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TERM PAPER
KINEMATICS OF MACHINE
MEC 202
TOPIC: Study the cam prof!e" u"ed # ma#ufactur#$ mach#e"
Date of allotment: 14/10/2010
Date of Submission: 15/11/2010
Submitted to: Submitted by:
Mr. Kamlesh Mishra Name: Sachin ana
!De"tt. #f Mechanical$ e%. No: 10&04&'(
Section: K4&01
oll No: K 4&01 )*5
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ACKNO%&E'(EMENT
+o many indi,iduals - am indebted %ood counsel and assistance in
,arious ays in this res"ect one of my sincerest thans toMr. Kamlesh
Sir of o,ely rofessional 3ni,ersity ha%ara for their ind
coo"eration and able %uidance.
- oe a dee" sense of ine"tness of my "ureness that has been source of
ins"iration in e,ery or of my life.
- dee"ly e"ress our ine"tness and thans to all my faculty member and
friends for there in ,aluable %uidance hich enable me to brin% out this
"roect in a "resentable manner.
Sachin
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A)STRACT
+he term "a"er "resents the analysis of ,arious cam "rofiles used in
manufacturin% machines. -t focuses mainly on the ty"es of cam and its
folloers and ho are they classified accordin% to their sha"e manner
of mo,ement and motion. -t also focuses on the %ra"hical re"resentation
of the cam "rofile i.e. ho are they constructed and hat are the
"rocedure to construct a cam "rofile and ho they can be used in a
machine.
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INTRO'*CTION
6 cam is a mechanical member used to
im"art desired motion to a folloer by direct
contact. 6 cam is a rotatin% or slidin% "iece
in a mechanical lina%e used es"ecially in
transformin% rotary motion into linear
motion or ,ice7,ersa. +he cam may be
rotatin% or reci"rocatin% hereas the
folloers may be rotatin% reci"rocatin% or
oscillatin%. -t is often a "art of a rotatin%
heel !e.%. an eccentric heel$ or shaft !e.%.
a cylinder ith an irre%ular sha"e$ that
stries a le,er at one or more "oints on its
circular "ath. +he cam can be a sim"le tooth
as is used to deli,er "ulses of "oer to a
steam hammer for eam"le or an eccentric
disc or other sha"e that "roduces a smooth
reci"rocatin% !bac and forth$ motion in the
folloer hich is a le,er main% contact
ith the cam.
+he cam can be seen as a de,ice that
translates from circular to reci"rocatin% !or
sometimes oscillatin%$ motion. 6 common
eam"le is the camshaft of an automobile
hich taes the rotary motion of the en%ineand translates it into the reci"rocatin%
motion necessary to o"erate the intae and
ehaust ,al,es of the cylinders. +he
o""osite o"eration translation of
reci"rocatin% motion to circular motion is
done by a cran. 6n eam"le is the
cranshaft of a car hich taes the
reci"rocatin% motion of the "istons and
translates it into the rotary motion necessary
to o"erate the heels. 8ams can also be
,ieed as information7storin% and
7transmittin% de,ices.
6 cam 9 the folloer combination belon%
to the cate%ory of hi%her "airs. Necessary
elements of a cam mechanism are
6 dri,er member non as the cam
6 dri,en member called the folloer
6 frame hich su""orts the cam 9 %uides
the folloer
6n early cam as built into ;ellenistic
ater7dri,en automata from the *rd century
)8. +he use of cams as later em"loyed by
6l7
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automata. +he cam and camshaft a""eared
in >uro"ean mechanisms from the 14th
century.
+he binary cam is a desi%n for the "ulley
system of a com"ound bo. 8rai% ?ehle
director of research and de,elo"ment at
)otech 6rchery recei,ed a "atent for the
desi%n on December 11 200'. )otech
started e@ui""in% its bos ith the ne cam
desi%n in the 2005 model year.
+he binary cam is described as a modified
tin cam setu" here each cam is sla,ed to
the other ,ia a loo" of strin% connectin% the
to cams. +his is contrasted ith a ty"ical
tin cam setu" here the ends of the
bostrin% are "hysically anchored onto each
of the bo limbs.
