Electric motor with improved assembly

Abstract

The present invention relates to an electric motor comprising a stator having a plurality of radial teeth, which are composed of a bundle of ferromagnetic laminates and are overmolded to form an overmolded stator support, wherein the stator support has notches between each tooth designed to receive wires of an electric coil, and at least a portion of the overmolded teeth are surrounded by an electric coil when the bundle of ferromagnetic laminates forming the electric coil is overmolded, and the stator support has a tubular casing at the front end of the teeth defining a cylindrical cavity for receiving a rotor, wherein the overmolded stator support is at least partially closed by a transverse disc partition having an axial sleeve for centering the shaft of the rotor, and the outer surface of the transverse disc partition opposite the cylindrical cavity of the rotor has means for mechanically fixing at least one of an electric element comprising conductive tracks for interconnecting wires of a coil, and / or an electronic substrate, and / or support studs for reversing winding wires.

Description

Technical Field

[0001] The present invention relates to the field of electric motors, and more particularly to electric fan motors.

[0002] One of the techniques used to manufacture such motors is to provide a ring-shaped plastic coil support and insert teeth consisting of a stack of ferromagnetic laminations magnetically connected by yokes into this support. These overmolded teeth are usually surrounded by winding wires, which are copper insulated with varnish. The wires of these coils are connected by metal tracks soldered to each coil wire in an appropriate topology. This type of motor has several drawbacks, such as the axial bulk resulting from coil connections, the number of parts assembled during manufacturing, and the complex assembly methods to ensure reliable, robust, and competitive industrial scaling.

Background Art

[0003] The prior art includes Patent Document 1, which relates to a stator for an electric motor, particularly a high-output low-voltage motor of the external armature type, comprising a stack of stator laminations having a plurality of stator grooves and stator teeth for accommodating stator windings, and an interconnection system for interconnecting the winding wires of the stator windings. The stator windings wound around the stator teeth through the stator grooves project beyond both end faces of the stack of stator laminations of the coil head. The interconnection system consists of winding contact elements and interconnection contact elements, and at least the interconnection contact elements are substantially located within a space bounded by the plane defined by the stator windings and the coil head.

[0004] Patent Document 2 relates to a trough-shaped stator support in which a stator base is arranged on the radially outer surface. This stator base has an inner yoke ring, from which stator teeth formed from the same portion as the yoke ring protrude radially outward. An insulating coil body, around which a coil is wound, is connected and locked to the stator teeth from the radially outer side, and an axially extending receiving pocket for a fragment ring deinsulation element is integrally formed on the radially outer side of the coil body.

[0005] Patent Document 3 describes an electric motor stator comprising a core and a covering overmolded on the core. The mold for overmolding the covering on the core comprises a first cavity defining portion and a second cavity defining portion, and a plurality of first and second pins extending at least generally to the portion opposite the cavity defining portion. The cavity is designed to receive the core. The first and second pins are designed to extend into the cavity when the mold is in a closed position to at least partially secure the core within the cavity. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] International Publication No. 2003081755(A1) [Patent Document 2] U.S. Patent Application Publication No. 2012098363 [Patent Document 3] U.S. Patent No. 10243434 [Overview of the Initiative]

[0007] (Disadvantages of prior art) The solution proposed in Patent Document 1 is complex on an industrial scale and involves positioning and inserting contact elements into a coil support, winding wire around these contact elements, cutting the wound wire between specific coils to wind new coils, and interconnecting the contact elements with interconnecting blades that cover these contact elements. This means that a large number of parts must be handled during the assembly stage, and bulkiness is created by the space occupied by these upright contact elements above the plane of the wound wire.

[0008] The solution proposed in Patent Document 2 does not allow for continuous winding of the same wire for all coils already in place. This method involves installing already wound coils, then setting up a peripheral interconnect assembly, then soldering two wires of each coil to this peripheral interconnect assembly, and then closing it with a sealing ring.

