Mechanical Elements: - Function, Sketch, Description, Uses and classification of- Shaft, Axle, Key (Parallel key), Coupling (Rigid Flanged Coupling), Bearing-(Ball bearing), Clutch- Single Plate Clutch, Brake - Disc Brake.

1. Basic Mechanical Engineering
By
Nitin G Shekapure
Unit I
Introduction to Mechanical Engineering
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2. 102013 - Basic Mechanical Engineering (2012 Pattern)
Course Objectives:
1. This course will help the student to acquire knowledge of Mechanical Engineering.
2. Describe the scope of mechanical engineering with multidisciplinary industries.
3. Understand and identify common machine elements with their functions and power
transmission devices.
4. Learn conventional machine tools and understand the concept of design in
mechanical engineering.
5. Impart knowledge of basic concepts of thermodynamics applied to Industrial
applications.
6. Understand laying principles of energy conversion systems and power plants.
By: Nitin Shekapure
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3. 102013 - Basic Mechanical Engineering (2012 Pattern)
Syllabus:
Unit I : Introduction to Mechanical Engineering
Mechanical Elements: - Function, Sketch, Description, Uses and classification of-
Shaft, Axle, Key (Parallel key), Coupling (Rigid Flanged Coupling), Bearing-(Ball
bearing), Clutch- Single Plate Clutch, Brake - Disc Brake.
Power Transmission Devices: Construction, working, comparison, applications and
classification of: Belt Drive (Flat and V Belt), Chain Drive and Spur Gear Drive arranged
with simple gear train.
Reference Book – Design of Machine Elements by V. B. Bhandari
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4. 102013 - Basic Mechanical Engineering (2012 Pattern)
Syllabus:
Unit II : Design Fundamentals
Design: Steps in design process, Mechanical Properties (Strength, Toughness, Hardness,
Ductility, Malleability, Brittleness, Elasticity, Plasticity, Resilience, Fatigue, Creep) and
selection of Engineering materials.
Applications of following materials in engineering - Aluminum, Plastic, Steel, Brass, Cast
Iron, Copper, Rubber Mechanism (Descriptive treatment only): Definition and
comparison of Mechanism and Machine, Four Bar Mechanism, Slider Crank Mechanism.
Reference Book – Design of Machine Elements by V. B. Bhandari
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5. 102013 - Basic Mechanical Engineering (2012 Pattern)
Syllabus:
Unit III : Manufacturing Processes
Introduction to Manufacturing Processes and their Applications (Casting, Forging,
Sheet metal working and Metal joining processes). Description of the Casting process:
Sand casting (Cope & Drag), Sheet metal Forming (shearing, bending, drawing), Forging
(Hot working and cold working comparison), Electric Arc welding, Comparison of—
Welding, Soldering, Brazing.
Reference Book – Manufacturing Processes by Hajara Chaudhari (Vol I)
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6. 102013 - Basic Mechanical Engineering (2012 Pattern)
Syllabus:
Unit IV : Machine Tools
Basic Elements, Working Principle, Types of Operations with block diagram:
Lathe Machine - Centre Lathe,
Drilling Machines,
Grinding Machines.
Reference Book – Manufacturing Processes by Hajara Chaudhari (Vol II)
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7. 102013 - Basic Mechanical Engineering (2012 Pattern)
Syllabus:
Unit V : Thermal Engineering
Thermodynamics: Thermodynamics system (open, close, and isolated), Thermodynamic
Properties: Definition & Units of -Temperature, Pressure (atmospheric, absolute &
gauge). Volume. Internal energy, Enthalpy, Concept of Mechanical work,
Thermodynamics Laws with example- Zeroth Law, First Law, Limitations of first law.
Concept of heat Sink. Source, heat engine, heat pump, refrigeration engine. 2nd
Law of Thermodynamics statements, Numerical on 2nd law only.
Measurement: Measurement of Temperature (Thermocouple - Type according to
temperature range and application), Measurement of Pressure (Barometer, Bourdon
pressure gauge, Simple U tube Manometer with numerical).
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8. 102013 - Basic Mechanical Engineering (2012 Pattern)
Syllabus:
Unit VI : Applied Thermal Engineering
Power Plant Engineering: Conventional and non-conventional energy resources, Hydro-
electric, Thermal, Nuclear. Wind, Solar [with Block diagram].
Power Producing Devices: Boiler - Water tube and lire tube. Internal combustion engine
- Two stroke and four stroke (Spark ignition and compression ignition). Turbines -
Impulse and reaction.
Power Absorbing Devices: Pump - Reciprocating and Centrifugal, Compressor - Single
acting, single stage reciprocating air compressor, Refrigeration - Vapour compression
refrigeration process, House hold refrigerator. Window air conditioner (Working with
block diagrams).
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9. 102013 - Basic Mechanical Engineering (2012 Pattern)
Term work :
Term work consist of the following:
1. Study of power transmitting elements: couplings, gears and bearings.
2. Study of mechanisms: (bur bar mechanism, slider crank mechanism
3. Study, demonstration and working of center lathe machine
4. Study of any one power plant
5. Study, demonstration on two stroke and four stroke engine.
6. Study, domestic refrigerator and window air conditioner.
7. Study of Package Type Boiler.
8. Report on visit or guest lecture related to mechanical engineering.
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10. 102013 - Basic Mechanical Engineering (2012 Pattern)
Marking Scheme :
• Online Test: 50 Marks
• Online Test 1 (Phase I) : 30 Minutes Examination, 25 Marks
• Online Test 2 (Phase II) : 30 Minutes Examination, 25 Marks
• Theory Paper (Phase III) : 120 Minutes Examination, 50 Marks
• Term-work: 25 marks
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11. Mechanical
It is the branch of engineering
that involves the design,
production, and operation of