6s a tin cam system relies on each cam
rotatin% inde"endently based solely on the
force of the strin% and the resistance of the
bo limbs bein% absolutely symmetrical
there is room for a tin cam system to Alose
tuneA throu%h ear and tear strin% stretch
or ust %eneral a%e. +he effect of a detuned
tin cam bo is that the to cams rotate out
of sync ith each other causin% the
bostrin% to accelerate in to alternatin%
directions u"on release. +his causes a
number of ad,erse conse@uences the most
ob,ious bein% unsteady arro fli%ht.
+he binary cam o,ercomes this by Bsla,in%B
each cam to the otherC as one cam is unable
to rotate ithout the direct e@ui,alent action
of the other the to rotate in near "erfect
synchroni=ation ith any "ossible
differences in rotation automatically
correctin% themsel,es as the shot cycle is
com"leted.
T+PES OF CAMS
8ams are classified accordin% to
1$ Sha"e
2$ olloer mo,ement 9
*$ Manner of constraint of the folloer.
Accord#$ to Shape:,
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-. %ed$e / F!at Cam": 6 ed%e
%enerally has a translational motion. +he
folloer can either translate or oscillate.
S"rin% is used to maintain the contact
beteen the cam 9 the folloer. +he
cam is stationary 9 the folloer causes
the relati,e motion of the cam.
2. Rada! / '"c Cam": 6 cam in hich
the folloer mo,es radially from the
centre of rotation of the cam is non as
a radial or a disc cam.
. Spra! Cam": 6 s"iral cam is a face cam
in hich a %roo,e is cut in the form of a
s"iral. +he s"iral %roo,e consists of teeth
hich mesh ith a "in %ear folloer.
4. Cy!#drca! Cam": 6 cylinder hich
has a circumferential contour cut in the
surface rotates about its ais.
5. Co#1u$ate Cam": 8onu%ate cams are a
double7disc cam the to discs bein%
eyed to%ether 9 are in constant touch
ith the to rollers of a folloer.
6. (!ooda! Cam": 6 %loboidal cam can
ha,e to ty"es of surfaces con,e or
conca,e.
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7. Spherca! Cam": -n a s"herical the
folloer oscillates about an ais
"er"endicular to the ais of rotation of
the cam.
Accord#$ to fo!!o3er mo4eme#t
1. R"e,Retur#,R"e 5R,R,R6: -n this
there is alternate rise 9 return of the
folloer ith no "eriods of dells.
+he folloer has a linear or an
an%ular dis"lacement.
2. '3e!!,R"e,Retur#,'3e!! 5',R,R,
'6: -n such a ty"e of cam there is
rise 9 return of the folloer after a
dell.
3. '3e!!,R"e,'3e!!,Retur#,'3e!!
5',R,',R,'6: -t is the most idely
used ty"e of cam. +he dellin% of
the cam is folloed by rise 9 dell
9 subse@uently by return 9 dell.
Accord#$ to Ma##er of Co#"tra#t of the
Fo!!o3er
1. Pre,!oaded "pr#$ cam: -s used for
the "ur"ose of ee"in% the contactbeteen the cam 9 the folloer.
2. Po"t4e,dr4e cam: 8onstant touch
beteen the cam 9 the folloer is
maintained by a roller folloer
o"eratin% the %roo,e of cam.
3. (ra4ty cam: -f the rise of the cam
is achie,ed by the risin% surface ofthe cam 9 the return by the force of
%ra,ity or due to the ei%ht of the
cam the cam is non as the %ra,ity
cam.
T+PES OF FO&&O%ERS
8am folloers are classified accordin% to
the
1. Sha"e
2. Mo,ement 9
*. ocation of line of mo,ement.
Accord#$ to "hape
1. K#fe,ed$e Fo!!o3er: Sim"le in
construction. ;oe,er its use is
limited as it "roduces a %reat ear of
the surface at the "oint of contact.
2. Ro!!er Fo!!o3er: Eidely used cam
folloer 9 has a cylindrical roller
free to rotate about a "in oint. 6t
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lo s"eed the folloer has a "ure
rollin% action but at hi%h s"eeds
some slidin% also occurs.
Accord#$ to Mo4eme#t
1. Recprocat#$ Fo!!o3er: 6s the
cam rotates the folloer
reci"rocates or translates in the
%uides.
