US20170077663A1 - Current Diverter Ring - Google Patents
Current Diverter Ring Download PDFInfo
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- US20170077663A1 US20170077663A1 US15/351,213 US201615351213A US2017077663A1 US 20170077663 A1 US20170077663 A1 US 20170077663A1 US 201615351213 A US201615351213 A US 201615351213A US 2017077663 A1 US2017077663 A1 US 2017077663A1
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- Prior art keywords
- ring
- radial
- current diverter
- cdr
- conductive
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Images
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01R—ELECTRICALLY-CONDUCTIVE CONNECTIONS; STRUCTURAL ASSOCIATIONS OF A PLURALITY OF MUTUALLY-INSULATED ELECTRICAL CONNECTING ELEMENTS; COUPLING DEVICES; CURRENT COLLECTORS
- H01R39/00—Rotary current collectors, distributors or interrupters
- H01R39/02—Details for dynamo electric machines
- H01R39/08—Slip-rings
- H01R39/12—Slip-rings using bearing or shaft surface as contact surface
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01R—ELECTRICALLY-CONDUCTIVE CONNECTIONS; STRUCTURAL ASSOCIATIONS OF A PLURALITY OF MUTUALLY-INSULATED ELECTRICAL CONNECTING ELEMENTS; COUPLING DEVICES; CURRENT COLLECTORS
- H01R39/00—Rotary current collectors, distributors or interrupters
- H01R39/02—Details for dynamo electric machines
- H01R39/08—Slip-rings
- H01R39/10—Slip-rings other than with external cylindrical contact surface, e.g. flat slip-rings
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01R—ELECTRICALLY-CONDUCTIVE CONNECTIONS; STRUCTURAL ASSOCIATIONS OF A PLURALITY OF MUTUALLY-INSULATED ELECTRICAL CONNECTING ELEMENTS; COUPLING DEVICES; CURRENT COLLECTORS
- H01R39/00—Rotary current collectors, distributors or interrupters
- H01R39/64—Devices for uninterrupted current collection
-
- 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
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02K—DYNAMO-ELECTRIC MACHINES
- H02K5/00—Casings; Enclosures; Supports
- H02K5/04—Casings or enclosures characterised by the shape, form or construction thereof
- H02K5/16—Means for supporting bearings, e.g. insulating supports or means for fitting bearings in the bearing-shields
- H02K5/173—Means for supporting bearings, e.g. insulating supports or means for fitting bearings in the bearing-shields using bearings with rolling contact, e.g. ball bearings
- H02K5/1732—Means for supporting bearings, e.g. insulating supports or means for fitting bearings in the bearing-shields using bearings with rolling contact, e.g. ball bearings radially supporting the rotary shaft at both ends of the rotor
Definitions
- the present invention relates to an electrical charge dissipating device, and more particularly to a current diverter RingTM for directing electrostatic charge to ground, which electrostatic charge is created through the use of rotating equipment.
- VFDs variable frequency drives
- VFDs regulate the speed of a motor by converting sinusoidal line alternating current (AC) voltage to direct current (DC) voltage, then back to a pulse width modulated (PWM) AC voltage of variable frequency.
- the switching frequency of these pulses ranges from 1 kHz up to 20 kHz and is referred to as the “carrier frequency.”
- Insulated bearings provide an internal solution by eliminating the path to ground through the bearing for current to flow.
- installing insulated bearings does not eliminate the shaft voltage, which will continue to find the lowest impedance path to ground.
- insulated bearings are not effective if the impedance path is through the driven load. Therefore, the prior art does not teach an internal, low-wearing method or apparatus to efficaciously ground shaft voltage and avoid electric discharge machining of bearings leading to premature bearing failure.
- An objective of the current diverter ring is to provide an improvement to seals or bearing isolators to prevent leakage of lubricant and entry of contaminants by encompassing the stator within the rotor to create an axially directed interface at the radial extremity of the rotor. It is also an objective of the current diverter ring to disclose and claim an apparatus for rotating equipment that conducts and transmits and directs accumulated bearing current to ground.
- Conductive segments may be positioned within the current diverter ring. These conductive segments may be constructed of metallic or non-metallic solids, machined or molded. Although any type of material compatible with operating conditions and metallurgy may be selected, bronze, gold, carbon, or aluminum are believed to be preferred materials because of increased conductivity, strength, corrosion and wear resistance.
- bearing isolator having a rotor and stator manufactured from bronze has improved electrical charge dissipation qualities.
- the preferred bronze metallurgy is that meeting specification 932 (also referred to as 932000 or “bearing bronze”). This bronze is preferred for bearings and bearing isolators because it has excellent load capacity and antifriction qualities. This bearing bronze alloy also has good machining characteristics and resists many chemicals.
- the specified bronze offers increased shaft voltage collection properties comparable to the ubiquitous lightning rod due to the relatively low electrical resistivity (85.9 ohms-cmil/ft @ 68 F or 14.29 microhm-cm @ 20 C) and high electrical conductivity (12% IACS @ 68 F or 0.07 MegaSiemens/cm @ 20 C) of the material selected.
- Previous tests of a combination bearing isolator with a concentric current diverter ring fixedly mounted within the bearing isolator have shown substantial reduction in shaft voltage and attendant electrostatic discharge machining.
- Direct seating between the current diverter ring and the bearing isolator improves the conduction to ground over a simple housing in combination with a conduction member as taught by the prior art. Those practiced in the arts will understand that this improvement requires the electric motor base to be grounded, as is the norm.
- FIG. 1 is a perspective view of one embodiment of an electric motor with which the current diverter ring may be employed.
- FIG. 2 is a perspective cross-sectional view of a bearing isolator wherein a portion of the stator is fashioned as a current diverter ring.
- FIG. 3 is a cross-sectional view of a bearing isolator configured to accept a current diverter ring within the stator portion of the bearing isolator.
- FIG. 4 is a perspective view of the first embodiment of the current diverter ring.
- FIG. 5 is an axial view of the first embodiment of the current diverter ring.
- FIG. 6 is a cross-sectional view of the first embodiment of the current diverter ring.
- FIG. 7 is a perspective, exploded view of a second embodiment of the current diverter ring.
- FIG. 8A is a perspective view of a second embodiment of the current diverter ring assembled.
- FIG. 8B is a perspective view of a second embodiment of the current diverter ring assembled with mounting clips.
- FIG. 9 is a detailed perspective view of one embodiment of an inner body for use with the second embodiment of the current diverter ring.
- FIG. 10A is an axial view of one embodiment of an inner body for use with the second embodiment of the current diverter ring.
- FIG. 10B is a cross-sectional view of one embodiment of an inner body for use with the second embodiment of the current diverter ring.
- FIG. 11 is a cross-sectional view of one embodiment of an inner body for use with the second embodiment of the current diverter ring with conductive fibers positioned therein.
- FIG. 12 is a detailed perspective view of one embodiment of an outer body for use with the second embodiment of the current diverter ring.
- FIG. 13A is an axial view of one embodiment of an outer body for use with the second embodiment of the current diverter ring.
- FIG. 13B is a cross-sectional view of one embodiment of an outer body for use with the second embodiment of the current diverter ring.
- FIG. 14A is an axial view of the second embodiment of the current diverter ring assembled.
- FIG. 14B is a cross-sectional view of the second embodiment of the current diverter ring assembled.
- FIG. 15A is a perspective view of a third embodiment of the current diverter ring.
- FIG. 15B is an axial cross section view of the third embodiment of the current diverter ring.
- FIG. 15C is a perspective view of one embodiment of a conductive assembly that may be used with certain embodiments of the CDR.
- FIG. 16A is a perspective view of a fourth embodiment of the current diverter ring.
- FIG. 16B is a perspective, exploded view of the fourth embodiment of the current diverter ring.
- FIG. 16C is an axial cross section view of the fourth embodiment of the current diverter ring.
- FIG. 16D is a detailed cross section view of the fourth embodiment of the current diverter ring.
- FIG. 17A is a perspective view of a fifth embodiment of the current diverter ring having a split design.
- FIG. 17B is a perspective, exploded view of the fifth embodiment of the current diverter ring.
- FIG. 17C is an axial cross section view of the fifth embodiment of the current diverter ring.
- FIG. 17D is a detailed cross section view of the fifth embodiment of the current diverter ring.
- FIG. 18A is a perspective view of one embodiment of an adaptable current diverter ring.
- FIG. 18B is an axial cross section view of one embodiment of an adaptable current diverter ring.
- CDR 40 radial CDR 80
- multi-ring CDR 100 radial CDR 80
- adaptable CDR 160 may be used interchangeably when referring to generalities of configuration with a bearing isolator 10 , methods and/or materials of construction, and/or other general features.
- FIG. 1 One embodiment of an equipment housing 16 with which the CDR® 40 may be used is shown in FIG. 1 .
- the CDR 40 may be press-fit into an aperture in the equipment housing 16 , or it may be secured to the exterior of the equipment housing 16 using straps 70 and fasteners 72 as described in detail below and as shown in FIG. 1 .
- the CDR 40 may also be secured to an equipment housing 12 via other structures and/or methods, such as chemical adhesion, welding, rivets, or any other structure and/or method suitable for the particular application.
- the CDR 40 may also be configured to be engaged with a bearing isolator 10 , or integrally formed with a bearing isolator 10 , as described in detail below.
- FIG. 2 illustrates a perspective view of one embodiment of a bearing isolator 10 configured to discharge electrical impulses from the shaft 14 through the equipment housing 16 .
- the bearing isolator 10 as shown in FIG. 2 may be mounted to a rotatable shaft 10 on either one or both sides of the equipment housing 16 .
- the bearing isolator 10 may be flange-mounted, press-fit (as shown in FIG. 2 ), or attached to the equipment housing 16 using any other method and/or structure suitable for the particular application, as was described above for the CDR 40 .
- set screws (not shown) or other structures and/or methods may be used to mount either the stator 20 to the equipment housing 16 or the rotor 30 to the shaft 14 .
- the shaft 14 is stationary and the equipment housing 16 or other structure to which the bearing isolator 10 is mounted may rotate.
- the CDR 40 and/or bearing isolator 10 may be mounted such that either the CDR 40 and/or bearing isolator 10 are allowed to float in one or more directions.
- a portion of the bearing isolator 10 is positioned in an enclosure.
- the enclosure is fashioned as two opposing plates with main apertures therein, through which main apertures the shaft passes 14 .
- the interior of the enclosure is fashioned such that the bearing isolator 10 and/or CDR 40 is positioned within a truncated circle (i.e., pill-shaped) recess on the interior of the enclosure.
- the contact points between the bearing isolator 10 and/or CDR 40 and the enclosure may be formed with a low friction substance, such as Teflon®, affixed thereto.
- FIG. 3 A more detailed cross-sectional view of one embodiment of a bearing isolator 10 with which the CDR 40 may be used is shown in FIG. 3 .
- the bearing isolator 10 shown in FIGS. 2 and 3 includes a stator 20 and a rotor 30 , and is commonly referred to as a labyrinth seal.
- labyrinth seals are well known to those skilled in the art and include those disclosed in U.S. Pat. Nos. 7,396,017; 7,090,403; 6,419,233; 6,234,489; 6,182,972; and 5,951,020; and U.S. Pat. App. Pub. No. 2007/0138748, all of which are incorporated by reference herein in their entireties.
- the stator 20 may be generally comprised of a stator main body 22 and various axial and/or radial projections extending therefrom and/or various axial and/or radial grooves configured therein, which are described in more detail below.
- the stator 20 is fixedly mounted to an equipment housing 16 with an O-ring 18 forming a seal therebetween.
- the rotor 30 may be generally comprised of a rotor main body 32 and various axial and/or radial projections extending therefrom and/or various axial and/or radial grooves configured therein, which are described in more detail below.
- one stator axial projection 26 cooperates with a rotor axial groove 39
- one rotor axial projection 36 cooperates with a stator axial groove 29 to form a labyrinth passage between the interior portion of the bearing isolator 10 and the external environment.
- the rotor 30 may be fixedly mounted to a shaft 14 and rotatable therewith.
- An O-ring 18 may be used to form a seal therebetween.
- a sealing member 17 may be positioned between the stator 20 and rotor 30 on an interior interface therebetween to aide in prevention of contaminants entering the interior of the bearing isolator 10 from the external environment while simultaneously aiding in retention of lubricants in the interior of the bearing isolator 10 .
- one stator radial projection 28 provides an exterior groove in the stator 20 for collection of contaminants.
- a first axial interface gap 34 a may be formed between the radially exterior surface of a stator radial projection 28 and the radially interior surface of a rotor radial projection 38 .
- a first radial interface gap 34 b may be formed between the axially exterior surface of a stator axial projection 26 and the axially interior surface of a rotor axial groove 39 .
- a rotor axial projection 36 formed with a rotor radial projection 38 may be configured to fit within a stator axial groove 29 to provide another axial interface gap between the stator 20 and the rotor 30 .
- one rotor radial projection 38 (adjacent the rotor axial exterior surface 33 ) extends radially beyond the major diameter of the stator axial projection 26 . This permits the rotor 30 to encompass the stator axial projection 26 . As is fully described in U.S. Pat. No. 6,419,233, which is incorporated by reference herein in its entirety, this radial extension is a key design feature of the bearing isolator 10 shown herein.
- the axial orientation of the first axial interface gap 34 a controls entrance of contaminants into the bearing isolator 10 .
- the opening of the first axial interface gap 34 a faces rearward, toward the equipment housing 16 and away from the contaminant stream.
- the contaminant or cooling stream will normally be directed along the axis of the shaft 14 and toward the equipment housing 16 .
- the bearing isolator 10 may include at least one conductive segment 46 positioned within the stator 20 .
- the stator 20 may be configured with a conductive segment retention chamber adjacent the bearing 12 , in which conductive segment retention chamber the conductive segment 46 may be positioned and secured such that the conductive segment 46 is in contact with the shaft 14 .
- the conductive segment 46 serves to dissipate those charges through the bearing isolator 10 and to the equipment housing 16 .
- the specific size and configuration of the conductive segment retention chamber will depend on the application of the bearing isolator 10 and the type and size of each conductive segment 46 . Accordingly, the size and configuration of the conductive segment annular channel is in no way limiting.
