design of transmission system unit i design of flexible

SEM-6 6th

Semester – B.E., / B. Tech.

M601 Department Of Mechanical Engineering

ME8651 DESIGN OF TRANSMISSION SYSTEM

Unit – I DESIGN OF FLEXIBLE ELEMENTS

Part-A (10 X 2 = 20 Marks)

No Question Level Competence Mark

1.1 Name the types of transmission belt L1 Remembering 2

1.2 List the commonly used belt L1 Remembering 2

1.3 Define law of belting L1 Remembering 2

1.4 Explain the term "Crowning of Pulleys" L1 Remembering 2

1.5 Develop the formula for maximum tension in a belt L5 Creating 2

1.6 Define slip in a flat belt drive L1 Remembering 2

1.7 Describe creep in a flat belt L2 Understanding 2

1.8 Illustrate the factors affecting coefficient of friction L3 Applying 2

1.9 Illustrate the factors to be considered in design of

belt drives

L3 Applying 2

1.10 List the factors affecting the belt life. L2 Understanding 2

2.1 Describe the meaning of wire designation 6x12? L2 Understanding 2

2.2 Describe the stresses induced in wire ropes? L5 Evaluating 2

Nadar Saraswathi College of Engineering and Technology,

Vadapudupatti, Theni - 625 531

(Approved by AICTE, New Delhi and Affiliated to Anna University, Chennai)

Format No. NAC/TLP-

07a.12

Rev. No. 02

Date 12-11-2015

Total Pages 01

Question Bank for the Units – I to V

2.3 Explain silent chain. L4 Analysing 2

2.4 Classify the types of failure in chain drive. L4 Analysing 2

2.5 Explain the main classification of chains? L5 Evaluating 2

2.6 Explain the chordal actions in chain drive. L2 Understanding 2

2.7 Integrate why odd number of teeth for sprocket is

preferred.

L2 Understanding 2

2.8 Discuss the different types of flat belt drives? L1 Remembering 2

2.9 List the advantage of flat belt drives. L1 Remembering 2

2.10 Integrate why the face of the pulley is crowned? L2 Understanding 2

Unit II SPUR GEARS AND PARALLEL AXIS HELICAL GEARS


3.1 Describe the advantage of gear drives. L2 Understanding 2

3.2 Define law of gearing L1 Remembering 2

3.3 Describe the following (i) Pressure angle (ii) Diametrical pitch

L2 Understanding 2

3.4 Define module. L1 Remembering 2

3.5 Describe backlash. L2 Understanding 2

3.6 Explain undercutting in gears. L5 Evaluating 2

3.7 Explain the interference in gears? L4 Analysing 2

3.8 Classify the main types of gear tooth failure? L3 Applying 2

3.9 Explain the requirement of gear material. L5 Evaluating 2

3.10 List the disadvantages of Helical Gears. L1 Creating 2

4.1 Integrate the materials commonly used for gears. L4 Analysing 2

4.2 Differentiate involute and cycloid profiles L1 Creating 2

4..3 Integrate the common profiles used for gear tooth. L3 Applying 2

4.4 Illustrate interchange ability of gears. L3 Applying 2

4.5 Illustrate herringbone gear and its application. L4 Analysing 2

4.6 Differentiate Spur and helical gear L2 Understanding 2

4.7 Describe virtual number of teeth in helical gear? L1 Remembering 2

4.8 List the advantages of Spur Gears. L1 Remembering 2

4.9 List the disadvantage of Spur Gears. L1 Remembering 2

4.10 List the advantages of Helical Gears. L1 Remembering 2

Unit III BEVEL, WORM AND CROSS HELICAL GEARS


5.1 Give the use of bevel gears L2 Understanding 2

5.2 Generalize what are the various force acting on

bevel gears?

L1 Creating 2

5.3 Explain Mitre gears. L4 Analysing 2

5.4 Explain crown gears. L4 Analyzing 2

5.5 Classify the bevel gears. L3 Applying 2

5.6 Define Zerol bevel gear. L1 Remembering 2

5.7 Show when do you prefer worm and worm wheel

drive?

L3 Applying 2

5.8 List the advantages of worm gear drive. L1 Remembering 2

5.9 List the disadvantages of worm gear drive. L1 Remembering 2

5.10 Explain " crossed helical gear drive is not used for

power

L1 Remembering 2

6.1 Define the terms of worm gear drive. 1. Helix angle

2. Lead angle

L2 Understanding 2

6.2 Describe in which gear drive self-locking is

available?

