Simplified connection electric motor

The use of paired, planar coupled forks with elastic deformation and overmolded sleeves addresses misalignment issues in electric motor connections, providing a robust and efficient high-current transmission system.

FR3170737A1Pending Publication Date: 2026-06-26SONCEBOZ MECHATRONICS BONCOURT SA

Patent Information

Authority / Receiving Office
FR · FR
Patent Type
Applications
Current Assignee / Owner
SONCEBOZ MECHATRONICS BONCOURT SA
Filing Date
2024-12-20
Publication Date
2026-06-26

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Abstract

The invention relates to an electric motor comprising: a stator supporting coils supplied by conductors terminated by conductive blades extending in an axial direction; a printed circuit board having plated-through holes, extending in a plane perpendicular to said axial direction; the connection between conductive blades and said printed circuit board being ensured by forked connection means inserted in said printed circuit board and plugged onto said conductive blades. Furthermore, said forked connection means consists of a pair of parallel planar coupled forks spaced at a distance of between 0.3 and 3 times the thickness of a fork, each fork having two legs forming a fork for the insertion by elastic deformation of a conductive blade.extended at the opposite end by a conductive head with a cross-section smaller than the cross-section of said holes in the printed circuit board for insertion into the printed circuit board from its lower surface oriented towards said stator, each of said pairs of coupled forks being implanted on said printed circuit board by passing through two parallel plated holes, and by soldering on the face of the printed circuit board opposite said stator, and passing at least partially through said plated holes, said printed circuit board having sets of quarter-holes arranged in the projection of said conductive blades of said stator. Figure 1,
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Description

Title of the invention: Simplified connection electric motor

[0001] Electric motor comprising a connection of the stator with the printed circuit by means of conductive coupled forks. Scope of the invention

[0002] The present invention relates to the field of electrical connection of electrical components on a printed circuit board, and in particular to connections for the passage of high currents, typically from 50 to 200 amperes, at voltages from 12 to 72 volts. The invention relates more particularly to the connection of the windings of an electric motor to a printed circuit board.

[0003] Such motors typically comprise a rotor and a stator formed by a yoke with wound stator teeth, requiring an electrical supply. It is known to provide conductive blades, for example made of copper, allowing the power cables to be connected by forked plugs installed during motor assembly. State of the art

[0004] In the prior art, patent FR3045236B1 is known, which proposes an electric motor comprising a printed circuit board having a conductive insert through which connection holes pass and a wound assembly having electrical connections terminated by connection plugs, further comprising connection pieces having a rod whose external cross-section is complementary to the section of said connection holes, the connection piece having at its proximal end a shoulder of a section greater than the section of said connection holes, the opposite end having a slot extending to said shoulder and having on the distal side an opening of width greater than or equal to the section of said connection plugs and at least a narrowing of width less than the section of said connection plugs, to ensure an expansion of the neck of said connection piece engaged in the hole of the printed circuit board insert..

[0005] Patent application DE102015110417 describing a contact element for the electrically conductive connection of a plurality of electrical components, having an elongated basic body having a first axial end and a second axial end, one on the first axial end formed a fork contact for removably fixing a first electrical component, one at the second axial end a fork contact in the shape of or a plug-in contact for the removable fixing of a second electrical component. Disadvantages of prior art

[0006] These solutions are not entirely satisfactory because during assembly, especially robotic assembly, the approach of the printed circuit board and the connection elements towards the stator for the engagement of the forked connectors on the connecting blades can cause unexpected deformations or misalignments in the event of slight offset, which can lead to a defective connection, or even degradation of certain elements.

