ME6601 – DESIGN OF TRANSMISSION SYSTEMS

ANNA UNIVERSITY QUESTIONS

(UNIT WISE MATERIAL)

PREPARED BY

Prof.Mr.J.BHARANICHANDAR M.Tech.,

Prof.Mr.P.KARTHIKEYAN M.Tech.,

Prof.Mr.A.MOHAN M.E.,

DEPARTMENT OF MECHANICAL ENGINEERING

VELTECH-AVADI-CHENNAI-62

UNIT 1 DESIGN OF FLEXIBLE ELEMENTS

FLAT BELT DRIVE

1

Select a high speed duck flat belt drive for a fan running at 360 rpm which is

driven by 10 KW, 1440 rpm motor. The belt drive is open type and space

available for a center distance of 2 m approximately. The diameter of the

driven pulley is 1000 rpm.

NOV/DEC 2018

2

Select a flat belt to drive a mill at 250 rpm from a 10KW, 730 rpm motor.

Centre distance is to be around 2000 mm. the mill shaft pulley is of 1000

mm diameter.

MAY/JUN 2018

3

Design a flat belt drive to transmit 110 kW for a system consisting of two

pulleys of diameters 0.9 m and 1.2 m respectively, for a centre distance of

3.6 m, belt speed of 20 m/s and co efficient of friction=0.3. There is a slip of

1.2% at each pulley and 5% friction loss at each shaft with 20% over load.

NOV/DEC 2016

4

Design a flat belt drive to transmit 110 kW for a system consisting of two

pulleys of diameters 0.9 m and 1.2 m respectively, for a centre distance of

3.6 m, belt speed of 20 m/s and co efficient of friction=0.3. There is a slip of

1.2% at each pulley and 5% friction loss at each shaft with 20% over load.

MAY/JUN 2016

5

A compressor is to run by a motor pulley running at 1440 rpm, speed ratio

2.5. Choose a flat belt crossed drive. Center distance between pulleys is 3.6

m. Take belt speed as 16 m/s. Load factor is 1.3. Take a 5-ply, flat Dunlop

belt. Power to be transmitted is 12 kW. High speed load rating is 0.0118

kW/ply/mm width at V=5 m/s. Determine the width and length of the belt

NOV/DEC 2014

6

A belt is to transmit 25 kW at 720 rpm to a rolling machine with a speed

ratio of 3. Center distance between the pulleys is 2.8 m. Design a suitable

belt drive if the rolling machine pulley diameter is 0.9m.

NOV/DEC 2012

7

A flat belt drive is to design to drive a flour mill. The driving power

requirement of the mill is 22.5 kW at 750 rpm with a speed reduction of 3.

The distance between the shafts is 3 m. Diameter of the mill pulley is 1.2 m.

Design and make a neat sketch of the drive.

MAY/JUN 2012

8

Design a flat belt drive for the following data: Power to be transmitted =22.5

kW; driver speed =740 rpm; speed ratio=3; distance between the

pulleys=3m;larger pulley diameter=1.2m

NOV/DEC 2011

9

Select a flat belt to drive a mill at 250 rpm from a 10 kW, 7330 rpm motor.

Centre distance is to be around 2 m. The mill shaft pulley is of 1 m

diameter.

APR/MAY 2011

V BELT DRIVE

1

A centrifugal pump running at 340 rpm is to be driven by a 100 KW motor

running at 1440 rpm. The light duty drive is to work for at least 20 hours

every day. The center distance between the motor shaft and the pump shaft

is 1200 mm. suggest a suitable multiple v belt drive for this application.

NOV/DEC 2018

2

Select a V-belt drive for 15 KW, 1440 rpm motor, which drives a

centrifugal 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 shaft is

APR/MAY 2018

approximately 1.2 m. service factor, Ks = 1.1, design factor Na = 1.0, VR =

2.5.

3

Design a V-belt drive to the following specifications: Power to be

transmitted 75 kW, Speed of driving wheel is 1440 rpm, Speed of driven

wheel is 400 rpm, Diameter of driving wheel is 300 mm, Center distance is

2500 mm, and Service is 16 hours/day.

NOV/DEC 2017

4

Two shafts whose centres are 1 m apart are connected by a V-belt drive. The

driving pulley is supplied with 100 kW and has an effective diameter of 300

mm. It runs at 1000 rpm, while the driven pulley runs at 375 rpm. The angle

of groove on the pulley is 40˚. The permissible tension in 400 mm2 cross

sectional area of belt is 1100 kg/m3. Taking µ=0.28, estimate the number of

belts required. Also calculate the length of the each belt.

APR/MAY 2017

5

Select a suitable V-belt and design the drive for a wet grinder. Power is

available from a 0.5 kW motor running at 750 rpm. Drum speed is to be

about 100 rpm. Drive is to be compact.

NOV/DEC 2015

6

Design a V-belt drive and calculate the actual belt tensions and average

stress for the following data. Power to be transmitted=7.5 kW, speed of

driving wheel=1000 rpm, speed of driven wheel=300 rpm, diameter of

driven pulley=500 mm, diameter of driver pulley=150 mm and center

distance=925 mm

APR/MAY 2015

7

A V-belt drive is to transmit 45 kW in a heavy saw mill which works in two

shifts of 8 hours each. The speed of motor shaft is 1400 rpm with the

approximate speed reduction of 3 in the machine shaft. Design the drive and

calculate the average stress induced in the belt.

MAY/JUN 2014

8

A centrifugal pump running at 340 rpm is to be driven by a 100 kW motor

running at 1440 rpm. The drive is to work for at least 20 hours every day.

The centre distance between motor shaft and pump shaft is 2000 mm.

Suggest a suitable multiple V-belt drive for this application. Also calculate

the actual belt tensions and stress induced.

NOV/DEC 2013

9

Design a V-belt drive to the following specifications: Power to be

transmitted 75 kW, Speed of driving wheel is 1440 rpm, Speed of driven

wheel is 400 rpm, Diameter of driving wheel is 300 mm, Center distance is

2500 mm, and Service is 16 hours/day.

MAY/JUN 2013

10

Select a suitable V-belt and design the drive for a wet grinder. Power is

available from a 0.5 kW motor running at 750 rpm. Drum speed is to be

about 100 rpm. Drive is to be compact.

MAY/JUN 2011

CHAIN DRIVE

1

The transporter of a heat treatment furnace is driven by a 4.5 KW, 1440 rpm

induction motor through a chain drive with a speed reduction ratio of 2.4.

the transmission is horizontal with bath type of lubrication. Rating is

continuous with 3 shifts per day. Design the complete chain drive. Assume

center distance as 500 mm and service factor as 1.5

NOV/DEC 2018

2

Design a chain drive to actuate a compressor from a 10 KW electric motor

at 960 rpm. The compressor speed is to be 350 rpm. Minimum centre

distance should be 500 mm. motor is mounted on an auxiliary bed.

