Download AKTU (Dr. A.P.J. Abdul Kalam Technical University (AKTU), formerly Uttar Pradesh Technical University (UPTU) B-Tech 5th Semester (Fifth Semester) 2016-2017 Kinematics Of Machines Nme 502 Question Paper
(Following Paper ID and Roll No to be ?lled' 1n your
Answer Books)
I?upm? ll): 20l2252 Roll No,
B.TECH ?
Regular Theory Examination (Odd Sem-V), 2016-17
KINEMATICS OF MACHINES
' Time : 3 Hours Max. Marks : 100
Note : Assume any missing data.
SECTION -A
1. Attempt all parts. All parts carry equal marks. Write
answer of each part in short. (10XZ=20)
a) De?ne the term machine and mechanism.
b) De?ne instantaneous centre.
c) ' State the condition for a link to experience coriolsis
acceleration.
d) What is chebyshev spacing?
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NME - 502 . ' ? "NME - 502
e) Name any two types of cams with speci?ed _
contours. . - r.p.m. clockwise. When the crank has turned 45? from
the inner dead centre position, determine:
f) De?ne pressure angle with respect to cam. .
_ ? . a) Velocity of the sliderA,
g) De?ne module of gears and its relation to? circular
pitch. . b) Velocity of the point G, and
h) What are the special advantages of epicyclic gear ' ic) Angular velocity ofthe connecting rod AB.
trains? ?
4. In'a pin jointed four bar mechanism ABCD, the lengths
i) What are the dlsadvantages OfV- belt dr1ve OVCI' ?at of various links areas follows;
belt? ' AB = 25 mm;?BC = 87.5 mm; CD = 50 mm and AD = 80
. mm. The link AD is ?xed and
j) What is the function of friction clutch? '
SECTION - B .
Note: Attempt any ?ve questions from this section.
(5X 1 0=50)
2. Sketch and explain any two inversions of single slider
crank chain.
3. In a slider crank mechanism, in ?g.1 . the length of crank
OB and connecting rod AB are 125 .mm and 500 mm , the angle BAD? ? 135?. If the velocity of B is 1. 8m/s in
the clockwise direction, ?nd velocity and acceleration '
respectively. The centre of gravity G of the connecting ofth e m d t fBC
1 poin 0
rod is 275 mm from the sliderA. The crank speed is 600
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NME - 502
What are straight line mechanisms? Describe one type
of exact straight line inotion mechanism with the help of
a sketch.
A pinion having 20 involute teeth of module pitch 6mm
rotates at 200 rpm. and transmits1.5 kW to a gear wheel
having 50 teeth. The addendum on both the wheels is 1/4
of the circular pitch. The angle of obliquity is 20?. F ind
a) The length of the path of approach.
b) The length of the arc of approach.
'c) The normal force between the teeth at an instant
where there is only pair of teeth in contact.
Explain with a neat sketch the ?sun and planet wheel. ?
Explain with sketches the different types of cams and
followers.
A conical pivot supports a load of 20 kN, the cone angle
is 1200 and the intensity of normal pressure is not to
exceed 0.3 N/mmzi- The external diameter is twice the
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NME - 502
internal diameter; F ind the outer and inner radii of the
bearing Surface. If the shaft rotates at 200 r.p;m. and the
coef?cient of friction is 0.1, ?nd the power absorbed in
friction. Assume uniform pressure.
SECTION - C
Note : Attempt any two questions from this section. 5
10.
11.
? (2xis=3o)
a) Explain different kinds of kinematic pairs giving
example for each one of them. (10)-
b) What is the condition for correct steering? Explain
Ackerman steering gear. . (5),
a) Determine the width of a 9.75 mm thick leather belt
required to transmit 15 kW from a motor running
at 900 r.p.m. The diameter of the driving pulley of
the mdtor is 300 mm. The driven pulley runs at 300
r.p.m. and the distance between the centres of two
pulleys is 3 meters. The density of the leather is
? 1000 kg/m3. The maximum allowable stress in the
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leather is 2.5 MPa. The coef?cient of friction
between the leather and pulley is 0.3. Assume open
belt drive and neglect the sag and slip of the belt.(9)
b) Brie?y explainthe following:
i) ~ Slip of the belt
ii) Creep of the belt. I (6)
12. A cam rotating clockwise with a uniform speedis to give
the roller followei of 20 mm diameter with the following
motion :
3) Follower to move outWards through a distance of
30 mm during 120? of cam rotation;
b) Follower to dwell for 60? of 0am rotation.
c) F ollower to return to its initial position during 90?
of cam rotation; and
d) Follower to dwell for the remaining 90? of cam
rotation.
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The minimum radius of the cam is 45 mm and the line of
stroke of the follower is offset 15 mm from .the axis of
the cam and the displacement of the follower is to take
place with simple harmonic motion on both the outward
and return strokes. Draw the cam pro?le. .
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This post was last modified on 29 January 2020