06-12-2012, 06:25 PM
ELECTRO - MAGNETIC BRAKES
MAGNETIC BRAKING..docx (Size: 13.67 KB / Downloads: 104)
INTRODUCTION
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 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.
GENERAL PRINCIPLES
1.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).
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
WORKING:-
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.
In this type of electromagnetic braking system, electromagnet is fixed in the back plate in this way the unequal braking effect at one shoe are balanced, even if the lining on one shoe is worn more than other the plunger will move to one side so that shoe still share equal acting force. In this braking system, any one shoe out of two will remove & instead of it we will use the electromagnetic coil. As the current passes through this electromagnetic coil, it will produce the magnetic flux, this flux will attract the shoe with much force, and brake will apply.