[0009] The solution proposed in Patent Document 3 relates to an external rotor motor. Such motors are unsatisfactory because external rotors have high inertia and generate a lot of noise. Furthermore, the solution proposed in this patent has the disadvantage that it is difficult to wind the stator coil wires around the stator body and interconnect them. Moreover, the connection between the winding wires and the printed circuit board is located within the same volume as the rotor. [Problems that the invention aims to solve]

[0010] The object of the present invention is to improve upon these drawbacks, and relates to an electric motor comprising a stator comprising a plurality of radial teeth comprising a bundle of ferromagnetic laminates and overmolded to form an overmolded stator support, wherein the stator support has notches between each tooth designed to receive wires of an electric coil, and at least a portion of the overmolded teeth are surrounded by an electric coil when the bundle of ferromagnetic laminates forming the electric coil is overmolded, and the stator support has a tubular casing at the front end of the teeth defining a cylindrical cavity for receiving a rotor, wherein the overmolded stator support is at least partially closed by a transverse disc partition having an axial sleeve for centering the shaft of the rotor, and the outer surface of the transverse disc partition opposite the cylindrical cavity of the rotor has means for mechanically fixing at least one of the following electric elements. - Conductive tracks for interconnecting coil wires. and / or - Electronic circuit boards and / or - Support studs for reversing the winding wire.

[0011] In particular, the present invention relates to an electric motor having some or all of the following features.

[0012] The stator support is composed of a single bundle of ferromagnetic laminates having multiple radial teeth, the overmolded stator support is surrounded by a ferromagnetic stator yoke, and the electrical coil is formed by wires wound around the overmolded teeth of the bundle of ferromagnetic laminates.

[0013] The axial centering sleeve is formed by a tubular neck having a closed bottom.

[0014] The axial centering sleeve is formed by a tubular neck having an open bottom.

[0015] The axial centering sleeve is suitable for receiving a guide bearing for the shaft of the rotor.

[0016] The axial centering sleeve includes a sliding bearing for guiding the shaft of the rotor.

[0017] The axial centering sleeve includes a passage through which the shaft of the rotor passes.

[0018] The transverse disk-shaped partition is connected to the tubular casing of the stator support by a plurality of deformable regions.

[0019] The deformable region takes the form of a link arm inclined with respect to the radius.

[0020] The connecting arm is connected to the tubular casing of the stator support in a region for centering the teeth.

[0021] The stator support has fixing means located between two consecutive notches.

[0022] The fixing means consists of a fixing eyelet located in the radial extension of the stator support.

[0023] The fixing means consists of an axial stud.

[0024] The tubular casing is characterized by axial weakening grooves between each tooth in order to allow elastic angular deflection of the tooth on either side of a radial reference plane.

[0025] The inner surface of the transverse disk-shaped partition closing the cylindrical rotor cavity is characterized by reinforcing ribs for preventing warping of the transverse disk-shaped partition.

[0026] The connecting arm forming the deformable region is an extension of the reinforcing rib.

Brief Description of the Drawings

[0027] The present invention will be better understood by reading the following description relating to non-limiting exemplary embodiments illustrated by the accompanying drawings. [Figure 1] This is an exploded view showing a partial cross-sectional view of a modified example of a motor according to the first modified example of the present invention. [Figure 2] This figure shows a disassembled 3 / 4 front view of a modified version of the first embodiment of the present invention. [Figure 3] This figure shows a more partially disassembled 3 / 4 rear view, according to a modification of the first embodiment of the present invention. [Figure 4] This figure shows a 3 / 4 oblique view of the top surface of the stator support before winding, according to a modification of the first embodiment of the present invention. [Figure 5] This is a 3 / 4 perspective top view of a stator support after winding, according to a modification of the first embodiment of the present invention. [Figure 6] This figure shows the bottom surface of the stator support before winding, according to a modification of the first embodiment of the present invention. [Figure 7] This is an exploded view showing a partial cross-sectional view of an exemplary embodiment of a motor according to a modification of the second embodiment of the present invention. [Figure 8] This figure shows the bottom surface of the stator support before winding, according to a modification of the second embodiment of the present invention. [Figure 9] This is a 3 / 4 perspective view of the stator support after winding and inserting the stator yoke according to a modification of the second embodiment of the present invention. [Figure 10] This figure shows the bottom surface of the stator support before winding, according to a modification of the second embodiment of the present invention. [Figure 11] This figure shows a cross-section according to a modified example of the second embodiment of the present invention. [Modes for carrying out the invention]

[0028] (General principles of the present invention) The present invention relates to a motor comprising a stator assembly (100) having overmolded teeth (120) surrounded by coils, forming a tubular casing (141) that defines a cylindrical cavity (250) on which a rotor (200) rotates.

