K.S.K COLLEGE OF ENGINEERING AND TECHNOLOGY ELEMENTYEAR/SEM: III/V
ME6503- DESIGN OF MACHINE
2- MARKS UNIT-1 STEADY STRESSES AND VARIABLE VARIABLE STRESSES IN MACHINE MEMBERS
1. State the factors influencing the machine design? 2. What is factor of safety? 3. What are the various theories of failures? 4. Discuss about maximum principal stress theory. . !xplain about maximum shear stress theory ". Describe about maximum principal strain theory. #. $riefly discuss about stress concentration. %. What are the different failure modes of machine component? &. What is meant by design stress or 'or(ing stress? 1).What are steps involved in design process. UNIT-2 DESIGN OF SHAFTS AND COUPLINGS
1. Specify the types of shafts. 2. What is the significance of slenderness ratio in shaft design? 3. Define critical speed of shaft. 4. !xplain torsional stiffness of the shaft. . What is (ey? Describe the types of (eys. (e ys. ". What is coupling? Describe the types of cou plings #. What are the stresses induced in shaft? %. What is the effect of (ey'ay cut into the shaft? &. Differentiate *oint and coupling. 1).What is the difference bet'een axle and spindle? UNIT-3 DESIGN OF TEMPORARY PERMANENT JOINTS
1. Define the types of 'eld *oints. 2. What is meant by throat thic(ness? 3. What is rivet and 'here is it used? 4. Specify the types of rivets. . What is the difference bet'een chain riveting and +ig,+ag riveting? 1 MUTHAMIZHAN. T[A/MECH!
KSKCET
K.S.K COLLEGE OF ENGINEERING AND TECHNOLOGY ELEMENTYEAR/SEM: III/V
ME6503- DESIGN OF MACHINE
". What is the difference bet'een nominal diameter and gross diameter of rivet? #. Define efficiency of a riveted *oint. %. What is cotter *oint " &. What is (nuc(le *oint? 1).-ive some examples for permanent and temporary *oints. 11.Define the terms ma*or diameter minor diameter pitch and lead in threaded fasteners. 12.What are the merits and demerits of scre' *oints? 13.Define thread angle. 14.-ive examples of temporary and permanent fasteners. 1./ist out the types of butt *oint. 1".What are the advantages and disadvantages of threaded *oints? 1#.S(etch any t'o types of 'eld *oints. UNIT-4 DESIGN OF ENERGY STORING ELEMENTS
1. Define variable load and give some applications. 2. What is fatigue strength? 3. Describe the classification of springs. 4. What is free length of helical spring? . Define spring rate and spring index. ". What is pitch and solid length of spring? #. What do you mean by endurance limit? UNIT-5 DESIGN OF BEARINGS
1. What is *ig? Define fixture. 2. State the ob*ectives of *ig design. 3. State the types of clamping devices. 4. What are the different types of *igs? . Write do'n the three types of errors that are accounted for *ig and fixture design? ". Differentiate *ig and fixture.
#. !xplain briefly six point locating principles.
16- MARKS
# MUTHAMIZHAN. T[A/MECH!
KSKCET
K.S.K COLLEGE OF ENGINEERING AND TECHNOLOGY ELEMENTYEAR/SEM: III/V
ME6503- DESIGN OF MACHINE
UNIT-I STEADY STRESSES AND VARIABLE STRESSES IN MACHINE MEMBERS 1.
2.
0he frame of a punch press is sho'n in fig. ind the stresses at the inner and outer surface at section , of the frame if W ))) . 567 89: 2)14;
6 hot rolled steel shaft is sub*ected to a torsional moment that varies from 33) , m cloc('ise to 11) ,m counter cloc('ise and an applied bending moment at a critical section varies from 44) ,m to ,22) ,m. 0he shaft is of uniform cross,section and no (ey'ay is present at the critical section. Determine the re
3.
6 cast,iron lin( as sho'n in figure is to carry a load of 2) (. >f the tensile and compressive stresses in the lin( are not to exceed 2 8=a and %) 8=a respectively obtain the dimensions of the cross,section of the lin( at the middle of its length. 567 9D 2)13;
4.
