WO2008130851A1 - Improved grounding brush system for mitigating electrical current on rotating shafts - Google Patents
Improved grounding brush system for mitigating electrical current on rotating shafts Download PDFInfo
- Publication number
- WO2008130851A1 WO2008130851A1 PCT/US2008/059816 US2008059816W WO2008130851A1 WO 2008130851 A1 WO2008130851 A1 WO 2008130851A1 US 2008059816 W US2008059816 W US 2008059816W WO 2008130851 A1 WO2008130851 A1 WO 2008130851A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- layer
- brush system
- shaft
- grounding brush
- motor
- Prior art date
Links
Classifications
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02K—DYNAMO-ELECTRIC MACHINES
- H02K11/00—Structural association of dynamo-electric machines with electric components or with devices for shielding, monitoring or protection
- H02K11/40—Structural association with grounding devices
Definitions
- the present invention relates generally to grounding assemblies, and, more particularly, to grounding assemblies for moving objects including rotating shafts such as motor shafts, turbine shafts and other moving components conductively linked to components that create an electrical charge, or that may experience a buildup of electrical charge.
- the electrical energy burst creates fusion craters, and particulate from the crater formation remains inside sealed bearing. Both the fusion crater and the particulate material in the bearing act to disturb the free rotation of the bearing, which can lead to physical damage and premature bearing failure.
- a number of mitigation technologies are known to have been used in attempts to overcome this problem.
- Known attempts include using conductive bearing grease, insulating the bearings and using copper/phosphorus brushes and a Faraday shield.
- a common, somewhat cost-effective solution is to ground the shaft using spring-loaded copper brushes that provide a continuous flow of current to ground.
- copper brushes can wear out rapidly, requiring frequent, periodic service and replacement.
- oxide build-up on the shaft and other barriers between the brushes and the shaft reduce the current flow and cause a burst of electrical energy across the brush and shaft.
- Spring-loaded brushes also tend to vibrate due to alternating frictional relationships between the brush and the shaft surface. Vibration of the brushes, from whatever cause, can result in undesirable sparking.
- grounding brushes that include conductive filaments in a holder surrounding the shaft.
- the brush with thin filaments can be used as a non- contacting ionizer to reduce electrical charges on the isolated shaft or on an isolated roller.
- the thin, light filaments can also be used as a contacting conductor against a rotating shaft or other moving surface.
- the effectiveness of the thin filament grounding brushes either as a non-contacting ionizer or as a contacting conductor can be compromised by properties of the surface with which it interacts. Corrosion of the shaft or other surface can adversely affect performance.
- the grounding performance of a new motor can decrease over time with corrosion of the shaft, and retrofitting a grounding system of this type can be problematic if the motor shaft is corroded.
- the present invention provides a conductive component electrically connectable to a rotating shaft or other moving component for operating with a fixed brush in either a contacting or non-connecting relationship of a grounding brush system.
- FIG. 1 is a perspective view of a motor having a grounding brush system in accordance with the present invention
- FIG. 2 is a perspective view of a shaft collar used in a grounding brush system shown in Fig. 1 ;
- FIG. 3 is a fragmentary cross-sectional view of the motor and grounding brush system shown in Fig. 1.
- grounding brush system 10 designates a grounding brush system in accordance with the present invention.
- Grounding brush system 10 is installed on a motor 12 and specifically against a housing faceplate 14 of motor 12 for dissipating electrical charges that may build up on a shaft 16 of motor 12.
- grounding brush system 10 can be provided in a variety of different sizes for use in motors of different types and on shafts 16 of different diameters.
- Grounding brush system 10 also can be used on rotating shafts of turbines, conveyors and other assemblies and constructions that may build up an electrical charge.
- Use of the present invention is not limited to electric motors, and motor 12 is shown and described only as one suitable and advantageous use for the present invention.
- Grounding brush system 10 includes a shaft collar 20 mounted on and surrounding shaft 16 and a brush ring assembly 22 secured to motor faceplate 14 via a mounting plate 24.
- Brush ring assembly 22 generally surrounds collar 20 and is operatively arranged between shaft collar 20 and mounting plate 24 to dissipate static or other charges that build on motor shaft 16 during operation of motor 12 through the ground of motor 12.
- Shaft collar 20 is adapted to increase the effectiveness of the micro fiber grounding brush system for mitigating electrical currents on rotating surfaces.
- Collar 20 is made of or coated with highly conductive materials, such as, for example, silver, gold, copper or nickel. Preferably, the materials are both highly conductive and resistant to corrosion and other conductivity deteriorating phenomenon. While collar 20 can be made of such materials it also can be made of less expensive conductive materials and coated with highly conductive and deterioration resistant materials on the outer surface thereof in a position to interact electrically with brush ring assembly 22.
- collar 20 includes an anchor ring 26 and a contact ring 28 adjacent anchor ring 26.
- Contact ring 28 has a highly conductive layer 30 of the highly conductive material, such as gold, silver, copper and nickel, for example, disposed on an outer surface thereof.
- collar 20 can be secured to shaft 16 via set screws 32 or the like received in threaded holes 34. Screws 32 establish intimate electrical contact between collar 20 and shaft 16.
- collar 20 can be of two or more segments clamped against shaft 16 to provide direct electrical contact of collar 20 against shaft 16.
- highly conductive layer 30 can be provided directly on a surface of a rotating shaft or other moving component to be grounded. For example, conductive inks or paints can be used and applied directly to the surface.
