Patent Description:
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. Often the use of VFDs causes 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 <NUM> up to <NUM> and is referred to as the "carrier frequency. " The ratio of change in voltage to the change in time (ΔV/ΔT) 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 often referred to as "bearing current.

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.

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.

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, <CIT> 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.

<CIT> describes a current diverter ring comprising an inner body, said inner body comprising a main aperture, a radial channel fashioned in one face of said inner body, and a ridge fashioned on the exterior radial surface of said main body. The current diverter ring also comprises an outer body, said outer body comprising a base, an annular groove fashioned in the radial interior surface of said base, wherein said annular groove is defined by a first annular shoulder and a second annular shoulder, a radial projection, wherein said radial projection extends radially inward from said base, wherein a main aperture is formed in said radial projection, and wherein said outer body and said inner body are configured such that the engagement of said ridge with said annular groove secures said inner body to said outer body in the axial direction. The current diverter ring also comprises a conductive segment, wherein said conductive segment is positioned in said radial channel. In one example, a multi-ring current diverter ring includes a retainer with which at least two rings are secured. The retainer may be substantially ring-shaped with a retainer main aperture in the center thereof, which retainer main aperture corresponds to each ring main aperture. The retainer may be formed with a plurality of annular grooves and the rings may be formed with a plurality of radial channels. A conductive segment may be positioned in each radial channel. A shaft passes through a main aperture of the current diverter ring.

<CIT> describes how, in a steam turbine-generator system wherein the turbine shaft is subject to an electrostatic charge build-up, an active grounding system continuously maintains the shaft at substantially ground potential. A feedback circuit is connected between two brushes contacting the rotating shaft and is operable to generate a current of a magnitude to prevent electrostatic discharge as a function of the voltage as sensed by one of the brushes. A current sensor monitors the current supplied by the feedback circuit to the shaft and the output of the current sensor is utilized to diagnose various operating conditions of the steam turbine-generator system.

It is 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 <NUM> (also referred to as <NUM> 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 (<NUM> ohms-cmil/ft @ <NUM> F or <NUM> microhm-cm @ <NUM> C) and high electrical conductivity (<NUM>% IACS @ <NUM> F or <NUM> MegaSiemens/cm @ <NUM> 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).

According to a first aspect of the invention there is provided a current divider ring according to claim <NUM>. According to a second aspect of the invention there is provided a method for determining electrical contact using a current diverter ring according to claim <NUM>.

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.

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. 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 <NUM>, radial CDR <NUM>, multi-ring CDR <NUM>, and adaptable CDR <NUM> may be used interchangeably when referring to generalities of configuration with a bearing isolator <NUM>, methods and/or materials of construction, and/or other general features unless explicitly stated otherwise.

An equipment housing <NUM> with which a CDR <NUM> may be used is shown in <FIG>. The CDR <NUM> may be press-fit into an aperture in the equipment housing <NUM>, or it may be secured to the exterior of the equipment housing <NUM> using straps <NUM> and fasteners <NUM> as described in detail below and as shown in <FIG>. The CDR <NUM> may also be secured to an equipment housing <NUM> 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 <NUM> may also be configured to be engaged with a bearing isolator <NUM>, or integrally formed with a bearing isolator <NUM>, as described in detail below.

<FIG> illustrates a perspective view of a bearing isolator <NUM> configured to discharge electrical impulses from the shaft <NUM> through the equipment housing <NUM>. The bearing isolator <NUM> as shown in <FIG> may be mounted to a rotatable shaft <NUM> on either one or both sides of the equipment housing <NUM>. The bearing isolator <NUM> may be flange-mounted, press-fit (as shown in <FIG>), or attached to the equipment housing <NUM> using any other method and/or structure suitable for the particular application, as was described above for the CDR <NUM>. In some examples, set screws (not shown) or other structures and/or methods may be used to mount either the stator <NUM> to the equipment housing <NUM> or the rotor <NUM> to the shaft <NUM>. In another example not pictured herein, the shaft <NUM> is stationary and the equipment housing <NUM> or other structure to which the bearing isolator <NUM> is mounted may rotate.

The CDR <NUM> and/or bearing isolator <NUM>, neither of which is part of the present invention, may be mounted such that either the CDR <NUM> and/or bearing isolator <NUM> are allowed to float in one or more directions. For example, in one embodiment a portion of the bearing isolator <NUM> is positioned in an enclosure. The enclosure is fashioned as two opposing plates with main apertures therein, through which main apertures the shaft passes <NUM>. The interior of the enclosure is fashioned such that the bearing isolator <NUM> and/or CDR <NUM> is positioned within a truncated circle (i.e., pill-shaped) recess on the interior of the enclosure. The contact points between the bearing isolator <NUM> and/or CDR <NUM> and the enclosure may be formed with a low friction substance, such as Teflon®, affixed thereto.

A more detailed cross-sectional view of a bearing isolator <NUM> with which the CDR <NUM> may be used is shown in <FIG>. The bearing isolator <NUM> shown in <FIG> and <FIG> includes a stator <NUM> and a rotor <NUM>, 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 <CIT>; <CIT>; <CIT>; <CIT>; <CIT>; and <CIT>; and <CIT>.

The stator <NUM> may be generally comprised of a stator main body <NUM> 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 <FIG> and <FIG>, the stator <NUM> is fixedly mounted to an equipment housing <NUM> with an <NUM>-ring <NUM> forming a seal therebetween.

The rotor <NUM> may be generally comprised of a rotor main body <NUM> 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 <NUM> cooperates with a rotor axial groove <NUM>, and one rotor axial projection <NUM> cooperates with a stator axial groove <NUM> to form a labyrinth passage between the interior portion of the bearing isolator <NUM> and the external environment. The rotor <NUM> may be fixedly mounted to a shaft <NUM> and rotatable therewith. An <NUM>-ring <NUM> may be used to form a seal therebetween. A sealing member <NUM> may be positioned between the stator <NUM> and rotor <NUM> on an interior interface therebetween to aide in prevention of contaminants entering the interior of the bearing isolator <NUM> from the external environment while simultaneously aiding in retention of lubricants in the interior of the bearing isolator <NUM>.

In the bearing isolator <NUM>, not being part of the present invention, shown in <FIG> and <FIG>, one stator radial projection <NUM> provides an exterior groove in the stator <NUM> for collection of contaminants. A first axial interface gap 34a may be formed between the radially exterior surface of a stator radial projection <NUM> and the radially interior surface of a rotor radial projection <NUM>. A first radial interface gap 34b may be formed between the axially exterior surface of a stator axial projection <NUM> and the axially interior surface of a rotor axial groove <NUM>. A rotor axial projection <NUM> formed with a rotor radial projection <NUM> may be configured to fit within a stator axial groove <NUM> to provide another axial interface gap between the stator <NUM> and the rotor <NUM>.

In the bearing isolator <NUM> pictured herein, one rotor radial projection <NUM> (adjacent the rotor axial exterior surface <NUM>) extends radially beyond the major diameter of the stator axial projection <NUM>. This permits the rotor <NUM> to encompass the stator axial projection <NUM>. As is fully described in <CIT>, this radial extension is a key design feature of the bearing isolator <NUM> shown herein. The axial orientation of the first axial interface gap 34a controls entrance of contaminants into the bearing isolator <NUM>. Reduction or elimination of contaminants improves the longevity and performance of the bearing isolator <NUM>, bearing <NUM>, and conductive segment(s) <NUM>. The opening of the first axial interface gap 34a faces rearward, toward the equipment housing <NUM> and away from the contaminant stream. The contaminant or cooling stream will normally be directed along the axis of the shaft <NUM> and toward the equipment housing <NUM>.

To facilitate the discharge of electric energy on or adjacent the shaft <NUM>, the bearing isolator <NUM> may include at least one conductive segment <NUM> positioned within the stator <NUM>. The stator <NUM> may be configured with a conductive segment retention chamber adjacent the bearing <NUM>, in which conductive segment retention chamber the conductive segment <NUM> may be positioned and secured such that the conductive segment <NUM> is in contact with the shaft <NUM>. As electrical charges accumulate on the shaft <NUM>, the conductive segment <NUM> serves to dissipate those charges through the bearing isolator <NUM> and to the equipment housing <NUM>. The specific size and configuration of the conductive segment retention chamber will depend on the application of the bearing isolator <NUM> and the type and size of each conductive segment <NUM>. 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 <NUM>, such as those described for the CDR <NUM> shown in <FIG> or as described for the radial CDR <NUM>, shown in <FIG>.

The bearing isolator <NUM> is formed with a receptor groove <NUM>. The receptor groove <NUM> may be fashioned on the inboard side of the bearing isolator <NUM> adjacent the shaft <NUM>, as best shown in <FIG>. Generally, the receptor groove <NUM> facilitates the placement of a CDR <NUM> within the bearing isolator <NUM>. However, other structures may be positioned within the receptor groove <NUM> depending on the specific application of the bearing isolator <NUM>.

As shown and described, the bearing isolator <NUM> in <FIG> and <FIG> includes a plurality of radial and axial interface passages between the stator <NUM> and the rotor <NUM> resulting from the cooperation of the stator projections <NUM>, <NUM> with rotor grooves <NUM> and the cooperation of rotor projections <NUM>, <NUM> with stator grooves <NUM>. 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 the stator <NUM> and/or rotor <NUM> are in no way limiting. The bearing isolator <NUM> as disclosed herein may be used with any configuration stator <NUM> and/or rotor <NUM> wherein the stator <NUM> may be configured with a conductive segment retention chamber for retaining at least one conductive segment <NUM> therein or a receptor groove <NUM> as described in detail below.

A first current diverter ring (CDR) <NUM>, not being part of the present invention, is shown in perspective in <FIG>, and <FIG> provides an axial view thereof. The CDR <NUM> 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 CDR <NUM> is designed to be positioned between an equipment housing <NUM> and a shaft <NUM> protruding from the equipment housing <NUM> and rotatable with respect thereto.