2
6 machine component is sub*ected to fluctuating stress that varies from 4) to 1)) 9mm . 0he 2
corrected endurance limit stress for the machine component is 2#) 9mm . 0he ultimate tensile 2
strength and yield strength of material are ")) and 4) 9mm respectively. ind the factor of safety using @iA -erber theory @iiA Soderberg line @iiiA -oodman line and @ivA 6lso find factor of safety against static failure. 567 89: 2)13; 5.
6 B,clamp is sub*ected to a maximum load of W as sho'n in figure. >f the maximum tensile stress in the clamp is limited to 14) 8=a. ind the value of load W.
3 MUTHAMIZHAN. T[A/MECH!
KSKCET
K.S.K COLLEGE OF ENGINEERING AND TECHNOLOGY ELEMENTYEAR/SEM: III/V
ME6503- DESIGN OF MACHINE
567 9D 2)12; 6. 6 pulley is (eyed to a shaft mid'ay bet'een t'o bearings. 0he shaft is made of cold dra'n steel for 'hich the ultimate strength is ) 8=a and the yield strength is 4)) 8=a. 0he bending moment at the pulley varies from ,1) ,m to C4)) ,m as the tor
567 9D 2)12;
6 pulley is (eyed to a shaft mid'ay bet'een t'o anti, friction bearings. 0he bending moment at the pulleys varies from ,1") ,m to C)) ,m and the torsional moment in the shaft varies from ") , m to C1") ,m. 0he fre
8.
6 cast iron pulley transmits 1) (W at 4)) rpm. 0he diameter of the pulley is 1.2 m and it has four straight arms of elliptical cross,section in 'hich the ma*or axis is t'ice the minor axis. Determine the dimensions of the arm if the allo'able bending stress is 1 8=a. 567 9D 2)11;
9.
6 circular bar of )) mm length is supported freely at its t'o ends. >t is acted upon by a central concentrated cyclic load having a minimum value of 2) ( and a maximum value of ) (. Determine the diameter of bar by ta(ing a factor of safety of 1. si+e effect of ).% surface finish factor of ).&. 0he material properties of bar are given by ultimate strength of ") 8=a yield strength of )) 8=a and endurance strength of 3) 8=a.
1).
567 9D 2)11;
6 'all brac(et 'ith a rectangular cross section sis sho 'n in fig. 0he depth of the cross section is t'ice the 'idth. 0he force = acting on the brac(et at ")F to the vertical is (. 0he material of the brac(et is grey cast iron -2)) and the factor of safety is 3.. Determine the dimensions of the cross section of the brac(et. 6ssume maximum principal stress theory of failure.
11.
2
567 89: 2)11;
2
6 steel rod of yield strength 3) 9mm and endurance limit of 2" 9mm is sub*ected to an axial load 'hich varies from ,3)) ( minimum to #)) ( maximum and has a stress concentration factor 1.%.
6ssume factor of safety 2. Balculate the diameter of the steel rod. $ MUTHAMIZHAN. T[A/MECH!
KSKCET
12.
6 bolt is sub*ected to a tensile load of 2 ( and to a shear load of 1) (. Suggest a suitable si+e of a bolt 2
according to various theories of failure. 0a(e allo'able yield stress is 3)) 9mm =oissonGs ).2. 567 9D 2)1); 13.
6 ) mm diameter shaft is made from carbon steel having ultimate tensile strength of ")) 8=a. >t is sub*ected to a tor
14.
!xplain in short the stress concentration factor and methods o f relieving stress concentrations. @% 8ar(sA 567 89: 2)11;
1.
Discuss in detail about the factors influencing machine design.
@% 8ar(sA 567 89: 2)12 89: 2)14;
1".
Write short notes on preferred numbers fits
@% 8ar(sA 567 89: 2)12;
17.
types of fits.
!xplain various phases in Design using a flo' diagram and enumerate the factors influencing the machine design.
18.
@12 8ar(sA 567 89: 2)13;
What is meant by hole basis system and shaft basis s ystem? Which one is preferred and 'hy? @4 8ar(sA 567 89: 2)13;
19.
What is the difference bet'een -erber curve and soderberg and -oodman lines? @" 8ar(sA 567 89: 2)13;
20.
Write short notes on the follo'ing @iA >nterchangeability @iiA 0olerance @iiiA 6llo'ance @" 8ar(sA 567 89: 2)14;
21.
