Abstract

The present invention concerns a method for coating particles of ferromagnetic material with a layer of NiZn ferrite. Said method comprises: - providing particles of ferromagnetic material; - activating the surface of the particles of ferromagnetic material; - coating the particles of ferromagnetic material with ferrite precursors; and - recovering the particles of ferromagnetic material coated in this way. The method can further comprise the formation of an intermediate layer of silica at the surface of the particles prior to coating. The present invention also concerns particles that can be obtained by said method, a method for producing a sintered article from said particles and the sintered article in question.

IPC Classes  ?

• B22F 1/00 - Metallic powderTreatment of metallic powder, e.g. to facilitate working or to improve properties
• B22F 1/02 - Special treatment of metallic powder, e.g. to facilitate working, to improve properties; Metallic powders per se, e.g. mixtures of particles of different composition comprising coating of the powder
• B22F 3/12 - Both compacting and sintering
• B22F 9/20 - Making metallic powder or suspensions thereofApparatus or devices specially adapted therefor using chemical processes with reduction of metal compounds starting from solid metal compounds
• H01F 1/24 - Magnets or magnetic bodies characterised by the magnetic materials thereforSelection of materials for their magnetic properties of inorganic materials characterised by their coercivity of soft-magnetic materials metals or alloys in the form of particles, e.g. powder pressed, sintered, or bound together the particles being insulated

Abstract

A separately excited electric machine having a stator provided with at least one exciter unit and a rotor provided with strips. Each exciter unit comprises two secondary magnetic circuits and one primary magnetic circuit. Each secondary magnetic circuit comprises a stator exciter winding and two annular yokes provided with teeth. The primary magnetic circuit comprises a rotor exciter winding and an annular ring. First magnetic fluxes generated by the primary magnetic circuit circulate around loops in each strip and second magnetic fluxes generated by the secondary magnetic circuits circulate around loops in the strips, the teeth, and the ring. Each strip thus has a first north pole and a first south pole, with the teeth comprising in alternation second north poles and second south poles.

IPC Classes  ?

• H02K 19/12 - Synchronous motors for multi-phase current characterised by the arrangement of exciting windings, e.g. for self-excitation, compounding or pole-changing
• H02K 1/14 - Stator cores with salient poles
• H02K 3/12 - Windings characterised by the conductor shape, form or construction, e.g. with bar conductors arranged in slots
• H02K 19/20 - Synchronous generators having windings each turn of which co-operates only with poles of one polarity, e.g. homopolar generators with variable-reluctance soft-iron rotors without winding
• H02K 19/06 - Motors having windings on the stator and a variable-reluctance soft-iron rotor without windings, e.g. inductor motors
• H02K 19/10 - Synchronous motors for multi-phase current

Abstract

An electric machine includes a stator and a rotor, with the stator being equipped with at least one annular exciter unit that includes a coil and at least two annular yokes, with the rotor being equipped with a structure and at least one annular receiver unit. Each receiver unit includes at least two rows of magnets. Two sides of each yoke include teeth distributed angularly in a regular manner, and the teeth of the two adjacent yokes fit onto a face of the exciter unit, alternately forming north poles and south poles. Each row of the magnets is positioned opposite one face, forming an air gap with the exciter unit, with the electric machine thus including at least two air gaps, with a 3D magnetic flux thus circulating inside the said electric machine, dividing and regrouping itself in the vicinity of the magnets and of the yokes.

IPC Classes  ?

• H02K 1/14 - Stator cores with salient poles
• H02K 21/22 - Synchronous motors having permanent magnetsSynchronous generators having permanent magnets with stationary armatures and rotating magnets with magnets rotating around the armatures, e.g. flywheel magnetos
• H02K 21/24 - Synchronous motors having permanent magnetsSynchronous generators having permanent magnets with stationary armatures and rotating magnets with magnets axially facing the armatures, e.g. hub-type cycle dynamos
• H02K 1/18 - Means for mounting or fastening magnetic stationary parts on to, or to, the stator structures
• H02K 3/52 - Fastening salient pole windings or connections thereto
• H02K 15/02 - Processes or apparatus specially adapted for manufacturing, assembling, maintaining or repairing of dynamo-electric machines of stator or rotor bodies
• H02K 21/02 - Synchronous motors having permanent magnetsSynchronous generators having permanent magnets Details
• H02K 21/12 - Synchronous motors having permanent magnetsSynchronous generators having permanent magnets with stationary armatures and rotating magnets
• H02K 21/14 - Synchronous motors having permanent magnetsSynchronous generators having permanent magnets with stationary armatures and rotating magnets with magnets rotating within the armatures