- Brush ring assembly 22 includes an annular body 40 and a brush assembly 42 disposed therein.
- Body 40 includes an outer segment 44, an inner segment 46 and a base 48. Together, outer segment 44, inner segment 46 and base 48 form an annular channel in which brush assembly 42 is disposed.
- Body 40 is made of conductive materials, such as metal including, but not limited to aluminum, stainless steel, bronze and copper. Body 40 also can be made of conductive plastic.
- Brush assembly 42 includes a plurality of individual fiber-like conductive filaments 50 that may be arranged individually in a substantially continuous annular ring, or in a plurality of fiber bundles arranged circumferentially around shaft 16.
- each filament 50 is a fine, hair-like filament made from carbon fibers, stainless steel, conductive plastics such as acrylic or nylon fibers, or any other conductive fiber-type filament that can be provided with diameters sufficiently small to induce ionization when in the presence of an electrical field.
- conductive filaments 50 generally have diameters less than about 150 microns.
- conductive filaments 50 are conductive filaments having diameters within a range of about 5 microns to about 100 microns.
- conductive filaments 50 can be larger fibers of conductive material that are held in contact with layer 30.
- Conductive filaments 50 are secured within body 40 by an anchor structure.
- Anchor structure 52 is electrically conductive and may be in the form of clamping structure such as plates between which conductive filaments 50 are held.
- anchor structure 52 can be a conductive body of filler material such as conductive plastic, conductive adhesive or the like anchoring conductive filaments 50 in body 40.
- Portions of distal ends 54 of conductive filaments 50 extend past an inner surface 56 of anchor structure 52 and radially inwardly of outer and inner segments 44, 46 toward shaft 16 and layer 30 of collar 20 on shaft 16.
- the thin, lightweight conductive filaments 50 can physically contact layer 30 for direct transfer of electrical charge from shaft 16 without significant wear during operation.
- distal ends 54 of filaments 50 also can be provided in a closely spaced relationship to layer 30 such that, as an electric field is generated by charge building on shaft 16, an ionized field is created, allowing indirect transfer of charge from shaft 16 to filaments 50.
- the fine, lightweight filaments 50 are in contact with layer 30 when motor 12 is at rest or is operating at slow speed. As the speed of shaft 16 increases during startup and use, air currents move filaments 50 away from layer 30.
- Mounting plate 24 is made of electrically conductive material such as metal, including but not limited to aluminum, stainless steel, bronze and copper. Mounting plate 24 also can be made of electrically conductive plastics. Annular body 40 is held to mounting plate 24 by a plurality of clamps 60 and screws or bolts 62, three such clamps 60 with associated screws 62 being shown in the exemplary embodiment. It should be understood that more or fewer clamps 60 and associated screws 62 can be used, and other structure for securing annular body 40 to or against mounting plate 24 also can be used. In still other embodiments, mounting plate 24 and annular body 40 can be made as or fabricated to a single body. However, maintaining mounting plate 24 and annular body 40 as separate but connected structures allows for disassembly for servicing. For example, annular body 40 can be removed by releasing clamps 60 without disconnecting mounting plate 24 from a motor 12
- Mounting plate 24 is connected to motor 12 by a threaded rod or bolt 64 extending axially into and/or through motor 12.
- Bolts 64 are received in elongated slots 66 provided in mounting plate 24. Accordingly, mounting plate 24 is adjustably positionable relative to motor 12 and can be used on motors of different diameters to receive bolts 64 positioned at different radial distances from shaft 16. In the exemplary embodiment, three bolts 64 and associated slots 66 are shown; however, mounting plate 24 of different configurations can be provided so as to accommodate different size and structures for motor 12.
- Collar 20 is secured to shaft 16 to establish electrical conductivity between them.
- the surface of shaft 16 can be cleaned to remove oxidation, dirt or other conductivity limiting substances.
- Electrical charge that builds on shaft 16 during use of motor 12 is transferred from shaft 16 to collar 20 by the direct physical contact established between them, including through set screws 32, anchor ring 26 and contact ring 28 to also build in layer 30.
- Transfer of charge from layer 30 to filaments 50 occurs directly by touching contact of filaments 50 against layer 30, or indirectly by ionization if a spaced relationship is provided between layer 30 and filaments 50.
- From filaments 50 the electrical charge can transfer through body 40 and mounting plate 24 to housing faceplate 14 and the ground connection of motor 12. Charges that build on shaft 16 are dissipated to ground through grounding brush system 10 before arcing can occur.
- layer 30 and conductive filaments 50 can be optimized by selecting materials that function well together for either minimally spaced close proximity and ionizing indirect transfer, or for physical touching and direct transfer from layer 30.
- Collar 20 establishes and maintains good electrical contact with shaft 16 even if exposed surfaces of shaft 16 corrode over time, and the properties of collar 16 and particularly layer 30 thereon maintain a high level of performance by grounding brush system 10.
Landscapes
- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Motor Or Generator Frames (AREA)
- Elimination Of Static Electricity (AREA)
- Motor Or Generator Current Collectors (AREA)
Abstract
An improved grounding brush system (10) for mitigating electrical current on a moving object such as a rotating shaft (16) includes an electrically conductive layer (30) applied to the object and associated with a brush assembly for conducting electrical current from the moving object to ground.
Description
IMPROVED GROUNDING BRUSH SYSTEM FOR MITIGATING ELECTRICAL CURRENT ON ROTATING SHAFTS
CROSS-REFERENCE TO RELATED APPLICATIONS
[01] The present application claims the benefits of United States Provisional
Application Serial No. 60/925,833 filed on April 23, 2007.