Generally, the CDR <NUM> is comprised of a CDR body <NUM>, which may be fixedly mounted to the equipment housing <NUM>. A first wall <NUM> and a second wall <NUM> extend from the CDR body <NUM> and define an annular channel <NUM>. At least one conductive segment <NUM> is fixedly retained in the annular channel <NUM> so that the conductive segment <NUM> is in contact with the shaft <NUM> so as to create a low impedance path from the shaft <NUM> to the equipment housing <NUM>.

A cross-sectional view of the CDR <NUM> is shown in <FIG>. As shown in <FIG>, the axial thickness of the first wall <NUM> is less than that of the second wall <NUM>. The conductive segment <NUM> is retained within the annular channel <NUM> by first positioning the conductive segment <NUM> within the annular channel <NUM> and then deforming the first wall <NUM> to reduce the clearance between the distal ends of the first and second walls <NUM>, <NUM>. Deforming the first wall <NUM> in this manner retains the conductive segment <NUM> within the annular channel <NUM>. Depending on the material used for constructing the conductive segment <NUM>, the deformation of the first wall <NUM> may compress a portion of the conductive segment <NUM> to further secure the position of the conductive segment <NUM> with respect to the shaft <NUM>.

A detailed view of the CDR radial exterior surface <NUM> is shown in <FIG>. The CDR radial exterior surface <NUM> may be configured with a slight angle in the axial dimension so that the CDR <NUM> may be press-fit into the equipment housing <NUM>. The angle is one degree, but may be more or less in other examples not pictured herein. Also, the first wall <NUM> is positioned adjacent the bearing <NUM> when the CDR <NUM> is installed in an equipment housing <NUM>. However, in other examples not shown herein, the second wall <NUM> may be positioned adjacent the bearing <NUM> when the CDR <NUM> is installed in an equipment housing <NUM>, in which case the angle of the CDR radial exterior surface <NUM> would be opposite of that shown in <FIG>. The optimal dimensions/orientation of the CDR body <NUM>, annular channel <NUM>, first wall <NUM>, second wall <NUM>, and CDR radial exterior surface <NUM> will vary depending on the specific application of the CDR <NUM> and are therefore in no way limiting to the scope of the CDR <NUM>.

As was true for the bearing isolator <NUM>, a CDR <NUM> 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 CDRs disclosed herein, which do not have an annular channel <NUM> and the attending difficulties, are preferred.

In other CDRs <NUM> described in detail below, the CDR <NUM> is mounted to the equipment housing <NUM> using mounting apertures <NUM>, straps <NUM>, and fasteners <NUM> fashioned in either the CDR <NUM> or equipment housing <NUM>. The CDR <NUM> may be mounted to the equipment housing <NUM> by any method using any structure suitable for the particular application.

In the CDR <NUM> shown in <FIG> and <FIG>, three conductive segments <NUM> are positioned within the annular channel <NUM>. The optimal number of conductive segments <NUM> and the size and/or shape of each conductive segment <NUM> will vary depending on the application of the CDR <NUM>, and is therefore in no way limiting. The optimal total length of all conductive segments <NUM> and the total surface area of the conductive segments <NUM> that are in contact with the shaft <NUM> will vary from one application to the next, and is therefore in no way limiting to the scope of the CDR <NUM> or of a bearing isolator <NUM> configured with conductive segments <NUM> (such as the bearing isolator shown in <FIG> and <FIG>).

As shown in <FIG>, the CDR <NUM> may be sized to be engaged with a bearing isolator <NUM> having a receptor groove <NUM>, such as the bearing isolator <NUM> shown in <FIG> and <FIG>. As described above, <FIG> and <FIG> show a bearing isolator <NUM> fashioned to engage a CDR <NUM>. The receptor groove <NUM> may be formed as a recess in the stator <NUM> that is sized and shaped to accept a CDR <NUM> similar to the one shown in <FIG>, or other CDRs <NUM> disclosed herein. The CDR <NUM> may be press-fit into the receptor groove <NUM>, or it may be affixed to the stator <NUM> by any other method or structure that is operable to fixedly mount the CDR <NUM> to the stator <NUM>, including but not limited to set screws, welding, etc. When the CDR <NUM> is properly engaged with the receptor groove <NUM> in the stator <NUM>, the CDR radial exterior surface <NUM> abuts and contacts the interior surface of the receptor groove <NUM>.

In any of the CDRs <NUM> or bearing isolators <NUM> employing conductive segments <NUM>, the conductive segment <NUM> may be constructed of carbon, which is conductive and naturally lubricious. In one the conductive segment <NUM> is constructed of a carbon mesh manufactured by Chesterton and designated <NUM>-<NUM>. In other examples the conductive segment <NUM> has no coating on the exterior of the carbon mesh. When mesh or woven materials are used to construct the conductive segments <NUM>, often the surface of the conductive segment <NUM> that contacts the shaft <NUM> becomes frayed or uneven, which may be a desirable quality to reduce rotational friction in certain applications. Shortly after the shaft <NUM> has been rotating with respect to the conductive segments <NUM>, certain examples of the conductive segments <NUM> will wear and abrade from the surface of the shaft <NUM> so that friction between the conductive segments <NUM> and the shaft <NUM> is minimized. The conductive segments <NUM> may be fibrous, solid, or other material without limitation.

In general, it may be desirable to ensure that the impedance from the shaft <NUM> to the equipment housing <NUM> is in the range of <NUM> to <NUM> ohms to ensure that electrical charges that have accumulated on the shaft <NUM> are discharged through the equipment housing <NUM> and to the base of the motor (not shown) rather than through the bearing(s) <NUM>. The impedance from the shaft <NUM> to the equipment housing <NUM> may be decreased by ensuring the fit between the bearing isolator <NUM> and equipment housing <NUM>, bearing isolator <NUM> and CDR <NUM>, and/or CDR <NUM> and equipment housing <NUM> has a very small tolerance. Accordingly, the smaller the gap between the bearing isolator <NUM> and equipment housing <NUM>, bearing isolator <NUM> and CDR <NUM>, and/or CDR <NUM> and equipment housing <NUM>, the lower the impedance from the shaft <NUM> to the equipment housing <NUM>.

In other examples not pictured herein, conductive filaments (not shown) may be affixed to either the CDR <NUM> or bearing isolator <NUM> or embedded in conductive segments <NUM> affixed to either the CDR <NUM> or bearing isolator <NUM>. 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) <NUM> in the CDR <NUM> and/or bearing isolator <NUM>.

In another CDR <NUM> not pictured herein, the CDR <NUM> is affixed to the shaft <NUM> and rotates therewith. The first and second walls <NUM>, <NUM> of the CDR <NUM> extend from the shaft <NUM>, and the CDR main body <NUM> is adjacent the shaft <NUM>. The centrifugal force of the rotation of the shaft <NUM> causes the conductive segments <NUM> and/or conductive filaments to expand radially as the shaft <NUM> rotates. This expansion allows the conductive segments <NUM> and/or filaments to make contact with the equipment housing <NUM> even if grease or other contaminants and/or lubricants (which increase impedance and therefore decrease the ability of the CDR <NUM> to dissipate electrical charges from the shaft <NUM> to the equipment housing <NUM>) have collected in an area between the CDR <NUM> and the equipment housing <NUM>.

In another example not pictured herein, a conductive sleeve (not shown) may be positioned on the shaft <NUM>. This example is especially useful for a shaft <NUM> having a worn or uneven surface that would otherwise lead to excessive wear of the conductive segments <NUM>. 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 the shaft <NUM> to the conductive segments <NUM> in either the CDR <NUM> or a bearing isolator <NUM>. Another example that may be especially useful for use with shafts <NUM> having worn or uneven exterior surfaces is an example wherein conductive filaments or wires are inserted into the conductive segments <NUM>. These conductive filaments or wires may be sacrificial and fill in depressions or other asperities of the surface of the shaft <NUM>.

In another example not pictured herein, conductive screws (not shown) made of suitable conductive materials may be inserted into the conductive segments <NUM>. Furthermore, spring-loaded solid conductive cylinders may be positioned within the CDR <NUM> and/or bearing isolator <NUM> in the radial direction so as to contact the radial exterior surface of the shaft <NUM>.

Although elegant in its design, the CDR <NUM> shown in <FIG> is not the preferred example of the CDR <NUM>, as previously mentioned. Among other considerations, performance and manufacturing difficulties with this design dictate that other examples of the CDR <NUM> are more desirable. Particularly, the two-piece CDR <NUM> shown in <FIG> and described in detail below and the radial CDR <NUM> shown in <FIG> result in both of those examples being superior to that shown in <FIG>.

An illustrative example of a CDR <NUM>, not being part of the present invention, is shown in <FIG>. In the illustrative example of the CDR <NUM>, the CDR is formed from the engagement of an inner body <NUM> with an outer body <NUM>, which are shown disengaged but in relation to one another in <FIG>. The inner body <NUM> and outer body <NUM> in the illustrative example of the CDR <NUM> engage one another in a snapping, interference-type fit, which is described in detail below.

A perspective view of an inner body <NUM>, which may be generally ring shaped, is shown in <FIG>. The inner body <NUM> may include at least one radial channel <NUM> fashioned in an exterior face of the inner body <NUM>, which includes a main aperture <NUM> through which a shaft <NUM> may be positioned. The illustrative example pictured in <FIG> includes three radial channels <NUM>, but other examples may have a greater or lesser number of radial channels <NUM>, and therefore the number of radial channels in no way limits the scope of the CDR <NUM>. Each radial channel <NUM> may be formed with a catch 52a therein to more adequately secure certain types of conductive segments <NUM>. It is contemplated that a catch 52a will be most advantageous with conductive segments <NUM> made of a deformable or semi-deformable material (as depicted in <FIG>), but a catch 52a may be used with conductive segments <NUM> constructed of materials having different mechanical properties. The radial channels <NUM> as shown are configured to open toward a shaft <NUM> positioned in the main aperture <NUM>. The inner body <NUM> may be formed with a ridge <NUM> on the radial exterior surface thereof. The ridge <NUM> may be configured to engage the annular groove <NUM> formed in the outer body <NUM> as described in detail below.