Abstract

An electric machine including a stator that is provided with at least one exciter unit including a coil, at least two annular yokes and at least one row of intermediate pieces, and a rotor having a structure and at least one receiver unit including at least two series of at least two rows of magnets. Two sides of each yoke include the first teeth, fitting with the intermediate pieces on a face of the exciter unit and alternatingly forming the second north poles and the second south poles. Each series is positioned opposite one face, forming an air gap with the exciter unit, with the electric machine thus including at least two air gaps, with a flux thus circulating inside the electric machine, dividing and regrouping itself in the vicinity of the magnets and of the yokes.

IPC Classes  ?

• H02K 21/12 - Synchronous motors having permanent magnetsSynchronous generators having permanent magnets with stationary armatures and rotating magnets
• H02K 1/14 - Stator cores with salient poles
• H02K 21/24 - Synchronous motors having permanent magnetsSynchronous generators having permanent magnets with stationary armatures and rotating magnets with magnets axially facing the armatures, e.g. hub-type cycle dynamos

Abstract

The invention relates to a homopolar machine, comprising: a rotor (102); a stator (106) relative to which the rotor (102) is intended to rotate, comprising windings (112A, 112B, 112C, 112D, 112E) each intended to have an angular current (iA, iB, iC, iD, iE) pass therethrough in order to generate a magnetic field in the rotor (102); and a current generator (114) for supplying the angular currents (iA, iB, iC, iD, iE) passing through the windings (112A, 112B, 112C, 112D, 112E). The windings (112A, 112B, 112C, 112D, 112E) number at least four, and angular currents (iA, iB, iC, iD, iE) form a multiphase current having a number of phases equal to the number of windings (112A, 112B, 112C, 112D, 112E).

IPC Classes  ?

• H02K 1/14 - Stator cores with salient poles
• H02K 19/10 - Synchronous motors for multi-phase current

Abstract

Homopolar electric machine, characterized in that its structure is double, its rotor and its stator being simultaneously homopolar, and in that it comprises a stack of pairs of simple homopolar stators, forming monophasing elementary machines, or in a reverse version, said elementary machines being powered with AC current; the rotor is common to all these stators, and is passive, that is to say composed completely or partially of ferromagnetic materials.

IPC Classes  ?

• H02K 19/20 - Synchronous generators having windings each turn of which co-operates only with poles of one polarity, e.g. homopolar generators with variable-reluctance soft-iron rotors without winding
• H02K 19/06 - Motors having windings on the stator and a variable-reluctance soft-iron rotor without windings, e.g. inductor motors
• H02K 16/04 - Machines with one rotor and two stators

Abstract

Tooth (1) for homopolar motor, characterized in that it comprises a gap face (6) opposite a facing surface, a gap distance d(9) measured between said surface and said gap face (6) being such that: - over a first tangential distance, measured in a radial plane from a median axial plane (Po) of the tooth (1), the distance d(θ) is equal to a minimum eO; next, - over a second complementary tangential distance, the distance d(θ) increases progressively; where θ is an electric angle.

IPC Classes  ?

• H02K 1/14 - Stator cores with salient poles
• H02K 1/24 - Rotor cores with salient poles
• H02K 29/03 - Motors or generators having non-mechanical commutating devices, e.g. discharge tubes or semiconductor devices with a magnetic circuit specially adapted for avoiding torque ripples or self-starting problems

Abstract

Method making it possible to provide data relating to the position of a rotor of an electric machine, characterized in that it comprises: • the application of a voltage (V123) by an electronic variator to an electric machine, said electronic variator being linked to said electric machine; • the consumption by the electric machine of a current (I123) which can be determined on the basis of (V123) by means of a matrix relation; • the determination of the temporal phase shift between said current (I123) and the voltage (V123); • the determination of the data relating to the position of the rotor of the electric machine as a function of said phase shift which makes it possible to deduce the amplitude of the current (I123) as well as the position of the equivalent rotor flux seen from the stator.

IPC Classes  ?

• H02P 6/18 - Circuit arrangements for detecting position without separate position detecting elements
• H02P 7/282 - Arrangements for regulating or controlling the speed or torque of electric DC motors for regulating or controlling an individual DC dynamo-electric motor by varying field or armature current by master control with auxiliary power using discharge tubes or semiconductor devices using semiconductor devices controlling field supply only
• H02P 21/00 - Arrangements or methods for the control of electric machines by vector control, e.g. by control of field orientation