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CN-121986421-A - Grounding brush and associated assembly

CN121986421ACN 121986421 ACN121986421 ACN 121986421ACN-121986421-A

Abstract

The grounding brush (30) is provided with a plurality of conductive fibers (31), a support (32), and a ring (33), the conductive fibers being mounted inside the support, and the conductive fibers being positioned inside the support around the ring. The support (32) comprises a mounting portion (34) and two lateral sides (36, 38) extending from the mounting portion and clamping the conductive fibers (31) in an axial direction. The ring (33) is at least partially made of an elastically deformable material.

Inventors

  • Emmanuel Benitez
  • BENOIT ARNAULT

Assignees

  • 斯凯孚公司

Dates

Publication Date
20260505
Application Date
20240807
Priority Date
20231018

Claims (10)

  1. 1. Grounding brush (30) comprising a plurality of conductive fibres (31) and a support (32), said conductive fibres being mounted inside said support (32), and said support (32) being provided with a mounting portion (34) and two lateral sides (36, 38) extending from said mounting portion and axially clamping said conductive fibres (31), said brush further comprising a ring (33), said conductive fibres being positioned inside said support around said ring (33), characterized in that said ring (33) is made at least partly of an elastically deformable material.
  2. 2. A brush according to claim 1, characterized in that the ring (33) is entirely made of elastically deformable material.
  3. 3. Brush according to claim 1 or 2, characterized in that the ring (33) has a circular or square profile in cross section.
  4. 4. Brush according to claim 1 or 2, characterized in that the ring (33) has a contour elongated in radial direction in cross section, in particular the ring (33) has a rectangular contour in cross section.
  5. 5. Brush according to any of the preceding claims, characterized in that the ring (33) extends radially towards the inside with respect to the lateral sides (36, 38) of the support.
  6. 6. Brush according to any of the preceding claims, characterized in that the friction coefficient of the ring (33) is at least equal to 0.2, preferably the friction coefficient of the ring (33) is at least equal to 0.25.
  7. 7. Brush according to any of the preceding claims, characterized in that the ring (33) has a shape undulating in the circumferential direction.
  8. 8. A grounding brush assembly (20) comprising a grounding brush (30) according to any of the preceding claims and a brush mounting plate (40) fixed to a support (32) of the brush.
  9. 9. The assembly of claim 8, wherein the mounting plate (40) includes a main body (42) and a plurality of retaining tongues (44), the plurality of retaining tongues (44) for axially and radially retaining the support (32) of the brush (30) and extending from the main body (42), the retaining tongues (44) radially pressing against the mounting portion (34) of the support and axially against one of the lateral sides (36, 38) of the support.
  10. 10. An electric motor comprising a seat (12), a shaft (14) and at least one grounding brush assembly (20) according to claim 9, said at least one grounding brush assembly (20) being mounted radially between said seat (12) and said shaft (14), the conductive fibers of the brush of said assembly being in contact with said shaft or said seat.

Description

Grounding brush and associated assembly Technical Field The present invention relates to the field of grounding devices for controlling shaft currents generated in electric motors or electric machines (electric motors or machines), and in particular to grounding brush assemblies. Background In an electric motor or machine, at least one rolling bearing is mounted between a seat (/ housing) of the electric motor or machine and a rotating shaft to support the shaft. In operation, a potential difference may occur between the shaft and the seat of the electric motor or electric machine when the shaft rotates, thereby generating a current between the inner ring (fixed to the shaft) and the outer ring (fixed to the seat) of the rolling bearing. The current flowing through the constituent parts of the rolling bearing may damage the constituent parts, in particular the rolling elements and the raceways formed on the inner ring and the outer ring. The discharge may also generate vibrations. To compensate for these drawbacks, it is known to ground the rotating shaft (earth or ground) by using a grounding brush including conductive fibers. The grounding brush is typically mounted in a hole in the seat of the electric motor such that the free ends of the fibers are in radial contact with the outer surface of the rotating shaft. By virtue of the conductivity of the fibres, the brush is kept at the same potential as the seat of the electric motor. The inner ring and the outer ring of the rolling bearing are also at the same potential, which reduces or even eliminates problematic discharge through the rolling bearing. For further details regarding the design of such a grounding brush assembly, reference may be made for example to US-A1-2021/0021180, which describes an assembly provided with a grounding brush comprising a plurality of conductive fibers, a support and a steel ring, the conductive fibers being mounted inside the support, the steel ring being mounted inside the support and the conductive fibers being bent (/ folded) around the steel ring (folded), and an annular mounting plate comprising a plurality of tongues for radially and axially holding the support of the brush. With this type of design, the conductive fibers may be lost from the support or these fibers may break (break), resulting in contamination of the associated electric motor or inside the electric machine. The present invention aims to remedy this drawback. Disclosure of Invention The invention relates to a grounding brush comprising a plurality of conductive fibers and a support (support), the conductive fibers being mounted inside the support. The support comprises a mounting portion and two lateral sides (/ lateral flanks) (LATERAL FLANKS) extending from the mounting portion and clamping the conductive fibers in an axial direction. The brush also includes a ring around which the conductive fibers are positioned inside the support. The support comprises a mounting portion, two lateral sides (/ lateral flanks) (LATERAL FLANKS) extending from the mounting portion and clamping (gripping) the conductive fibers in an axial direction. According to a general feature, the ring is made at least in part of an elastically deformable material (ELASTICALLY DEFORMABLE MATERIAL). Thus, due to the material used, the ring can deform under an external load and if the load ceases, the ring can return to its original position by elasticity. Due to the manufacturing method of the brush and the crimping of the sides (/ flanks) (flanks) of the support against the fibers, the design of such a brush limits the risk of fiber loss or breakage that exists in the case of conventional brushes provided with steel rings. In particular, depending on the forces applied to the fibers by the sides of the support during such crimping (/ crimping/receiving) (crimping), the ring may deform and limit the pressure that these sides apply to the fibers. The ring thus forms a part that absorbs the pressure exerted on the conductive fibres by the sides (flanks) of the support, due to its ability to deform. The mounting portion and the lateral sides of the support define a channel open at a radially inner side, inside which the conductive fibers are positioned in part. The ring is positioned at least partially inside the channel. As a preferred embodiment, the ring is entirely made of an elastically deformable material. Alternatively, the ring may be made partly of an elastically deformable material and partly of a rigid material. The ring may have a circular or square profile in cross section. Advantageously, the ring may have a profile elongated in a radial direction in cross section. In this case, the contact area between the ring and the conductive fibers increases, further limiting the risk of fiber displacement and loss. When the ring has a contour elongated in the radial direction in cross section, the cross section may be rectangular, for example. In order to increase the contact are