The inner body <NUM> may be formed with one or more mounting apertures <NUM> therein. The illustrative example shown in <FIG> is formed with three mounting apertures <NUM>. Mounting fastener <NUM>, such as a screw or rivet, engaged with a mounting aperture <NUM>, as shown in <FIG> and <FIG>. The presence or absence of mounting apertures <NUM> will largely depend on the mounting method of the CDR <NUM>. For example, in the illustrative example shown in <FIG>, the inner body <NUM> does not include any mounting apertures <NUM>. It is contemplated that such examples will be optimal for use within a bearing isolator <NUM> and/or a CDR <NUM> that will be press fit into an equipment housing <NUM> or other structure.

A perspective view of an outer body <NUM>, which also may be generally ring shaped, is shown in <FIG>. The outer body <NUM> may be formed with a base <NUM> having an annular groove <NUM> formed on the radial interior surface thereof. The annular groove <NUM> may be defined by a first annular shoulder 64a and a second annular shoulder 65b. A radial projection <NUM> may extend radially inward from the base <NUM> adjacent either the first and/or second shoulder 65a, 65b. In the illustrative example pictured, the radial projection <NUM> is positioned adjacent the first annular shoulder 65a and includes a main aperture <NUM> therein, through which a shaft <NUM> may be positioned.

The annular groove <NUM> may be configured such that the ridge <NUM> formed in the inner body <NUM> engages the annular groove <NUM> so as to substantially fix the axial position of the inner body <NUM> with respect to the outer body <NUM>. As shown in <FIG>, and <FIG>, the ridge <NUM> may be slanted or tapered so that upon forced insertion of the inner body <NUM> in the outer body <NUM>, the ridge <NUM> slides past the second annular shoulder 65b and into the annular groove <NUM> to axially secure the inner body <NUM> and the outer body <NUM>. The engagement between the ridge <NUM> and the annular
groove <NUM> thereafter resists separation or dissociation of the inner and outer bodies <NUM>, <NUM>. In other examples not shown herein, the ridge <NUM> is not limited to a tapered configuration. The ridge <NUM> and base <NUM> may also be configured so an interference fit is created upon engagement to resist separation or disassociation of the inner and outer bodies <NUM>, <NUM>.

As shown in <FIG>, the inner body <NUM> and outer body <NUM> may be configured so that the interior periphery of the radial projection <NUM> has the same diameter as the interior periphery of the inner body <NUM> so that both the inner and outer bodies <NUM>, <NUM> have the same clearance from a shaft <NUM> when installed. It is contemplated that in most applications the CDR <NUM> will be installed so that the surface shown in <FIG> is axially exterior to the equipment housing <NUM> or other structure. However, if the CDR <NUM> is engaged with a bearing isolator <NUM>, the CDR <NUM> may be oriented such that the surface shown in <FIG> is facing toward the interior of the equipment housing <NUM> or other structure to which the bearing isolator <NUM> is mounted.

As shown in <FIG>, conductive segments <NUM> may be positioned in each radial channel <NUM>. It is contemplated that the radial channels <NUM> will be fashioned in the axial surface of the inner body <NUM> that is positioned adjacent the radial projection <NUM> of the outer body <NUM> when the CDR <NUM> is assembled, as shown in <FIG>. This orientation secures the axial position of the conductive segments <NUM>. As mentioned previously, a CDR <NUM> employing radial channels <NUM> for retention of conductive segments <NUM> is preferred as compared to a CDR <NUM> having an annular channel <NUM>. Typically, but depending on the materials of construction, the conductive segments <NUM> are sized so as to extend past the minor diameter of the inner body <NUM> into the main aperture <NUM> to contact the shaft <NUM>. The radial channels <NUM> are sized so as to not intersect the outer periphery of the inner body <NUM>. This prevents the conductive segment <NUM> from contacting the annular groove <NUM> of the outer body <NUM>.

The bearing isolator <NUM> and CDR <NUM> 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 <NUM> or bearing isolator <NUM> may be flange-mounted, press-fit, or attached to the equipment housing <NUM> by any other structure or method, such as through a plurality of straps <NUM> and fasteners <NUM>.

In certain applications, performance of the bearing isolator <NUM> may be improved by eliminating the O-rings <NUM> and their companion grooves fashioned in the stator <NUM> and the rotor <NUM>, as shown in <FIG> and <FIG>. The high-impedance nature of material used to construct the O-ring <NUM> (such as rubber and/or silicon) may impede conductivity between bearing isolator <NUM> and the equipment housing <NUM>, thereby decreasing the overall electrical charge dissipation performance of the bearing isolator <NUM>. However, if the O-rings <NUM> may be constructed of a low-impedance material, they may be included in any application of the CDR <NUM> and/or bearing isolator <NUM>. The optimal dimensions/orientation of the CDR <NUM>, inner body <NUM>, outer body <NUM>, and various features thereof will vary depending on the specific application of the CDR <NUM> and are therefore in no way limiting to the scope of the CDR <NUM>.

A radial CDR <NUM> is another illustrative example of a CDR <NUM>, which is shown in <FIG> as a ring-shaped structure having a main aperture <NUM> in the center thereof. As with other examples of the CDR <NUM> disclosed herein, the CDR <NUM> may be mounted to rotational equipment through any structure and/or method without limitation. The illustrative example of the radial CDR <NUM> shown in <FIG> includes three straps <NUM> affixed to the radial CDR <NUM> via fasteners <NUM>. Other fasteners <NUM> may be used to secure the straps <NUM> to the rotational equipment, thereby securing the radial CDR <NUM> to the rotational equipment. In other illustrative examples of the radial CDR <NUM>, the radial exterior surface 85a of the radial CDR <NUM> is press-fit into the rotational equipment housing <NUM>. However, the mounting method for the radial CDR is in no way limiting to its scope.

The illustrative example of the radial CDR <NUM> shown herein includes three radial channels <NUM> extending from the radial exterior surface 85a to the radial interior surface 85b. Each radial channel <NUM> may include a radial channel shelf <NUM>, which is best shown in <FIG>. In the pictured illustrative example, the radial channel shelf <NUM> is located adjacent the radial interior surface 85b of the radial CDR <NUM>.

A conductive assembly <NUM> may be configured to securely fit within the radial channel <NUM>. One illustrative example of a conductive assembly <NUM> is shown in detailed in <FIG>. The conductive assembly <NUM> may comprise a binder 86a that is primarily located within the radial channel <NUM> and a contact portion 86b that extends radially inward from the radial channel <NUM>. The binder 86a may be formed as any structure that retains the elements of the conductive assembly <NUM>, including but not limited to a chemical adhesive, structural cap or tether, or combinations thereof. Other types of conductive assemblies <NUM> may be used with the radial CDR <NUM> without limitation.

The conductive assemblies <NUM> in the radial CDR <NUM> may be configured to be replaceable. That is, once the contact portion 86b of a conductive assembly <NUM> has been exhausted, or the conductive assembly <NUM> should otherwise be replaced, the user may remove the conductive assembly <NUM> from the radial channel <NUM> and insert a new conductive assembly <NUM> therein.

A first illustrative example of a multi-ring CDR <NUM> is shown in <FIG>. This example of a multi-ring CDR <NUM> is similar to the two-piece CDR <NUM> described in detail above and shown in <FIG>. The multi-ring CDR <NUM> includes a retainer <NUM> with which at least two rings <NUM> are secured. The retainer <NUM> may be substantially ring-shaped with a retainer main aperture <NUM> in the center thereof, which retainer main aperture <NUM> corresponds to each ring main aperture <NUM>.

The retainer <NUM> may be formed with a plurality of annular grooves 112a, 112b, 112c, 112d on the radial interior surface of the retainer base <NUM> to provide seating surfaces for the various rings <NUM>. The example of the multi-ring CDR <NUM> shown herein includes a total of four rings <NUM> and four annular grooves <NUM>. However, other examples may be a greater or smaller number of rings <NUM> and corresponding annular grooves <NUM> without limiting the scope of the multi-ring CDR <NUM>.

The rings <NUM> may be formed with a plurality of radial channels <NUM> similar to those formed in the inner body <NUM> for the example of the CDR <NUM> shown in <FIG>. The radial channel <NUM> is typically formed on the interior axial surface 127a of the ring <NUM>. A conductive segment <NUM> may be positioned in each radial channel <NUM>. Additionally, each radial channel <NUM> may be formed with a catch 122a therein to better retain the conductive segment <NUM>.

A retainer wall <NUM> may extend radially inward from the first annular groove 112a toward the retainer main aperture <NUM>, which retainer wall <NUM> is analogous to the radial projection <NUM> of the outer body <NUM> for the CDR <NUM> embodiment shown in <FIG>. In the embodiments pictured herein, the retainer wall <NUM> is substantially perpendicular to the retainer base <NUM>. The retainer wall <NUM> may serve as a stop for the innermost ring <NUM> as shown in <FIG>. The interior axial surface 127a of the innermost ring <NUM> may abut the retainer wall <NUM>, thereby compressing the conductive segments <NUM> positioned in the radial channels <NUM> of the innermost ring <NUM> between the ring <NUM> and the retainer wall <NUM>. The ring radial exterior surface <NUM> of the innermost ring <NUM> may engage the first annular groove 112a in such a manner as to secure the innermost ring <NUM> to the retainer <NUM> via an interference fit.

The interior axial surface 127a of the ring <NUM> immediately exterior to the innermost ring <NUM> may abut the exterior axial surface 127b of the innermost ring <NUM>, thereby compressing the conductive segments <NUM> positioned in the radial channels <NUM> of that ring <NUM> between that ring <NUM> and the innermost ring <NUM>. The ring radial exterior surface <NUM> of the ring <NUM> immediately exterior to the innermost ring <NUM> may engage the second annular groove 112b in such a manner as to secure that ring <NUM> to the retainer via an interference fit. This is shown in detail in <FIG>. The arrangement may continue with all rings <NUM> engaged with the retainer <NUM>.

