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QUESTION BANK

UNIT -I

TWO MARKS QUESTION AND ANSWER

1. Define Kinematic link.It is a resistive body which go to make a part of a machine having relativemotion

between them.

2. Define Kinematic pai.When two links are in contact with each other it is known as a pair. If the pair

makesconstrain motion it is known as kinematic pair.

!. Define Kinematic c"ain.

When a number of links connected in space make relative motion of any point on alink

with respect to any other point on the other link follow a definite law it is

known as kinematic chain.

#. Wite t"e $%&le'( citei)n f) *eteminin+ t"e *e+ee( )f fee*)m )f a

mec"ani(m "a,in+ plane m)ti)n.n=3(l-1-!"h-#igher pair

"oint l-

$umber of

links "-%ower pair "oint

. Define *e+ee )f fee*)m /"at i( meant &0 m)&ilit0. ApMa0-23345&he mobility of a mechanism is defined as the number of input parameters which must beindependently controlled in order to bring the device into a particular position.

6. Wite t"e K%t7&ac"'( elati)n. ApMa0-23345'utbach)s criterion for determining the number of degrees of freedom or movability(n

of a plane mechanism is n=3(l-

1-!"-h n-*egree of freedom.l-$umber of

links. h-#igher pair

"oint "-%ower

pair "oint.



8. Define $a(")ff'( la/ an* (tate it( (i+nificance. ApMa0-23345It states that in a planar four bar mechanism+ the sum of shortest link lengthand

longest link length is not greater than the sum of remaining two links length+ if there is

to be continuous relative motion between two members.,ignificance

rashoff)s law specifies the order in which the links are connected in a kinematic

chain. rashoff)s law specifies which link of the four-bar chain is fi/ed.(s01=(p0 should be

satisfied+ if not+ no link will make a complete revolution relative to

another. s= length of the shorter lengthl= length of the longest link

p 2 are the lengths of the other two links.

4. Define In,e(i)n )f mec"ani(m.&he method of obtaining different mechanism by fi/ing different links in a kinematic

chainis known as inversion of mechanism.

9. W"at i( meant &0 Mec"anical a*,anta+e )f mec"ani(m:It is defined as the ratio of output torue to the input torue also defined as the ratioof

load to effort.

.4 ideal = &5 6 &4

&5 =driven (resistingtorue &4 =driving

torue

13. Define Tan(mi((i)n an+le.&he acute angle between follower and coupler is known as transmission angle.

11. Define T)++le p)(iti)n.If the driver and coupler lie in the same straight line at this point mechanicaladvantage is

ma/imum. 7nder this condition the mechanism is known as toggle position.

12. ;i(t )%t fe/ t0pe( )f )ckin+ mec"ani(m.8endulum motion is called rocking mechanism.1. 9uick return motion mechanism.

!. :rank and rocker mechanism.3. :am and follower mechanism.

1!. Define pant)+ap".It is device which is used to reproduce a displacement e/actly in a enlarged scale. Itis

used in drawing offices+ for duplicating the drawing maps+ plans+ etc. It workson the principle of ; bar chain mechanism.



<g. scillating-scillating converter mechanism

1#. Name t"e applicati)n )f cank an* (l)tte* le,e <%ick et%n m)ti)n mec"ani(m.1. ,haping machines.!. ,lotting mechanism.

3. >otary internal combustion engine.

1. Define (t%ct%e.It is an assemblage of a number of resistant bodies having no relative motion between

them and meant for carrying loads having straining action.

16. W"at i( (imple mec"ani(m:4 mechanism with four links is known as simple mechanism.

18. Define mec"ani(m.When one of the links of a kinematic chain is fi/ed+ the chain is known as a

mechanism.

14. Define e<%i,alent mec"ani(m= an* (patial mec"ani(m.<uivalent mechanism &he mechanism+ that obtained has the same number of thedegree

of freedom+ as the original mechanism called euivalent mechanism.,patial mechanism ,patial mechanism have special geometric characteristics in that

all revolute a/es are parallel and perpendicular to the plane of motion and all prisma/es lie in the plane of motion.

19. Define *)%&le (li*e cank c"ain mec"ani(m.4 kinematic chain which consists of two turning pair and two sliding pair is known

asdouble slider crank mechanism.

23. Define (in+le (li*e cank c"ain mec"ani(m.4 single slider crank chain is a modification of the basic four bar chain. It consists of one

sliding pair and three turning pair.

