Powertrain component assembly

Abstract

The present invention relates to an assembly of powertrain components for a motor vehicle, comprising an axial flux electromachine including a rotor (110), a stator, and a first housing (130) to which the stator is fixed, and a second housing (230). According to the present invention, the assembly comprises at least one elastically deformable means (301, 302) sandwiched between the first and second housings.

Description

Technical Field

[0001] The present invention generally relates to the field of electromechanics.

[0002] More specifically, the present invention relates to the assembly of power train components.

[0003] The present invention is particularly suitable for use in the manufacture of power trains for electric or hybrid motor vehicles (passenger cars, trucks, buses, etc.).

Background Art

[0004] Axial flux electromechanics generally comprise at least one stator and one rotor, together with a magnetic air gap separating the two. The rotor holds a series of large permanent magnets, while on the other hand, a series of coils attached to teeth are held in the stator. When current is supplied to the coils, the rotor, which is rigidly connected to the output shaft of the electromechanics, receives the torque generated by the magnetic field (the generated magnetic flux becomes the axial flux for the axial flux electromechanics).

[0005] Conventionally, the teeth are fixed to a housing that surrounds the stator and rotor. To limit the axial size of the electromechanics, the thickness of the housing below the teeth is maintained at a minimum. This thickness is often further reduced because the housing includes an internal flow path for cooling the coils within its thickness.

[0006] When the electromechanics is operating, the coils and teeth are subject not only to mainly radial and axial forces but also to tangential forces. These are subject to electromagnetic forces resulting from the rotating magnetic field and the attraction of the rotor, as well as mechanical forces generated by the rotation of the shaft driven by the rotor. These mechanical forces are mainly transmitted through the bearings between the housing and the rotor. These may arise from misalignment of the shaft or rotor, eccentricity of the rotor, or the spline connection between the rotor and the shaft that transmits drive from the rotor to the shaft.

[0007] All these forces generate vibrations within the electromachine, causing deformation of the housing in particular, and resulting in movement of the housing and teeth. This becomes noise in the electromachine. Furthermore, the movement of the teeth causes fluctuations in the air gap, which significantly affects the performance of the electromachine. [Overview of the project]

[0008] In view of the above, the present invention proposes an assembly of powertrain components for a motor vehicle. - An axial magnetic flux electromachine comprising a rotor, a stator, and a first housing to which the stator is mounted, - The second enclosure, Equipped with, The set of elements described above comprises at least one elastically deformable means sandwiched between the first housing and the second housing.

[0009] Therefore, according to the present invention, the housing of an electromechanical device is supported by elastically deformable means relative to the rest of the powertrain. Thus, the housing of the electromechanical device exhibits increased rigidity in the area of ​​the elastically deformable means, which acts as a restorative member against movement of the housing. In other words, a lightweight, compact, and inexpensive elastically deformable means restricts the movement of the electromechanical device housing by coupling it to a second housing.

[0010] Therefore, the casing of an electrical machine is less susceptible to deformation during operation.

[0011] As a result, vibrations are absorbed, allowing the electromachine to operate with reduced noise. Furthermore, the air gap remains stable because its fluctuations during operation are limited. This stability allows designers to reduce the nominal air gap, thereby increasing the power output of the electromachine.

[0012] Other advantageous effects and non-limiting features of the assembly according to the present invention, when interpreted individually or in any technically feasible combination, include: - The element assembly comprises a shaft rotatably coupled to the rotor, the first housing comprises a central edge facing the shaft, and the elastically deformable means is positioned in contact with the central edge. - The second housing includes an extension designed to fit within the central edge with minimal clearance, and an elastically deformable means is interposed between the extension of the second housing and the central edge of the first housing. - The set of elements comprises a shaft rotatably coupled to the rotor about a rotation axis, and an elastically deformable means is interposed between a surface of a first housing substantially perpendicular to the rotation axis and a surface of a second housing substantially perpendicular to the rotation axis. -A mechanical connection is provided between the first housing and the rotor, or between the second housing and a shaft rotatably coupled to the rotor, and an elastically deformable means is positioned opposite the bearing, -The elastically deformable means is annular, -The elastically deformable means consists of an elastomer, -The elastically deformable means is compressed when the electromachine is stopped. - The element assembly further comprises a powertrain element housed in a second housing, the powertrain element being one of a transmission, a reduction gear, or other electromechanical device. [Brief explanation of the drawing]

