Shaft current control brush ring assembly

1. A shaft current control brush ring assembly for a motor having a faceplate and a shaft, said assembly comprising:

a cup having an outer band, an inner barrier and an outer lip, wherein the inner barrier and the outer lip are positioned on opposite axial sides of the outer band;

a brush assembly disposed in said cup and held in axial compression between said inner barrier and said outer lip, said brush assembly having an electrically conductive annular inner plate, an electrically conductive annular outer plate and a plurality of electrically conductive filaments secured between said electrically conductive annular inner plate and said electrically conductive annular outer plate, said electrically conductive filaments having distal ends extending radially inwardly beyond said electrically conductive annular inner and annular outer plates; and

said cup with said brush assembly therein being adapted to be disposed around the shaft and secured to the faceplate, such that electrical charge from the shaft is transferred to the cup via an electrical path formed by the electrically conductive filaments and the electrically conductive annular inner and annular outer plates.

2. The shaft current control brush ring assembly of claim 1 , said cup being secured in a recess in the faceplate via an interference fit.

3. The shaft current control brush ring assembly of claim 1 , said cup being secured against a surface of said faceplate.

4. The shaft current control brush ring assembly of claim 1 , including a clamp secured to the faceplate and holding said cup against an outer surface of the faceplate.

5. The shaft current control brush ring assembly of claim 4 , said clamp including a fastener engaged in a hole in said faceplate.

6. The shaft current control brush ring assembly of claim 5 , said clamp having a base against the outer surface of the faceplate, a riser projecting outwardly from said base along said band and a hooked end engaged against said outer lip.

7. The shaft current control brush ring assembly of claim 1 , wherein each of the plurality of electrically conductive filaments comprises a diameter of less than approximately 150 microns.

8. The shaft current control brush ring assembly of claim 1 , wherein the electrically conductive annular inner and annular outer plates are each made of a material comprising at least one of aluminum, stainless steel, bronze, or copper.

9. A shaft current control brush ring assembly for a motor having a faceplate and a motor shaft, the assembly comprising:

a cup having an outer band, an inner barrier and an outer lip, wherein the inner barrier and the outer lip are positioned on opposite axial sides of the outer band; and

a brush assembly disposed in said cup and held in axial compression between said inner barrier and said outer lip, said brush assembly having a plurality of electrically conductive filaments configured to be arranged circumferentially around the motor shaft, and wherein the brush assembly is configured to transfer electrical charge from the motor shaft to the cup at least through the plurality of electrically conductive filaments.

10. The shaft current control brush ring assembly of claim 9 , wherein the brush assembly comprises:

an electrically conductive annular inner plate; and

an electrically conductive annular outer plate;

wherein the plurality of electrically conductive filaments is secured between the electrically conductive annular inner and annular outer plates, and wherein the electrically conductive filaments and the electrically conductive annular inner and annular outer plates collectively provide an electrical path for the transfer of the electrical charge from the motor shaft to the cup.

11. The shaft current control brush ring assembly of claim 10 , said brush assembly having a shield disposed against said electrically conductive annular outer plate and held thereagainst by said outer lip.

12. The shaft current control brush ring assembly of claim 11 , including a slinger disposed outwardly of said shield.

13. The shaft control current brush ring assembly of claim 9 , wherein the outer lip is oriented outwardly with respect to the faceplate and in an angled radial direction towards an axis of rotation of the motor shaft.

14. The shaft current control brush ring assembly of claim 9 , wherein the plurality of electrically conductive filaments is configured to transfer electrical charge from the motor shaft to the cup via direct contact with the motor shaft.

15. The shaft current control brush ring assembly of claim 9 , wherein the plurality of electrically conductive filaments is configured to be spaced from the motor shaft by a gap, and wherein the electrical charge is transferred indirectly from the motor shaft to the cup via an electrical field across the gap.

16. An electric motor comprising:

a faceplate;

a motor shaft extending outwardly of said faceplate;

a grounding circuit;

a shaft current control brush ring assembly disposed around said motor shaft and secured to said faceplate, said shaft current control brush ring assembly including:

a cup having an outer band, an inner barrier and an outer lip, wherein the inner barrier and the outer lip are positioned on opposite axial sides of the outer band; and

a brush assembly disposed in said cup and held in axial compression between said inner barrier and said outer lip, said brush assembly having an annular inner plate, an annular outer plate and a plurality of filaments secured between said annular inner plate and said annular outer plate, said filaments having distal ends extending radially inwardly beyond said annular inner and annular outer plates; and

said cup with said brush assembly therein being disposed around said motor shaft and said cup being secured to said motor faceplate;

wherein the electric motor is configured to transfer an electrical charge present on the motor shaft from the motor shaft to the grounding circuit through the plurality of filaments, the annular inner and outer plates, and the cup.

17. The motor of claim 16 , including a recess defined in said faceplate, and said cup being secured in said recess by an interference fit.

18. The motor of claim 16 , including a clamp secured to the faceplate and said clamp holding said cup against an outer surface of said faceplate.

19. The motor of claim 18 , said clamp having a base against said outer surface of said faceplate, a riser projecting outwardly from said base along said outer band of said cup, and a hooked end of said clamp engaged against said outer lip.

20. The motor of claim 16 , said brush assembly having a shield disposed against said annular outer plate and held thereagainst by said outer lip, said shield extending radially inwardly beyond said annular outer plate.