Compressor is to work for 8 hours/day.

MAY/JUN 2018

3

A truck equipped with a 9.5 kW engine uses a roller chain as the final drive

to the rear axle. The driving sprocket runs at 900 rpm and the driven

sprocket at 400 rpm with a centre distance of approximately 600 mm. Select

the roller chain. Number of teeth on drilling sprocket can be taken as 27 and

the pitch value can be taken at the middle of Pmax and Pmin values.

APR/MAY 2017

4

A bucket elevator is to be driven by geared motor and a roller chain drive

with the information given below: Motor output=30 kW, Speed of motor

shaft=100 rpm, Elevator drive shaft speed=42 rpm, Load=even, Distance

between centers of sprocket approximately=1.2 m, Period of operation=16

hours/day. Geared motor is mounted on an auxiliary bed for centre distance

adjustments. Design the chain drive.

NOV/DEC 2016

5

A 7.5 kW electric motor running at 1400 rpm is used to drive the input shaft

of the gearbox of a machine. Design a suitable roller chain to connect the

motor shaft to the gear box shaft to give an exact speed ratio of 10:1. The

centre to centre distance of the shaft is to be approximately 600 mm

MAY/JUN 2016

6

A 7.5 kW electric motor running at 1400 rpm is used to drive the input shaft

of the gearbox of a machine. Design a suitable roller chain to connect the

motor shaft to the gear box shaft to give an exact speed ratio of 10:1. The

centre to centre distance of the shaft is to be approximately 600 mm

APR/MAY 2015

7

Design a chain drive to actuate a compressor from a 15 kW electric motor

running at 1000 rpm, The compressor speed being 350 rpm. The minimum

centre distance is 500 mm. The compressor operates 15 hours/day. The

chain tension may be adjusted by shifting the motor.

MAY/JUN 2014

8

The transporter of a heat treatment furnace is driven by a 4.5 kW, 1440 rpm

induction motor through a chain drive with a speed reduction ratio of 2.4.

The transmission is horizontal with bath type of lubrication. Rating is

continuous with 3 shifts per day/ Design the complete chain drive.

NOV/DEC 2013

9

Design a chain drive to actuate a compressor from a 10 kW electric motor at

960 rpm. The compressor speed is to be 350 rpm. Minimum centre distance

should be 0.5 m. Compressor is to work for 8 hours/day.

MAY/JUN 2013

10

Select a suitable chain to transmit 15 kW at 1000 rpm of a sprocket pinion.

Speed reduction is 2.5:1. Driving motor is mounted on an adjustable base.

Assume that load is steady, drive is horizontal and service is 12h hours/day.

NOV/DEC 2012

11

Design a chain drive to drive a centrifugal compressor from an electric

motor 15 kW at 1000 rpm. The speed reduction ratio is 2.5. The compressor

to work for 16 hours a day. State solutions for common problems

encountered in continuous operation of the drive.

MAY/JUN 2012

12

A truck equipped with a 9.5 kW engine uses a roller chain as the final drive

to the rear axle. The driving sprocket runs at 900 rpm and the driven

sprocket at 400 rpm with a centre distance of approximately 600 mm. Select

the roller chain.

APR/MAY 2011

WIRE ROPE DRIVE

1

A workshop crane is lifting a load of 25 KN through a wire rope and hook.

The weight of the hook etc., is 15 KN. The rope drum diameter may be

taken as 30 times the diameter of the rope. The load is to be lifted with an

NOV/DEC 2018

acceleration of 1m/s2. Calculate the diameter of the wire rope. Take a factor

of safety of 6 and E for the wire is 80 KN/mm2. The ultimate stress may be

taken as 1800MPa. The cross sectional area of the wire rope may be taken

as 0.38 times the square of the wire rope diameter.

2

A temporary elevator is assembled at the construction site to raise building

materials, such as cement, to a height of 20 m. it is estimated that the

maximum weight of the material to be raised is 5 KN. It is observed that the

acceleration in such applications is 1m/s2, 10 mm diameter, 6x19

construction wire ropes with fibre core are used for this application. The

tensile designation of the wire is 1570 and the factor of safety should be 10

for preliminary calculations. Determine the number of wire ropes required

for this application. Neglect bending stresses.

APR/MAY 2018

3 Select a wire rope for a vertical mine hoist to lift a load of 20 kN from a

depth of 500 meters. A rope speed of 3 m/s is to be attained in 10 s. NOV/DEC 2017

4 Select a wire rope for a vertical mine hoist to lift a load of 20 kN from a

depth of 60 meters. A rope speed of 4 m/s is to be attained in 10 s. NOV/DEC 2015

5

At the construction site, 1 tonne of steel is to be lifted up to a height of 20 m

with the help of 2 wire ropes 6x19 size, nominal diameter 12 mm and

braking load 78 kN Determine the factor of safety if the sheave diameter is

56 d and wire rope is suddenly stopped in 1 seconds when travelling at a

speed of 1.2 m/s. What is the factor safety if the bending load is neglected?

