Classifications

• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02K—DYNAMO-ELECTRIC MACHINES
  • H02K1/00—Details of the magnetic circuit
  • H02K1/06—Details of the magnetic circuit characterised by the shape, form or construction
  • H02K1/12—Stationary parts of the magnetic circuit
  • H02K1/14—Stator cores with salient poles
  • H02K1/146—Stator cores with salient poles consisting of a generally annular yoke with salient poles
  • H02K1/148—Sectional cores
• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02K—DYNAMO-ELECTRIC MACHINES
  • H02K15/00—Processes or apparatus specially adapted for manufacturing, assembling, maintaining or repairing of dynamo-electric machines
  • H02K15/02—Processes or apparatus specially adapted for manufacturing, assembling, maintaining or repairing of dynamo-electric machines of stator or rotor bodies
  • H02K15/021—Magnetic cores
  • H02K15/022—Magnetic cores with salient poles
• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02K—DYNAMO-ELECTRIC MACHINES
  • H02K2201/00—Specific aspects not provided for in the other groups of this subclass relating to the magnetic circuits
  • H02K2201/15—Sectional machines

Definitions

• the present invention relates generally to electrical machines with axial flow.
• stator of an axial flow electric machine comprising a cylindrical body around a longitudinal axis, which has an end face, teeth distributed on the end face of the body around the axis longitudinal, and at least one coil comprising a casing of electrically insulating material which surrounds one of said teeth, and an electrically conductive wire which is wound around said casing, said tooth comprising a first part fixed with respect to said body and at least a second part which is attached to the first part and which is made of magnetic material.
• Conventional stators comprise a one-piece body, with an annular part and teeth distributed along the periphery of one of the faces of the annular part.
• the conductive wire is wound directly around the teeth, which requires a large spacing between the teeth and results in a sparse winding.
• a drawback of this solution lies in the process of manufacturing and assembling such a stator. This solution requires the provision of grooves both in the tooth and in the casing of the coil and then force-clip each additional part.
• the present invention provides a stator as defined in the introduction, in which the second part extends axially, along the longitudinal axis, over the entire height of the first part, and in that the second part has at least one protruding rib which extends lengthwise along an axis orthogonal to the longitudinal axis, on one side of the second part which is located opposite of the first part.
• the stator tooth thus comprises a first integral part of the body and forming with the latter a one-piece assembly, and at least a second attached part.
• the circulation of the magnetic flux is improved.
• the magnetic flux along the longitudinal axis entering through the upper face of the second part can travel all the way to the stator body without changing direction.
• Having a second part that extends axially along the longitudinal axis over at least the entire length of the first part therefore decreases the magnetic resistance, between the second parts, the body and the first parts, and increases the performance of a motor based on such a stator.
• the first part and the second part are in contact with each other along a flat surface, which simplifies the manufacturing process of the stator.
• the second part does not need to be clipped on either side.
• This simplification of assembly is very advantageous with a view to mass production.
• the absence of a notch in the insulating casing of the coil makes it possible to reduce the volume of the insulating material between two teeth and therefore to bring the teeth closer to each other.
• stator according to the invention taken individually or in any technically possible combination, are as follows:
• the second part is profiled with a constant section along an axis which is orthogonal to the longitudinal axis
• the second part has a width, along an axis orthogonal to the longitudinal axis and which passes through said tooth, which is greater than the width of the first part along said axis, and the second part extends from side to side. other of the first part,
• the first part has at least one projecting rib which extends lengthwise along an axis orthogonal to the longitudinal axis, on one side which is located opposite the second part.
• the invention also provides a method of assembling a stator of an axial flow electric machine, which stator comprising a cylindrical body about a longitudinal axis and which has an end face, a plurality of teeth which are distributed over said end face around said longitudinal axis and at least one of which comprises a first part fixed relative to said body and at least one second attached part which extends axially along the longitudinal axis over at least the entire length.
