Pole piece

A pole piece is a component of a material with high permeability, for example iron. He used to let emerge the magnetic field lines of a permanent magnet or a coil in a defined shape and distribute.

Thus, the exciting magnetic field is distributed through a pole piece of a circular segment on the armature, for example in an electric motor. Characterized the course of the magnetic flux density along the anchor round homogenized. Not only has the stator pole shoes, but also the armature of the DC motor or the rotor of turbo-generators. The latter generates the excitation field in an elongated coil, the pole shoes contributes to distribute the field at the outer cylindrical surface of the rotor.

For special designs, such as the linear motor, the pole pieces are not circular segment, but just. Instead of a rotating movement, a linear movement is generated.

In electrodynamic loudspeakers, the pole pieces pole plates hot; to produce a radial field in the annular gap.

Pole shoes of the field windings of AC motors, DC motors of runners and watt-meters must be laminated to keep eddy current losses. Also stators alternators have magnetics, for this reason, the pole pieces.