What is factor of safety? /ist the factors to be considered 'hile deciding the factor of safety. @" 8ar(sA 567 89: 2)14;
UNIT-II DESIGN OF SHAFTS AND COUPLINGS 1.
6 steel solid shaft transmitting 1 (W at 2)) r.p.m. is supported on t'o bearings #) mm apart and has t'o gears (eyed to it. 0he pinion having 3) teeth of mm module is located 1)) mm to the left of the right hand bearing and delivers po'er hori+ontally to the right. 0he gear having 1)) teeth of mm module is located 1) mm to the right of the left hand bearing and rece ives po'er in a vertical direction from belo'. 7sing an allo'able stress of 4 8=a in shear determine the diameter of the shaft.
567 89: 2)14
89: 2)13;
6 hoisting ). m 0he ingear diameter is (eyed tois aand shaft 'hich is supported inend t'oof bearings through aas 12 reduction ratio by an electric motor. Determine the po'er of the driving motor the maximum load of driven %may ( is hoisted atin a2tension speed of m9min the efficiency of the drive is shoc( %)H. 6lso determine the tor
6 hori+ontal nic(el steel shaft rests on t'o bearings. 6 at the left and $ at the right end and carries t'o gears B and D located at distances of 2)mm and 4))mm respectively from the centre line of the left and right bearings. 0he pitch diameter of the gear B is "))mm and that of gear D is 2))mm. 0he distance bet'een the centre line of the bearings is 24))mm. 0he shaft transmits 2) (W at 12) rpm. 0he po'er is delivered to the shaft at gear B and is ta(en out at gear D in such a manner that the tooth pressure tB of the gear B and tD of the gear D act vertically do'n'ards. ind the diameter of the shaft if the 'or(ing stress is 1)) 8=a in tension and " 8pa in shear. gear B and D 'eighs &) and 3) respectively. 0he combined shoc( and fatigue factors for bending and torsion may be ta(en as 1. and 1.2 respectively. 567 9D 2)12;
4.
Design a shaft to transmit po'er from an electric motor to a lathe head stoc( through a pulley by means of a belt drive. 0he pulley 'eighs 2)) and is located at 3)) mm from the centre of the bearing. 0he diameter of the pulley is 2)) mm and the maximum po'er transmitted is 1 (W at 12) r.p.m. 0he angle of lap of the belt is 1%)F and coefficient of friction bet'een the belt and the pulley is ).3. 0he shoc( and fatigue factors for bending and t'isting are 1. and 2.) respectively. 0he allo'able shear stress in the shaft may be ta(en as 3 8=a. 567 9D 2)11;
5.
0he layout of a transmission shaft carrying t'o pulleys $ and B and supported on bearings 6 and D is sho'n in fig. =o'er is supplied to the shaft by means of a vertical belt on pulley $ that is t hen transmitted to the pulley B carrying a hori+ontal belt. 0he maximum tension in belt on pulley $ is 2. (. 0he angle of 'rap for both pulleys is 1%) and coefficient of friction is ).24. 0he shaft is made of plain carbon steel 3)B% @S yt 4)) 9mm2A and the factor of safety is 3. Determine the shaft diameter on strength basis. 567 89: 2)11;
6.
6 hollo' shaft for a rotary compressor is to be designed to transmit a maximum tor
7.
567 9D 2)1);
Determine the dimensions of flange coupling that connects a motor and a pump shaft. 0he po'er to be transmitted a 2 (W at a shaft speed of &") rpm. Select suitable materials for the parts of the coupling and list the dimensions.
8.
567 89: 2)14;
Design a rigid flange coupling to transmit a tor
1)) 8=a
$earing or crushing stress on shaft
2) 8=a
Shear stress on (eys
1)) 8=a
$earing stress on (eys
2) 8=a
Shearing stress on cast iron
2)) 8=a
Shearing stress on bolt
1)) 8=a
6fter designing the various elements ma(e a neat s(etch of the assembly indicating the important dimensions. 0he stresses developed in the various members may be chec(ed if thumb rules are using for fixing the dimensions. 567 9D 2)13; 9.
6 rigid type of coupling is used to connect t'o shafts transmitting 1 (W at 2)) rpm. 0he shaft (eys and bolts are made of B4 steel and the coupling is of cast iron. Design the coupling. 567 89: 2)13;
10.