NOV/DEC 2014

6

A workshop crane carries a load of 30 kN using wire ropes and a hook. The

hook weighs 15 kN Diameter of the rope drum is 30 times the diameter of

the rope. The load is lifted with an acceleration of 1 m/s2. Find the diameter

of the rope. FS=6, Er=80 kN/mm2, σu=180 kN/mm2, cross section of the

rope=0.4x(dia of rope)2

NOV/DEC 2011

TWO MARKS

1 Name the four types of belts used for transmission of power. NOV/DEC 2018

2 When do you use stepped pulley drive. NOV/DEC 2018

3 Define co-efficient of friction. APR/MAY 2018

4 What are the advantages of chain drives. APR/MAY 2018

5 Write the advantages of V belts over flat belts NOV/DEC 2017

6 List the chain drive failures NOV/DEC 2017

7 A longer belt will last more than a shorter belt. Why? APR/MAY 2017

8 List the advantages of wire ropes compared to chains. APR/MAY 2017

9 Define the term “crowning of pulley”. NOV/DEC 2016

10 What factors will affect the working conditions of the chain drive? NOV/DEC 2016

11 Name the few materials of belt drives. MAY/JUN 2016

12 Under what circumstances, chain drives are preferred over V-belt drives? MAY/JUN 2016

13 What is centrifugal effect on belts? NOV/DEC 2015

14 What is chordal action in chain drives? NOV/DEC 2015

15 In what ways the timing belts are superior to ordinary V-belts APR/MAY 2015

16 What is meant by ‘Chordal action of chain’? Also name a company that

produces driving chains. APR/MAY 2015

17 What do you understand by 6 x 19 constructions in wire ropes? NOV/DEC 2014

18 Mention the losses in belt drive. NOV/DEC 2014

19 What are the factors upon which the co efficient of friction between the belt

and pulley depends? MAY/JUN 2014

20 Brief the term “crowning of pulley”. MAY/JUN 2014

21 What is meant by ply of belt? NOV/DEC 2013

22 Write any four wire rope applications. NOV/DEC 2013

23 What are the materials used for belt-drive? MAY/JUN 2013

24 Why slip is less in the case of V-belts when compared with flat belts? MAY/JUN 2013

25 How is wire rope specified? Give an example. NOV/DEC 2012

26 Mention the parts of roller chain. NOV/DEC 2012

27 How is V-belt specified? APR/MAY 2012

28 Give the advantages of chain drives over belt drives. APR/MAY 2012

29 Mention the materials used for making belts. NOV/DEC 2011

30 Specify the five parts of roller chain. NOV/DEC 2011

31 Distinguish between open belt drive and cross belt drive. Which is better? APR/MAY 2011

32 Give any three applications of chain drives. What are their limitations? APR/MAY 2011

33 In what way silent chain is better than the ordinary chain? MAY/JUN 2011

34 Give the condition for maximum power transmission in terms of centrifugal

tension in case of belt drive. MAY/JUN 2011

UNIT-2

SPUR GEARS AND PARALLEL AXIS HELICAL GEARS

1

A compressor running at 300 rpm is driven by a 15 KW, 1200 rpm motor

through a 14½° full depth spur gears. The center distance is 375 mm. The

motor pinion is to be of C30 forged steel hardened (BHN 250) and tempered,

and the driven gear is to be of cast iron. Assuming medium shock condition

and minimum number of teeth as 18, design the gear drive completely.

NOV/DEC 2018

2

Design a pair of spur gears to transmit 20 KW at a pinion speed of 1400 rpm.

The transmission ratio is 4. Assume 15Ni 2Cr 1 Mo 15 for pinion and C45 for

gear.

APR/MAY 2018

3

Design a pair of spur gears to transmit 20 kW at a pinion speed of 1400 rpm.

The transmission ratio is 4.Pinion and gears are made of 15Ni2Cr1Mo15 and

C45 steels respectively. Assume pressure angle 20° and minimum no of teeth

20.

NOV/DEC 2017

4

Design a spur gear drive required to transmit 45 kW at a pinion speed of 800

rpm. The velocity ratio is 3.5:1. The teeth are 20° full depth involute with 18

teeth on pinion. Both the pinion and gear are accurately hobbed and made of

steel with a safe static stress of 180 N/mm² Assume medium shock conditions

Vm=12m/s and steel is hardened to 200 BHN

APR/MAY 2017

5

Design a pair of straight spur gear drive for a stone crusher, the pinion and

wheel are made of C 15 steel and cast iron grade 30 respectively. The pinion is

to transmit 22 kW power at 900 rpm. The gear ratio is 2.5. Take pressure angle

of 20° and working life of gears as 10000 hours.

NOV/DEC 2016

6 A Speed reducing unit using spur gear is to be designed. Power to be

transmitted is 60 hp and is continuous with moderate shaft loads. The speeds of

the 720 rpm and 144 rpm, respectively. The center distance is kept as small as

possible. Select a suitable material and design the gears. Give the details of the

gears.

APR/MAY 2016

7

Design a spur gear drive required to transmit 45 kW at a pinion speed of 800

rpm. The velocity ratio is 3.5:1. The teeth are 20° full depth involute with 18

teeth on pinion. Both the pinion and gear are accurately hobbed and made of

steel with a safe static stress of 180 N/mm² Assume medium shock conditions

NOV/DEC 2015

8

Design a spur gear drive to transmit 8 kW at 720 rpm and the speed ratio is 2.

The pinion and wheel are made of the same surface hardened carbon steel with

55 RC and core hardness less than 350 BHN. Ultimate strength is 720 N/mm2

and yield strength is 360 N/mm2

APR/MAY 2015

9

Design a spur gear drive for a stone crusher where the gears ore made of C40

steel. The pinion is transmitting 30 kW at 1200 rpm. The gear ratio is 3. Take

the working life of gears as 7500 hours.

NOV/DEC 2014

10

Design and draw spur gear drive transmitting 30 kW at 400 rpm to another

shaft running at 1000 rpm. The load is steady and continuous. The material for

the pinion is cast steel and for the gear is cast iron. Take module as 10 mm.

Also check the design for dynamic load and wear.

MAY/JUNE

2014

11

Design a pair of spur gears to transmit 22.5 kW at 900 rpm. Speed reduction is

2.5. Materials for pinion and wheel are C15 steel and cast iron grade 30

respectively. Take pressure angle of 20˚ and working life of gears 10,000 hrs.

NOV/DEC 2013

12

Design a straight spur gear drive. Transmitted power 8 kW. Pinion speed 764

rpm. Speed ratio is 2. The gears are to be made of C45 steel. Life of gear is

10000 hrs.

MAY/JUNE

2013

13

Design a spur gear drive to transmit 10 kW at 1440 rpm, speed reduction is 3.

Take pressure angle is 20° and working life of gears as 15,000 hrs. Assume the

materials for pinion and wheel as heat treated cast steel and high grade cast

iron respectively.

NOV/DEC 2012

14

Design a spur gear drive for a heavy machine tool with moderate shocks. The

pinion is transmitting 18 kW at 1200 rpm with a gear ratio of 3.5. Design the

drive and check for elastic stresses and plastic deformation. Make a sketch and

label important dimensions arrived.

MAY/JUNE

2012

15

A motor shaft rotating at 1500 rpm has to transmit 15 kW to a low speed shaft

with a speed reduction of 3:1. The teeth are 20° involute with 25 teeth on the

pinion. Both the pinion and gear are made of steel with maximum safe stress of

200 N/mm2. A safe stress of 40 N/mm2 may be taken for the shaft on which the

gear is mounted and also for the key. Design a spur gear drive to suit the above

conditions. Assume starting torque to be 25% higher than the running torque.

NOV/DEC 2011

16

In a spur gear drive for a stone crusher, the gears are made of C40 steel. The

pinion is transmitting 20 kW at 1200 rpm. The gear ratio is 3. Gear is to work 8

hrs per day, 6 days a week and for 3 years. Design the drive.

APR/MAY 2011

17 Design a pair of spur gears to transmit 30 kW at a pinion speed of 1400 rpm.

The transmission ratio is 4.Assume suitable material.

MAY/JUNE

2011

HELICAL GEAR

1

Design a carefully cut helical gear to transmit 15 KW at 1400 rpm to the following

specifications. Speed reduction is 3. Pressure angle is 20°, helix angle is 15°. The

material for both the gears is C45 steel. Allowable static stress is 180 N/mm2, surface

endurance limit 800 N/mm2. Young’s modulus of the material = 2x105 N/mm2. Assume

minimum number of teeth as 20 and medium shock conditions, v = 15 m/s.

