(s %$in* sse'/ly

In o(he cses, )s(enin* in!ol!essh5in* o esh5in* o) co'5onen(,

n% no se5(e )s(enes e e6$ie%



Po%$c(s o) Mechnicl

Asse'/ly Mny cons$'e 5o%$c(s e sse'/le%l*ely /y 'echnicl )s(enin* 'e(ho%s E7'5les8 $(o'o/iles, l*e n% s'll

55linces, (ele5hones Mny c5i(l *oo%s 5o%$c(s e

sse'/le% $sin* 'echnicl )s(enin*'e(ho%s E7'5les8 co''ecil i5lnes, ($c9s,

il4y loco'o(i!es n% cs, 'chine (ools



-4o M:o Clsses o)Mechnicl Asse'/ly

;. Me(ho%s (h( llo4 )o %issse'/ly E7'5le8 (he%e% )s(enes

2. Me(ho%s (h( ce(e 5e'nen( :oin( E7'5le8 i!e(s



esons Why MechniclAsse'/ly is )(en Pe)ee%!e (he Me(ho%s Ease of assembly < cn /e cco'5lishe%

4i(h el(i!e ese /y $ns9ille% 4o9es$sin* 'ini'$' o) s5ecil (oolin* n% in

el(i!ely sho( (i'e

Ease of disassembly < ( les( )o (he'e(ho%s (h( 5e'i( %issse'/ly So'e %issse'/ly is e6$ie% )o 'os(

5o%$c(s so 'in(ennce n% e5i cn /e5e)o'e%



-he%e% #s(enes

1isce(e h%4e co'5onen(s (h( h!ee7(enl o in(enl (he%s )o sse'/lyo) 5(s

Mos( i'5o(n( c(e*oy o) 'echniclsse'/ly

-he%e% )s(enes 5e'i( %issse'/ly

Co''on (he%e% )s(ene (y5es esce4s, /ol(s, n% n$(s



Sce4s, Bol(s, n% N$(s

Screw = e7(enlly (he%e% )s(ene *enellysse'/le% in(o blind threaded hole

Bolt = e7(enlly (he%e% )s(ene inse(e%(ho$*h holes n% >sce4e%> into a nut onthe opposite side

Nut = in(enlly (he%e% )s(ene h!in*s(n%% (he%s (h( match those on boltso) (he s'e %i'e(e, 5i(ch, n% (he% )o'



-y5icl sse'/lies 4hen sce4s n% /ol(s e $se%

Sce4s, Bol(s, n% N$(s



So'e #c(s A/o$( Sce4sn% Bol(s Sce4s n% /ol(s co'e in !ie(y o) si?es,

(he%s, n% sh5es -hee is '$ch s(n%%i?(ion in (he%e%

)s(enes, 4hich 5o'o(esin(echn*e/ili(y 3.S. is con!e(in* (o 'e(ic, )$(he

e%$cin* !i(ions

1i@eences /e(4een (he%e% )s(enes@ec( (oolin* E7'5le8 %i@een( sce4 he% s(yles n% si?es

e6$ie %i@een( sce4%i!e %esi*ns



io$s he% s(yles!il/le on sce4s n%/ol(s



-y5es o) Sce4s

Ge(e !ie(y (hn /ol(s, since)$nc(ions !y 'oe

E7'5les8 Machine screws = *eneic (y5e, *enelly

%esi*ne% )o sse'/ly in(o (55e% holes

Capscrews = s'e *eo'e(y s 'chinesce4s /$( '%e o) hi*he s(en*(h 'e(lsn% (o close (olences



Se(sce4s

H%ene% n% %esi*ne% )o sse'/ly )$nc(ions s$chs )s(enin* colls, *es, n% 5$lleys (o sh)(s

(a) Assembly of collar to shaft using a setscrew;

(b) various setscrew geometries (head types and points)