The outermost ring <NUM> may be configured with a ridge <NUM> on the ring radial exterior surface <NUM>. This ridge <NUM> may be angled upward from the interior axial surface 127a to the exterior axial surface 127b, such that the ridge <NUM> engages a snap groove <NUM> that may be formed in the outermost annular groove <NUM> (which is the fourth annular groove 112d in the example shown herein). Accordingly, the outermost ring <NUM> may be secured to the retainer <NUM>, thereby securing all other rings <NUM>, through the engagement of the ridge <NUM> with the snap groove <NUM>. This is analogous to the engagement of the inner body <NUM> with the outer body <NUM> via the ridge <NUM> and annular groove <NUM>, respectively located on the inner body <NUM> and outer body <NUM> for the CDR <NUM> shown in <FIG>.

In a split example multi-ring CDR <NUM>, not being part of the present invention, the rings <NUM> may be secured to the retainer <NUM> using fasteners, such as fasteners, as shown in <FIG>. The rings <NUM> in this example may be comprised of two ring segments <NUM>, and the retainer <NUM> may be formed as two separate pieces. The interaction between the innermost split ring segments <NUM> and the retainer <NUM> is analogous to that described above for the first example of the multi-ring CDR <NUM>. Furthermore, the interaction between adjacent split ring segments <NUM> and the corresponding retention of conductive segments <NUM> for the split multi-ring CDR <NUM> is analogous to that described for the first multi-ring CDR <NUM>. To retain the split ring segments <NUM>, an interference fit between the ring radial exterior surface <NUM> and individual annular grooves 112a, 112b, 112c, 112d in conjunction with a snap groove <NUM> in the outermost annular groove <NUM> and a ridge <NUM> in the outermost ring <NUM>. The interference fit securement mechanism may be employed alone or in combination with a plurality of fasteners <NUM>, or the plurality of fasteners <NUM> may be solely employed as a securement mechanism. If fasteners <NUM> are used, the ring segments <NUM> may be formed with apertures <NUM> to receive the fasteners <NUM>.

A backing ring <NUM> may be used with certain CDRs <NUM>, <NUM>, <NUM>, as shown in <FIG>. The backing ring <NUM> may also be formed of two distinct pieces, which pieces may be secured to one another through a plurality of corresponding alignment pin receptors <NUM>, fastener bores <NUM>, fastener receptors <NUM> and corresponding alignment pins <NUM> and fasteners <NUM>. In <FIG>, two alignment pins <NUM> and corresponding alignment pin receptors <NUM> are positioned at the seam of the backing ring <NUM> to properly align the two pieces. Two fasteners <NUM> may be placed in respective fastener bores <NUM> so that a portion of each fastener <NUM> engages a respective fastener receptor <NUM>, thereby securing the two pieces of the backing ring <NUM> to one another.

The backing ring <NUM> 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 <NUM> and corresponding alignment pins <NUM> and/or fastener bores <NUM> and corresponding fasteners <NUM> 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 ring main aperture <NUM> and <NUM>-ring channel <NUM> may be fashioned in the backing ring <NUM> to the desired specifications. Apertures <NUM> may be fashioned in the backing ring <NUM> per the user's requirements so that the perfectly or near perfectly circular backing ring <NUM> may be properly centered over a shaft or other structure.

An adaptable CDR <NUM>, not being part of the present invention, is shown in <FIG> and <FIG>. The adaptable CDR <NUM> 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 <NUM> that extend from the radial exterior surface 165a to the radial interior surface 165b adjacent the main aperture <NUM>. Like the radial channels <NUM> in the radial CDR <NUM>, the radial channels <NUM> in the adaptable CDR <NUM> may include a radial channel shelf <NUM>. Accordingly, a conductive assembly <NUM> may secured in each radial channel <NUM>.

It is contemplated that the user will drill and tap holes in the exterior of the rotational equipment such that a fastener <NUM> may pass through each of the slots <NUM> formed in the adaptable CDR <NUM>. The adaptable CDR <NUM> may include a plurality of recesses <NUM> to better accommodate differences in the exterior of various rotational equipment. The adaptable CDR <NUM> may have a cut out <NUM> protruding into the main aperture <NUM> to facilitate installation of the adaptable CDR <NUM> over a shaft or other object.

An arc CDR 80a, not being part of the present invention, is another example of a CDR <NUM>. A first example of an arc CDR 80a is shown in <FIG> as a semi-circular shaped structure having a main aperture <NUM> in the center thereof and an arc cut out <NUM>. <FIG> provides a perspective view of the first illustrative example of an arc CDR 80a positioned over a shaft <NUM>. <FIG> provides another perspective view of the first example of an arc CDR 80a without a shaft <NUM> for purposes of clarity. <FIG> provides a radial cross-sectional view of the arc CDR 80a shown in <FIG> & <FIG>. A perspective view of a second example of an arc CDR 80a shown positioned around a shaft <NUM> is shown in <FIG>. <FIG> provides another perspective view of this example of an arc CDR 80a with the shaft <NUM> removed in <FIG> is a radial cross-sectional view.

The arc CDR 80a as shown herein function substantially the same as the radial CDR <NUM> shown in <FIG>. However, because the arc CDR 80a is not a full ring (which the radial CDR <NUM> is) the arc CDR 80a may be easier to install over certain shafts <NUM> than the radial CDR <NUM> for specific applications in the same way the adaptable CDR <NUM> (shown in <FIG> and <FIG>) be easier to install than the radial CDR <NUM>. For certain arc CDRs 80a it may be beneficial to use a sleeve (not shown), plate (not shown) or other structure to properly position the arc CDR 80a with respect to the shaft <NUM>. It is contemplated that the arc CDR 80a shown in <FIG> may be engaged with the structure from which the shaft <NUM> extends via one or more mounting apertures <NUM> therein that may cooperate with a fastener <NUM>. It is contemplated that the arc CDR 80a shown in <FIG> may be engaged with the structure from which the shaft <NUM> extends via one or more straps <NUM> in cooperation with one or more fasteners <NUM>. However, any suitable structure and/or method for securing the arc CDR 80a to a structure may be used without limitation.

The arc CDR 80a pictured herein is configured such that the arc CDR 80a extends beyond <NUM> degrees of a circle. More specifically, the arc CDR 80a is approximately <NUM> degrees of a full circle. However, in other
examples the length of the arc CDR 80a may be greater than <NUM> degrees of a full circle. In still other examples, the length of the arc CDR 80a may be less than <NUM> degrees of a full circle.

The arc CDR 80a shown in <FIG> includes three radial channels <NUM> extending from the radial exterior surface 85a to the radial interior surface 85b. Each radial channel <NUM> may include a radial channel shelf <NUM>, which is best shown in <FIG>. The radial channel shelf <NUM> is located adjacent the radial interior surface 85b of the arc CDR 80a. The arc CDR 80a shown in <FIG> includes four radial channels <NUM> that may be so configured. A conductive assembly <NUM> may be configured to securely engage a radial channel <NUM>, and a plug <NUM> may be positioned over the conductive assembly <NUM> to secure the position of the conductive assembly <NUM>. A conductive assembly <NUM> is shown in detail in <FIG>. Other types of conductive assemblies <NUM> may be used with the arc CDR 80a without limitation. One embodiment of a plug <NUM> is threaded and cooperates with threads formed in a radial channel <NUM>, as shown in <FIG>.

The conductive assemblies <NUM> in the arc CDR 80a may be configured to be replaceable. That is, once the contact portion 86b of a conductive assembly <NUM> has been exhausted, or the conductive assembly <NUM> should otherwise be replaced, the user may remove the conductive assembly <NUM> (and/or plug <NUM> if one is used) from the radial channel <NUM> and insert a new conductive assembly <NUM> therein. The number of radial channels <NUM> formed in an arc CDR 80a in no way limits the scope thereof, and similarly, the number of conductive assemblies engaged therewith in no way limits the scope of an arc CDR 80a.

One embodiment of an intelligent CDR <NUM>' is shown in <FIG> & <FIG>. As shown, the illustrative embodiment of the intelligent CDR <NUM>' may be configured to alert the user when the intelligent CDR <NUM>' is no longer adequately diverting current from the shaft <NUM> to ground. The embodiment of the intelligent CDR <NUM>' shown herein accomplishes this in part through the use of an indicator conductive assembly <NUM>' engaged with an existing CDR <NUM> or integrated into an existing CDR <NUM>. In other embodiments, the intelligent CDR <NUM>' is incorporated into a separate structure adjacent an existing CDR <NUM>. Any CDR <NUM>, <NUM>, 80a, <NUM>, <NUM>, <NUM>, <NUM> may be configured for use as and/or with an intelligent CDR <NUM>' without limitation.

In the illustrative embodiment, the indicator conductive assembly <NUM>', shaft <NUM>, secondary conductive assembly <NUM>', and various electronics may be configured to constitute a circuit through which electricity may flow when the conductive assemblies <NUM>', <NUM>' are adequately contacting the shaft <NUM>. The indicator conductive assembly <NUM>' may be formed substantially in the same manner as other conductive assemblies <NUM> previously described herein, using an indicator binder and indicator contact portion 214b'. Similarly, the secondary conductive assembly <NUM>' may be formed with a secondary binder and secondary contact portion 216b'. However, any suitable structure and/or method for determining electrical contact between the indicator <NUM>', <NUM>' and the shaft <NUM> may be used with the intelligent CDR <NUM>' without limitation.

