Rotating alternating-current machine e.g. tetra-polar induction motor, has magnetic yoke comprising variable section in axial plane of machine and formed by assembling small unitary elements made of ferromagnetic material

摘要

The machine has a rotor (31) mounted rotatably about an axis (X) relative to a stator (32), where an air gap (13) is formed between the stator and the rotor. The stator and/or the rotor comprise a magnetic yoke (32') carrying an electric coil whose windings are extended axially. The magnetic yoke comprises a variable section in an axial plane of the machine. The yoke is formed by assembling small unitary elements made of ferromagnetic material such as magnetic metal powder containing electrically insulated iron particles, transformed by molding, pressing, sintering or injection technique.