- a preferred configuration of the conductive segment retention chamber is a radial channel 52 , such as those described for the CDR 40 embodiment shown in FIGS. 7-14 or as described for the radial CDR 80 , shown in FIGS. 15A-15C .
- the bearing isolator 10 is formed with a receptor groove 24 .
- the receptor groove 24 may be fashioned on the inboard side of the bearing isolator 10 adjacent the shaft 14 , as best shown in FIG. 3 .
- the receptor groove 24 facilitates the placement of a CDR 40 within the bearing isolator 10 .
- other structures may be positioned within the receptor groove 24 depending on the specific application of the bearing isolator 10 .
- the bearing isolator 10 in FIGS. 2 and 3 includes a plurality of radial and axial interface passages between the stator 20 and the rotor 30 resulting from the cooperation of the stator projections 26 , 28 with rotor grooves 39 and the cooperation of rotor projections 36 , 38 with stator grooves 29 .
- the bearing isolator 10 as disclosed herein may be used with any configuration stator 20 and/or rotor 30 wherein the stator 20 may be configured with a conductive segment retention chamber for retaining at least one conductive segment 46 therein or a receptor groove 24 as described in detail below.
- a first embodiment of a current diverter ring (CDR) 40 is shown in perspective in FIG. 4 , and FIG. 5 provides an axial view thereof.
- the CDR 40 may be used with any rotating equipment that has a tendency to accumulate an electrical charge on a portion thereof, such as electrical motors, gearboxes, bearings, or any other such equipment.
- the first embodiment of the CDR 40 is designed to be positioned between an equipment housing 16 and a shaft 14 protruding from the equipment housing 16 and rotatable with respect thereto.
- the CDR 40 is comprised of a CDR body 41 , which may be fixedly mounted to the equipment housing 16 .
- a first wall 43 and a second wall 44 extend from the CDR body 41 and define an annular channel 42 .
- At least one conductive segment 46 is fixedly retained in the annular channel 42 so that the conductive segment 46 is in contact with the shaft 14 so as to create a low impedance path from the shaft 14 to the equipment housing 16 .
- FIG. 6 A cross-sectional view of the first embodiment of the CDR 40 is shown in FIG. 6 .
- the axial thickness of the first wall 43 is less than that of the second wall 44 .
- the conductive segment 46 is retained within the annular channel 42 by first positioning the conductive segment 46 within the annular channel 42 and then deforming the first wall 43 to reduce the clearance between the distal ends of the first and second walls 43 , 44 . Deforming the first wall 43 in this manner retains the conductive segment 46 within the annular channel 42 .
- the deformation of the first wall 43 may compress a portion of the conductive segment 46 to further secure the position of the conductive segment 46 with respect to the shaft 14 .
- the CDR radial exterior surface 45 may be configured with a slight angle in the axial dimension so that the CDR 40 may be press-fit into the equipment housing 16 .
- the angle is one degree, but may be more or less in other embodiments not pictured herein.
- the first wall 43 is positioned adjacent the bearing 12 when the CDR 40 is installed in an equipment housing 16 .
- the second wall 44 may be positioned adjacent the bearing 12 when the CDR 40 is installed in an equipment housing 16 , in which case the angle of the CDR radial exterior surface 45 would be opposite of that shown in FIG. 6 .
- the optimal dimensions/orientation of the CDR body 41 , annular channel 42 , first wall 43 , second wall 44 , and CDR radial exterior surface 45 will vary depending on the specific application of the CDR 40 and are therefore in no way limiting to the scope of the CDR 40 .
- a CDR 40 with a conductive segment retention chamber configured as an annular channel is not preferred. Performance and manufacturing considerations are among the reasons such a configuration is not preferred. Instead, the other embodiments of the CDR disclosed herein, which do not have an annular channel 42 and the attending difficulties, are preferred.
- the CDR 40 is mounted to the equipment housing 16 using mounting apertures 54 , straps 70 , and fasteners 72 fashioned in either the CDR 40 or equipment housing 16 .
- the CDR 40 may be mounted to the equipment housing 16 by any method using any structure suitable for the particular application without departing from the spirit and scope of the CDR 40 .
- three conductive segments 46 are positioned within the annular channel 42 .
- the optimal number of conductive segments 46 and the size and/or shape of each conductive segment 46 will vary depending on the application of the CDR 40 , and is therefore in no way limiting.
- the optimal total length of all conductive segments 46 and the total surface area of the conductive segments 46 that are in contact with the shaft 14 will vary from one application to the next, and is therefore in no way limiting to the scope of the CDR 40 or of a bearing isolator 10 configured with conductive segments 46 (such as the bearing isolator shown in FIGS. 2 and 3 ).
- the CDR 40 may be sized to be engaged with a bearing isolator 10 having a receptor groove 24 , such as the bearing isolator 40 shown in FIGS. 2 and 3 .
- FIGS. 2 and 3 shown one embodiment of a bearing isolator 10 fashioned to engage a CDR 40 .
- the receptor groove 24 may be formed as a recess in the stator 20 that is sized and shaped to accept a CDR 40 similar to the one shown in FIGS. 4-6 , or other embodiments of the CDR 40 disclosed herein.
- the CDR 40 may be press-fit into the receptor groove 24 , or it may be affixed to the stator 20 by any other method or structure that is operable to fixedly mount the CDR 40 to the stator 20 , including but not limited to set screws, welding, etc.
- the CDR radial exterior surface 45 abuts and contacts the interior surface of the receptor groove 24 .
- the conductive segment 46 may be constructed of carbon, which is conductive and naturally lubricious.
- the conductive segment 46 is constructed of a carbon mesh manufactured by Chesterton and designated 477-1.
- the conductive segment 46 has no coating on the exterior of the carbon mesh.
- the conductive segments 46 Shortly after the shaft 14 has been rotating with respect to the conductive segments 46 , certain embodiments of the conductive segments 46 will wear and abrade from the surface of the shaft 14 so that friction between the conductive segments 46 and the shaft 14 is minimized.
- the conductive segments 46 may be fibrous, solid, or other material without limitation.
- the impedance from the shaft 14 to the equipment housing 16 is in the range of 0.2 to 10 ohms to ensure that electrical charges that have accumulated on the shaft 14 are discharged through the equipment housing 16 and to the base of the motor (not shown) rather than through the bearing(s) 12 .
- the impedance from the shaft 14 to the equipment housing 16 may be decreased by ensuring the fit between the bearing isolator 10 and equipment housing 16 , bearing isolator 10 and CDR 40 , and/or CDR 40 and equipment housing 16 has a very small tolerance. Accordingly, the smaller the gap between the bearing isolator 10 and equipment housing 16 , bearing isolator 10 and CDR 40 , and/or CDR 40 and equipment housing 16 , the lower the impedance from the shaft 14 to the equipment housing 16 .
- conductive filaments may be affixed to either the CDR 40 or bearing isolator 10 or embedded in conductive segments 46 affixed to either the CDR 40 or bearing isolator 10 .
- Such filaments may be constructed of aluminum, copper, gold, carbon, conductive polymers, conductive elastomers, or any other conductive material possessing the proper conductivity for the specific application. Any material that is sufficiently lubricious and with sufficiently low impedance may be used for the conductive segment(s) 46 in the CDR 40 and/or bearing isolator 10 .
- the CDR 40 is affixed to the shaft 14 and rotates therewith.
- the first and second walls 43 , 44 of the CDR 40 extend from the shaft 14 , and the CDR main body 41 is adjacent the shaft 14 .
- the centrifugal force of the rotation of the shaft 14 causes the conductive segments 46 and/or conductive filaments to expand radially as the shaft 14 rotates.
- This expansion allows the conductive segments 46 and/or filaments to make contact with the equipment housing 16 even if grease or other contaminants and/or lubricants (which increase impedance and therefore decrease the ability of the CDR 40 to dissipate electrical charges from the shaft 14 to the equipment housing 16 ) have collected in an area between the CDR 40 and the equipment housing 16 .
- a conductive sleeve may be positioned on the shaft 14 .
- This embodiment is especially useful for a shaft 14 having a worn or uneven surface that would otherwise lead to excessive wear of the conductive segments 46 .
- the conductive sleeve may be constructed of any electrically conductive material that is suitable for the particular application, and the conductive sleeve (not shown) may also be fashioned with a smooth radial exterior surface. The conductive sleeve (not shown) would then serve to conductive electrical charges from the shaft 14 to the conductive segments 46 in either the CDR 40 or a bearing isolator 10 .
- conductive filaments or wires are inserted into the conductive segments 46 .
- These conductive filaments or wires may be sacrificial and fill in depressions or other asperities of the surface of the shaft 14 .
- conductive screws made of suitable conductive materials may be inserted into the conductive segments 46 .
- spring-loaded solid conductive cylinders may be positioned within the CDR 40 and/or bearing isolator 10 in the radial direction so as to contact the radial exterior surface of the shaft 14 .
- the CDR 40 shown in FIGS. 4-6 is not the preferred embodiment of the CDR 40 , as previously mentioned. Among other considerations, performance and manufacturing difficulties with this design dictate that other embodiments of the CDR 40 are more desirable. Particularly, the two-piece CDR 40 shown in FIGS. 7-14 and described in detail below and the radial CDR 80 shown in FIGS. 15A, 15B result in both of those embodiments being superior to that shown in FIGS. 4-6 .
- FIGS. 7-14 A second embodiment of a CDR 40 is shown in FIGS. 7-14 .
- the CDR is formed from the engagement of an inner body 50 with an outer body 60 , which are shown disengaged but in relation to one another in FIG. 7 .
- the inner body 50 and outer body 60 in the second embodiment of the CDR 40 engage one another in a snapping, interference-type fit, which is described in detail below.
- FIG. 9 A perspective view of an inner body 50 , which may be generally ring shaped, is shown in FIG. 9 .
- the inner body 50 may include at least one radial channel 52 fashioned in an exterior face of the inner body 50 , which includes a main aperture 58 through which a shaft 14 may be positioned.
- the embodiment pictured in FIG. 9 includes three radial channels 52 , but other embodiments may have a greater or lesser number of radial channels 52 , and therefore the number of radial channels in no way limits the scope of the CDR 40 .
- Each radial channel 52 may be formed with a catch 52 a therein to more adequately secure certain types of conductive segments 46 .
- a catch 52 a will be most advantageous with conductive segments 46 made of a deformable or semi-deformable material (as depicted in FIG. 14B ), but a catch 52 a may be used with conductive segments 46 constructed of materials having different mechanical properties.
- the radial channels 52 as shown are configured to open toward a shaft 14 positioned in the main aperture 58 .
- the inner body 50 may be formed with a ridge 56 on the radial exterior surface thereof. The ridge 56 may be configured to engage the annular groove 64 formed in the outer body 60 as described in detail below.
- the inner body 50 may be formed with one or more mounting apertures 54 therein.
- the embodiment shown in FIGS. 8-11 is formed with three mounting apertures 54 .
- Mounting apertures 54 may be used to secure the CDR 40 to an equipment housing 16 or other structure as shown in FIG. 1 .
- a strap 70 or clip may be secured to the CDR 40 using a fastener 72 , such as a screw or rivet, engaged with a mounting aperture 54 , as shown in FIGS. 1 and 8B .
- the presence or absence of mounting apertures 54 will largely depend on the mounting method of the CDR 40 .
- the inner body 50 does not include any mounting apertures 54 . It is contemplated that such embodiments will be optimal for use within a bearing isolator 10 and/or a CDR 40 that will be press fit into an equipment housing 16 or other structure.
- FIG. 12 A perspective view of an outer body 60 , which also may be generally ring shaped, is shown in FIG. 12 .
- the outer body 60 may be formed with a base 62 having an annular groove 64 formed on the radial interior surface thereof.
- the annular groove 64 may be defined by a first annular shoulder 64 a and a second annular shoulder 65 b .
- a radial projection 66 may extend radially inward from the base 62 adjacent either the first and/or second shoulder 65 a , 65 b .
- the radial projection 66 is positioned adjacent the first annular shoulder 65 a and includes a main aperture 68 therein, through which a shaft 14 may be positioned.
- the annular groove 64 may be configured such that the ridge 56 formed in the inner body 50 engages the annular groove 64 so as to substantially fix the axial position of the inner body 50 with respect to the outer body 60 .
- the ridge 56 may be slanted or tapered so that upon forced insertion of the inner body 50 in the outer body 60 , the ridge 56 slides past the second annular shoulder 65 b and into the annular groove 64 to axially secure the inner body 50 and the outer body 60 .
- the engagement between the ridge 56 and the annular groove 64 thereafter resists separation or dissociation of the inner and outer bodies 50 , 60 .
- the ridge 56 is not limited to a tapered configuration.
- the ridge 56 and base 62 may also be configured so an interference fit is created upon engagement to resist separation or disassociation of the inner and outer bodies 50 , 60 .
- the inner body 50 and outer body 60 may be configured so that the interior periphery of the radial projection 66 has the same diameter as the interior periphery of the inner body 50 so that both the inner and outer bodies 50 , 60 have the same clearance from a shaft 14 when installed. It is contemplated that in most applications the CDR 40 will be installed so that the surface shown in FIG. 14A is axially exterior to the equipment housing 16 or other structure. However, if the CDR 40 is engaged with a bearing isolator 10 , the CDR 40 may be oriented such that the surface shown in FIG. 14A is facing toward the interior of the equipment housing 16 or other structure to which the bearing isolator 10 is mounted.
- conductive segments 46 may be positioned in each radial channel 52 . It is contemplated that the radial channels 52 will be fashioned in the axial surface of the inner body 50 that is positioned adjacent the radial projection 66 of the outer body 60 when the CDR 40 is assembled, as shown in FIGS. 14A and 14B . This orientation secures the axial position of the conductive segments 46 . As mentioned previously, a CDR 40 employing radial channels 52 for retention of conductive segments 52 is preferred as compared to a CDR 40 having an annular channel 42 . Typically, but depending on the materials of construction, the conductive segments 46 are sized so as to extend past the minor diameter of the inner body 50 into the main aperture 58 to contact the shaft 14 . The radial channels 52 are sized so as to not intersect the outer periphery of the inner body 50 . This prevents the conductive segment 46 from contacting the annular groove 64 of the outer body 60 .