2. O"c!!at#$ Fo!!o3er: +he folloer
is "i,oted at a suitable "oint on the
frame 9 oscillates as the cam maesthe rotary motion.
Accord#$ to &ocato# of e of
Mo4eme#t
1. Rada! Fo!!o3er: +he folloer is
non as a radial folloer if the line
of mo,ement of the folloer "asses
throu%h the center of rotation of the
cam.
2. Off"et Fo!!o3er: -f the line of
mo,ement of the roller folloer is
offset from the center of rotation of
the cam the folloer is non as
offset folloer.
CAM PROFI&ES
DESIGN PRINCIPLE
+he method termed inematic in,ersions is
commonly used in cam "rofile desi%n. or
eam"le in a dis cam ith translatin%
folloer mechanism the folloer translates
hen the cam turns. +his means that the
relati,e motion beteen them is a
combination of a relati,e turnin% motion and
a relati,e translatin% motion. Eithout
chan%in% this feature of their relati,e
motion ima%ine that the cam remains fied.
No the folloer "erforms both the relati,e
turnin% and translatin% motions. Ee ha,e
in,erted the mechanism
Cam Nomenclature
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F )a"e crc!e: -t is the smallest circle
tan%ent to the cam "rofile !contour$
dran from the center of rotation of
a radial cam.
F Trace po#t:-t is the reference "oint
on the folloer to trace the cam
"rofile such as the nife7ed%e
folloer and the center of the roller
of a roller folloer.
Ptch cur4e: -t is the cur,e dranbythe trace "oint assumin% that the cam
is fied and the trace "oint of the
folloer rotates around the cam.
F Pre""ure a#$!e: -t re"resents the
stee"ness of the cam "rofile it is the
an%le beteen the normal to the
"itch cur,e at a "oint and the
direction of folloer motion. -t
,aries in ma%nitude at all instants of
folloer motion.
F Ptch po#t: -t is the "oint on the
"itch cur,e at hich "ressure an%le
is maimum.
F Ptch crc!e: -t is the circle "assin%
throu%h the "itch "oint and
concentric ith the base circle.
F Prme crc!e: +he smallest circle
dran tan%ent to "itch cur,e is
non as the "rime circle.
F A#$!e of A"ce#t 5out"tro7e6: -t is
the an%le turned by cam durin% the
time of rise of folloer.
F A#$!e of '3e!!: -t is the an%le
turned by cam hile the folloer
remains stationary at the hi%hest or
loest "osition.
F A#$!e of de"ce#t 5Retur# "tro7e$:
-t is the an%le turned by cam hen
folloer returns to its initial "osition.
F A#$!e of acto#: -t is the an%le
turned by cam durin% be%innin% of
rise and the end of return of the
folloer.
HI(H,SPEE' CAMS
6 real folloer alays has some mass 9
hen multi"lied by acceleration inertia
force of the folloer is obtained. +his force
is alays felt at the contact "oint of the
folloer ith the cam surface 9 at the
bearin%s. 6n acceleration cur,e ith abru"t
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chan%es eerts abru"t stresses on the cam
surfaces 9 at the bearin%s accom"anied by
detrimental effects such as surface ear 9
noise. 6ll this may lead to an early failure
of the cam system. +hus it is ,ery im"ortant
to %i,e due consideration to ,elocity 9
acceleration cur,es hile choosin% a
dis"lacement dia%ram.
-n lo7s"eed a""lications cam ith
discontinuous acceleration characteristics
may not sho any undesirable characteristic
but at hi%her s"eeds such cams are certainly
bound to sho the same. +he hi%her the
s"eed the hi%her is the need for smooth
cur,es. 6t ,ery hi%h s"eeds e,en the er is
made continuous as ell.
&A+O*T OF CAM PROFI&ES
6 cam "rofile is constructed on the "rinci"le
of inematic in,ersion i.e. considerin% the
cam to be stationary 9 the folloer to be
rotatin% about it in the o""osite direction of
the cam rotation.
G-NH>S-#N
(raphca! Repre"e#tato# of Cam Prof!e
For the ca"e of recprocat#$ 7#fe,
ed$e fo!!o3er
Step-: di,ide the dis"lacement7dia%ram
6bscissa into a number of se%ments.