machinery.
Engineering
The action of
working artfully to
bring something
about.
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12. What is Mechanical Engineering?
• Technically, mechanical engineering is the application of the principles and
problem solving techniques of engineering from design to manufacturing to the
marketplace for any object.
• Mechanical engineer analyze their work using the principles of motion, energy
and force – ensuring that designs function safely, efficiently and reliably, all at a
competitive cost.
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13. What does a Mechanical Engineer do?
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14. What is Machine?
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15. What is Machine?
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16. What is Machine?
Input (Source of Energy)
Machine (Set of Elements)
Output (Product)
• A device consisting of fixed and moving parts that modifies mechanical energy and
transmits it in a more useful form.
• A piece of equipment with several moving parts that uses power to do
particular type of work:
Definition:
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17. • The different sizes of eggs are sorted by a machine.
• If I'm not home when you call, leave a message on the
machine (= answering machine).
• Don't forget to put the towels in the machine (= washing machine)before you go out.
• I got some chocolate from a vending machine.
• Doctors kept him alive on a life-support machine.
• There is a vending machine on the platform that dispenses snacks.
• The machine emits a high-pitched sound when you press the button.
• This sewing machine is operated by a foot pedal.
• I need some coins for the ticket machine in the car park.
• You'll need a powerful machine for editing videos.
• Tungsten carbide tools are used extensively for machining steel.
Examples:
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18. Think of Machine modification.. Simple but innovative
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19. Think of Machine modification.. Simple but innovative
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20. Think of Machine modification.. Simple but innovative
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21. Think of Machine modification.. Simple but innovative
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22. MCQ:
1. Machine is capable of:
a) Creating energy
b) Creating and transforming energy
c) Transforming and transferring energy
d) Creating, transforming and transferring energy
Hint: A Machine is capable of doing some useful work. It converts and transfers energy
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23. MCQ:
2. The device which receives an energy and convert it into useful work is
known as
a) Machine
b) Mechanism
c) Electric motor
d) Both a and b
Hint: A Machine is capable of receiving, converting, transforming and transferring energy
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24. MCQ:
3. The machine that converts electrical energy to mechanical energy and
finally hydraulic energy is
a) Hydraulic turbine
b) Pump set
c) Hydraulic motor
d) Both a and b
Hint: A Machine which induce flow or raise pressure of a liquid
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25. Machine Elements
• Machine elements are basic mechanical parts and features used as
the building blocks of most machines
• Machine elements is an individual part or component of machine
which perform a specific task
Think of Screw Jack
and list out its
Elements
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26. Think of Screw Jack and list
out its Elements
Handle
Screw
Nut
Body
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27. Functions of Machine Elements
• Holding the different components of the machine
• Supporting the different components of the machine
• Transmitting the power from one component to the another component
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28. Holding type Elements
Keys
Nuts and Bolts
Cotters
Rivets
Couplings
Supporting type
Elements
Axles
Bearings
Brackets
Body or Frame
Power Transmitting
Elements
Shafts
Pulleys and Belts
Sprockets and
Chains
Gears
Clutches
Types (Classification) of Machine Elements
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29. Holding type elements
• The holding type elements are used for holding the different components of
machine.
• Example: Keys, Nut and bolts, Rivets etc….
Supporting type elements
• The supporting type elements are use for supporting different
components of machine
• Examples: Axles, Bearings Body frames etc….
Power transmitting Elements
• The power transmitting elements are use for transmitting the power from one
component to another component of the machine
• Examples: Shafts, Pulleys, belts etc….
By: Nitin Shekapure
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30. MCQ:
4. The individual part of a machine which performs a specific task is
known as
a) System
b) Mechanism
c) Machine element
d) Body
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31. MCQ:
5. Which of the following is not a function of machine element?
a) Holding the different components of machine
b) Supporting the different components of machine
c) Modifying the different components of machine
d) Transmitting the power
Hint:
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32. MCQ:
6. The following is not an example of holding type element
a) Gear
b) Key
c) Cotter
d) Rivet
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33. MCQ:
7. The following is not a power transmitting element
a) Bearing
b) Shaft
c) Gear
d) Belt
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34. MCQ:
8. The following machine element can not be use for power transmission
a) Belt
b) Axle
c) Shaft
d) All above
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35. MCQ:
9. The example of holding type element is
a) Bearing
b) Gear
c) Shaft
d) Rivet