[0029] The present invention relates to a stator assembly (100) configuration comprising a set of overmolded teeth (120) having coils wound around the overmolded teeth (120), and a ferromagnetic stator yoke (110), which is closed by a perforated transverse disc partition (151) and has the primary function of centering a rotor (200) relative to a stator (100), and the additional function of holding some of the electrical elements of the stator through reliefs in the form of projections (155) or cavities formed on one of the surfaces of the transverse disc partition (151), thus different from the prior art.

[0030] In this way, the stator block (100) forms a single plastic component overmolding the ferromagnetic teeth, creating a robust component that directly centers the rotor relative to the winding teeth, and securely connects the electrical elements that supply power to the coils, resisting vibration and other disturbances.

[0031] The shaft is centered by an axial sleeve (152), which may have an open or closed bottom. The shaft is guided inside this sleeve in a conventional manner, for example, by bearings or sliding bearings.

[0032] To avoid deformation of the stator component due to the plastic injection process, an optional solution is to provide a deformable peripheral region for the transverse disc-shaped partition (151) of the stator component in the annular region between the periphery of the transverse disc-shaped partition and the tubular casing (141), for example, by providing peripheral recesses alternating with radial beams, or inclined arms that allow the transverse disc-shaped partition to take its dimensions after overmolding, thereby providing a deformable peripheral region without damaging the disc-shaped component if it is excessively constrained by the tubular casing, or without deforming the tubular casing if the diameter of the disc-shaped partition decreases due to plastic shrinkage during cooling.

[0033] In another optional variant, the stator assembly is configured to allow angular deflection of the teeth in order to reduce the noise caused by detent torque when moving from one increment to the next.

[0034] This angular deflection is achieved, for example, by forming slots (175) around the transverse disc-shaped partition (151) and / or by locally weakening the overmolding through axial grooves (146) formed between teeth (120) within the tubular casing (141).

[0035] Each tooth (120) is formed by a stacked and overmolded laminated block that forms an insulator that will be wound after overmolding.

[0036] The teeth (120) are preferably overmolded and have their rear surfaces flush with the ferromagnetic stator yoke (110) surrounding the tubular casing, and each tooth has a notch (135) between it that allows the winding wire to pass through before the ferromagnetic stator yoke is fitted.

[0037] Optionally, the teeth can also have tubular crowns extending radially, in which case the ferromagnetic assembly is overmolded. In this case, the winding is braided by alternately passing wires up and down around the body formed by each overmolded tooth or through notches provided on the inner surface of the overmolded assembly.

[0038] Optionally, the tubular stator portion has a fixing means (157) on the tooth extension, preferably located between two consecutive notches (135). These fixing means (157) can take the form of a radial extension (145) with a fixing eyelet, or an axial stud, or any other shape that can ensure the following: - The stator assembly, or even the entire motor, may be hooked. -And in some variations, there is a stopper for the ferromagnetic stator yoke.

[0039] Some of the reliefs formed on the surface of the transverse disc partition (151) have support studs (650) for rerouting the winding wire, while other reliefs are in the form of ribs (158) that can lift specific sections of the winding wire to prevent them from coming into contact with conductive tracks (610, 620, 630) provided on the surface of the transverse disc partition (151) and causing a short circuit when the wire is accidentally stripped or peeled off, or they can also serve to position the conductive tracks (610, 620, 630). The reliefs may consist of pins (154) designed to hold the conductive tracks (610, 620, 630) by coupling onto the top of these pins (154). Finally, but still in a non-limiting manner, the reliefs may be cylindrical projections (155) with holes for forming means of securing an electronic card (400) electrically connected to a connection assembly (600).

[0040] (Detailed description of the first embodiment) The examples of embodiments described with reference to Figures 1 to 6 relate to a fan, particularly a "pancake" type electric motor used in a forced ventilation function, and more specifically to an electronically rectified multiphase motor having a drive control unit incorporated in the motor housing and coils exposed to airflow for optimal cooling.

[0041] The solution provided by the present invention is of particular interest to the structure of high-power, low-profile motors (over 1kW) used, for example, to cool components of fast-charging devices for electric vehicles, but can also be used for any type of ventilated drive motor or pump, which can use fluid flow to cool stator coils located in a space exposed to airflow.

[0042] Figure 1 shows an exploded view of the motor excluding the impeller. It consists of the following components: - Stator assembly (100), - Rotor (200), - It consists of a guide flange (190) and...

[0043] The stator assembly (100) comprises an overmolded stator support (150) having a substantially tubular portion with overmolded teeth (120), one of which is laterally closed by a transverse disc partition (151) having an axial sleeve (152) for centering and guiding the rotor (200).

