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CN-122000761-A - Grounding brush assembly

CN122000761ACN 122000761 ACN122000761 ACN 122000761ACN-122000761-A

Abstract

And the grounding brush assembly. The grounding brush assembly (10) comprises a grounding brush (16) and a mounting plate (18) for the brush (16), the brush (16) being provided with a plurality of conductive fibers (20) and a support (22), the conductive fibers (20) being accommodated inside the support, the mounting plate (18) being fixed to the support (22) and being provided with a radially extending body (32), an axially extending centering portion (36), a retaining tongue (34) for retaining the support (22) in the axial direction, the assembly further comprising a bearing portion (40) constituted by a radial deformation of the centering portion (36) for retaining the support (22) in the axial direction.

Inventors

  • THOMAS PERROTIN
  • Emmanuel Benitez
  • kevin. Watio
  • Bruno Constante
  • Jean Marie Gerald
  • BENOIT ARNAULT

Assignees

  • 斯凯孚公司

Dates

Publication Date
20260508
Application Date
20251029
Priority Date
20241107

Claims (7)

  1. 1. A grounding brush assembly (10) for an electric motor (2), the electric motor (2) being provided with a shaft (6) rotating about an axis (X), a fixed seat (4) and a bearing (8), and the grounding brush assembly (10) comprising a grounding brush (16) and a brush mounting plate (18), the grounding brush (16) being provided with a plurality of conductive fibers (20) and a support (22), the conductive fibers being mounted inside the support (22), the brush mounting plate (18) being fixed to the support (22) of the brush, the mounting plate (18) comprising: -a body (32) formed by a radial portion, said brush support (22) being axially abutted against said body (32), -A centering portion (36) extending axially at least from the main body (32), extending axially on the same side as the brush support (22), offset radially outwards with respect to the support (22), and provided with an outer surface (38) defining the outer diameter of the mounting plate (18) to center the mounting plate (18) after the mounting plate (18) is mounted in the hole (12) of the seat (4) of the associated electric motor (2), The mounting plate is characterized in that the mounting plate further comprises: -a plurality of retaining tongues (34) for the support, the tongues (34) extending from the centring portion (36) radially towards the inside of the assembly (10), each tongue (34) axially bearing against the brush support (22) on axially opposite sides of the body (32), the support (22) being so axially retained on one side by the body (32) and on the other side by the retaining tongues (34), and -A plurality of bearing portions (40; 50) for the support (22), the bearing portions (40; 50) being constituted by radial deformations extending radially from the centering portion (36) towards the inside of the assembly (10), the bearing portions (40; 50) radially abutting on the upper axial surface (26) of the brush support (22).
  2. 2. The assembly (10) of claim 1, wherein the centering portion (36) is annular.
  3. 3. The assembly (10) of claim 1, wherein the centering portion (36) includes a plurality of axial portions spaced apart from one another in a circumferential direction.
  4. 4. The assembly (10) according to any one of the preceding claims, wherein the retaining tongues (34) and the bearing portions (40; 50) are alternately distributed in the circumferential direction.
  5. 5. Assembly (10) according to any one of the preceding claims, characterized in that the support portion (40) is constituted by partial radial deformations, each partial radial deformation being formed on an angular sector smaller than or equal to 5 °, preferably each partial radial deformation being formed on an angular sector smaller than or equal to 1 °.
  6. 6. Assembly (10) according to any one of claims 1 to 4, characterized in that the support portion (50) is constituted by radial deformations extending in the circumferential direction, each radial deformation being formed over an angular sector comprised between 5 ° and 40 °, preferably each radial deformation being formed over an angular sector comprised between 15 ° and 30 °.
  7. 7. An electric motor (2) comprising a seat (4), a shaft (6) and a grounding brush assembly (10) according to any one of the preceding claims, the grounding brush assembly (10) being mounted at least partially radially between the seat (4) and the shaft (6), the conductive fibres (20) of the assembly being in contact with the shaft (6).

Description

Grounding brush assembly Technical Field The present invention relates to the field of grounding devices for controlling shaft current generated in 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 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 maintained 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. Document US-A1-2021/0021180 discloses a grounding brush assembly comprising a grounding brush provided with a support and a plurality of conductive fibers mounted in the support, and an annular mounting plate provided with a plurality of tongues for radially and axially holding the grounding brush support and an annular outer flange (/ flange) radially surrounding the brush and tongues. The tongue is formed by plastic deformation of the mounting plate. Such a grounding brush assembly has a relatively large radial dimension. For electric motor applications with reduced radial compactness, such an assembly would not be installed. The present invention aims to remedy this drawback. Disclosure of Invention The present invention relates to a grounding brush assembly for an electric motor provided with a rotating shaft, a stationary seat (/ housing) and a bearing. The assembly includes a grounding brush provided with a plurality of conductive fibers and a support (support) inside which the conductive fibers are mounted. The assembly also includes a brush mounting plate secured to the brush support. The mounting plate comprises a body formed by a radial portion against which the brush support axially abuts (agains t), and a centering portion (centring portion) extending at least axially from the body, extending axially on the same side as the brush support, offset radially outwards with respect to the support, and provided with an outer surface defining an outer diameter of the mounting plate to center the mounting plate (centre) after the mounting plate is mounted in a hole of a seat of an associated electric motor. According to one general feature of the invention, the mounting plate includes a plurality of retaining tongues (RETAINING TONGUES) for the support and bearing portions (bearing portions) for the support. According to the invention, the retaining tongue extends from the centering portion radially towards the inside of the assembly. Each retaining tongue bears axially against the brush support on axially opposite sides of the body, the support thus being axially retained by the body on one side and by the retaining tongue on the other side. The support portion is constituted by a radial deformation (radial deformations) extending radially from the centering portion towards the inside of the assembly. The bearing portion radially abuts against an upper axial surface (upper axial surface) of the brush support. In one embodiment, the centering portion may be annular. Alternatively, the centering portion may include a plurality of axial portions spaced apart from each other in the circumferential direction. In one embodiment, the retaining tongues and the bearing portions are alternately distributed over the circumferential portion. According to one embodiment, the support portion is constituted by partial radial deformations, each formed on an angular sector (angular sector) less than or equal to 5 °, preferably each formed on an angular sector less than or equal to 1 °. According to an alternative embodiment, the support portion is constituted by radial deformations extending in the circumferential direction, each radial deformation being formed over an angular sector comprised between 5 ° and 40 °, preferably each radial deformation being formed over an angular sector comprised between 15 ° and 30 °. The invention also relates to an electric machine or motor com