Project Diploma

8/17/2019 Project Diploma

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4.2 )irst inversion 24

4.3 -econd inversion 2

4.4 'hird inversion 2"

4.5 )ourth inversion 2%

5 /ost ana,ysis 31

i*,iogra$hy 32

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LIST OF FIGURES

figure

number

figure name

)igure 1 Machine

)igure 2 Mechanis

)igure 3 Lower $air

)igure 4 Higher $air

)igure 5 -,iding $air

)igure o,,ing $air

)igure 7 'urning $air

)igure " -crew $air

)igure % /y,indrica, $air

)igure 10 -$herica, $air

)igure 11 &oints

)igure 12 /o$,ete,y constrained otion)igure 13 -uccessfu,,y constrained otion

)igure 14 Inco$,ete,y constrained otion

)igure 15 (egree of freedo

)igure 1 (egree of freedo of various $air

)igure 17 (egree of freedo of various $air

)igure 1" )our *ar chain

)igure 1% /ran! roc!er echanis

)igure 20 (rag ,in! echanis

)igure 21 (ou*,e cran! echanis

)igure 22 (ou*,e roc!er echanis

)igure 23 ea engine echanis)igure 24 att indicator echanis

)igure 25 /ou$,ing rod of ,ocootive

)igure 2 -ing,e s,ider chain

)igure 27 eci$rocating co$ressor

)igure 2" eci$rocating engine

)igure 2% hitworth uic! return otion echanis

)igure 30 otary engine echanis

)igure 31 /ran! and s,otted ,ever echanis

)igure 32 Osci,,ating cy,inder echanis

)igure 33 Hand $u$ echanis

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CHAPTER- 1

OVERVIE

1!1INTRO"UCTION

'heory of Machines ay *e defined as that *ranch of engineering science which

dea,s with the study of re,ative otion *etween the various $arts of achine and

forces which act on the. 'he !now,edge of this su*6ect is very essentia, for an

engineer in designing the various $arts of a achine. -u* divisions of theory of

Machines 'hey 'heory of Machines ay *e su* divided into the fo,,owing four

*ranches1 #ineatics is that *ranch of theory of achines which is res$onsi*,e to study

the otion of *odies without reference to the forces which are cause this

otion i.e it8s re,ate the otion varia*,es 9dis$,aceent ve,ocity acce,eration:with the tie.

2 #inetics is that *ranch of theory of achines which is res$onsi*,e to re,ate the

action of forces on *odies to their resu,ting otion.3 (ynaics is that *ranch of theory of achines which dea,s with the forces and

their effects whi,e acting u$on the achine $arts in otion.4 -tatics is that *ranch of theory of achines which dea,s with the forces and

their effects whi,e the achine $arts are rest.

1!# HISTOR$

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• Machines and echaniss have *een devised *y $eo$,e since the dawn of

history.

• 'he ancient ;gy$tians devised $riitive achines to acco$,ish the *ui,ding of

the $yraids and other onuents. 'hough the whee, and $u,,ey 9on an aa,, huan !now,edge.>• In his ;ssai sur ,a @hi,oso$hie des -ciences he was the first to use the ter

AcineatiueB fro the Cree! word for otionD to descri*e the study of otion

without regard to forces and suggested that >this science ought to inc,ude a,,

that can *e said with res$ect to otion in its different !inds inde$endent,y of the

forces *y which it is $roduced.A

• o*ert i,,is 91"001"75: wrote the te


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'he ter echanis is a$$,ied to the co*ination of geoetrica, *odies which

constitute a achine or $art of a achine. + echanis ay therefore *e defined as a

co*ination of rigid or resistant *odies fored and connected so that they ove with

definite re,ative otions with res$ect to one another.