NOV/DEC 2018

2

Design a helical gear drive to transmit the power of 15 KW. Speed ratio 6, pinion speed

1200 rpm, helix angle is 25°. Select 15Ni 2Cr 1 Mo 15 for pinion and C45 for gear and

design the gear pair.

APR/MAY 2018

3

Design a pair of helical gear to transmit 10 kW at 1000 rpm of the pinion. Speed ratio 5.Take

40Ni2Cr1Mo28 steel as material for pinion and gear.

Assume minimum no of teeth as 20 and tabulate the result.

NOV/DEC 2017

4

For intermittent duty of an elevator, two cylindrical gears made of alloy

steel 40Ni2Cr1Mo28 and have to transmit 12.5 kW at a pinion speed of 1200 rpm.

Design the gear pair for the following specification: Gear ratio 3.5, pressure angle 20°,

in volute full depth, helix angle 15°. Gears are expected to work 6 hours a day for 10

years. Minimum no of teeth on pinion can be taken as 20 and IS quality 8.

APR/MAY 2017

5

Design a pair of helical gear to transmit 10 kW at 1000 rpm of the pinion. Reduction ratio of

5 is required. Pressure angle is 20° and the helix angle is 15°. The materials for both gears are

40Ni2Cr1Mo28. Give the details of the drive in a tabular form.

NOV/DEC 2016

6

A pair of helical gears subjected to moderate shock loading is to transmit 30 kW at 1500

rpm of the pinion. The speed reduction ratio is 4 and the helix angle is 20°. The service

is continuous and the teeth are 20° FD in the normal plane. For gear life of 10000 hours,

design the gear drive.

APR/MAY 2016

7 Design a pair of helical gear to transmit 10 kW pinion speed of 1000 rpm. The reduction

ratio is 5. Assume suitable materials and stresses. NOV/DEC 2015

8 Design a helical gear drive to transmit the power of 14.7 kW. Speed ratio 6, pinion

speed 1200 rpm, helix angle is 25°, select suitable materials and design the gear. APR/MAY 2015

9

Design a helical gear drive to connect an electric motor to a reciprocating pump. Gears

are overhanging in their shafts. Motor speed =1440 rpm. Speed reduction ratio= 5,

motor power=37 kW, pressure angle=20°, helix angle =25°

NOV/DEC 2014

10

A single stage helical gear reducer is to receive power from a 1440 rpm, 25 kW

inductions motor. The gear tooth profile is involute full depth with 20˚ normal pressure

angle. The helix angle is 23˚, no of teeth on pinion is 20 and the gear ratio is 3. Both

the gears are made of steel with allowable beam stress of 90 MPa and hardness 250

BHN. Design the gears for 20% overload carrying capacity from the standpoint of

bending strength and wear and if the incremental dynamic load of 8 kN is estimated in

tangential plane, what will be the safe power transmitted by the pair at the same speed.

MAY/JUNE 2014

11

Design a helical gear to transmit 15 kW at 1440 rpm to the following specifications:

Speed reduction is 3, pressure angle is 20˚, helix angle is 15˚, and the material of both

gears is C45 steel. Allowable static stress 180 GPa, surface endurance limit is 800 GPa.

Young’s modulus of material 200 GPa.

NOV/DEC 2013

12 Design a pair of helical gear to transmit 10 kW at 1000 rpm of the pinion. Reduction

ratio of 5 is required. Give details of the drive in a tabular form. MAY/JUNE 2013

13 Deduce the expressions for forces acting on a gear tooth of helical gear with the aid of

a schematic diagram. NOV/DEC 2012

14

Design a pair of helical gear to transmit 37.5 kW at 1750 rpm of the pinion. The drive

is subjected to heavy shock loading. The speed reduction ratio is 4 and the helix angle is

15°. Select suitable material and design the gears. Check for working stresses and sketch

the drive.

MAY/JUNE 2012

15

A general purpose enclosed gear train is based on parallel helical gears, specified life

is 36,000 hrs. Torque at driven shaft is 411 Nm. Driving shaft speed is 475 rpm.

Velocity ratio is 4. It is desired to have standard centre distance. Design the gear drive.

NOV/DEC 2011

16 Design a pair of helical gear to transmit 10 kW at 1000 rpm of the pinion. Reduction ratio of

5 is required APR/MAY 2011

17 Design a pair of helical gears to transmit 20 kW power at 1000 rpm of the pinion and

reduction ratio of 5. MAY/JUNE 2011

TWO MARKS

1 State the advantages of toothed gears over the other types of transmission systems. NOV/DEC 2018

2 Why pinion is made harder than gear. NOV/DEC 2018

3 Specify the types of gear failures. APR/MAY 2018

4 In what ways helical gears are different from spur gears. APR/MAY 2018

5 What is meant by stub tooth in gear drives? NOV/DEC 2017

6 Define virtual no of teeth in helical gears. NOV/DEC 2017

7 What are the effects of increasing or decreasing the pressure angle in gear design? APR/MAY 2017

8 Differentiate double-helical and herringbone gears. APR/MAY 2017

9 Define backlash. What factor influence backlash? NOV/DEC 2016

10 A helical gear has a normal pressure angle of 20°, a helix angle of 45°, normal

module of 4 mm and has 20 teeth. Find the pitch diameter. NOV/DEC 2016

11 What are the profiles of spur gear? MAY/JUN 2016

12 What is herringbone gear? MAY/JUN 2016

13 Define module. NOV/DEC 2015

14 Differentiate double-helical and herringbone gears. NOV/DEC 2015

15 State law of gearing. APR/MAY 2015

16 What is pressure angle? What is the effect of increase in pressure angle? APR/MAY 2015

17 Specify the effects of increasing the pressure angle in gear design. NOV/DEC 2014

18 Why is gear tooth subjected to dynamic load? NOV/DEC 2014

19 What is pressure angle? What is the effect of increase in pressure angle? MAY/JUN 2014

20 What condition must be satisfied in order that a pair of spur gears may have a constant

velocity ratio?

MAY/JUN 2014

21 Difference between circular pitch and diametral pitch. NOV/DEC 2013

22 Where do we use spiral gears? NOV/DEC 2013

23 Define module. MAY/JUN 2013

24 What are the main types of gear tooth failure? MAY/JUN 2013

25 Why is pinion made harder than the gear? NOV/DEC 2012

26 Compare the features of spur and helical gears. NOV/DEC 2012

27 What are the generally used gear profiles? MAY/JUN 2012

28 Specify the significance of minimum number of teeth in pinions. MAY/JUN 2012

29 Mention the advantages of non-metallic gears. NOV/DEC 2011

30 How does failure by pitting happen in gears? NOV/DEC 2011

31 Define module. APR/MAY 2011

32 What are the common forms of gear tooth profile? APR/MAY 2011

33 Mention few gear materials. MAY/JUN 2011

34 Why is a gear tooth subjected to dynamic loading? MAY/JUN 2011

UNIT-3

BEVEL, WORM AND CROSS HELICAL GEARS

WORM GEAR DRIVE

1

A hardened steel worm rotates at 1440 rpm and transmits 12 KW to a phosper bronze gear.