L1 Creating 2

6.3 Generalize what is irreversibility in worm gears and how is it

L2 Understanding 2

6.4 Describe about helix angle of a herringbone gear? L1 Remembering 2

6.5 List the various materials used for the production of

gears?

L2 Understanding 2

6.6 Describe the various losses in the worm gear. L3 Applying 2

6.7 Illustrate Hypnoid gear with example. L4 Analysing 2

6.8 Differentiate between the spiral bevel gears and

hypnoid gears.

L1 Remembering 2

6.9 List the materials used for the manufacture of worm

and worm

L5 Evaluating 2

6.10 Explain why worm is made of harder material than

worm wheel

L1 Remembering 2

Unit IV GEAR BOXES


7.1 Formulate the ray diagram for a six speed gear box. L1 Creating 2

7.2 Define step ratio L1 Remembering 2

7.3 Where do we use speed reducers? L1 Remembering 2

7.4. Demonstrate the general structural diagram of gear

box.

L3 Applying 2

7.5 Describe about preferred numbers in gearbox

design.

L2 Understanding 2

7.6 Distinguish between structural diagram and ray

diagram.

L2 Understanding 2

7.7 List the function of structural diagram. L1 Remembering 2

7.8 Give number of possible arrangements to achieve 12

speeds from

L2 Understanding 2

7.9 Give number of possible arrangements to achieve 9

speeds from a

L2 Understanding 2

7.10 Illustrate ray diagram for a six speed gear box. L4 Analysing 2

8.1 Explain multi speed gear box L1 Remembering 2

8.2 List the use of gear box in machine tool L4 Analysing 2

8.3 Explain the basic rules to be followed for optimum

gear box

L5 Evaluating 2

8.4 Explain the possible arrangements to achieve 18 speeds from a

L5 Evaluating 2

8.5 Summarize the number of preferred numbers used

for design

L4 Analysing 2

8.6 Explain what the ray diagram of gear box indicates. L1 Creating 2

8.7 Formulate the general structural formula for gear

box design.

L1 Remembering 2

8.8 List the application of speed reducer. L1 Remembering 2

8.9 Define gear box. L3 Applying 2

8.10 Classify the types of speed reducer unit. L2 Understanding 2

Unit V CAMS, CLUTCHES AND BRAKES


9.1 Define CAM. L1 Remembering 2

9.2 List the types of CAMs. L1 Remembering 2

9.3 Define trace point in CAM. L1 Remembering 2

9.4 Describe stroke in CAM. L2 Understanding 2

9.5 Integrate the importance of pressure angle in CAM

design.

L1 Creating 2

9.6 Explain the term undercutting in CAM L4 Analysing 2

9.7 Explain the function of a clutch L4 Analysing 2

9.8 Name four materials used for lining of friction

surfaces in

L1 Remembering 2

9.9 Integrate the desirable properties of lining materials

frictional

L1 Creating 2

9.10 Describe the important properties of friction

material to be used

L2 Understanding 2

10.1 Explain self-locking brakes L5 Evaluating 2

10.2 Explain self – energizing brake L5 Evaluating 2

10.3 Classify the different types of brakes L3 Applying 2

10.4 List few properties of brake friction materials. L1 Remembering 2

10.5 Differentiate clutch and brake. L2 Understanding 2

10.6 Classify the different types of followers L3 Applying 2

10.7 Describe jerk or pulse in CAM. L2 Understanding 2

10.8 Explain the term" fading of brakes" L4 Analysing 2

10.9 Classify the types of clutch. L3 Applying 2

10.10 List the advantages and applications of multi-plate

clutch.

L1 Remembering 2


Part B(13 X 5 = 65 Marks)

11.a-1 Design a FLAT belt drive to transmit 10 KW at 1500

rpm to a line shaft to run at 500 rpm. The diameter of

larger pulley is 750 mm. The distance between the pulley centres is 2 m.

L1

Creating 13

11.a-2 Design a fabric flat belt drive to transmit 12KW at

750 rpm to a line shaft to run at 250 rpm. The

diameter of larger pulley is 900 mm. The distance

between the pulley centre is 1 m.

L1

Creating 13

11.a-3 A 30 KW 1440rpm motor is to drive a compressor

by means of V-belts.the diameter of pulleys are

220mm and 750mm.the centre distance between the

compressor and motor is 1440mm.design a suitable

drive.