+ echanis is a device designed to transfor in$ut forces and oveent into adesired set of out$ut forces and the oveent. Mechaniss genera,,y consist of

oving co$onents such as gears and gear trains *e,t and chain

drives ca and fo,,ower echaniss and ,in!ages as we,, as friction devices such as

*ra!es and c,utches and structura, co$onents such as the frae fasteners *earings

s$rings ,u*ricants and sea,s as we,, as a variety of s$ecia,i=ed achine e,eents such

as s$,ines $ins and !eys.

)igure 2

#!# MACHINE

+ achine is a too, containing one or ore $arts that uses energy to $erfor an

intended action. Machines are usua,,y $owered *y echanica, cheica, thera,

or e,ectrica, eans and are often otori=ed. Historica,,y a $ower too, a,so reuired

oving $arts to c,assify as a achine. However the advent of e,ectronics has ,ed to

the deve,o$ent of $ower too,s without oving $arts that are considered achines.

+ si$,e achine is a device that si$,y transfors the direction or agnitude of a

force *ut a ,arge nu*er of ore co$,e< achines e


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#!% LIN&

Lin!s are rigid *odies each having hinged ho,es or s,ot to *e connected together

*y soe eans to constitute a echanis which a*,e to transit otion or forces

to soe another ,ocations. + ,in! is defined as a rigid *ody having two or ore $airing e,eents which connect

it to other *odies for the $ur$ose of transitting force or otion.In every achine at ,east one ,in! either occu$ies a fi


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#!2 &INEMATIC PAIR + !ineatic $air is a co*ination of two !ineatic ,in!s that have re,ative otion

with res$ect to each other.

hen two ,in!s 9or e,eents: in a achine are in contact with each other they

for a $air. hen the re,ative otion *etween these two ,in!s is co$,ete,y or $artia,,y constrained then the ,in!s are said to for a !ineatic $air.

T'(e) *f &inema+i, Pair)/

#ineatic @airs can *e *road,y c,assified into any ty$es *ased on three ain

criteria. 'he c,assification of !ineatic $airs is ,isted and descri*ed *e,ow

Ba)e0 *n +3e na+ure *f ,*n+a,+ be+4een +3e (airing eemen+)

• Lower @air

•

Higher @air Ba)e0 *n +3e +'(e *f me,3ani,a ,*n)+rain+ 5*r me,3ani,a ,*n+a,+6

• -e,f /,osed @air

• )orce /,osed @air

Ba)e0 *n +3e +'(e *f rea+i7e m*+i*n be+4een +3e eemen+) *f +3e (air

• -,iding @air

• o,,ing @air

• 'urning @air

• -crew @air 9or He,ica, @air:

• /y,indrica, @air

•

-$herica, @air

I! Ba)e0 *n +3e na+ure *f ,*n+a,+ be+4een +3e (airing eemen+)/1! L*4er Pair/

+ !ineatic $air is said to *e a ,ower $air if the ,in!s in the $air have surface or

area contact *etween the.

)igure3

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#! Hig3er Pair/ + higher $air is a !ineatic $air in which the ,in!s have $oint or ,ine contact. a,,

*earings ca and fo,,ower are e


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#! R*ing Pair/In a ro,,ing $air one e,eent undergoes ro,,ing otion with res$ect to the other.

)igure

%! Turning Pair/In a turning $air one ,in! undergoes turning otion re,ative to the other ,in!.

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9! S(3eri,a Pair/In a s$herica, $air a s$herica, ,in! turns inside a fi


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)igure11

#!9 T$PES OF CONSTRAINE" MOTION'here are 3 ty$es of constrained otion

5a6 C*m(e+e' ,*n)+raine0 m*+i*n! If the constrained otion is achieved *y the $airing e,eents these,ves then it

is ca,,ed co$,ete,y constrained otion.)igure 12

5b6 Su,,e))fu' ,*n)+raine0 m*+i*n! If constrained otion is not achieved *y the $airing

e,eents these,ves *ut *y soe other eans

then it is ca,,ed successfu,,y constrained otion.;g. )oot ste$ *earing where shaft is constrained fro oving u$wards *y its

se,f weight.)igure 11 )igure 13

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5,6 In,*m(e+e' ,*n)+raine0 m*+i*n!

hen re,ative otion *etween $airing e,eents ta!es $,ace in ore than onedirection it is ca,,ed inco$,ete,y constrained otion. ;g. -haft in a circu,ar ho,e.