[0044] The surface area of ​​this transverse disc-shaped partition (151) is greater than 50% of the surface area of ​​the internal cavity of the tubular casing (141). The solid portion directly connects the central shaft guiding and connection area to the tubular casing (141) without the need for additional parts fixed to the stator portion, thereby avoiding the risk of deformation and reducing tolerance and industrial scaling difficulties.

[0045] At the axial end opposite to this transverse disc-shaped partition (151), the overmolded stator support (150) is closed by a guide flange (190), which is preferably secured by laser welding or thermal welding.

[0046] The rotor (200) has a shaft (350) that is guided on one side by a transverse disc-shaped partition (151) and on the other side by a guide flange (190).

[0047] The stator support (150) is overmolded by injection molding of plastic material with a set of radial teeth (120) also formed by a bundle of laminates, and is coplanar with the outer circumference to make mechanical and magnetic contact with the peripheral stator yoke (110) surrounding the stator support (150). This overmolding forms a coil body (140) for winding that generates a magnetic field that interacts with the rotor (200).

[0048] These coil bodies (140) extend radially along the teeth from a tubular casing (141) whose inner surface coincides with the front surface of the teeth (120) to the radial peripheral or distal end of the teeth. Thus, the coil bodies form a thin casing along the teeth, designed to ensure good electrical insulation between the coil wire and the stack of ferromagnetic laminates forming the teeth. The coil bodies extend radially along the teeth (120) with minimal thickness to maximize space for the electric coil (130), while ensuring electrical insulation between the coil (130) and the stack of laminates of teeth (120). At the front end of the teeth, the tubular casing (141) extends axially to provide a forward support surface for the wire during winding. The axial extension of the tubular casing (141) protruding from the transverse disc partition (151) forms a forward annular extension (148).

[0049] The transverse disc-shaped partition (151) and the front annular extension (148) form an inner region (170) designed to receive the ends of the winding wire and ensure their electrical connection. For this purpose, the front annular extension (148) is provided with notches or slots to allow the winding wire to pass between the coil body (140) and the inner region (170), while ensuring axial and lateral guidance of the inner region. At the distal end of the teeth, the coil body (140) extends axially and tangentially over the desired coil range to provide a distal support region for the coil wire (130). The distal tangential extension of the coil body (140) is not continuous between the teeth (120) but extends over a peripheral angular sector (142), leaving a free angular sector (143) to facilitate the movement of the wire during winding.

[0050] In its inner portion, the tubular casing (141) defines a cylindrical cavity (250) for receiving a rotor (200) on the side of the transverse disc-shaped partition (151) opposite to the inner region (170). This cylindrical cavity (250) can be closed by a guide flange (190) on the opposite side of the transverse disc-shaped partition (151).

[0051] The axial sleeve (152) is traversed by a central shaft (350) designed to center and guide the rotor (200). The shaft (350) is connected to the rotor (200) and guided by bearings (230, 240) located within the axial sleeve (152) formed on the transverse disc partition (151) and within the housing (195) of the guide flange (190), respectively.

[0052] In the illustrated example, the bundle of laminates forming the teeth is manufactured as a single unit in the form of a tubular ring extended radially by the teeth. In the tubular casing (141), the overmolding is axially adjacent to the inner circumference of the tubular ring. However, those skilled in the art can also envision a variation in which the teeth are not joined by the bundle of laminates but by a plastic overmolding. The tubular ring is then formed by the ends of the teeth connected by an overmolded arched portion. It is also conceivable to cover the front ends of the teeth with a resin overmolding to protect the bundle of laminates of teeth, but this would increase the magnetic air gap and thus reduce mechanical performance.

[0053] (Detailed description of the transverse disc-type divider (151)) As shown in Figures 1 to 6, in addition to the aforementioned function of centering the rotor (200), the transverse disc-type partition (151) has the additional function of mechanically fixing the electrical elements of the stator, which can take the form of, in particular, a means for fixing single-winding wire reversal points, coil interconnection tracks, or means for fixing an electronic circuit board (400) for motor control by supplying power to the coils.

[0054] In the illustrated examples, particularly those shown in Figures 4 and 5 for the first embodiment, the upper surface of the transverse disc partition (151) is characterized by pins (154) that constitute plastic rivets for securing the inter-coil connecting tracks (610, 620, 630) by heat riveting, as will be detailed below. The conductive tracks (610, 620, 630) are secured before winding begins.

