fyp electromagnetic-brakes
TRANSCRIPT
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A
PROJECT REPORT ON
“ELECTROMAGNETIC BRAKE”
Submitted in partial fulfillment of the award
BACHELOR OF TECHNOLOGY
In
(Mechanical Engineering)
Session 2012-13
Submitted By:
AJAY YADAV (0935740003)
Under the Guidance
Of
Mr. SANDEEP SINGH
(Lecturer, M.E Department)
Aryavart Institute Of Technology & Management , Lucknow
Affilated To
Gautam Budha Technical University, Lucknow
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CERTIFICATE
This is to certify that Project synopsis entitled “ELECTROMAGNETIC BRAKE” which is submitted by AJAY YADAV in partial fulfillment of requirement for the award of degree Bachelor Of Technology in MECHANICAL ENGINEERING from ARYAVART INSTITUTE OF TECHNOLOGY & MANAGEMENT , LUCKNOW (G.B.T.U) is a record of the candidate own work carried out by her under my supervision . The matter embodied in this project is original and has not been submitted
for the award of any other degree.
Under the Guidance of: Submitted To:
Mr. SANDEEP SINGH Mr. PRINCE SRIVASTAVA (Lecturer, ME Department) H.O.D (ME Department)
Mr. SIMANT SRIVASTAVA
(DEAN)
(ME Department)
Date :
Place:
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ACKNOWLEDGEMENT
One of the parts of preparing this project is to thanks those who have helped me through their valuable participation , comments and suggestion . We wish to thank’s , ARYAVART INSTITUTE OF TECHNOLOGY & MANAGEMENT , LUCKNOW whose co-operation and attitude toward encouraging a student is appreciable . We sincerely express our gratitude to the project guide Mr. Sandeep Singh (Lecturer, ME Department) for his guidance in completing the project titled ‘electromagnetic brake’ . Without his guidance this project would not have been completed , her kindness and help have been the source of encouragement for us thoughout the project.
We would like to thanks our project coordinator Mr. prince srivastava for all his support and help in collecting information about ‘ELECTROMAGNETIC BRAKE’ , implementing the same in the project and using it successfully. Last but not the least , we express our deep gratitude to our academic dean Mr. Simant Srivastava for contribution of his ideas for our project . We would also like to pay our regard to the whole M.E department for their support and guidance .
Finally a lot of thanks to our friends and family member , who helped and motivation us to develop such a wonderful solution.
(AJAY YADAV)
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TABLE OF CONTENTS
• INTRODUCTION
• GENERAL PRINCIPLE OF BRAKE SYSTEM
• Conventional Friction Brake
• How ordinary (friction) brakes work
• “Brake Fading” Effect
• Retarders
• Construction
• General Principle and Advantage of Electromagnetic Brakes (retarders)
• Working Principle
• Electric Control System
• TYPES OF ELECTROMAGNETIC BRAKE
• Characteristic of Electromagnetic Brakes
• Thermal Dynamics
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• MERITS
• DERMIRTS
• APPLICATION
• Summary
1. Introduction
Electromagnetic brakes have been used as supplementary retardation
equipment in addition to the regular friction brakes on heavy vehicles. We
outline the general principles of regular brakes and several alternative
retardation techniques in this section. The working principle and characteristics
of electromagnetic brakes are then highlighted. In this project we are trying to
make a braking system. which can be applicable in two wheeler at high speed
and low maintenance cost. Here we are using an electromagnetic coil and a
plunger. There is an electromagnetic effect which moves the plunger in the
braking direction.
When electricity is applied to the field, it creates an
internal magnetic flux. That flux is then transferred into a hysteresis disk
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passing through the field. The hysteresis disk is attached to the brake shaft. A
magnetic drag on the hysteresis disk allows for a constant drag, or eventual
stoppage of the output shaft.
Electromagnetic brakes (also called electro-mechanical
brakes or EM brakes) slow or stop motion using electromagnetic force to apply
mechanical resistance (friction). The original name was "electro-mechanical
brakes" but over the years the name changed to "electromagnetic brakes",
referring to their actuation method. Since becoming popular in the mid-20th
century especially in trains and trolleys, the variety of applications and brake
designs has increased dramatically, but the basic operation remains the same.
Both electromagnetic brakes and eddy current brakes use electromagnetic force
but electromagnetic brakes ultimately depend on friction and eddy current
brakes use magnetic force directly.