)igure 14

#!< "EGREE OF FREE"OM'he nu*er of inde$endent ways *y which a dynaic syste can ove without

vio,ating any constraint i$osed on it is ca,,ed nu*er of degrees of freedo. In

other words the nu*er of degrees of freedo can *e defined as the iniunu*er of inde$endent coordinates that can s$ecify the $osition of the syste

co$,ete,y.the degree of freedo 9(O): of a echanica, syste is the nu*er of inde$endent

$araeters that define its configuration. It is the nu*er of $araeters that

deterine the state of a $hysica, syste and is i$ortant to the ana,ysis of systes

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of *odies in echanica, engineering aeronautica, engineering ro*otics and

structura, engineering.'he degree of freedo of a syste can *e viewed as the iniu nu*er of

coordinates reuired to s$ecify a configuration. +$$,ying this definition we have

• )or a sing,e $artic,e in a $,ane two coordinates define its ,ocation so it hastwo degrees of freedo

• + sing,e $artic,e in s$ace reuires three coordinates so it has three degrees

of freedo

• 'wo $artic,es in s$ace have a co*ined si< degrees of freedo

• If two $artic,es in s$ace are constrained to aintain a constant distance fro

each other such as in the case of a diatoic o,ecu,e then the si<

coordinates ust satisfy a sing,e constraint euation defined *y the distance

foru,a. 'his reduces the degree of freedo of the syste to five *ecause

the distance foru,a can *e used to so,ve for the reaining coordinate once

the other five are s$ecified.)igure 15

Rigi0 b*0' in a #"

)(a,e 3a) % "OF!

Rigi0 b*0' in a %"

)(a,e 3a) 9 "OF!

In a echanis rigid *odies ay *e constrained *y different !inds of $,anar $airs. If

n J nu*er of ,in!s 9inc,uding the frae: =1 J nu*er of ,ower $airs 9a,,owing one (O): =# J nu*er of higher $airs 9a,,owing two (O): thenm J o*i,ity of the echanis can *e deterined using the Grueber > &u+?ba,3

,ri+eri*n/

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m @ %5n-16 - #:1- :#) K 0 @re,oaded structure -u$er structure) J 0 -tructure) J 1 /onstrained Mechanis ) 1 Enconstrained Mechanis

)igure 1

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)igure 17

CHAPTER- %

FOUR BAR CHAIN

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%!1 INTRO"UTION

+ four*ar ,in!age a,so ca,,ed a four*ar is the si$,est ova*,e c,osed chain ,in!age.

It consists of four *odies ca,,ed *ars or ,in!s connected in a ,oo$ *y four 6oints.

Cenera,,y the 6oints are configured so the ,in!s ove in $ara,,e, $,anes and the

asse*,y is ca,,ed a $,anar four*ar ,in!age.

If the ,in!age has four hinged 6oints with a


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1. )our revo,ute 6oints 'he $,anar uadri,atera, ,in!age is fored *y four ,in!s and

four revo,ute 6oints denoted . It consists of two cran!s connected *y a cou$,er.

2. 'hree revo,ute 6oints and a $risatic 6oint 'he s,idercran! ,in!age is constructed

fro four ,in!s connected *y three revo,ute and one $risatic 6oint or @. It can *e

constructed with cran! and a s,ider connected *y the connecting rod. Or it can *e

constructed as a two cran!s with the s,ider acting as the cou$,er !nown as an inverted

s,idercran!.

3. 'wo revo,ute 6oints and two $risatic 6oints 'he dou*,e s,ider is a @@ ,in!age.