Design a bushed,pin type of flexible coupling to connect a pump shaft to a motor shaft transmitting 32 (W at &") rpm. 0he overall tor
0he allo'able shear and crushing stress for shaft and (e y material is 4) 8=a and %) 8=a respectively
ii
0he allo'able shear stress for cast iron is 1 8=a
iii iv
0he allo'able bearing pressure for rubber bush is ).% 9mm 2 0he material of the pin is same as that of shaft and (ey.
Dra' neat s(etch of the coupling. 11.
567 9D 2)12;
Design a muff coupling to connect t'o shafts transmitting 4) (W at 12) rpm. 0he shear and crushing stress for the shaft and (ey material are 3) 8=a and %) 8=a respectively. 0he material of muff is cast iron 'ith permissible shear stress of 1 8=a. 6ssume that the maximum tor
12.
0'o 3 mm shafts are connected by a flanged coupling. 0he flanges are fitted 'ith " bolts on 12 mm bolt circle. 0he shafts transmit a tor
13.
Safe shear stress for shaft material
"3 8=a
Safe stress for bolt material
" 8=a
Safe stress for cast iron coupling
1) 8=a
Safe stress for (ey material
4" 8=a
567 9D 2)11;
Design a cast iron protective type flange coupling to transmit 1 (W at &)) r.p.m. from an electric motor to a compressor. 0he service factor may be assumed as 1.3. 0he follo'ing permissible stresses may be used Shear stress for shaft bolt and (ey material 4) 8=a Brushing stress for bolt and (ey %) 8=a Shear stress for cast iron % 8=a Dra' a neat s(etch of the coupling.
14.
567 89: 2)11;
Design a protective type flange coupling to connect t'o shafts to transmit 1 (W at ")) rpm.
567 9D 2)1); 15.
Design a plain carbon steel centre cran(shaft for a single acting four stro(e single cylinder engine for the follo'ing data =iston diameter 2)) mmE Stro(e 4)) mmE 8aximum combustion pressure 2.) 9mm 2 Weight of the fly'heel 1 ( 0otal belt pull 3 /ength of connecting rod &)) mm When the cran( has turned through 3) from top dead centre the pressure on the piston is 1 9mm 2 and the tor
UNIT-III DESIGN OF TEMPORARY PERMANENT JOINTS
1.
6 ) mm diameter solid shaft is 'elded to a flat plate as sho'n in fig. >f the si+e of the 'eld is 1 mm find the maximum normal and shear stress in the 'eld.
2.
567 89: 2)14;
ind the maximum shear stress induced in the 'eld of " mm si+e 'hen a channel as sho'n in fig is 'elded to a plate and loaded 'ith 2) ( force at a distance of 2)) mm.
3.
567 9D 2)13;
6 rectangular steel plate is 'elded as a cantilever to a vertical column and supports a single concentrated load = as sho'n in ig. Determine the 'eld si+e if shear stress in the same is not to exceed 14) 8=a.
567 89: 2)13; 567 9D 2)12;
4.
6 rectangular cross,section bar is 'elded to a support by means of fillet 'elds as sho'n in ig. Determine the si+e of the 'elds if the permissible shear stress in the 'eld is limited to # 8=a. 567 9D 2)11;
5.
6.
7.
6 brac(et is 'elded to the vertical plate by means of t'o fillet 'elds as sho'n in fig and is sub*ected to an eccentric load of 2)) . Determine the si+e of the 'elds if the permissible shear stress is limited to ) 9mm2. 567 89: 2)11; 6 plate of 2)) mm 'idth is 'elded to a vertical plate by fillet 'elding on three sides to form a cantilever 'ith an overlap of 1) mm and overhang of 4)) mm. 6 vertical do'n'ard load of 3 ( is applied at free end for a 'eld stress of # 9mm 2. Determine the si+e of the 'eld. 567 9D 2)1); 0'o length of mild steel tie rod having 'idth 2)) mm are to be connected by means of /o+enge *oint 'ith t'o cover plates to 'ithstand a tensile load of 1%) (. Bompletely design the *oint if the permissible stresses are %) 8=a in tensionE " 8=a in shear and 1") 8=a crushing. Dra' a neat s(etch of the *oint.
8.
567 89: 2)12;
What is an eccentric loaded 'elded *oint? Describe procedure for designing such a *oint. @% 8ar(sA 567 89: 2)13
9.
