Pole sheets from Waelzholz are used as end plates for the lamination stacks in electric motors and generators. Thanks to their mechanical strength, they enable the stacks to be operated safely at high speeds and with correspondingly high centrifugal forces.

Electrical steel strip for high-performance electric motors and generators is often used in a thickness of between 0.1 and 0.35 millimeters. Especially at high frequencies, the thin material in the stator and rotor lamination stacks keeps eddy current losses low and therefore improves power output. High rotational speeds generate enormous centrifugal forces, however, which act on the lamination stack. To ensure that lamination stacks can withstand these forces, cold-rolled pole sheets with high yield strengths are used as the last layer on both ends of the stacks. The pole sheets with defined mechanical properties allow the stacks to be clamped and tensioned so that higher speeds can be safely achieved.

Another purpose of the pole sheets is to feed the magnetic fields back into the lamination stack – when the rotor spins, it cuts through the stator’s magnetic fields, which generates eddy currents and thus a loss of power. Pole sheets minimize this effect by reducing the corresponding expansion of the magnetic field.