Sel)=-55in* Sce4s

1esi*ne% (o )o' o c$( (he%s in 5ee7is(in* hole in(o 4hich i( is /ein*($ne%

Also clle% tapping screw

Self tapping screws:‑

(a) thread forming,‑

and

(b) thread cutting‑



Sce4 -he% Inse(s

In(enlly (he%e% 5l$*s o 4ie coils%esi*ne% (o /e inse(e% in(o n$n(he%e% hole n% cce5( n

e7(enlly (he%e% )s(ene Asse'/le% in(o 4e9e '(eils (o

5o!i%e s(on* (he%s

35on sse'/ly o) sce4 in(o inse(,inse( /el e75n%s in(o hole (o sec$e

(he sse'/ly



Sce4 (he% inse(s8 D /e)oe inse(ion, n%

/D )(e inse(ion in(o hole n% sce4 is ($ne% in(o inse(



Wshe

H%4e co'5onen( o)(en $se% 4i(h(he%e% )s(enes (o ens$e (i*h(ness o)(he 'echnicl :oin(

Si'5les( )o' F( (hin in* o) shee( 'e(l #$nc(ions8

1is(i/$(e s(esses

Po!i%e s$55o( )o l*e clence holes

Po(ec( 5( s$)ces n% sel (he :oin(

Incese s5in* (ension

esis( in%!e(en( $n)s(enin*



Types of washers: (a) plain (flat) washers; (b) spring washers,

used to dampen vibration or compensate for wear; and (c)lockwasher designed to resist loosening of the bolt or screw



Bol( S(en*(h

-4o 'es$es8

Tensile strength, 4hich hs (he(%i(ionl %eni(ion

Proof strength = o$*hly e6$i!len( (oyiel% s(en*(h M7i'$' (ensile s(ess 4i(ho$( 5e'nen(

%e)o'(ion

-y5icl s(esses c(in* on /ol(e% :oin(



!e(i*h(enin* in Bol(e% Join(s Po(en(il 5o/le' in sse'/ly, c$sin*

s(esses (h( e7cee% s(en*(h o) )s(eneo n$(

#il$e cn occ$ in one o) (he )ollo4in*4ys8

;. S(i55in* o) e7(enl (he%s

2. S(i55in* o) in(enl (he%s

. Bol( )ils %$e (o e7cessi!e (ensile s(esses oncosssec(ionl e

-ensile )il$e is 'os( co''on 5o/le'



i!e(s

3n(he%e%, he%e% 5in $se% (o :oin (4oo 'oe 5(s /y 5ssin* 5in (ho$*hholes in 5(s n% )o'in* secon%

he% in (he 5in on (he o55osi(e si%e Wi%ely $se% )s(enes )o chie!in*

5e'nen( 'echniclly )s(ene% :oin(

Clence hole in(o 4hich i!e( isinse(e% '$s( /e close (o (he %i'e(e

o) (he i!e(



ive basic rivet types, also shown in assembled configuration: (a)

solid, (b) tubular, (c) semitubular, (d) bifurcated, and (e) compression



i!e(s < A55lic(ions n%A%!n(*es 3se% 5i'ily )o l5 :oin(s

E7'5le8 5i'y )s(enin* 'e(ho% inic)( n% eos5ce in%$s(ies

A%!n(*es8 Hi*h 5o%$c(ion (es

Si'5lici(y

1e5en%/ili(y Lo4 cos(



-oolin* n% Me(ho%s )oi!e(s;. I'5c( = 5ne$'(ic h''e %eli!es

s$ccession o) /lo4s (o $5se( (he i!e(

2. S(e%y co'5ession = i!e(in* (ool

55lies con(in$o$s s6$ee?in* 5ess$e(o $5se( (he i!e(

. Co'/in(ion o) i'5c( n% co'5ession



In(e)eence #i(s

Asse'/ly 'e(ho%s /se% on 'echniclin(e)eence /e(4een (he (4o '(in* 5(s/ein* :oine%