89: 2)14;
6 cast iron cylinder head is fastened to a c ylinder of )) mm bore 'ith % stud bolts. 0he maximum pressure inside the cylinder is 2 8=a. 0he stiffness of part is thrice the stiffness of the bolt. What should be the initial tightening load so that the point is lea( proof at maximum pressure? 6lso choose a suitable bolt for the above application. 567 89: 2)14;
10.
or supporting the travelling crane in a 'or(shop the brac(ets are fixed on steel columns as sho'n in ig. 0he maximum load that comes on the brac(et is 12 ( acting vertically at a distance of 4)) mm from the face of the column. 0he vertical face of the brac(et is secured to a column by four bolts in t'o ro's @t'o in each ro'A at a distance of ) mm from the lo'er edge of the brac(et. Determine the si+e of the bolts if the permissible value of the tensile stress for the bolt materia l is %4 8=a. 6lso find the cross, section of the arm of the brac(et 'hich is rectangular.
567 9D 2)13;
11.
6 steam engine of effective diameter 3)) mm is sub*ected to a steam pressure of 1. 9mm2. 0he cylinder head is connected by % bolts having yield point 33) 8=a and endurance limit at 24) 8=a. 0he bolts are tightened 'ith an initial preload of 1. times the steam load. 6 soft copper gas(et is used to ma(e the *oint lea(,proof. 6ssuming a factor of safety 2 find the si+e of bolt re
12.
567 89: 2)11;
Design and dra' a cotter *oint to support a load varying from 3) ( in compression to 3) ( in tension. 0he material used is carbon steel for 'hich the follo'ing allo'able stresses may be used. 0he load is applied statically. 0ensile stress compressive stress ) 8=aE shear stress 38=a and crushing stress&) 8=a. 567 89: 2)13;
13.
Design a (nuc(le *oint to transmit 1) (. 0he design stresses may be ta(en as # 8=a in tension ") 8=a in shear and 1) 8=a in compression.
14.
567 9D 2)12 9D 2)11;
Design and dra' a (nuc(le *oint to connect t'o mild steel bars under a tensile load of (. 0he allo'able stresses are " 8=a in tension ) 8=a in shear and %3 8=a in crushing. 567 89: 2)12;
UNIT-IV DESIGN OF ENERGY STORING ELEMENTS 1.
6 close,coiled helical compression spring has plain ends and is to fit over a 2 mm diameter rod. When a compressive force of 1)) is applied to the spring it compresses by ) mm. >f the spring has a maximum allo'able shear stress of 1%) 89m 2 and a modulus of rigidity of %1 -9m 2 determine @iA the mean coil diameter of the spring @iiA the diametrical clearance bet'een the spring and the rod @iiiA the number of coil in the spring @ivA the solid length of the spring.
2.
567 89: 2)14;
6 helical compression spring made of oil tempered carbon steel is sub*ected to a load 'hich varies from 4)) to 1))) . 0he spring index is " and the design factor of safety is 1.2. >f the yield stress in shear is ##) 8=a and endurance stress in shear is 3) 8=a find @iA Si+e of the spring 'ire @iiA Diameter of the spring @iiiA umber of turns of the spring and @ivA ree length of the spring. 0he compression of the spring at the maximum load is 3) mm. 0he modulus of rigidity for the spring material ma y be ta(en as
3.
%) (9mm2. 567 9D 2)13; 2 6 safety valve of ") mm diameter is to blo' off at a pressure of 1.2 9mm . >t is held on its seat by a close coiled helical spring. 0he maximum lift of the valve is 1) mm. Design a suitable compression spring of spring index and providing an initial compression of 3 mm. 0he maximum shear stress in the materials of the 'ire is limited to )) 8=a. 0he modulus of rigidity for the spring material is %) (9mm 2. Balculate @iA Diameter of the spring 'ire @iiA 8ean coil diameter @iiiA umber of active turns @ivA =itch of the coil. 567 89: 2)13;
4.
Design a helical spring for a spring loaded safet y valve @Iamsbottom safety valveA for the follo'ing 2
conditions Diameter of the valve seat " mmE perating pressure ).# 9mm E 8aximum pressure 2
'hen the valve blo's off freely ).# 9mm E 8aximum lift of the valve 'hen the pressure rises from
2
).# to ).# 9mm 3. mmE maximum allo'able stress ) 8=aE 8odulus of rigidity %4 2 (9mm E Spring index ". 567 9D 2)12; J 567 89: 2)12; 5.