• the second part having at least one protruding rib which extends lengthwise along an axis orthogonal to the longitudinal axis, on one side of the second part which is located opposite the first part and being made of magnetic material, and the stator finally comprising at least one coil comprising a casing of electrically insulating material and a wire electrically conductive, the process comprising, in order:
• the invention also provides a second method of assembling a stator of an axial flow electric machine, which stator comprises a one-piece cylindrical body around a longitudinal axis and which has an end face, a plurality of teeth which are distributed over said end face around said longitudinal axis and of which at least one comprises a first integral part of said body and a second attached part which extends axially along the longitudinal axis over at least the entire length of the first part, the second part having at least one projecting rib which extends lengthwise along an axis orthogonal to the longitudinal axis, on one side of the second part which is located opposite the first part, the first part having at least one protruding rib which extends lengthwise along an axis orthogonal to the longitudinal axis, on one side which is located opposite the second part, the second part being made of a magnetic material ue, the stator finally comprising at least one coil comprising a casing of electrically insulating material and an electrically conductive wire, the method being characterized in that it
• a step of placing the coil around the first part of the tooth comprising a first, a first translational movement of the coil, and a second rotational movement of the body, until the side face which has a rib protruding either in contact with the casing,
• the two assembly methods according to the invention greatly facilitate the positioning of the coil support on stator teeth having ribs or fins.
• the second method makes it possible to manufacture a stator comprising teeth in only two parts, each part having a fin or rib, thanks to to the rotational movement of the stator body.
• FIG. 1 is a schematic, assembled perspective view of the stator body and its teeth
• FIG. 2 is an exploded schematic view of the body and teeth of the stator of FIG. 1;
• FIG. 3 is a detailed schematic view of a tooth of the stator of Figure 1;
• FIG. 4 is a schematic view of the tooth of FIG. 3 and of its winding
• FIG. 5 is a detailed schematic view of an alternative embodiment of a tooth of the stator of Figure 1;
• FIG. 6 is a schematic sectional view of part of another alternative embodiment of a tooth of the stator of Figure 1, shown at a first stage of assembly;
• FIG. 7 is a schematic sectional view of the tooth of Figure 6, shown in a second stage of assembly.
• stator comprises a cylindrical body 101 of revolution about a longitudinal axis A1.
• axially axially
• radially axially
• radially radially
• this body 101 has more precisely the shape of a flattened ring, of height much less than its diameter.
• the body 101 thus has an internal cylindrical face 102, an external cylindrical face 103 and two end faces 104 planar.
• the body 101 of the stator is made of magnetic material. It is for example produced by a stack of steel sheets with a thickness less than or equal to a millimeter. These metal plates are here curved and stacked radially. They run the full height of the body 101. Thus, the losses in the stator due to eddy currents are limited.
• the stator also has teeth 120 which are distributed over one of the two end faces 104 of the body 101 and on which will be attached coils of electrically conductive wires.
• At least one of these teeth 120 has two parts, a first part 130 fixed to the body 101, and at least a second part 140 attached.
• each tooth 120 is composed of at least two parts.
• each tooth 120 comprises a first part 130 and two second parts 140 attached to the first part, on either side thereof.
• the teeth 120 are distributed evenly on the end face 104 around the longitudinal axis A1.
• the teeth 120 are further separated from each other by radial notches 150.
• the notches 150 each have a plane of symmetry which contains the longitudinal axis A1.
• the first parts 130 of the teeth 120 rise from the body 1 10 and generally have the shapes of prisms.
• Each first part 130 thus has a concave inner face which extends in the extension of the inner face 102 of the body 101, a convex outer face which extends in the extension of the outer face 103 of the body 101, a flat upper face and parallel to the end face 104 of the body 101 and two side faces 131.
• Each of these two lateral faces 131 extends parallel to the lateral face which faces it (this lateral face which faces it belonging to the first part 130 of the neighboring tooth 120).
• the first parts 130 of the teeth 120 are part of the same aforementioned stack of sheet metal as the body 101.
• the second parts 140 of the teeth 120 can be shaped from the same block of material as that forming the body 101 and the first parts 130 of the teeth 120.
• the second parts 140 can be made by a radial stack of magnetic sheets .
• the advantage of making the first and second parts of the teeth 120 and of the stator body 101 by stacking sheets is that the stator body 101 having the first parts 130 of teeth can be made by a winding method of one. same sheet according to the so-called "slinky" method and therefore only requires a punching machine.
• the making of the second parts 140 of the teeth can be done using just one other punching machine.