4pplications>otary or nome engines :rank and slotted lever mechanism

scillating cylinder engine 5all engine

#and pump

21. Define Sli*in+ pai.In a sliding pair minimum number of degree of freedom is only one.

22. Define T%nin+ pai.In a turning pair also degree of freedom is one. When two links are connected suchthat

one link revolves around another link it forms a turning pair.



2!. Define c0lin*ical pai.In a cylindrical pair degree of freedom is two. If one link turns and slides alonganother

link it forms a cylindrical pair.

2#. Define R)llin+ pai.In a rolling pair degree of freedom is two. &he ob"ect moves both linearlyand angularly.

2. Define Sp"eical pai.In a spherical pair degree of freedom is three. It can both move left and right+upand

down+ and rotate along the same point.

26. Define ;)/e pai.If contact between two links is surface contact also having degree of freedom one+

thenthe pair is known as lower pair.

</ample ,liding pair.

28. Define "i+"e pai.If contact between two links is either point contact or line contact then the pair isknown

as higher pair.

</ample 8oint contact->olling pair.%ine contact-:ylindrical

pair.

>ART-B 16 Mak(5

1. a </plain different types of%ink.45

b:lassifyand e/plain the 'inematicpair.45

!. a </plain anytwo inversion of four bar chain.45

b</plain the first inversion of,ingle ,lider:rank :hain.45

3. a </plain first inversion of*ouble,lider crank chain.45

b</plain third inversion of double slider crank chain.45

;. a </plain the offset slider crank mechanism.45

b</plain ,traight line mechanismwith neat sketch45

?. aWith the help of aneat sketch e/plain the workingof ldham@s coupling. 45

b</plain steering gearmechanismwith neat sketch 45



UNIT -II

A. With the help of aneatsketch e/plain the workingof Whitworth

uick return mechanism. (1A

B. With the help of aneatsketch e/plain the workingof ,ingle

slider and double slider crankchain mechanism.165


1. W"at ae t"e c)mp)nent( )f acceleati)n:>adial component of acceleration&angential component of acceleration

2. Wite an e?pe((i)n f) fin* n%m&e )f in(tantane)%( cente( in a mec"ani(m. $=n(n-16!+ n-no of links

!. W"at i( e?pe((i)n f) @)i)li( c)mp)nenet )f acceleati)n:

a 5:

=!r ω

Where ω=4ngular velocity of

@4) C=%inear

velocity of @5)

#. )/ can /e epe(ent t"e *iecti)n )f linea ,el)cit0 )f an0 p)int )n a link /it"

e(pect t) an)t"e p)int )n t"e (ame link:&he direction of linear velocity of any point on a link with respect to another point on

thesame link the direction is perpendicular to the line "oining the points.

. W"at i( t"e e?pe((i)n f) a*ial an* tan+ential c)mp)nent )f acceleati)n:>adial component

4rc5=ω5D5&angentialcomponent

4rc 5=α5D5

Where ω5=4ngular velocity of link 5α5=4ngular acceleration oflink 5 5=%ength of link 5.

(>adial component of acceleration is perpendicular to the velocity of thecomponent andtangential component is perpendicular to link position

6. Define in(tantane)%( cente an* in(tantane)%( a?i(:



Instantaneous center of a moving body may be defined as that center which

goes on changing from one instant to another.

Instantaneous a/is is a line drawn through an instantaneous center and

perpendicular to the plane of motion.

8. W"at ae t"e name( )f in(tantane)%( cente:Cirtual center :entro>otopole.

4. )/ can /e appl0 in(tantane)%( cente met")* t) *etemine ,el)cit0::onsider three points 4+ 5+ : on a rigid link. I am being instantaneous :enter. %etC4+

C5+ C: be the points 4+ 52 :. &hen we have

C46I4=C56I5=C:6I:

9. W"at i( t"e )&ecti,e )f Kinematic anal0(i(:&he ob"ective of 'inematic analysis is to determine the 'inematic uantities such

asdisplacement+ velocity and acceleration of the element in a mechanism.

13. Wite an0 t/) %le( t) l)cate In(tantane)%( cente.When two links are connected by a pin "oint the instantaneous center lies on the center of

the pin.When two links have a sliding contact+ the instantaneous center lies at infinity

in a direction perpendicular to the path of motion of slide.

11. Define Kenne*0'( t"e)em.&he 'ennedy)s theorem states that if three bodies move relatively to each other+they

have three instantaneous centers and lie on a straight line.

