Download GTU (Gujarat Technological University) BE/BTech (Bachelor of Engineering / Bachelor of Technology) 2019 Winter 7th Sem New 2170202 Automobile Component Design Previous Question Paper
Seat No.: ________ Enrolment No.___________
GUJARAT TECHNOLOGICAL UNIVERSITY
BE - SEMESTER ? VII (New) EXAMINATION ? WINTER 2019
Subject Code: 2170202 Date: 28/11/2019
Subject Name: Automobile Component Design
Time: 10:30 AM TO 01:30 PM Total Marks: 70
Instructions:
1. Attempt all questions.
2. Make suitable assumptions wherever necessary.
3. Figures to the right indicate full marks.
4. Use of data book is permitted.
MARKS
Q.1 (a) Explain how metal concentration can be avoided at junctions in a
casting?
03
(b) Discuss the design considerations for welding 04
(c) It is required to standardize load carrying capacities of dumpers in a
manufacturing unit. The minimum and maximum capacities of such
dumpers are 40 and 630kN respectively. The company is interested in
developing seven models in this range. Specify their load carrying
capacities.
07
Q.2 (a) What are the guidelines for selecting suitable lubricant for rolling contact
bearings?
03
(b) Why preloading is necessary in cylindrical roller bearing and how this is
achieved?
04
(c) A single row deep grove ball bearing is subjected to one-minute work
cycle that consist of following two parts. Refer Table 1 for radial and
axial factors.
Part 1 Part2
Duration(s) 15 45
Radial load(kN) 54 18
Axial load(kN) 15 7.5
Speed (r.p.m) 800 1600
Table1
The static and dynamic load capacities of the ball bearing are 60 and 88
kN respectively. Calculate the expected life of bearing in hours.
07
OR
(c) List down the assumptions on which Reynold?s equation for
hydrodynamic lubrication is derived.
07
Q.3 (a) Explain the following terminologies related with gear
i) module ii) circular pitch iii) pressure angle
03
(b) Which are the factors responsible for the introduction of dynamic forces
between two mating gear teeth and mention the methods to account for
it during gear design?
04
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1
Seat No.: ________ Enrolment No.___________
GUJARAT TECHNOLOGICAL UNIVERSITY
BE - SEMESTER ? VII (New) EXAMINATION ? WINTER 2019
Subject Code: 2170202 Date: 28/11/2019
Subject Name: Automobile Component Design
Time: 10:30 AM TO 01:30 PM Total Marks: 70
Instructions:
1. Attempt all questions.
2. Make suitable assumptions wherever necessary.
3. Figures to the right indicate full marks.
4. Use of data book is permitted.
MARKS
Q.1 (a) Explain how metal concentration can be avoided at junctions in a
casting?
03
(b) Discuss the design considerations for welding 04
(c) It is required to standardize load carrying capacities of dumpers in a
manufacturing unit. The minimum and maximum capacities of such
dumpers are 40 and 630kN respectively. The company is interested in
developing seven models in this range. Specify their load carrying
capacities.
07
Q.2 (a) What are the guidelines for selecting suitable lubricant for rolling contact
bearings?
03
(b) Why preloading is necessary in cylindrical roller bearing and how this is
achieved?
04
(c) A single row deep grove ball bearing is subjected to one-minute work
cycle that consist of following two parts. Refer Table 1 for radial and
axial factors.
Part 1 Part2
Duration(s) 15 45
Radial load(kN) 54 18
Axial load(kN) 15 7.5
Speed (r.p.m) 800 1600
Table1
The static and dynamic load capacities of the ball bearing are 60 and 88
kN respectively. Calculate the expected life of bearing in hours.
07
OR
(c) List down the assumptions on which Reynold?s equation for
hydrodynamic lubrication is derived.
07
Q.3 (a) Explain the following terminologies related with gear
i) module ii) circular pitch iii) pressure angle
03
(b) Which are the factors responsible for the introduction of dynamic forces
between two mating gear teeth and mention the methods to account for
it during gear design?
04
2
(c) A pair of spur gears consists of 24 teeth pinion rotating at 1000 rpm and
transmitting power to a 48 teeth gear. The module is 6mm, while the face
width is 60mm.Both the gears are made of steel with an ultimate tensile
strength of 450N/mm
2
.They are heat treated to a surface hardness of
250BHN.Assume the velocity factor to account for dynamic load.