- the bearing isolator 10 and CDR 40 may be constructed from any machinable metal, such as stainless steel, bronze, aluminum, gold, copper, and combinations thereof, or other material having low impedance.
- the CDR 40 or bearing isolator 10 may be flange-mounted, press-fit, or attached to the equipment housing 16 by any other structure or method, such as through a plurality of straps 70 and fasteners 72 .
- performance of the bearing isolator 10 may be improved by eliminating the O-rings 18 and their companion grooves fashioned in the stator 20 and the rotor 30 , as shown in FIGS. 2 and 3 .
- the high-impedance nature of material used to construct the O-ring 18 may impede conductivity between bearing isolator 10 and the equipment housing 16 , thereby decreasing the overall electrical charge dissipation performance of the bearing isolator 10 .
- the O-rings 18 may be constructed of a low-impedance material, they may be included in any application of the CDR 40 and/or bearing isolator 10 .
- the optimal dimensions/orientation of the CDR 40 , inner body 50 , outer body 60 , and various features thereof will vary depending on the specific application of the CDR 40 and are therefore in no way limiting to the scope of the CDR 40 .
- a radial CDR 80 is another embodiment of a CDR 40 , which is shown in FIGS. 15A, 15B as a ring-shaped structure having a main aperture 88 in the center thereof.
- the CDR 40 may be mounted to rotational equipment through any structure and/or method without limitation.
- the embodiment of the radial CDR 80 shown in FIGS. 15A and 15B includes three straps 70 affixed to the radial CDR 80 via fasteners 72 . Other fasteners 72 may be used to secure the straps 70 to the rotational equipment, thereby securing the radial CDR 80 to the rotational equipment.
- the radial exterior surface 85 a of the radial CDR 80 is press-fit into the rotational equipment housing 16 .
- the mounting method for the radial CDR is in no way limiting to its scope.
- the embodiment of the radial CDR 80 shown herein includes three radial channels 82 extending from the radial exterior surface 85 a to the radial interior surface 85 b .
- Each radial channel 82 may include a radial channel shelf 83 , which is best shown in FIG. 15B .
- the radial channel shelf 83 is located adjacent the radial interior surface 85 b of the radial CDR 80 .
- a conductive assembly 86 may be configured to securely fit within the radial channel 82 .
- a conductive assembly 86 is shown in detailed in FIG. 15C .
- the conductive assembly 86 may comprise a binder 86 a that is primarily located within the radial channel 82 and a contact portion 86 b that extends radially inward from the radial channel 82 .
- the binder 86 a may be formed as any structure that retains the elements of the conductive assembly 86 , including but not limited to a chemical adhesive, structural cap or tether, or combinations thereof.
- Other types of conductive assemblies 86 may be used with the radial CDR 80 without limitation.
- the conductive assemblies 86 in the radial CDR 80 may be configured to be replaceable. That is, once the contact portion 86 b of a conductive assembly 86 has been exhausted, or the conductive assembly 86 should otherwise be replaced, the user may remove the conductive assembly 86 from the radial channel 82 and insert a new conductive assembly 86 therein.
- FIGS. 16A-16D A first embodiment of a multi-ring CDR 100 is shown in FIGS. 16A-16D .
- This embodiment of a multi-ring CDR 100 is similar to the two-piece CDR 40 described in detail above and shown in FIGS. 7-14B .
- the multi-ring CDR 100 includes a retainer 110 with which at least two rings 120 are secured.
- the retainer 110 may be substantially ring-shaped with a retainer main aperture 118 in the center thereof, which retainer main aperture 118 corresponds to each ring main aperture 128 .
- the retainer 110 may be formed with a plurality of annular grooves 112 a , 112 b , 112 c , 112 d on the radial interior surface of the retainer base 111 to provide seating surfaces for the various rings 120 .
- the embodiment of the multi-ring CDR 100 shown herein includes a total of four rings 120 and four annular grooves 112 . However, other embodiments may be a greater or smaller number of rings 120 and corresponding annular grooves 112 without limiting the scope of the multi-ring CDR 100 .
- the rings 120 may be formed with a plurality of radial channels 122 similar to those formed in the inner body 50 for the embodiment of the CDR 40 shown in FIGS. 7-14 .
- the radial channel 116 is typically formed on the interior axial surface 127 a of the ring 120 .
- a conductive segment 116 may be positioned in each radial channel 122 .
- each radial channel 122 may be formed with a catch 122 a therein to better retain the conductive segment 116 .
- a retainer wall 114 may extend radially inward from the first annular groove 112 a toward the retainer main aperture 118 , which retainer wall 114 is analogous to the radial projection 66 of the outer body 60 for the CDR 40 embodiment shown in FIGS. 7-14 .
- the retainer wall 114 is substantially perpendicular to the retainer base 111 .
- the retainer wall 114 may serve as a stop for the innermost ring 120 as shown in FIGS. 16C and 16D .
- the interior axial surface 127 a of the innermost ring 120 may abut the retainer wall 114 , thereby compressing the conductive segments 116 positioned in the radial channels 122 of the innermost ring 120 between the ring 120 and the retainer wall 114 .
- the ring radial exterior surface 125 of the innermost ring 120 may engage the first annular groove 112 a in such a manner as to secure the innermost ring 120 to the retainer 110 via an interference fit.
- the interior axial surface 127 a of the ring 120 immediately exterior to the innermost ring 120 may abut the exterior axial surface 127 b of the innermost ring 120 , thereby compressing the conductive segments 116 positioned in the radial channels 112 of that ring 120 between that ring 120 and the innermost ring 120 .
- the ring radial exterior surface 125 of the ring 120 immediately exterior to the innermost ring 120 may engage the second annular groove 112 b in such a manner as to secure that ring 120 to the retainer via an interference fit. This is shown in detail in FIGS. 16C and 16D .
- the arrangement may continue with all rings 120 engaged with the retainer 110 .
- the outermost ring 120 may be configured with a ridge 162 on the ring radial exterior surface 125 .
- This ridge 162 may be angled upward from the interior axial surface 127 a to the exterior axial surface 127 b , such that the ridge 126 engages a snap groove 113 that may be formed in the outermost annular groove 112 (which is the fourth annular groove 112 d in the embodiment shown herein).
- the outermost ring 120 may be secured to the retainer 110 , thereby securing all other rings 120 , through the engagement of the ridge 126 with the snap groove 113 .
- This is analogous to the engagement of the inner body 50 with the outer body 60 via the ridge 56 and annular groove 64 , respectively located on the inner body 50 and outer body 60 for the CDR 40 shown in FIGS. 7-14 .
- the rings 120 may be secured to the retainer 110 using fasteners, such as fasteners, as shown in FIGS. 17A-17D .
- the rings 120 in this embodiment may be comprised of two ring segments 130 , and the retainer 110 may be formed as two separate pieces.
- the interaction between the innermost split ring segments 130 and the retainer 110 is analogous to that described above for the first embodiment of the multi-ring CDR 100 .
- the interaction between adjacent split ring segments 130 and the corresponding retention of conductive segments 116 for the split multi-ring CDR 100 is analogous to that described for the first embodiment of the multi-ring CDR 100 .
- the interference fit securement mechanism may be employed alone or in combination with a plurality of fasteners 72 , or the plurality of fasteners 72 may be solely employed as a securement mechanism. If fasteners 72 are used, the ring segments 130 may be formed with apertures 132 to receive the fasteners 72 .
- a backing ring 140 may be used with certain embodiments of the CDR 40 , 80 , 100 , as shown in FIGS. 17A-17D .
- the backing ring 140 may also be formed of two distinct pieces, which pieces may be secured to one another through a plurality of corresponding alignment pin receptors 142 , fastener bores 143 , fastener receptors 144 and corresponding alignment pins 141 and fasteners 72 .
- two alignment pins 141 and corresponding alignment pin receptors 142 are positioned at the seam of the backing ring 140 to properly align the two pieces.
- Two fasteners 72 may be placed in respective fastener bores 143 so that a portion of each fastener 72 engages a respective fastener receptor 144 , thereby securing the two pieces of the backing ring 140 to one another.
- the backing ring 140 may be manufactured so that the gap between the two pieces is negligible so as to prevent ingress of contaminants to and egress of lubricants from the bearing location. To do this, first a circle may be bisected across its diameter. The two pieces, when joined, form an ellipse due to the material removed during cutting. Accordingly, the two pieces may be machined so that together they form a perfect or near perfect circle. Alignment pin receptors 142 and corresponding alignment pins 141 and/or fastener bores 143 and corresponding fasteners 72 may be used alone or in combination to secure the relative positions of the two pieces (as described above) during the machining. Relative stability of the two pieces is required to create a perfect or near perfect circle from the two pieces.
- the backing ring main aperture 148 and O-ring channel 145 may be fashioned in the backing ring 140 to the desired specifications.
- Apertures 146 may be fashioned in the backing ring 140 per the user's requirements so that the perfectly or near perfectly circular backing ring 140 may be properly centered over a shaft or other structure.
- the adaptable CDR 160 is designed so that it may be mounted to a wide variety of rotational equipment with different geometries.
- the adaptable CDR may include a plurality of radial channels 162 that extend from the radial exterior surface 165 a to the radial interior surface 165 b adjacent the main aperture 168 .
- the radial channels 162 in the adaptable CDR 160 may include a radial channel shelf 163 . Accordingly, a conductive assembly 86 may secured in each radial channel 162 .
- the adaptable CDR 160 may include a plurality of recesses 164 to better accommodate differences in the exterior of various rotational equipment.
- the adaptable CDR 160 may have a cut out 166 protruding into the main aperture 168 to facilitate installation of the adaptable CDR 160 over a shaft or other object.
- the bearing isolator 10 and/or CDR 40 employed with an equipment housing 16 creates a stable, concentric system with the rotating shaft 14 as the center point. Inserting a CDR 40 into bearing isolator 10 such as the one shown in FIGS. 2 and 3 within the equipment housing 16 forms a relatively fixed and stable spatial relationship between the conducting elements, thereby improving the collection and conduction of electrostatic discharge from the shaft 14 to ground, through the conducting elements of the CDR 40 and bearing isolator 10 .
- This improved motor ground sealing system directly seats major elements together, which compensates for imperfections in the shaft 14 (which may not be perfectly round) and ensures the variation or change in distance from the conductive segments 46 to the surface of the shaft 14 caused by external forces acting on the CDR 40 and/or bearing isolator 10 are minimal. This promotes effective conduction of electrical charges from the shaft 14 to the equipment housing 16 .
- bearing isolator 10 and CDR 40 , 80 , 100 , 140 are not limited to the specific embodiments pictured and described herein, but are intended to apply to all similar apparatuses and methods for dissipating an electrical charge from a shaft 14 to an equipment housing 16 . Modifications and alterations from the described embodiments will occur to those skilled in the art without departure from the spirit and scope of the bearing isolator 10 and CDR 40 , 80 , 100 , 140 .
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Abstract
The current diverter rings and bearing isolators serve to dissipate an electrical charge from a rotating piece of equipment to ground, such as from a motor shaft to a motor housing. One embodiment of the current diverter ring includes an inner body and an outer body configured to clamp at least one conductive segment between them. In the preferred embodiments of the current diverter ring, the conductive segments are positioned in radial channels. The outer body may be affixed to a shaft, a motor housing, a bearing isolator, or other structure. The bearing isolator may incorporate a retention chamber for holding conductive segments within the stator of the bearing isolator, or the bearing isolator may be fashioned with a receptor groove into which a current diverter ring may be mounted.
Description
- The present application is a continuation of and claims priority from U.S. patent application Ser. No. 14/068,806 filed on Oct. 31, 2013, which application was a continuation of and claimed priority from U.S. patent application Ser. No. 13/089,017 filed on Apr. 18, 2011 (Now U.S. Pat. No. 8,604,653), all of which are incorporated by reference herein in their entireties.
- The present invention relates to an electrical charge dissipating device, and more particularly to a current diverter Ring™ for directing electrostatic charge to ground, which electrostatic charge is created through the use of rotating equipment.
- No federal funds were used to develop or create the invention disclosed and described in the patent application.
- Not Applicable
- A portion of the disclosure of this patent document may contain material that is subject to copyright and trademark protection. The copyright owner has no objection to the facsimile reproduction by anyone of the patent document or the patent disclosure, as it appears in the Patent and Trademark Office patent file or records, but otherwise reserves all copyrights whatsoever. CDR and Current Diverter Ring are the exclusive trademarks of Assignee, Inpro/Seal LLC.
- Adequate maintenance of rotating equipment, particularly electric motors, is difficult to obtain because of extreme equipment duty cycles, the lessening of service factors, design, and the lack of spare rotating equipment in most processing plants. This is especially true of electric motors, machine tool spindles, wet end paper machine rolls, aluminum rolling mills, steam quench pumps, and other equipment utilizing extreme contamination affecting lubrication.
- Various forms of shaft sealing devices have been utilized to try to protect the integrity of the bearing environment. These devices include rubber lip seals, clearance labyrinth seals, and attraction magnetic seals. Lip seals or other contacting shaft seals often quickly wear to a state of failure and are also known to permit excessive amounts of moisture and other contaminants to immigrate into the oil reservoir of the operating equipment even before failure has exposed the interface between the rotor and the stator to the contaminants or lubricants at the radial extremity of the seal. The problems of bearing failure and damage as applied to electrical motors using variable frequency drives (VFDs) is compounded because of the very nature of the control of electricity connected to VFD controlled motors.