L1

Creating 13

11.a-4 Design a V-Belt drive to the following

specifications. i.) Power to be transmitted = 75KW

ii.) Speed of the driving wheel (N1)=1440rpm

iii.) Speed of the driven wheel(N2)= 400rpm

iv.) Centre distance = 2500mm v.)Diameter of the

driving wheel(d) = 300mm.v.) Service = 16hours/day

L1

Creating

13

11.a-5 A 600rpm blower is to be driven by a 10KW,

1440rpm motor approximately 750mm away. Design

a suitable chain drive. L1

Creating 13

11.a-6 Design a suitable chain drive,to operate a compressor

from a 15 KW electric motor at 900rpm.the

compressor is to run at a speed of 200rpm.the

minimum centre distance should be 550mm

respectively

L1

Creating 13

11.a-7 Select a wire rope for a vertical mine hoist to lift a

load of 55KN from a depth of 350 meters and a rope

speed of 600 m/min is to be attained in 20 seconds.

L1

Creating 13

11.a-8 Design a rope drive for a passenger lift, for a lifting

load of 75KN from a depth of 400 m in a rope speed

of 500m/min which must be done in a average of

30seconds.

L1

Creating 13


Part-B (13 X 5 = 65 Marks)

12.a-1 Design and draw a straight spur gear drive to transmit

35KW. The pinion speed is 720rpm and the speed

ratio is 2.Both the gears are made up of the same

surface hardened carbon steel with 55RC and core

hardness less than 350BHN. Ultimate strength is

720N/mm2 and yield strength is 360N/mm2.

L1

Creating 13

12.a-2 Design a spur gear drive to transmit 22KW at L1 Creating 13

1000rpm, speed reduction is 2.5. The centre distance between the gear shafts is approximately 350mm. The materials used are pinion-C45, gear wheel-C.I Grade 30.Design the drive

12.a-3 Design and draw a straight spur gear drive to transmit

30KW. The pinion speed is 700rpm and the speed

ratio is 2.Both the gears are made up of the same

surface hardened carbon steel with 55RC and core

hardness less than 450BHN. Ultimate strength is

730N/mm2 and yield strength is 340N/mm2.

L1

Creating 13

12.a-4 Design a pair of helical gears to transmit a power of

35KW at a speed reduction ratio of 4:1. The input of

a motor shaft produces a rotation of 4000rpm.

L1

Creating 13

12.b-5 Design a helical gear drive to transmit a power of 15KW at 1400rpm to the following specifications. Speed reduction is 3, pressure angle is 20̊ , Helix angle is 15̊, The material of both the gears is C45 steel, Allowable static stress is 180N/mm2 and young’s modulus of the material =2 X 105 N/mm2

L1

Creating 13

12.b-6 Design a pair of helical gears to transmit 25KW at a

speed reduction ratio of 5:1. The input shaft runs at

2000rpm.

L1

Creating 13



13.a-1 Design a bevel gear to transmit a power of 15KW at

600 rpm of the pinion. Gear ratio is 2.5, material used

is C20. Ultimate tensile strength is 700N/mm2, Yield

strength is 450 N/mm2.

L6

Creating 13

13.a-2 Design a pair of bevel gears to transmit 15KW at the pinion speed of 1600 rpm, and the gear ratio is 4.Material for gears 15 Ni 2 cr Mo 15/steel. The tooth profiles of the gears are of 20̊ composite form.

L6

Creating 13

13.a-3 Design a BEVEL gear drive to transmit 4 KW.

Speed ratio = 4. Driving shaft speed 225 rpm. The

drive is non-reversible. Assume a life of 25000

hours.

L6

Creating 13

13.a-4 Design a Worm gear drive to transmit 12KW at 1200

rpm. Speed reduction desired is 30:1. The worm is

made of hardened and the wheel of phosphor bronze.

Check the heating capacity of gears and determine the

efficiency.

L6

Creating 13

13.a-5 Design a worm gear drive to transmit a power of

30KW. The worm speed is 1660 rpm, and the

speed of the wheel is 90 rpm. The drive should

have a minimum efficiency of 60% and above.

Depends upon the dimensions of the drive select

suitable materials of worm and worm wheel.

