Types of Dynamometers - Theory of Machine

1. DYNAMOMETERS
(Theory of Machine – I)
Prepared By
Prof. D. S. Dabhade
Department of Mechanical Engineering
MGM’S Jawaharlal Nehru Engineering College ,Aurangabad

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Dynamometer –
It is a device to measure frictional resistance.
- Torque transmitted , Power of Engine
Types of Dynamometers
1. Absorption Dynamometers
i . Prony Brake Dynamometer
ii . Rope Brake Dynamometer
2. Transmission Dynamometers
i. Epicyclic train dynamometer
ii. Belt transmission dynamometer
iii. Torsion dynamometer
Prof. D.S.DABHADE ,
Department of Mechanical Engineering ,
MGM’S J. N. E. C, Aurangabad

3. 3
Absorption Dynamometers
During Process of Measurement…
 Total Power / Energy Produced is absorbed by
frictional resistance
 Transformed in to Heat
Prof. D.S.DABHADE ,
Department of Mechanical Engineering ,
MGM’S J. N. E. C, Aurangabad

4. 1. Prony Brake Dynamometer
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 Load the lever end with suitable weight W
 Nuts are tightened until –
Engine shaft runs at constant speed and
Lever is in horizontal position.
 Under these condition must satisfy …
Moment due to Weight W = Moment due to Frictional Resistance
Prof. D.S.DABHADE ,
Department of Mechanical Engineering ,
MGM’S J. N. E. C, Aurangabad

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Prof. D.S.DABHADE ,
Department of Mechanical Engineering ,
MGM’S J. N. E. C, Aurangabad

6. 2. Rope Brake Dynamometer
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 Engine runs at a constant speed
 Under these condition must satisfy …
Frictional torque due to rope = Torque transmitted by engine
Prof. D.S.DABHADE ,
Department of Mechanical Engineering ,
MGM’S J. N. E. C, Aurangabad

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Prof. D.S.DABHADE ,
Department of Mechanical Engineering ,
MGM’S J. N. E. C, Aurangabad

8. TranTransmission Dynamometers
- During Process of Measurement…
 Energy is utilized for work done
 Energy/ Power developed by engine is transmitted through
dynamometer to other machine.
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Prof. D.S.DABHADE ,
Department of Mechanical Engineering ,
MGM’S J. N. E. C, Aurangabad

9. 1. Epicyclic train dynamometer
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 Friction of pin on which pinion rotates is neglected
 Tangential effort P exerted by spur on pinion and tangential reaction of
annular gear on pinion are equal
 Total upward force on lever = 2P
Tends to rotate the lever about fulcrum
Balanced by a dead wt W at end of lever
Prof. D.S.DABHADE ,
Department of Mechanical Engineering ,
MGM’S J. N. E. C, Aurangabad

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Prof. D.S.DABHADE ,
Department of Mechanical Engineering ,
MGM’S J. N. E. C, Aurangabad

11. 2. Belt transmission dynamometer
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Prof. D.S.DABHADE ,
Department of Mechanical Engineering ,
MGM’S J. N. E. C, Aurangabad

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Prof. D.S.DABHADE ,
Department of Mechanical Engineering ,
MGM’S J. N. E. C, Aurangabad

13. 3. Torsion Dynamometer
When power transmitted…
 Driving end of shaft twist through small angle relative to driven
 Amount of twist depends upon factors…
i. Torque acting on shaft (T)
ii. Length of Shaft (L)
iii. Diameter of Shaft (D)
iv. Modulus of Rigidity (C)
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Prof. D.S.DABHADE ,
Department of Mechanical Engineering ,
MGM’S J. N. E. C, Aurangabad

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We Know that
Prof. D.S.DABHADE ,
Department of Mechanical Engineering ,
MGM’S J. N. E. C, Aurangabad

15. Thank You…
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