Grounding brush assembly with improved electrical conductivity properties
A grounding brush assembly including a grounding brush and a mounting plate configured to axially and radially retain the brush, the brush providing a support and a plurality of electrically conductive fibers mounted in the support. The mounting plate is at least partially coated with an electrically conductive coating.
1 . An electrical machine comprising:
at least one grounding brush assembly, comprising:
a grounding brush, and
a mounting plate configured to axially and radially retain the brush, the brush comprising a support and a plurality of electrically conductive fibers mounted in the support, wherein
the mounting plate is at least partially coated with an electrically conductive coating;
a housing, and
a shaft, the electrically conductive fibers being bent about a bonding wire and secured such that ends of the electrically conductive wire are in contact with the shaft, wherein the housing and the shaft form a chamber in which a bearing having an outer ring is located, the at least one grounding brush assembly also being located in the chamber such that the mounting plate is located on a portion of the housing that is located radially farther from the shaft than a radially outermost surface of the outer ring,
the at least one grounding brush assembly is mounted radially between the housing and the shaft and is in radial contact with the shaft, and wherein
a radially outermost end of the at least one grounding brush assembly contacts the housing.
2 . The electrical machine according to claim 1 , wherein the support is at least partially coated with an electrically conductive coating.
3 . The electrical machine according to claim 1 , wherein the electrical conductivity of the electrically conductive coating is equal or greater than 50×10 6 Siemens/m.
4 . The electrical machine according to claim 1 , wherein the electrically conductive coating comprises a nickel-based material or a silver-based material.
5 . The electrical machine according to claim 4 , wherein the electrically conductive coating is made of pure silver.
6 . The electrical machine according to claim 4 , wherein the electrically conductive coating comprises nickel sulfamate.
7 . The electrical machine according to claim 1 , wherein the mounting plate and/or the support are made of steel or aluminum.
8 . The electrical machine according to claim 1 , wherein the mounting plate comprises a main body and a plurality of holding lugs fully coated by the electrically conductive coating.
9 . The electrical machine according to claim 1 , wherein the support comprises an axial portion and two lateral portions fully coated by the electrically conductive coating.
10 . The electrical machine according to claim 3 , wherein the electrical conductivity of the electrically conductive coating is preferably equal or greater than 62.1×10 6 Siemens/m.