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CN-122000762-A - Grounding brush assembly

CN122000762ACN 122000762 ACN122000762 ACN 122000762ACN-122000762-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), a retaining tongue (34) for axially and radially retaining the support (22) and an axially extending centering portion (36), the mounting plate (18) comprising at least one bearing portion (40) radially abutting the brush support (22) and providing a bearing surface for a tool for inserting the assembly (10) into the seat (4).

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 extending radially outwards with respect to the support (22), -A plurality of centering tongues (34) protruding axially with respect to the body (32), each tongue (34) locally surrounding a support (22) of the brush (16) in radial direction and in radial contact with the support (22), the support (22) being held axially supported against the body (32) of the mounting plate (18) by the tongues (34), and -A centering portion (36) extending axially at least from the main body (32), extending axially on the same side as the tongue (34), offset radially outwards with respect to the support (22) and the tongue (34), 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), Characterized in that the mounting plate (18) further comprises at least one supporting portion (40) protruding radially towards the inside of the assembly (10), the supporting portion (40) being formed by: -a first curved portion (42) extending axially from the body (32) and radially abutting on an upper axial surface (26) of the brush support (22), and -A second curved portion (44) extending radially between the first curved portion (42) and the centering portion (46), the second curved portion (44) defining an axial bearing surface for a tool for positioning the assembly (10).
  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) of any one of the preceding claims, wherein the mounting plate (18) comprises a plurality of support portions (40) spaced apart from one another in a circumferential direction.
  5. 5. The assembly (10) according to claim 4, wherein the retaining tongues (34) and the support portions (40) are alternately distributed in the circumferential direction.
  6. 6. The assembly (10) according to any one of the preceding claims, wherein the second curved portion (44) is continued by an axial portion (37) of the centering portion (36).
  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 is press-fit (force-fitted) into the bore of the seat, and thus the grounding brush assembly is difficult to remove. 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 extending radially outwards with respect to the support, a plurality of centering tongues (centring tongues) protruding axially with respect to the radial portion, each tongue locally surrounding radially the support of the brush and being in radial contact with the support, the support being held by the tongues bearing axially against the radial portion of the mounting plate, and a centering portion (centring portion) extending at least from the body axially on the same side as the tongues in the axial direction, offset radially outwards with respect to the support and the tongues, 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 a general feature of the invention, the mounting plate further comprises at least one bearing portion (bearing portion) protruding radially towards the inside of the assembly. The bearing portion is formed by a first curved portion extending axially from the body and radially abutting against an upper axial surface (upper axial surface) of the brush support, and a second curved portion extending radially between the first curved portion and the centering portion, the second curved portion defining an axial bearing surface for a tool for positioning the assembly. Both the centering portion and the first curved portion of the bearing portion extend from the body in the same axial direction. The centering portion has a diameter greater than a diameter of the first curved portion, defining a radial offset between the centering portion and the first curved portion. 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 mounting plate includes a plurality of support portions spaced apart from one another in the circumferential direction. In one embodiment, the retaining tongues and the bearing portions are alternately distributed in the circumferential direction. In an advantageous embodiment, the second curved portion is continued (continued) by an axial portion of the centering portion.