[0013] [Figure 1] This is a schematic cross-sectional view of an assembly of powertrain components according to the present invention. [Figure 2] This is a detailed enlarged view of area II in Figure 1. [Modes for carrying out the invention]

[0014] The following description, given as a non-limiting example with reference to the attached drawings, clarifies what constitutes the invention and how it becomes implementable.

[0015] Figure 1 shows an assembly (1) of a powertrain component according to the present invention. In this embodiment, the assembly (1) is fitted into an electric or hybrid motor vehicle.

[0016] In the embodiments described, the powertrain comprises two separate housings that house different components, namely, an electromechanical unit (left side in Figure 1) and a reduction gear (200), a transmission, or other electromechanical unit (right side in Figure 1).

[0017] As shown in Figure 1, therefore, assembly (1) is - An axial magnetic flux electromachine 100 comprising a rotor 110, at least one stator 120, and a first housing 130, - The second enclosure 230, -At least one elastically deformable means 301, 302, It is equipped with.

[0018] Conventionally, the rotor (110) comprises a body (111) which may have a star shape with arms extending radially from a central hub around a rotation axis A1 (Figure 1). The axial direction here corresponds to the direction of the rotation axis A1, while the radial direction corresponds to the direction perpendicular to the axis. The arms define slots that open radially outward, each receiving a magnetic pole element (112). The magnetic pole elements (112) can be held in place by a retaining sleeve (113). Thus, the rotor (110) as a whole has a disc shape centered on the rotation axis A1.

[0019] Assembly (1) also includes a shaft (400) rotatably coupled to the rotor (110) so as to be driven by its rotation, particularly around axis A1. The shaft (400) transmits the rotational motion of the rotor to the wheels of the vehicle. The shaft (400) is mechanically coupled to the rotor (110) by spline connections.

[0020] As shown in FIG. 1, the rotor body (111) includes a tubular shaft portion (114) centered on the axis A1. One end of the shaft (400) is fitted into the shaft portion (114) of the rotor body (111) of the rotor (110). Each of the shaft (400) and the shaft portion (114) has ribs (115, 401) that extend parallel to the rotation axis A1 to form a spline connection, as shown in FIG. 2 (which is an enlarged view of the central part of the assembly). Therefore, the rib (115) of the shaft portion (114) cooperates with the rib (401) of the shaft (400) to transmit the rotation of the rotor (110).

[0021] As shown in FIG. 1, the axial flux electrical machine (100) includes two stators (120) positioned on both sides of the rotor (110) here. Each stator (120) has a flat annular shape, and teeth (121) around which conductive windings (122) are wound are provided on the surface facing the rotor. When current is supplied to the winding (122), a rotating magnetic field that drives the magnetic pole elements (112) is generated, thereby rotating the rotor (110) about the rotation axis A1.

[0022] The following description focuses on the stator (120) on the side of the shaft (400) (the right side of the rotor 110 in FIG. 1), which is hereinafter referred to as the "stator (120)". The teeth (121) and windings (122) described below are those of this stator (120).

[0023] In the electrical machine (100), the distance between each tooth (121) facing the magnetic pole element (112) is called the magnetic air gap. Preferably, the air gap is short enough to ensure a high attraction force between the coil (122) and the magnetic pole element (112).

[0024] The first housing (130) surrounds the stator (120) and the rotor (110). The first housing (130) serves as a protective enclosure in the sense that it is designed to protect the stator (120) and the rotor (110).