'his ,in!age is constructed *y connecting two s,iders with a cou$,er ,in!. If the directions

of oveent of the two s,iders are $er$endicu,ar then the tra6ectories of the $oints in

the cou$,er are e,,i$ses and the ,in!age is !nown as an e,,i$tica, trae, or

the 'rae, of +rchiedes.

@,anar four*ar ,in!ages are i$ortant echaniss found in achines.

'he !ineatics and dynaics of $,anar four*ar ,in!ages are i$ortant to$icsin echanica, engineering.

@,anar four*ar ,in!ages can *e designed to guide a wide variety of oveents.

+ssuing the frae is hori=onta, there are four $ossi*i,ities for the in$ut and out$ut

,in!s

• + cran! can rotate a fu,, 30 degrees

• + roc!er can rotate through a ,iited range of ang,es which does not inc,ude 0

or 1"0

• + 0roc!er can rotate through a ,iited range of ang,es which inc,udes 0 *ut not

1"0

• + Nroc!er can rotate through a ,iited range of ang,es which inc,udes 1"0 *ut

not 0

Crashof condition

'he Crashof condition for a four*ar ,in!age states If the su of the shortest and

,ongest ,in! of a $,anar uadri,atera, ,in!age is ,ess than or eua, to the su of thereaining two ,in!s then the shortest ,in! can rotate fu,,y with res$ect to a neigh*oring

,in!. In other words the condition is satisfied if

SL P;

where S is the shortest ,in! L is the ,ongest and P and Q are the other ,in!s.

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%!# INVERSIONS OF FOUR BAR CHAIN

Cran.-r*,.er me,3ani)m/ In this echanis either ,in! 1 or ,in! 3 is fi


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)igure 22

"*ube ,ran. me,3ani)m! 'his is one ty$e of drag ,in! echanis where ,in!s 1 3

are eua, and $ara,,e, and ,in!s 2 4 are eua, and $ara,,e,.

)igure 21

"*ube r*,.er me,3ani)m! In this echanis ,in! 4 is fi


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)igure 22

%!% APPLICATIONS

• Beam engine me,3ani)m

+ *ea engine is a ty$e of stea engine where a $ivoted overhead *ea is

used to a$$,y the force fro a vertica, $iston to a vertica, connecting rod. 'his

configuration with the engine direct,y driving a $u$ was first used *y 'hoas

Pewcoen around 1705 to reove water fro ines in /ornwa,,. 'he efficiency

of the engines was i$roved *y engineers inc,uding &aes att who added a

se$arate condenser &onathan Horn*,ower and +rthur oo,f who co$ounded

the cy,inders and i,,ia McPaught 9C,asgow: who devised a ethod of

co$ounding an e


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)igure 23

• a++ in0i,a+*r me,3ani)m

att?s ,in!age 9a,so !nown as the $ara,,e, ,in!age: is a ty$e of echanica, ,in!age

invented *y &aes att 91% &anuary 173 Q 25 +ugust 1"1%: in which the centra,

oving $oint of the ,in!age is constrained to trave, on an a$$ro


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• •

•

)igure 24

C*u(ing r*0 *f *,*m*+i7e

+ cou$,ing rod or side rod connects the driving whee,s of a ,ocootive. -tea

,ocootives in $articu,ar usua,,y have the *ut soe diese, and e,ectric

,ocootives es$ecia,,y o,der ones and shunters a,so have the. 'he cou$,ing

rods transfer the $ower to a,, the whee,s.

)igure 25

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CHAPTER 2

SINGLE SLI"ER CRAN& CHAIN

2!1 INTRO"UCTION + s,idercran! is a four*ar ,in!age that has a cran! that rotates cou$,ed to a s,ider that

the oves a,ong a straight ,ine. 'his echanis is co$osed of three i$ortant $arts

'he cran! which is the rotating disc the s,ider which s,ides inside the tu*e and the

connecting rod which 6oins the $arts together. +s the s,ider oves to the right the

connecting rod $ushes the whee, round for the first 1"0 degrees of whee, rotation.

hen the s,ider *egins to ove *ac! into the tu*e the connecting rod $u,,s the whee,

round to co$,ete the rotation.