6 locomotive semi elliptical laminated spring has an overall length of 1 m and sustains a load of #) ( at its centre. 0he spring has 3 full length leaves and 1 graduated leaves 'ith a central band of 1)) mm 'idth. 6ll the leaves are to be stressed to 4)) 8=a 'hen fully loaded. 0he ratio of the total spring depth 2
to that of 'idth is 2. 0a(e.DetermineyoungGs@iAthethic(ness anmodulus'idthofthe i leaves @iiA the initial gap that should be provided bet'een the full length and graduated leaves before the band load is applied and @iiiA the load exerted on the band after the spring is assembled. 567 9D 2)11; 6.
Design a helical compression spring for a maximum load of 1)) for a deflection of 3) mm using the 2
valve of spring index as . 6ssume maximum permissible shear stress for spring 'ire as 42) 9mm 2
7.
and 8odulus of rigidity %4 (9mm 567 89: 2)11; Design a leaf spring for a truc( to the follo'ing specifications 8aximum load on the spring
14) (
o of spring
4
8aterial for spring chromium vanadium steel
8.
2
=ermissible tensile stress Span of spring
")) 9mm 1))) mm
=ermissible deflection
%) mm
KoungGsdulus ofmothespring
2)) 9mm
2
567 89: 2)11;
Design a closed coiled helical compression spring for a load range varying from 2.2 ( to 2.# ( and corresponding axial deflection of " mm. Spring index is . =ermissible shear stress is 4)) 9mm and
2
2
9.
567 9D 2)1); modulus of rigidity is %) (9mm . 0he areas of the turning moment diagram for one revolution of a multi cylinder engine 'ith reference to
the mean turning moment belo' and above the line are ,32 C4)% ,2"# C333 ,31) C22" ,3#4 2
L2") and ,244 mm . 0he scale for abscissa and ordinate are 1 mm 2.4 and 1 mm ") ,m respectively. 0he mean speed is 3)) rpm 'ith a percentage speed fluctuation of L1.H. >f the hoop stress in the material of the rim is not to exceed ." 8=a determine the suitable diameter and cross section for the fly'heel assuming that the 'idth is e
ta(en as #2)) (g9m . eglect the effect of the boss and arms. 567 89: 2)14; 10.
6 single cylinder double acting steam engine delivers 1% (W at 1)) rpm. 0he maximum fluctuation of energy per revolution is 1 percent of the energy developed per revolution. 0he speed variation is limited to 1 percent either 'ay from the mean. 0he mean diameter of the r im is 2.4 mm. Design and dra' the vie's of the fly'heel. 567 9D 2)13;
11.
6 8achine punching 3% mm holes in 32 mm thic( plate re
12.
Design and dra' a cast iron fly'heel used for a four stro(e >.B engine developing 1%) (W at 24) r.p.m. 0he hoop
or centrifugal stress developed in the fly'heel is .2 8=a the total fluctuation of speed is to be limited to 3H of the mean speed. 0he 'or( done during the po'er stro(e is 193 more than the average 'or( done during the 'hole cycle. 0he maximum tor
6n engine runs at a constant load at a speed of 4%) rpm. 0he cran( effort diagram is dra'n to a scale 1 mm 2)) ,m tor
14.
6 multi,cylinder engine is to run at a constant load at a speed of ")) r.p.m. n dra'ing the cran( effort diagram to a scale of 1 m 2) ,m and 1 mm 3M the areas in s< mm above and belo' the mean tor
UNIT-V DESIGN OF BEARINGS
1.
2.
3.
Design a *ournal bearing for a centrifugal pump 'ith the follo'ing data Diameter of the :ournal
1) mm
/oad on bearing
4) (
Speed of *ournal
&)) rpm
567 89: 2)14;
Design a *ournal bearing for a centrifugal pump for the follo'ing data /oad on the *ournal 2))))E Speed of the *ournal &)) rpmE 0ype of oil is S6! 1) for 'hich the absolute viscosity at BE 8aximum bearing pressure for the pump 1. 9mm 2. Balculate also mass of the lubricating oil re
the atmospheric temperature as 1" B and operating temperature of oil as ") B. 6ssume viscosity of oil 2
as 23 s9m . 4.