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36. MCQ:
10. The example of supporting type element is
a) Bearing
b) Gear
c) key
d) Cotter
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37. MCQ:
11. Find the odd machine element from the following
a) Axle
b) Bearing
c) Shaft
d) Bracket
Explanation: Axle, Bearing and Bracket are supporting type of elements. While shaft is a
power transmitting element
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38. MCQ:
12. Find the odd machine element from the following
a) Axle
b) Chain
c) Shaft
d) Belt
Explanation: Chain, Shaft and Belt are power transmitting element. While Axle is a
supporting type element
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39. Shafts
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40. Shafts
A shaft is a rotating machine element, usually circular in cross section, which is used
to transmit power from one part to another, or from a machine which produces
power to a machine which absorbs power. The various members such
as pulleys and gears are mounted on it.
In order to transmit the power from one shaft to another, the various members such
as: gear, pulleys, sprockets, etc. are mounted on it.
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41. Functions of Shaft
The shaft performs the following functions
• To transmit the power or motion.
• To support the power transmitting elements like: gears, pulleys, coupling etc.
Types of Shaft
They are mainly classified into two types.
• Transmission shaft
• Machine Shaft
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42. Types of Shaft
Transmission shaft:
• Transmission shafts are used to transmit power between the source and the
machine absorbing power.
Example: Counter shafts and Line shafts.
• The transmission shaft supports transmission elements like : gears, pulleys,
sprockets etc.
• The transmission shafts are subjected to torque,
bending moment, and/or axial force.
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43. Line shaft:
• A shaft connected to a prime mover which transmits power to a number
of machines
• Line shafts is a transmission shaft which is directly driven by the prime
mover (Power source) and from which the power is supplied to the
different machines.
• Line shaft is directly connected to prime mover (Power source)
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44. Counter shaft:
• Counter shaft is a secondary shaft which is driven by the main shaft
through belt, chain or gear drive and from which the power is supplied to
the different machines.
• Counter shaft is not directly connected to prime mover (Power source)
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45. • Jackshaft:
A jackshaft, also called a countershaft, is a common mechanical design component used
to transfer or synchronize rotational force in a machine. A jackshaft is often just a short
stub with supporting bearings on the ends and two pulleys, gears, or cranks attached to
it.
A short intermediate shaft on which two pulleys or gears or sprockets are mounted to
change the speed within the transmission system.
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46. • Machine shaft:
Machine shafts are the integral part of the machine itself.
Example: Crankshaft and spindle
Similar to transmission shafts, Machine shaft are also subjected to torque,
ending moment, and/or axial force.
• Crankshaft: The shaft which used in multi cylinder IC engine to which cranks are
embedded is called crankshaft.
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47. Spindle: Spindle is peculiar terminology associated with shafts of machine tools which
provide rotary motion either to a cutting tool or to a work piece.
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48. Shaft Materials and their desirable properties
The material used for ordinary shafts is mild steel. When high strength is
required, an alloy steel such as nickel, nickel-chromium or chromium-
vanadium steel is used.
The brittle material like cast iron can not be use for shaft manufacturing.
Shafts are generally formed by hot rolling and finished to size by cold
drawing or turning and grinding.
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49. Shaft Materials and their desirable properties
The material use for shaft should posses the following properties
• It should have high static strength
• It should have high fatigue strength
• It should be ductile
• It should have high resilience
• It should have good machinability
Static strength is to exert force on an object you cannot move
Fatigue is the weakening of a material caused by repeatedly applied loads
Ductility is a solid material's ability to deform under tensile stress
Resilience is the ability of a material to absorb energy when it is deformed elastically, and
release that energy upon unloading.
The term machinability refers to the ease with which a metal can be cut (machined)
permitting the removal of the material with a satisfactory finish at low cost
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50. Axle
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51. Axle
The axle is a non rotating bar which doesn’t transmit any torque but only used to
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52. Difference between Axle and Shaft
Axle Shaft
Axle is a non rotating member Shaft is rotating member
Primary function is to provide support to
elements like wheel, pulley etc.
Primary function is to transmit torque.
Axle is subjected to bending moment
and/or axial force
Shaft is subjected to bending moment,
axial force, as well as torsional moment
(torque)
Depending upon loading condition, cross
sectional area of axle can be different e. g.
Rectangular, Circular, I-section, T-section
etc.
Cross sectional area of shaft is generally
circular because it causes minimum
vibrations and peaking of torsional stress.
(For a given cross section area circular
shape provides minimum peak stress under
same torsional loading.)
