2. Rotor

2.1 Sheet metal and shaft connection

The rotor of a DC machine is subjected to a rotating magnetic field. The magnetic circuit is therefore of laminated construction, to reduce iron losses. The laminations are of soft magnetic quality (steel) or high quality (silicon steel); the most commonly used are M 330-50 A (thickness 0.5 mm) and M 600-65 A (thickness 0.65 mm). They are insulated on both sides with organic varnish or aluminum phosphate.

A distinction is made between two types of construction: single-piece plates for rotors with diameters of less than 1,200 mm, and segmented plates for larger diameters.