۸ 00042001 Pages: 2

Reg No.: Name:
APJ ABDUL KALAM TECHNOLOGICAL UNIVERSITY

Eighth semester B.Tech degree examinations, September 2020

Course Code: ME402
Course Name: Design of Machine Elements-II

Max. Marks: 100 Duration: 3 Hours
Use of design data book is permitted
Missing data may be suitably assumed

PARTA
Answer any two full questions, each carries 15 marks. Marks
1 a) Determine the main dimensions of a cone clutch faced with leather to (12)

transmit 30 kW at 750 rpm from an electric motor to an air compressor.
Assume an over load factor of 1.75. Due to possibility of contamination of
lining, a low value of coefficient of friction 0.2 is recommended.
b) What is the principle of operation of a centrifugal clutch? What are its (3)
applications?
2 a) A bearing is to carry a radial load of 240 kgf and a thrust load of 130 kgf. (12)
The load imposes light shock. The desired 90 % life is 10 hrs per day for 5
years at 3000 rpm. (a) Select a deep groove ball bearing. (b) What is the
probability of bearing surviving specified life?
b) What is Lio and 1.50 life of ball bearing? (3)
3 a) A journal bearing for ೩ steam turbine is required to support a radial load of (12)
270 kgf. The shaft diameter at the bearing is 60 mm. The speed of rotation is
1800 rpm. Design the bearing. Design should clearly indicate requirement of
artificial cooling.
b) Discuss the significance of bearing modulus in the design of journal bearing? (3)
PART B
Answer any two full questions, each carries 15 marks.
4 Design a helical gearing to transmit 60 HP. The pinion runs at 6000 rpm. (15)

The speed ratio is 3. Check also the gear pair for safe endurance strength and
surface durability based on the estimate of dynamic load from Buckingham’s
equation.

5 A pair of 20° full depth involute bevel gears is used to connect two shafts 9 (15)
right angles having a velocity ratio 2.5: 1. The gear is made from cast steel

and the pinion is from the forged steel. Pinion transmits 37.5 kW at 750 rpm.

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