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US-12620844-B2 - Stator body and method for assembling such a stator body

US12620844B2US 12620844 B2US12620844 B2US 12620844B2US-12620844-B2

Abstract

A stator body for an electric machine, including: —at least one fixing support centered on a longitudinal axis, —teeth which are designed to accept coils of electrically conducting wire and which are uniformly distributed about the longitudinal axis, and—fixing means each suitable for fixing one of the teeth to the fixing support. Each fixing means includes: —at least one first key at least partially housed in a first keyway provided in the tooth, —at least one second key at least partially housed in a second keyway provided in the fixing support, and—at least one immobilizing element designed to immobilize the first key with respect to the second key.

Inventors

  • Nicolas Marchal

Assignees

  • RENAULT S.A.S.
  • WHYLOT

Dates

Publication Date
20260505
Application Date
20220624
Priority Date
20210625

Claims (12)

  1. 1 . A stator body for an electric machine, comprising: at least one fixing support centred on a longitudinal axis, teeth which are designed to accept coils of electrically conducting wire and which are uniformly distributed about the longitudinal axis, and fixing means each suitable for fixing one of said teeth to the fixing support, wherein each fixing means comprises: at least one first key at least partially housed in a first keyway provided in the tooth, at least one second key at least partially housed in a second keyway provided in the fixing support, and at least one immobilising element designed to immobilise the first key with respect to the second key.
  2. 2 . The stator body according to claim 1 , wherein each first and second keyway has a bottom and two side walls inclined towards each other which together delimit an elongated orifice of less width than the bottom, the orifice of the first keyway being superimposed on the orifice of the second keyway.
  3. 3 . The stator body according to claim 1 , wherein the first keyway opens on either side of the tooth, the first key projects on either side of the tooth and the immobilising element is accessible from the side of the tooth.
  4. 4 . The stator body according to claim 1 , wherein two separate second keys, housed in the same second keyway or in two second coaxial keyways, are provided.
  5. 5 . The stator body according to claim 1 , wherein the immobilising element is designed to exert a tensile force from the first key towards the second key.
  6. 6 . The stator body according to claim 1 , wherein the immobilising element includes a plastically deformable part which is integrally formed with the second key and wherein the first key delimits a passage for the plastically deformable part, on the edge of which the plastically deformable part is designed to be crimped.
  7. 7 . The stator body according to claim 1 , wherein the second keyway is extended by an insertion ramp the cross section of which gradually widens from the second keyway.
  8. 8 . The stator body according to claim 1 , wherein the fixing support forms part of a casing of a stator.
  9. 9 . The stator body according to claim 1 , wherein each fixing also includes a relief which extends projecting or recessed from the fixing support and to which is hooked on the tooth.
  10. 10 . An electric machine including a rotor and two stator bodies in accordance with claim 1 , located on either side of the rotor.
  11. 11 . A method for assembling a stator body in accordance with claim 1 , comprising: a step of inserting the first key into the first keyway provided in the tooth, a step of engaging each second key in the second keyway provided in the fixing body, after the insertion step, a step of placing the tooth resting against the fixing support, so that the first keyway is superimposed above the second keyway, and after the placement step and the engagement step, a step of immobilising the first key on the second key using the immobilising element.
  12. 12 . The assembly method according to claim 11 , wherein the immobilisation step is implemented by crimping the immobilising element.

Description

This application is the U.S. national phase of International Application No. PCT/EP2022/067423 filed Jun. 24, 2022, which designated the U.S. and claims priority to FR Patent Application No. 2106814 filed Jun. 25, 2021, the entire contents of each of which are hereby incorporated by reference. BACKGROUND OF THE INVENTION Technical Field of the Invention The present invention generally relates to the field of electric machines. It relates more particularly to a stator body for an electric machine, comprising: at least one fixing support centred on a longitudinal axis,teeth which are designed to accept coils of electrically conducting wire and which are uniformly distributed about the longitudinal axis, andfixing means each suitable for fixing one of said teeth to the fixing support. The invention finds a particularly advantageous application in an axial flux electric machine, although it also applies to radial flux electric machines. Description of the Prior Art An electric or hybrid motor vehicle includes a powertrain which comprises an electric machine. The electric machine includes a rotor that is mounted on an output shaft, which is connected to the drive wheels of the vehicle. For example, the electric machine can be of the axial flux type and include a casing in two parts, which houses a disk-shaped rotor flanked by two stators. The stators are then slightly spaced apart on either side of the rotor to avoid any friction when the rotor rotates. Thus, on each side of the rotor there is a space called an “air gap”. The performance of the electric machine depends on the value of these air gaps (it must be minimal), their consistency all around the axis of rotation of the rotor, and the symmetry of these air gaps on either side of the rotor. The slightest error in geometry has consequences on the performance of the motor and its lifespan. For example, it is understood that a difference in values between the two air gaps causes the rotor to be attracted by the nearest stator. This force can be significant. It can also be cyclical and cause fatigue of the materials making up the electric machine. These problems are inherent to the very concept of an axial flux electric machine. It is therefore important to ensure that the stators are well assembled and securely fixed in the casing. The major problem which then arises concerns the fixing of the teeth around which the coils of electrical wires are wound. Indeed, the methods considered for achieving this fixing are either very bulky, unreliable, or poorly resistant to vibrations. PRESENTATION OF THE INVENTION In order to overcome the aforementioned disadvantages of the prior art, the present invention proposes to fix the teeth by means of keys. More particularly, according to the invention, provision is made of an electric machine as defined in the introduction, wherein each fixing means comprises: at least one first key at least partially housed in a first keyway provided in the tooth,at least one second key at least partially housed in a second keyway provided in the fixing support, andat least one immobilising element designed to immobilise the first key with respect to the second key. Thus, thanks to the invention, it is possible to bring the keys into the keyways then place each tooth on the fixing support such that the keys overlap. Therefore, it is possible to fix the keys together in order to immobilise the tooth against the fixing support. The use of several keys allows the tooth to be assembled to the fixing support without requiring a lot of space. Thus, if the fixing support has a flat area wherein the keyways are located, and a rim which rises around the flat area, it is possible to engage the keys taking advantage of the reduced space between the rim and the teeth, thanks to the reduced length of the keys used. Preferably, each key is housed in one of the two keyways only. In other words, the first key does not extend into the second keyway, and vice versa. Other advantageous and non-limiting features of the electric machine in accordance with the invention, taken individually or in all technically possible combinations, are as follows: each first and second keyway has a bottom and two side walls inclined towards each other which together delimit an elongated orifice of less width than the bottom, the orifice of the first keyway being superimposed on the orifice of the second keyway;the first keyway opens on either side of the tooth;the first key projects on either side of the tooth;each immobilising element is accessible from the side of the tooth;two separate second keys, housed in the same second keyway or in two second coaxial keyways are provided;the immobilising element is designed to exert a tensile force from the first key towards the second key;the immobilising element includes a plastically deformable part which is integrally formed with the second key;the first key delimits a passage for the plastically deformable part, on the edge of wh