)igure 2

2!# FIRST INVERSION

'his inversion is o*tained when ,in! 1 9ground *ody: is fi


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)igure 27

)igure 2"

2!% SECON" INVERSION

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'his inversion is o*tained when ,in! 2 9cran!: is fi


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• -crew $ress

• @owerdriven saw

• Mechanica, actuator

R*+ar' engine

'he rotary engine was an ear,y ty$e of interna,co*ustion engine usua,,y designed

with an odd nu*er of cy,inders $er row in a radia, configuration in which the

cran!shaft reained stationary in o$eration with the entire cran!case and its attached

cy,inders rotating around it as a unit. Its ain a$$,ication was in aviation a,though it

a,so saw use *efore its $riary aviation ro,e in a few ear,y otorcyc,es and

autoo*i,es.

'his ty$e of engine was wide,y used as an a,ternative to conventiona, in,ine engines

9straight or T: during or,d ar I and the years iediate,y $receding that conf,ict. It

has *een descri*ed as >a very efficient so,ution to the $ro*,es of $ower out$ut weight

and re,ia*i,ity>

)igure 30

2!2 THIR" INVERSION

'his inversion is o*tained when ,in! 3 9connecting rod: is fi


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S*++e0 ,ran. me,3ani)m

-,otted ,in! echanis gives ra the higher ve,ocity during the return stro!e 9i.e. Poncutting stro!e: .'hen the forward stro!e which reduces the wasting during the returnstro!e.

hen the *u,, whee, is rotated the cran! $in + is a,so rotated side *y side through thes,ot the cran! . 'his a!es the s,otted cran! .'his a!es the s,otted cran! toosci,,ate a*out one end /.'he osci,,ation otion of s,otted cran! a!es ra toreci$rocate. 'he interediate ( is reuired to accoodate the rise and fa,, of thecran!.

/ran! @in + decides the ,ength of the stro!es of the sha$er. 'he further it?s away frothe center of the *u,, whee, ,onger is its stro!e.

'he cutting stro!e of the ra is co$,ete whi,e cran! $in oves fro + to +1 ands,otted ,in! goes fro ,eft to right.

(uring return stro!e $in oves fro +1 to + and ,in! oves fro right to ,eft

)igure 31

O),ia+*r' engine

+n osci,,ating cy,inder stea engine 9a,so !nown as a wo**,er in the E-:Rcitation

neededS is a si$,e steaengine design that reuires no va,ve gear. Instead the

cy,inder roc!s or osci,,ates as the cran!shaft oves the $iston $ivoting in the

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ounting trunnion so that $orts in the cy,inder ,ine u$ with $orts in a fi


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cha*er o$erating in o$$osing directions. Most hand $u$s have $,ungers or

reci$rocating $istons and are $ositive dis$,aceent.

)igure 33

CHAPTER 8

COST ANAL$SIS

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BIBLIOGRAPH$

1. 'heory of Machines and Mechaniss *y &ose$h ;dward -hig,ey and &ohn &ose$h

Eic!er&r. McCrawHi,, Internationa, ;ditions.

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2. #ineatics and (ynaics of Machines *y Ceorge H.Martin. McCrawHi,,

@u*,ications.

3. Mechaniss and (ynaics of Machinery *y Hai,ton H. Ma*ie and )red . Ocvir!.

&ohn i,ey and -ons.

4. 'heory of Machines *y [email protected]. (han$at ai and /o.

5. 'he 'heory of Machines through so,ved $ro*,es *y &.-.ao. Pew age internationa,

$u*,ishers.

. + te

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