Materials
36 Gauge Magnet wire ,
AC Motor ,
Sprint ,
Iron Stand,
Wheel
Description:
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The disc brake or disk brake is a device for slowing or stopping the rotation of a
wheel. A brake disc usually made of cast iron or ceramic composites is
connected to the wheel and the axle. To stop the wheel, friction material in the
form of brake pads is forced mechanically, hydraulically, pneumatically or
electromagnetically against both sides of the disc. Friction causes the disc and
attached wheel to slow or stop. But in our project hydraulic energy is used as
the source of power, due to high applied force and torque
2. General Principle of Brake System
The principle of braking in road vehicles involves the conversion of kinetic
energy into thermal energy (heat). When stepping on the brakes, the driver
commands a stopping force several times as powerful as the force that puts the
car in motion and dissipates the associated kinetic energy as heat. Brakes must
be able to arrest the speed of a vehicle in a short periods of time regardless
how fast the speed is. As a result, the brakes are required to have the ability to
generating high torque and absorbing energy at extremely high rates for short
periods of time. Brakes may be applied for a prolonged periods of time in some
applications such as a heavy vehicle descending a long gradient at high speed.
Brakes have to have the mechanism to keep the heat absorption capability for
prolonged periods of time.
3. Conventional Friction Brake
The conventional friction brake system is composed of the following basic
components: the “master cylinder” which is located under the hood is directly
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connected to the brake pedal, and converts the drivers’ foot pressure into
hydraulic pressure. Steel “brake hoses” connect the master cylinder to the
“slave cylinders” located at each wheel. Brake fluid, specially designed to work
in extreme temperature conditions, fills the system. “Shoes” or “pads” are
pushed by the slave cylinders to contact the “drums” or “rotors,” thus causing
drag, which slows the car. Two major kinds of friction brakes are disc brakes
and drum brakes. Disc brakes use a clamping action to produce friction between
the “rotor” and the “pads” mount in the “caliper” attached to the suspension
members Disc brakes work using the same basic principle as the brakes on a
bicycle: as the caliper pinches the wheel with pads on both sides, it slows the
vehicle.
Drum brakes consist of a heavy flat-topped cylinder, which is
sandwiched between the wheel rim and the wheel hub . The inside surface of
the drum is acted upon by the linings of the brake shoes. When the brakes are
applied, the brake shoes are forced into contact with the inside surface of the
brake drum to slow the rotation of the wheels.
Air brakes use standard hydraulic brake system components such as
braking lines, wheel cylinders and a slave cylinder similar to a master cylinder
to transmit the air-pressure-produced braking energy to the wheel brakes. Air
brakes are used frequently when greater braking capacity is required.
4-How ordinary (friction) brakes work
Moving things have kinetic energy and, if you want to stop them, you have to
get rid of that energy somehow. If you're on a bicycle going fairly slowly, you
can simply put your feet down so they drag on the ground. The soles of your
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feet act as brakes. Friction (rubbing) between the rough ground and the grip on
your soles slows you down, converting your kinetic energy into heat energy (do
it long enough and your shoes will get hot). Brakes on vehicles work pretty
much the same way, with "shoes" that press rubber pads (brake blocks) against
discs mounted to the wheels. (Find out more about this in our main article on
brakes.) Even if you make brakes from super-strong, hard-wearing materials
like Kevlar®, they're still going to wear out sooner or later. But there are other
problems with friction brakes. The faster you go, the harder they have to work
to get rid of your kinetic energy, and the quicker they'll wear out. Use your
brakes too often and you may suffer a problem called brake fade, where heat
builds up too much in the brakes or the hydraulic system that operates them
and the brakes can no longer work as effectively. What if your brakes can't stop
you in time?
In Motorcycle brakes , When you pull on the brake handle, a
hydraulic cable applies the brake pads to the brake rotor disc, slowing the
machine down by converting your kinetic energy to heat. The tire doesn't
normally play much part in braking unless you brake really hard: then the wheel
will lock completely and friction between the tire and the road will bring you to a
sudden halt, leaving a rubber skid mark on the road. That's not a good way to
brake: it'll wear out your tires very quickly.
5. “Brake Fading” Effect
The conventional friction brake can absorb and convert enormous energy values
(25h.p. without self-destruction for an 5-axle truck, Reverdin1974), but only if
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the temperature rise of the friction contact materials is controlled. This high
energy conversion therefore demands an appropriate rate of heat dissipation if
a reasonable temperature and performance stability are to be maintained.