L6

Creating 13

13.a-6 A hardened steel WORM rotates at 1440 rpm and

transmits 12 KW to a phosphor bronze gear with

gear ratio of 16. Design the worm gear drive and

determine the power loss by heat generation.

L6

Creating 13

Unit IV GEAR BOXES


14.a-1 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 diagram and kinematics

diagram. Determine the number of teeth module and

face width of all gears, assuming suitable materials

for the gears.

L6 Creating

13

14.a-2 Design a 9 speed gear box for the following data.

Minimum speed: 100rpm, step ratio: 1.25. The input

is from a 4KW, 1440rpm motor. Draw the speed

diagram, kinematic diagram and indicate the number

of teeth on each gear

L6 Creating

13

14.a-3 Design a nine – speed gear box for a machine to

provide speeds ranging from 100 to 1500 rpm. The

input is from a motor of 5 kW at 1440 rpm. Assume

any alloy steel for the gear.

L6 Creating

13

14.a-4 Select speeds for a 12 speed gear box for a minimum

speed of 16 rpm and a maximum speed of 900rpm.

Draw the speed diagram, kinematic diagram and

indicate the number of teeth on each gear.

L6 Creating

13

14.b-1 Design the layout of a 12 speed gear box for a

milling machine having an output of speeds ranging

from 180 to 2000 rpm. Power is applied to the gear

box from a 6 kW induction motor at 1440 rpm.

Choose standard step ratio and construct the speed

diagram. Decide upon the various reduction ratios

and number of teeth on each gear wheel sketch the

arrangement of the gear box.

L6 Creating 13

14.b-2 A gear box is to be designed for the following

specifications:

Power to be transmitted = 5.5KW

Number of speeds = 9

L6 Creating 13

Minimum speed = 280 rpm

Maximum speed = 1800 rpm

Input motor speed = 1440 rpm

Draw the kinematic layout diagram and the speed

diagram. Determine the number of teeth on all gears.

14.b-3 Design a 16 speed gear box for the following data.

Minimum speed: 100rpm, step ratio: 1.25. The input

is from a 5KW, 1000rpm motor. Draw the speed

diagram, kinematic diagram and indicate the number

of teeth on each gear

L6 Creating

13


Part – B ( 5 X 13 = 65 Marks)

15.a-1 A car engine has its rated output of 12KW. The maximum torque developed is 100 N- m. the clutch used is single plate clutch having two active surfaces. The axial pressure is not to exceed 85KN/m².The external diameter of the friction plate is 1.25 times the internal diameter. Determine the dimensions of the friction plate and the axial force exerted by the springs. Coefficient of friction = 0.3

L3

Applying 13

15.a-2 A multiple disc clutch transmits 55KW of power at 1800 rpm. Coefficient of friction surface is 0.1. Axial intensity of pressure is not to exceed 160KN/m².The internal radius is 80mm and 0.7 times the external radius. find the number of plates needed to transmit the required torque

L3

Applying

13

15.a-3 A cone clutch with semi-cone angle of 15º transmits 10KW at 600 rpm. The normal pressure between the surfaces in contact is not to exceed 1000KN/m². The width of the friction surface is half of the mean diameter. Assume µ = 0.25. Determine (i) inner and outer diameters of the plate (ii) The axial force to engage the clutch.

L3

Applying

13

15.a-4 A centrifugal clutch has four shoes each having a

mass of 5Kg and having its center of gravity at a

radius of 60mm. The diameter of the friction surface

is150mm. the clutch is to transmit 6KW power at a

speed of 1000rpm. Determine the force which must

be exerted by each spring. If the speed of rotation is

gradually increased from rest, at what speed will the

clutch begins to transmit torque? take µ = 0.25.

L3

Applying 13

15.b-1 A single block brake has the diameter of 300mm and

the angle of contact is 120̊. The coefficient of friction is

0.3. If the torque transmitted by the brake is 80N-m,

find the force P required. Assume the length of the

lever (l) = 300mm and distance between centre of

L3

Applying

wheel to fulcrum(x) = 150mm.

15.b-2 A single block brake, the diameter of drum is

250mm and the angle of contact is 90o, the operating

force of 700N is applied at the end of lever which is

at 250mm from the center of the brake block.

Determine the torque that may be transmitted.

Fulcrum is at 200mm from the center of brake block

with an offset of 50mm from the surface of contact.

The coefficient of friction is 0.35.

L3

Applying 13

15.b-3 The layout of a double block brake is shown in

figure -2. The brake is rated at 250N-m at 650rpm.