- VFDs regulate the speed of a motor by converting sinusoidal line alternating current (AC) voltage to direct current (DC) voltage, then back to a pulse width modulated (PWM) AC voltage of variable frequency. The switching frequency of these pulses ranges from 1 kHz up to 20 kHz and is referred to as the “carrier frequency.” The ratio of change in voltage to the change in time (AV/AT) creates what has been described as a parasitic capacitance between the motor stator and the rotor, which induces a voltage on the rotor shaft. If the voltage induced on the shaft, which is referred to as “common mode voltage” or “shaft voltage,” builds up to a sufficient level, it can discharge to ground through the bearings. Current that finds its way to ground through the motor bearings in this manner is called “bearing current.”1 1 http://www.greenheck.com/technical/tech_detail.php?display=files/Product_guide/fal17_03
- There are many causes of bearing current including voltage pulse overshoot in the VFD, non-symmetry of the motor's magnetic circuit, supply imbalances, and transient conditions, among other causes. Any of these conditions may occur independently or simultaneously to create bearing currents from the motor shaft.2 2 http://www.greenheck.com/technical/tech_detail.php?display=files/Product_guide/fal17_03
- Shaft voltage accumulates on the rotor until it exceeds the dielectric capacity of the motor bearing lubricant, at which point the voltage discharges in a short pulse to ground through the bearing. After discharge, voltage again accumulates on the shaft and the cycle repeats itself. This random and frequent discharging has an electric discharge machining (EDM) effect, which causes pitting of the bearing's rolling elements and raceways. Initially, these discharges create a “frosted” or “sandblasted” effect on surfaces. Over time, this deterioration causes a groove pattern in the bearing race called “fluting,” which is an indication that the bearing has sustained severe damage. Eventually, the deterioration will lead to complete bearing failure.3 3 See www.Greenheck.com
- The prior art teaches numerous methods of mitigating the damage shaft voltages cause, including using a shielded cable, grounding the shaft, insulated bearings, and installation of a Faraday shield. For example, U.S. Pat. No. 7,193,836 discloses devices for controlling shaft current, which devices are designed to induce ionization in the presence of an electrical field.
- Most external applications add to costs, complexity, and exposure to external environmental factors. Insulated bearings provide an internal solution by eliminating the path to ground through the bearing for current to flow. However, installing insulated bearings does not eliminate the shaft voltage, which will continue to find the lowest impedance path to ground. Thus, insulated bearings are not effective if the impedance path is through the driven load. Therefore, the prior art does not teach an internal, low-wearing method or apparatus to efficaciously ground shaft voltage and avoid electric discharge machining of bearings leading to premature bearing failure.
- An objective of the current diverter ring is to provide an improvement to seals or bearing isolators to prevent leakage of lubricant and entry of contaminants by encompassing the stator within the rotor to create an axially directed interface at the radial extremity of the rotor. It is also an objective of the current diverter ring to disclose and claim an apparatus for rotating equipment that conducts and transmits and directs accumulated bearing current to ground.
- It is another objective of the bearing isolator as disclosed and claimed herein to facilitate placement of a current diverter ring within the stator of the bearing isolator. Conductive segments may be positioned within the current diverter ring. These conductive segments may be constructed of metallic or non-metallic solids, machined or molded. Although any type of material compatible with operating conditions and metallurgy may be selected, bronze, gold, carbon, or aluminum are believed to be preferred materials because of increased conductivity, strength, corrosion and wear resistance.
- It has been found that a bearing isolator having a rotor and stator manufactured from bronze has improved electrical charge dissipation qualities. The preferred bronze metallurgy is that meeting specification 932 (also referred to as 932000 or “bearing bronze”). This bronze is preferred for bearings and bearing isolators because it has excellent load capacity and antifriction qualities. This bearing bronze alloy also has good machining characteristics and resists many chemicals. It is believed that the specified bronze offers increased shaft voltage collection properties comparable to the ubiquitous lightning rod due to the relatively low electrical resistivity (85.9 ohms-cmil/ft @ 68 F or 14.29 microhm-cm @ 20 C) and high electrical conductivity (12% IACS @ 68 F or 0.07 MegaSiemens/cm @ 20 C) of the material selected.
- It is another object of the current diverter ring and bearing isolator to improve the electrical charge dissipation characteristics from those displayed by shaft brushes typically mounted external of the motor housing. Previous tests of a combination bearing isolator with a concentric current diverter ring fixedly mounted within the bearing isolator have shown substantial reduction in shaft voltage and attendant electrostatic discharge machining. Direct seating between the current diverter ring and the bearing isolator improves the conduction to ground over a simple housing in combination with a conduction member as taught by the prior art. Those practiced in the arts will understand that this improvement requires the electric motor base to be grounded, as is the norm.
- It is therefore an objective of the current diverter ring and bearing isolator to disclose and claim an electric motor for rotating equipment having a bearing isolator that retains lubricants, prevents contamination, and conducts and transmits bearing current to ground.
- It is another objective of the current diverter ring and bearing isolator to provide a bearing isolator for rotating equipment that retains lubricants, prevents contamination and conducts electrostatic discharge (shaft voltage) to improve bearing operating life.
- It is another objective of the current diverter ring to provide an effective apparatus to direct electrical charges from a shaft to a motor housing and prevent the electrical charge from passing to ground through the bearing(s).
- Other objects, advantages and embodiments of the current diverter ring and bearing isolator will become apparent upon the reading the following detailed description and upon reference to drawings.
- In order that the advantages of the invention will be readily understood, a more particular description of the invention briefly described above will be rendered by reference to specific embodiments illustrated in the appended drawings. Understanding that these drawings depict only typical embodiments of the invention and are not therefore to be considered limited of its scope, the invention will be described and explained with additional specificity and detail through the use of the accompanying drawings.
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FIG. 1 is a perspective view of one embodiment of an electric motor with which the current diverter ring may be employed. -
FIG. 2 is a perspective cross-sectional view of a bearing isolator wherein a portion of the stator is fashioned as a current diverter ring. -
FIG. 3 is a cross-sectional view of a bearing isolator configured to accept a current diverter ring within the stator portion of the bearing isolator. -
FIG. 4 is a perspective view of the first embodiment of the current diverter ring. -
FIG. 5 is an axial view of the first embodiment of the current diverter ring. -
FIG. 6 is a cross-sectional view of the first embodiment of the current diverter ring. -
FIG. 7 is a perspective, exploded view of a second embodiment of the current diverter ring. -
FIG. 8A is a perspective view of a second embodiment of the current diverter ring assembled. -
FIG. 8B is a perspective view of a second embodiment of the current diverter ring assembled with mounting clips. -
FIG. 9 is a detailed perspective view of one embodiment of an inner body for use with the second embodiment of the current diverter ring. -
FIG. 10A is an axial view of one embodiment of an inner body for use with the second embodiment of the current diverter ring. -
FIG. 10B is a cross-sectional view of one embodiment of an inner body for use with the second embodiment of the current diverter ring. -
FIG. 11 is a cross-sectional view of one embodiment of an inner body for use with the second embodiment of the current diverter ring with conductive fibers positioned therein. -
FIG. 12 is a detailed perspective view of one embodiment of an outer body for use with the second embodiment of the current diverter ring. -
FIG. 13A is an axial view of one embodiment of an outer body for use with the second embodiment of the current diverter ring. -
FIG. 13B is a cross-sectional view of one embodiment of an outer body for use with the second embodiment of the current diverter ring. -
FIG. 14A is an axial view of the second embodiment of the current diverter ring assembled. -
FIG. 14B is a cross-sectional view of the second embodiment of the current diverter ring assembled. -
FIG. 15A is a perspective view of a third embodiment of the current diverter ring. -
FIG. 15B is an axial cross section view of the third embodiment of the current diverter ring. -
FIG. 15C is a perspective view of one embodiment of a conductive assembly that may be used with certain embodiments of the CDR. -
FIG. 16A is a perspective view of a fourth embodiment of the current diverter ring. -
FIG. 16B is a perspective, exploded view of the fourth embodiment of the current diverter ring. -
FIG. 16C is an axial cross section view of the fourth embodiment of the current diverter ring. -
FIG. 16D is a detailed cross section view of the fourth embodiment of the current diverter ring. -
FIG. 17A is a perspective view of a fifth embodiment of the current diverter ring having a split design. -
FIG. 17B is a perspective, exploded view of the fifth embodiment of the current diverter ring. -
FIG. 17C is an axial cross section view of the fifth embodiment of the current diverter ring. -
FIG. 17D is a detailed cross section view of the fifth embodiment of the current diverter ring. -
FIG. 18A is a perspective view of one embodiment of an adaptable current diverter ring. -
FIG. 18B is an axial cross section view of one embodiment of an adaptable current diverter ring. -
DETAILED DESCRIPTION - ELEMENT LISTING Description Element No. Bearing isolator 10 Bearing 12 Shaft 14 Equipment housing 16 Sealing member 17 O-ring 18 Stator 20 Stator main body 22 Stator radial exterior surface 23 Receptor groove 24 Stator axial projection 26 Stator radial projection 28 Stator axial groove 29 Rotor 30 Rotor main body 32 Rotor axial exterior surface 33 First axial interface gap 34a First radial interface gap 34b Rotor axial projection 36 Rotor radial projection 38 Rotor axial groove 39 Current diverter ring ™ (CDR ®) 40 CDR body 41 Annular channel 42 First wall 43 Second wall 44 CDR radial exterior surface 45 Conductive segment 46 CDR main aperture 48 Inner body 50 Radial channel 52 Catch 52a Mounting aperture 54 Ridge (locking) 56 Inner body main aperture 58 Outer body 60 Base 62 Annular groove 64 First annular shoulder 65a Second annular shoulder 65b Radial projection 66 Outer body main aperture 68 Strap 70 Fastener 72 Radial CDR 80 Radial channel 82 Radial channel shelf 83 Radial exterior surface 85a Radial interior surface 85b Conductive assembly 86 Binder 86a Contact portion 86b Main aperture 88 Multi-ring CDR 100 Retainer 110 Retainer base 111 First annular groove 112a Second annular groove 112b Third annular groove 112c Fourth annular groove 112d Snap groove 113 Retainer wall 114 Retainer radial exterior surface 115 Conductive segment 116 Retainer main aperture 118 Ring 120 Radial channel 122 Catch 122a Ring radial exterior surface 125 Ridge 126 Interior axial surface 127a Exterior axial surface 127b Ring main aperture 128 Split ring segment 130 Backing ring 140 Alignment pin 141 Alignment pin receptor 142 Fastener bore 143 Fastener receptor 144 O-ring channel 145 Aperture 146 Backing ring fastener 148 Adaptable CDR 160 Slot 161 Radial channel 162 Radial channel shelf 163 Recess 164 Radial exterior surface 165a Radial interior surface 165b Cut out 166 Main aperture 168 - Before the various embodiments of the present 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 components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments and of being practiced or of being carried out in various ways. Also, it is to be understood that phraseology and terminology used herein with reference to device or element orientation (such as, for example, terms like “front”, “back”, “up”, “down”, “top”, “bottom”, and the like) are only used to simplify description of the present invention, and do not alone indicate or imply that the device or element referred to must have a particular orientation. In addition, terms such as “first”, “second”, and “third” are used herein and in the appended claims for purposes of description and are not intended to indicate or imply relative importance or significance. Additionally, the
terms CDR 40,radial CDR 80,multi-ring CDR 100, andadaptable CDR 160 may be used interchangeably when referring to generalities of configuration with a bearingisolator 10, methods and/or materials of construction, and/or other general features. - One embodiment of an
equipment housing 16 with which theCDR® 40 may be used is shown inFIG. 1 . TheCDR 40 may be press-fit into an aperture in theequipment housing 16, or it may be secured to the exterior of theequipment housing 16 usingstraps 70 andfasteners 72 as described in detail below and as shown inFIG. 1 . TheCDR 40 may also be secured to anequipment housing 12 via other structures and/or methods, such as chemical adhesion, welding, rivets, or any other structure and/or method suitable for the particular application. TheCDR 40 may also be configured to be engaged with a bearingisolator 10, or integrally formed with a bearingisolator 10, as described in detail below. -
FIG. 2 illustrates a perspective view of one embodiment of a bearingisolator 10 configured to discharge electrical impulses from theshaft 14 through theequipment housing 16. The bearingisolator 10 as shown inFIG. 2 may be mounted to arotatable shaft 10 on either one or both sides of theequipment housing 16. The bearingisolator 10 may be flange-mounted, press-fit (as shown inFIG. 2 ), or attached to theequipment housing 16 using any other method and/or structure suitable for the particular application, as was described above for theCDR 40. In some embodiments, set screws (not shown) or other structures and/or methods may be used to mount either thestator 20 to theequipment housing 16 or therotor 30 to theshaft 14. In another embodiment not pictured herein, theshaft 14 is stationary and theequipment housing 16 or other structure to which the bearingisolator 10 is mounted may rotate. - In another embodiment, the
CDR 40 and/or bearingisolator 10 may be mounted such that either theCDR 40 and/or bearingisolator 10 are allowed to float in one or more directions. For example, in one embodiment a portion of the bearingisolator 10 is positioned in an enclosure. The enclosure is fashioned as two opposing plates with main apertures therein, through which main apertures the shaft passes 14. The interior of the enclosure is fashioned such that the bearingisolator 10 and/orCDR 40 is positioned within a truncated circle (i.e., pill-shaped) recess on the interior of the enclosure. The contact points between the bearingisolator 10 and/orCDR 40 and the enclosure may be formed with a low friction substance, such as Teflon®, affixed thereto. - A more detailed cross-sectional view of one embodiment of a bearing
isolator 10 with which theCDR 40 may be used is shown inFIG. 3 . The bearingisolator 10 shown inFIGS. 2 and 3 includes astator 20 and arotor 30, and is commonly referred to as a labyrinth seal. Generally, labyrinth seals are well known to those skilled in the art and include those disclosed in U.S. Pat. Nos. 7,396,017; 7,090,403; 6,419,233; 6,234,489; 6,182,972; and 5,951,020; and U.S. Pat. App. Pub. No. 2007/0138748, all of which are incorporated by reference herein in their entireties. - The
stator 20 may be generally comprised of a statormain body 22 and various axial and/or radial projections extending therefrom and/or various axial and/or radial grooves configured therein, which are described in more detail below. In the embodiment shown inFIGS. 2 and 3 , thestator 20 is fixedly mounted to anequipment housing 16 with an O-ring 18 forming a seal therebetween. - The
rotor 30 may be generally comprised of a rotormain body 32 and various axial and/or radial projections extending therefrom and/or various axial and/or radial grooves configured therein, which are described in more detail below. In the embodiment shown, one statoraxial projection 26 cooperates with a rotoraxial groove 39, and one rotoraxial projection 36 cooperates with a statoraxial groove 29 to form a labyrinth passage between the interior portion of the bearingisolator 10 and the external environment. Therotor 30 may be fixedly mounted to ashaft 14 and rotatable therewith. An O-ring 18 may be used to form a seal therebetween. A sealingmember 17 may be positioned between thestator 20 androtor 30 on an interior interface therebetween to aide in prevention of contaminants entering the interior of the bearingisolator 10 from the external environment while simultaneously aiding in retention of lubricants in the interior of the bearingisolator 10. - In the embodiment of the bearing