[0007] In particular, the connection pieces inserted from the top of the printed circuit can be driven out of their housing by the axial force exerted by the movement towards the stator, and the connectors can be deformed by torsion or bending when the direction of the force is not perfectly axial. Solution provided by the invention

[0008] In order to overcome these drawbacks, the present invention relates to an electric motor comprising: - a stator supporting coils powered by conductors terminated by conductive blades extending in an axial direction - a printed circuit board with plated-through holes, extending in a plane perpendicular to said axial direction - the connection between conductive blades and said printed circuit board being ensured by forked connection means inserted into said printed circuit board (300) and plugged onto said conductive blades

[0009] characterized in that: - said forked connection means consists of a pair of parallel, planar, coupled forks spaced at a distance of between 0.3 and 3 times the thickness of a fork, each fork having two legs forming a fork for the insertion by elastic deformation of a conductive blade, extended at the opposite end by a conductive head with a cross-section smaller than the cross-section of said holes in the printed circuit board for insertion into the printed circuit board from its lower surface oriented towards said stator - each of said pairs of coupled forks being mounted on said printed circuit board by passing through two parallel plated holes, and by a solder joint on the face of the printed circuit board opposite said stator, and passing at least partially through said plated holes - said printed circuit board having sets of quarter-holes arranged in the projection of said conductive blades of said stator.

[0010] According to alternative embodiments:

[0011] - the solder passes through the printed circuit board to cover a part of said legs.

[0012] - the solder passes through the printed circuit board to form a bead between the forks planar coupled of a pair

[0013] - said conductive head has a square cross-section, and the holes of said printed circuit present a round section

[0014] - said conductive blades are surrounded by an overmolded sleeve

[0015] - said sleeves have internal guiding zones for the four legs of a pair of coupled conducting forks

[0016] Detailed description of a non-limiting example of embodiment

[0017] The present invention will be better understood upon reading the following description, concerning a non-limiting example of an embodiment illustrated by the accompanying drawings where:

[0018] [Fig-1] [Fig.1] illustrates an exploded view, in three-quarter front perspective, of a electric motor according to the invention

[0019] [Fig. IBIS] [Fig. IBIS] illustrates a perspective view of a pair of forks coupled according to the invention

[0020] [Fig.2] Fig.2 illustrates an exploded view, in three-quarter rear perspective, of the electric motor according to the invention

[0021] [Fig.3] Fig.3 illustrates a detailed view, an exploded view, in perspective of A three-quarter rear view, in partial section, of the electric motor, highlighting specific elements related to the assembly of the conductive blades, the coupled conductive forks, and the printed circuit board.

[0022] [Fig. 4] Fig. 4 illustrates a detailed view, an exploded view, in three-point perspective. Front quarters, in partial section, of the electric motor highlighting specific elements related to the assembly of the conductive blades, the coupled conductive forks and the printed circuit board

[0023] [Fig.5] Fig.5 shows a cross-sectional view of an inserted conducting fork in a metallized hole in the printed circuit board (300)

[0024] [Fig.6] Figure [Fig.6] shows a cross-sectional view of a pair of forks conductive elements (210, 220, 230) inserted into a metallized hole in the printed circuit board (300), in a plane perpendicular to that illustrated by the previous figure. Operating principles

[0025] The invention relates to a connection system which improves reliability, reduces the risks of misalignment and facilitates robotic assembly through the use of pairs of coupled forks (210, 220, 230) of conductive blades (110, 120, 130) oriented axially from the stator of the electric motor (100).

[0026] The principle of the invention relates more specifically to the configuration of the pairs of coupled forks (210, 220, 230) illustrated in Figure [Fig. IBIS]: each consists of two flat forks (211, 212) slightly separated transversely, each fork having two legs (215, 216; 217, 218) adapted to come pinch the blade (110) when it is inserted between the four jambs (215, 216; 217, 218). The legs are extended by conductive heads having two protrusions (255, 256; 257, 258) adapted to be inserted into sets of four plated-through holes (310, 320, 330) in a printed circuit board (300). Inserting the two forks onto the printed circuit board (300) ensures their stability, spacing, and axial orientation, perpendicular to the plane of the printed circuit board (300). When the motor (100) and the printed circuit board (300) are brought together, the blades (110, 120, 130) will come into contact with four points on the corresponding coupled forks (210, 220, 230), thus ensuring improved stability during insertion and preventing unexpected tilting that occurs when contact is made by only two aligned points.