Examples: Axles of automobiles, railway
buggies.
Examples: Shaft of electric motor, shaft of
IC engine
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53. More understanding about Shaft and Axle
Axles are rotating or non-rotating members which are subjected to only bending
moments due to members supported by it. It does not transmit torque.
In other words, an axle is not twisted it only bends.
Shafts are rotating members which are subjected to bending moments and twisting
moments and sometimes to axial loads. It twists and transmits power.
The basic difference lies in the power transmission capability...
If the power is transmitted from one part or the other through a rotating rod in between,
it is called a shaft.. On the other hand, axle is a static part, attached to output as a joint.
Shaft is a live member while Axle is dead one!!
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54. Ideally speaking Axles are meant for balancing/transferring Bending moment and Shafts
are meant for Balancing/transferring Torque. But, they can be used interchangeably also.
We can have a shaft which also transmits Torque as well as Balances bending moment and
in the same way an axle can also function as shaft. Such machine elements which function
as axle as well as shaft are called Axle shafts. Axle shafts are designed while taking care of
the acting Bending Moment as well as Torque. Ideally speaking Axles are meant for
balancing/transferring Bending moment and Shafts are meant for Balancing/transferring
Torque. But, they can be used interchangeably also. We can have a shaft which also
transmits Torque as well as Balances bending moment and in the same way an axle can
also function as shaft. Such machine elements which function as axle as well as shaft are
called Axle shafts. Axle shafts are designed while taking care of the acting Bending
Moment as well as Torque.
More understanding about Shaft and Axle
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55. MCQ:
13. A Shaft is a
a) Stationary member used to transmit power and motion
b) Rotating member use to transmit power
c) Horizontal member used to support gears and pulleys
d) Horizontal member used to support machines
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56. MCQ:
14. Shaft are classified as
a) Transmission shaft, machine shaft and axles
b) Transmission shaft & machine shaft
c) Counter shafts and crank shafts
d) Line shafts and spindles
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57. MCQ:
15. Shaft cannot be made of:
a) Plane carbon steel
b) Allow steel
c) Cast iron
d) Both b and c
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58. MCQ:
16. The example of machine Shaft is,
a) Line shaft
b) Counter shaft
c) Spindle
d) All above
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59. MCQ:
17. Which of the following shaft is not directly connected to prime mover.
a) Line shaft
b) Counter shaft
c) Spindle
d) Both b and c
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60. MCQ:
18. Which of the following shaft is used for transmitting the power to
more than one machine
a) Crank shaft
b) Counter shaft
c) Spindle
d) All above
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61. MCQ:
19. The following property is undesirable for shaft
a) Ductility
b) Brittleness
c) Resilience
d) Fatigue strength
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62. MCQ:
20. The shaft A shown in figure is a ______
a) Counter Shaft
b) lay shaft
c) Line shaft
d) Both a and b
Shaft A
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63. MCQ:
20. Following is a rotating element used for transmitting power from one
element to other
a) Shaft
b) Axle
c) Rod
d) Both a and b
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64. MCQ:
21. A non-rotating machine element which is used to support rotating
machine elements like wheels, pulley, etc. is know as
a) Shaft
b) Spindle
c) Axle
d) Bracket
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65. MCQ:
22. The following is not an example of machine shaft
a) spindle
b) Crankshaft
c) Transmission shaft
d) Both b and c
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66. MCQ:
23. Following is a rotating element used for transmitting power from one
element to other
a) Shaft
b) Axle
c) Rod
d) Both a and b
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67. MCQ:
24. Axle is subjected to
a) Torque
b) Bending moment
c) Axial force
d) b and/or c
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68. MCQ:
25. The shaft directly connected to the power source is called as ______
a) Line shaft
b) Counter shaft
c) Both a and b
d) None of the above
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69. MCQ:
26. Which of the following statements is/are true?
a) Axles are used to transmit power
b) Shafts and axles are rotating elements
c) Shafts transmit power while axles do not transmit power
d) All of the above
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70. Key
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71. • A key is a machine element used to connect a rotating machine element to
a shaft. The key prevents relative rotation between the two parts and may
enable torque transmission.
• For a key to function, the shaft and rotating machine element must have
a keyway and a keyseat, which is a slot and pocket in which the key fits. The
whole system is called a keyed joint.
Mechanical Keys
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72. Key: It is defined as a piece of metal which is used to connect a shaft and hub or
sleeve
• Basically Key is a temporary joint or connection like nut and bolt
• Keys are subjected to sharing and crushing
• The material use for shaft and key is same
Functions of Keys
• Used to prevent the relative motion between the shaft and the hub of
rotating element like : gear, pulley, or sprocket.
• To transmit the torque from the shaft to the rotating element or vice-versa.
By: Nitin Shekapure