Step2: di,ide the "rime circle into
8orres"ondin% se%ments.
Step: transfer distances by means of
di,iders from the dis"lacement dia%ram
directly onto the cam layout to locate the
corres"ondin% "ositions of the trace "oint.
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Step8:dra a smooth cur,e throu%h these
"oints. +he cur,e is ust the re@uired cam
"rofile.
For the case of reciprocating
offset roller follower
6s shon in abo,e fi%ure the dis"lacement
dia%ram of the folloer is %i,en sIs
!J$.8onstruct the "late cam "rofile
Step-:construct the "rime circle ith radius
r0.
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Step2:construct the offset circle ith radius
e@ual to the amount of offset e.
Step: di,ide the dis"lacement7dia%ram
abscissa into a number of se%ments.
Step8: di,ide the offset circle into
corres"ondin% se%ments and assi%n station
numbers to the boundaries of these
se%ments.
Step9:construct lines tan%ent to the offset
circle from these station di,idin% the "rime
circle into corres"ondin% se%ments.
Ste"(: transfer distances by means of
di,iders from the dis"lacement dia%ram
directly onto the cam layout to locate the
corres"ondin% "ositions of the trace "oint
alays measurin% outard from the "rime
circle.
Ste"': dra a smooth cur,e throu%h these
"oints. +he cur,e is ust the re@uired cam
"rofile.
*N'ERC*TTIN(
Sometimes it may ha""en that the "rime
circle of a cam is "ro"ortional to "ro,ide a
satisfactory "ressure an%le still the folloer
may not be com"letin% the desired motion.
+his can ha""en if the cur,ature of the "itch
cur,e is too shar".
-t can easily be obser,ed that the
cam cur,e loo"s o,er itself in order to
reali=e the "rofile of the "itch cur,e. 6s it is
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im"ossible to "roduce such a cam "rofile
the result is that the cam ill be undercut 9
become a "ointed cam. No hen the roller
folloer ill be made to mo,e o,er this
cam it ill not be "roducin% the desired
motion.
-t may be obser,ed that the cam ill
be "ointed if the radius of the roller is e@ual
to the radius of cur,ature of the "itch cur,e.
+hus to minimum radius of cur,ature of the
cam "rofile the radius of cur,ature of the
"rime circle must alays be %reater than that
of the radius of the roller.
CAMPRO EN(INE
+he 8am"ro en%ine is the first automoti,e
en%ine e,er de,elo"ed to%ether ith otus
by the Malaysian carmaer roton. +he
name 8am"ro is short for 8am rofilin%.
+his en%ine "oers the roton en72 the
roton Satria Neo the roton Eaa 8am"ro
the roton ersona as ell as rotonBs future
models. +he 8am"ro en%ine is aimed to
sho rotonBs ability to mae their on
en%ines that "roduce %ood "oer out"ut and
meet neer emission standards.
6ll 8am"ro en%ines incor"orate
dri,e7by7ire technolo%y !s"ecifically
electronic throttle control$ for better
res"onse eliminatin% the need for friction7
%eneratin% mechanical lina%es and cables.
REFERENCE
1. htt"://.%oo%le.co.in/ima%esL
hlIen9@Icam"rofiles9umI19ieI
3+7
9sourceIuni,9eiI2yOc+MeN#M
Eecf)5MP9saIO9oiIima%eQresultQ%rou"9ctItitle9resnumI*9,ed
I08DPPs6P6%9biI10249bih
I(0(
2. htt"://.technolo%ystudent.com/c
ams/cam2.htm
*. htt"://hdabob.com/8am
R20rofiles.htm
4. htt"://.mar"oss.com/"roduct."h
"/en%/camshaftQ"rofileQautomaticQin
s"ection
5. htt"://.technolo%ystudent.com/c
ams/cam2.htm
(. htt"://.ma"lesoft.com/a""licatio
ns/,ie.as"LS-DI*25'
'. htt"://.cs.cmu.edu/ra"id"roto/
mechanisms/ch"t(.html
. htt"://.ise%ee.com/hat7is7a7
camshaft.htm
&. htt"://mech"roects.blo%s"ot.com/20
0/01/technical7terms7used7in7cam7
dia%ram.html
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