Rope brake dynamometer

A

Mini Project Report

On

“ROPE BRAKE DYNAMOMETER”

Submitted to

Rashtrasant Tukadoji Maharaj Nagpur University, Nagpur

In Partial Fulfillment of Bachelor of Engineering

Submitted By

Purvansh B. Vaikunthe (48/B) Saket P. Kolhe (50/B)

Pranav R. Padole (47/B) Neeraj K. Chaudhary (42/B)

Piyush C. Piprikar (46/B) Shaunak S. Kulkarni

Under the Guidance of

Prof. Milind P. Kshirsagar

Department of Mechanical Engineering St. Vincent Pallotti College of Engineering & Technology,

Wardha Road, Nagpur (2013-14)

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Department of Mechanical Engineering, St. Vincent Pallotti College of Engineering & Technology,

Wardha Road, Nagpur

CERTIFICATE This is to certify that the Mini Project entitled “ROPE BRAKE DYNAMOMETER”

has been successfully completed by Purvansh Vaikunthe, Saket Kolhe, Pranav Padole,

NeerajKumar Chaudhary, Piyush Piprikar, Shaunak Kulkarni students of 4th semester

B.E. for the partial fulfillment of the requirements for the Bachelors degree in Mechanical

Engineering of the St. Vincent Pallotti College of Engineering & Technology during the

academic year 2013-14

Guide : Prof. Milind P Kshirsagar Prof. A. D. Pachchhao Designation: Asst. Professor. Head of the Department Mechanical Engineering. Dept of Mechanical Engineering SVPCET, Nagpur SVPCET, Nagpur

ROPE BRAKE DYNAMOMETER

Department of Mechanical Engineering, SVPCET 2013-2014 i

ACKNOWLEDGEMENT

I am grateful to my respected guide Prof. Milind P Kshirsagar for his kind, disciplined

and invaluable guidance which inspired me to solve all the difficulties that came across during

completion of the project.

I express my special thanks to Prof. A.D. Pachchhao, Head of the Department, for his

kind support, valuable suggestions and allowing me to use all facilities that are available in the

Department during this project. My sincere thanks are due to Pachchhao Sir, H.O.D., for

extending the all possible help and allowing me to use all resources that are available in the

Institute.

I would like to thanks all the faculty members of Mechanical Engineering Department for

their support, for the successful completion of this project work. The acknowledgement shall

remain incomplete without expressing my warm gratitude to the almighty God.

I would also like to thanks all my Family members and Friends for their continues

support and standing with me in all difficult condition during this work.

Purvansh B. Vaikunthe (48/B)

Saket P. Kolhe (50/B)

Pranav R. Padole (47/B)

Neeraj K. Chaudhary (42/B)

Piyush C. Piprikar (46/B)

Shaunak S. Kulkarni


Department of Mechanical Engineering, SVPCET 2013-2014 ii

INDEX

CHAPTER

NO.

PARTICULARS PAGE NO.

Acknowledgement

List of figures

List of tables

Symbol used

ABSTRACT

i

iii

iv

v

vi

I 1. INTRODUCTION

1.1 Definition of Dynamometer

1.2 Types of Dynamometer

1.3 Absorption Dynamometer

1.4 Transmission Dynamometer

1.5 Theory of Dynamometer

1

2

2

2

3

3

II 2. LITERATURE SURVEY 5

III 3. WORKING PRINCIPLE

3.1 Parts of a Rope Brake Dynamometer

3.2 Construction of Rope Brake Dynamometer

3.3 Working of Rope Brake Dynamometer

6

7

7

8

IV 4. SURVEY OR COMPARISION

4.1 Difference between Brake and Dynamometer

4.2 Difference Between Rope Brake Dynamometer And

Prony Brake Dynamometer

11

12

12

V 5. APPLICATION

5.1 Applications of Rope Brake Dynamometer

13

14

VI 6. CONCLUSION 16

VII 8. REFERENCE 18


Department of Mechanical Engineering, SVPCET 2013-2014 iii

LIST OF FIGURES

SR. NO. NAME OF FIGURE PAGE NO.

01 FIG. 1.1 Types of Dynamometer

02

02 Fig. 3.1 Rope

07

03 Fig. 3.2 Pulley

08

04 Fig. 3.3 Spring Balance

08

05 FIG. : 3.4 Rope Brake Dynamometer

09

06 FIG. : 3.5 ACTUAL VIEW OF ROPE BRAKE DYNAMOMETER 10


- Department of Mechanical Engineering, SVPCET 2013-2014 iv

LIST OF TABLE

SR. NO. NAME OF TABLE PAGE NO.