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73. Types of Keys
Keys
Sunk Key
Rectangular Key
Square Key
Parallel Key
Gib-head Key
Woodruff Key
Feather Key
Saddle key
Tangent Key
Round Key
Spline Key
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74. Sunk Keys
Sunk keys are keys whose one half is in the key way of the shaft and the other
half is in the key way of the hub of the rotating element
Rectangular Sunk keys are keys whose width and height are not equal.
Square Sunk keys are keys whose width and height are equal.
Parallel Sunk Keys are taperless key having a rectangular or square cross-
section. It is used when the rotating element is required to slide alone the shaft
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75. Rectangular Sunk keys are keys whose width and height are not equal.
Square Sunk keys are keys whose width and height are equal.
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76. Parallel Sunk Keys are taperless key having a rectangular or square cross-section.
It is used when the rotating element is required to slide alone the shaft.
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77. Gib head Keys are rectangular keys with a head at one end know as Gib-Head.
It is usually provided to facilitate the removal of key.
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78. Feather Keys are parallel keys with are fixed to either to the Shaft or Hub. It permits
Relative Axial Movement between the shaft and hub and prevents Relative Rotational
Movement between them.
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79. Woodruff Keys is a segment from a Cylindrical Disc. The Keyway in the shaft is in
the form of a Semicircular Recess with the Same Curvature as that of the Key.
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80. Saddle Keys are keys that fit in the Hub only, as there is no Keyway on the Shaft.
By: Nitin Shekapure
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81. Flat Saddle Keys have a Flat Surface at the Bottom. It sits on the Flat surface
machined on the Shaft.
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82. Hollow Saddle Keys have a Concave Surface at the Bottom to match the Circular
Surface of the Shaft.
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83. Tangent Keys are fitted in pair at Right Angles for mating bodies of Rectangular
Cross-Section.
By: Nitin Shekapure
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84. Round Keys are Circular in Section and fit in to holes drilled partly in the Shaft and
partly in the Hub.
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85. Splines are In-built Keys which are formed by shaping the Outer Circumference of the
Shaft and the Inner Circumference of the Hub with Tooth Like Structure.
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86. Kennedy Keys consists of Two Square Keys which are mounted in the Shaft.
By: Nitin Shekapure
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87. Rectangular Key
•Width of Key, w = d/4 & Height, h = 2/3*w, where, d=
diameter of shaft
•Used in mounting of flanges, pulleys, gears, etc. on shaft
Square Key
•Height = width of key = d/4, where, d= diameter of shaft
•Used in mounting of flanges, pulleys, gears, etc. on shaft
Parallel Key
•Parallel key may be rectangular or square cross-section and
is taper less.
•Used in gear boxes, where spacers are used to restrict the
axial movement of rotating element
Salient Features and Applications of Keys
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88. Gib-Headed Key
•The gib-head is provided to facilitate the removal of key
•Used for mounting the rotating element like – Flywheels, pulleys,
gears etc., on overhanging end of the shaft where one end of key
seat is inaccessible.
Feather Key
•Feather key prevents the relative rotary motion, but permits the
relative axial motion between the shaft and hub
•Used in clutches and gear shifting devices where rotating
elements mounted on the shaft are required to slide alone the
shaft.
Woodruff Key
•Woodruff key is a segment from the cylindrical disc.
•Suitable for tapered shafts
•Used in machine tools and automobiles
Salient Features and Applications of Keys
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89. MCQ:
27. The function of key is,
a) To prevent the relative motion between the shaft and the hub of rotating
element.
b) To fix bearing on shaft.
c) To fix bearing on shaft.
d) Both a and b
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90. MCQ:
28. Key is used on shaft to secure
a) Rolling contact bearing
b) Sliding contact bearing
c) Gear
d) All above
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91. MCQ:
29. Key is generally made of
a) Steel
b) Cast iron
c) Aluminum
d) B and c
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92. MCQ:
30. Which of the following statement is correct
a) Shaft is made of weaker material.
b) Key is made of weaker material.
c) Shaft and key are made of weaker material.
d) Shaft and key are made of stronger material.
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93. MCQ:
31. The most widely used type of sunk key is
a) Saddle Key
b) Round Key
c) Rectangular Key
d) Tangent Key
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94. MCQ:
32. Rectangular key is a type of
a) Square key
b) Woodruff key
c) Saddle key
d) None of the above
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95. MCQ:
33. Square key is a type of
a) Sunk key
b) Woodruff key
c) Saddle key
d) None of the above
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96. MCQ:
34. If the key is half in key-way of the shaft and half in the key-way of the
hub of the rotating element, then it must be a
a) Sunk key
b) Splines
c) Saddle key
d) None of the above
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97. MCQ:
35. Which of the following keys is suitable for taper shafts?
a) Woodruff key
b) Splines
c) Tangent key
d) None of the above
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Shekapure