• they can be made from another magnetic material such as a metal powder, grain oriented electrical steel or a stack of steel sheets different from that of the body 101.
• the second parts 140 of the teeth 120 may have variable shapes, such as substantially parallelepipedal shapes (case of Figure 3) or triangular prism shapes (case of Figure 5).
• Each second part 140 nevertheless has a first planar face which is applied against a lateral face 131 of a first part 130 of the corresponding tooth 120.
• This flatness has the advantage of simple and inexpensive machining.
• Each second part 140 further has a second planar face 145 which is applied against the end face 104 of the body 101.
• the end face 104 of the body 101 may have indentations facilitating the positioning of the second tooth portions 140 when mounting the stator.
• These imprints are for example radial grooves having the same width as the second planar face 145.
• the teeth 120 are identical to each other.
• the first parts 130 and second parts 140 are at least symmetrical, even preferably identical to each other. It is possible to use different teeth 120 within the same stator, but this would complicate its design and mass production.
• the second part 140 of each tooth 120 extends axially over the entire height of the first part 130 of this tooth, which best limits the magnetic resistance of the teeth 120.
• each second part 140 is profiled along a radial axis A2, A3 (orthogonal to the longitudinal axis A1), that is to say that each second part 140 has a constant section along this axis (to within 5% if one considers the areas of the external and internal faces of each second part 140).
• each second part 140 has a substantially parallelepipedal shape and extends axially over a height identical to that of the first part 130 of the tooth 120. This makes it possible, as explained above, to facilitate the steps stator assembly and improve the flow of magnetic flux.
• Each second part 140 extends radially over a width at least equal, here greater than that of the first part 130 of the tooth 120. In this way, each second part 140 extends on either side of the first part 130 of the tooth 120. Each second part 140 extends radially as a variant over a width very slightly less than that of the first part 130. However, this variant is less advantageous magnetically.
• each first tooth part 130 is flanked by two second parts 140 symmetrical with respect to each other.
• each second part 140 has at least one rib (here two ribs 161, 162) projecting from its face located opposite the first part 130.
• Each rib extends in length, along the radial axis A2, A3, over the entire width of the second part.
• An upper rib 161 is located at the level of the upper face 144 while a lower rib 162 is in contact with the end face 104 of the body 101.
• the upper rib 161 has an upper face located in the embedding of the upper face of the rest of the second part 140 of the tooth 120, and a lower face inclined with respect to the latter, towards the outside of the tooth 120.
• the lower rib 162 has a lower face located in the embedding of the lower face of the remainder of the second part 140 of the tooth 120, and an upper face inclined relative to the latter.
• the width of a rib 161, 162 is less than the half-width of the notch 150 separating two teeth 120. Its height (measured axially) is between 5 and 20% of the height of a tooth 120.
• the ribs in particular the upper ribs 161, are very useful since they reduce the space between the teeth 120, which thus decreases the variations in magnetic fields at the level of the rotor and reduces the associated power losses.
• the second parts 140 have different shapes.
• each second part 140 has the shape of a triangular prism, with two lateral faces inclined with respect to one another and a width which decreases from its upper face towards the body 101.
• the lateral faces of the first part 130 of the tooth 120 are then inclined at an angle complementary to that of the second parts 140, so that the teeth 120 have external shapes identical to those of the teeth 120 shown in FIG. 3. .
• This configuration has the advantage of facilitating the step, which will be described later, of winding the conductive wire.
• each tooth 120 is intended to be surrounded by a coil 180 comprising a casing 190 and a conductive wire 181 wound around the casing 190.
• the conductive wire 181 is for example a copper wire.
• the envelope 190 is in turn designed in an insulating material, for example a plastic material. It is possible to envision this envelope being molded in one piece. However, each envelope is preferably made up of two parts molded separately and then assembled. Any assembly means known to those skilled in the art can be considered.
• the casing 190 has an internal shape allowing it to adapt, up to the assembly clearance, to the shape of a tooth 120. It thus has four walls, including an internal wall 192 facing the longitudinal axis A1, an outer wall 191 and two side walls 193.