01 TABLE 3.1 Parts of Rope Brake Dynamometer

07

02 TABLE 4.1 Difference Between Brakes And Dynamometer

12

03 TABLE 4.2 Difference Between Rope Brake And Prony Brake

Dynamometer

12


Department of Mechanical Engineering, SVPCET 2013-2014 v

SYMBOLS USED

W = weight attached

S = Spring Balance

r = Effective radius = rd + r1

rd = Radius of Brake drum

r1 = Radius of rope

n = r.p.m. of the engine


Department of Mechanical Engineering, SVPCET 2013-2014 vi

ABSTRACT

An absorption dynamometer consisting of a rope encircling a brake drum or flywheel,

one end of the rope being loaded by weights and the other supported by a spring balance. The

effective torque absorbed is obtained by multiplying the drum radius by the difference of the

tensions.

A dynamometer or "dyno" for short, is a device for measuring force, moment of force

(torque), or power. For example, the power produced by an engine, motor or other rotating prime

mover can be calculated by simultaneously measuring torque and rotational speed (RPM).

A dynamometer can also be used to determine the torque and power required to operate a

driven machine such as a pump. In that case, a motoring or driving dynamometer is used. A

dynamometer that is designed to be driven is called an absorption or passive dynamometer. A

dynamometer that can either drive or absorb is called a universal or active dynamometer.

In addition to being used to determine the torque or power characteristics of a machine

under test (MUT), dynamometers are employed in a number of other roles. In standard emissions

testing cycles such as those defined by the United States Environmental Protection Agency (US

EPA), dynamometers are used to provide simulated road loading of either the engine (using an

engine dynamometer) or full powertrain (using a chassis dynamometer). In fact, beyond simple

power and torque measurements, dynamometers can be used as part of a testbed for a variety of

engine development activities, such as the calibration of engine management controllers, detailed

investigations into combustion behavior, and tribology.

In the medical terminology, hand-held dynamometers are used for routine screening of

grip and hand strength, and the initial and ongoing evaluation of patients with hand trauma or

dysfunction. They are also used to measure grip strength in patients where compromise of the

cervical nerve roots or peripheral nerves is suspected.


Department of Mechanical Engineering, SVPCET 2013-2014 1

CHAPTER 1

INTRODUCTION



CHAPTER 1

INTRODUCTION

1.1 Definition of Dynamometer:

Dynamometer a device with a rotating shaft that is coupled to the shaft of a machine under

test to measure the output torque or the required driving torque of the machine. The torque

measured by the dynamometer is multiplied by the shaft angular velocity, measured by a

tachometer, to compute the horsepower of the machine under test. Dynamometers are used to

determine the torque and horsepower characteristics of electric motors, generators, internal

combustion engines, gas turbines, and pumps.

1.2 Types of Dynamometer

1.3 Absorption Dynamometer: In this type, the work done is converted into heat by friction while being measured. They

can be used for measurement of moderate powers only.

Example: Prony Brake dynamometer and rope brake dynamometer.

FIG. 1.1 Types of Dynamometer



1.4 Transmission Dynamometer:

In this type, the work is not absorbed in the process, but is utilized after the measurement.

Example: Belt transmission dynamometer and Torsion dynamometer.

1.5 Theory of Dynamometer:

Dynamometers are used for measurement of brake power. To measure brake power, the engine

torque and angular speed have to measured. A typical dynamometer is shown.The rotor is driven

by the engine under test by mechanical, hydraulic or electromagnetic means. The rotor is coupled

to the stator. For each revolution of the shaft,

Work done = 2××R×F

Now, external torque = S×L, where S is the scale reading and L is the length of dynamometer

arm.

Therefore, S×L = R×F for balance of dynamometer.

The power is given by, Brake Power = 2×N×T / 60

In the absorption dynamometers, the entire energy or power produced by the engine is absorbed

by the friction resistances of the brake and is transformed into heat, during the process of

measurement. But in the transmission dynamometer energy is not wasted in friction but is

utilized in doing work. The energy or power produced by engine is transmitted through the

dynamometers in some other machines where the power developed is suitably measured.



CHAPTER 2

LITERATURE REVIEW



CHAPTER 2

LITERATURE REVIEW

1. Guan and Huang (2003) proposed a method to measure disc brake squeal propensity. In the

past via the complex eigen value analysis, positive real parts always indicate the level of

instability. Instead of using this generic parameter to show degrees of instability, they

attempted to analyze the squeal problem from the viewpoint of energy. The total feed-in

energy was used to indicate the squeal tendency of the brake system, which was derived

using the magnitude and phase of the modal shape coefficient vector. They concluded the

proposed method would be able to predict disc brake tendency as similar as the positive real

parts of t he complex eigen value analysis. Furthermore, the method allows disclosing the

influence of structure design parameter on the squeal propensity and also helps analyzing

the effectiveness of various modifications to reduce/eliminate squeal.