[0025] The first housing (130) also supports the stator (120). The stator (120), more specifically its teeth (121), is actually fixed to the first housing (130). Thus, the housing has sufficient rigidity to maintain the position of the teeth. The first housing (130) can be made from a metal such as aluminum, die-cast aluminum alloy (AlSi9Cu3), steel, or cast iron.

[0026] As shown in Figure 1, the first housing (130) comprises several assembled parts, one of which is adjacent to the second housing (230). This part has a substantially planar wall perpendicular to the rotation axis A1, and is hereinafter referred to as the lateral wall (133). This lateral wall (133) is separated by a peripheral wall (132) that surrounds the stator (120).

[0027] This portion has a central opening defined by the central edge (131). The central edge (131) of the first housing (130) extends cylindrically around axis A1, as shown in Figure 1.

[0028] The teeth (121) of the stator (120) are fixed to the inner surface (134) of the lateral wall (133) which is substantially perpendicular to the axis of rotation A1. The terms “substantially perpendicular” or “substantially perpendicular” to the axis of rotation A1 are understood here to mean a direction or surface that makes an angle of 89 to 91 degrees with respect to the axis of rotation A1. For example, a maximum deviation of 0.12° of the axis of rotation may be given to the dimensional chain. The lateral wall (133) of the first housing (130) has, for example, a thickness of 7 mm, i.e., an axial dimension.

[0029] The second housing (230) has a diameter similar to that of the first housing (130) over at least a portion of its axial length, i.e., a dimension perpendicular to the axis of rotation A1. The second housing (230) is made of the same material as the first housing (130), for example.

[0030] The second housing (230) is structurally connected to the first housing (130), particularly at the peripheral wall (132) of the first housing (130). The first housing (130) and the second housing (230) are fastened to each other, for example, by screws.

[0031] As shown in Figure 2, the second housing (230) includes a planar wall (233) facing the first housing (130) which has an opening through which the shaft (400) passes. The planar wall (233) holds a tubular extension (231) on the side facing the first housing, which is designed to fit with assembly clearance into the opening defined by the central edge (131) of the first housing (130). The clearance between the extension (231) and the central edge (131) is, for example, 20 μm to 60 μm. The extension (231), also called the centering bearing surface, makes it possible to center the first housing (130) relative to the second housing (230) during powertrain assembly. This ensures, in particular, that the ribs (115) of the rotor (110) are centered and therefore aligned with the ribs (401) of the shaft (400).

[0032] Assembly (1) comprises a first bearing (501) positioned between the first housing (130) and the rotor (110), and a second bearing (502) positioned between the second housing (230) and the shaft (400). The first bearing (501) provides a mechanical connection between the first housing (130) and the rotor (110), more specifically between the shaft portion (114) of the rotor (110) and the first housing (130). The second bearing (502) provides a mechanical connection between the shaft (400) and the second housing (230). Thus, these mechanical connections provide rotational guides for the shaft (400) and the shaft portion (114).

[0033] Therefore, as shown in Figure 1, assembly (1) is -A first elastically deformable means 301, - A second elastically deformable means 302, It is equipped with.

[0034] Each elastically deformable means (301, 302) is positioned between the first housing (130) and the second housing (230), i.e., interposed between them. More specifically, each elastically deformable means (301, 302) is sandwiched between the first housing (130) and the second housing (230). In the illustrated embodiment, each elastically deformable means (301, 302) is in direct contact with both the first housing (130) and the second housing (230).

[0035] Each elastically deformable means (301, 302) is positioned to counteract the movement of the first housing (130) relative to the second housing (230). Thus, each elastically deformable means (301, 302) acts as a damper in the sense that it dampens the displacement of the first housing (130), and supports the second housing (230).

[0036] Each elastically deformable means (301, 302) is "elastically deformable" in the sense that it undergoes elastic (and not plastic) deformation when the first housing (130) moves relative to the second housing (230) during the normal operation of the powertrain.

[0037] Preferably, each elastically deformable means (301, 302) is compressed when the electromachine (100) is stopped. This means that each elastically deformable means (301, 302) is clamped between the first housing (130) and the second housing (230).