12. W"at i( meant &0 efficienc0 )f a mec"ani(m:<fficiency of a mechanism is defined as the ratio of the product of force and velocityin



driven link to the product of force and velocity in driving link.

1!. A pin )in( t/) link( A C B. A )tate( /it" ωA an+%la ,el)cit0 an* B )tate( /it"

ωB

an+%la ,el)cit0 in )pp)(ite *iecti)n. W"at i( t"e %&&in+ ,el)cit0 )f t"at p)int:

>ubbing velocity of pin = ( ω4 0 ω5 D r Where @r) is the radius of pin.

1#. W"at i( t"e ma+nit%*e )f linea ,el)cit0 )f a p)int B )n a link AB elati,e t) A:

&he magnitude of linear velocity of a point 5 on a link 45+ which rotates with

@ ω)angular velocity with respect to 4 is

C564 =ω 465 D45

>ART-B 16 Mak(5

1. &he:rank ofaslider crank mechanisms rotatesclockwise at a :onstant speed

of

AEE r.p.m. &he crank is 1!? mmand connectingrodis ?EE mmlong.

*etermine1. %inear velocityand acceleration ofthe mid 8ointof the

connecting rod+ and !. 4ngular velocityandangular acceleration ofthe

connecting rod+ at acrankangle

of;?F from innerdead centreposition.

!.Ina four link mechanism+ thedimensions of thelinks are45=!EE mm+

5:=;EEmm+ :*=;?E mm and 4*=AEEmm. 4t the instant when *45=GEF+

the link 45hasangularvelocityof3A rad6s in the clockwisedirection.

*etermine (i &he velocityof point:+ (ii &hevelocityof point<onthe link 5:

When 5< =!EE mm (iii the angularvelocities oflinks 5: and :*+

ivacceleration oflink oflink 5:

3. &hedimensions of thevarious links of amechanism+ as shown in fig. are

as follows 4=3EE mmH 45=1!EEH5:=;?E mmand :*=;?E mm. ifthe

crank 4 rotates at !E r.p.m. in theanticlockwise direction and gives

motion to the sliding blocks 5and *+find+ forgivenconfiguration

(1Celocityof slidingat5and *+ (! 4ngular velocityof :*

(3%inearacceleration of* and (;angularacceleration of :*.

; a*erivethe e/pressions forCelocityandacceleration ofpiston in



reciprocating steam engine mechanismwith neat sketch

b.*erivethe e/pression for :oriolis component of acceleration with neatsketch

?.Inaslider crankmechanism+ the length of thecrank and theconnectingrod

are1EE mmand ;EE mmrespectively.6 &hecrank position is ;?F fromI*:+

the crank shaft speed is AEE r.p.m. clockwise.7sing analytical method

*etermine

(1Celocityandacceleration of theslider+and (!4ngular

velocityandangular acceleration oftheconnectingrod.

A.%ocate allinstantaneous centers of theslider crank mechanismH thelength of

crank

5and :onnecting rod 45are1!? mmand ?EE mm respectively. &hecrank speed is AEErpm clockwise. When thecrank has turned ;?F from theI*:. *etermine(ivelocityof

. slider@4@ (ii4ngular Celocityofconnecting rod J 45@.

UNIT -III


1. W"at i( a cam: $i,e ()me e?ample(:4 :am is a rotating machine element+ which gives reciprocating or oscillating motionto

another element known as

follower. </amples are>adial or *isc+ :ylindrical or 5arrel+ <nd or Kace cams and Wedge cams.

2. W"at i( t"e @la((ificati)n )f cam(:

• 4ccording to cam shape

• 4ccording to follower movement

• 4ccording to manner of constraint of the follower

!. @la((if0 cam( &a(e* )n t"ei ("ape.

• Wedge cam • >adial cams • ,piral cams

• *rum cams • ,pherical cams

#. W"at i( t"e cla((ificati)n )f f)ll)/e(:(i 4ccording to follower shape(ii 4ccording to motion of follower

. W"at i( a )lle f)ll)/e:In place of a knife edge roller is provided at the contacting end of the follower

6. W"at i( a Sp"eical f)ll)/e:In the contacting end of the follower is of spherical shape.



8. W"at i( meant &0 an+le )f a(cen*:&he angle of rotation of the cam from the position when the follower begins to risetill it

reaches its highest points. It is denoted by L

4. W"at i( meant &0 an+le )f *e(cen*:&he angle through which the cam rotates during the time the follower returns to theinitial

position. It is denoted by Lr.