isolator 10 shown inFIGS. 2 and 3 , onestator radial projection 28 provides an exterior groove in thestator 20 for collection of contaminants. A firstaxial interface gap 34 a may be formed between the radially exterior surface of a statorradial projection 28 and the radially interior surface of a rotorradial projection 38. A firstradial interface gap 34 b may be formed between the axially exterior surface of a statoraxial projection 26 and the axially interior surface of a rotoraxial groove 39. A rotoraxial projection 36 formed with a rotorradial projection 38 may be configured to fit within a statoraxial groove 29 to provide another axial interface gap between thestator 20 and therotor 30. - In the embodiment of a bearing
isolator 10 pictured herein, one rotor radial projection 38 (adjacent the rotor axial exterior surface 33) extends radially beyond the major diameter of the statoraxial projection 26. This permits therotor 30 to encompass the statoraxial projection 26. As is fully described in U.S. Pat. No. 6,419,233, which is incorporated by reference herein in its entirety, this radial extension is a key design feature of the bearingisolator 10 shown herein. The axial orientation of the firstaxial interface gap 34 a controls entrance of contaminants into the bearingisolator 10. Reduction or elimination of contaminants improves the longevity and performance of the bearingisolator 10, bearing 12, and conductive segment(s) 46. The opening of the firstaxial interface gap 34 a faces rearward, toward theequipment housing 16 and away from the contaminant stream. The contaminant or cooling stream will normally be directed along the axis of theshaft 14 and toward theequipment housing 16. - To facilitate the discharge of electric energy on or adjacent the
shaft 14, the bearingisolator 10 may include at least oneconductive segment 46 positioned within thestator 20. Thestator 20 may be configured with a conductive segment retention chamber adjacent thebearing 12, in which conductive segment retention chamber theconductive segment 46 may be positioned and secured such that theconductive segment 46 is in contact with theshaft 14. As electrical charges accumulate on theshaft 14, theconductive segment 46 serves to dissipate those charges through the bearingisolator 10 and to theequipment housing 16. The specific size and configuration of the conductive segment retention chamber will depend on the application of the bearingisolator 10 and the type and size of eachconductive segment 46. Accordingly, the size and configuration of the conductive segment annular channel is in no way limiting. - Configuring the conductive segment retention chamber as an annular channel it is not preferred. This configuration results in difficulties relating to, among other things, performance and manufacturing. A preferred configuration of the conductive segment retention chamber is a
radial channel 52, such as those described for theCDR 40 embodiment shown inFIGS. 7-14 or as described for theradial CDR 80, shown inFIGS. 15A-15C . - In the embodiment pictured herein, the bearing
isolator 10 is formed with areceptor groove 24. Thereceptor groove 24 may be fashioned on the inboard side of the bearingisolator 10 adjacent theshaft 14, as best shown inFIG. 3 . Generally, thereceptor groove 24 facilitates the placement of aCDR 40 within the bearingisolator 10. However, other structures may be positioned within thereceptor groove 24 depending on the specific application of the bearingisolator 10. - As shown and described, the bearing
isolator 10 inFIGS. 2 and 3 includes a plurality of radial and axial interface passages between thestator 20 and therotor 30 resulting from the cooperation of the 26, 28 withstator projections rotor grooves 39 and the cooperation of 36, 38 withrotor projections stator grooves 29. An infinite number of configurations and/or orientations of the various projections and grooves exist, and therefore the configuration and/or orientation of the various projections and grooves in thestator 20 and/orrotor 30 are in no way limiting. The bearingisolator 10 as disclosed herein may be used with anyconfiguration stator 20 and/orrotor 30 wherein thestator 20 may be configured with a conductive segment retention chamber for retaining at least oneconductive segment 46 therein or areceptor groove 24 as described in detail below. - A first embodiment of a current diverter ring (CDR) 40 is shown in perspective in
FIG. 4 , andFIG. 5 provides an axial view thereof. TheCDR 40 may be used with any rotating equipment that has a tendency to accumulate an electrical charge on a portion thereof, such as electrical motors, gearboxes, bearings, or any other such equipment. The first embodiment of theCDR 40 is designed to be positioned between anequipment housing 16 and ashaft 14 protruding from theequipment housing 16 and rotatable with respect thereto. - Generally, the
CDR 40 is comprised of aCDR body 41, which may be fixedly mounted to theequipment housing 16. In the first embodiment, afirst wall 43 and asecond wall 44 extend from theCDR body 41 and define anannular channel 42. At least oneconductive segment 46 is fixedly retained in theannular channel 42 so that theconductive segment 46 is in contact with theshaft 14 so as to create a low impedance path from theshaft 14 to theequipment housing 16. - A cross-sectional view of the first embodiment of the
CDR 40 is shown inFIG. 6 . As shown inFIG. 6 , the axial thickness of thefirst wall 43 is less than that of thesecond wall 44. In the first embodiment, theconductive segment 46 is retained within theannular channel 42 by first positioning theconductive segment 46 within theannular channel 42 and then deforming thefirst wall 43 to reduce the clearance between the distal ends of the first and 43, 44. Deforming thesecond walls first wall 43 in this manner retains theconductive segment 46 within theannular channel 42. Depending on the material used for constructing theconductive segment 46, the deformation of thefirst wall 43 may compress a portion of theconductive segment 46 to further secure the position of theconductive segment 46 with respect to theshaft 14. - A detailed view of the CDR radial
exterior surface 45 is shown inFIG. 6 . The CDR radialexterior surface 45 may be configured with a slight angle in the axial dimension so that theCDR 40 may be press-fit into theequipment housing 16. In the first embodiment, the angle is one degree, but may be more or less in other embodiments not pictured herein. Also, in the first embodiment thefirst wall 43 is positioned adjacent thebearing 12 when theCDR 40 is installed in anequipment housing 16. However, in other embodiments not shown herein, thesecond wall 44 may be positioned adjacent thebearing 12 when theCDR 40 is installed in anequipment housing 16, in which case the angle of the CDR radialexterior surface 45 would be opposite of that shown inFIG. 6 . The optimal dimensions/orientation of theCDR body 41,annular channel 42,first wall 43,second wall 44, and CDR radialexterior surface 45 will vary depending on the specific application of theCDR 40 and are therefore in no way limiting to the scope of theCDR 40. - As was true for the bearing
isolator 10, aCDR 40 with a conductive segment retention chamber configured as an annular channel is not preferred. Performance and manufacturing considerations are among the reasons such a configuration is not preferred. Instead, the other embodiments of the CDR disclosed herein, which do not have anannular channel 42 and the attending difficulties, are preferred. - In other embodiments of the
CDR 40 described in detail below, theCDR 40 is mounted to theequipment housing 16 using mountingapertures 54, straps 70, andfasteners 72 fashioned in either theCDR 40 orequipment housing 16. TheCDR 40 may be mounted to theequipment housing 16 by any method using any structure suitable for the particular application without departing from the spirit and scope of theCDR 40. - In the embodiment of the
CDR 40 shown inFIGS. 4 and 5 , threeconductive segments 46 are positioned within theannular channel 42. The optimal number ofconductive segments 46 and the size and/or shape of eachconductive segment 46 will vary depending on the application of theCDR 40, and is therefore in no way limiting. The optimal total length of allconductive segments 46 and the total surface area of theconductive segments 46 that are in contact with theshaft 14 will vary from one application to the next, and is therefore in no way limiting to the scope of theCDR 40 or of a bearingisolator 10 configured with conductive segments 46 (such as the bearing isolator shown inFIGS. 2 and 3 ). - In the embodiment shown in
FIGS. 4-6 , theCDR 40 may be sized to be engaged with a bearingisolator 10 having areceptor groove 24, such as the bearingisolator 40 shown inFIGS. 2 and 3 . As described above,FIGS. 2 and 3 shown one embodiment of a bearingisolator 10 fashioned to engage aCDR 40. Thereceptor groove 24 may be formed as a recess in thestator 20 that is sized and shaped to accept aCDR 40 similar to the one shown inFIGS. 4-6 , or other embodiments of theCDR 40 disclosed herein. TheCDR 40 may be press-fit into thereceptor groove 24, or it may be affixed to thestator 20 by any other method or structure that is operable to fixedly mount theCDR 40 to thestator 20, including but not limited to set screws, welding, etc. When theCDR 40 is properly engaged with thereceptor groove 24 in thestator 20, the CDR radialexterior surface 45 abuts and contacts the interior surface of thereceptor groove 24. - In any of the embodiments of the
CDR 40 or bearingisolator 10 employingconductive segments 46, theconductive segment 46 may be constructed of carbon, which is conductive and naturally lubricious. In one embodiment, theconductive segment 46 is constructed of a carbon mesh manufactured by Chesterton and designated 477-1. In other embodiments theconductive segment 46 has no coating on the exterior of the carbon mesh. When mesh or woven materials are used to construct theconductive segments 46, often the surface of theconductive segment 46 that contacts theshaft 14 becomes frayed or uneven, which may be a desirable quality to reduce rotational friction in certain applications. Shortly after theshaft 14 has been rotating with respect to theconductive segments 46, certain embodiments of theconductive segments 46 will wear and abrade from the surface of theshaft 14 so that friction between theconductive segments 46 and theshaft 14 is minimized. Theconductive segments 46 may be fibrous, solid, or other material without limitation. - In general, it is desirable to ensure that the impedance from the
shaft 14 to theequipment housing 16 is in the range of 0.2 to 10 ohms to ensure that electrical charges that have accumulated on theshaft 14 are discharged through theequipment housing 16 and to the base of the motor (not shown) rather than through the bearing(s) 12. The impedance from theshaft 14 to theequipment housing 16 may be decreased by ensuring the fit between the bearingisolator 10 andequipment housing 16, bearingisolator 10 andCDR 40, and/orCDR 40 andequipment housing 16 has a very small tolerance. Accordingly, the smaller the gap between the bearingisolator 10 andequipment housing 16, bearingisolator 10 andCDR 40, and/orCDR 40 andequipment housing 16, the lower the impedance from theshaft 14 to theequipment housing 16. - In other embodiments not pictured herein, conductive filaments (not shown) may be affixed to either the
CDR 40 or bearingisolator 10 or embedded inconductive segments 46 affixed to either theCDR 40 or bearingisolator 10. Such filaments may be constructed of aluminum, copper, gold, carbon, conductive polymers, conductive elastomers, or any other conductive material possessing the proper conductivity for the specific application. Any material that is sufficiently lubricious and with sufficiently low impedance may be used for the conductive segment(s) 46 in theCDR 40 and/or bearingisolator 10. - In another embodiment of the
CDR 40 not pictured herein, theCDR 40 is affixed to theshaft 14 and rotates therewith. The first and 43, 44 of thesecond walls CDR 40 extend from theshaft 14, and the CDRmain body 41 is adjacent theshaft 14. The centrifugal force of the rotation of theshaft 14 causes theconductive segments 46 and/or conductive filaments to expand radially as theshaft 14 rotates. This expansion allows theconductive segments 46 and/or filaments to make contact with theequipment housing 16 even if grease or other contaminants and/or lubricants (which increase impedance and therefore decrease the ability of theCDR 40 to dissipate electrical charges from theshaft 14 to the equipment housing 16) have collected in an area between theCDR 40 and theequipment housing 16. - In another embodiment not pictured herein, a conductive sleeve (not shown) may be positioned on the
shaft 14. This embodiment is especially useful for ashaft 14 having a worn or uneven surface that would otherwise lead to excessive wear of theconductive segments 46. The conductive sleeve (not shown) may be constructed of any electrically conductive material that is suitable for the particular application, and the conductive sleeve (not shown) may also be fashioned with a smooth radial exterior surface. The conductive sleeve (not shown) would then serve to conductive electrical charges from theshaft 14 to theconductive segments 46 in either theCDR 40 or a bearingisolator 10. Another embodiment that may be especially useful for use withshafts 14 having worn or uneven exterior surfaces is an embodiment wherein conductive filaments or wires are inserted into theconductive segments 46. These conductive filaments or wires may be sacrificial and fill in depressions or other asperities of the surface of theshaft 14. - In another embodiment not pictured herein, conductive screws (not shown) made of suitable conductive materials may be inserted into the
conductive segments 46. Furthermore, spring-loaded solid conductive cylinders may be positioned within theCDR 40 and/or bearingisolator 10 in the radial direction so as to contact the radial exterior surface of theshaft 14. - Although elegant in its design, the
CDR 40 shown inFIGS. 4-6 is not the preferred embodiment of theCDR 40, as previously mentioned. Among other considerations, performance and manufacturing difficulties with this design dictate that other embodiments of theCDR 40 are more desirable. Particularly, the two-piece CDR 40 shown inFIGS. 7-14 and described in detail below and theradial CDR 80 shown inFIGS. 15A, 15B result in both of those embodiments being superior to that shown inFIGS. 4-6 . - A second embodiment of a
CDR 40 is shown inFIGS. 7-14 . In the second embodiment of theCDR 40, the CDR is formed from the engagement of aninner body 50 with anouter body 60, which are shown disengaged but in relation to one another inFIG. 7 . Theinner body 50 andouter body 60 in the second embodiment of theCDR 40 engage one another in a snapping, interference-type fit, which is described in detail below. - A perspective view of an
inner body 50, which may be generally ring shaped, is shown inFIG. 9 . Theinner body 50 may include at least oneradial channel 52 fashioned in an exterior face of theinner body 50, which includes amain aperture 58 through which ashaft 14 may be positioned. The embodiment pictured inFIG. 9 includes threeradial channels 52, but other embodiments may have a greater or lesser number ofradial channels 52, and therefore the number of radial channels in no way limits the scope of theCDR 40. Eachradial channel 52 may be formed with acatch 52 a therein to more adequately secure certain types ofconductive segments 46. It is contemplated that acatch 52 a will be most advantageous withconductive segments 46 made of a deformable or semi-deformable material (as depicted inFIG. 14B ), but acatch 52 a may be used withconductive segments 46 constructed of materials having different mechanical properties. Theradial channels 52 as shown are configured to open toward ashaft 14 positioned in themain aperture 58. Theinner body 50 may be formed with aridge 56 on the radial exterior surface thereof. Theridge 56 may be configured to engage theannular groove 64 formed in theouter body 60 as described in detail below. - The
inner body 50 may be formed with one or more mountingapertures 54 therein. The embodiment shown inFIGS. 8-11 is formed with three mountingapertures 54. Mountingapertures 54 may be used to secure theCDR 40 to anequipment housing 16 or other structure as shown inFIG. 1 . Astrap 70 or clip may be secured to theCDR 40 using afastener 72, such as a screw or rivet, engaged with a mountingaperture 54, as shown inFIGS. 1 and 8B . The presence or absence of mountingapertures 54 will largely depend on the mounting method of theCDR 40. For example, in the embodiment shown inFIGS. 14A and 14B , theinner body 50 does not include any mountingapertures 54. It is contemplated that such embodiments will be optimal for use within a bearingisolator 10 and/or aCDR 40 that will be press fit into anequipment housing 16 or other structure. - A perspective view of an
