EnhancinThe Role of Electromagnetic Brakes in Automotive Engineering

Introduction

Electromagnetic brakes are the brakes working on the electric power &magnetic power. They works on the principle of electromagnetism. These are totally friction less. Due to this they are more durable & have longer life span. Less maintenance is there. These brakes are an excellent replacement on the convectional brakes due to their many advantages. The reason for implementing this brake in automobiles is to reduce wear in brakes as it friction less. Therefore there will also be no heat loss. It can be used in heavy vehicles as well as in light vehicles.

The electromagnetic brakes are much effective than conventional brakes & the time taken for application of brakes are also smaller. There is very few need of lubrication. Electromagnetic brakes gives such better performance with less cost which is today’s need. There are also many more advantages of Electromagnetic brakes. That’s why electromagnetic brakes are an excellent replacement on conventional brakes.

Electromagnetic brakes are of today’s automobiles. An electromagnetic braking system for automobiles like cars, an effective braking system. And, by using this electromagnetic brakes, we can increase the life of the braking unit. The working principle of this system is that when the magnetic flux passes through and perpendicular to the rotating wheel the eddy current flows opposite to the rotating wheel/rotor direction. This eddy current trying to stop the rotating wheel or rotor. This results in the rotating wheel or rotor comes to rest/ neutral.

HISTORY of the electromagnetic brake

Electromagnetic brakes can generate nearly twice the maximum power output of a typical engine and triple the braking power of an exhaust brake (Reverdin, 1994). As supplementary retarders, they reduce friction brake use, preventing overheating. This extends brake lining life significantly and eliminates brake fade risk, making electromagnetic brakes a highly competitive alternative to other retarder systems.

Research by a truck manufacturer showed electromagnetic brakes handled 80% of braking duty typically done by service brakes (Reverdin, 1974). They also reduce risks from prolonged brake use beyond heat dissipation capacity.

This scenario often occurs when a 40-ton, five-axle vehicle with a 310 bhp engine descends a 6% slope at 35–40 mph. Maintaining speed requires about 450 hp of braking force, with the system dissipating 300 hp. With five axles, each brake must absorb roughly 30 hp—an energy level that would usually destroy a standard friction brake.

The magnetic brake suits such conditions, independently absorbing over 300 hp (Reverdin, 1974). It meets continuous braking needs, keeping friction brakes cool and ready for emergency use, ensuring total safety.

The installation of an electromagnetic brake is not very difficulty if there is enough space between the gearbox and the rear axle. If did not need a subsidiary cooling system. It relay on the efficiency of engine components for its use, so do exhaust and hydrokinetic brakes. The exhaust brake is an on/off device and hydrokinetic brakes have very complex control system. The electromagnetic brake control system is an electric switching system which gives it superior controllability.

Construction of Electromagnetic Brake

 

The electromagnetic braking system is straightforward, comprising an electromagnet, rheostat, sensors, and a magnetic insulator. A cylindrical, ring-shaped electromagnet with windings is fixed like a stator and positioned parallel to the rotating wheel disc or rotor, with coils wound along its circumference.

The coils connect to an electrical circuit with a rheostat linked to the brake pedal, controlling current and magnetic flux. It also prevents magnetization of parts like the axle and supports the electromagnet. A sensor detects circuit disconnections, alerting users to errors and helping prevent accidents.

Let's explore each of these components in detail:

1.Electromagnet

• The essential part of the electromagnetic brake is an electromagnet. A magnetic field is formed as a result of the ferrous core used along with winding coil having electric current flow through it.
• The intensity of the magnetic field is defined by aspects such as number of wire turns, applied current and core material properties.

2.Armature

• Being a vital component of the brake, the armature is connected to its moving part. It is usually a conductor that interacts with the magnetic field created by an electromagnet.
• Once the brake is applied, an electromagnet attracts the armature and provides a mechanical connection between them.

3.Friction Surface

• A friction surface is used to transform the magnetic force into a braking action. This surface is usually a disc or a ‘high friction’ drum.
• With the armature pulling towards the electromagnet it bears against a friction surface, which generates the much needed kinetic energy that slows down or stops moving equipment.

4.Spring

• In case of removal of electromagnetic force, a spring is incorporated in the brake system to guarantee disengagement. This spring is created such that it causes the armature to move away from the electromagnet when there is no current.

Working principle of the electromagnetic brake

The working principle of the electric retarder is based on the electric retarder is based on the creation of eddy currents within a metal discs rotating between two electro magnets, which set up a force opposing the rotation of the discs. If the electromagnet is not energized, the rotation of the disc 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 slowed due to the braking force generated by eddy currents. The kinetic energy absorbed during this process is converted into heat, raising the temperature of the discs. If the current exciting the electromagnet is varied using a rheostat, the braking force varies in direct proportion to the current.

The development of this invention began with the French company Telma, in association with Raoul Sarasin, which developed and marketed several generations of electric brakes based on the operating principle described above.

A typical electric retarder consists of a stator and a rotor. The stator houses 16 induction coils, which are energized in groups of four. These coils are made of varnished aluminum wire and are embedded in epoxy resin for insulation and durability.

1. The installation of an electromagnetic brake is very difficult if there is Not enough space between the gearbox and the rear axle.
2. Need a separate compressor.
3. Maintenance of the equipment components such as hoses, valves has to done periodically.
4. It cannot use grease or oil.

Applications of electromagnetic brake

1. Used in crane control system.
2. Used in winch controlling.
3. Used in lift controlling.
4. Used in automatic purpose.

The lots of new technologies are arriving in world. They create a lot of effect. Most industries got their new faces due to this arrival of technologies. Automobile industry is also one of them.

There is a boom in World’s automobile industry. So lots of research is also going here. As an important part of automobile, there are also innovations in brakes. Electromagnetic brake is one of them.

A electromagnetic braking for automobiles like cars, an effective braking system. And, by using this electromagnetic brakes, we can increase the life of the braking unit. The working principle of this system is based on electromagnetic flux passing perpendicularly through the rotating wheel, which induces eddy currents in the rotor. This eddy current flows opposite to the rotating wheel. This eddy current tries to stop the rotating wheel or rotor. This results in the rotating wheel or rotor comes to rest.

Conclusion

The electromagnetic brake stands as a testomony to the innovation and synergy between electric and mechanical engineering. Its capacity to provide unique and responsive braking has made it an critical element in numerous technological landscapes. As industries keep to conform, the electromagnetic brake will probable play an increasingly more pivotal role in shaping the efficiency and safety of various packages. It represents no longer simplest a technological advancement however additionally a testomony to the countless possibilities when technological know-how and engineering converge.