9. W"at i( an+le )f */ell:It is the angle through which the cam rotates while the follower remains stationary atthe

highest or the lowest.

13. W"at i( meant &0 an+le )f acti)n:

&he total angle moved by the cam during its rotation between the beginning of

rise and the end of return of the follower.

11. W"at i( a*ial ) *i(c cam(:In radial cams the follower reciprocates or oscillates in a direction perpendicular tothe

cam a/is. &he cams are all radial rams. In actual practice+ radial cams are widely

used due to their simplicity and compactness.

12. W"at i( */ell:&he ero displacement or the absence of motion of the follower during the motion ofthe

cam is called dwell.

1!. W"at ae t"e cla((ificati)n( )f f)ll)/e acc)*in+ t) f)ll)/e ("ape:

• 'nife edge follower

• >oller follower

• ushroom or flat faced follower and

• ,pherical faced or curved shoe follower

1#. W"at ae t"e cla((ificati)n( )f f)ll)/e acc)*in+ t) t"e m)ti)n )f t"e f)ll)/e:

• >eciprocating or translating follower

• scillating or rotating follower

1. W"at ae t"e cla((ificati)n( )f f)ll)/e( acc)*in+ t) t"e pat" )f m)ti)n:

• >adial follower • ffset follower

16. W"at i( t"e m)ti)n )f t"e f)ll)/e:&he follower can have any of the following four types of motions

• 7niform velocity • ,imple harmonic motion



• 7niform acceleration and retardation • :ycloidal motion.

18. W"at i( t"e applicati)n )f cam::losing and opening of inlet and e/it valve operating in I: engine .

14. W"at ae t"e nece((a0 element( )f a cam mec"ani(m::am-&he driving member is known as the camKollower-&he driven member is known as the

follower. Krame-It supports the cam and guider

the follower.

19. W"ee ae t"e )lle f)ll)/e e?ten(i,el0 %(e*: ApMa0-23345>oller followers are e/tensively used where more space is available such as instationary

gas oil engines and aircraft

engines.

23. Wite t"e f)m%la f) ma?im%m ,el)cit0.Co (ma/ =!Ms

Lo

Cr (ma/ =

!Ms

>ART-B 16 Mak(5

1.4 cam is to give the followingmotion to aknifeedgedfollower

(a utstrokeduringAEFof cam rotation

(b*wellfor thene/t ;?F of cam rotation

(c >eturn strokeduring ne/t GEF of cam rotation and

(d*wellfor theremainingofcam rotation

&hestrokeof thefollower is ;E mmand the minimumradius of the cam is?E mm.

&he followermoves with uniform velocityduringboth theoutstrokeand return

strokes.*raw the profileof thecam when (a thea/is of the follower passes

through thea/is of the cam shaft+ and (bthe a/is of the follower is offset

by!Emmfrom the a/is of the cam shaft.

!. *raw theprofileofacam operatinga'nife-edgedfollower from the following data

(aKollower to moveoutward through ;E mm duringAEF ofa cam rotationH(b

Kollower to dwellforthene/t ;?F (c Kollowertoreturn its original position during

ne/t GEF (dKollower to dwellforthe rest of camrotation. &hedisplacement of the



follower is to takeplacewith simple harmonic motion duringboth theoutward and

return strokes. &heleast radius of the cam is ?Emm.If the cam rotates at 3EE r.p.m.+

determinethe ma/imum velocityand accelerationof the follower duringtheoutward

stroke and return stroke.

3. 4 cam+ with aminimum radius of ?E mm+ rotatingclockwise at a uniform speed+

is reuired togiveraknife-edgedfollower themotion as described below (a &o

moveoutwards through ;E mmduring1EEF rotation of the camH (bto dwellforne/t

NEF (c &o return to its startingposition duringne/t GE F and (d&odwellforthe rest

periodof revolution. *raw theprofileof the cam (i When thelineof strokeof the

follower passes through the centreof the cam shaft and (iiWhen the line ofstrokeof

the follower is to takeplacewith 7niform acceleration and uniform retardation.

*eterminethe ma/imum velocity and acceleration of the followerwhen the cam

shaft rotates at GEE r.p.m.