Unfortunately, design, construction, and location features all severely limit the
heat dissipation function of the friction brake to short and intermittent periods
of application. This could lead to a ‘brake fade’ problem (reduction of the
coefficient of friction, less friction force generated) due to the high temperature
caused by heavy brake demands. The main reasons why conventional friction
brakes fail to dissipate heat rapidly are as follows:
- poor ventilation due to encapsulation in the road wheels,
- diameter restriction due to tire dimensions,
- width restrictions imposed by the vehicle spring designer;
- problems of drum distortion at widely varying temperatures.
It is common for friction-brake drums to exceed 500 °C surface temperatures
when subject to heavy braking demands, and at temperatures of this order, a
reduction in the coefficient of friction (‘brake fade’) suddenly occurs. The
potential hazard of tire deterioration and bursts is perhaps also serious due to
the close proximity of overheated brake drums to the inner diameter of the tire.
5. Retarders
Retarders are means of of overcoming the above problems by augmenting a
vehicle’s foundation brakes with a device capable of opposing vehicle motion at
relatively low levels of power dissipation for long periods. There are several
retarder technologies currently available. Two major kinds are the hydrokinetic
brake and the exhaust brake. Hydrokinetic brake uses fluid as the working
medium to oppose rotary motion and absorb energy . Hydrodynamic brakes are
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often built into hydrodynamic transmissions . Exhaust brakes use a valve which
is fitted into the exhaust pipe between the exhaust manifold and silencer. When
this valve is closed air is compressed against it through the open exhaust valve
by the piston rising on the exhaust stroke. In that way the engine becomes a
low pressure single stage compressor driven by the vehicle’s momentum,
resulting in a retarding effect being transmitted through the transmission to the
driving road wheels. The power-producing engine is converted into a power
absorbing air compressor . This approach could put a lot of stress on the
cylinder and exhaust system. So it may require extra engineering efforts to
implement this system. As a brake applied to the engine, exhaust brakes can
only absorb as much power as the engine can deliver. But the power absorbed
in braking is usually greater than the power absorbed in driving. Compared with
these retarders, electromagnetic brakes have greater power capability,
simplicity of installation and controllability.
6-construction-
The construction of the electromagnetic braking system is very simple. The
parts needed for the construction are electro magnets, rheostat, sensors and
magnetic insulator. A cylindrical ring shaped electro magnet with winding is
placed parallel to rotating wheel disc/ rotor. The electro magnet is fixed, like as
stator and coils are wounded along the electromagnet. These coils are
connected with electrical circuit containing one rheostat which is connected
with brake pedal. And the rheostat is used to control the electric current flowing
in the coils which are wounded on the electro magnet and a magnetic insulator
is used to focus and control the magnetic flux. And also it is used to prevent the
magnetisation of other parts like axle and it act as a support frame for the
electromagnet. The sensors used to indicate the disconnection in the whole
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circuit. If there is any error it gives an alert, so we can avoid accident. Working
principle : At the initial stage the brake pedal and rheostat are in rest. When we
apply the brake through the brake pedal, the rheostat allows the current to flow
through the circuit and this current energise the electromagnet. The amount of
current flow is controlled by the rheostat. Depending on the current flow
different amount of magnetic flux can be obtained. By this varying magnetic
flux, different mode of brakes can be obtained. For example, if we want to
suddenly stop the vehicle then press the brake pedal fully, then the rheostat
allos maximum current which is enough to stop the vehicle. Similarly we can
reduce the speed of the vehicle by applying the brake gradually.
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7. General Principle and Advantage of Electromagnetic Brakes
(retarders)
Installation Location
Electromagnetic brakes work in a relatively cool condition and satisfy all the
energy requirements of braking at high speeds, completely without the use of
friction. Due to its specific installation location (transmission line of rigid
vehicles), electro magnetic brakes have better heat dissipation capability to
avoid problems that friction brakes face as we mentioned before. Typically,
electromagnetic brakes have been mounted in the transmission line of vehicles,
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The propeller shaft is divided and fitted with a sliding universal joint and is
connected to the coupling flange on the brake. The brake is fitted into the
chassis of the vehicle by means of anti-vibration mounting. The practical
location of the retarder within the vehicle prevents the direct impingement of air
on the retarder caused by the motion of the vehicle. Any air flow movement
within the chassis of the vehicle is found to have a relatively insignificant effect
on the air flow around tire areas and hence on the temperature of both front
and rear discs. So the application of the retarder does not affect the
temperature of the regular brakes. In that way, the retarders help to extend the
life span of the regular brakes and keep the regular brakes cool for emergency
situation. Electromagnetic brakes work in a relatively cool condition and satisfy
all
the energy requirements of braking at high speeds, completely without the use
of friction. Due to its specific installation location (transmission line of rigid
vehicles).