[0038] Advantageously, the elastically deformable means (301, 302) are located near the shaft (400) (and therefore the bearings (501, 502)), that is, in this case, within or near the central opening of the first housing (130). This means, in particular, that the elastically deformable means (301, 302) are closer to the central edge (131) of the first housing (130) than to the peripheral wall (132). In practice, the movement of the first housing (130) relative to the second housing (230) consists mainly of deformation of the first housing (130) in the region of its central opening. This is because the peripheral wall (132) of the first housing (130) is fixed here to the second housing (230) by screws. Therefore, by positioning the elastically deformable means (301, 302) near the shaft (400), it is possible to restrict the movement of the first housing (130) to the region where such movement is potentially maximum.

[0039] As shown in Figure 2, the first elastically deformable means (301) is positioned between the central edge (131) of the first housing (130) and the outer surface of the extension (231) of the second housing (230). Thus, the first elastically deformable means (301) is positioned in opposition to the radial movement of the first housing (130) (i.e., movement perpendicular to the axis of rotation A1), particularly toward the axis of rotation A1. In the illustrated embodiment, the first elastically deformable means (301) is positioned opposite the second bearing (502) to the extension (231) of the second housing (230). Thus, the first elastically deformable means (301) is positioned opposite the first bearing (501).

[0040] In the illustrated embodiment, the first elastically deformable means (301) is annular and extends around the shaft (400). It has, for example, a diameter of 64 mm.

[0041] As shown in Figure 2, the first elastically deformable means (301) is positioned on a shoulder (232) provided at the free end of the extension (231) of the second housing (230). The first elastically deformable means (301) has, for example, a substantially rectangular cross-section in a plane containing the axis of rotation A1. The stiffness of the first elastically deformable means (301) depends in particular on the dimensions of this cross-section. The stiffness is selected, for example, to filter out certain vibration frequencies.

[0042] Advantageously, the position and annular shape of the first elastically deformable means (301) enable effective centering of the second housing (230) relative to the first housing (130). In other words, the first elastically deformable means (301) improves the coaxiality of the extension (231) of the second housing (230) and the central edge (131) of the first housing (130) with respect to the rotation axis A1. Preferably, the extension (231) of the second housing (230) contacts the first elastically deformable means (301) without contacting the central edge (131) of the first housing (130). Notably, this centering improves the positional alignment of the rotor (110) rib (115) with respect to the shaft (400) rib (401), thereby reducing the stress on the first housing (130) when the rotor (110) rotates. Therefore, in addition to reducing the displacement of the first housing (130) by absorbing vibrations, the first elastically deformable means (301) also helps to limit the occurrence of such displacement.

[0043] As shown in Figure 2, the second elastically deformable means (302) is positioned toward the second housing (230) at one end of the central edge (131). More specifically, the second elastically deformable means (302) is interposed between the first housing (130) around its central opening and the planar wall (233) of the second housing around the extension (231) (Figure 2). The second elastically deformable means (302) is positioned in particular toward the second housing (230) to counteract the axial movement of the first housing (130), i.e., movement along the axis of rotation A1. In the illustrated embodiment, the second elastically deformable means (302) is positioned opposite the first bearing (501) with respect to the lateral wall (133). The second elastically deformable means (302) is also positioned opposite the second bearing (502) with respect to the planar wall (233). Therefore, the second elastically deformable means (302) is located at the same radial height as the first bearing (501) and the second bearing (502). Furthermore, it has a diameter similar to that of these bearings. In the example in Figure 1, it is located, for example, less than 10 mm from the first bearing (501) and the second bearing (502).

[0044] The second elastically deformable means (302) is sandwiched between two planes substantially perpendicular to the axis of rotation A1, i.e., between one plane of the first housing (130) and the other plane of the second housing (230). In the illustrated embodiment, the second elastically deformable means (302) is substantially flat and extends in a plane substantially perpendicular to the axis of rotation A1.

[0045] The second elastically deformable means (302) is, for example, annular. The stiffness (and therefore cross-section) of the second elastically deformable means (302) can also be selected to filter out certain vibration frequencies.

