Abstract: The resolver with variable magnetic coupling comprises a stator constituted by first and second stacks of laminations disposed coaxially around a rotor having an axis of rotation, and spaced apart along said axis. The rotor is constituted by first and second stacks of laminations spaced apart from each other along the axis of rotation of the rotor and in register with the first and second stator stacks of laminations, respectively. The first and second rotor stacks of laminations are angularly offset from each other and each couples magnetically with the stator via an outer peripheral surface that defines at least two regularly spaced-apart lobes, thus enabling a resolver to be produced that is of low cost and that provides very good accuracy.

Abstract: A linear motor comprising a first portion having: a primary magnetic circuit comprising N.sub.e slots alternating with N.sub.d teeth, with N.sub.e =N.sub.d, a multiphase electrical winding having 2P poles being placed inside said slots and, at an instant t when fed with AC, producing an undulated magnetic field of length l and of P periods along the length l of the magnetic circuit covering the N.sub.e slots and the N.sub.d teeth; and a second portion, disposed facing the first portion and separated therefrom by a plane air gap, said second portion having a length L=l+x, where x is the length of relative displacement between the two portions relative to each other, said second portion constituting a secondary magnetic circuit; wherein, facing said air gap, said secondary magnetic circuit comprises a series of teeth and slots along its entire length L, wherein said first portion comprises, along said air gap, and fixed to the primary magnetic circuit at the end of its teeth and its slots, a series of 2N.sub.

Abstract: A synchronous motor including permanent magnets inserted in a rotor, said permanent magnets having azimuth positions within said rotor and having radial magnetization, said rotor co-operating with a stator so as to define an air gap, said rotor and said stator being defined by poles, wherein flux produced by said permanent magnets propagates within the rotor along a first magnetic path F3 situated between said poles, said first magnetic path F3 having a reluctance lying in the range 0.5 times to 10 times the reluctance offered to the flux produced by said permanent magnets and propagating via said air gap.