There are in existence several types of electromagnetic retarder. In
particular, there are electromagnetic retarders of the axial type and
electromagnetic retarders of the Focal type. An electromagnetic retarder of the
axial type is designed to be placed on a transmission shaft between a rear
axle and a gearbox of the vehicle. In that case, the transmission shaft is in two
parts, for mounting between those of the retarder. An electromagnetic retarder
of the Focal type is designed to be placed directly on a transmission shaft on the
output side of the gearbox or on the axle of the vehicle. The axle of a vehicle
drives at least one road wheel, which road wheel drives at least one wheel of
the same vehicle.
8. Working Principle-
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The working principle of the electric retarder is based on the creation of eddy
currents within a metal disc rotating between two electromagnets, which sets
up a force opposing the rotation of the disc . If the electromagnet is not
energized, the rotation of the disc is free and accelerates uniformly under the
action of the weight to which its shaft is connected. When the electromagnet is
energized, the rotation of the disc is retarded and the energy absorbed appears
as heating of the disc. If the current exciting the electromagnet is varied by a
rheostat, the braking torque varies in direct proportion to the value of the
current. It was the Frenchman Raoul Sarazin who made the first vehicle
application of eddy current brakes. The development of this invention began
when the French company Telma, associated with Raoul
Sarazin, developed and marketed several generations of electric brakes based
on the functioning principles described above . A typical retarder consists of
stator and rotor. The stator holds 16 induction coils, energized separately in
groups of four. The coils are made up of varnished aluminum wire mounded in
epoxy resin. . The rotor is made up of two discs, which provide the braking
force. when subject to the electromagnetic influence when the coils are excited.
Careful design of the fins, which are integral to the disc, permit independent
cooling of the arrangement.
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9. Electric Control System
The energization of the retarder is operated by a hand control mounted on the
steering column of the vehicle. This control has five positions: the first is ‘off’,
and the four remaining positions increase the braking power in sequence. This
hand-control system can be replaced by an automatic type that can operate
mechanically through the brake pedal. In this case, the contacts are switched
on successively over the slack movement of the brake pedal. The use of an
automatic control must be coupled with a cut-off system operating at very low
vehicle speed in order to prevent energization of the retarder while the vehicle
is stationary with the driver maintaining pressure on the brake pedal. Both the
manual control and the automatic control activate four solenoid contractors in
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the relay box, which in turn close the four groups of coil circuits within the
electric brake at either 24 volts or 12 volts, as appropriate (Reverdin 1974 and
Omega Technologies).
10-TYPES OF ELECTROMAGNETIC BRAKE
(1)-Single Disc Electromagnetic Brakes-
Features:-
• Brake is used to Brake and maintain the rotating body
• Designed for dry-operation
• Slim Brakes with good performance and can quickly stop loads
• Lightweight and easy to mount in any machinery
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• We manufacture Single Disc Electromagnetic Brakes - Equivalents to
world leading manufacturers like:Intorq, Lenze, KEB, PSP, Miki-Pulley and
more
Technical Features:
• These can quickly stop loads
• Technical Features Torque: 3NM to 500NM
• Single Plate Dry Type
• High Operating Reliability / frequency
• Simple Construction
• Unique pre-stressed spring
• Raw material to DIN standards
• Special friction material
• Can be used in mounting positions
• Different armature designs are available for different applications
• Different voltages options are also available on request.
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(2)-Multi-Disc Electromagnetic Brakes -Brake with magnet body front face
fastened to housing For oil operation.
Equivalents to ZF Brakes - EK 1B, EK 2DB, EK 5DB, EK 10EB, EK 20DB, EK
20EB, EK 40DB, EK 40EB, EK 60DB, EK 80B, EK 120EB, EK 160B, EK 320B.
Technical Features:
• Coil Voltage: 24 V
• Torque: 3 N-m to 3600 N-m
• Compact design
• Electromagnetic brakes are provided
• With or without outer carrier, jaw and driver
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• With inner & outer multiple discs.
(3)Single face brake
Main article: Friction-plate electromagnetic couplings
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A friction-plate brake uses a single plate friction surface to engage the input
and output members of the clutch. Single face electromagnetic brakes make
up approximately 80% of all of the power applied brake applications.