;. *raw theprofileofacam operatingaroller reciprocatingfollowerand with the

followingdata

inimum radius of cam =!? mmHlift=3EmmH >ollerdiameter=1?mm. &hecam lifts

the follower for 1!EF with ,#+ followed byadwellperiod of3EF. &henthe follower

lowers down during1?EFof cam rotation with uniform acceleration and retardation

followed byadwellperiod.If thecam rotates atauniform speed of 1?E >8.

:alculate the ma/imumvelocityand accelerationof follower duringthe descent

period.

?.It is reuired to set outthe profileof a cam togivethe followingmotion to the

reciprocating follower with a flat mushroom contact surface (iKollower to

haveastrokeof !Emm during1!EF ofcam rotation+ (ii Kollower to dwellfor3EF

ofcam rotation+(iii Kollower to return to its initial position during1!EF of cam

rotation+ (ivKollower to dwellfor remainingGEFof cam rotation. &heminimum

radius of the cam is !? mm. &heout strokeof the follower is performed with

,# and return strokewith eual uniform acceleration andretardation.

A. 4 tangent cam to drivea roller follower throughatotal lift of 1!.? mm fora cam

rotation ofB?F.&hecam speed is AEErpm . &hedistancebetweencam centre and



follower centre atfull lift is ;? mm and the roller is !E mmin diameter. Kind the

cam proportions and plot displacement+ velocityandacceleration for one full cycle.

UNIT -I


1. Define (p% +ea.4 spur gear is a cylindrical gear whose tooth traces are straight line generation of the

reference cylinder. &hey are used to transmit rotary motion between parallel shafts.

2. Define a**en*%m an* *e*en*%m.4ddendum is the radial distance of a tooth from the pitch circle to the top of the tooth.*edendum is the radial distance of a tooth from the pitch circle to the bottom of thetooth.

!. Define cic%la pitc".

It is the distance measured on the circumference of the pitch circle from a point ofone

tooth to the corresponding point on the ne/t tooth. It is denoted by 8c

:ircular pitch 8c= Π6*&

Where * = *iameter of pitch

circle. & = $umber of teeth on

the wheel.

#. Define I5 pat" )f c)ntact. II5 ;en+t" )f pat" )f c)ntact.8ath of contact It is the path traced by the point of contact of two teeth fromthe

beginning to the end of engagement.

%ength of path of contact It is the length of common normal cut- off by theaddendum circles of the wheel and pinion.

. State t"e la/ )f +eain+.%aw of gearing states that+ the common normal at the point of contact between a pairof

teeth must always pass through the pitch point.

6. Define c)n%+ate acti)n.When the tooth profiles are so shaped so as to produce a constant angular velocityratio

during eshing+ then the surface are said to de con"ugate.

8. Define an+le )f app)ac".&he angle of approach is defined as the angle through which a gear rotates fromthe

instant a pair of teeth comes into contact until the teeth are in contact at the pitch point.



4. ;i(t )%t t"e c"aactei(tic( )f in ,)l%te acti)n.a 4rc of contact. b %ength of path of contact. c :ontact ratio.

9. Define c)ntact ati).:ontact ratio is defined as the ratio of the length of arc of contact to the circular pitch.athematically.:ontact ratio = length of arc of conta

8cO Where 8c = circular path.

13. W"at i( t"e a*,anta+e )f in,)l%te +ea:&he most important advantage of involutes gear is that the center distance for a

pair of involute gears can be varied within limits without changing the velocity ratio.

11. W"at ae t"e c)n*iti)n( t) &e (ati(fie* f) intec"an+ea&ilit0 )f all +ea(:Kor interchangeability of all gears+ the set must have the same circular pitch+

module+diameter pitch+ pressure+ angle+ addendum and dedendum and tooth thickness must

be one half of the circular pitch.

12. Define +ea t))t" (0(tem.

4 tooth system is a standard which specifies the relationship between addendum+

dedendum+ working depth+ tooth thickness and pressure angle to attain

interchangeability of gears of tooth numbers but of the same pressure angle and pitch

1!. Define c0cl)i*.4 cycloid is the curve traced by a point on the circumference of a circle whichrolls

without slipping on a fi/ed straight line.

1#. Define cleaance.&he amount by which the dedendum of a gear e/ceeds the addendum of the matinggear

is called clearance.

1. W"en in ,)l%te intefeence )cc%(.If the teeth are of such proportion that the beginning of contact occurs beforethe

interference point is met then the involute proportion of the driven gear will mate a

non in volute portion of the driving gear and involute interference is said to occur.16. W"at i( t"e pinciple ea()n f) empl)0in+ n)n (tan*a* +ea(:

a &o eliminate the undercutting. b &o prevent interference.c &o maintain reasonable contact ratio.