The speed of the worm wheel should be 60 ± 3 % rpm. Design the worm gear drive if an

efficiency of atleast 82% is desired. Assume q = 1, medium shock conditions v = 5m/s,

pressure angle = 20°.

NOV/DEC 2018

2

The input to worm gear shaft is 18 KW and 600 rpm. Speed ratio is 20. The worm is to be of

hardened steel and the wheel is made of chilled phosphor bronze. Considering wear and

strength, design worm and worm wheel.

APR/MAY 2018

3

Design a worm gear drive to transmit 22.5 kW at a worm speed of 1440 rpm. Velocity ratio is

24:1.An efficiency of at least 85% is desired. The temperature raise should be restricted to

40˚C. Determine the required cooling area.

NOV/DEC 2017

APR/MAY 2015

NOV/DEC 2011

MAY/JUN 2013

4

Design a worm gear drive to transmit 20 HP from a worm at 1440 rpm to the worm wheel.

Assume the bronze is sand chill cast. The speed of the wheel should be 40 ± 2% rpm; initial

sliding velocity can be assumed as 3 m/s and efficiency as 80%.

APR/MAY 2017

5

A hardened steel worm rotates at 1440 rpm and transmits 20 kW to a phosphor bronze gear.

The speed of the worm gear should be 60 rpm. Design the worm gear drive if an efficiency of

at least 82% is desired.

NOV/DEC 2016

APR/MAY 2016

6

The input to worm gear shaft is 18 kW at 600 rpm. Speed ratio is 20. The worm is to be

hardened steel and the wheel is made of chilled phosphor bronze. Considering wear strength,

design worm and worm wheel.

NOV/DEC 2015

NOV/DEC 2013

MAY/JUN 2011

7

A hardened steel work rotates at 1440 rpm and transmits 12 kW to a phosphor bronze gear.

The speed of the worm wheel should be 60 ± 3% rpm. Design a worm gear drive if an

efficiency of at least 82% is desired.

NOV/DEC 2014

8

A 2 kW power is applied to a worm shaft at 720 mm. The worm is of quadruple start with 50

mm as pitch circle diameter. The worm gear has 40 teeth with 5 mm module. The pressure

angle in the diametral plane is 20˚. Determine (i) the lead angle of the worm, (ii) velocity

ratio, and (iii) centre distance. Also calculate efficiency of the worm gear drive, and power

lost in friction.

APR/MAY 2014

9 Design a worm drive for a speed reducer to transmit 15 kW at 1440 rpm of the worm shaft.

The desired wheel speed is 60 rpm. Select suitable worm and wheel materials.

NOV/DEC 2012

APR/MAY 2011

10

Design a worm gear drive and determine the power loss by heat generation. The hardened

steel worm rotates at 1500 rpm and transmits 10 kW to a phosphor bronze gear with gear ratio

of 16.

MAY/JUN 2012

11 Design a worm drive for a speed reducer to transmit 15 kW at 1440 rpm of the worm shaft.

The desired wheel speed is 60 rpm. Select suitable worm and wheel materials. APR/MAY 2011

BEVEL GEAR DRIVE

1

Design a pair of bevel gears to transmit 10 KW at a pinion speed of 1440 rpm. Required

transmission ratio is 4. Material of gears is 15Ni 2Cr 1 Mo 15 steel (BHN = 400). The tooth

profiles of the gears are of 20° composite form. Assume minimum number of teeth as 20, v =

5m/s and medium shock conditions.

NOV/DEC 2018

2

Design a bevel gear drive to transmit 7 KW at 1600 rpm for the following data.

Gear ratio = 3

Material for pinion and gear = C45 Steel

Life = 10,000 hours

APR/MAY 2018

3 Design a bevel gear drive to transmit 7.36 kW at 1440 rpm for the following data, gear ratio

is 3. Material for pinion and gear C 45 surface hardened.

NOV/DEC 2017

APR/MAY 2011

4

Design a bevel gear drive to transmit 7.5 kW at 1440 rpm. Gear ratio 3. Pinion and gear are

made of forged C 45 steel. Life of gears 10000 Hrs. Assume surface hardened heat treatment

and IS quality 6

APR/MAY 2017

5

Design a bevel gear drive to transmit 3.5 kW with driving shaft speed is 200 rpm. Speed ratio

required is 4. The drive is non-reversible. Pinion is made of steel and wheel is made of CI.

Assume a life of 25000 Hrs.

NOV/DEC 2016

APR/MAY 2016

NOV/DEC 2011

6

Design a straight bevel gear drive between two shafts at right angles to each other. Speed of

the pinion shaft is 360 rpm and the speed of the gear wheel shaft is 120 rpm. Pinion is of steel

and wheel of cast iron. Each gear is expected to work 2 hour/day for 10 years. The drive

transmits 9.37 kW.

NOV/DEC 2015

NOV/DEC 2013

7 Design a pair of straight bevel gears for two shafts whose axis are at right angles. The power

transmitted is 25 kW. The speed of pinion is 300 rpm and the gear is 120 rpm. APR/MAY 2015

8 Derive expressions for determining the forces acting on a bevel gear with suitable

illustrations. NOV/DEC 2014

9 Design a bevel gear drive to transmit 10 kW power at 1440 rpm. Gear ratio is 3 and life of

gears 10000 Hrs. Pinion and gear are made of C 45 steel and minimum no of teeth as 20 APR/MAY 2014

10 Design a bevel gear drive to transmit 7 kW at 1600 rpm for the following data. Gear ratio is

3, Material for pinion and gear is C 45 steel, life of gear is 10000 Hrs. MAY/JUN 2013

11

A pair of bevel gears is to be used to transmit 8 kW from a pinion rotating at 240 rpm to a

gear mounted on a shaft which intersects the pinion shaft at an angle of 70°. Assuming that

the pinion is to have an outside pitch diameter of 180 mm, a pressure angle of 20°, a face

width of 30 mm, and gear shaft is to rotate at 80 rpm, determine the forces on the gears and

the torque produced about the axis

NOV/DEC 2012

12 Design a bevel gear drive to transmit 7.5 kW power at 1500 rpm. Gear ratio is 3.5 materials

for pinion and gear are made of C 45 steel. Minimum no of teeth is to be 25 MAY/JUN 2012

UNIT-4

GEAR BOXES

6 SPEED GEAR BOX

1

Sketch the arrangement of a six speed gear box for a minimum speed of 460 rpm and a

maximum speed of 1400 rpm. Draw the speed diagram and kinematic arrangement

showing number of teeth in all gears. Check whether all the speeds obtained through the

selected gears are within ±2% of standard speeds. The drive is from electric motor giving

2.25 kW at 1440 rpm.