6 *ournal bearing 1) mm diameter and 3)) mm long carries a radial load of & ( at 12)) rpm. 0he diametral clearance is ).)# mm. >f " (W is being lost in friction 'hat is the viscosity of the oil used at given operating temperature?
5.
567 89: 2)13;
567 9D 2)12;
0he load on the *ournal bearing is 1) ( due to turbine shaft of 3)) mm diameter running at 1%)) rpm. Determine the follo'ing @iA /ength of the bearing if the allo'able bearing pressure is 1." 9mm2 and @iiA 6mount of heat to be removed by the lubricant per minute if the bearing temperature is ") B and viscosity of the oil at ") B is ).)2 (g9ms and the bearing clearance is ).2 mm. 567 9D 2)11;
6.
6 *ournal bearing is to be designed for a centrifugal pump for the follo'ing data /oad on the *ournal
12 (
Diameter of the *ournal
# mm
Speed
144) rpm
6tmospheric temperature of the oil
1" B
perating temperature of the oil
") B
6bsolute viscosity of oil at ") B
).23 (g9m,s 567 89: 2)12;
-ive a systematic design of the bearing.
7.
6 full *ournal bearing of ) mm diameter and 1)) mm long has a bearing pressure of 1.49mm 2. 0he speed of the *ournal is &)) rpm and the ratio of *ournal diameter to the diametral clearance is 1))). 0he bearing is lubricated 'ith oil 'hose absolute viscosity at the operating temperature of # B may be ta(en as ).)11 (g9m,s. 0he room temperature is 3 B. ind @iA the amount of artificial cooling re
8.
Select a suitable deep groove ball bearing for supporting a radial load of 1) ( and an axial load of 3 ( for a life of 4))) hrs at %)) rpm. Select from series "3. Balculate the exp ected life of the selected bearing.
9.
567 698 2)11;
567 9D 2)12; 567 89: 2)13;
Select a bearing for a 4) mm diameter shaft rotates at 4)) rpm. Due to bevel gear mounted on the shaft the bearing 'ill have to 'ithstand a ))) radial load and a 3))) thrust load. 0he life of the bearing expected to be at least 1))) hrs.
10.
567 89: 2)14;
6 Single ro' deep groove ball bearing operating at 2))) rpm is acted by a 1) ( radial load and % ( thrust load. 0he bearing is sub*ected to a light shoc( load and the outer ring is rotating. Determine the rating life of the bearing.
567 9D 2)1);
Determine the dimension of an >,section connecting rod for a petrol engine from the follo'ing data 11) mm = Diameter of piston 11.
8ass of reciprocating parts
=
2 (g
=
32 mm
=
1) mm
=
1)) 'ith possible over speed of 2))
/ength of connecting rod rom centre to centre Stro(e length I.=.8 Bompression ratio 8aximum explosion pressure
12.
Design a suitable connecting rod for a petrol engine for the follo'ing details Diameter of the piston 1)) mmE Weight of reciprocating parts per cylinder 2) E Bonnecting rod length 3)) mmE 2
Bompression ratio #1E 8aximum explosion pressure 3 9mm E Stro(e 14) mmE Speed of the engine 2))) rpm. 567 9D 2)12; 13.
6 connecting rod is re.B engine. 0he follo'ing data are available. Diameter of piston
%% mm
8ass of reciprocating parts
1." (g
/ength of connecting rod @centre to centreA 3)) mm stro(e 12 mm I=8
22)) @'hen developing ) (WA
=ossible over speed
3))) rpm
Bompression ratio
".%1 @approximatelyA 2
=robable maximum explosion pressure @assumed shortly after dead centre at ab out 3 A 3. 9mm . Dra' fully dimensional dra'ings of the connecting rod sho'ing the provision for the lubrication. 567 89: 2)12; 14.
Design a mild steel connecting rod 'ith an >,section for a single cylinder >B engine from the follo'ing data Diameter of the piston is ).1)4 mE 'eight of reciprocating parts is 1%.2 E length of conn ecting rod center to center is ).314 mE stro(e length is ).41 mE speed of the engine is 1)) rpmE maximum explosion pressure is 2.2% 8=a. 6ssume that the maximum thrust ta(es place at 0DB during the explosion stro(e. 6ssume also any missing data.
567 9D 2)11;