TECHNICAL FIELD
[02] The present invention relates generally to grounding assemblies, and, more particularly, to grounding assemblies for moving objects including rotating shafts such as motor shafts, turbine shafts and other moving components conductively linked to components that create an electrical charge, or that may experience a buildup of electrical charge.
BACKGROUND ART
[03] Shaft induced electrical current is experienced in electric motors, and commonly in three-phase motors driven by variable speed drives. Variable speed drives utilize pulse width modulation technology to vary the speed of AC motors, thereby allowing use of less-expensive AC motors in applications where more expensive DC motors had been used previously. A drawback to the use of AC motors with variable speed drives is that higher common mode voltage (CMV) is generated by the variable speed drive, which increases shaft induced currents.
[04] Voltage on the motor shaft induces current flow through the shaft bearings to the motor frame and then to ground. While the motor is running, the bearings become more resistive to current flow, causing a buildup of charge on the shaft surfaces. Over a short period of time, the CMV causes electrical charges to build to a high level. As the electrical charges pass the threshold level of the least electrically resistive path, sometimes through the ball bearings on the shaft, an instantaneous burst or discharge of electrical energy passes along the path. The discharge can cause electric discharge machining (EDM) along the path, which can damage the surfaces of the bearing races and the balls in the bearing if the least resistive path is
through the bearings. The electrical energy burst creates fusion craters, and particulate from the crater formation remains inside sealed bearing. Both the fusion crater and the particulate material in the bearing act to disturb the free rotation of the bearing, which can lead to physical damage and premature bearing failure.
[05] A number of mitigation technologies are known to have been used in attempts to overcome this problem. Known attempts include using conductive bearing grease, insulating the bearings and using copper/phosphorus brushes and a Faraday shield. A common, somewhat cost-effective solution is to ground the shaft using spring-loaded copper brushes that provide a continuous flow of current to ground. However, copper brushes can wear out rapidly, requiring frequent, periodic service and replacement. Additionally, oxide build-up on the shaft and other barriers between the brushes and the shaft reduce the current flow and cause a burst of electrical energy across the brush and shaft. Spring-loaded brushes also tend to vibrate due to alternating frictional relationships between the brush and the shaft surface. Vibration of the brushes, from whatever cause, can result in undesirable sparking.
[06] It is known to use grounding brushes that include conductive filaments in a holder surrounding the shaft. The brush with thin filaments can be used as a non- contacting ionizer to reduce electrical charges on the isolated shaft or on an isolated roller. The thin, light filaments can also be used as a contacting conductor against a rotating shaft or other moving surface. However, the effectiveness of the thin filament grounding brushes either as a non-contacting ionizer or as a contacting conductor can be compromised by properties of the surface with which it interacts. Corrosion of the shaft or other surface can adversely affect performance. The grounding performance of a new motor can decrease over time with corrosion of the shaft, and retrofitting a grounding system of this type can be problematic if the motor shaft is corroded.
[07] What is needed in the art is a grounding system that can be used effectively for a prolonged period of time under adverse conditions, and which can be installed as a retrofit or incorporated into new assemblies.
DISCLOSURE OF THE INVENTION
[08] The present invention provides a conductive component electrically connectable to a rotating shaft or other moving component for operating with a fixed brush in either a contacting or non-connecting relationship of a grounding brush system.
[09] Other features and advantages of the invention will become apparent to those skilled in the art upon review of the following detailed description, claims and drawings in which like numerals are used to designate like features.
BRIEF DESCRIPTION OF THE DRAWINGS
[10] Fig. 1 is a perspective view of a motor having a grounding brush system in accordance with the present invention;
[11] Fig. 2 is a perspective view of a shaft collar used in a grounding brush system shown in Fig. 1 ;
[12] Fig. 3 is a fragmentary cross-sectional view of the motor and grounding brush system shown in Fig. 1.
[13] Before the embodiments of the invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangements of the components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments and of being practiced or being carried out in various ways. Also, it is understood that the phraseology and terminology used herein are for the purpose of description and should not be regarded as limiting. The use herein of "including", "comprising" and variations thereof is meant to encompass the items listed thereafter and equivalents thereof, as well as additional items and equivalents thereof.
BEST MODE FOR CARRYING OUT THE INVENTION
[14] Referring now more specifically to the drawings and to Fig. 1 in particular, numeral 10 designates a grounding brush system in accordance with the present
invention. Grounding brush system 10 is installed on a motor 12 and specifically against a housing faceplate 14 of motor 12 for dissipating electrical charges that may build up on a shaft 16 of motor 12. It should be understood that grounding brush system 10 can be provided in a variety of different sizes for use in motors of different types and on shafts 16 of different diameters. Grounding brush system 10 also can be used on rotating shafts of turbines, conveyors and other assemblies and constructions that may build up an electrical charge. Use of the present invention is not limited to electric motors, and motor 12 is shown and described only as one suitable and advantageous use for the present invention.
[15] Grounding brush system 10 includes a shaft collar 20 mounted on and surrounding shaft 16 and a brush ring assembly 22 secured to motor faceplate 14 via a mounting plate 24. Brush ring assembly 22 generally surrounds collar 20 and is operatively arranged between shaft collar 20 and mounting plate 24 to dissipate static or other charges that build on motor shaft 16 during operation of motor 12 through the ground of motor 12.