NOV/DEC 2016

2 A six speed gear box is required to provide output speeds in the range of 125 to 400 rpm,

with a step ratio of 1.25 and transmit a power of 5 kW at 710 rpm. Draw the speed MAY/JUN 2016

TWO MARKS

1 List the forces acting on bevel gears. NOV/DEC 2018

2 What is irreversibility in worm gear. NOV/DEC 2018

3 When do we use bevel gears. APR/MAY 2018

4 In which gear drive, self locking is available. APR/MAY 2018

5 What are the disadvantages of worm gear drive? NOV/DEC 2017

6 What is meant by Mitre gear? NOV/DEC 2017

7 What is known as formative no of teeth on bevel gear? APR/MAY 2017

8 Write the conditions of self – locking of worm gears in terms of lead and pressure angles. APR/MAY 2017

9 What is a crown gear? NOV/DEC 2016

10 Write some applications of worm-gear drive. NOV/DEC 2016

11 How bevel gears are manufactured? MAY/JUN 2016

12 What is helical angle of worm? MAY/JUN 2016

13 What is the difference between an angular gear and miter gear? NOV/DEC 2015

NOV/DEC 2013

14 What kind of contact occurred between worm and wheel? How does this differ from other

gears? NOV/DEC 2015

15 State the advantages of herringbone gear. APR/MAY 2015

16 What is a zerol bevel gear? APR/MAY 2015

17 What is virtual number of teeth in bevel gears? NOV/DEC 2014

APR/MAY 2014

18 Mention the advantages of worm gear drive. NOV/DEC 2014

19 Define the term cone distance and face angle APR/MAY 2014

20 Why phosphor bronze is widely used for worm gears? NOV/DEC 2013

21 What are the forces acting on bevel gear? MAY/JUN 2013

22 When do we employ crossed helical gear? MAY/JUN 2013

23 Mention the types of failure in worm gear drives. NOV/DEC 2012

24 Where do we use worm gears? NOV/DEC 2012

25 Give the speed ratio range of worm-wheel drive. MAY/JUN 2012

26 What is the reference angle? How is it related to speed ratio of bevel gear ratio? MAY/JUN 2012

27 What is the effect of increasing the pressure angle in gears? NOV/DEC 2011

28 Why is dynamic loading rarely considered in worm gear drives? NOV/DEC 2011

29 Under what situation, bevel gears are used? APR/MAY 2011

30 In worm gear drive, only the wheel is designed. Why? APR/MAY 2011

31 What are the applications of skew helical gears? MAY/JUN 2011

32 List the different types of gear mechanism. MAY/JUN 2011

diagram and kinematic diagram. Determine the number of teeth module and face width of

all gears, assuming materials for gears. Determine the length of gear box along the axis of

the gear shaft.

3

A sliding mesh gear box is to be used for 4 forward and 1 reverse speeds. First gear speed

ratio is 5.5 and reverse gear speed ratio is 5.8. Clutch gear on clutch shaft and gear 9in

constant mesh) on lay shaft has speed ratio of 2. Calculate the number of teeth on all

gears. Assume that the minimum number of teeth on any gear should not be less than 18.

Calculate actual gear ratios. Assume that the geometric progression for gear ratios, top

gear(fourth), third gear, second and first gear is 1:x:x2:x3

NOV/DEC 2014

4

Sketch the arrangements of a six speed gear box. The minimum and maximum speeds

required are around 460 and 1400 rpm. Drive speeds as 1440 rpm. Construct speed

diagram of the gear box and obtain various reduction ratios. Use standard output speeds

and standard step ratio. Calculate number of teeth in each gear and verify whether the

actual output speeds are within +2% of standard speeds.

MAY/JUN 2014

9 SPEED GEAR BOX

1

A nine speed gear box used as a headstock gear box of a turret lathe is to provide a

speed range of 180 rpm to 1800 rpm. Using standard step ratio, draw the speed

diagram, and the kinematic lay out. Also find and fix the number of teeth on all gears.

NOV/DEC 2018

2

Draw the kinematic diagram and speed diagram of the headstock gear box of a turret

lathe having arrangement for 9 spindle speeds ranging from 31.5 rpm to 1050 rpm.

Calculate the number of the teeth on each gear. Minimum number of teeth on gear is

25. Also calculate the percentage deviation of obtainable speeds from the calculated

ones.

NOV/DEC 2017

3

Design a 9 speed gear box for a milling machine with speeds ranging from 56 to 900

rpm. The input speed is 720 rpm. Make a neat sketch of the gear box. Indicate the

number of teeth on all the gears and their speeds. Assuming the gears and shafts are

made of C45, calculate module, centre distance and diameter of the spindle.

APR/MAY

2017

4

Draw the kinematic diagram and speed diagram of the headstock gear box of a turret

lathe having arrangement for 9 spindle speeds ranging from 31.5 rpm to 1050 rpm.

Calculate the number of the teeth on each gear. Minimum number of teeth on gear is

25. Also calculate the percentage deviation of obtainable speeds from the calculated

ones.

MAY/JUN 2016

5

A nine speed gear box, used as head stock gear box of a turret lathe is to provide a

speed range of 180 rpm to 1800 rpm using standard step ratio. Draw the speed diagram

and kinematic arrangement showing number of all gears.

NOV/DEC 2015

6

Design a 9 speed gear box for a machine to provide speeds ranging from 100 rpm to

1500 rpm. The input is from a motor of 5 kW at 1440 rpm. Assume alloy steel for the

gears.

APR/MAY

2015

7

A nine speed gear box, used as head stock gear box of a turret lathe is to provide a

speed range of 180 rpm to 1800 rpm using standard step ratio. Draw the speed diagram

and kinematic arrangement showing number of all gears. Also find and fix the number

of teeth on all gears.

NOV/DEC 2013

8 Design a 9 speed gear box to give output speeds between 280 and 1800 rpm. The input

power is 5.5 kW at 1440 rpm. Draw the kinematic layout and speed diagram. MAY/JUN 2013

Determine the number of teeth on all gears.

12 SPEED GEAR BOX

1

Design the layout of a 12 speed gear box for a lathe. The minimum and maximum

speeds are 100 and 1200 rpm. Power is 5 KW from 1440 rpm induction motor.

Construct the speed diagram using a standard speed ratio. Calculate the number

of teeth in each gear wheel and sketch the arrangement of the gear box.

APR/MAY

2018

2

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

to 355 rpm. Design the gear box. 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. Also sketch the speed diagram.

NOV/DEC

2017

3

Design a 12 speed gear box. The required speed range is 100 to 355 rpm. Draw

the ray diagram, kinematic arrangement and find the number of teeth on each

gear. Check for interference.

