Construction and mode of operation

Electromagnetic clutches The stator body 1 contains the fi eld coil 2 , which is a copper coil cast in synthetic resin.The clutch is activated by applying a direct current to the fi eld coil.This creates a magnetic fi eld (red), which electromagnetically attracts the armature disc 4 towards the input drive hub 7 with its friction lining 3 , and so allows torque to be transmitted from the input side to the output.The axially-located output drive hub 6 separates from the input side when the current is cut off. A return spring 5 ensures that the armature disc se-parates from the input hub. 6 5 Depending on the size of the clutch or brake, the installation must provide for an air gap of between 0.2 and 0.5 mm between the drive hub and the armature disc. The purpose of this air gap is to ensure complete separation of the in- put and output drives when no current is applied. 1 2 7 3 4 Electromagnetic brakes Electromagnetic industrial brakes work in a simi-lar manner. The stator body 1 con-tains the fi eld coil 2 , which is a copper coil cast in synthetic resin. When cur- rent is applied, a magnetic fi eld (red) is created, which attracts the armature disc 4 towards the friction lining 3 , and so transmits a braking torque to the output hub 6 .When the current is cut off, the return spring 5 pulls the armature disc back to its original position. 6 5 1 1 2 2 3 3 4 4 5 6

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