[0055] The transverse disc-shaped partition (151) is bounded around its periphery by a forward annular extension (148) that extends axially through the tubular casing (141) to form an inner region (170).

[0056] The front annular extension (148) is provided with a notch (149) in each coil (130), allowing the wound wire (131) to reach the inner region (170) from the coil body (140) and vice versa. As shown in Figures 1 to 6, the notch (149) can extend at an angle over a substantial portion of the coil body (140), and the two wires (131) forming the ends of the coil (130) pass through the front annular extension (148) within a single notch (149). The notch (149) then provides a region of maximum lateral clearance for the wires (131), but any other alternative configurations are possible, as shown in Figures 7 to 9, in which the wires are guided and laterally wedge within individual notches.

[0057] (Detailed explanation of coil interconnections) In a typical case, each coil (130) has a pair of wires (131) extending through a front annular extension (148) of a tubular casing (141).

[0058] In special cases, two or more coils are connected in series by continuous, unstripped wires, in which case the connecting wires between the coils do not need to return through the transverse disc-type partition (151), and thus a pair of radially extending wires corresponds to all coils in series. This is all the more true when the coils connected in series are adjacent, but those skilled in the art can also find ways to connect sets of non-adjacent coils in series using continuous wires while ensuring routing compatibility with other phase assemblies.

[0059] In a preferred embodiment, as described in this example, the teeth are wound by a single continuous wire that extends continuously through the coil and forms a loop inside the inner region (170), the wire surrounding interconnection support studs (650). These support studs (650) may consist of projections formed on the surface of the transverse disc partition (151) or extend from conductive tracks (610, 620, 630), allowing the wire to be rerouted to and electrically connected to the conductive tracks by a soldering operation that removes its insulating layer. During winding, the winding needle drives the winding wire (131) from the newly wound coil (130) through a notch (149) in the tubular casing (141) toward the surface of the transverse disc partition (151). The needle then reaches the support studs (650), bypasses the support studs, and then pulls the wire back toward the periphery to begin winding the next coil. It should be noted that all support studs (650) are distributed on a circle located between two conductive tracks (620, 630), and therefore, when a wire reaches the inner region (170) to connect to a conductive track (630) inscribed in the distribution circle of the support studs (650), the wire bypasses the metal support studs extending along the conductive track (630), ensuring the function of mechanical guidance and electrical contact in a single component. The metal support pins (650) are "V" shaped, and their arms are composed of curved portions of the metal track. The wire passes through the groove formed by this "V" shape and is reoriented to wrap around one of the arms. During electrical soldering work, the arms may be slightly folded back to improve electrical contact. The electrical connection means (660) for the other tracks take the same form as the metal support pins, and the wire simply passes through the groove formed by the two arms to bypass the appropriate support pin.

[0060] In the example described, the motor has three phases and brings the interconnection of coils to be grouped via a connection assembly (600) formed by three conductive tracks (610, 620, 630) cut from a single conductive sheet and folded to form support and electrical connection pins (650) or electrical connection means (660).

[0061] The conductive tracks (610, 620, 630) are piled on transverse disc partitions (151) before winding. They are secured to the transverse disc partitions (151) by bolting to pins (154) and angularly positioned by ribs (158), which also lift the winding wire to prevent it from coming into contact with the conductive tracks (610, 620, 630) and causing a short circuit if it is accidentally peeled or stripped. Note that notches (149) may also be used to lift the wire by providing axial support.

[0062] As particularly evident in Figure 5, the wire (131) alternates between the coil (130) and the connecting assembly (600) during automatic winding without breaking the wire.

[0063] To ensure optimal tension, the wire (131) is fixed to a starting point (640) formed by a flared shape, and the beginning of the wire is engaged and held by a wedge. It then passes radially through a notch (149) in the front annular extension (148), is wound onto the first coil body (140) formed by overmolding the first teeth (120), and then radially joins the transverse disc partition (151) by passing again through the notch (149) in the front annular extension (148). Inside the inner region (170), it joins the central part, possibly by engaging with a groove of an electrical connection means (660), bypasses a support stud (650), then crosses the front annular extension (148) through another notch (149), and then radially returns toward another coil (130) adjacent to the previous coil.

[0064] The wire (131) then wraps around the second tooth, then radially returns to the inner region (170), and again passes through the notch (149) of the front annular extension (148). Inside the inner region (170), it joins to the central portion, possibly engaging with the groove of the electrical connection means (660), bypasses the support stud (650), and then radially returns toward another coil (130) adjacent to the previous coil.