18. W"at ae t"e a*,anta+e( an* *i(a*,anta+e( )f +ea *i,e:4dvantages

a It transmits e/act velocity

ratio. b It has high

efficiency.

*isadvantages&he manufacture of gears reuire special tool and euipment.

&he error in cutting teeth may cause vibrations and noise during operation.

14. Define "eli? an+le β5.

It is the angle between the line drawn through one of the teeth and the center line of the

shaft on which the gear is maintained.

19. Define +ea ati).&he uotient of the number of teeth on the wheel divided by the number of threads onthe

worm.

23. Define +ea tain.4 combination of gears that is used for transmitting motion from one shaft toanother

shaft is known as gear

train. eg. spur gear+

spiral gear.

21. Define ,el)cit0 ati).Celocity ratio of a simple gear train is defined as the ratio of the angular velocity of

thefirst gear in the train to the angular velocity of the last gear.

>ART-B 16 Mak(5

1. a &wo matingspurgear with modulepitch of A.? mmhave1G ad ;B teeth of

!EF pressureangle and A.? mm addendum. *eterminethe number ofpair of

teethand angleturned through bythelarger wheel foronepair ofteeth in contact.

*eterminealso theslidingvelocityat theinstant (iengagement commences (ii

engagement terminates. When the pitch line velocityis 1.! m6s.45

b&henumberof teeth on each of thetwo spurgears in mesh is ;E. &heteeth have

!EF involuteprofile and the module isAmm.If thearcof contact is 1.B? times the circularpitch.

Kind theaddendum. 45



2. a &wo !EF involutespurgears haveamoduleof 1E mm. &he addendumis one

module. &helargergear has ?E teeth and pinion 13 teeth. *oes the

interferenceoccurPIfitoccurs+ to whatvalue should thepressureanglebe changed

to eliminate interferenceP45

b&womatinginvolute spur gears !EF pressure angle haveagearratio of!.the

numberof teeth on thepinion is !E and its speed is !?E rpm. &hemodulepitch of the

teeth is 1! mm. if theaddendum on each wheelwheel recess on each side arehalf

thema/imum possible lengtheach+ find(1the addendum forpinion and

gearwheel(!the length of arcof contact(3E thema/imum velocityof

slidingduringapproachand recess.4ssume pinion to bedriver . 45

!.a 4pair of spurgearwith involuteteeth is to give agear ratio of ;1. &he arcof

approach is not be less than the circular pitch and thesmaller wheel is the driver. &he

angleof pressureis 1;.?What is the least number ofteeth can beusedoneach wheelP

What is the addendum of thewheel in terms ofcircularpitchP45

b. 4 pair !EF fulldepth involutespur gear having 3E and ?E teeth

respectively module; mmarcin mesh+ thesmaller gearrotates at 1EEE rpm.

*etermine (a ,lidingvelocities at engagementand disengagement of apair

ofteethand (b :ontact ratio.45

!.Inan epicyclicgear train theinternal wheels 4and 5and compound wheels

:and

* rotateindependentlyabout a/is . &hewheels < andKrotateon pins fi/ed to the arm . <

gears with4 and : . Wheel Kgearwith 5 and *. 4llthe wheels havethe same

module and the numberof teeth are &:=!N &*=!AH&<=&K=1N.(1 ,ketch the

arrangement+ (! Kind thenumber ofteeth on 4 and 5+(3Ifthe arm makes 1EE

rpm clockwise and 4 is fi/ed+ find thespeed of5+ and (;If thearm makes 1EE

rpm clockwise and wheel 4 makes 1Erpm counter clockwiseH Kind

the speed ofwheel5. 165

#. &wogearwheels meshe/ternallyandaretogiveavelocityratio of 3to 1. &he

teeth areof involute formHmodule=Amm+ addendum=onemodule+

pressureangle=!EF. &he pinion rotates at GE rpm. *etermine (1 thenumber

ofteeth on thepinion toavoid interferenceon itand the correspondingnumber

SCE 104Department of Mechanical

Engineeri

ng



ofteeth on thewheel+ (!&helength of path andarc of contact+ (3the numberof

pairs of teeth in contact.165

. &he arm ofan epicyclicgear train rotatesat 1EErpm in the anticlock wisedirection.