Calculate
(i) Beam strength (ii) Wear strength (iii) The rated power that the gears
can transmit
Service factor =1.5, Factor of safety=2, Lewis form factor =0.337
07
OR
Q.3 (a) What are the objectives of providing backlash in a pair of gear teeth? 03
(b) Why involute profile is preferred for gear tooth? 04
(c) A helical pinion having 21 teeth to be made of plain carbon steel 55C8
(Sut =720N/mm
2
) is to mesh with a gear to be made of plain carbon steel
40C8 (Sut =580N/mm
2
). The gear pair is required to transmit 10kW
power from an electric motor running at 1000 rpm to a machine running
at 300 rpm. The starting torque of the motor is 125% of the rated torque.
The factor of safety required is 1.25. The face width is 10 times the
normal module and tooth system is 20? full depth involute. The helix
angle is 25.The gears are machined to meet the specifications of grade
6.The gear and pinion are to be case hardened to 300BHN and 350BHN
respectively. Design the gear by using the velocity factor and
Buckingham?s equation for dynamic load. The deformation factor ?C?
for gear pair is 11500N/mm
2
. Use the following formulae
Y=0.484-2.87/z? , Cv=5.6/(5.6+?v), K=0.16[BHN/100]
2
For grade 6, e = 8+0.63[mn+0.25?d],?m
07
Q.4 (a) A pair of bevel gears transmitting 10kW at 400 rpm. The pressure angle
is 20?. The diameter of pinion and gear are 150 and 200 mm respectively
and face width is 40mm. Determine the axial and radial component of
resultant gear tooth force.
03
(b) A worm gear pair is used to transmit power from an electric motor
running at 1500 rpm to the machine running at 60 rpm. The axial pitch
of the worm is 18.85mm, while the diametral quotient is 10. If the centre
distance is to be fixed at 180 mm, designate the gear pair.
04
(c) What are the design requirements for piston? 07
OR
Q.4 (a) What is meant by ?whipping stress? and how this is induced? 03
(b) Differentiate full-floating and semi floating type of connections between
piston pin and connecting rod.
04
(c) Determine the dimensions of cross-section of the connecting rod for a
diesel engine with the following data:
Cylinder bore=100mm
Length of connecting rod=350mm
Maximum gas pressure =4MPa
Factor of safety=6, Assume ?c=300N/mm
2
, a=1/7500
07
Q.5 (a) What are the advantages of using separate cylinder liners? 03
(b) List down the steps involved in the selection of rolling contact bearings
from manufacturers catalogue.
04
(c) Design an exhaust valve for a horizontal diesel engine using the
following data:
07
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1
Seat No.: ________ Enrolment No.___________
GUJARAT TECHNOLOGICAL UNIVERSITY
BE - SEMESTER ? VII (New) EXAMINATION ? WINTER 2019
Subject Code: 2170202 Date: 28/11/2019
Subject Name: Automobile Component Design
Time: 10:30 AM TO 01:30 PM Total Marks: 70
Instructions:
1. Attempt all questions.
2. Make suitable assumptions wherever necessary.
3. Figures to the right indicate full marks.
4. Use of data book is permitted.
MARKS
Q.1 (a) Explain how metal concentration can be avoided at junctions in a
casting?
03
(b) Discuss the design considerations for welding 04
(c) It is required to standardize load carrying capacities of dumpers in a
manufacturing unit. The minimum and maximum capacities of such
dumpers are 40 and 630kN respectively. The company is interested in
developing seven models in this range. Specify their load carrying
capacities.
07
Q.2 (a) What are the guidelines for selecting suitable lubricant for rolling contact
bearings?
03
(b) Why preloading is necessary in cylindrical roller bearing and how this is
achieved?
04
(c) A single row deep grove ball bearing is subjected to one-minute work
cycle that consist of following two parts. Refer Table 1 for radial and
axial factors.
Part 1 Part2
Duration(s) 15 45
Radial load(kN) 54 18
Axial load(kN) 15 7.5
Speed (r.p.m) 800 1600
Table1
The static and dynamic load capacities of the ball bearing are 60 and 88
kN respectively. Calculate the expected life of bearing in hours.
07
OR
(c) List down the assumptions on which Reynold?s equation for
hydrodynamic lubrication is derived.