98. MCQ:
36. The key shown in the figure is a
a) Saddle key
b) Sunk Key
c) Gib key
d) None of the above
N
itin
Shekapure

99. MCQ:
37. The key shown in the figure is a
a) Taper key
b) Gib-headed Key
c) Saddle key
d) None of the above
N
itin
Shekapure

100. MCQ:
38. The key that weaken the shaft is
a) Woodruff key
b) Rectangular key
c) Tangent key
d) Saddle key
N
itin
Shekapure

101. MCQ:
39. Which of the following is a parallel key
a) Feather key
b) Gib-headed key
c) Rectangular key
d) Woodruff key
N
itin
Shekapure

102. MCQ:
40. The key that permits axial motion between shaft and hub is called as
a) Feather key
b) Gib-headed key
c) Rectangular key
d) Splines
N
itin
Shekapure

103. MCQ:
41. The multiple key also know as
a) Feather key
b) Gib-headed key
c) Rectangular key
d) Splines
N
itin
Shekapure

104. MCQ:
42. The following type of key is used in automobile gear boxes:
a) Feather key
b) Kennedy key
c) Tangent key
d) Splines
N
itin
Shekapure

105. MCQ:
43. The Spline are
a) Integral with hub
b) Integral with shaft
c) Integral with both hub and shaft
d) A and b
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Shekapure

106. Coupling
By: Nitin Shekapure
N
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Shekapure

107. The term coupling refers to a device used to connect two shafts
together at their ends for the purpose of transmitting power.
Couplings do not normally allow disconnection of shafts during
operation, however there are torque limiting couplings which can slip
or disconnect when some torque limit is exceeded.
Coupling
The primary purpose of couplings is to join two pieces of
rotating equipment while permitting some degree of
misalignment or end movement or both. By careful selection,
installation and maintenance of couplings, substantial savings
can be made in reduced maintenance costs and downtime.
N
itin
Shekapure

108. Couplings are used in machinery for several purposes.
• To transfer power one end to another end.(ex: motor transfer power to
pump through coupling) Primary function.
• To provide for the connection of shafts of units that are manufactured
separately such as a motor and generator and to provide for disconnection
for repairs or alterations.
• To provide for misalignment of the shafts or to introduce mechanical
flexibility.
• To reduce the transmission of shock loads from one shaft to another.
• To introduce protection against overloads.
• To alter the vibration characteristics of rotating units.
• To connect driving and the driven part
• Slips when overload occurs
N
itin
Shekapure