[16] Shaft collar 20 is adapted to increase the effectiveness of the micro fiber grounding brush system for mitigating electrical currents on rotating surfaces. Collar 20 is made of or coated with highly conductive materials, such as, for example, silver, gold, copper or nickel. Preferably, the materials are both highly conductive and resistant to corrosion and other conductivity deteriorating phenomenon. While collar 20 can be made of such materials it also can be made of less expensive conductive materials and coated with highly conductive and deterioration resistant materials on the outer surface thereof in a position to interact electrically with brush ring assembly 22.
[17] In the preferred embodiment shown, collar 20 includes an anchor ring 26 and a contact ring 28 adjacent anchor ring 26. Contact ring 28 has a highly conductive layer 30 of the highly conductive material, such as gold, silver, copper and nickel, for example, disposed on an outer surface thereof. In the inner diameter of collar 20 can be configured to engage the outer surface of shaft 16. Alternatively, collar 20 can be secured to shaft 16 via set screws 32 or the like received in threaded holes 34. Screws 32 establish intimate electrical contact between collar 20 and shaft 16. In
another variation thereof, collar 20 can be of two or more segments clamped against shaft 16 to provide direct electrical contact of collar 20 against shaft 16. It should be understood also that in some applications of the present invention highly conductive layer 30 can be provided directly on a surface of a rotating shaft or other moving component to be grounded. For example, conductive inks or paints can be used and applied directly to the surface.
[18] Brush ring assembly 22 includes an annular body 40 and a brush assembly 42 disposed therein. Body 40 includes an outer segment 44, an inner segment 46 and a base 48. Together, outer segment 44, inner segment 46 and base 48 form an annular channel in which brush assembly 42 is disposed. Body 40 is made of conductive materials, such as metal including, but not limited to aluminum, stainless steel, bronze and copper. Body 40 also can be made of conductive plastic.
[19] Brush assembly 42 includes a plurality of individual fiber-like conductive filaments 50 that may be arranged individually in a substantially continuous annular ring, or in a plurality of fiber bundles arranged circumferentially around shaft 16. In one exemplary embodiment each filament 50 is a fine, hair-like filament made from carbon fibers, stainless steel, conductive plastics such as acrylic or nylon fibers, or any other conductive fiber-type filament that can be provided with diameters sufficiently small to induce ionization when in the presence of an electrical field. In such embodiment, conductive filaments 50 generally have diameters less than about 150 microns. In one arrangement, conductive filaments 50 are conductive filaments having diameters within a range of about 5 microns to about 100 microns. Alternatively, conductive filaments 50 can be larger fibers of conductive material that are held in contact with layer 30.
[20] Conductive filaments 50 are secured within body 40 by an anchor structure.
Anchor structure 52 is electrically conductive and may be in the form of clamping structure such as plates between which conductive filaments 50 are held. As yet another alternative, anchor structure 52 can be a conductive body of filler material such as conductive plastic, conductive adhesive or the like anchoring conductive filaments 50 in body 40. Portions of distal ends 54 of conductive filaments 50 extend past an inner surface 56 of anchor structure 52 and radially inwardly of outer
and inner segments 44, 46 toward shaft 16 and layer 30 of collar 20 on shaft 16. When used with a smooth, corrosion resistant layer 30, the thin, lightweight conductive filaments 50 can physically contact layer 30 for direct transfer of electrical charge from shaft 16 without significant wear during operation. However, distal ends 54 of filaments 50 also can be provided in a closely spaced relationship to layer 30 such that, as an electric field is generated by charge building on shaft 16, an ionized field is created, allowing indirect transfer of charge from shaft 16 to filaments 50. In still another suitable arrangement, the fine, lightweight filaments 50 are in contact with layer 30 when motor 12 is at rest or is operating at slow speed. As the speed of shaft 16 increases during startup and use, air currents move filaments 50 away from layer 30.
[21] Mounting plate 24 is made of electrically conductive material such as metal, including but not limited to aluminum, stainless steel, bronze and copper. Mounting plate 24 also can be made of electrically conductive plastics. Annular body 40 is held to mounting plate 24 by a plurality of clamps 60 and screws or bolts 62, three such clamps 60 with associated screws 62 being shown in the exemplary embodiment. It should be understood that more or fewer clamps 60 and associated screws 62 can be used, and other structure for securing annular body 40 to or against mounting plate 24 also can be used. In still other embodiments, mounting plate 24 and annular body 40 can be made as or fabricated to a single body. However, maintaining mounting plate 24 and annular body 40 as separate but connected structures allows for disassembly for servicing. For example, annular body 40 can be removed by releasing clamps 60 without disconnecting mounting plate 24 from a motor 12
[22] Mounting plate 24 is connected to motor 12 by a threaded rod or bolt 64 extending axially into and/or through motor 12. Bolts 64 are received in elongated slots 66 provided in mounting plate 24. Accordingly, mounting plate 24 is adjustably positionable relative to motor 12 and can be used on motors of different diameters to receive bolts 64 positioned at different radial distances from shaft 16. In the exemplary embodiment, three bolts 64 and associated slots 66 are shown; however,
mounting plate 24 of different configurations can be provided so as to accommodate different size and structures for motor 12.