A power source <NUM>' and indicator <NUM>' may be incorporated into the circuit described above as one structure/method to alert the user as to when the conductive assembly <NUM> is no longer functioning properly. The power source <NUM>' and indicator <NUM>' may be incorporated in various manners to achieve this function. In one configuration, the power source <NUM>' is in electrical communication with the indicator <NUM>' (which comprises an LED light) via the indicator conductive assembly <NUM>', shaft <NUM>, and secondary conductive assembly <NUM>'. The power source <NUM>' causes the indicator <NUM>' to be active until the circuit is opened via the indicator conductive assembly <NUM>' or secondary conductive assembly <NUM>' no longer contacting the shaft <NUM> at their respective contact portions 214b', 216b' (i.e., upon failure of the CDR <NUM> to adequately divert current from the shaft <NUM> to ground). Accordingly, when the LED light (indicator <NUM>' in this embodiment) is no longer illuminated, the conductive assemblies <NUM> should be replaced.

In another embodiment, a switch may be positioned to be in electrical communication with the power source <NUM>' and the indicator <NUM>'. These elements may be configured such that when the user activates the switch , if the indicator conductive assembly <NUM>' and secondary conductive assembly <NUM>' are both adequately contacting the shaft <NUM>, the indicator <NUM>' will communicate that information. For example, if the indicator <NUM>' is configured as an LED light, the light may illuminate upon the user activating the switch. Alternatively, the indicator <NUM> may be configured as an auditory device, or a combination of visual and auditory devices. Accordingly, the intelligent CDR <NUM>' is not limited by the type of indicator <NUM> that may be used therewith, and any indicator <NUM>' that may be configured to alert the user as to whether the indicator conductive assembly <NUM>' and secondary conductive assembly <NUM>' are or are not adequately contacting the shaft <NUM>.

In another embodiment of the intelligent CDR <NUM>', the indicator <NUM>' may become active when the indicator conductive assembly <NUM>' and/or secondary conductive assembly <NUM>' no longer adequately contact the shaft <NUM>, which is opposite to the previously described embodiment. In an embodiment in which the indicator <NUM>' becomes active upon inadequate contact, either the indicator conductive assembly <NUM>' and/or secondary conductive assembly <NUM>' may be configured so that upon a certain amount of wear to the respective contact portions 214b', 216b', an ancillary member (not shown) contacts the shaft <NUM>. Upon contact of the ancillary member with the shaft <NUM>, the circuit containing the power source <NUM>' and indicator <NUM>' may become closed. Alternatively, a conductive member of a different configuration and/or dimensions (e.g., shorter) than that of the indicator conductive assembly <NUM>' and/or secondary conductive assembly <NUM>' may be positioned inside one of the conductive assemblies <NUM>', <NUM>' such that when the conductive member engages the shaft <NUM>, the indicator <NUM>' will become active.

The intelligent CDR <NUM>' may also be incorporated into a fastener <NUM> used to mount the CDR <NUM> to an equipment housing <NUM>. In such an embodiment of the intelligent CDR <NUM>', it may be required for that particular fastener <NUM> to be electrically isolated from any other fasteners <NUM> attached to the intelligent CDR <NUM>' to ensure proper functionality. In such an embodiment, the electrical discharges from the bearing <NUM> to the equipment <NUM> may cause the indicator <NUM>' to become active as those discharges pass through the fastener <NUM> engaged with the intelligent CDR <NUM>'.

These or other embodiments of the intelligent CDR <NUM>' may be equipped with other features. For example, a radio frequency identification tag ("RFID" tag, not shown) may be integrated into the circuitry of the intelligent CDR <NUM>'. The circuitry of the intelligent CDR <NUM>' may also include a micro-PLC, which may be configured to gather and record various data related to the intelligent CDR <NUM>', CDR <NUM>, bearing isolator <NUM>', and/or equipment. The RFID tag may simplify maintenance identification of the various equipment, intelligent CDRs <NUM>', CDR <NUM> and/or bearing isolators <NUM> at a given site.

In another embodiment of the intelligent CDR <NUM>', the circuitry thereof may include a microprocessor (not shown) to perform various functions related to the intelligent CDR <NUM>', bearing isolator <NUM>, and/or equipment. The microprocessor may be configured with a wireless communication module, such as Bluetooth, short wave radio frequency transponder, various <NUM> protocol devices, and/or any other suitable wireless communication system. If the intelligent CDR <NUM>' is so equipped, the system may be remotely monitored by a user or maintenance personnel. The intelligent CDR <NUM>' may simply communicate with a properly programmed CPU (not shown) either wired or wirelessly to relay and/or record operational data and alert the user to specific conditions. Other embodiments of the intelligent CDR <NUM>' may employ wireless communication ability without the use of a microprocessor.

One illustrative embodiment of a wireless embodiment of an intelligent CDR <NUM>' is shown in <FIG>. Those practiced in the arts will understand that there are an infinite number of implementation methods, operational parameters to monitor/record/relay, and/or uses for an intelligent CDR <NUM>' so configured. As shown, the sensor may be in communication with a transmitter. The transmitter may be configured to wirelessly communicate with a network node and/or other wireless device (e.g., smartphone, computer, etc.). That network node and/or other wireless device may be in communication with a local area network, wide area network, or any other communications network suitable for the particular application of the intelligent CDR <NUM>'. As shown, the sensor interface may be configured to communicate with the transmitter and/or the transmitter may be configured to communicate with the network node and/or other wireless device via any suitable protocol, including but not limited to IEEE <NUM>, IEEE <NUM>, BlueTooth, etc. As shown, the network and adaptor layer may include, but is not limited to a field bus, profibus, mod bus, can open, interbus, and/or device net.

Any other structure and/or methods that functions to alert the user when the conductive assemblies <NUM> no longer properly contact the shaft <NUM> may be used in the intelligent CDR <NUM>' without departing from the scope thereof irrespective of whether such structures and/or methods require an active step from the user to bring forth the alert (e.g., press a button, scan a frequency, etc.).

Various other electrical components that may be required to facilitate the operation of the intelligent CDR <NUM>', such as capacitors, resistors, transistors, etc. are not shown herein for purposes of clarity, and are in no way limiting to the scope of the intelligent CDR <NUM>'. All of the electrical components required to facilitate the intelligent CDR <NUM>' may be positioned in a cavity (not shown) formed within the body of a CDR <NUM> as described herein and/or bearing isolator <NUM>. Alternatively, the intelligent CDR <NUM>' and/or certain components thereof may be positioned in a shaft grounding device, shaft seal, or other structure suitable for rotating equipment not disclosed herein.

An illustrative example of a captured CDR <NUM>, not being part of the present invention, is shown in <FIG>. As with other examples of the CDR <NUM> disclosed herein, the captured CDR <NUM> may be mounted within a bearing isolator <NUM> or it may be mounted directly to equipment housing <NUM> using any structure and/or method disclosed herein for other CDRs <NUM>. The illustrative example utilizes an open face, as best shown in <FIG>, which provides a front perspective view of the captured CDR <NUM> fully assembled.

The main body <NUM> may include a base <NUM> extending along the axis of the main body main aperture <NUM> and a main body wall <NUM> extending perpendicular to the base <NUM>. In this example, the main body <NUM> includes a radial exterior surface 215a and a radial interior surface 215b. In a press-fit design, the radial exterior surface 215a directly abuts the equipment housing <NUM>. The main body wall <NUM> may be fashioned with one or more skate grooves <NUM> on the interior surface thereof. Skates <NUM>, which are generally comprised of ring-shaped, low-friction, and/or low-wear material, may be positioned in the skate grooves <NUM> to reduce the frictional losses between the main body <NUM> and the rotor body <NUM>, which is described in detail below. It is contemplated that some examples of skates <NUM> may be constructed of PTFE, but any suitable material may be used without limitation.

The rotor may be comprised of two separate units- a rotor body <NUM> and a rotor ring <NUM>. The rotor body <NUM> may also be substantially ring shaped with a base <NUM> and a rotor body main aperture <NUM> in the center thereof. A flange <NUM> may extend radially outward from the base <NUM>. A lock channel <NUM> may be formed on the radially exterior surface of the base <NUM> and a drive ring groove <NUM> may be formed on the radially interior surface of the base <NUM>. A drive ring <NUM> may be positioned within the drive ring groove <NUM> and fit securely around a shaft <NUM> that is positioned concentric with the rotor body main aperture <NUM>. The drive ring <NUM> may be configured to couple the rotor body <NUM> to the shaft <NUM> so that the rotor body <NUM> rotates with the shaft <NUM>. The drive ring <NUM> may be formed of any suitable material for the particular application, including but not limited to, woven carbon fibers, solid conductive segments, conductive polymers, and/or combinations thereof. Accordingly, the scope of the captured CDR <NUM> is not limited by the material chosen for the drive ring <NUM>.

The rotor ring <NUM> may also be ring-shaped with a rotor ring main aperture <NUM> formed substantially in the center thereof. The rotor ring <NUM> may be formed with a plurality of radial channels <NUM> on the interior axial surface 237a of the rotor ring <NUM>. Each radial channel <NUM> may be configured with a catch 232a to better retain conductive segments <NUM> as previously described for other examples of the CDR <NUM>. The interior axial surface 237a of the rotor ring <NUM> may be positioned to abut the interior surface of the flange <NUM> of the rotor body <NUM> when the captured CDR <NUM> is fully assembled, as best shown in <FIG>. The rotor ring <NUM> may also be formed with a ridge <NUM> around the periphery of the rotor ring main aperture <NUM>.

Distal ends of conductive segments <NUM> may be positioned in the radial channels <NUM>, and the rotor ring <NUM> may be pressed over the rotor body <NUM> base <NUM>. As the rotor ring <NUM> is pressed over the rotor body <NUM> base <NUM>, the ridge <NUM> on the rotor ring <NUM> may be configured to snap into the lock channel <NUM> formed in the rotor body <NUM> base <NUM> such that the rotor ring <NUM> and rotor body <NUM> are engaged with one another in such a manner that the rotor ring <NUM> rotates with the rotor body <NUM> (and, consequently, the shaft <NUM>). This may also engage the distal ends of the conductive segments <NUM> within the radial channels <NUM> formed in the rotor ring <NUM> between the rotor ring <NUM> and the flange <NUM> of the rotor body <NUM> such that the conductive segments <NUM> are properly retained.