[0027] Figure 1 illustrates an electric motor (100) comprising, in a known manner, a stator and a rotor (not explicitly shown in this exploded view), with coils connected by conductive blades (110, 120, 130). These conductive blades (110, 120, 130) are arranged axially and connect the stator windings to the printed circuit board (300). These blades (110, 120, 130) serve as connectors to transmit electrical energy with high mechanical stability to the traces of the printed circuit board (300) via coupled conductive forks (210, 220, 230).

[0028] The legs of these coupled forks (210, 220, 230) allow insertion by elastic deformation of the blades (110, 120, 130).

[0029] The conductive coupled forks (210, 220, 230) are welded on the opposite face of the stator, ensuring a reliable and durable connection. The weld penetrates the plated holes (310, 320, 330) to reinforce the attachment of the coupled forks and ensure increased robustness of the assembly.

[0030] The conductive blades (110, 120, 130) are inserted into the coupled forks (210, 220, 230) from the axial direction, while the printed circuit board (300) is placed perpendicularly, optimizing mechanical and electrical alignment.

[0031] The conductive blades (110, 120, 130) play a central role in the operation of the electric motor according to the invention. This role is to establish an electrical and mechanical connection between the stator windings and the printed circuit board (300).

[0032] The conductive blades (110, 120, 130) serve as an electrical bridge between the stator windings, which generate or receive the electric current, and the printed circuit board (300), which distributes or regulates this current, via the coupled forks (210, 220, 230). They transmit high currents (typically between 50 and 200 amperes) at voltages of 12 to 72 volts, with minimal electrical losses thanks to their structure made of high-quality conductive materials, such as copper or conductive alloys.

[0033] The conductive blades (110, 120, 130) are specially designed to fit into the elastic coupling forks (210, 220, 230). This elastic deformation insertion system ensures a solid and reliable electrical connection, thanks to the pressure exerted by the legs of the coupling forks (210, 220, 230) on the blades (110, 120, 130), and facilitates quick and automated assembly by eliminating the need for complex soldering on the blades (110, 120, 130) themselves. In addition to their electrical role, the blades (110, 120, 130) provide mechanical assistance by forming a guide point to ensure perfect alignment between the stator and the printed circuit board (300). Their orientation in an axial direction and their rigidity prevent misalignment or tilting during robotic assembly.

[0034] Some variants incorporate overmolded sleeves around the conductive blades (110, 120, 130), reinforcing their stability and facilitating guidance in the coupled forks (210, 220, 230).

[0035] The conductive blades (110, 120, 130), thanks to their mass and material, also contribute to the dissipation of heat generated by the passage of high currents. They thus minimize the risk of overheating, protecting the surrounding components.

[0036] The overmolded insulating sleeves (150, 160, 170), which optionally surround the conductive blades (110, 120, 130), protect the connections against short circuits, guide the coupled forks (210, 220, 230) for perfect alignment and electrically isolate the blades from the other parts of the motor (100).

[0037] These insulating sleeves (150, 160, 170) form rigid or semi-rigid enclosures molded directly around the blades (110, 120, 130). Their shape is optimized to guide the contours of the coupled forks (210, 220, 230), with internal guide zones that ensure precise alignment of the blades with respect to the conductive forks previously soldered to the printed circuit board.

[0038] They can be manufactured in different sizes and sections depending on specific needs (current to be transmitted, space constraints, etc.).

[0039] The sleeves (150, 160, 170) prevent any misalignment of the conductive blades during their insertion into the forks. This function is essential, particularly in robotic assembly processes, where a slight misalignment could damage the components or lead to a faulty connection.

[0040] They enhance the mechanical stability of the blades by reducing vibrations and unwanted movements during motor operation.