outer body 60, which also may be generally ring shaped, is shown inFIG. 12 . Theouter body 60 may be formed with a base 62 having anannular groove 64 formed on the radial interior surface thereof. Theannular groove 64 may be defined by a first annular shoulder 64 a and a secondannular shoulder 65 b. Aradial projection 66 may extend radially inward from the base 62 adjacent either the first and/or 65 a, 65 b. In the embodiment pictured, thesecond shoulder radial projection 66 is positioned adjacent the firstannular shoulder 65 a and includes amain aperture 68 therein, through which ashaft 14 may be positioned. - The
annular groove 64 may be configured such that theridge 56 formed in theinner body 50 engages theannular groove 64 so as to substantially fix the axial position of theinner body 50 with respect to theouter body 60. As shown inFIGS. 10B, and 14B , theridge 56 may be slanted or tapered so that upon forced insertion of theinner body 50 in theouter body 60, theridge 56 slides past the secondannular shoulder 65 b and into theannular groove 64 to axially secure theinner body 50 and theouter body 60. The engagement between theridge 56 and theannular groove 64 thereafter resists separation or dissociation of the inner and 50, 60. In other embodiments not shown herein, theouter bodies ridge 56 is not limited to a tapered configuration. Theridge 56 andbase 62 may also be configured so an interference fit is created upon engagement to resist separation or disassociation of the inner and 50, 60.outer bodies - As shown in
FIGS. 14A and 14B , theinner body 50 andouter body 60 may be configured so that the interior periphery of theradial projection 66 has the same diameter as the interior periphery of theinner body 50 so that both the inner and 50, 60 have the same clearance from aouter bodies shaft 14 when installed. It is contemplated that in most applications theCDR 40 will be installed so that the surface shown inFIG. 14A is axially exterior to theequipment housing 16 or other structure. However, if theCDR 40 is engaged with a bearingisolator 10, theCDR 40 may be oriented such that the surface shown inFIG. 14A is facing toward the interior of theequipment housing 16 or other structure to which the bearingisolator 10 is mounted. - As shown in
FIG. 11 ,conductive segments 46 may be positioned in eachradial channel 52. It is contemplated that theradial channels 52 will be fashioned in the axial surface of theinner body 50 that is positioned adjacent theradial projection 66 of theouter body 60 when theCDR 40 is assembled, as shown inFIGS. 14A and 14B . This orientation secures the axial position of theconductive segments 46. As mentioned previously, aCDR 40 employingradial channels 52 for retention ofconductive segments 52 is preferred as compared to aCDR 40 having anannular channel 42. Typically, but depending on the materials of construction, theconductive segments 46 are sized so as to extend past the minor diameter of theinner body 50 into themain aperture 58 to contact theshaft 14. Theradial channels 52 are sized so as to not intersect the outer periphery of theinner body 50. This prevents theconductive segment 46 from contacting theannular groove 64 of theouter body 60. - The bearing
isolator 10 andCDR 40 may be constructed from any machinable metal, such as stainless steel, bronze, aluminum, gold, copper, and combinations thereof, or other material having low impedance. TheCDR 40 or bearingisolator 10 may be flange-mounted, press-fit, or attached to theequipment housing 16 by any other structure or method, such as through a plurality ofstraps 70 andfasteners 72. - In certain applications, performance of the bearing
isolator 10 may be improved by eliminating the O-rings 18 and their companion grooves fashioned in thestator 20 and therotor 30, as shown inFIGS. 2 and 3 . The high-impedance nature of material used to construct the O-ring 18 (such as rubber and/or silicon) may impede conductivity between bearingisolator 10 and theequipment housing 16, thereby decreasing the overall electrical charge dissipation performance of the bearingisolator 10. However, if the O-rings 18 may be constructed of a low-impedance material, they may be included in any application of theCDR 40 and/or bearingisolator 10. The optimal dimensions/orientation of theCDR 40,inner body 50,outer body 60, and various features thereof will vary depending on the specific application of theCDR 40 and are therefore in no way limiting to the scope of theCDR 40. - A
radial CDR 80 is another embodiment of aCDR 40, which is shown inFIGS. 15A, 15B as a ring-shaped structure having amain aperture 88 in the center thereof. As with other embodiments of theCDR 40 disclosed herein, theCDR 40 may be mounted to rotational equipment through any structure and/or method without limitation. The embodiment of theradial CDR 80 shown inFIGS. 15A and 15B includes threestraps 70 affixed to theradial CDR 80 viafasteners 72.Other fasteners 72 may be used to secure thestraps 70 to the rotational equipment, thereby securing theradial CDR 80 to the rotational equipment. In other embodiments of theradial CDR 80, theradial exterior surface 85 a of theradial CDR 80 is press-fit into therotational equipment housing 16. However, the mounting method for the radial CDR is in no way limiting to its scope. - The embodiment of the
radial CDR 80 shown herein includes threeradial channels 82 extending from theradial exterior surface 85 a to the radialinterior surface 85 b. Eachradial channel 82 may include aradial channel shelf 83, which is best shown inFIG. 15B . In the pictured embodiment, theradial channel shelf 83 is located adjacent the radialinterior surface 85 b of theradial CDR 80. - A
conductive assembly 86 may be configured to securely fit within theradial channel 82. One embodiment of aconductive assembly 86 is shown in detailed inFIG. 15C . Theconductive assembly 86 may comprise abinder 86 a that is primarily located within theradial channel 82 and acontact portion 86 b that extends radially inward from theradial channel 82. Thebinder 86 a may be formed as any structure that retains the elements of theconductive assembly 86, including but not limited to a chemical adhesive, structural cap or tether, or combinations thereof. Other types ofconductive assemblies 86 may be used with theradial CDR 80 without limitation. - The
conductive assemblies 86 in theradial CDR 80 may be configured to be replaceable. That is, once thecontact portion 86 b of aconductive assembly 86 has been exhausted, or theconductive assembly 86 should otherwise be replaced, the user may remove theconductive assembly 86 from theradial channel 82 and insert a newconductive assembly 86 therein. - A first embodiment of a
multi-ring CDR 100 is shown inFIGS. 16A-16D . This embodiment of amulti-ring CDR 100 is similar to the two-piece CDR 40 described in detail above and shown inFIGS. 7-14B . Themulti-ring CDR 100 includes aretainer 110 with which at least tworings 120 are secured. Theretainer 110 may be substantially ring-shaped with a retainermain aperture 118 in the center thereof, which retainermain aperture 118 corresponds to each ringmain aperture 128. - The
retainer 110 may be formed with a plurality of 112 a, 112 b, 112 c, 112 d on the radial interior surface of theannular grooves retainer base 111 to provide seating surfaces for the various rings 120. The embodiment of themulti-ring CDR 100 shown herein includes a total of fourrings 120 and four annular grooves 112. However, other embodiments may be a greater or smaller number ofrings 120 and corresponding annular grooves 112 without limiting the scope of themulti-ring CDR 100. - The
rings 120 may be formed with a plurality ofradial channels 122 similar to those formed in theinner body 50 for the embodiment of theCDR 40 shown inFIGS. 7-14 . Theradial channel 116 is typically formed on the interioraxial surface 127 a of thering 120. Aconductive segment 116 may be positioned in eachradial channel 122. Additionally, eachradial channel 122 may be formed with acatch 122 a therein to better retain theconductive segment 116. - A
retainer wall 114 may extend radially inward from the firstannular groove 112 a toward the retainermain aperture 118, whichretainer wall 114 is analogous to theradial projection 66 of theouter body 60 for theCDR 40 embodiment shown inFIGS. 7-14 . In the embodiments pictured herein, theretainer wall 114 is substantially perpendicular to theretainer base 111. Theretainer wall 114 may serve as a stop for theinnermost ring 120 as shown inFIGS. 16C and 16D . The interioraxial surface 127 a of theinnermost ring 120 may abut theretainer wall 114, thereby compressing theconductive segments 116 positioned in theradial channels 122 of theinnermost ring 120 between thering 120 and theretainer wall 114. The ring radialexterior surface 125 of theinnermost ring 120 may engage the firstannular groove 112 a in such a manner as to secure theinnermost ring 120 to theretainer 110 via an interference fit. - The interior
axial surface 127 a of thering 120 immediately exterior to theinnermost ring 120 may abut the exterioraxial surface 127 b of theinnermost ring 120, thereby compressing theconductive segments 116 positioned in the radial channels 112 of thatring 120 between thatring 120 and theinnermost ring 120. The ring radialexterior surface 125 of thering 120 immediately exterior to theinnermost ring 120 may engage the secondannular groove 112 b in such a manner as to secure thatring 120 to the retainer via an interference fit. This is shown in detail inFIGS. 16C and 16D . The arrangement may continue with allrings 120 engaged with theretainer 110. - The
outermost ring 120 may be configured with aridge 162 on the ring radialexterior surface 125. Thisridge 162 may be angled upward from the interioraxial surface 127 a to the exterioraxial surface 127 b, such that theridge 126 engages asnap groove 113 that may be formed in the outermost annular groove 112 (which is the fourthannular groove 112 d in the embodiment shown herein). Accordingly, theoutermost ring 120 may be secured to theretainer 110, thereby securing allother rings 120, through the engagement of theridge 126 with thesnap groove 113. This is analogous to the engagement of theinner body 50 with theouter body 60 via theridge 56 andannular groove 64, respectively located on theinner body 50 andouter body 60 for theCDR 40 shown inFIGS. 7-14 . - In a split embodiment of a
multi-ring CDR 100, therings 120 may be secured to theretainer 110 using fasteners, such as fasteners, as shown inFIGS. 17A-17D . Therings 120 in this embodiment may be comprised of tworing segments 130, and theretainer 110 may be formed as two separate pieces. The interaction between the innermostsplit ring segments 130 and theretainer 110 is analogous to that described above for the first embodiment of themulti-ring CDR 100. Furthermore, the interaction between adjacentsplit ring segments 130 and the corresponding retention ofconductive segments 116 for the splitmulti-ring CDR 100 is analogous to that described for the first embodiment of themulti-ring CDR 100. To retain thesplit ring segments 130, an interference fit between the ring radialexterior surface 125 and individual 112 a, 112 b, 112 c, 112 d in conjunction with aannular grooves snap groove 113 in the outermost annular groove 112 and aridge 126 in theoutermost ring 120. The interference fit securement mechanism may be employed alone or in combination with a plurality offasteners 72, or the plurality offasteners 72 may be solely employed as a securement mechanism. Iffasteners 72 are used, thering segments 130 may be formed withapertures 132 to receive thefasteners 72. - A
backing ring 140 may be used with certain embodiments of the 40, 80, 100, as shown inCDR FIGS. 17A-17D . Thebacking ring 140 may also be formed of two distinct pieces, which pieces may be secured to one another through a plurality of correspondingalignment pin receptors 142, fastener bores 143,fastener receptors 144 and corresponding alignment pins 141 andfasteners 72. In the embodiment shown inFIG. 17B , twoalignment pins 141 and correspondingalignment pin receptors 142 are positioned at the seam of thebacking ring 140 to properly align the two pieces. Twofasteners 72 may be placed in respective fastener bores 143 so that a portion of eachfastener 72 engages arespective fastener receptor 144, thereby securing the two pieces of thebacking ring 140 to one another. - The
backing ring 140 may be manufactured so that the gap between the two pieces is negligible so as to prevent ingress of contaminants to and egress of lubricants from the bearing location. To do this, first a circle may be bisected across its diameter. The two pieces, when joined, form an ellipse due to the material removed during cutting. Accordingly, the two pieces may be machined so that together they form a perfect or near perfect circle.Alignment pin receptors 142 and corresponding alignment pins 141 and/or fastener bores 143 andcorresponding fasteners 72 may be used alone or in combination to secure the relative positions of the two pieces (as described above) during the machining. Relative stability of the two pieces is required to create a perfect or near perfect circle from the two pieces. At this point the backing ringmain aperture 148 and O-ring channel 145 may be fashioned in thebacking ring 140 to the desired specifications.Apertures 146 may be fashioned in thebacking ring 140 per the user's requirements so that the perfectly or near perfectlycircular backing ring 140 may be properly centered over a shaft or other structure. - One embodiment of an
adaptable CDR 160 is shown inFIGS. 18A and 18B . Theadaptable CDR 160 is designed so that it may be mounted to a wide variety of rotational equipment with different geometries. The adaptable CDR may include a plurality ofradial channels 162 that extend from the radial exterior surface 165 a to the radial interior surface 165 b adjacent themain aperture 168. Like theradial channels 82 in theradial CDR 80, theradial channels 162 in theadaptable CDR 160 may include aradial channel shelf 163. Accordingly, aconductive assembly 86 may secured in eachradial channel 162. - It is contemplated that the user will drill and tap holes in the exterior of the rotational equipment such that a
fastener 72 may pass through each of theslots 161 formed in theadaptable CDR 160. Theadaptable CDR 160 may include a plurality ofrecesses 164 to better accommodate differences in the exterior of various rotational equipment. Theadaptable CDR 160 may have a cut out 166 protruding into themain aperture 168 to facilitate installation of theadaptable CDR 160 over a shaft or other object. - The bearing
isolator 10 and/orCDR 40 employed with anequipment housing 16 creates a stable, concentric system with the rotatingshaft 14 as the center point. Inserting aCDR 40 into bearingisolator 10 such as the one shown inFIGS. 2 and 3 within theequipment housing 16 forms a relatively fixed and stable spatial relationship between the conducting elements, thereby improving the collection and conduction of electrostatic discharge from theshaft 14 to ground, through the conducting elements of theCDR 40 and bearingisolator 10. This improved motor ground sealing system directly seats major elements together, which compensates for imperfections in the shaft 14 (which may not be perfectly round) and ensures the variation or change in distance from theconductive segments 46 to the surface of theshaft 14 caused by external forces acting on theCDR 40 and/or bearingisolator 10 are minimal. This promotes effective conduction of electrical charges from theshaft 14 to theequipment housing 16. - Having described the preferred embodiments, other features of the
40, 80, 100, 160 and disclosed bearingCDR isolators 10 will undoubtedly occur to those versed in the art, as will numerous modifications and alterations in the embodiments as illustrated herein, all of which may be achieved without departing from the spirit and scope of the 40, 80, 100, 160 and/or bearingCDR isolator 10. It should be noted that the bearingisolator 10 and 40, 80, 100, 140 are not limited to the specific embodiments pictured and described herein, but are intended to apply to all similar apparatuses and methods for dissipating an electrical charge from aCDR shaft 14 to anequipment housing 16. Modifications and alterations from the described embodiments will occur to those skilled in the art without departure from the spirit and scope of the bearingisolator 10 and 40, 80, 100, 140.CDR
Claims (19)
1. A multi-ring current diverter ring comprising:
a. a retainer comprising:
i. a retainer base extending in the axial direction, wherein an outer surface of said retainer base is defined as a retainer radial exterior surface;
ii. a first annular groove formed on an inner surface of said retainer base;
iii. a retainer wall extending radially inward from said retainer base; and
iv. a second annular groove formed on said inner surface of said retainer base;
b. a first ring comprising:
i. a radial channel fashioned in an interior axial surface of said first ring, wherein said interior axial surface of said first ring abuts said retainer wall;
ii. a radial ring exterior surface abutting said first annular groove; and
iii. an exterior axial surface opposite said retainer wall;
c. a second ring comprising:
i. a radial channel fashioned in an interior axial surface of said second ring, wherein said interior axial surface of said second ring abuts said exterior axial surface of said first ring;
ii. a radial ring exterior surface abutting said second annular groove; and
iii. an exterior axial surface opposite said first ring.