[23] Collar 20 is secured to shaft 16 to establish electrical conductivity between them. In retrofit applications the surface of shaft 16 can be cleaned to remove oxidation, dirt or other conductivity limiting substances. Electrical charge that builds on shaft 16 during use of motor 12 is transferred from shaft 16 to collar 20 by the direct physical contact established between them, including through set screws 32, anchor ring 26 and contact ring 28 to also build in layer 30. Transfer of charge from layer 30 to filaments 50 occurs directly by touching contact of filaments 50 against layer 30, or indirectly by ionization if a spaced relationship is provided between layer 30 and filaments 50. From filaments 50 the electrical charge can transfer through body 40 and mounting plate 24 to housing faceplate 14 and the ground connection of motor 12. Charges that build on shaft 16 are dissipated to ground through grounding brush system 10 before arcing can occur.
[24] The relationship between and performances of layer 30 and conductive filaments 50 can be optimized by selecting materials that function well together for either minimally spaced close proximity and ionizing indirect transfer, or for physical touching and direct transfer from layer 30. Collar 20 establishes and maintains good electrical contact with shaft 16 even if exposed surfaces of shaft 16 corrode over time, and the properties of collar 16 and particularly layer 30 thereon maintain a high level of performance by grounding brush system 10.
[25] Variations and modifications of the foregoing are within the scope of the present invention. It is understood that the invention disclosed and defined herein extends to all alternative combinations of two or more of the individual features mentioned or evident from the text and/or drawings. All of these different combinations constitute various alternative aspects of the present invention. The embodiments described herein explain the best modes known for practicing the invention and will enable others skilled in the art to utilize the invention. The claims are to be construed to include alternative embodiments to the extent permitted by the prior art.
[26] Various features of the invention are set forth in the following claims.
Claims
1. A grounding brush system for a moving object, said grounding brush- system comprising: an electrically conductive layer attached to the object; an electrically conductive body confronting said layer; conductive filaments connected to said body and have distal ends in electrical connection with said layer; and said body being connected to ground.
2. The grounding brush system of claim 1, said brush assembly being generally annular in shape.
3. The grounding brush system of claim 1, said layer being an annular layer on an annular collar.
4. The grounding brush system of claim 1, said conductive filaments being closely spaced from said layer.
5. The grounding brush system of claim 1, said conductive filaments being in physical contact with said layer.
6. The grounding brush system of claim 1, said layer being a highly conductive material selected from a group of highly conductive materials including conductive plastic, gold, silver, copper and a bronze.
7. A grounding brush system for a motor having a housing faceplate and a shaft, said grounding brush system comprising: a body electrically connected to the motor face plate; a brush assembly electrically connected to said body, said brush assembly having conductive filaments electrically connected to said body, said conductive filaments having ends near the shaft; and a collar disposed on and electrically connected to the shaft, said collar including a layer of electrically conductive material disposed between said distal ends of said conductive filaments and said shaft.
8. The grounding brush system of claim 7, said layer of electrically conductive material being a highly conductive and corrosion resistant metal selected from the group of metals including gold, silver, copper and bronze.
9. The grounding brush system of claim 7, said body being electrically connected to a mounting plate, and said mounting plate being electrically connected to the faceplate.
10. The grounding brush system of claim 9, said mounting plate being a highly conductive material selected from the group of materials including conductive plastic, aluminum, stainless steel, copper and bronze.
11. The grounding brush system of claim 9, said mounting plate having elongated slots therein and being connected to said motor via bolts extending through said slots and into the motor.
12 The grounding brush system of claim 7, said collar having an anchor ring and set screws engaging said shaft, and a contact ring adjacent said anchor ring, said layer of electrically conductive material being disposed on an outer surface of said contact ring.
13. The grounding brush system of claim 7, said brush assembly encircling said shaft.
14. The grounding brush system of claim 7, said ends of said filaments being closely spaced from said layer of electrically conductive material.
15 The grounding brush system of claim 7, said ends of said filaments being in contact with said layer of electrically conductive material.
16. An electric motor comprising: a motor housing faceplate; a motor shaft extending outwardly of said faceplate; a grounding brush system disposed around said shaft and secured to said faceplate, said grounding brush system including: an electrically conductive collar disposed on said shaft; and a brush assembly encircling said collar, said brush assembly being electrically connected to said faceplate and having conductive filaments with ends extending radially inwardly toward said collar.