[0041] The sleeves (150, 160, 170) act as an insulating barrier, preventing short circuits between the conductive blades (110, 120, 130) or with other surrounding metallic components.

[0042] They also protect the blades from external aggressions, such as humidity, dust, or chemical contaminants, which is crucial for ensuring the system's durability. The internal guide zones of the sleeves (150, 160, 170) are specially configured to precisely align the blades (110, 120, 130) with the fork shanks. This feature guarantees easy insertion and optimal contact without forcing. The sleeves (150, 160, 170) also distribute the pressure exerted by the forks evenly on the blades (110, 120, 130), thus preventing any deformation or localized stress. The sleeves (150, 160, 170) help maintain the blades in a perfectly axial orientation, aligned with the plated-through holes of the printed circuit board (300), facilitating assembly and ensuring reliable electrical contact.

[0043] They prevent lateral or torsional forces that could be applied to the conductive blades during the insertion of the forks or in case of vibrations.

[0044] Thus, the sleeves (150, 160, 170) have a square main opening (151), the length (d2) of which is less than twice the distance (dj) between the edges of the shanks (215, 216; 217, 218) so as to ensure proper insertion of the shanks on either side of the conductive blade. The main opening (151) is extended laterally by a rectangular notch (152) into which the conductive blade (110) extends laterally beyond the main opening (151). The length (d3) of the rectangular notch (152) is less than the distance (di) between the edges of the shanks (215, 216; 217, 218), so as to ensure that the shanks remain in good contact with the conductive blade (110) in the main opening (151). Geometry of the coupled conductive forks

[0045] The geometry of the coupled conductive forks (210, 220, 230) ensures precise alignment with the conductive blades (110, 120, 130) thanks to their planar structure and optimized spacing. Figure 5 shows a detailed schematic view of a planar conductive fork (211) inserted into a set of plated-through holes (313, 314) in the printed circuit board (300).

[0046] The conductive flat forks (211, 212) are cut from a conductive sheet, for example copper, or from a conductive laminated sheet as illustrated in [Fig. 6] with 3 sheets (810, 820, 830), to present two parallel legs (215, 216) forming a flat fork (211), extended by a head having two protrusions (255, 256) slightly longer than the thickness of the printed circuit board (300) and slightly narrower than the diameter of the holes (313, 314) in the printed circuit board (300). These legs (215, 216; 217, 218) are spaced at a distance calculated to allow the elastic insertion of a conductive blade (110, 120, 130). The jambs (215, 216) are curved inwards at their ends to facilitate the insertion of the conductive blades (110, 120, 130) while exerting uniform pressure, thus optimizing electrical contact. The conductive head formed at the base of the legs (215, 216) is configured to allow insertion into a pair of plated-through holes in the printed circuit board (300), ensuring reliable current transmission.

[0047] The two protrusions of the conductive head are inserted into two adjacent plated holes through the printed circuit board (300). Their slightly reduced geometry (compared to the diameter of the hole) facilitates the initial insertion.

[0048] A through-weld (400) covers the base of the conductive head with a bead (410) and extends into the contours of the hole (313, 314) to reinforce the mechanical and electrical connection. The solder forms a second bead (415) between two pairs of flat forks (211, 212) on the opposite side of the printed circuit board (300). This second bead (415) improves the mechanical stability of the connection, preventing any accidental movement or disengagement under mechanical or thermal stress. This method also ensures excellent heat dissipation and minimal electrical resistance.

[0049] The precision of the alignment between the fork (211) and the plated holes (313, 314) prevents any lateral play or torsion during assembly or operation.

[0050] The relative dimensions (thickness of the jambs, spacing between them, diameter of the hole) are carefully proportioned to comply with the constraints of the invention.

[0051] The edges of the conductive head are slightly chamfered, allowing for smooth insertion while avoiding damage to the metallized hole.

[0052] The materials of the fork (for example, copper or a silver-plated alloy) and of the solder are designed to offer maximum conductivity and increased resistance to corrosion.