APR/MAY

2017

4

Design a layout of a 12 speed gear box for a milling machine having an output of

speeds ranging from 25 to 600 rpm. Power is applied to the gear box from a 22.5

kW induction motor at 1440 rpm. Construct the speed diagram using standard

speed ratio. Calculate the number of teeth on each gear and sketch the

arrangement of the gear box .

NOV/DEC

2016

5 Design a 12 speed gear box for a lathe. The minimum and maximum speeds are

100 and 1200 rpm. Power is 5 kW from 1440 rpm induction motor.

APR/MAY

2015

6

Draw the ray diagram and kinematic layout of a gear box for an all geared

headstock of a lathe. The maximum and minimum speeds are to be 600 and 23

rpm respectively. Number of speeds is 12 and drive is from a 3000 W electric

motor running at 1440 rpm.

MAY/JUN

2014

7

Design a 12 speed gear box for a lathe. The minimum and maximum speeds are

100 and 1200 rpm. Power is 5 kW from 1440 rpm induction motor. Draw the

speed and kinematic diagram. Also calculate the number of teeth on all gears.

MAY/JUN

2013

18 SPEED GEAR BOX

1

Sketch the speed diagram and the kinematic layout for an 18 speed gear box

for the following data. Motor speed = 1440 rpm, minimum output speed = 16

rpm, maximum output speed = 800 rpm, arrangement 2x3x3. List the speeds

of all the shafts when the output speed is 16 rpm.

NOV/DEC 2018

2

Design a gear box to give 18 speeds for a spindle of a milling machine. The

drive is from an electric motor of 4 KW at 1000 rpm. Maximum and

minimum speeds of the spindle are to be around 650 rpm and 35 rpm

respectively.

APR/MAY 2018

3

A gear box is to give 18 speeds for a spindle of milling machine. Maximum

and minimum speeds of the spindle are to be around 650 and 35 rpm

respectively. Find the speed ratios which will give the desired speeds and

draw the structural diagram and kinematic arrangement of the drive

NOV/DEC 2015

4 A sixteen speed gear box is required to furnish output speeds in the range of

100 to 560 rpm. Sketch the kinematic arrangement and draw the speed

NOV/DEC 2014

diagram.

5

An 18 speed gear box is required to give output speeds are ranging from 35

rpm to 650 rpm. The input power is 3.75 kW at 1440 rpm. Draw the structural

diagram and kinematic arrangement of gears.

NOV/DEC 2013

TWO MARKS

1 Define progression ratio. NOV/DEC 2018

2 List out the all possible arrangements to achieve 16 speed gear box. NOV/DEC 2018

3 For what purpose we are using gear box. APR/MAY 2018

4 What is a speed diagram. APR/MAY 2018

5 Draw the ray diagram for a 12 speed gear box. NOV/DEC 2017

6 Write any two principles to be followed to obtain optimum design in gear box. NOV/DEC 2017

7 Why geometric progression is selected for arranging the speeds in gear boxes? APR/MAY 2017

8 What does the ray diagram of gear box indicate? APR/MAY 2017

9 Differentiate ray diagram and structural diagram. NOV/DEC 2016

10 List any two methods used for changing speeds in gear boxes. NOV/DEC 2016

11 What is multi speed gear box? MAY/JUN 2016

12 What is R20 series?? MAY/JUN 2016

13 Define progression ratio. NOV/DEC 2015

14 Write the significance of structural formula. NOV/DEC 2015

15 Draw the ray diagram for a 6 speed gear box APR/MAY 2015

16 In which gear drive, self locking is available? APR/MAY 2015

17 What are preferred numbers? NOV/DEC 2014

18 Specify four types of gear boxes. NOV/DEC 2014

19 What is step ratio? Name the series in which speeds of multispeed gear box are

arranged. APR/MAY 2014

20 Sketch the kinematic layout of gears for 3 speeds between shafts. APR/MAY 2014

21 What is step ratio? NOV/DEC 2013

22 State any three basic rules to be followed while designing a gear box. NOV/DEC 2013

23 What are preferred numbers? MAY/JUN 2013

24 What are the possible arrangements to achieve 12 speeds from a gear box? MAY/JUN 2013

25 List four applications where constant mesh gear box is used. NOV/DEC 2012

26 What are the conditions required for interchangeability in toothed gears? NOV/DEC 2012

27 What is step ratio in gear box? APR/MAY 2012

28 What is meant by ray diagram? APR/MAY 2012

29 Distinguish between structural diagram and speed diagram. NOV/DEC 2011

30 What are the methods of lubrication in speed reducers? NOV/DEC 2011

31 What are preferred numbers? APR/MAY 2011

32 What are the possible arrangements to achieve 12 speeds from a gear box? APR/MAY 2011

33 What is the function of spacers in gear box? MAY/JUN 2011

34 List out the basic rules to be followed for optimum gear box design. MAY/JUN 2011

UNIT-5

CAMS, CLUTCHES AND BRAKES

DESIGN OF CLUTCH

1

A single plate clutch transmits 25 KW at 900 rpm. The maximum pressure

intensity between the plates is 85 KN/m2. The ratio of radii is 1.25. both sides of

the plates are effectives and the co efficient of friction is 0.25. determine (i) the

inner diameter of the plate and (ii) the axial force to engage the clutch. Assume

theory of uniform wear.

NOV / DEC 2018

NOV / DEC 2013

2

A single disk clutch having one pair of contacting surface is required to transmit

10 KW at 720 rpm under normal operating condition. Due to space limitation the

outer diameter should be limited to 250 mm. the coefficient of friction is 0.25

and the permissible intensity of pressure is 0.5 N/mm2. Use (a) uniform pressure

theory and (b) uniform wear theory and determine the clutch dimensions.

APR / MAY 2018

3

An automobile engine has an output of 80KW at 3000 rpm. The mean diameter

of the clutch is 200mm with a permissible pressure of 0.2 N/mm2. friction lining

is of asbestos with M=0.22. What should be the inner diameter of the disc? Take

both the sides of the plates with friction lining as effective. There are 8 spring

and axial deflection in spring is limited to 10mm. give G=80KN/mm2 spring

index may be taken as b.

NOV/DEC 20014

4

A power of 20 KW is to be transmitted through a cone clutch at 500 rpm. For

uniform wear condition, find the main dimensions of clutch and shaft. Also

determine the axial force required to engage the clutch. Assume co-efficient of

friction as 0.25, the maximum normal pressure on the friction surface is not to

exceed 0.08 Mpa, and take the design stress for the shaft materials as 40 Mpa.

MAY/JUNE 2006

MAY/JUNE 2015

5

Explain with a neat sketch the working of a single plate clutch. Derive an

expression for the torque to be transmitted by clutch assuming uniform pressure

condition and uniform wear condition.

AU QP

6

A multi plate clutch with both sides effective transmits 30KW at 360 rpm. Inner

and outer radii of the clutch discs are 100mm and 200mm respectively. The

effective co-efficient of friction is 0.25. an axial load of 600N is applied.