109. Couplings
Rigid
Sleeve or
Muff
Clamp or Split
Muff or
Compression
Flange
Un-
Protected
type
Protected
type
Flexible
Bushed –
Pin
Universal Oldham
Types of Coupling
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Shekapure

110. Used to connect two shaft
having no misalignment.
Used to connect two shaft
having some amount of
misalignment.
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Shekapure

111. Rigid Coupling
• Rigid couplings are used when precise shaft alignment is required
• Rigid coupling has no flexibility
• Simple in construction and less expensive
By: Nitin Shekapure
N
itin
Shekapure

112. Flexible Coupling
• Flexible couplings are used to transmit torque from one shaft to
another when the two shafts are slightly misaligned.
• Flexible couplings can accommodate varying degrees of
misalignment up to 3° and some parallel misalignment.
• In addition, they can also be used for vibration damping or noise
reduction.
• This coupling is used to protect the driving and driven shaft
members against harmful effects produced due to misalignment of
the shafts, sudden shock loads, shaft expansion or vibrations etc.
N
itin
Shekapure

113. Sleeve or Muff Coupling
A sleeve coupling consists of a pipe whose bore is finished to the required
tolerance based on the shaft size. Based on the usage of the coupling
a keyway is made in the bore in order to transmit the torque by means of the
key. Two threaded holes are provided in order to lock the coupling in
position.
• This is the simplest type of the coupling.
• It is made from the cast iron and very simple to design and manufacture.
• It consists of a hollow pipe whose inner diameter is same as diameter of
the shafts.
• The hollow pipe is fitted over a two or more ends of the shafts with the
help of the taper sunk key.
• A key and sleeve are useful to transmit power from one shaft to another
shaft.
N
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Shekapure

114. Clamp or Split Muff or Compression Coupling
• In this coupling, the muff or sleeve is made into two halves parts of the
cast iron and they are joined together by means of mild steel studs or
bolts. T
• he advantages of this coupling is that assembling or disassembling of the
coupling is possible without changing the position of the shaft.
• This coupling is used for heavy power transmission at moderate speed.
N
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Shekapure

115. Flange Coupling
Flange Coupling consist of two flanges which are keyed to the
shaft and bolted. The bolts are equi-spaced. Number of bolts used
are generally three, four or six.
Flanged rigid couplings are designed for heavy loads or industrial
equipment.
The flanges are made of cast iron, cast steel or steel
Flange coupling is widely used rigid coupling
Application: used in Pump or
compressor
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Shekapure

116. • This is used for slightly imperfect alignment of the two shafts.
• This is modified form of the protected type flange coupling. This type of
coupling has pins and it works with coupling bolts.
• The rubber or leather bushes are used over the pins.
• The coupling has two halves dissimilar in construction.
• The pins are rigidly fastened by nuts to one of the flange and kept loose on
the other flange.
• This coupling is used to connect shafts which having a small parallel
misalignment, angular misalignment or axial misalignment.
• In this coupling the rubber bushing absorbs shocks and vibration during its
operations.
• This type of coupling is mostly used to couple electric motors and machines.
Bushed-pin Coupling
By: Nitin Shekapure
N
itin
Shekapure

117. Universal Coupling
Universal Coupling consist of two forks keyed or screwed to the shaft
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Shekapure

118. Oldham Coupling
An Oldham coupling has two flanges and one discs, one flange is coupled to the
input, one coupled to the output, and a middle disc that is joined to the first two
by tongue and groove.
An advantage to this type of coupling, as compared to two universal joints, is its
compact size.
N
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Shekapure

119. Parameters Rigid Coupling Flexible Coupling
Purpose
Used to connect two shafts
which are perfectly aligned
Used to connect two
shafts having small
misalignment
Alignment
Cannot tolerate
misalignment between two
shafts
Tolerate small
misalignment between
two shafts
Shock and
Vibrations
Cannot absorb Shock and
Vibrations
Can absorb Shock and
Vibrations
Deflection Shaft deflection is less Shaft deflection is more
Cost Low High
Comparison between Rigid and Flexible Coupling
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Shekapure

120. Couplings
Rigid
Sleeve or Muff
Clamp or Split Muff or
Compression
Flange
Flexible
Bushed – Pin
Universal
Oldham
Used for line shaft
Used for line shaft
Used for connecting electric
motor to pump or
compressor
Used for connecting diesel
engine to generator
Used for connecting two
electric shafts
Used between gear box
and differential of
automobile
Application/use
N
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Shekapure