[0053] The invention is distinguished from the prior art in particular by the fact that two flat forks (211, 212; 221, 222; 231, 232) are matched to form pairs of coupled conducting forks (210, 220, 230). The two coupled forks (211, 212; 221, 222; 231, 232) constitute a pair (210, 220, 230) of two parallel and flat forks, having a spacing (IJ) between the coupled forks of between 0.3 and 3 times the thickness of a shank.

[0054] The distance L3 separating the median line of the two of the heads (255, 256, 257, 258) of the forks corresponds approximately to the distance separating the two legs (215, 216).

[0055] The legs (215, 216; 217, 218) are slightly curved inwards at their ends to facilitate the guidance and capture of the conductive blade (110). The internal curvature creates uniform pressure on the inserted blade (110), optimizing the electrical connection.

[0056] The thickness of the legs (215, 216; 217, 218) is proportionate to provide sufficient elastic flex during insertion of the conductive blade (210) while preventing plastic deformation. The height of the legs (215, 216; 217, 218) is adjusted to allow for deep insertion and ensure a stable grip on the conductive blade.

[0057] At the end opposite the fork area, each leg is extended by a "conductive head". This head has a cross-section smaller than that of the plated-through holes in the printed circuit board, facilitating its insertion.

[0058] The conductive head has a square or rectangular cross-section to prevent rotation within the holes in the printed circuit board (300). The edges of the head are slightly chamfered to facilitate insertion and reduce mechanical wear on the printed circuit board (300). The holes (311, 312, 313, 314) in the printed circuit board (300) are round to improve mechanical retention and allow solder to flow between the round periphery of the plated-through holes and the rectangular cross-section of the heads (255, 256, 257, 258) of the forks.

[0059] The coupled forks may include ribs or grooves intended to limit excessive expansion of the legs under stress, thus ensuring a durable and stable connection.

[0060] By way of dimensional example, the dimensions of the forks are as follows: • Thickness of one jamb: 0.5 mm. • Spacing between the legs: 1.0 mm. • Total length of the fork: 10 mm. • Conductor head width: 1.2 mm (square). • Conductive head length: 2 mm.

[0061] This detailed geometry is designed to meet alignment, mechanical robustness and electrical performance requirements, while integrating into robotic industrial processes.

[0062] Figure 6 shows a cross-sectional view of a pair of conductive forks (210) inserted into a set of plated-through holes (212, 214) in the printed circuit board (300), in a plane perpendicular to that shown in the previous figure. As already explained, the forks are coupled to form pairs of conductive forks (210, 220, 230). The two protrusions of the conductive head are inserted into two adjacent plated-through holes in the printed circuit board (300), highlighting the spatial and structural relationships between the elements. This figure illustrates a specific view of the pairs of forks, their symmetrical geometry, and their role in connecting the components, complementing the aspects previously discussed.

[0063] Figure [Fig.6] shows a cross-sectional view of two coupled parallel flat forks, spaced at a specific distance of between 0.3 and 3 times the thickness of an individual fork.

[0064] Each fork consists of two symmetrical legs as previously described, extended by a conductive head whose protrusions are inserted into the metallized holes of the printed circuit (300).

[0065] These two forks form a "pair" which grasps, by elastic deformation, a conductive blade inserted in the gaps created by their legs.

[0066] The printed circuit board (300) has series of four adjacent plated holes, aligned vertically with the legs of the forks and transversely with the extensions of the paired conductive heads. These through holes allow for robust and stable attachment of the conductive head extensions.

[0067] Through-welds are visible around the heads of the forks, reinforcing the mechanical and electrical connection on the opposite side of the printed circuit board (300).

[0068] The proximity and precise alignment of the two forks in this configuration allow a firm and homogeneous grip on a single conductive blade by defining a quadrilateral for the insertion of a blade (110, 120, 130).

[0069] The symmetrical geometry of the coupled forks (210, 220, 230) ensures a uniform distribution of the pressure exerted by the legs on the blade, which improves the quality of the electrical connection and limits wear on the materials.