17. The motor of claim 16, said collar having a layer of electrically conductive material.
18. The motor of claim 17, said layer being one of conductive plastic, silver gold, copper and bronze.
19. The motor of claim 17, said ends of said filaments being in close spaced relationship to said layer.
20. The motor of claim 17, said ends of said filaments being in physical contact with said layer.
Priority Applications (4)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
ES08745427.8T ES2441962T3 (en) | 2007-04-23 | 2008-04-10 | Improved grounding brush system to attenuate electric current in rotating shafts |
EP08745427.8A EP2137805B1 (en) | 2007-04-23 | 2008-04-10 | Improved grounding brush system for mitigating electrical current on rotating shafts |
JP2010506384A JP5281077B2 (en) | 2007-04-23 | 2008-04-10 | Improved ground brush system for reducing rotating shaft current |
CN2008800129797A CN101682234B (en) | 2007-04-23 | 2008-04-10 | Improved grounding brush system for mitigating electrical current on rotating shafts |
Applications Claiming Priority (4)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US92583307P | 2007-04-23 | 2007-04-23 | |
US60/925,833 | 2007-04-23 | ||
US12/098,573 US8189317B2 (en) | 2007-04-23 | 2008-04-07 | Grounding brush system for mitigating electrical current on rotating shafts |
US12/098,573 | 2008-04-07 |
Publications (1)
Publication Number | Publication Date |
---|---|
WO2008130851A1 true WO2008130851A1 (en) | 2008-10-30 |
Family
ID=39871506
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/US2008/059816 WO2008130851A1 (en) | 2007-04-23 | 2008-04-10 | Improved grounding brush system for mitigating electrical current on rotating shafts |
Country Status (6)
Country | Link |
---|---|
US (1) | US8189317B2 (en) |
EP (1) | EP2137805B1 (en) |
JP (1) | JP5281077B2 (en) |
CN (1) | CN101682234B (en) |
ES (1) | ES2441962T3 (en) |
WO (1) | WO2008130851A1 (en) |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US8963398B2 (en) | 2011-10-28 | 2015-02-24 | Illinois Tool Works Inc. | Current control brush assembly |
US10158274B2 (en) | 2015-05-01 | 2018-12-18 | Meidensha Corporation | Rotary machine |
DE102020215641A1 (en) | 2020-12-10 | 2022-06-15 | Zf Friedrichshafen Ag | Process for manufacturing a running surface for a sliding contact on a shaft |
Families Citing this family (47)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US8199453B2 (en) * | 2003-03-17 | 2012-06-12 | Illinois Tool Works Inc. | Shaft current control brush ring assembly |
US8604653B2 (en) | 2005-06-25 | 2013-12-10 | Inpro/Seal, LLC | Current diverter ring |
US20070278093A1 (en) * | 2006-06-02 | 2007-12-06 | Barnard Michael P | Electrical conductive contact ring for electroplating or electrodeposition |
JP2009158347A (en) * | 2007-12-27 | 2009-07-16 | Bruker Axs Kk | X-ray generator |
EP2233611A1 (en) * | 2009-03-24 | 2010-09-29 | MTV Metallveredlung GmbH & Co. KG | Layer system with improved corrosion resistance |
US8378548B2 (en) * | 2009-09-17 | 2013-02-19 | Illinois Tool Works Inc. | Current control assembly with drainage and slinger |
US8488293B2 (en) * | 2009-12-21 | 2013-07-16 | Caterpillar Inc. | Electrical bearing ground device |
JP5585211B2 (en) * | 2010-05-27 | 2014-09-10 | 日産自動車株式会社 | Power transmission device for electric vehicle |
US8734164B2 (en) * | 2011-06-28 | 2014-05-27 | Illinois Tool Works Inc. | Current control brush assembly having axial and radial filaments |
JP5704002B2 (en) | 2011-07-13 | 2015-04-22 | 株式会社Ihi | Electric motor |
WO2013086531A1 (en) | 2011-12-08 | 2013-06-13 | Inpro/Seal Llc | Current diverter ring |
US20140369821A1 (en) * | 2011-12-21 | 2014-12-18 | Pope Electric Motors Pty Ltd | Earth and/or sealing assembly for electric motors |
US9831739B2 (en) | 2012-06-18 | 2017-11-28 | Inpro/Seal Llc | Explosion-proof current diverting device |
WO2013192169A1 (en) * | 2012-06-18 | 2013-12-27 | Inpro/Seal Llc | Current diverter ring |
US9160216B2 (en) | 2013-03-14 | 2015-10-13 | Regal Beloit America, Inc. | Grounding device for electric machine and methods of assembling the same |
US9685843B2 (en) | 2013-03-14 | 2017-06-20 | Regal Beloit America, Inc. | Grounding device for electric machine and methods of assembling the same |
US9917491B2 (en) * | 2014-03-07 | 2018-03-13 | Nidec Motor Corporation | Ground ring and enclosure in an electric motor |
JP6097720B2 (en) * | 2014-04-23 | 2017-03-15 | 本田技研工業株式会社 | Conductive connector |
DE102015205475A1 (en) | 2014-06-05 | 2015-12-17 | Robert Bosch Gmbh | Electric machine |
DE102014213698A1 (en) * | 2014-07-15 | 2016-01-21 | Robert Bosch Gmbh | Electric machine with a resistor for the derivation of shaft voltages |
US10446995B2 (en) * | 2014-10-17 | 2019-10-15 | Moog Inc. | Superconducting devices, such as slip-rings and homopolar motors/generators |
DE102014115291A1 (en) * | 2014-10-21 | 2016-05-12 | Ebm-Papst Mulfingen Gmbh & Co. Kg | grounding device |
WO2016094972A1 (en) * | 2014-12-19 | 2016-06-23 | Weg Equipamentos Elétricos S.a. | System for grounding bearings of rotary electric machines, and corresponding electric machine |