2. Moirot et al (2000) proposed an analysis to deal with the squeal problems. The analysis had

three major aspects that differ from typical complex eigen value analysis. The proposed

analysis, first performed non-linear static calculation to determine the contact surface

between the disc and the pads. The second aspect was they considered the damping that due

to friction and the final aspect was the projection of the whole structure on a real modal basis.

3. Chung et al (2001) presented an analysis approach by transferring the equations of motion

from transient domain to modal domain that the transformation could significantly reduce

the complexity of the complex eigenvalue analysis. The modal domain analysis could

provide mechanism underlying the mode-coupling phenomenon. The instability was

investigated based on the propensity of modes to couple and cause squeal. From the

analysis, even if modes were separated enough in frequency that there was no instability, it

was still possible to predict which mode might couple and create instability if the modes

were slightly shifted. Thus, it could provide the guidance needed to design squeal-free

system. The proposed analysis proved to be successful as good correlations were achieved

against experimental results.



CHAPTER 3

WORKING PRINCIPLE



CHAPTER 3

WORKING PRINCIPLE

3.1 Parts of a Rope Brake Dynamometer:

The basic parts of a rope brake dynamometer are as follows:

1. Ropes

2. Pulley

3. Dead Weight

4. Spring Balance

5. Plywood frame

SR. NO. DESCRIPTION MATERIAL QUANTITY

01 Rope Synthetic Fibers 01

02 Pulley Wood 01

03 Dead Weight Cast Iron 01

04 Spring Balance Mild Steel 01

05 Plywood Frame Plywood 01

3.2 Construction of Rope Brake Dynamometer: 1. Rope: A rope is a linear collection of natural or artificial plies, yarns or strands which are

twisted or braided together in order to combine them into a larger and stronger form, but is

not a cable or wire. Ropes have tensile strength and so can

be used for dragging and lifting, but are far too flexible to

provide compressive strength. As a result, they cannot be

used for pushing or similar compressive applications.

Rope is thicker and stronger than similarly constructed

cord, line, string, and twine. We have selected rope of

10mm Diameter.

TABLE 3.1 Parts of Rope Brake Dynamometer

Fig. 3.1 Rope



2. Pulley: A pulley is a wheel on an axle that is

designed to support movement and change of

direction of a cable or belt along its circumference.

Pulleys are used in a variety of ways to lift loads,

apply forces, and to transmit power. In nautical

contexts, the assembly of wheel, axle, and

supporting shell is referred to as a "block." Pulley

that we have chosen is 90mm in diameter.

3. Dead Weight: Its a heavy weight or load. Dead weight we have selected is of

457gm.

4. Spring Balance: A spring balance apparatus is simply

a spring fixed at one end with a hook to attach an object

at the other. It works by Hooke's Law, which states that

the force needed to extend a spring is proportional to the

distance that spring is extended from its rest position.

Therefore the scale markings on the spring balance are

equally spaced.

3.3 Working of Rope Brake Dynamometer: In a rope brake dynamometer a rope is wrapped over the rime of a pulley keyed to the

shaft of the engine. The diameter of the rope depends upon the power of the machine. The

spacing of the rope on the pulley is done by 3 to 4 U-shaped wooden blocks which also

prevent rope from slipping of the pulley. The upper end of a rope is attached to the spring

balance whereas the lower end supports the weight of suspended mass.

If the power is high, so will be the heat produced due to friction between the rope and the

wheel, and a cooling arrangement is necessary. For this, the channel of the flywheel usually

has flange turned inside in which water from a ripe is supplied. An outlet pipe with a

flattened end takes the water out.

Fig. 3.2 Pulley

Fig. 3.3 Spring Balance



A rope brake dynamometer is frequently used to test the power of the engines. It is easy

to manufacture, inexpensive, and requires no lubrication.

If the rope is wrapped several times over the wheel, the tension of the slack side of the

rope, i.e., the spring balance reading can be reduced to a negligible value as compared to the

tension of the tight side (as T1/T2 = 푒 푎푛푑휃is increased). Thus one can even do away

with the spring balance.

Let,

W = weight attached

S = Spring Balance

r = Effective radius = rd + r1

Where,

rd = Radius of Brake drum

r1 = Radius of rope

n = r.p.m. of the engine

Therefore, Braking Torque, Tb = (W-s) * r

The power absorbed by the engine = ( )∗

(KW)

ENGINE SHAFT

SPRING BALNCE

WOODEN BLOCKS

FIG. : 3.4 ROPE BRAKE DYNAMOMETER



FIG. : 3.5 ACTUAL VIEW OF ROPE BRAKE DYNAMOMETER



CHAPTER 4

SURVEY OR COMPARISION



CHAPTER 4

SURVEY OR COMPARISION

4.1 Difference between Brake and Dynamometer

Sr. No. Brakes Dynamometer

1 Principle object is to absorb

energy. Works on principle of absorption.