d. a conductive segment, wherein said conductive segment is positioned in said radial channel of said first ring.
2. The multi-ring current diverter ring according to claim 1 wherein said first ring is further defined as being comprised of two split ring segments.
3. The multi-ring current diverter ring according to claim 2 wherein said two spilt ring segments further comprise an aperture formed therein, wherein said aperture extends from said interior axial surface to said exterior axial surface.
4. The multi-ring current diverter ring according to claim 3 further comprising at least one fastener simultaneously engaging a portion of said first ring and a portion of said second ring.
5. The multi-ring current diverter ring according to claim 1 wherein said first ring further comprises a plurality of radial channels and said second ring further comprises a plurality of radial channels.
6. The multi-ring current diverter ring according to claim 5 further comprising a plurality of conductive segments, wherein each said conductive segment is positioned in one of said radial channels in said first and second rings.
7. The multi-ring current diverter ring according to claim 1 further comprising a backing ring, wherein said retainer is engagable with said backing ring.
8. The multi-ring current diverter ring according to claim 7 wherein said backing ring is further defined as comprising two distinct portions.
9. A multi-ring current diverter ring comprising:
a. a first ring comprising:
i. a body that is substantially ring-shaped;
ii. a main aperture positioned in the center of said main body;
iii. a plurality of radial channels, wherein each said radial channel extends from the radial exterior surface of said body to the radial interior surface of said body;
iv. a radial channel shelf, wherein said radial channel shelf is positioned in one of said radial channels adjacent the radial interior surface of said main body; and,
v. a conductive assembly positioned in one of said radial channels, wherein a contact portion of said conductive assembly protrudes from said radial channel radially inward past said radial interior surface.
b. a second ring positioned adjacent said first ring, said second ring comprising:
i. a body that is substantially ring-shaped;
ii. a main aperture positioned in the center of said main body;
iii. a plurality of radial channels, wherein each said radial channel extends from the radial exterior surface of said body to the radial interior surface of said body;
iv. a radial channel shelf, wherein said radial channel shelf is positioned in one of said radial channels adjacent the radial interior surface of said main body; and,
v. a conductive assembly positioned in one of said radial channels, wherein a contact portion of said conductive assembly protrudes from said radial channel radially inward past said radial interior surface.
10. The multi-ring current diverter ring according to claim 9 wherein said first and second ring are further defined as being engaged with one another.
11. The multi-ring current diverter ring according to claim 10 wherein said first and second ring are further defined as being engaged with one another via a fastener.
12. The multi-ring current diverter ring according to claim 9 further comprising a backing ring configured to engage a housing.
13. The multi-ring current diverter ring according to claim 9 wherein said conductive assembly comprises a carbon-based filament.
14. The multi-ring current diverter ring according to claim 9 wherein said plurality of radial channels in said first and second rings is further defined as three radial channels.
15. The multi-ring current diverter ring according to claim 14 further comprising a plurality of conductive assemblies corresponding to said plurality of radial channels in said first and second rings.
16. The multi-ring current diverter ring according to claim 9 wherein said plurality of radial channels is further defined as being equally spaced about said body.
17. The multi-ring current diverter ring according to claim 9 wherein said bodies of said first and second rings further comprise a plurality of mounting apertures positioned in an axial face thereof, and wherein a plurality of fasteners and straps cooperatively engage said plurality of mounting apertures.
18. The multi-ring current diverter ring according to claim 9 wherein said conductive assembly comprises a binder and a contact portion, and wherein said contact portion extends into said main aperture.
19. A method of dissipating an electrical charge from a shaft through a motor housing comprising:
a. fixing a current diverter ring to said motor housing;
b. mounting at least one conductive segment within said current diverter ring, wherein said at least one conductive segment is in close proximity to or in contact with said shaft;
c. transmitting said electrical charge from said shaft to said at least one conductive segment;
d. transmitting said electrical charge from said at least one conductive segment to said current diverter ring; and
e. transmitting said electrical charge from said current diverter ring to said motor housing.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US15/351,213 US20170077663A1 (en) | 2011-04-18 | 2016-11-14 | Current Diverter Ring |
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US13/089,017 US8604653B2 (en) | 2005-06-25 | 2011-04-18 | Current diverter ring |
| US14/068,806 US9525327B2 (en) | 2011-04-18 | 2013-10-31 | Current diverter ring |
| US15/351,213 US20170077663A1 (en) | 2011-04-18 | 2016-11-14 | Current Diverter Ring |
Related Parent Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| US14/068,806 Continuation US9525327B2 (en) | 2011-04-18 | 2013-10-31 | Current diverter ring |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| US20170077663A1 true US20170077663A1 (en) | 2017-03-16 |
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ID=47042147
Family Applications (3)
| Application Number | Title | Priority Date | Filing Date |
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| US13/089,017 Active 2026-07-22 US8604653B2 (en) | 2005-06-25 | 2011-04-18 | Current diverter ring |
| US14/068,806 Expired - Fee Related US9525327B2 (en) | 2011-04-18 | 2013-10-31 | Current diverter ring |
| US15/351,213 Abandoned US20170077663A1 (en) | 2011-04-18 | 2016-11-14 | Current Diverter Ring |
Family Applications Before (2)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| US13/089,017 Active 2026-07-22 US8604653B2 (en) | 2005-06-25 | 2011-04-18 | Current diverter ring |
| US14/068,806 Expired - Fee Related US9525327B2 (en) | 2011-04-18 | 2013-10-31 | Current diverter ring |
Country Status (9)
| Country | Link |
|---|---|
| US (3) | US8604653B2 (en) |
| EP (1) | EP2710693A4 (en) |
| JP (1) | JP6163480B2 (en) |
| KR (1) | KR101970367B1 (en) |
| CN (1) | CN103548219B (en) |
| BR (1) | BR112013027003A2 (en) |
| CA (1) | CA2833565A1 (en) |
| MX (1) | MX2013012217A (en) |
| WO (1) | WO2012145445A2 (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2020194191A1 (en) * | 2019-03-25 | 2020-10-01 | Troy Lance Timm | Grounding device |
| CN114382867A (en) * | 2020-10-06 | 2022-04-22 | 采埃孚股份公司 | Shaft grounding assemblies, transmissions and trolley drives |
Families Citing this family (40)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US8604653B2 (en) * | 2005-06-25 | 2013-12-10 | Inpro/Seal, LLC | Current diverter ring |
| KR20180091105A (en) * | 2011-05-26 | 2018-08-14 | 유나이티드 파이프라인스 아시아 패시픽 피티이 리미티드 | Austenitic stainless steel |
| WO2013086531A1 (en) | 2011-12-08 | 2013-06-13 | Inpro/Seal Llc | Current diverter ring |
| 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 |
| US20150226220A1 (en) * | 2014-02-13 | 2015-08-13 | Pentair Flow Technologies, Llc | Pump and Electric Insulating Oil for Use Therein |
| US9917491B2 (en) * | 2014-03-07 | 2018-03-13 | Nidec Motor Corporation | Ground ring and enclosure in an electric motor |
| CN105337439B (en) * | 2014-06-09 | 2019-03-15 | 德昌电机(深圳)有限公司 | Driving device and its motor |
| KR101512945B1 (en) * | 2014-08-29 | 2015-04-16 | 현대중공업 주식회사 | Explosion proof motor having function for preventing oil leakage |
| BR112017012887B1 (en) * | 2014-12-19 | 2022-01-04 | Weg Equipamentos Elétricos S.a. | BEARING GROUNDING SYSTEM FOR ROTATING ELECTRICAL MACHINES AND CORRESPONDING ELECTRICAL MACHINE |
| DE102015206520A1 (en) * | 2015-04-13 | 2016-10-13 | Schunk Bahn- Und Industrietechnik Gmbh | deriving means |
| EP3286462B1 (en) | 2015-04-21 | 2024-06-12 | Inpro/Seal LLC | Shaft seal assembly |
| US10927961B2 (en) | 2015-04-21 | 2021-02-23 | Inpro/Seal Llc | Shaft seal assembly |
| CN104832653B (en) * | 2015-05-05 | 2017-01-11 | 湖北新置密封件有限公司 | Sealing device for high-speed rotating shaft |
| CN104948742B (en) * | 2015-05-11 | 2017-03-22 | 湖北新置密封件有限公司 | Non-contact type one-way sealing device used for high-speed rotary shafts |
| BR112017027248A2 (en) | 2015-06-18 | 2018-08-28 | Inpro/Seal Llc | rod seal assembly |
| GB201519362D0 (en) * | 2015-11-02 | 2015-12-16 | Aes Eng Ltd | Electrical grounding of bearing seal |
| DE102016207672A1 (en) * | 2016-05-04 | 2017-11-09 | Bayerische Motoren Werke Aktiengesellschaft | Sealing system for a shaft |
| WO2017213627A1 (en) * | 2016-06-07 | 2017-12-14 | Schlumberger Technology Corporation | System and method for reducing motor bearing currents |
| 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 |
| 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 |
| DE102018107408B4 (en) * | 2018-03-28 | 2022-10-27 | Schunk Carbon Technology Gmbh | Diverting device for diverting electrical currents |
| DE102018208823B4 (en) * | 2018-06-05 | 2025-02-27 | Bayerische Motoren Werke Aktiengesellschaft | Contacting element for electrically contacting a shaft of an electric drive unit of a motor vehicle, electric drive unit and motor vehicle |
| DE102019113039A1 (en) * | 2018-12-21 | 2020-06-25 | Carl Freudenberg Kg | arrangement |
| DE102019207241A1 (en) * | 2019-05-17 | 2020-11-19 | Zf Friedrichshafen Ag | Device for the electrically conductive connection between a shaft and a housing |
| WO2021115517A1 (en) | 2019-12-11 | 2021-06-17 | Schaeffler Technologies AG & Co. KG | Discharge device for discharging an electrical charge from a rotor of an electric motor |
| USD980069S1 (en) | 2020-07-14 | 2023-03-07 | Ball Corporation | Metallic dispensing lid |
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| WO2022187190A1 (en) | 2021-03-01 | 2022-09-09 | Ball Corporation | Metal container and end closure with seal |
| JP7604954B2 (en) | 2021-03-08 | 2024-12-24 | ニデック株式会社 | Rotating electric machine and drive unit |
| DE102021211082A1 (en) | 2021-10-01 | 2023-04-06 | Zf Friedrichshafen Ag | Arrangement for grounding a rotating shaft protruding from a housing |
| US11863027B2 (en) * | 2021-10-06 | 2024-01-02 | Abb Schweiz Ag | Reduction of shaft voltage |
| JP7698390B2 (en) | 2021-10-29 | 2025-06-25 | ニデック株式会社 | Rotating electric machine and drive unit |
| JP2023066951A (en) | 2021-10-29 | 2023-05-16 | ニデック株式会社 | Rotary electric machine and driving device |
| CN114221481B (en) * | 2021-11-18 | 2023-05-23 | 威睿电动汽车技术(宁波)有限公司 | Motor and vehicle |