[0065] Electrical connections to the conductive tracks (610, 620, 630) can be made before, after, or simultaneously with the bypassing of the support stud (650).

[0066] In most cases, the wire (131) passes through the front annular extension (148) before and after each coil (130). However, if some coils (130) are connected in series, whether continuous or not, the wire (131) passes through the front annular extension (148) only to ensure a connection between the coil and the tracks (610, 620, 630) rather than a direct connection between the two coils (130), in order to reduce the number of passages and therefore the number of electrical soldering tasks.

[0067] In an advantageous configuration, the coil body (140) is ribbed to guide the wire and facilitate winding, which is particularly useful when winding wires with a large cross-section and high rigidity.

[0068] (Underside of the transverse disc-type partition (151)) As shown in Figure 6 for the first embodiment and in Figure 10 for the second embodiment, the lower surface of the transverse disc-shaped partition (151) located within the cylindrical cavity (250) housing the rotor (200) is characterized by reinforcing ribs (171).

[0069] These reinforcing ribs (171) extend across the front and / or rear surfaces of the transverse disc partition (151), reinforcing the transverse disc partition (151) and avoiding the risk of buckling due to torsional forces applied to the axial sleeve (152), for example, by the rotor shaft. These reinforcing ribs (171) may extend radially or have a shape adapted to prevent warping of the transverse disc partition (151).

[0070] The presence of these reinforcing ribs (171) can also help improve the movement of plastic material from one injection point to the entire volume of the part.

[0071] (Compensation for overmolding shrinkage) The stator assembly (100) is formed by plastic injection in a mold for overmolding the ferromagnetic teeth (100). The transverse dimensions of the transverse disc partition (151) cause shrinkage during crystallization and cooling of the part after overmolding, which, due to deformation and expansion of the tubular casing (141), may result in deformation of the overmolded stator support (150) between one open end and the other end closed by the transverse disc partition (151) and subjected to a centripetal force causing a slight taper. This taper alters the shape of the overmolded stator support (150), which may result in the front surfaces of the teeth no longer making optimal contact with the ferromagnetic stator yoke (110), and / or reducing the consistency of the magnetic air gap between the teeth and the rotor, or causing breakage that may lead to guiding or sealing failures.

[0072] To compensate for this contraction, the present invention proposes providing deformable regions (159) around the transverse disc-shaped partition (151) at the connection point with the tubular casing (141). These deformable regions (159) may arise from an annular alignment of slots (175), which are preferably located between two consecutive teeth (120) and alternate with arms angularly centered on the teeth (120). These deformable regions (159) may also consist of oblique arms arranged at a constant angular pitch to allow slight angular displacement of the central region relative to the tubular casing (141) when the transverse disc-shaped partition retracts. These oblique arms connect the region of the tubular casing (141) that centers the teeth (120) to a point angularly offset 10 to 40° from the periphery of the central region of the transverse disc-shaped partition (151). The deformable regions (159) preferably extend in line with the reinforcing ribs (171). In practice, the deformable region must be able to absorb the contraction deformation of the transverse disc-shaped partition (151), while the reinforcing rib (171) must prevent out-of-plane deformation of the transverse disc-shaped partition (151). Therefore, the shape is adapted to achieve both of these functions in a single part. For example, a radially extending rectangular beam can have good deformability in compression or tangential bending while resisting axial bending.

[0073] (Teeth that can be deflected) The alternating arrangement of openings (175) and deformable regions (159) around the periphery of the transverse disc-shaped partition (151) also creates weakened regions between the teeth (120), allowing for slight angular deflection of the teeth (120) through the elastic deformation of the overmolding. This weakening can also be achieved or enhanced by axial grooves (146) formed on the outer circumference of the tubular casing (141) at the center of the notch (135). This angular play, surprisingly, has the effect of preventing lateral forces, i.e., noise sources, arising from the periodic interaction between the magnet and the teeth, from being transmitted to the stator yoke (110).

