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EP-4738658-A1 - LOW-RESISTANCE AND LOW-SPEED MOTOR-GENERATOR

EP4738658A1EP 4738658 A1EP4738658 A1EP 4738658A1EP-4738658-A1

Abstract

The subject of the present invention is a low-resistance and low-speed motor-generator comprising a rotor comprising an outer magnetic ring (1) and an inner magnetic ring (2), and a stator comprising a serpentine coil (4), arranged between the outer magnetic ring (1) and the inner magnetic ring (2), wherein the at least one magnetic ring constitutes a multipole monolithic magnet. In a preferred variant of the present invention, the serpentine coil (4) comprises at least one layer of an electrical conductor and at least one layer of a material with good magnetic permeability which are arranged alternatingly, which can be referred to as an air serpentine coil with an "inner core".

Inventors

  • JUSZKO, RAFAL
  • Zemlak, Arkadiusz
  • Zajdel, Jakub

Assignees

  • VP System Sp z o.o.

Dates

Publication Date
20260506
Application Date
20241031

Claims (9)

  1. A motor-generator comprising: a rotor comprising an outer magnetic ring (1) and an inner magnetic ring (2), and a stator comprising a serpentine coil (4), arranged between the outer magnetic ring (1) and the inner magnetic ring (2), wherein the at least one magnetic ring constitutes a multipole monolithic magnet.
  2. The motor-generator acc. to claim 1, wherein both magnetic rings (1, 2) constitute multipole monolithic magnets.
  3. The motor-generator acc. to any one of claims 1-3, wherein the serpentine coil (4) constitutes a coreless coil.
  4. The motor-generator acc. to any one of claims 1-3, wherein the serpentine coil (4) comprises at least one layer of an electrical conductor and at least one layer of a material with good magnetic permeability which are arranged alternatingly.
  5. The motor-generator acc. to claim 4, wherein the serpentine coil (4) comprises from 10 to 30, preferably 25, layers of the electrical conductor and the same number of the layers of the material with good magnetic permeability which are arranged alternatingly.
  6. The motor-generator acc. to claim 4 or 5, wherein the electrical conductor constitutes copper and the material with good magnetic permeability constitutes nickel or iron.
  7. The motor-generator acc. to any one of claims 4-6, wherein the layer of the material with good magnetic permeability is electroplated onto the layer of the electrical conductor.
  8. The motor-generator acc. to any one of claims 4-6, wherein the layer of the material with good magnetic permeability and the layer of the electrical conductor constitute alternatingly arranged tapes.
  9. The motor-generator according to any one of the preceding claims, constituting a generator for a wind turbine for the production of electrical energy from low wind velocities of 1-8 m/s.

Description

The subject of the present invention is a low-resistance and low-speed motor-generator. An example method for assembly of a brushless motor-generator is known from the document WO2018064370A1. The disclosed motor-generator comprises a rotor and a stator. The rotor is constructed of two concentric, spaced-apart steel rotor cylinders which are attached to a hub. The hub is supported by a central axle arranged in rotation-enabling bearings. Circumferential arrangements of permanent magnets with variable polarity are attached to the rotor cylinders. This document discloses the utilization of a so-called air core, where the windings are arranged in an air gap, without the employment of a ferromagnetic core. Such a construction reduces magnetic losses, such as hysteresis and eddy currents. In the disclosed process for assembly, a winding with the air core is formed by covering a non-magnetic mold of the winding with a tacky layer of an adhesive and then winding the windings onto a winding pattern onto the non-magnetic mold by employing a wire composed of multiple separately insulated strands of electrical conductors which are electrically connected in parallel. The document WO16044408A1 discloses a motor with high efficiency which utilizes laminated sheet windings (LSW). The disclosed design is more compact, lighter and generates less heat than the traditional motors. The laminated sheets form stationary windings around which permanent magnets rotate, generating a magnetic field. The described design of the magnets relates to complex arrangements consisting of magnets with various shapes. The magnets may have a cuneal (trapezoidal or prismatic), rectangular, cylindrical or arcuate shape. According to the document, it is best to connect the magnets to each other by means of a non-conductive adhesive at their interfaces. The motor may be configured in a radial or axial arrangement. In this technology, large air gaps are used, which increases the performance. The known low-resistance generators are characterized by a different structure from the classical motors and generators. The primary difference is the absence of an iron core in or around the space of the stator coils which interacts with the magnetic field induced by the rotor magnets. In effect, the motor and generator with the classical structure cause additional resistance originating from a steel core, the role of which is to close the magnetic field of the rotor behind the stator coils. Typically, the foregoing of the iron core enforces the employment of an additional row of magnets on the other side of the stator to create an appropriate magnetic circuit. A method for making a stator coil is known from the document US4883981A which comprises the process of winding an electrical conductor (a copper wire) around pins disposed on a flat surface. Methods of making a serpentine coil are also known where initially turns of an electric conductor are wound into the shape of a circle unfolded on movable pins laid on a flat surface, which is then followed by having the pins alternatingly extend inwardly and outwardly of the resulting circle, which bends the coil into the shape of a flat, horizontal serpentine coil. In other known solutions, extendable rolls of a winding device are used instead of the movable pins. A method for producing a bonded magnet is known from the international patent application WO2011126023A1 which allows to reduce the costs and improve the effectiveness of the production of an annular bonded magnet. In the described document, in-mold magnetization occurs, that is, a magnetic field is applied to a mixture of a magnetic powder and a resin in the course of molding in a mold. Magnetic particles are oriented during the molding. According to this document, a powder of rare earth metal magnets and a resin as a binding material are used for the production of the bonded magnets. This resin may be thermosetting or thermoplastic, depending on the molding process. In particular, resins such as epoxy, unsaturated polyester, phenolic, polyamide, polyamideimide, and other resins were mentioned. Materials such as resin, which undergoes softening or melting during heating, are employed in this process, which enables the magnetic orientation of the powders in the structure. The process does not require high temperatures typical for sintered magnets. It is advisable to use such magnets for a multipole motor, allowing for miniaturization and weight savings. However, the option of using such magnets in generators, especially low-resistance generators in which no amplification of the magnetic field takes place through the winding of the coil onto a core with high magnetic permeability, is not advised. The bonded magnet described above constitutes an example of a multipole monolithic magnet. The multipole monolithic magnets are characterized by having multiple poles, connected in the production process such that they constitute a uniform, integral structure. Th