In operation, the main body <NUM> is generally static, while the rotor body <NUM> and rotor ring <NUM> generally rotate with the shaft <NUM>. The main body wall <NUM>, radial interior surface 215a of the main body <NUM> base <NUM>, and the ring radial exterior surface <NUM> of the rotor ring <NUM> may cooperate to form a retention chamber <NUM> in which the non-distal ends of the conductive segments <NUM> may be positioned. The centrifugal force imparted to the conductive segments <NUM> due to the rotation of the rotor body <NUM> and rotor ring <NUM> may cause a portion of the conductive segments <NUM> to contact the radial interior surface 215a of the main body <NUM> base <NUM>. Accordingly, the drive ring <NUM> may conduct charges to the rotor body <NUM>, which may conduct charges to the rotor ring <NUM>, which may conduct charges to the conductive segments <NUM>, which may conduct charges to the main body <NUM> and subsequently to the equipment housing <NUM>.

In another illustrative example of the captured CDR <NUM>, which is shown in cross section in <FIG>, the rotor ring <NUM> includes a rotor ring flange <NUM> extending radially from the rotor ring <NUM> adjacent the exterior axial surface 237b of the rotor ring <NUM>. In this example, the rotor ring flange <NUM> cooperates with the other surfaces to close the retention chamber <NUM>, which may increase the longevity of the conductive segments <NUM> in various applications.

Another illustrative example of the captured CDR <NUM> is shown in <FIG>. In this example, the rotor is essentially comprised of a rotor ring <NUM>. The main body <NUM> may still include a base <NUM> terminating with a cap interface surface <NUM> and a main body wall <NUM> extending radially inward from the base <NUM>, which is shown in detail in <FIG>. The main body wall <NUM> may be configured with at least one skate groove <NUM> fashioned therein. Skates <NUM> may be positioned in the skate grooves <NUM> to reduce friction and/or wear between the moving parts, as previously described for other examples. The cap interface surface <NUM> may be fashioned with at least one receiver <NUM> for engaging the cap <NUM> with the main body <NUM>, which is described in detail below.

The rotor ring <NUM> in this example may be configured with at least one radial channel <NUM> extending from the ring radial exterior surface <NUM> to the rotor ring main aperture <NUM>. The rotor ring <NUM> is shown in detail in <FIG>. A segment groove <NUM> may be fashioned around the periphery of the rotor ring main aperture <NUM> between two adjacent radial channels <NUM>. Conductive segments <NUM> may be positioned so that the distal ends thereof extend through the radial channels <NUM> and the interior portions thereof are retained within the segment groove <NUM>. When assembled, the interior axial surface 237a of the rotor ring <NUM> may abut the main body wall <NUM>, as best shown in <FIG>, which provides an axial cross section of this example of the captured CDR <NUM> when assembled. The portion of the conductive segments <NUM> positioned in the segment groove <NUM> may be configured so as to engage the shaft <NUM> such that the rotor ring <NUM> rotates with the shaft <NUM>.

A generally ring-shaped cap <NUM> may be fashioned with a cap main aperture <NUM> substantially positioned in the geometric center of the cap <NUM>. The cap <NUM> may be formed with at least one skate groove <NUM> on the cap interior axial surface 247a as best shown in <FIG>, into which skates <NUM> may be positioned to reduce friction and/or wear as previously described. The cap <NUM> may be engaged with the main body <NUM> via a plurality of fasteners <NUM> passing through apertures <NUM> in the cap <NUM> and engaging corresponding receivers <NUM> fashioned in the main body <NUM>. When the cap <NUM> is engaged with the main body <NUM>, the main body wall <NUM>, the main body <NUM> radial interior surface 215b, and the axial interior surface 247a of the cap <NUM> may cooperate to form a retention chamber <NUM> in which a portion of each conductive segment <NUM> may be positioned.

As with other examples of the captured CDR <NUM>, in operation the main body <NUM> is generally static, while the rotor ring <NUM> generally rotates with the shaft <NUM>. The centrifugal force imparted to the conductive segments <NUM> due to the rotation of the rotor ring <NUM> may cause a portion of the conductive segments <NUM> to contact the radial interior surface 215a of the main body <NUM> base <NUM>. Accordingly, the conductive segments <NUM> may conduct charges from the shaft to the main body <NUM> and subsequently to the equipment housing <NUM>.

Certain illustrative examples of the explosion-proof CDR <NUM> may be configured to comply with ATEX <NUM> equipment directive <NUM>/<NUM>/EC and/or the standard UL <NUM> for explosion-proof and dust-ignition-proof electrical equipment. Such compliance may include the following certifications: (<NUM>) UL ClassI/II Division <NUM>; (<NUM>) ATEX EX Group II, Equipment Category <NUM> (G, Zone <NUM>; D, Zone <NUM>); and, (<NUM>) Mining Certification, Equipment Category ½ and Zones <NUM>, <NUM>/<NUM>, <NUM>. Mounting such an example of an explosion-proof CDR <NUM> to an explosion-proof certified motor will create an explosion-proof certified system without the need for additional testing and/or certification. However, the explosion-proof CDR <NUM> is in no way limited by the specific certifications, standards, and/or certification body.

A first illustrative example of an explosion-proof CDR <NUM> is shown in <FIG>. The first illustrative example of an explosion-proof CDR <NUM> may be configured to engage a housing (not shown).

via one or more fasteners <NUM> passing through corresponding apertures formed in the cap flange <NUM>. As described for the bearing isolators <NUM> and other CDRs <NUM>, <NUM>, 80a, <NUM>, <NUM>, <NUM>, and/or captured CDR <NUM>, any suitable mounting structure(s) and/or method(s) may be used with any example of the explosion-proof CDR <NUM> without limitation. Accordingly, the specific structure and/or method for properly mounting an explosion-proof CDR <NUM> in no way limits the scope thereof as disclosed herein.

Referring now to <FIG> and <FIG>, the first illustrative example of an explosion-proof CDR, not being part of the present invention,<NUM> may include a cap <NUM> formed with a cap flange <NUM> around a portion thereof. A central bore may be positioned in the cap <NUM> to accommodate a sleeve <NUM> and/or a shaft <NUM>. It is contemplated that in most applications the shaft <NUM> will be rotatable with respect to a piece of equipment, such as an electric motor (not shown). The cap <NUM> may be formed with a cap axial interior surface 271a and a cap axial exterior surface 271b, which may extend to the cap flange <NUM> as shown in <FIG>, and in most applications it is contemplated that the cap axial interior surface 271a may be positioned to abut a housing from which the shaft <NUM> protrudes. The interface between the cap axial interior surface 271a and the housing may be sealed and/or one or more sealing members (e.g., o-rings) may be positioned between the cap <NUM> and housing alone or in combination with a deformable substance to ensure definition of the proper flame path. Such deformable substances include but are not limited to epoxies, chemical adhesives, ceramics, metals, polymers, and/or combinations thereof.

The cap <NUM> may be formed with a cap body <NUM> extending axially from the cap flange <NUM>. A plurality of body radial bores 276a may be formed in the cap body <NUM> to accommodate a conductive assembly <NUM> and/or plug <NUM>. Each body radial bore 276a may extend from the exterior surface of the cap body <NUM> into the central bore of the cap <NUM> (see <FIG>). The example of an explosion-proof CDR <NUM> shown in <FIG> includes six body radial bores 276a and six corresponding conductive assemblies <NUM> and plugs <NUM>. However, the optimal number of body radial bores 276a, conductive assemblies <NUM>, and/or plugs <NUM> will vary from one application of the explosion-proof CDR <NUM> to the next, and is therefore in no way limiting to the scope thereof.

The conductive assembly <NUM> and/or plug <NUM> may be similar to the conductive assemblies <NUM>, <NUM> as previously disclosed herein and configured to make electrical contact with a shaft <NUM> and/or sleeve <NUM>. Alternatively, the conductive assembly <NUM> may comprise any structure and/or method that provides an adequate electrical pathway for current from the shaft <NUM> and/or sleeve <NUM> to the explosion-proof CDR <NUM>. The plug <NUM> may seal the conductive assembly <NUM> from the external environment, and may also assist in properly retaining a portion of the conductive assembly <NUM> within the cap <NUM>. In the illustrative example, the plug <NUM> may engage the cap <NUM> via conventional threads for relatively easy removal/installation, but any suitable structure and/or method may be used to adequately engage the plug <NUM> and/or conductive assembly <NUM> with the cap <NUM> without limitation. It is contemplated that a portion of the conductive assembly <NUM> will contact the shaft <NUM> and another portion thereof will simultaneously contact either the stator <NUM> and/or cap <NUM> for direct conduction of current from the shaft <NUM> through the explosion-proof CDR <NUM> to the equipment housing (not pictured). The cap body <NUM> may be formed with a cap axial projection <NUM> and cap groove <NUM> adjacent the distal end of the cap body <NUM> (see <FIG> & <FIG>). In this example of an explosion-proof CDR <NUM>, the radially inward portion of a body radial bore 276a may intersect the cap groove <NUM>. The distal axial face of the cap body <NUM> may be formed with one or more fastener receivers <NUM> for cooperative engagement with one or more fasteners <NUM> that may be used to engage a stator <NUM> to the cap <NUM> as described in further detail below.

The first illustrative example of an explosion-proof CDR <NUM> may also include a stator <NUM> cooperating with the cap <NUM>. The geometry and various interface surfaces leading from the area adjacent the cap groove <NUM> to an area external to the explosion-proof CDR <NUM> (sometimes referred to herein as the "flame path") may be specifically designed (e.g., width, length, transitions, etc. of interfaces between the stator <NUM> and cap <NUM>) to pass the standards previously disclosed herein or other standards without limitation. Typically, if a flame and/or ignition originates in the explosion-proof CDR <NUM>, the flame may move outward therefrom. Generally, the flame path may be designed to have enough distance and volume to an area external to the explosion-proof CDR <NUM> such that when the flame exits the explosion-proof CDR <NUM>, the flame has sufficiently cooled such that it cannot ignite material (e.g., gases, vapors, etc.) external to the explosion-proof CDR <NUM>. Generally, such a design requires relatively tight tolerances along the flame path.

