Fourth year, Department of Mechanical Sandwich
Engineering
First and second Units Questions.
PART-A (10 x 2 = 20 Marks)
1. Whatis the
formula of power transmitted?
2.Stresses in the belt
drive?
3. Stresses due to
the effect of centrifugal force?
4.Types of belts?
5.What is meant by
flat belt drive?
6.Draw the diagram
of open belt drive?
7.What is the ratio
of number of v-belts?
8.Classification of
ropes?
9.What is the
formula of effective stress?
10. Types of chain
drives?
PART-B
(5×16=80 Marks)
11. Design a cast iron pulley to
transmitted 20KW at 300rpm. The diameter of the pulley is 500mm and angle of
lap 108◦.the pulley has four arms of elliptical cross-section with major axis
twice the minor axis. The co-efficient of friction between the belt and the
pulley surface is 0.3; the allowable belt tension is not to exceed 250N in 10mm
width. The allowable shear stress for the shaft material may be taken as 50N/mm.
12. Design an overhanging pulley
for the follow able specification power18KW, speed200rpm, angle of
contact165◦,co-efficient of friction 0.25,ocerhanging length0.3.belt thickness10mm.shaft
shear stress 40MPa.shaft stress for belt
2.5MPa.shaft stress or rim4MPa.density of the leather 100kg/m3.
13. It is a required to select a
flat belt drive for a fan running at 360rpm.which is driven by a10KW, 1440rpm
motor. The belt drive open type and space available for a centre distance of 2m
approximately, the diameter of a driven pulley is 1000mm.
14. Design a wire rope for an elevator in a
building 60m, high and for a total load of 20KN the speed of the elevator is
4m/sec and the full speed is reached in 10sec.
15. A truck equipped with a9.5KW
engine was a roller chain as the final drive to the rear axle. the driving
sprocket runs at 900rpm. And the driven sprocket at 400rpm.with a centre
distance of approximately 600mm, select the roller chain.
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