2 It is used to retard or stop. It is able to measure absorb K.E.

transmitted to prime mover.

3 No torque or power is measured It measures, torque and hence

power.

4.2 Difference Between Rope Brake Dynamometer And Prony Brake Dynamometer:

Sr. No. Rope Brake Dynamometer Prony Brake Dynamometer

01 Cooling arrangement is required, since

friction is developed

No cooling arrangement is required.

02 Its accuracy is comparatively more. Its accuracy is comparatively less.

03 Its Construction is Simple. Its construction is complex.

04 It is comparatively cheaper. It is comparatively expensive.

05 It consists of less no. of parts. It consists of more no. of parts.

06 푃표푤푒푟 = ( )∗ /60 푃표푤푒푟 =

∗ ∗ ∗ /60

TABLE 4.1 DIFFERNCE BETWEEN BRAKES AND DYNAMOMETER

TABLE 4.2 DIFFERENCE BETWEEN ROPE BRAKE AND PRONY BRAKE DYNAMOMETER



CHAPTER 5

APPLICATION



CHAPTER 5

APPLICATION

5.1 Applications of Rope Brake Dynamometer: 1. The main application of a rope brake dynamometer is to test IC Engine.

Dynamometers are useful in the development and refinement of modern engine

technology. The concept is to use a dyno to measure and compare power transfer at

different points on a vehicle, thus allowing the engine or drivetrain to be modified to get

more efficient power transfer. For example, if an engine dyno shows that a particular

engine achieves 400 N·m (295 lbf·ft) of torque, and a chassis dynamo shows only

350 N·m (258 lbf·ft), one would know to look to the drive train for the major

improvements. Dynamometers are typically very expensive pieces of equipment, and so

are normally only used in certain fields that rely on them for a particular purpose.

2. It is also used in Pelton Wheel Turbine to measure the torque, then power.

The turbine whose torque is to be measured, its shaft is connected to the shaft of rape

brake dynamometer on which drum or pulley is mounted. Rope is wrapped on the

periphery of drum. Tension is provided from the both ends by attaching one end of rope

with spring balance and other with dead weight. This restricts the motion pulley which

gives reading in spring balance. Ultimately torque can be calculated.

3. It is used for measuring the torque in Francis Turbine.

4. It can be used for measuring torque of any rotary member, simply by

coupling it with shaft of dynamometer.



CHAPTER 6

CONCLUSION



CHAPTER 6

CONCLUSION

A brake is an appliance used to apply frictional resistance to a moving body to stop or

retard it by absorbing its kinetic energy. In general, in all types of motion, there is always some

amount of resistance which retards the motion and is sufficient to bring the body to rest.

However, the time taken and the distance covered in this process is usually too large. By

providing brakes, the external resistance is considerably increased and the period retardation

shortened.

A dynamometer is a brake incorporating a device to measure the frictional resistance

applied. This is used to determine the power developed by the machine, while maintaining its

speed at the rated value.

The functional difference between a clutch and a brake is that a clutch connects two

moving members of a machine whereas a brake connects a moving member to a stationary

member.

The determination of power delivered to rotating machinery simultaneous measurement

of torque and shaft speed. Machines used for torque measurement under test – bed condition are

called dynamometer. The type of dynamometer to be used depends on the nature of machine to

be tested.

Absorption dynamometers working principle is that the power measured is converted into

heat by friction or by other means. The power absorbed is lost as heat and is dissipated to the

surrounding where it have no use.

These are used for measurement of power of generator, electric motor, turbines and

engines. Dynamometers are capable only of power absorption include various forms of

mechanical brakes working on dry friction, fluid friction and eddy current brake.



CHAPTER 7

REFERENCES



CHAPTER 7

REFERENCES

1. Prabhu, T.J., Fundamentals of Machine Design.

2. Khurmi, R.S. and J.K. Gupta, Theory of Machines.

3. Sundararajamoorthy, T.V. and N. Shanmugam, Machine Design.

4. Thipse, S.S., Internal Combustion Engines.

5. Mathur, M.L. and R.P. Sharma, Internal Combustion

6. SS Rattan, Theory of machines (TATA McGraw Hill Publication).

7. V. Ganeshan, Internal Combustion Engine (TATA McGraw Hill Publication).

8. Winther, J. B. (1975). Dynamometer Handbook of Basic Theory and Applications.

Cleveland, Ohio: Eaton Corporation.

9. Martyr, A.; Plint, M. (2007). Engine Testing - Theory and Practice (Fourth ed.). Oxford.

10. www.rugusavay.com

11. www.dynamometers.org

12. www.dyno-dynamometer.com

13. www.idosi.org

Education

Rope brake dynamometer