[0046] In the illustrated embodiment, the second elastically deformable means (302) is integrally formed and extends around the entire circumference of the rotation axis A1. In an alternative embodiment, the assembly may comprise a plurality of second elastically deformable means independently distributed around the shaft between the first and second housings, each of which may have the shape of a rectangular parallelepiped.

[0047] Advantageously, the second elastically deformable means (302) effectively limits the displacement of the first housing (130) along the rotation axis A1 and, consequently, the variation in the air gap. This results in more stable performance of the electromechanical unit (100) and allows for the assumption of a smaller air gap during the design phase.

[0048] Each elastically deformable means (301, 302) is made of, for example, an elastomer. Advantageously, each elastically deformable means (301, 302), in combination with the annular shape, also improves the sealing of the joint between the first housing (130) and the second housing (230) at the level of the shaft (400), thereby protecting the bearings (501, 502) from the ingress of possible dust.

[0049] Preferably, the stiffness of each elastically deformable means (301, 302) is selected to filter out a specific vibration frequency of the first housing (130), i.e., the frequency of the maximum amplitude.

[0050] The present invention is not limited in any aspect to the embodiments described and illustrated, and those skilled in the art should be able to understand how any modification thereof may be constructed.

[0051] Therefore, the assembly may comprise only the first elastically deformable means, or only the second elastically deformable means.

[0052] In other embodiments, the assembly may comprise a single elastically deformable means that performs the functions of both the first and second elastically deformable means. Such an elastically deformable means may have, for example, an L-shaped cross-section, i.e., a ring shape extending both axially and radially. It may be positioned, for example, at the central edge of the first housing and opposite to the extension and bottom surface of the second housing.

[0053] The elastically deformable means may also be fixed to the housing, for example, by adhesive, and they can operate in both compression and tension.

Claims

1. An assembly of powertrain components for a motor vehicle (1), An axial magnetic flux electromachine comprising a rotor (110), a stator (120), and a first housing (130) to which the stator (120) is fixed, The second enclosure (230), Equipped with, An assembly (1) comprising at least one elastically deformable means (301, 302) sandwiched between the first housing (130) and the second housing (230).

2. The assembly (1) according to claim 1, comprising a shaft (400) rotatably coupled to the rotor (110), the first housing (130) having a central edge (131) facing the shaft (400), and the elastically deformable means (301, 302) being arranged in contact with the central edge (131).

3. The assembly (1) according to claim 2, wherein the second housing (230) comprises an extension (231) configured to fit within the central edge (131) with minimal clearance, and the elastically deformable means (301) is interposed between the extension (231) of the second housing (230) and the central edge (131) of the first housing (130).

4. The assembly (1) according to any one of claims 1 to 3, comprising a shaft (400) rotatably coupled to the rotor (110) about a rotation axis (A1), wherein the elastically deformable means (302) is sandwiched between a surface of the first housing (130) substantially perpendicular to the rotation axis (A1) and a surface of the second housing (230) substantially perpendicular to the rotation axis (A1).

5. The assembly (1) according to any one of claims 1 to 4, comprising at least one bearing (501, 502) providing a mechanical connection between the first housing (130) and the rotor (110), or between the second housing (230) and a shaft (400) rotatably coupled to the rotor (110), wherein the elastically deformable means (301, 302) is positioned opposite the bearing (501, 502).

6. The assembly (1) according to any one of claims 1 to 5, wherein the elastically deformable means (301, 302) is annular.

7. The assembly (1) according to any one of claims 1 to 6, wherein the elastically deformable means (301, 302) are made of an elastomer.

8. The assembly (1) according to any one of claims 1 to 7, wherein the elastically deformable means (301, 302) are compressed when the electromachine (100) is stopped.

9. The assembly (1) according to any one of claims 1 to 8, further comprising a powertrain element (200) housed in the second housing (230), wherein the powertrain element (200) is one of a transmission, a reduction gear, or other electrical machine.

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