[0070] The internal guide lines of the plated holes help to perfectly align the conductive heads during insertion. This design reduces the risk of misalignment or damage to the printed circuit board (300).

[0071] The paired configuration prevents any rotation or twisting of the forks, ensuring increased mechanical stability even under thermal or vibratory stress.

[0072] The structure shown in [Fig.6] shows a high modularity, allowing this design to be adapted to conductive blades of different dimensions by adjusting the spacing of the forks or the size of the metallized holes.

[0073] This flexibility is essential for applications where high currents (up to 200 amps) or moderate voltages (12 to 72 volts) are required.

[0074] Additional details on materials:

[0075] The forks may be made of a conductive alloy covered with a silver-plated or similar coating, improving conductivity and corrosion resistance.

[0076] The through-welds include a reinforced base which partially penetrates the printed circuit board (300), increasing the durability of the connection.

[0077] Figure 6 elaborates on aspects of the interaction between the printed circuit board (300) and the pairs of conductive forks, with particular emphasis on:

[0078] The parallel pair configuration, essential for an efficient connection with a single conductive blade. Printed Circuit Board Soldering (300)

[0079] The base of the conductive head is designed to allow the weld to penetrate the plated hole. This geometry ensures an optimal mechanical and electrical connection. One variant includes a weld bead that partially covers the legs to reinforce the structure.

[0080] The legs and the conductive head can be coated with a conductive material, such as a silver-plated alloy, to improve conductivity and prevent corrosion. Guided Sleeves:

[0081] The conductive blades can be surrounded by overmolded sleeves (150, 160, 170) for mechanical and electrical protection. These sleeves (150, 160, 170) include guide pockets for precisely aligning the blades with the forks. These sleeves have internal guide zones that precisely align the blade with the shanks during insertion.

[0082] Reduction of the risks of misalignment and deformation during robotic assembly. • Improved mechanical robustness thanks to through welding and blade guidance. • Easy integration into industrial processes, minimizing human error Detailed view of the engine according to the invention

[0083] The motor is represented in its entirety by the figure [Fig.2], with the cylindrical protective casing (150) housing the stator and the rotor.

[0084] The conductive blades (110, 120, 130) terminating the stator windings are inserted into the conductive coupled forks (210, 220, 230) mounted on the printed circuit board (300). Their axial orientation, visible in this view, ensures efficient guidance and a secure electrical connection when the printed circuit board (300) is applied transversely, perpendicular to the axial direction, by means of an axial displacement.

[0085] The printed circuit board (300) is installed perpendicular to the axis of the motor. It includes several surface-mount electronic components (SMDs) responsible for controlling and regulating the motor. These components include capacitors used for current filtering and improving the electrical stability of the motor, resistors, processors, and other power circuits.

[0086] The plated holes (310, 320, 330), aligned with the conductive coupled forks, constitute connection points for the coupled forks conductive (210, 220, 230) and through-welding of the feet of the coupled conductive forks (210, 220, 230).

[0087] These conductive coupled forks (210, 220, 230) allow for an elastic connection of the conductive blades (110, 120, 130) with the metallic tracks of the printed circuit board (300). These conductive coupled forks (210, 220, 230) are provided with two flexible legs that hold the inserted conductive blades (110, 120, 130) under elastic tension.

[0088] The printed circuit board (300) is securely held by supports or spacers that ensure its position relative to the motor. This structure reduces vibrations and prevents misalignment during operation.

[0089] The solder joints are through-weld to securely fix the coupled forks to the printed circuit board (300) while ensuring a high-quality electrical connection.

[0090] Figure 3 provides a detailed partial cross-sectional view of the electric motor and highlights specific elements related to the assembly of the conductive blades, the coupled conductive forks, and the printed circuit board. It complements the descriptions in the preceding figures by elaborating on the mechanical and functional aspects not yet described.

