How do electromagnetic brakes work?
Release Date:28/03/2016
A typical electromagnetic brake has
three elements in its construction – a magnetic field comprising of a
coil and a shell, an armature and the hub. When the brakes are applied,
the armature is attracted to the magnetic field developed by the coil. Simultaneously, a torque working in the opposite direction is
transferred into the field to counteract the effect of the magnetic
field. As the strength of the field falls, the vehicle begins to slow
down and eventually stops. The disengagement process begins as soon as
the vehicle stops. As the magnetic flux degrades rapidly, the armature
is brought to its initial position ready to work again. This process is
quite rapid and usually takes less than three seconds to complete. The
smooth working of the coil is crucial to the effective functioning of
the electromagnetic brake as it produces the magnetic field. The whole
assembly has to be protected against extremes of temperature as well as
wear and tear, as both these factors are detrimental to the functioning
of the brakes. Electromagnetic brakes are now used in airplane braking systems in addition to extensive use in train and tram braking systems.
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