A 16000ME402062301 Pages: 3
Reg No.:_______________ Name:__________________________
APJ ABDUL KALAM TECHNOLOGICAL UNIVERSITY
B.Tech Degree S8 (S, FE) / S6 (PT) (S, FE) Examination June 2023 (2015 Scheme)
Course Code: ME402
Course Name: Design of Machine Elements-II
Use of Machine Design Data Book is permitted.
Max. Marks: 100 Duration: 3 Hours
PART A
Answer any two full questions, each carries 15 marks. Marks
1 a) A cone clutch having face angle of 12.50 is designed to transmit 200 N-m of (12)
torque at 1000 rpm. The larger diameter of the clutch is 300 mm, face width is 60
mm and coefficient of friction is 0.2. Determine (i) Axial force required to
transmit the torque, (ii) Axial force required to engage the clutch, (iii) Average
normal pressure when maximum torque is transmitted, (iv) Maximum and
minimum normal pressures.
b) What is the condition of self-locking in differential band brake? (3)
2 Select a single row deep groove ball bearing for a shaft of 75 mm diameter. The (15)
35 minutes operating cycle are as follows.
Radial load Thrust load Speed Duration
Load condition
(N) (N) (rpm) (min)
Static 11,500 - 720 09
Heavy shock 2,400 1,900 900 15
Moderate 10,000 1,500 1,440 11
shock
The bearing should be operated for 300 million of revolutions.
3 A 3600 hydrodynamic journal bearing operates at 1000 rpm and carries a load of 5 (15)
kN. The journal diameter is 50 mm, and the bearing length is 50 mm. The radial
clearance is 0.025 mm. The bearing is lubricated with SAE 30 oil and operating
temperature of oil is 800 C. Determine, (i) Bearing Pressure (ii) Sommerfeld
Number (iii) Minimum Film Thickness (iv) Coefficient of Friction using
McKee’s Equation (iv) Heat Generated.
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16000ME402062301
PART B
Answer any two full questions, each carries 15 marks.
4 Design a pair of spur gear to transmit a power of 20 kW at 1200 rpm. The teeth (15)
are of 200 full depth involute systems, having 20 teeth on pinion and a speed ratio
of 3:1.
5 Design a helical gear speed reducer having a rated power of 38 kW at 1500 rpm. (15)
The helix angle is 300 and pressure angle is 200. Both gears are made of same
material having maximum permissible stress of 56 MPa.. The speed reduction is
3:1. Specify the details of the drive.
6 Design a pair of bevel gears with 200 involute teeth, for a vertical drilling (15)
machine having a power of 50 kW at 720 rpm. The speed reduction is 4:1 and the
service factor may be taken as 1.35. Choose suitable material for the gear and
pinion.
PART C
Answer any two full questions, each carries 20 marks.
7 a) Select a V-belt drive for 15 kW, 1440 rpm motor, which drives a centrifugal (15)
pump running at a speed of 576 rpm for a service of 8-10 hours per day. The
distance between the driver and the driven shafts is approximately 1.2 m.
b) What are the advantages and disadvantages of V- belts compared with flat belts? (5)
8 a) A 15 kW, 960 rpm motor drives a line shaft at 300 rpm. The centre distance (14)
between the driver and the driven shafts is approximately 600 mm. The motor
shaft has a diameter of 50 mm. The starting torque on motor is 2 times the
running torque. The load is applied with moderate shocks. Select a suitable chain
drive.
b) With simple sketch explain the configuration of silent chain. What are the (6)
advantages and disadvantages of silent chain? Mention one application of silent
chain.
9 Design a connecting rod for an I C engine using the following data: (20)
Cylinder bore is 85 mm, length of connecting rod is 350 mm, max. gas pressure
is 3 MPa, Allowable unit stress for rod is 330 MPa, FOS against buckling
pressure is 5, Stroke length is 140 mm, mass of reciprocating parts is 1.5 kg,
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engine speed is 2000 rpm, thickness of bearing bush is 3 mm, l/d ratio are 1.5
and 1.25 for piston pin bearing and crank pin bearing respectively, allowable
bearing pressure for piston pin bearing is 13 MPa and the same for crank pin
bearing is 11 MPa, yield strength for cap material and bolt material are 380 MPa
and 450 MPa respectively, FOS for cap material and bolt material are 4 and 5
respectively, density of rod = 7800 kg/m3.
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