Wednesday, October 19, 2016
Roll No. Total No. of Pages : 3
Total No. of
Questions : 09
B.Tech. (Sem.-6)
AUTOMOTIVE DESIGN-II
Subject Code : AE-302
Paper ID : [Ao719]
Time : 4 Hrs. Max.
Marks : 60
INSTRUCTION TO
CANDIDATES
1. SECTION-A is
COMPULSORY.
2. Attempt any FOUR
questions from SECTION-B.
3. Attempt any TWO
questions from SECTION-C.
4. Use of only P.S.G.
design data book is permitted.
5. Assume missing data
suitably, if any.
SECTION-A
(10
X 2 = 20 Marks)
1. (a) What are the
methods and materials used in manufacturing of crankshafts?
(b) What are the
applications of hauling chains?
(0) What is offset link of
roller chain?
((1) What is load
correction factor for flat-belt?
(e) What is belt rating?
(f) How is axial thrust in
helical gears overcome?
(g) What is crossed
helical gear?
(h) State any two
advantages of deep groove ball bearing.
(i) Why taper roller
bearings are used in a pair?
(1) What is thick film
lubrication?
SECTION-B
(4 X 5 = 20 Marks)
2. Discuss different types
of wear failure and breakage failure of gear tooth due to static and dynamic
loads.
3. Discuss advantages and
drawbacks of worm gear drives. Suggest materials for worm wheel and worm with
proper justification.
4. The load on the journal
bearing is 180 kN due to turbine shaft of 300 mm diameter running at 2000 rpm.
Determine the following:
(i)
Length of the
bearing if the allowable bearing pressure is 1.6 N/mmz, and
(ii)
Amount of heat to
be removed by the lubricant per minute if the bearing temperature is 60oC and
viscosity of the oil is 0.02 kg/m-s and the bearing clearance is 0.25 mm.
5. Give step-by step
procedure for the selection of flat belt from manufacturer's catalogue for
given application. Provide all other information and recommendations needed in
selection.
6. A pair of worm and worm
wheel is designated as 3/60/ 10/6. The worm is transmitting 5kW at 1440 rpm to
the worm wheel. The coefficient of friction is 0.1 and the normal pressure
angle is 200. Determine the lead angle, torque and component of gear tooth
forces acting on the worm and worm wheel.
SECTION-C
(2 X 10 = 20 Marks)
7. A pair of spur gears with 200 full-depth involute
teeth consists of a 20 teeth pinion meshing with 41 teeth gear. The module is 3
mm while the face width is 4omm. The material for the pinion as well as for the
gear is steel with an ultimate tensile strength of 600 N/mmz. The gears are
heat treated to a surface hardness of 400 BHN. The pinion rotates at 1450 rpm
and the surface factor for the application is 1.75. Assume the velocity factor
accounts for the dynamic load, and the factor of safety is 1.5. Determine wear
strength, effective load, torque, beam strength and rated power of gears.
Assume lewis form factor as 0.32 for 20 teeth.
8. A V-belt drive is required for a 15 kW, 1440 rpm
electric motor, which drives a centrifugal pump running at 360 rpm for a
service of 24 hours per day. From space considerations, the centre distance
should be approximately 1m. Determine
(a) Belt specifications
(b) number of belts
(c) correct centre distance, and
(d) pulley diameters
9. A concentric spring is used as valve spring in a
heavy duty diesel engine. It consists of two helical compression springs having
the same free length and same solid length. The composite spring is subjected
to a maximum force of 6000 N and the corresponding deflection is 50 mm. The
maximum torsional shear stress induced in each spring is 800 N/mmz. The spring index
of each spring is 6. Assume same material for two springs and the modulus of
rigidity of spring material is 81370 N/mm2. The diametrical clearance between
the coils is equal to the difference between their wire
diameters. Calculate:
(a) The axial force transmitted by each spring
(b) Wire and mean coil diameter of each spring
(c) Number of active coils in each spring
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