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INFANT JESUS COLLEGE OF ENGINEERING

B.E. MECHANICAL ENGINEERING Semester VI

ME1352 DESIGN OF TRANSMISSION SYSTEM

Duration : 3 Hours Max: 100 Marks

Use of Approved Data Book is PermittedPART A 10 X 2 = 20 marks

Answer ALL questions

1 What is Zero film bearing?

2 Enumerate the relative merits of V belts when compared with flat belt drives.

3 Define Diametral pitch of a spur gear

4 How a helical gear differs from spur gear?

5 What is Miter Gear?

6 In which condition of shafting, worm gears are used, and What is major failure for

worm gear drive?

7 What do you understand by preferred numbers?8 What does the ray diagram of the gear box indicates?

9 List out the factors to be considered while designing a friction clutch.

10 Enumerate the desirable characteristics of brake lining material

Part B 5 *16 = 80 marks

11 Design a journal bearing for a centrifugal pump to the following specifications.

Journal diameter = 75 mm.

Speed of the journal = 1440 rpm.

Load on each journal = 11.5 KN OR

12 Design a V belt drive for the following dimensions.

Driving pulley diameter : 500 mm

Driven pulley diameter : 150 mm

Speed of driving pulley : 300 rpm

Center distance : 925 mm

Power to be transmitted : 7.5 kW.

13 Design a straight spur gear drive for transmitting a power of 8 kW with a pinion speed

of 764 rpm. Speed ratio is 2. The gears are to be made of C45 steel. Life is to be 10,000

hours.

OR

14 Design a bevel gear drive to transmit 7.35 KW at 1440 rpm for the following data.

Gear ratio = 3, Life = 10000 hrs, Material for pinion and gear is C45 steel. Helix angle

150

15 Design a bevel gear drive to transmit 3.5 kW. Speed ratio = 4. Driving shaft speed is200 rpm. The drive is non reversible. The pinion is made of Steel whereas wheel is of

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CI. Assume a life of 25,000 hrs.

OR

16 Design a worm gear drive to transmit 20 KW at 1440 rpm. The speed of worm wheel

is 60 rpm. The worm and wheel are made up of steel, bronze respectively. Select the

number of starts as 3.

17 The spindle of a pillar drill is to run at 12 different speeds in the range of 100 rpm and

355 rpm. Design a three stage gear box with a standard step ratio. Sketch the layout of

the gear box, indicating the number of teeth on each gear. The gear box receives 5 kW

from an electric motor running at 360 rpm. Sketch also the speed diagram.

OR

18 Draw the kinematic diagram and speed diagram of the gear box in a head stock of a

lathe having 9 spindle speeds ranging from 31.5 rpm to 1050 rpm. Calculate the

number of teeth on all gears if the minimum number of teeth is 25. Also calculate the

% of deviation in speeds.

19 A leather faced conical clutch has cone angle of 30 0. The pressure between the contact

surface is limited to 0.35 N/mm2 and the breadth of the conical surface is not to exceed

1/3rd of the mean radius. Determine the dimensions of the contact surface to transmit 22

kW at 2000 rpm. Also calculate the force required to engage the clutch. Take the

coefficient of friction as 0.15.

OR

20 A differential band brake is to be used for a winch lifting a load of 45 kN through a

rope wound around a barrel of 500 mm in diameter. The brake drum to be keyed to the

same shaft is to be 600 mm in diameter and the angle of lap of the brake band over the

drum is 2500 approximately. Determine the width and thickness of the band. Operating

arms of the brake are 40 mm and 200 mm and the operating lever is 1.5 m long.

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