• the envelope 190 is thinner at its side walls 193 than at its internal 192 and external 191 walls. It thus has, for example, a thickness of between 0.5 and 2 mm along its side walls 193 and a thickness of between 4 and 5 mm along its outer 191 and inner walls 192. This variation in thickness makes it more resistant, in particular with a view to winding the conductive wire 181 on the external face 191.
• each tooth 120 has a first part 130 and a single second part 140.
• the second parts 140 are all placed on the same side of their respective first part 130.
• the second part 140 has a shape identical to one of those shown in Figure 3, except that it has only one rib located along its upper face 144.
• the first part 130 of the tooth 120 then also comprises a rib 171, positioned along its top, projecting from its face opposite to that which is intended to receive the second part 130.
• This rib 171 is shaped so that the two ribs of each tooth 120 extend symmetrically with respect to a radial plane passing through the longitudinal axis A1.
• Figure 4 shows an assembly, consisting of a tooth 120 and a coil 180 according to the first embodiment, once assembled. Several methods can be used to achieve this result. All of these methods assume that the body 101 and the first parts 130 of the teeth 120 have been fabricated, as well as the second parts 140 of the teeth.
• a first example of a method begins with the insertion of the second parts 140 of each tooth 120 inside a casing 190 of the coil 180 (step a).
• the second parts 140 are for example glued to the envelope 190.
• the envelope consists of two separate parts, it is possible to envisage gluing a first part of the envelope 190 on one of the two second parts. 140 of tooth 120, then to glue a second part of the envelope 190 on the other second part 140 of the tooth 120, and finally to fix the two parts of the envelope 190 between them.
• This method also has the advantage of being able to mold two identical parts of the casing 190, and therefore of requiring only one mold.
• the conductive wire 181 is then wound around the envelope 190 of the coil 180 (step b). This winding is achieved by placing the casing 190 and the second parts 140 on a rotating support. By rotating on itself, the envelope 190 drives the conductive wire 181. Slower and simultaneous translational movements of the casing 190 allow the conductive wire 181 to be wound up to the full height of the casing 190.
• step c the assembly consisting of the coil 180 and the second part 140 is fixed to the first part 130 of the tooth.
• step b) one can for example use a support which has an external shape adapted to the internal shape of the envelope 190, and which has an internal shape adapted to a rotating part.
• This support will then have the additional function of preventing deformation of said assembly.
• This support must then be removed when inserting the assembly consisting of the coil 180 and the second parts 140 on the first part 130 of the tooth 120.
• steps a) and b) is reversed. . This variant eliminates the need for a specific tool to hold the teeth when winding the casing.
• This example begins with the winding of the conductive wire 181 around the envelope 190 of the coil 180 (step a). This winding is achieved by placing the envelope 190 on a rotating part. By rotating on itself, the envelope 190 drives the conductive wire 181. Here again, combined translational movements of envelope 190 are applied.
• the coil 180 is then placed around the first part 130 of the tooth 120 (step b, FIG. 6), it is placed so as to be able to insert the second part (s) 140 between the first part 130 and the envelope 190.
• the second part or parts 140 are inserted into the space left free between the envelope 190 and the first part 130 (step c).
• the insertion of the coil 180 around the first part 130 of the tooth 120 is broken down into two movements: a first translational movement of the coil, the result of which is shown in FIG. 6; and a second rotational movement of the body 101, until the face 131 is in contact with the casing 190, that is to say until the lateral face 131 of the first part 130, that which has a protruding rib, or in contact with the side wall 193 of the casing 190.
• the final result, after insertion of the second part 140 is shown in FIG. 7.
• the second part or parts 140 are fixed to the first part 130 of the tooth and to the casing of the coil (step d).
• step a) a support of suitable shape to avoid any deformation of the casing 190, and one can use in step d) any type of fixing means.

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• Engineering & Computer Science (AREA)
• Power Engineering (AREA)
• Iron Core Of Rotating Electric Machines (AREA)
• Manufacture Of Motors, Generators (AREA)

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• 2019
  • 2019-05-21 FR FR1905327A patent/FR3096522B1/fr active Active
• 2020
  • 2020-04-23 WO PCT/EP2020/061284 patent/WO2020233936A1/fr not_active Ceased
  • 2020-04-23 EP EP20719468.9A patent/EP3973614A1/de active Pending

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