CN107407396B (en) * | 2015-03-31 | 2020-11-06 | 爱知机械工业株式会社 | Power transmission device and power output device provided with same |
DE102016010926A1 (en) | 2016-03-03 | 2017-09-07 | Kaco Gmbh + Co. Kg | Shaft grounding ring |
DE102016214861A1 (en) * | 2016-08-10 | 2018-02-15 | Schaeffler Technologies AG & Co. KG | Equipotential bonding device to compensate for electrical potentials of two relatively moving components |
CN106253589A (en) * | 2016-08-16 | 2016-12-21 | 中车永济电机有限公司 | Easy care grounding device |
DE102016216909A1 (en) * | 2016-09-06 | 2018-03-08 | Bayerische Motoren Werke Aktiengesellschaft | Drive device for a motor vehicle, in particular a motor vehicle, and motor vehicle with such a drive device |
CN107947492B (en) * | 2016-10-13 | 2020-03-06 | 上海大郡动力控制技术有限公司 | Structure for eliminating current of motor shaft |
JP6330893B2 (en) * | 2016-12-05 | 2018-05-30 | 株式会社明電舎 | Rotating machine |
US10253815B2 (en) | 2017-08-29 | 2019-04-09 | Schaeffler Technologies AG & Co. KG | Rolling bearing assembly including a crimped sealing assembly having a grounding element |
EP3682512A1 (en) * | 2017-09-11 | 2020-07-22 | Illinois Tool Works Inc. | Methods and apparatus to mitigate electrical voltage on a rotating shaft |
EP3688306A4 (en) * | 2017-09-28 | 2021-06-02 | Geoffrey Peter | Multi-power source wind turbines |
DE102018100227A1 (en) * | 2018-01-08 | 2019-07-11 | GAT Gesellschaft für Antriebstechnik mbH | Grounding grinding unit |
US11464101B1 (en) * | 2018-10-22 | 2022-10-04 | Delta T, Llc | Conductive brush for protecting a motor shaft bearing |
WO2020194191A1 (en) * | 2019-03-25 | 2020-10-01 | Troy Lance Timm | Grounding device |
DE102019117948B3 (en) * | 2019-07-03 | 2020-06-18 | Dr. Ing. H.C. F. Porsche Aktiengesellschaft | Electrical machine |
CN112751443A (en) * | 2019-10-31 | 2021-05-04 | 中车株洲电力机车研究所有限公司 | Motor shaft voltage test structure |
JP7250337B2 (en) * | 2019-11-25 | 2023-04-03 | トライス株式会社 | METAL-GRAPHITIC EARTH BRUSH MAINLY COMPOUNDED BY SILVER AND METHOD FOR MANUFACTURING THE SAME |
DE102020212589A1 (en) * | 2020-10-06 | 2022-04-07 | Zf Friedrichshafen Ag | Shaft grounding assembly, gearbox, and electric final drive |
DE102020212588A1 (en) * | 2020-10-06 | 2022-04-07 | Zf Friedrichshafen Ag | Transmission for a motor vehicle, and electric axle drive |
US11735982B2 (en) | 2021-03-18 | 2023-08-22 | General Electric Company | Bearing current mitigation for an electric machine embedded in a gas turbine engine |
DE102021113901A1 (en) * | 2021-05-28 | 2022-12-01 | Carl Freudenberg Kg | Arrangement for producing an electrically conductive connection between a first machine element and a second machine element |
DE102021209010A1 (en) * | 2021-08-17 | 2023-02-23 | Magna powertrain gmbh & co kg | Electrical machine comprising an ionizer |
CN113708543B (en) * | 2021-08-18 | 2022-05-27 | 华能通辽风力发电有限公司 | Electric generator |
EP4210203A1 (en) * | 2022-01-08 | 2023-07-12 | General Electric Renovables España S.L. | Electrical machines and methods to mitigate bearing currents |
FR3132807B1 (en) * | 2022-02-17 | 2023-12-29 | Skf Svenska Kullagerfab Ab | Electric machine with a conductive sleeve |
Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH04368446A (en) | 1991-06-18 | 1992-12-21 | Fuji Electric Co Ltd | Grounding device for shaft of electric rotating machine |
WO1997001200A1 (en) | 1995-06-23 | 1997-01-09 | Boyanton Hugh E | Motor shaft discharge device |
US5661356A (en) * | 1993-10-22 | 1997-08-26 | Fisher; Rodney R. | Motor shaft discharge device |
EP1523086A1 (en) | 2003-10-06 | 2005-04-13 | Illinois Tool Works Inc. | Grounding brush for mitigating electrical current on motor shafts |
JP2005151749A (en) * | 2003-11-18 | 2005-06-09 | Ntn Corp | Lightning protection device of wind turbine generator bearing and bearing of the device |
Family Cites Families (24)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3873835A (en) * | 1973-11-02 | 1975-03-25 | Vladimir Ignatjev | Ionizer |
US4197970A (en) * | 1978-03-08 | 1980-04-15 | James River Graphics Inc. | Electrostatic drive system |
JPS5583199A (en) * | 1978-12-20 | 1980-06-23 | Olympus Optical Co | Static eliminator |
US4281328A (en) * | 1980-01-28 | 1981-07-28 | General Dynamics, Pomona Division | Slip ring assembly |
US4398113A (en) * | 1980-12-15 | 1983-08-09 | Litton Systems, Inc. | Fiber brush slip ring assembly |
DE3364660D1 (en) * | 1982-05-06 | 1986-09-04 | Lucas Ind Plc | Small diameter slip ring assemblies and their production |
US4494166A (en) | 1982-09-21 | 1985-01-15 | Xerox Corporation | Printing machine with static elimination system |
JPH0722037B2 (en) | 1988-12-21 | 1995-03-08 | シシド静電気株式会社 | Static eliminator |
US4994861A (en) | 1989-06-30 | 1991-02-19 | International Business Machines Corporation | Printing machine with charge neutralizing system |
US5139862A (en) | 1989-11-17 | 1992-08-18 | Xerox Corporation | Pultruded electronic device |