| CN118679667A (en) * | 2022-01-27 | 2024-09-20 | (株)Hj通商 | Shaft grounding ring for preventing bearing from electric erosion |
| KR102474503B1 (en) * | 2022-08-18 | 2022-12-06 | (주)씨엔티솔루션 | Shaft grounding device, manufacturing method and application thereof |
| KR102576489B1 (en) * | 2022-09-07 | 2023-09-08 | 주식회사 어플라이드서멀 | Shaft grounding device, manufacturing method and application thereof |
| KR102800317B1 (en) * | 2023-04-03 | 2025-04-30 | 주식회사 인팩 | Shaft ground device of motor |
| KR102700552B1 (en) * | 2024-02-01 | 2024-08-30 | 유성기업 주식회사 | Shaft Ground Device For Electric Motor |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20040233592A1 (en) * | 2003-03-17 | 2004-11-25 | Oh Hieyoung W. | Grounding brush for mitigating electrical current on motor shafts |
| US20070040459A1 (en) * | 2005-08-17 | 2007-02-22 | Oh Hieyoung W | Shaft current control brush assembly with drainage |
| US20080083846A1 (en) * | 2006-10-10 | 2008-04-10 | Cedoz Roger T | Electrical connections for coating material dispensing equipment |
| US8199453B2 (en) * | 2003-03-17 | 2012-06-12 | Illinois Tool Works Inc. | Shaft current control brush ring assembly |
Family Cites Families (66)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2269614A (en) * | 1938-07-30 | 1942-01-13 | Zahnradfabrik Friedrichshafen | Sliding current collector for slip rings |
| US3286069A (en) | 1965-08-12 | 1966-11-15 | Kendick Mfg Company | Rotary electrical contact assembly |
| JPS50488B1 (en) * | 1970-05-15 | 1975-01-09 | ||
| US3997224A (en) * | 1973-12-26 | 1976-12-14 | Nissan Motor Co., Ltd. | Electrical contacting device |
| FR2404936A1 (en) * | 1977-10-03 | 1979-04-27 | Anvar | IMPROVEMENTS TO ELECTRIC SLIDING CONTACT DEVICES |
| US4189702A (en) * | 1978-09-25 | 1980-02-19 | Lowrance Electronics, Inc. | Commutator and fiber brush rotating disc |
| US4246508A (en) * | 1978-12-22 | 1981-01-20 | Skil Corporation | Brush holder assemblies for small electric motors |
| FR2469813A1 (en) * | 1979-11-08 | 1981-05-22 | France Etat | MULTI-FILAMENTARY BROOM SLIDING ELECTRIC CONTACT DEVICE |
| ZA8233B (en) * | 1981-01-15 | 1982-11-24 | Lucas Industries Ltd | Sliding contact assemblies for rotary electric machines |
| JPS5981254U (en) | 1982-11-24 | 1984-06-01 | 三菱電機株式会社 | Grounding device for preventing galvanic corrosion of rotating electrical machine bearings |
| US4575102A (en) | 1984-11-20 | 1986-03-11 | Ferrofluidics Corporation | Coaxial, multiple-shaft ferrofluid seal apparatus |
| FR2577722B3 (en) | 1985-02-21 | 1987-03-06 | Tubes Lampes Elect Cie Indle | MULTIFILAR LINE PROTECTION MODULE AGAINST OVERVOLTAGES |
| GB8531212D0 (en) | 1985-12-18 | 1986-01-29 | Lynch C | Electrical machines |
| US4685021A (en) | 1986-03-20 | 1987-08-04 | Juri Kortschinski | Fault current diverter |
| EP0262042B1 (en) * | 1986-09-23 | 1992-04-08 | Jaeger | Electrical transmission ring mounted between the steering shaft and the steering wheel of an automotive vehicle |
| CA1269693A (en) | 1987-05-13 | 1990-05-29 | Robert Ross Hamilton | Explosion-proof electrical generator system |
| JPH0448134Y2 (en) * | 1987-05-29 | 1992-11-12 | ||
| US4894785A (en) | 1987-09-18 | 1990-01-16 | Fernandes Roosevelt A | High voltage conductor mounted line powered monitoring system |
| US4801270A (en) * | 1987-10-05 | 1989-01-31 | Xerox Corporation | Shaft mounting and electrical grounding device |
| US5010441A (en) * | 1990-01-24 | 1991-04-23 | Xerox Corporation | Grounding brush |
| US5967524A (en) | 1993-05-21 | 1999-10-19 | Jm Clipper Corporation | Hybrid seal device |
| US6386546B1 (en) | 1993-05-21 | 2002-05-14 | Jm Clipper Corporation | Seal cartridge |
| US5661356A (en) * | 1993-10-22 | 1997-08-26 | Fisher; Rodney R. | Motor shaft discharge device |
| KR0178154B1 (en) | 1995-06-16 | 1999-05-15 | 정몽원 | Ac generator |
| GB9525212D0 (en) * | 1995-12-09 | 1996-02-07 | Rolls Royce Plc | Brush seal |
| US5799905A (en) | 1996-02-13 | 1998-09-01 | Rokita; Stephen R. | Apparatus and method for attaching gutters to structures |
| AU3690697A (en) | 1996-08-05 | 1998-02-25 | A.W. Chesterton Company | Seal/bearing assembly |
| US5812908A (en) * | 1997-03-25 | 1998-09-22 | Xerox Corporation | Carbon fiber electrical contact mounting for rotating elements |
| GB2324913A (en) * | 1997-04-02 | 1998-11-04 | Aisin Seiki | Magnetic shielding in high speed turbo alternator/motor |
| US5988996A (en) * | 1997-11-05 | 1999-11-23 | Baker Hughes Incorporated | Electrical shaft grounding brush assembly and holder for a submersible pump motor |
| US6419233B2 (en) | 1998-08-25 | 2002-07-16 | Isotech Of Illinois, Inc. | Shaft seal assembly |
| DE19845889B4 (en) | 1998-10-06 | 2007-03-01 | Dehn + Söhne GmbH + Co KG | The spark gap arrangement |
| US6145843A (en) | 1998-10-19 | 2000-11-14 | Stein Seal Company | Hydrodynamic lift seal for use with compressible fluids |
| JP2000245102A (en) * | 1999-02-22 | 2000-09-08 | Sawafuji Electric Co Ltd | DC motor |
| US6673216B2 (en) | 1999-08-31 | 2004-01-06 | Semitool, Inc. | Apparatus for providing electrical and fluid communication to a rotating microelectronic workpiece during electrochemical processing |
| US7212391B2 (en) | 1999-09-28 | 2007-05-01 | Rockwell Automation Technologies, Inc. | Grounded isolation system |
| US6390477B1 (en) | 1999-10-14 | 2002-05-21 | Garlock Inc | Rotary shaft bearing isolator seal |
| DE19956656A1 (en) | 1999-11-25 | 2001-05-31 | Moeller Gmbh | Current-limited contact arrangement has current loops in planes parallel to central plane and near contact opening path, and quenching plates held in two-part cassette of insulating material |
| JP2001320849A (en) | 2000-02-29 | 2001-11-16 | Asmo Co Ltd | Motor |
| US6984906B1 (en) * | 2000-07-13 | 2006-01-10 | General Electric Company | Bearing current reduction assembly |
| JP4538916B2 (en) * | 2000-07-31 | 2010-09-08 | パナソニック株式会社 | Ultrasonic transducer drive motor apparatus and ultrasonic diagnostic apparatus using the same |
| US6913265B2 (en) * | 2000-08-09 | 2005-07-05 | Advanced Components & Materials, Inc. | Brush seal assembly, method of manufacture and use |
| US20020121821A1 (en) * | 2001-03-02 | 2002-09-05 | Ritter Allen Michael | Method and apparatus for reducing bearing current in a motor and/or generator |
| US6670733B2 (en) | 2001-09-27 | 2003-12-30 | Reliance Electric Technologies, Llc | System and method of reducing bearing voltage |
| US7071589B2 (en) * | 2001-11-06 | 2006-07-04 | Precor Incorporated | Method and system for reducing bearing fluting in electromechanical machine |
| DE10154193A1 (en) | 2001-11-07 | 2003-05-15 | Zf Lemfoerder Metallwaren Ag | sleeve joint |
| US7396017B2 (en) | 2002-06-21 | 2008-07-08 | Isotech Of Illinois, Inc. | Shaft seal assembly |
| US7090403B2 (en) | 2002-06-21 | 2006-08-15 | Isotech Of Illinois, Inc. | Articulated seal |
| JP2004040926A (en) | 2002-07-04 | 2004-02-05 | Minebea Co Ltd | Fan motor |
| DE10239517A1 (en) * | 2002-08-28 | 2004-03-11 | Dürr Systems GmbH | Coating device with a rotary atomizer and method for controlling its operation |
| US7136271B2 (en) * | 2003-03-17 | 2006-11-14 | Illinois Tool Works Inc | Static charge neutralizing assembly for use on rollers and shafts |
| US7619861B2 (en) | 2004-09-29 | 2009-11-17 | Pass & Seymour, Inc. | Protective device having a thin construction |
| JP2006118552A (en) * | 2004-10-20 | 2006-05-11 | Mitsubishi Heavy Ind Ltd | Bearing device |
| CN101151780B (en) * | 2005-04-20 | 2011-06-29 | 伊利诺斯器械工程公司 | Shaft current control brush ring device |
| US7521827B2 (en) * | 2005-06-25 | 2009-04-21 | Isotech Of Illinois, Inc. | Motor ground seal |
| US8604653B2 (en) * | 2005-06-25 | 2013-12-10 | Inpro/Seal, LLC | Current diverter ring |
| US20070159017A1 (en) | 2006-01-11 | 2007-07-12 | Martin Jerry L | Explosion-proof motor with integrated sensor/lead housing |
| US7339777B2 (en) * | 2006-01-12 | 2008-03-04 | Illinois Tool Works Inc | Grounding system for a rotating shaft |
| EP1967774A1 (en) | 2007-03-05 | 2008-09-10 | Chugai High Technology Co., Ltd. | Coaxial multi-shaft assemblies |
| JP2008245385A (en) * | 2007-03-27 | 2008-10-09 | Brother Ind Ltd | Resolver fixing structure, sewing machine equipped with the resolver fixing structure |
| US8189317B2 (en) * | 2007-04-23 | 2012-05-29 | Illinois Tool Works Inc. | Grounding brush system for mitigating electrical current on rotating shafts |
| US8421286B2 (en) * | 2008-07-03 | 2013-04-16 | Nidec Motor Corporation | Kit and method for attaching a grounding ring to an electrical motor |
| US8183727B2 (en) * | 2008-11-24 | 2012-05-22 | Caterpillar Inc. | Grounding mechanism for electric motor |
| US8482173B2 (en) | 2009-01-14 | 2013-07-09 | Regal Beloit America, Inc. | End shield and inner bearing cap assembly |
| TW201108531A (en) * | 2009-04-09 | 2011-03-01 | Inpro Seal Llc | Current diverter ring |
| WO2013086531A1 (en) | 2011-12-08 | 2013-06-13 | Inpro/Seal Llc | Current diverter ring |
-
2011
- 2011-04-18 US US13/089,017 patent/US8604653B2/en active Active
-
2012
- 2012-04-18 WO PCT/US2012/034139 patent/WO2012145445A2/en active Application Filing
- 2012-04-18 MX MX2013012217A patent/MX2013012217A/en unknown
- 2012-04-18 BR BR112013027003A patent/BR112013027003A2/en not_active Application Discontinuation
- 2012-04-18 JP JP2014506525A patent/JP6163480B2/en active Active
- 2012-04-18 KR KR1020137030484A patent/KR101970367B1/en active Active
- 2012-04-18 EP EP12774863.0A patent/EP2710693A4/en not_active Withdrawn
- 2012-04-18 CN CN201280023972.1A patent/CN103548219B/en active Active
- 2012-04-18 CA CA2833565A patent/CA2833565A1/en not_active Abandoned
-
2013
- 2013-10-31 US US14/068,806 patent/US9525327B2/en not_active Expired - Fee Related
-
2016
- 2016-11-14 US US15/351,213 patent/US20170077663A1/en not_active Abandoned
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20040233592A1 (en) * | 2003-03-17 | 2004-11-25 | Oh Hieyoung W. | Grounding brush for mitigating electrical current on motor shafts |
| US8199453B2 (en) * | 2003-03-17 | 2012-06-12 | Illinois Tool Works Inc. | Shaft current control brush ring assembly |
| US20070040459A1 (en) * | 2005-08-17 | 2007-02-22 | Oh Hieyoung W | Shaft current control brush assembly with drainage |
| US20080083846A1 (en) * | 2006-10-10 | 2008-04-10 | Cedoz Roger T | Electrical connections for coating material dispensing equipment |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2020194191A1 (en) * | 2019-03-25 | 2020-10-01 | Troy Lance Timm | Grounding device |
| CN114382867A (en) * | 2020-10-06 | 2022-04-22 | 采埃孚股份公司 | Shaft grounding assemblies, transmissions and trolley drives |
Also Published As
| Publication number | Publication date |
|---|---|
| BR112013027003A2 (en) | 2016-12-27 |
| US8604653B2 (en) | 2013-12-10 |
| WO2012145445A3 (en) | 2013-01-10 |
| US20140191630A1 (en) | 2014-07-10 |
| CA2833565A1 (en) | 2012-10-26 |
| CN103548219A (en) | 2014-01-29 |
| KR20140023996A (en) | 2014-02-27 |
| KR101970367B1 (en) | 2019-04-18 |
| JP2014512798A (en) | 2014-05-22 |
| WO2012145445A2 (en) | 2012-10-26 |
| MX2013012217A (en) | 2014-10-14 |
| CN103548219B (en) | 2017-02-15 |
| JP6163480B2 (en) | 2017-07-12 |
| EP2710693A2 (en) | 2014-03-26 |
| US20110193446A1 (en) | 2011-08-11 |
| US9525327B2 (en) | 2016-12-20 |
| EP2710693A4 (en) | 2016-06-22 |
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