The stator <NUM> may be formed with a central bore to accommodate a sleeve <NUM> and/or a shaft <NUM>. The stator <NUM> may also include an axial projection <NUM> that may be configured to encompass all or a portion of the cap body <NUM> (see <FIG>). A stator radial exterior surface <NUM> la may be positioned toward the external environment and a stator radial interior surface <NUM> lb may be positioned toward the shaft <NUM> and/or sleeve <NUM>. The stator <NUM> may also include a stator groove <NUM> configured to cooperate with the cap axial projection <NUM> (see <FIG> & <FIG>) such that the contact portion of the conductive assembly <NUM> may be positioned within the cap groove <NUM> and adjacent the stator groove <NUM>. As previously mentioned, the configuration of the various interface passages between the stator <NUM> and cap <NUM> may vary from one application to the next, and may be specifically designed for the specific certifications disclosed above and/or other certifications.

The stator <NUM> may be engaged with the cap <NUM> via a one or more fasteners <NUM> passing through corresponding apertures formed in the stator <NUM> and engaging one or more fastener receivers <NUM> formed in the cap body <NUM> as previously described. Generally, it is contemplated that for most applications of the explosion-proof CDR <NUM> it will be desirable for the stator <NUM> to be rigidly and securely engaged with the cap <NUM>. However, the scope of the explosion-proof CDR <NUM> is not so limited. Accordingly, and suitable structure and/or method for engaging the stator <NUM> with the cap <NUM> for the particular application of the explosion-proof CDR <NUM> may be used therewith without limitation.

In the first illustrative example of an explosion-proof CDR <NUM>, a sleeve <NUM> may be engaged with the shaft <NUM>. The sleeve <NUM> may be formed with one or more sleeve grooves 204a on the surface thereof that is adjacent the shaft <NUM> during use. An o-ring <NUM> may be positioned in a sleeve groove 204a to engage the sleeve <NUM> with the shaft <NUM> in such a manner that the sleeve <NUM> rotates with the shaft <NUM>. The o-rings <NUM> may be formed of a low or relatively low impedance material including but not limited to silicon with embedded and/or entwined silver and/or aluminum components, metallic braids, other conductive compounds, and/or combinations thereof. One such o-ring <NUM> that may be suitable for certain applications is offered for sale by Kemtron Co. , in Braintree, Essex, UK, and is comprised of a fully cured silicone and/or flourosilicone loaded with a variety of highly conductive particles, which particles may include but are not limited to silver, aluminum, other metallic compounds, other conductive compounds, and/or other combinations thereof. This o-ring <NUM> may be specifically configured to ensure galvanic compatibility while simultaneously providing low contact resistance between mating surfaces. Furthermore, if it may be desirable for any drive rings and/or o-rings disclosed for any examples of a bearing isolator and/or CDR disclosed herein, such drive rings and/or o-rings may be so configured without limitation.

In another illustrative example, the sleeve <NUM> may be engaged with the shaft <NUM> via chemical adhesives and/or the sleeve <NUM> may be configured as a conductive tape or other self-adhering member. In still other examples the sleeve <NUM> may be press-fit onto the shaft <NUM> (i.e., interference fit), or engaged therewith via other mechanical fasteners (e.g., set screws, bolts, etc.), welds, and/or any combination of the foregoing. Accordingly, the scope of the explosion-proof CDR <NUM> is in no way limited by the presence or absence of a sleeve <NUM>, and if a sleeve <NUM> is used, the specific structure and/or method used to properly engage the sleeve <NUM> with the shaft <NUM> in no way limits the scope of the explosion-proof CDR <NUM>. The length of the sleeve <NUM> in the first illustrative example of the explosion-proof CDR <NUM> is approximately equal to the axial dimension of the explosion-proof CDR <NUM> when the stator <NUM> and cap <NUM> are engaged with one another, wherein the sleeve <NUM> is slightly offset toward the exterior of the explosion-proof CDR <NUM> in the axial dimension (see <FIG>).

Using a sleeve <NUM> may provide several advantages. First, it may allow the manufacturer and/or user to precisely control the tolerances at the point where electrical contact is made between the conductive assemblies <NUM> and the rotational element (e.g., sleeve <NUM>, shaft <NUM>) when designing a flame path in the explosion-proof CDR <NUM>. Second, such use of a sleeve <NUM> may also allow the designer to overcome problems in defining a flame path with an imprecisely machined shaft <NUM>. Oftentimes the exterior surface of a shaft <NUM> may be irregular, nonuniform, or constructed of a material prone to corrosion, pitting, and/or other degradation. It is contemplated that a sleeve <NUM> may be especially useful in applications in which a smoother, more uniform surface is required for contact between a rotating member and shaft grounding device, including but not limited to any of the bearing isolators <NUM> and/or CDRs <NUM>, <NUM>, 80a, <NUM>, <NUM>, <NUM>', captured CDR <NUM>, and/or explosion-proof CDRs <NUM> disclosed herein. The sleeve <NUM> may be formed with a smooth, uniform exterior surface to provide an optimal surface for a conductive insert <NUM> or other conductive member to contact. It is contemplated that using a sleeve <NUM> in conjunction with a shaft grounding device will increase the performance and longevity of the shaft grounding device.

As mentioned, the sleeve <NUM> may include one or more sleeve grooves 204a formed on the interior surface thereof, which interior surface will be adjacent the exterior surface of a shaft <NUM> during use. The illustrative example includes three sleeve grooves <NUM>, wherein the axial limits of each sleeve groove 204a may be defined by an end wall on a first side and an interior wall on a second side. Other examples of a shaft sleeve <NUM> may include more or fewer sleeve grooves 204a without limitation. Also, in the illustrative example the height of each end wall and the interior wall may be equal, but this configuration in no way limits the scope of the sleeve <NUM>.

Again, an o-ring <NUM> acting as a drive ring may be positioned within each sleeve groove <NUM>. It is contemplated that the o-ring(s) <NUM> may be configured engage the sleeve <NUM> with the shaft <NUM> such that the sleeve <NUM> rotates with the shaft <NUM>. It is further contemplated that the o-ring(s) <NUM> may be constructed of a low-impedance material, such that current from the shaft <NUM> may be easily transmitted from the o-ring <NUM> to the sleeve <NUM>, from where they may pass through a shaft grounding device. It is contemplated that one o-ring <NUM> may be positioned in each sleeve groove 204a, but the sleeve <NUM> as disclosed herein is not so limited. The o-ring <NUM> may be formed of any material that is suitable for the particular application for which the sleeve <NUM> will be used. For example, it is contemplated that in some examples, the o-ring(s) <NUM> may be formed of a synthetic, low-impedance rubber or rubber-like material. However, in other examples the o-ring(s) <NUM> may be formed of metallic coated fibers. Accordingly, the specific material used to construct the o-ring(s) <NUM> in no way limits the scope of the sleeve <NUM>.

Another illustrative example of an explosion-proof CDR <NUM> is shown in <FIG> & <FIG>. This illustrative example of an explosion-proof CDR <NUM> includes a stator <NUM> and a rotor <NUM>. As with some examples of the captured CDR <NUM> disclosed herein, the stator <NUM> may be mounted to a housing for a piece of equipment (neither pictured) with a shaft <NUM> protruding therefrom. The rotor <NUM> may be mounted to the shaft <NUM> so as to rotate therewith. As best shown in <FIG>, this example of an explosion-proof CDR <NUM> may be formed with one or more radial bores <NUM> in the stator <NUM>. The radial bores <NUM> may be configured to accommodate a conductive assembly <NUM> so that a portion thereof contacts the shaft <NUM> as previously described for other examples of the explosion-proof CDR <NUM> without limitation.

Referring now to <FIG>, which provides an axial-cross sectional view of this example of the explosion-proof CDR <NUM>, a cap <NUM> may be configured to engage a portion of the stator <NUM>, thereby enclosing a portion of the rotor <NUM> within the stator <NUM> and cap <NUM>. The cap <NUM> may be engaged with the stator <NUM> in a secure manner using fasteners <NUM> as best shown in <FIG>. Alternatively, the cap <NUM> may be engaged with the stator <NUM> in the desired manner using any method and/or structure suitable for the particular application of the explosion-proof CDR <NUM>, including but not limited to chemical adhesives, interference fittings, welding, and/or combinations thereof. The cap <NUM> may be formed with a plurality of cap fastener channels <NUM> corresponding to the fastener channels <NUM> formed in the stator <NUM>, depending on the specific example of the explosion-proof CDR <NUM>.

The rotor <NUM> may be mounted to the shaft <NUM> so that it rotates therewith. In the pictured examples of an explosion-proof CDR <NUM> utilizing a rotor <NUM>, a plurality of o-rings <NUM> are used to mount the rotor <NUM> to the shaft <NUM>. However, any other method and/or structure suitable for the particular application of the explosion-proof CDR <NUM> may be used without limitation, including but not limited to adhesives, interference fittings, welding, set screws, and/or combinations thereof.

In this example of the explosion-proof CDR <NUM>, not being part of the present invention, the stator <NUM> may include a stator radial exterior surface 251a with which the distal end of the radial bores <NUM> may intersect. The stator <NUM> may also include a stator radial interior surface <NUM> lb oriented toward the rotor <NUM> (if present for that example of an explosion-proof CDR <NUM>). The example of a stator <NUM> shown in <FIG> may be formed with one or more stator grooves <NUM> that may correspond to one or more rotor axial projections <NUM> and/or rotor radial projections <NUM>. The stator <NUM> may also include one or more axial projections <NUM> and/or radial projections <NUM> that may correspond to one or more rotor grooves <NUM> and/or cap grooves <NUM>. One stator radial projection <NUM> on the equipment side of the explosion-proof CDR <NUM> (generally oriented toward the left in the orientation shown in <FIG>) may extend toward the shaft <NUM> to create a relatively tight clearance between that stator radial projection <NUM> and the shaft <NUM>. The various interface passages between the stator <NUM> and rotor <NUM>, stator <NUM> and cap <NUM>, and/or rotor and cap <NUM> may be configured such that the explosion-proof CDR <NUM> meets certain certification criteria.