[0074] (Hanging point) The stator assembly (100) is attached to the support or housing via extensions (145) of an overmolded stator support (150). These extensions (145) are preferably located along a radius passing through the center of the teeth (120) within an angular region defined by the peripheral angular sector (142). In contrast, the extensions are not located within the free angular sector (143) between two consecutive teeth. Nevertheless, the extensions can be located within the radius between the coiled portion of the teeth and the transverse disc partition (151), or on the outer circumference of the teeth (120), for example, above the stator yoke (110). This configuration avoids cluttering the intertooth space, i.e., the free angular sector (143), and thus facilitates the winding process. This also allows for better absorption of the forces introduced to the ferromagnetic teeth (120) by the rotor. In a non-limiting manner, fastening to a support is achieved by fastening means (157) using plastic rivets or heat-screw pins that extend axially through the extension (145). The extension (145) may also extend radially in the form of a lug through which an eyelet passes, or may feature a screw hole that acts as fastening means (157).

[0075] (Second exemplary embodiment) This second example is a modified embodiment that differs from the previous example in that the transverse disc-shaped partition (151) has a sealed inner region (170). Other features described above generally apply to this second embodiment, and modifications are described in the following paragraphs. This modified embodiment is shown in Figures 7 to 11.

[0076] To ensure a seal in the inner region (170), the transverse disc partition (151) has two concentric rings (161, 162) that form a forward annular partition (160) located on the inner circumference of the deformable region (159), with an annular groove (163) defined between them. Each of the rings (161, 162) is recessed by radial slots (164, 165) to allow the wires (131) of the coil (130) to pass radially and to guide the wires when winding the stator support (150). The upper part of the peripheral ring (162) has a fixed recess (166) for engaging with a hook for positioning and hooking a deformable recessed toroidal portion (180) made of, for example, elastomer.

[0077] The toroidal portion (180) has a lower section formed by two coaxial lips (181, 182) that straddle the peripheral ring (162), the lip (182) fitting into an annular groove (163), and the toroidal portion has a recessed upper section through which the radial wires of the coil (130) pass locally, the width of which the recessed slot is smaller than the cross section of the winding wire (131) to ensure tight clamping of the wires.

[0078] The toroidal portion (180) has cavities on both sides of each recessed slot, which open onto adjacent slots to allow for filling with adhesive or resin to provide a seal after the winding wire (131) is inserted.

[0079] These recessed slots coincide with the sidewalls of slots (165) in the peripheral ring (162).

[0080] The bottoms of the slots (165) of the peripheral ring (162) each have projections the same width as the cavity, forming supports for the winding wire (131), preventing the winding wire from causing shearing of the bottom of the toroidal section (180) during winding and preventing potential loss of seal of the front annular partition (160).

[0081] When all wires are in place, the inner region (170) is fabricated, for example, by depositing adhesive or silicone, and is completely sealed by an additional seal (800) positioned between the periphery of the front annular partition (160) and the transverse section (300). The annular configuration of the toroidal section (180) means that the seal (800) can be deposited across its entire upper surface in a single continuous dosing, ensuring a complete seal while limiting manufacturing costs.

[0082] The transverse portion (300) has an annular projection (320) having a shape complementary to the shape of the front annular partition (160), or a toroidal portion (180) covering it, providing a sealed peripheral barrier for the inner region (170).

[0083] While this is a favorable example, it is understood that other solutions for sealing the wire (131) passage are also possible. For example, the annular groove (163) between the rings (161, 162) can be filled with an adhesive or silicone deposit that is complementary to the gap and, thanks to its shape located on the transverse component, can be pushed into the slot (164, 165) by a piston effect during assembly with the transverse component (300). However, this second solution is more costly as it requires a much larger deposit of adhesive, a material that has a reputation for being expensive. Alternatively, a resin or silicone ring can be deposited on the peeling area of ​​the wire (131), or the peripheral ring cannot be positioned above the surface of the stator support and can be a forward annular partition formed on the underside of the transverse (300).

[0084] The upper part of the cross section (300) has a housing for an electronic circuit board (800), which is closed by a cover 300 (500) made of, for example, metal.

[0085] As shown in Figure 9, the stator yoke (110) is inserted axially, so that the outer surface of the teeth (120) comes into mechanical and magnetic contact with the inner surface of the stator yoke (110) to ensure magnetic flux closure. The stator yoke (110) is then held in place by the flexible extension (156).

[0086] In the direction opposite to the direction in which the flexible extension (156) extends, part or all of the extension (145) has fixing means (157) that securely connects to the transverse portion (300) by heat crimping.

[0087] The winding method differs in several respects. Firstly, the wire must pass through the rings (161, 162) via the slots (164, 165) to reach the inner region (170) which includes the conductive tracks (610, 620, 630). This embodiment also differs in that the support studs (650) are all bent extensions of the conductive tracks (610, 620, 630).