(4)Power off brake
Electormagnetic Power Off Brake Spring Set
Power off brakes stop or hold a load when electrical power is either
accidentally lost or intentionally disconnected. In the past, some companies
have referred to these as "fail safe" brakes. These brakes are typically used
on or near an electric motor. Typical applications include robotics, holding
brakes for Z axis ball screws and servo motor brakes. Brakes are available
in multiple voltages and can have either standard backlash or zero backlash
hubs. Multiple disks can also be used to increase brake torque, without
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increasing brake diameter. There are 2 main types of holding brakes. The
first is spring applied brakes. The second is permanent magnet brakes.
(a) Spring type - When no electricity is applied to the brake, a spring
pushes against a pressure plate, squeezing the friction disk between the
inner pressure plate and the outer cover plate. This frictional clamping force
is transferred to the hub, which is mounted to a shaft.
(b)Permanent magnet type – A permanent magnet holding brake looks
very similar to a standard power applied electromagnetic brake. Instead of
squeezing a friction disk, via springs, it uses permanent magnets to attract a
single face armature. When the brake is engaged, the permanent magnets
create magnetic lines of flux, which can turn attract the armature to the
brake housing. To disengage the brake, power is applied to the coil which
sets up an alternate magnetic field that cancels out the magnetic flux of the
permanent magnets.
Both power off brakes are considered to be engaged when no power is
applied to them. They are typically required to hold or to stop alone in the
event of a loss of power or when power is not available in a machine
circuit. Permanent magnet brakes have a very high torque for their size, but
also require a constant current control to offset the permanent magnetic
field. Spring applied brakes do not require a constant current control, they
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can use a simple rectifier, but are larger in diameter or would need stacked
friction disks to increase the torque.
(5)Particle brake
Magnetic Particle Brake
Magnetic particle brakes are unique in their design from other electro-
mechanical brakes because of the wide operating torque range available.
Like an electro-mechanical brake, torque to voltage is almost linear;
however, in a magnetic particle brake, torque can be controlled very
accurately (within the operating RPM range of the unit). This makes these
units ideally suited for tension control applications, such as wire winding,
foil, film, and tape tension control. Because of their fast response, they can
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also be used in high cycle applications, such as magnetic card readers,
sorting machines and labeling equipment.
Magnetic particles (very similar to iron filings) are located in the powder
cavity. When electricity is applied to the coil, the resulting magnetic flux
tries to bind the particles together, almost like a magnetic particle slush. As
the electric current is increased, the binding of the particles becomes
stronger. The brake rotor passes through these bound particles. The output
of the housing is rigidly attached to some portion of the machine. As the
particles start to bind together, a resistant force is created on the rotor,
slowing, and eventually stopping the output shaft.
When electricity is removed from the brake, the input is free to turn with
the shaft. Since magnetic particle powder is in the cavity, all magnetic
particle units have some type of minimum drag associated with them.
(6)Hysteresis power brake
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Electomagnetic Hysteresis Power Brake
Electrical hysteresis units have an extremely wide torque range. Since these
units can be controlled remotely, they are ideal for test stand applications
where varying torque is required. Since drag torque is minimal, these units
offer the widest available torque range of any of the hysteresis products.
Most applications involving powered hysteresis units are in test stand
requirements.
When electricity is applied to the field, it creates an internal magnetic flux.
That flux is then transferred into a hysteresis disk passing through the field.
The hysteresis disk is attached to the brake shaft. A magnetic drag on the
hysteresis disk allows for a constant drag, or eventual stoppage of the
output shaft.
When electricity is removed from the brake, the hysteresis disk is free to
turn, and no relative force is transmitted between either member. Therefore,
the only torque seen between the input and the output is bearing drag.
(7)Multiple disk brake
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Electromagnetic Multiple Disk Brake
Multiple disk brakes are used to deliver extremely high torque within a
small space. These brakes can be used either wet or dry, which makes them
ideal to run in multi-speed gear box applications, machine tool applications,
or in off road equipment.
Electro-mechanical disk brakes operate via electrical actuation, but transmit
torque mechanically. When electricity is applied to the coil of an
electromagnet, the magnetic flux attracts the armature to the face of the
brake. As it does so, it squeezes the inner and outer friction disks together.
The hub is normally mounted on the shaft that is rotating. The brake
housing is mounted solidly to the machine frame. As the disks are
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squeezed, torque is transmitted from the hub into the machine frame,
stopping and holding the shaft.
When electricity is removed from the brake, the armature is free to turn
with the shaft. Springs keep the friction disk and armature away from each
other. There is no contact between braking surfaces and minimal drag.