07
Q.3 (a) Explain the following terminologies related with gear
i) module ii) circular pitch iii) pressure angle
03
(b) Which are the factors responsible for the introduction of dynamic forces
between two mating gear teeth and mention the methods to account for
it during gear design?
04
2
(c) A pair of spur gears consists of 24 teeth pinion rotating at 1000 rpm and
transmitting power to a 48 teeth gear. The module is 6mm, while the face
width is 60mm.Both the gears are made of steel with an ultimate tensile
strength of 450N/mm
2
.They are heat treated to a surface hardness of
250BHN.Assume the velocity factor to account for dynamic load.
Calculate
(i) Beam strength (ii) Wear strength (iii) The rated power that the gears
can transmit
Service factor =1.5, Factor of safety=2, Lewis form factor =0.337
07
OR
Q.3 (a) What are the objectives of providing backlash in a pair of gear teeth? 03
(b) Why involute profile is preferred for gear tooth? 04
(c) A helical pinion having 21 teeth to be made of plain carbon steel 55C8
(Sut =720N/mm
2
) is to mesh with a gear to be made of plain carbon steel
40C8 (Sut =580N/mm
2
). The gear pair is required to transmit 10kW
power from an electric motor running at 1000 rpm to a machine running
at 300 rpm. The starting torque of the motor is 125% of the rated torque.
The factor of safety required is 1.25. The face width is 10 times the
normal module and tooth system is 20? full depth involute. The helix
angle is 25.The gears are machined to meet the specifications of grade
6.The gear and pinion are to be case hardened to 300BHN and 350BHN
respectively. Design the gear by using the velocity factor and
Buckingham?s equation for dynamic load. The deformation factor ?C?
for gear pair is 11500N/mm
2
. Use the following formulae
Y=0.484-2.87/z? , Cv=5.6/(5.6+?v), K=0.16[BHN/100]
2
For grade 6, e = 8+0.63[mn+0.25?d],?m
07
Q.4 (a) A pair of bevel gears transmitting 10kW at 400 rpm. The pressure angle
is 20?. The diameter of pinion and gear are 150 and 200 mm respectively
and face width is 40mm. Determine the axial and radial component of
resultant gear tooth force.
03
(b) A worm gear pair is used to transmit power from an electric motor
running at 1500 rpm to the machine running at 60 rpm. The axial pitch
of the worm is 18.85mm, while the diametral quotient is 10. If the centre
distance is to be fixed at 180 mm, designate the gear pair.
04
(c) What are the design requirements for piston? 07
OR
Q.4 (a) What is meant by ?whipping stress? and how this is induced? 03
(b) Differentiate full-floating and semi floating type of connections between
piston pin and connecting rod.
04
(c) Determine the dimensions of cross-section of the connecting rod for a
diesel engine with the following data:
Cylinder bore=100mm
Length of connecting rod=350mm
Maximum gas pressure =4MPa
Factor of safety=6, Assume ?c=300N/mm
2
, a=1/7500
07
Q.5 (a) What are the advantages of using separate cylinder liners? 03
(b) List down the steps involved in the selection of rolling contact bearings
from manufacturers catalogue.
04
(c) Design an exhaust valve for a horizontal diesel engine using the
following data:
07
3
Cylinder bore=150mm, Length of stroke=275mm, Engine speed=500
rpm, Maximum gas pressure=3.5MPa, Seat angle=45?, Mean
velocity=50m/s, w=(0.05 to 0.07)dp, k=0.42, ?b=50N/mm
2
Calculate:
(i) diameter of the valve port, (ii) diameter of valve head, (iii) thickness
of valve head, (iv) diameter of valve stem and (v) maximum lift of the
valve.
OR
Q.5 (a) What are the purposes of gearbox? 03
(b) Explain the following terminologies related with big end bearings of
connecting rod
(i)Crush (ii) Shim
04
(c) The following data is given for the cap and bolts of the big end of
connecting rod.
Engine speed=1800 rpm, Length of connecting rod=350mm
Length of stroke=175mm, Mass of reciprocating parts=2.5kg
Length of crank pin=76mm, Diameter of crank pin=58mm
Thickness of bearing bush=3mm
Permissible tensile stress for bolts=60N/mm
2
Permissible bending stress for cap=80N/mm
2
Calculate the nominal diameter of bolts and thickness of cap for the big
end.
07
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This post was last modified on 20 February 2020