US5354607A (en) | 1990-04-16 | 1994-10-11 | Xerox Corporation | Fibrillated pultruded electronic components and static eliminator devices |
CA2037801C (en) | 1990-04-16 | 2001-04-24 | Thomas E. Orlowski | Fibrillated pultruded electrical component |
JPH0636887A (en) | 1992-07-15 | 1994-02-10 | Ricoh Co Ltd | Electrophotographic device |
JPH06199010A (en) | 1992-12-28 | 1994-07-19 | Canon Inc | Charge eliminating brush for image forming apparatus |
JPH1129237A (en) | 1997-07-09 | 1999-02-02 | Brother Ind Ltd | Sheet body discharging device |
CN2391373Y (en) * | 1999-09-10 | 2000-08-09 | 上海富敏微电机厂 | Micro-motor inputting terminal |
US6517357B1 (en) | 2000-11-22 | 2003-02-11 | Athan Corporation | Slip ring and brush assembly for use in a video recorder |
JP2002218697A (en) * | 2001-01-22 | 2002-08-02 | Nippon Soken Inc | Brush motor |
US7071589B2 (en) | 2001-11-06 | 2006-07-04 | Precor Incorporated | Method and system for reducing bearing fluting in electromechanical machine |
US8199453B2 (en) * | 2003-03-17 | 2012-06-12 | Illinois Tool Works Inc. | Shaft current control brush ring assembly |
US7136271B2 (en) | 2003-03-17 | 2006-11-14 | Illinois Tool Works Inc | Static charge neutralizing assembly for use on rollers and shafts |
CN101151780B (en) * | 2005-04-20 | 2011-06-29 | 伊利诺斯器械工程公司 | Shaft current control brush ring assembly |
US7521827B2 (en) * | 2005-06-25 | 2009-04-21 | Isotech Of Illinois, Inc. | Motor ground seal |
US7528513B2 (en) | 2005-08-17 | 2009-05-05 | Illinois Tool Works Inc. | Shaft current control brush assembly with drainage |
-
2008
- 2008-04-07 US US12/098,573 patent/US8189317B2/en active Active
- 2008-04-10 JP JP2010506384A patent/JP5281077B2/en active Active
- 2008-04-10 EP EP08745427.8A patent/EP2137805B1/en active Active
- 2008-04-10 CN CN2008800129797A patent/CN101682234B/en active Active
- 2008-04-10 ES ES08745427.8T patent/ES2441962T3/en active Active
- 2008-04-10 WO PCT/US2008/059816 patent/WO2008130851A1/en active Application Filing
Patent Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH04368446A (en) | 1991-06-18 | 1992-12-21 | Fuji Electric Co Ltd | Grounding device for shaft of electric rotating machine |
US5661356A (en) * | 1993-10-22 | 1997-08-26 | Fisher; Rodney R. | Motor shaft discharge device |
WO1997001200A1 (en) | 1995-06-23 | 1997-01-09 | Boyanton Hugh E | Motor shaft discharge device |
EP1523086A1 (en) | 2003-10-06 | 2005-04-13 | Illinois Tool Works Inc. | Grounding brush for mitigating electrical current on motor shafts |
JP2005151749A (en) * | 2003-11-18 | 2005-06-09 | Ntn Corp | Lightning protection device of wind turbine generator bearing and bearing of the device |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US8963398B2 (en) | 2011-10-28 | 2015-02-24 | Illinois Tool Works Inc. | Current control brush assembly |
US10158274B2 (en) | 2015-05-01 | 2018-12-18 | Meidensha Corporation | Rotary machine |
DE102020215641A1 (en) | 2020-12-10 | 2022-06-15 | Zf Friedrichshafen Ag | Process for manufacturing a running surface for a sliding contact on a shaft |
Also Published As
Publication number | Publication date |
---|---|
CN101682234B (en) | 2013-08-14 |
JP5281077B2 (en) | 2013-09-04 |
CN101682234A (en) | 2010-03-24 |
EP2137805A1 (en) | 2009-12-30 |
US20080258576A1 (en) | 2008-10-23 |
US8189317B2 (en) | 2012-05-29 |
ES2441962T3 (en) | 2014-02-07 |
EP2137805B1 (en) | 2013-10-09 |
JP2010525787A (en) | 2010-07-22 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US8189317B2 (en) | Grounding brush system for mitigating electrical current on rotating shafts | |
EP1872463B1 (en) | Shaft current control brush ring assembly | |
EP1755207B1 (en) | Shaft current control brush assembly with drainage | |
EP1523086B1 (en) | Grounding brush for mitigating electrical current on motor shafts | |
US7339777B2 (en) | Grounding system for a rotating shaft | |
JP4778039B2 (en) | Axial current control brush ring assembly | |
US20190081538A1 (en) | Methods and apparatus to mitigate electrical voltage on a rotating shaft | |
JP5180257B2 (en) | Static charge neutralization assembly for use on rollers and shafts | |
TW202220313A (en) | Systems and methods to mitigate electrical voltage on a rotating shaft in oil | |
CN100536285C (en) | Grounding brush for relieving current on motor shaft | |
CN112186975B (en) | Motor shaft current eliminating structure and motor | |
CN100431226C (en) | Shaft current control brush assembly with drainage |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
WWE | Wipo information: entry into national phase |
Ref document number: 200880012979.7 Country of ref document: CN |
|
121 | Ep: the epo has been informed by wipo that ep was designated in this application |
Ref document number: 08745427 Country of ref document: EP Kind code of ref document: A1 |
|
WWE | Wipo information: entry into national phase |
Ref document number: 2008745427 Country of ref document: EP |
|
WWE | Wipo information: entry into national phase |
Ref document number: 2010506384 Country of ref document: JP |
|
NENP | Non-entry into the national phase |
Ref country code: DE |