-he in(e)eence, ei(he %$in* sse'/ly o)(e :oinin*, hol%s (he 5(s (o*e(he

In(e)eence ( 'e(ho%s incl$%e8 Pess ((in*

Shin9 n% e75nsion (s

Sn5 (s

e(inin* in*s



Pess #i((in*

-y5icl cse is 4hee 5in e.*., s(i*h( cylin%icl 5inD o) ce(in%i'e(e is 5esse% in(o hole o)

sli*h(ly s'lle %i'e(e



Shin9 n% E75nsion #i(s

Asse'/ly o) (4o 5(s e.*., sh)( in collD (h(h!e n in(e)eence ( ( oo' (e'5e($e Shrink tting = e7(enl 5( is enl*e% /y

he(in*, n% in(enl 5( ei(he s(ys ( oo'(e'5e($e o is con(c(e% /y coolin*

Epansion tting = in(enl 5( is con(c(e% /ycoolin* n% inse(e% in(o '(in* co'5onen( =4hen ( oo' (e'5e($e, e75nsion ce(es

in(e)eence

3se% (o ( *es, 5$lleys, slee!es, n% o(heco'5onen(s on(o soli% n% hollo4 sh)(s



Sn5 #i(s

Joinin* o) (4o 5(s in 4hich '(in*ele'en(s 5ossess (e'5oyin(e)eence %$in* sse'/ly, /$(

once sse'/le% (hey in(eloc9 1$in* sse'/ly, one o /o(h 5(s

els(iclly %e)o' (o cco''o%(e(e'5oy in(e)eence

3s$lly %esi*ne% )o sli*h( in(e)eence)(e sse'/ly



e(inin* in*

#s(ene (h( sn5s in(o cic$')een(il*oo!e on sh)( o ($/e (o )o' sho$l%e

3se% (o loc(e o es(ic( 'o!e'en( o)5(s on sh)(

!etaining ring assembled into a groove on a shaft



S(i(chin*

#s(enin* o5e(ion in 4hich 3sh5e% s(i(chese )o'e% one((i'e )o' s(eel 4ie n%i''e%i(ely %i!en (ho$*h (he (4o 5(s (o

/e :oine% A55lic(ions8 shee('e(l sse'/ly, 'e(l

hin*es, '*?ine /in%in*, co$*(e% /o7es

"ommon types of wire stitches: (a) unclinched,

(b) standard loop, (c) bypass loop, and (d) flat clinch



In(e*l #s(enes

Co'5onen(s e %e)o'e% so (heyin(eloc9 s 'echniclly )s(ene%

:oin(

Me(ho%s incl$%e8 Lnce% (/s

Se'in*

Be%in*



Lnce% -/s

-o ((ch 4ies o sh)(s (o shee('e(l 5(s

lanced tabs to

attach wires or

shafts to

sheetmetal



Se'in*

E%*es o) (4o se5(e shee('e(l 5(s o(he o55osi(e e%*es o) (he s'e 5( e/en( o!e (o )o' (he )s(enin* se'

single lock seaming‑



1esi*n )o Asse'/ly 1#AD

eys (o s$ccess)$l 1#A8

;. 1esi*n (he 5o%$c( 4i(h s )e4 5(s s 5ossi/le

2. 1esi*n (he e'inin* 5(s so (hey e esy (o

sse'/le Asse'/ly cos( is %e(e'ine% l*ely in

5o%$c( %esi*n, 4hen (he n$'/e o)co'5onen(s in (he 5o%$c( n% ho4 (hey esse'/le% is %eci%e% nce (hese %ecisions e '%e, li((le cn /e

%one in 'n$)c($in* (o e%$ce sse'/ly cos(s



1#A G$i%elines

3se 'o%$li(y in 5o%$c( %esi*n Ech s$/sse'/ly sho$l% h!e '7i'$'

o) ;2 o so 5(s

1esi*n (he s$/sse'/ly o$n% /se 5((o 4hich o(he co'5onen(s e %%e%

e%$ce (he nee% )o '$l(i5leco'5onen(s (o /e hn%le% ( once



Moe 1#A G$i%elines

Li'i( (he e6$ie% %iec(ions o) ccess A%%in* ll co'5onen(s !e(iclly )o'

/o!e is (he i%el

3se hi*h 6$li(y co'5onen(s Poo 6$li(y 5(s :'s )ee%in* n%

sse'/ly 'echnis's

Mini'i?e (he%e% )s(enes 3se sn5 ( sse'/ly

4mechanicalassembly-ch33wiley

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