[0091] Figure [Fig. 3] illustrates the axial insertion of the conductive blades (110, 120, 130) into the coupled forks (210, 220, 230). The elastic legs of the coupled forks apply uniform pressure to the blades, ensuring a reliable connection and minimizing electrical resistance. The conductive blades (110, 120, 130) are surrounded by an overmolded sleeve that guides the corresponding fork during insertion by precisely aligning the blades with the coupled forks to prevent any deviation during assembly. These sleeves also provide additional electrical insulation to protect against short circuits and improve the mechanical robustness of the assembly by limiting vibrations and unwanted movement.

[0092] The partial section [Fig.3] highlights the proximity and interaction between the internal components of the motor and the printed circuit board (300). The plated-through holes (310, 320, 330) on the printed circuit board (300) are well aligned with the heads of the coupled forks (210, 220, 230) to ensure optimal insertion and soldering.

[0093] Figure [Fig.3] shows the direct and compact connection between the stator and the printed circuit board (300). The coupled forks (210, 220, 230) play a critical role by acting as flexible but robust conductive bridges, suitable for high currents (50 to 200 amperes) and intermediate voltages (12 to 72 volts).

[0094] Figure 3 illustrates the mechanical and functional integration of the system, highlighting the technical solutions that ensure: • A stable electrical connection between the stator and the printed circuit board (300) via the coupled forks (210, 220, 230). • Mechanical and electrical protection thanks to overmolded sleeves. • Easier assembly and increased robustness thanks to welding through. Assembly Process

[0095] The forked connection means are inserted into the plated-through holes of the printed circuit board (300) from the lower surface, which faces the stator. Once inserted, they pass through the printed circuit board (300) to be soldered to the upper surface. The stator's conductive blades are inserted into the connector forks by an axial movement. The elastic flexibility of the forks ensures a secure grip without damaging the blades.

[0096] The solder joints sometimes pass through the printed circuit board (300) to form a bead between the flat coupled forks, thus reinforcing the assembly.

Claims

Demands

1. - Electric motor (100) comprising: - a stator supporting coils supplied by conductors terminated by conductive blades (110, 120, 130) extending in an axial direction - a printed circuit board (300) having plated-through holes (310, 320, 330), extending in a plane perpendicular to said axial direction - the connection between conductive blades and said printed circuit board being ensured by forked connection means (210, 220, 230) inserted into said printed circuit board (300) and plugged onto said conductive blades characterized in that: - said forked connection means (210, 220, 230) consists of a pair of parallel, planar, coupled forks spaced at a distance of between 0.3 and 3 times the thickness of a fork, each fork having two legs forming a fork for the insertion by elastic deformation of a conductive blade, extended at the opposite end by a conductive head with a cross-section smaller than the cross-section of said holes in the printed circuit board for insertion into the printed circuit board from its lower surface oriented towards said stator - each of said pairs of coupled forks being mounted on said printed circuit board by passing through two parallel plated holes, and by a solder joint on the face of the printed circuit board opposite said stator, and passing at least partially through said plated holes - said printed circuit board having sets of quarter-holes arranged in the projection of said conductive blades of said stator.

2. - Electric motor (100) according to claim 1 characterized in that that the solder passes through the printed circuit board (300) to cover a part of said protrusions of the coupled legs (210, 220, 230).

3. - Electric motor (100) according to the preceding claim characterized in that the weld passes through the printed circuit board (300) to form a bead between the coupled forks (210, 220, 230).

4. - Electric motor (100) according to claim 1 characterized in that said conductive head has two protrusions of rectangular cross-section (256; 257), and in that the holes of said printed circuit (300) have a round cross-section.

5. - Electric motor (100) according to claim 1 characterized in that said conductive blades (110, 120, 130) are surrounded by an overmolded sleeve (159, 160, 170).

6. - Electric motor (100) according to the preceding claim characterized in that said sleeves (110, 120, 130) have internal guiding zones for the four legs of a pair of coupled conductive forks.