&he arm carries two wheels 4and5having3A and ;? teeth respectively. &hewheel 4is fi/ed and the arm rotates about thecentreof wheel 4. Kind thespeed of wheel5.

What will be the speed of5+ if thewheel4 instead of beingfi/ed+ makes !EE rpm

(clockwise.165

6.Ina revertedepicyclictrain+ the armK carries two wheels 4and * anda compound

wheel 5-:. Wheel 4 meshes with wheel5and Wheel * meshes with wheel :. &her

numberof teeth on wheel 4+ *and : areNE+;N+ and B!. Kind thespeed and direction

ofwheel * + when wheel 4 is fi/ed and arm Kmakes !EE rpm clockwise.165

8. 4n epicyclictrain is composed of afi/ed annularwheel 4 having1?E teeth. eshingwith 4 isawheel 5which drives wheel * throughan idlewheel :+ * being concentricwith 4. Wheels 5 and

: are carried onarm which revolves clockwise at 1EE rpm about the a/is of 4 or*.Ifthe wheels

5and * arehaving!? teeth and ;E teeth respectively+find thenumberof teeth of : and the speedand sense ofrotation of :. 165

4. &hesun planetgear ofan epicyclicgear train+ the annular* has 1EE internal teeth+

the sun gear 4has ?E e/ternal teethand planetgear 5has !?e/ternal teeth.&hegear

5meshes withgear *and gear 4. &hegear5is carried onarm <+ which rotatesabout

the centreof annulargear*.If thegear *is fi/edand arm rotates at !E rpm+ then find

the speeds ofgear 4and5.165

UNIT -


1. Define cl%tc".:lutch is a transmission device of an automobile which is used to engage anddisengage

the power from the engine to the rest of the system.

2. W"at ae t"e t0pe( )f ficti)ncl%tc"e(:

&ypes of friction clutchesare

D*isc or plate clutches.

D:one clutches.

D:entrifugal clutches.



!. Define centif%+al cl%tc".:entrifugal clutch is being increasingly used in automobile and machinesobviously it

works on the principle of centrifugal force.

#. W"at ae t"e t0pe( )f flat *i,e(:&he types of flat drives areD:ompound belt drive.

D,tepped or cone pulley drive.

DKast and loose pulley.

. Define (lip.,lip is defined as the relative motion between the belt and pulley.

6. Define la/ )f &eltin+.%aw of belting states that the centre line of the belt+ as it approaches the pulley liein a

plane perpendicular to the a/is of that pulley or must lie in the plane of the pulley+otherwise the belt will run off the pulley.

8. W"at i( t"e %(e )f )pe *i,e:&he rope drives are widely used when large power is to be transmitted continuouslyfrom

one pulley to another over a considerable distance. ne advantage of rope drives isthat a number of separate driver may be from the driving pulley.

4. W"at i( t"e %(e )f &elt *i,e:5elt drive is commonly used for transmission of power when e/act velocity ratio is

notreuired. enerally+ belt drives are used to transmit power from one pulley to another+

when the two pulleys are not more than 1E meters apart.

9. W"at ae t"e t0pe( )f )pe(:&he types of ropes are DKiber ropes. DWire ropes.

13. W"at i( t"e %(e )f <%ate t%n left *i,e:&he uarter turn left drive is used with shafts arranged at right angles and rotating inone

definite direction.

11. Define t"e ,el)cit0 ati) )f t"e &elt *i,e.&he velocity ratio of the belt drive is defined as the ratio between the velocities ofthe

driver and the follower or the driven.



12. W"at ae t"e a*,anta+e( )f D-&elt:D8ower transmitted is more due to wedging action in the grooved pulleys.DC-belt is more compact+ uite and shock absorbing.

D&he C-belt drive is positive because of negligible slip between the belt and the groove.

D#igh velocity ratio may be obtained.

1!. W"at ae t"e *i(a*,anta+e( )f D-&elt:

DIt cannot be used with large center distances.DIt is not as durable as flat belt.

DIt is a costlier system.

1#. W"at i( t"e %(e )f cic%la &elt( )

)pe(:D>opes are circular in cross section.DIt is used to transmit more power.

D*istance between two pulleys is more than Nmetres.

1. Specif0 t"e ,ai)%( &elt mateial(.5<%& &Q8<, 5<%& 4&<>I4%,

Klat belts %eather+ canvas+ cotton 2 rubber.