The drum diameter is 250mm.assuming the co-

efficient of friction as 0.3 and for conditions of

service a pv value of 1000(Kpa) m/s may be

assumed. Determine (i) The spring force “S”

required to set the brake (ii) Width of shoes (iii)

Which shoe will have greater rate of wear?

L3

Applying

13


Part C(15 X 1 = 15 Marks)

16.a-1 Compare all the following with 15 points. (i)bBelt

drive(ii)Chain drive (iii)Rope drive L5 Evaluating 15

16.a-2 (i)Briefly explain the design procedure for a V-Belt d

drive?

(ii)Explain the various stresses induced in flexible

machine elements?

L5 Evaluating 8 + 7

16.b-1 Explain the construction of Silent chain? list its

advantages and disadvantages and give a brief account on

any two applications of Silent chain? L5 Evaluating 15

16.b-2 Write an engineering brief about (i)Ribbed V-Belts

(ii)Timing belts L1 Knowledge 15



17.a-1 Deduce the lewis equation for spur gears and list the

assumptions to be made during the designing stage. L4 Analyzing 15

17.a-2 Briefly explain the design procedure for a spur gear

drive? L2 Understanding 15

17.b-1 (i)what is the major disadvantage of single helical gear?

How can you overcome the above mentioned difficulty

(ii) why is the crossed helical gear drive not used for

power transmission?

L3 Application 7 + 8

17.b-2 Briefly explain the design procedure for a spur gear

drive? L2 Understanding 15


Part C(15 X 1 = 15 Mark]s)

18.a-1 Briefly compare all the types of bevel gears? L5 Evaluating 15

18.a-2 Write down the step by step procedure for the design of

Bevel gears? L2 Understanding 15

18.b-1 Write an engineering brief about any four applications of

worm gear? L3 Application 15

18.b-2 A pair of worm gears is designated as 1/30/10/8.Calculate

(i) center distance. (ii) The speed reduction. (iii)

Dimension of worm. (iv) Dimension of the worm wheel. L4 Analyzing 15

Unit IV GEAR BOXES


19.a-1 Write down the basic rules for optimum Gear box

design and also state that the speeds of a gear box are

in geometric progression.

L1 Understanding 15

19.a-2 A machine tool gearbox is to provide 14 spindle speeds

ranging from 20 to 400 rpm, design a gear box.Consider

any 4 possible different alternates and indicate the best

with reasons.

L4 Analyzing 15

19.b-1 Briefly explain the steps and formulas included in

designing the gear box with an example? L1 Understanding 15

19.b-2 State the advantages and disadvantages of gearbox.eplain

any three application of gear box in detail? L3 Application 15



20.a-1 How can you transmit Torque using Single plate and

Multi-plate clutch? L3 Application 12+3

20.a-2 Briefly explain the Geneva Mechanism with neat sketch

using PSG Data book. L4 Analyzing 15

20.b-1 Derive the expression to determine the braking torque for

an internal expanding shoe brake. L4 Analyzing 15

20.b-2 Describe the design procedure involved in designing the

Disc (or)Plate clutch. L4 Analyzing 15

L1: Knowledge, L2: Comprehension, L3: Application, L4: Analysis, L5: Evaluation, L6: Synthesis

QUESTION BANK SUMMARY

S.NO UNIT DETAILS L1 L2 L3 L4 L5 L6 TOTAL

1 Unit-1

PART-A 7 6 2 2 3 - 20

PART-B 8 - - - - - 08

PART-C 1 - - - 3 - 04

2 Unit-2

PART-A 8 4 3 3 2 - 20

PART-B 6 - - - - - 06

PART-C - 2 1 1 - - 04

3 Unit-3

PART-A 9 4 3 3 1 - 20

PART-B - - - - - 6 06

PART-C - 1 1 1 1 - 04

4 Unit-4

PART-A 8 5 2 3 2 - 20

PART-B - - - - - 7 07

PART-C 2 - 1 1 - - 04

5 Unit-5

PART-A 8 4 3 3 2 - 20

PART-B - - 7 - - - 07

PART-C - - 1 3 - - 04

Total No of Questions

PART-A PART-B PART-C TOTAL

100 34 20 154

Prepared By: Staff Name1: Mr. T.Sudarsanan Staff Name2: Mr. R.Santhaseelan

design of transmission system unit i design of flexible

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