121. MCQ:
44. Coupling is used for
a) Connecting two axles
b) Connecting two transmission shafts
c) Connecting axle with shaft
d) Both b and c
N
itin
Shekapure

122. MCQ:
45. Coupling is used to connect two
a) Axles
b) Shafts
c) Rods
d) All above
N
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Shekapure

123. MCQ:
46. The flange coupling transmits
a) Torque
b) Torque and axial force
c) Torque, axial force and bending moment
d) Axial force
N
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Shekapure

124. MCQ:
47. The _________ is a type of rigid coupling.
a) Flange coupling
b) Universal coupling
c) Oldham’s coupling
d) None of the above
N
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Shekapure

125. MCQ:
48. Coupling is used for transmitting
a) Torque from one axle to another.
b) Force from one shaft to another.
c) Bending moment from one shaft to another.
d) None of the above
Explanation : Coupling is used for transmitting the torque from one shaft to another.
N
itin
Shekapure

126. MCQ:
49. Which of the following is not a rigid coupling ?
a) Oldham coupling
b) Muff coupling
c) Clamp coupling
d) Flange coupling
N
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Shekapure

127. MCQ:
50. Which of the following statements is incorrect ?
a) Rigid couplings are used to connect two shafts which are perfectly aligned
b) Rigid couplings are capable of tolerating misalignment between two shafts
c) Rigid couplings are used for transmitting the torque
d) Rigid coupling facilitates easy connection and disconnection between two
shafts
N
itin
Shekapure

128. MCQ:
51. Couplings are used to connect two shafts which are
a) Perfectly aligned
b) Having small amount of lateral misalignment
c) Having small amount of angular misalignment
d) All of the above
Explanation : Rigid coupling are used to connect two shafts which are perfectly
aligned, while flexible couplings are used to connect two shafts which are having
small amount of lateral or/and angular misalignment
N
itin
Shekapure

129. MCQ:
52. The following type of coupling is used for connecting two shafts having
small amount of misalignment
a) Rigid flange coupling
b) Muff coupling
c) Split-muff coupling
d) None of the above
Explanation : All couplings mentioned above are rigid couplings and are suitable
only to connect the two shafts which are perfectly aligned.
N
itin
Shekapure

130. MCQ:
53. The following type of coupling is suitable for connecting two shafts
which are perfectly aligned as well as connecting two shafts having
small amount of misalignment:
a) Bushed-pin type coupling
b) Rigid flange coupling
c) Split-muff coupling
d) None of the above
Explanation : Bushed-pin type coupling is a flexible coupling, and hence suitable for
connecting perfectly aligned shafts as well as shafts having small amount of
misalignment.
N
itin
Shekapure

131. MCQ:
54. The ________ couplings are used to connect two shafts which are
perfectly aligned.
a) Universal
b) Rigid
c) Oldham
d) All above
N
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Shekapure

132. MCQ:
55. The _________ is not capable of absorbing shocks and vibrations.
a) Flange coupling
b) Muff coupling
c) Split-muff coupling
d) All above
N
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Shekapure

133. MCQ:
56. __________ is not a type of coupling
a) Muff coupling
b) Compression coupling
c) Shaft coupling
d) Clamp coupling
Explanation : There is nothing like shaft coupling. Remaining are types of rigidcouplings.
N
itin
Shekapure

134. MCQ:
57. The number of bolts used in flange coupling can be.
a) 3
b) 5
c) 7
d) 2
N
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Shekapure

135. MCQ:
58. The number of bolts used in flange coupling are.
a) 3
b) 4
c) 6
d) All the above
N
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Shekapure

136. MCQ:
59. In flange coupling, the two flanges are connected together by.
a) Screw
b) Nut and bolts
c) Key
d) All the above
N
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Shekapure

137. MCQ:
60. The number of keys used in flange coupling are
a) 1
b) 2
c) 3
d) 4
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Shekapure

138. MCQ:
61. In rigid flange coupling, the torque is transmitted from the driving
shaft to the driven shaft.
a) Directly
b) Through flanges
c) Through key-flanges-bolts-key
d) Keys
N
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Shekapure

139. MCQ:
62. The appropriate application of rigid flange coupling is:
a) Connecting diesel engine to generator
b) Connecting electric motor to centrifugal pump
c) Connecting gear box to differential of automobile
d) Keys Connecting diesel engine to stone crusher
N
itin
Shekapure

140. MCQ:
63. In rigid flange coupling, the following component can be made of cast
a) Shaft
b) Flanges
c) Bolts
d) Keys
N
itin
Shekapure