[0088] Each support stud (650) is associated with an electrical connection means (660) in the form of a deformable lug, which, after the wire (131) has passed through, folds back relative to the wire (131) surrounding the support stud (650) to provide a soldering point where the insulating coating of the wire is locally removed. The support studs (650) and electrical connection means (660) are formed by local deformation of metal tracks (610, 620, 630).

[0089] For example, as shown in Figure 11, the shaft (350) can alternatively be firmly connected to a transverse disc partition (151), and the rotor rotates around the shaft (350) via bearings (230, 240) integrated into the rotor housing (200). The central shaft is fixedly mounted to the guide nose (330) of the transverse section (300), which is inserted into the axial sleeve (152) of the transverse disc partition (151). In this case, the transverse disc partition (151) centers the rotor (200) relative to the stator.

Claims

1. The stator (100) comprises a bundle of ferromagnetic laminates, which is overmolded to form an overmolded stator support (150) having a plurality of radial teeth (120), the stator support (150) having notches (135) between each tooth (120) designed to receive wires (131) of an electric coil (130), at least a portion of the overmolded teeth (120) being surrounded by the electric coil (130) when the bundle of ferromagnetic laminates forming them is overmolded, and the stator support (150) has a tubular casing (141) defining a cylindrical cavity (250) for receiving a rotor (200) at the front end of the teeth. The overmolded stator support (150) is at least partially enclosed by a transverse disc partition (151) having an axial sleeve (152) for centering the shaft (350) of the rotor (200), and the outer surface of the transverse disc partition (151) opposite the cylindrical cavity (250) of the rotor (200) is for the following electrical elements, namely, - Conductive tracks (610, 620, 630) for interconnecting the wires of the coil, and / or - The electronic substrate (400), and / or - The support stud (650) for reversing the winding wire, An electric motor having means for mechanically fixing at least one of the following.

2. The electric motor according to claim 1, characterized in that the stator support (150) consists of a single bundle of ferromagnetic laminates having a plurality of radial teeth (120), the overmolded stator support (150) is surrounded by a ferromagnetic stator yoke (110), and the electric coil (130) is formed by wires (131) wound around the overmolded teeth (120) of the single bundle of ferromagnetic laminates.

3. The electric motor according to claim 1, characterized in that the axial centering sleeve (152) is formed by a tubular neck having a closed bottom.

4. The electric motor according to claim 1, characterized in that the axial centering sleeve (152) is formed by a tubular neck having an open bottom.

5. The electric motor according to any one of claims 1 to 3, characterized in that the axial centering sleeve (152) is suitable for receiving a bearing (230) for guiding the shaft (350) of the rotor (200).

6. The electric motor according to any one of claims 1 to 3, characterized in that the axial centering sleeve (152) is provided with a sliding bearing for guiding the shaft (350) of the rotor (200).

7. The electric motor according to any one of claims 1 to 3, characterized in that the axial centering sleeve (152) has a passage through which the shaft (350) of the rotor (200) passes.

8. The electric motor according to claim 1, characterized in that the transverse disc-shaped partition (151) is connected to the tubular casing (141) of the stator support (150) by a plurality of deformable regions (159).

9. The electric motor according to any one of claims 1 to 8, characterized in that the deformable region (159) is in the form of a connecting arm inclined with respect to the radius.

10. The electric motor according to claim 8, characterized in that the connecting arm is connected to the tubular casing (141) of the stator support (150) in the region where the teeth are centered.

11. The electric motor according to claim 1, characterized in that the stator support (150) has a fixing means (157) located between two consecutive notches (135).

12. The electric motor according to any one of claims 1 to 11, characterized in that the fixing means (157) consists of a fixing eyelet located on the radial extension (145) of the stator support (150).

13. The electric motor according to any one of claims 1 to 12, characterized in that the fixing means (157) consists of an axial stud.

14. The electric motor according to claim 1, characterized in that the tubular casing (141) has axial weakening grooves (146) between each tooth (120), and allows elastic angular deflection of the teeth on either side of the radial reference plane.

15. The electric motor according to claim 1, characterized in that the inner surface of the transverse disc-shaped partition (151) that closes the cylindrical cavity (250) of the rotor (200) has reinforcing ribs (171) to prevent warping of the transverse disc-shaped partition (151).

16. The electric motor according to any one of claims 1 to 15 and claim 8, characterized in that the connecting arm constituting the deformable region (159) is an extension of the reinforcing rib (171).

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