11-Characteristic of Electromagnetic Brakes-
It was found that electromagnetic brakes can develop a negative power
which represents nearly twice the maximum power output of a typical engine,
and at least three times the braking power of an exhaust brake . These
performance of electromagnetic brakes make them much more competitive
candidate for alternative retardation equipments compared with other retarders.
By using the electro-magnetic brake as supplementary10 retardation
equipment, the friction brakes can be used less frequently, and therefore
practically never reach high temperatures. The brake linings would last
considerably longer before requiring maintenance, and the potentially “brake
fade” problem could be avoided. In research conducted by a truck
manufacturer, it was proved that the electromagnetic brake assumed 80
percent of the duty which would otherwise have been demanded of the regular
service brake . Furthermore, the electromagnetic brake prevents the dangers
that can arise from the prolonged use of brakes beyond their capability to
dissipate heat. This is most likely to occur while a vehicle descending a long
gradient at high speed. In a study with a vehicle with 5 axles and weighing 40
tons powered by an engine of 310 b.h.p traveling down a gradient of 6 percent
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at a steady speed between 35 and 40 m.p.h, it can be calculated that the
braking power necessary to maintain this speed is the order of 450 h.p. The
braking effect of the engine even with a fitted exhaust brake is approximately
150 h.p. The brakes, therefore, would have to absorb 300 h.p,
meaning that each brake in the 5 axles must absorb 30 h.p, which is beyond the
limit of 25 h.p. that a friction brake can normally absorb without self
destruction. The electromagnetic brake is well suited to such conditions since it
will independently absorb more than 300 h.p . It therefore can exceed the
requirements of continuous uninterrupted braking, leaving the friction brakes
cool and ready for emergency braking in total safety. The installation of an
electromagnetic brake is not very difficult if there is enough space between the
gearbox and the rear axle. It does not need a subsidiary cooling system. It does
not rely on the efficiency of engine components for its use, as do exhaust and
hydrokinetic brakes. The electromagnetic brake also has better controllability.
The exhaust brake is an on/off device and hydrokinetic brakes have very
complex control system. The electro- magnetic brake control system is an
electric switching system which gives it superior controllability. 11 From the
foregoing, it is apparent that the electro-magnetic brake is an attractive
complement to the safe braking of heavy vehicles.
12-Thermal Dynamics-
Thermal stability of the electromagnetic brakes is achieved by means of the
convection and radiation of the heat energy at high temperature. The major
part of the heat energy is imparted to the ventilationg air which is circulating
vigorously through the fan of the heated disc. The value of the energy
dissipated by the fan can be calculated by the following expression:
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Q MCp = ∆θ (2.1)
where:
M = Mass of air circulated;
Cp = Calorific value of air;
∆θ= Difference in temperature between the air entering and the air leaving the
fan;
The electromagnetic brakes has excellent heat dissipation efficiency owing to
the high temperature of the surface of the disc which is being cooled and also
because the flow of air through the centrifugal fan is very rapid. Therefore, the
curie temperature of the disc material could never been reached .The practical
location of the electromagnetic brakes prevents the direct impingement of air on
the brakes caused by the motion of the vehicle. Any air flow movement within
the chassis of the vehicle is found to have a relatively 12 insignificant effect on
the air flow and hence temperature of both front and rear discs. Due to its
special mounting location and heat dissipation mechanism, electromagnetic
brakes have better thermal dynamic performance than regular friction brakes.
13-MERITS-
Quick operation
Accuracy is more.
It reduces the manual effort.
In electromagnetic braking system maintenance is very less.
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electromagnetic braking system work is done very fast, because of
electronic component. And flowing of current is very fast.
Very less effort is required to apply the brake.‡
It is reasonable as compare with other brakes.
14-DERMIRTS-
Cylinder stroke length is constant
Need a separate compressor
Maintenance of the equipment components such as hoses, valves
has to done periodically.
15-APPLICATION -
Used in crane control system
Used in winch controlling
Used in lift controlling Used in automobile purpose
In locomotives, a mechanical linkage transmits torque to an
electromagnetic braking component.
Trams and trains use electromagnetic track brakes where the braking
element is pressed by magnetic force to the rail. They are distinguished
from mechanical track brakes, where the braking element is mechanically
pressed on the rail.
Electric motors in industrial and robotic applications also employ
electromagnetic brakes.
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16- Summary
With all the advantages of electromagnetic brakes over friction brakes, they
have been widely used on heavy vehicles where the ‘brake fading’ problem is
serious. The same concept is being developed for application on lighter
vehicles.