Patent ID: 7221071

Claim:
A synchronous electric machine (M), comprising an armature (A) and an inductor (B) between which is defined an air gap (G); the armature (A) having at least one pair of poles (N, S); the inductor (B) having, for each pair of poles (N, S) of the armature (A), n identical ferromagnetic tooth structures ( 20 ) and n slots ( 21 ), alternating with one another and each having at the air gap (G) a respective, essentially constant, extent in the direction of relative displacement between inductor (B) and armature (A); the inductor (B) being provided with a winding (W) housed in the said n slots; the machine (M) being characterised in that: the surface of the armature (A) facing the air gap (G) is divided into 2N elements or samples ( 1 – 12 ), with N being an integer multiple of n, having substantially the same extent in the said direction of relative displacement; each of the said ferromagnetic tooth structures of the inductor having at the air gap a sequence of teeth ( 20 a ) of substantially constant extent along the said direction of relative displacement, separated by at least one pseudoslot ( 21 a ), so that the surface of the inductor for each pair of poles has at the air gap overall N teeth ( 20 a ) separated by N intervals, of which n are constituted by the openings to the air gap of the said n slots and (N-n) are constituted by the openings to the air gap of the said pseudoslots ( 21 a ); each sample ( 1 – 12 ) of the armature (A) having a respective magnetic potential value (τ i ) essentially constant over the extent of the sample; each sample ( 1 – 12 ) of the armature (A) is associated with a respective total value of magnetic permeance (p i ) at the air gap (G) in a predetermined alignment condition or relative position between the inductor (B) and the armature (A) in which the sample extends between the axis of one tooth and the intermediate axis between this tooth and an adjacent tooth at the air gap (G); the armature (A) includes a plurality of magnetically distinct bodies ( 30 , 31 , 32 ; . . . ) of ferromagnetic material, each of which couples at least two armature samples in such a way as to ensure a substantial magnetic equipotentiality; the magnetic potentials (τ i ) of the single samples ( 1 – 12 ) of the armature (A) and the said values of total magnetic permeance (p i ) associated with them being determined according to predetermined criteria, in which the inductor (B) is formed in such a way that it is able to generate a magnetomotive force distribution which is seen by the armature (A) identically in all relative positions which are separated from one another by one slot pitch (P), and in which in the 2N/n possible alignment conditions for each sample ( 1 – 12 ) in a slot pitch (P), the values of all the magnetic parameters (L o , L m , L om , Ψ O , Ψ m ) of the electric machine calculated in the components along two separate axes (o,m) for example in quadrature with one another, fixed to the armature, are substantially equal to one another in the said 2N/n alignment conditions.