C-belts >ubberied fabric 2 rubber.

>opes :otton+ hemp 2 manila.

16. Name t"e t0pe( )f ficti)n.D,tatic friction. D*ynamic friction.

18. Define t"e an+le )f ep)(e.If the angle of inclination @R) of the plane to horiontal is such that the body begin

tomove down the plane. &hen the angle R is called the angle of repose.

14. W"at i( meant &0 ficti)nal f)ce:Korce of friction is always acting in the direction opposite to the direction of motion.

19. W"0 (elf l)ckin+ (ce/( "a,e le((e efficienc0:,elf locking needs some friction on the thread surface of the screw and hence itneeds

higher effort to lift a body and hence automatically the efficiency decreases.

23. W"at i( (tatic ficti)n:It is the friction e/perienced by a body+ when at rest.

21. W"at i( *0namic ficti)n:It is the friction e/perienced by the body+ when in motion. &he dynamic friction isalso

called as kinematic friction.



22. W"at i( c)-efficient )f ficti)n:It is defined as the ratio of the limiting friction (K to the normal reaction (>$ between

the two bodies. It is generally denoted by S. S=K6>$.

2!. Define (ce/ ack.&he screw "ack is the device used to lift the heavy loads by applying acomparatively

small effort at its handle. &he working principle of screw "ack is similar to that of an

inclined plane.

>at B1. a Kor a flat belt+ prove that &16&!=eST Where &1 and &!= &ension in the tight

and slack sides of the belt+ T= 4ngle of contact between the belt and the pulley+

and S= :oefficient of friction between the belt and the pulley. 45

b 4n open belt running over two pulley of 1.? m and 1.E m diameters connectstwo parallel shafts ;.N m apart. &he initial ten in the belt is 3EEE $. &he smaller

pulley is rotating at AEE rpm. &he mass of belt is E.ABE3 kg6m length. &he

coefficient of friction between the belt and pulleys is E.3. Kind (1 the e/act length

of the belt reuired (! the power transmitted taking c.f tension into account. 45

!.a 4 multiplate disc clutch transmits ?? 'W of power at 1NEE rpm. :oefficient of

friction for the friction surfaces is E.1. 4/ial intensity at pressure is not to e/ceed

1AE

'$6m!. &he internal radius is NE mm and is E.B times the e/ternal radius. Kind

the number of plates needed to transmit the reuired torue 45

b 4 rope drive is reuired to transmit !3E 'W from a pulley of 1m diameter

running at ;?E rpm. &he safe pull in each rope is NEE $ and the mass of the rope isE.; kg per meter length. &he angle of lap and groove angle 1AEE and ;?E

respectively. If coefficient of friction is E.3+ find the number of ropes reuired. 45

3.&he mean diameter of the screw "ack having pitch of 1E mm is ?E mm. 4 load of !E

'$ is lifted through a distance of 1BE mm. Kind the work done in lifting the load

and efficiency of the screw "ack when (i the load rotates with the screw+ and (ii theload rests on the loose head which does not rotate with screw. &he e/ternal and

internal diameter of the bearing surface of the loose head is AE mm and 1Emm

respectively. &he coefficient of friction for the screw as well as the bearing surface

may be taken as



E.EN. 165

;.a.4 leather belt is reuired to transmit B.? kw from a pulley 1.! m in

diameter+ running at !?E rpm. &he angle entranced is 1A? E and the coefficient

of friction

between the beltA and the pulley is E.3. If safe working stress for the leather belt is 1.?

8a+ density of leather is 1 kg6 m3 end thickness of belt is 1E mm. *etermine

the width of the belt taking :.K tension into account. 45

b.&wo pulley one ;?E mm diameter and other !EEmm dia are on parallel shaft !.1

m apart and are connected by a cross belt. &he larger pulley rotates at !!? rpm.

&he ma/imum permissible tension in the belt is 1 '$ and the coefficient of friction

between the belt and the pulley is E.!?. Kind the length of the belt reuired and the

power can be transmitted. 45

?.&wo shaft whose centers are 1m apart are connected by a C belt drive. &he

driving pulley is supplied with 1EE 'W and has an effective diameter of 3EE mm.

It runs at 3B? rpm. &he angle of groove on the pulley is ;E E &he permissible

tension in ;EE mm! cross sectional area of the belt is !.1 8a. &he density of the

belt is 11EE kg6 mm3 coefficient of friction is E.!N. <stimate number of belts

reuired. 165

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