Assuming uniform wear conditions, find the number of discs required and the

maximum intensity of pressure developed.

MAY/JUN 2016

7

A multi plate clutch, steel on bronze is to transmit 6KW power at 750 rpm. The

inner radius of contact surface is 4 cm and outer radius is 7 cm. the clutch plates

operate in oil, so the co-efficient of friction is 0.1. the average pressure is 0.35

N/mm2. Determine (i) the total number of steel and bronze friction discs. (ii)

actual axial force required. (iii) actual average pressure (iv) actual maximum

pressure.

NOV/DEC 2016

8

A plate clutch with maximum diameter 6cm has maximum lining pressure of

350Kpa. The power to be transmitted at 400 rpm is 135 KW and µ = 0.3. find

inside diameter and spring force required to engage the clutch. Springs with

spring index 6 and material of the spring is steel with safe shear stress 600 Mpa

are used. Find the diameter if 6 springs are used.

MAY/JUN 2014

9

Explain with a neat sketch the working of a single plate clutch. derive an

expression for the torque to be transmitted by clutch assuming

(i) uniform pressure condition, and

NOV/DEC 2015

(ii) Uniform wear condition.

DESIGN OF CAMS AND BRAKES

1

Determine the capacity and the main dimensions of a double block brake for the

following data. The brake sheave is mounted on the cast iron drum shaft. The hoist with

its load weights 45 KN and moves downwards with a velocity of 1.15 m/s. the pitch

diameter of the hoist drum is 1.25 m. the hoist must be stopped within a distance of 3.25

m. the kinetic energy of the drum may be neglected. Assume sintered metal block shoe,

equal friction force on each shoe, continuous service and poor heat condition.

NOV / DEC

2018

2

A single block brake as shown in fig. has the drum diameter 250 mm. the angle of

contact is 90° and the coefficient of friction between the drum and the lining is 0.35. if

the torque transmitted by the brake is 80,000 N-mm, find the force required to operate

the brake.

ARP / MAY

2018

3

Derive an expression to determine the braking torque for an internal expanding shoe

brake.

AU QP

4

Design a differential band brake for a winch lifting a load of 20 KN through a steel wire

rope wound around a barrel of 600mm diameter. The brake drum keyed to the barrel

shaft, is 800mm diameter and the angle of lap of the band over the drum is about 240°

operating arms of the brake are 50mm and 250mm. the length of operating level is

1.6m.

MAY/JUNE

2006

MAY/JUNE

2015

5

A 50 Kg wheel, 0.5m in diameter turning at 150 rpm is stationary bearing is brought to

rest by pressing a brake shoe radially against the rim with a force of 100N. if the radius

of gyration of wheel 0.2m. how many revolutions will the wheel make before coming to

rest? Assume that the co-efficient of friction between shoe and rim has the steady valve

of 0.25.

MAY/JUN

2016

6

Design a cam for operating the exhaust valve of an oil engine. It is required to give

equal uniform acceleration and retardation during opening and closing or the valve,

each of which corresponding to 60° of cam rotation. The valve should remain in the

fully open position for 20° of cam rotation. The lift of valve is 37.5mm and the least

radius of the cam is 50mm, the follower is provided with a roller of 50mm diameter and

its line of stroke passes through the axis of the cam.

APR/MAY

2007

APR/MAY

2012

NOV/DEC

2015

7

A single shoe brake is shown in figure. The diameter of drum is 250mm and angle of

contact is 90°. If the operating force of 750N is applied at the end the of the lever and

M=0.35, Determine the torque that may be transmitted by the brake.

NOV/DEC

2016

8 Describe with the help of a neat sketch the principles of an internal expanding shoe, also

deduce the expression for the braking torque.

NOV / DEC

2013

9

A hydraulically operated clutch is to be designed for an automatic lathe. Determine the

number of plates and operating force required for the clutch to transmit 35 N-m. the

clutch is to be designed to slip under 300% of rated torsional moment to protect the

gears and other part of the drive, the limits for the diameter of friction surface due to

space limitation are 100mm and 62.5mm, this clutch is to operate in an oily atmosphere.

MAY/JUN

2014

10 Derive an expression to determine the braking torque for an internal expanding shoe

brake.

NOV/DEC

2014

TWO MARKS

1 Name few commonly used friction materials. NOV/DEC 2018

2 What do you meant by self locking brake. NOV/DEC 2018

3 What are the types of brakes used in modern vehicles. APR/MAY 2018

4 How does the function of a brake differ from that of a clutch. APR/MAY 2018

5 What is the difference between dry and wet clutch. NOV/DEC 2017

6 What is meant by self-energizing brakes? NOV/DEC 2017

7 Differentiate a brake and a dynamo meter. APR/MAY 2017

8 Double-shoe brakes are preferred than single-shoe brake. Why? APR/MAY 2017

9 Mention few applications of cams. NOV/DEC 2016

10 What is meant by self-energizing brakes? NOV/DEC 2016

11 What is the function of clutch in a transmission system? MAY/JUN 2016

12 What is the significance of pressure angle in cam design? MAY/JUN 2016

13 Name the profile of cam that gives no jerk. NOV/DEC 2015

14 What is meant by positive clutch? NOV/DEC 2015

15 If a multidisc clutch has 6 discs in driving shaft and 7 discs in driven shaft, then how

many no of contact surfaces it will have? APR/MAY 2015

16 Why in automobiles, braking action when traveling in reverse is not as effective as

when moving forward? APR/MAY 2015

17 Differentiate between uniform pressure and uniform wear theories adopted in the

design of clutches. NOV/DEC 2014

18 In a hoisting machinery, what are the different energies absorbed by a brake system? NOV/DEC 2014

19 Classify clutches based on the coupling methods. MAY/JUN 2014

20 What is meant by self-energizing brake? MAY/JUN 2014

21 Define pitch point in cam. NOV/DEC 2013

22 Differentiate between clutch and a brake. NOV/DEC 2013

23 What is the axial force required at the engagement and disengagement of cone clutch? MAY/JUN 2013

24 What is self-locking brake? MAY/JUN 2013

25 What is self-locking brake? NOV/DEC 2012

26 Distinguish between a coupling and clutch. NOV/DEC 2012

27 State the profile of cam that gives no jerk and mention how jerk is eliminated. APR/MAY 2012

28 Why is it necessary to dissipate the heat generated during clutch operation? APR/MAY 2012

29 What are the factors upon which the torque capacity of a clutch depends? NOV/DEC 2011

30 What is self-locking brake? NOV/DEC 2011

31 What is self-locking brake? APR/MAY 2011

32 Name few commonly used friction materials. APR/MAY 2011

33 Under what condition of a clutch, uniform rate of wear assumption is more valid. MAY/JUN 2011

34 What should be the temperature rise be kept within the permissible range in brakes? MAY/JUN 2011