Still referring to <FIG>, this example of an explosion-proof CDR <NUM> may include a rotor <NUM> formed with a rotor radial exterior surface 261a oriented toward a portion of the stator <NUM> and a rotor radial interior surface 261b oriented toward a shaft <NUM>. One or more o-ring channels <NUM> may be fashioned in the rotor radial interior surface 261b to receive an o-ring <NUM> to mount the rotor <NUM> to the shaft <NUM> in a desired manner. As explained above, other methods and/or structures may be used to mount the rotor <NUM> to the shaft <NUM> without limitation. It is contemplated that if o-rings <NUM> are used, it will be most advantageous for those o-rings <NUM> to be constructed of a material that is sufficiently conductive. The rotor <NUM> in the example of an explosion-proof CDR <NUM> shown in <FIG> may include a rotor radial projection <NUM> having one or more rotor axial projections <NUM> extending therefrom, which projections <NUM>, <NUM> may cooperate with one or more stator grooves <NUM> and/or cap grooves <NUM> to form a flame path for the appropriate certification are previously mentioned. The most distal rotor radial exterior surface 261a may cooperate with a stator radial interior surface 251b to define an interface channel <NUM> between the stator <NUM> and the rotor <NUM> in which a portion of the conductive assembly <NUM> may be positioned. It is contemplated that a portion of the conductive assembly <NUM> will contact the shaft <NUM> and another portion thereof will contact the stator <NUM> simultaneously for direct conduction of current from the shaft <NUM> through the explosion-proof CDR <NUM> to the equipment housing (not pictured).

This example of an explosion-proof CDR <NUM> may include a cap <NUM> formed with a cap axial interior surface 271a, a portion of which may abut the stator <NUM>, and a cap axial exterior surface 271b, a portion of which may be exposed to the external environment. One or more cap grooves <NUM> may be formed in a portion of the cap axial interior surface 271a. Additionally, the cap <NUM> may be formed with one or more cap axial projections <NUM> and/or cap radial projections <NUM> to cooperate with rotor grooves <NUM> and/or rotor axial and/or radial projections <NUM>, <NUM> to form the desired flame path. One cap radial projection <NUM> on the external side of the explosion-proof CDR <NUM> (generally oriented toward the right in the orientation shown in <FIG>) may extend toward the shaft <NUM> to create a relatively tight clearance between that cap radial projection <NUM> and the shaft <NUM>.

Another illustrative example of an explosion-proof CDR <NUM> is shown in <FIG>& <FIG>. The example utilizes a stator <NUM> but not a rotor <NUM>. The stator <NUM> in this example of an explosion-proof CDR <NUM> is configured substantially similar to the radial CDR <NUM> disclosed above. The stator <NUM> may be formed with one or more radial bores <NUM> to accommodate a conductive insert <NUM> and plug <NUM> (if desired) in a manner substantially the same as previously described for other examples of an explosion-proof CDR <NUM>. Additionally, the stator <NUM> in this example of an explosion-proof CDR <NUM> may be engaged directly with a housing. The stator <NUM> may be formed with one or more fastener channels <NUM> into which respective fasteners <NUM> may be inserted to mount the stator <NUM> to a housing. As described for the bearing isolators <NUM> and other CDRs <NUM>, <NUM>, 80a, <NUM>, <NUM>, <NUM>, and/or captured CDR <NUM>, any suitable mounting structure(s) and/or method(s) may be used to mount the stator <NUM> to a housing. Accordingly, the specific structure and/or method for properly mounting a stator <NUM> in no way limits the scope of any explosion-proof CDR <NUM> as disclosed and claimed herein.

Still referring to <FIG>& <FIG>, this example of an explosion-proof CDR <NUM> may also include a cap <NUM> having a cap axial interior surface 271a, a portion of which may be positioned adjacent a housing during use. The cap <NUM> may also include a cap axial exterior surface 271b opposite the housing. The cap <NUM> may include a cap flange <NUM> to provide additional surface area for the portion of the cap axial interior surface 271a that is positioned adjacent the housing. The cap <NUM> may also include a cap groove <NUM> configured to accommodate the stator <NUM>. The cap <NUM> may be formed with one or more cap fastener channels <NUM> into which respective fasteners <NUM> may be inserted to mount the cap <NUM> to a housing. As described for the bearing isolators <NUM> and other CDRs <NUM>, <NUM>, 80a, <NUM>, <NUM>, <NUM>, and/or captured CDR <NUM>, any suitable mounting structure(s) and/or method(s) may be used to mount the cap <NUM> to a housing. Accordingly, the specific structure and/or method for properly mounting a cap <NUM> in no way limits the scope of any explosion-proof CDR <NUM> as disclosed and claimed herein. To adequately define a flame path, a deformable substance (not shown) having the required electrical and mechanical properties may be positioned between the housing and the portion of the cap axial interior surface 271a adjacent the housing as previously described. Another illustrative example of an explosion-proof CDR <NUM> is shown in <FIG>& <FIG>. This example is similar to that shown in <FIG>& <FIG> in that no rotor <NUM> is used. However, in this example, the stator <NUM> may be mounted to a portion of the axial interior surface 271a of the cap <NUM> rather than mounting the stator <NUM> to the housing. Accordingly, it is contemplated that the cap <NUM> in this example of an explosion-proof CDR <NUM> will be mounted directly to the housing.

Another illustrative example of an explosion-proof CDR <NUM> is shown in <FIG> & <FIG>. This example is similar to that shown in <FIG> & <FIG> in that it employs a stator <NUM> and a rotor <NUM>. However, in this example of an explosion-proof CDR <NUM>, the stator grooves <NUM>, axial and radial projections <NUM>, <NUM> of the stator <NUM>, rotor grooves <NUM>, rotor axial and radial projections <NUM>, <NUM>, cap grooves <NUM>, and cap axial and radial projections <NUM>, <NUM> cooperate to form a different flame path than that shown in <FIG> & <FIG> in the respective examples shown in those figures. Accordingly, the rotor <NUM> in those examples may be formed with a rotor radial projection <NUM> extending into a stator groove <NUM>, wherein one axial face of the rotor radial projection <NUM> is adjacent a radial projection <NUM> of the stator <NUM> and the opposite axial face thereof is adjacent a cap axial projection <NUM>.

Another illustrative example of an explosion-proof CDR <NUM>, not being part of the present invention, is shown in <FIG>& <FIG>. This example is similar to those shown in <FIG> in that it employs a stator <NUM> and a rotor <NUM>. However, in this example of an explosion-proof CDR <NUM>, the stator grooves <NUM>, axial and radial projections <NUM>. <NUM> of the stator <NUM>, rotor grooves <NUM>, rotor axial and <NUM> radial projections <NUM>, <NUM>, cap grooves <NUM>, and cap axial and radial projections <NUM>, <NUM> cooperate to form a different flame path than that shown in <FIG> & <FIG> in the respective examples shown in those figures. Accordingly, the rotor <NUM> in this examples may be formed with a rotor radial projection <NUM> extending into a stator groove <NUM>, wherein one axial face of the rotor radial projection <NUM> is adjacent a radial projection <NUM> of the stator <NUM><NUM> and the opposite axial face thereof is adjacent a cap axial projection <NUM>.

Any of the various features for the bearing isolator <NUM>, CDR <NUM>, <NUM>, 80a, <NUM>, <NUM>, <NUM>, captured CDR <NUM>, intelligent CDR <NUM>', and/or explosion-proof CDR <NUM> disclosed in the present application may be used alone or in combination with one another depending on the compatibility of the features. Accordingly, an infinite number of variations of the bearing isolator <NUM>, CDR <NUM>, <NUM>, 80a, <NUM>, <NUM>, <NUM>, captured CDR <NUM>, intelligent CDR <NUM>', and/or explosion-proof CDR <NUM> exists. Modifications and/or substitutions of one feature for another in no way limit the scope of the bearing isolator <NUM>, CDR <NUM>, <NUM>, 80a, <NUM>, <NUM>, <NUM>, captured CDR <NUM>, intelligent CDR <NUM>', and/or explosion-proof CDR <NUM>.

The bearing isolator <NUM>, CDR <NUM>, <NUM>, 80a, <NUM>, <NUM>, <NUM>, captured CDR <NUM>, intelligent CDR <NUM>', and/or explosion-proof CDR <NUM> employed with an equipment housing <NUM> may be configured to create a stable, concentric system with the rotating shaft <NUM> as the center point. Inserting a CDR <NUM>, <NUM>, 80a, <NUM>, <NUM>, <NUM>, captured CDR <NUM>, intelligent CDR <NUM>', and/or explosion-proof CDR <NUM> into bearing isolator <NUM> such as the one shown in <FIG> and <FIG> within the equipment housing <NUM> may form a relatively fixed and stable spatial relationship between the conducting elements, which may improve the collection and conduction of electrostatic discharge from the shaft <NUM>, <NUM> to ground, through the conducting elements of the CDR <NUM>, <NUM>, 80a, <NUM>, <NUM>, <NUM>, captured CDR <NUM>, intelligent CDR <NUM>', and/or explosion-proof CDR <NUM> and bearing isolator <NUM>. This improved motor ground sealing system may directly seat major elements together, which may compensate for imperfections in the shaft <NUM>, <NUM> (which may not be perfectly round) and may ensure that the variation or change in distance from the conductive segments <NUM> to the surface of the shaft <NUM> caused by external forces acting on the bearing isolator <NUM>, and/or CDR <NUM>, <NUM>, 80a, <NUM>, <NUM>, <NUM>, captured CDR <NUM>, intelligent CDR <NUM>', and/or explosion proof CDR <NUM> is minimal. This may promote effective conduction of electrical charges from the shaft <NUM>, <NUM> to the equipment housing <NUM>.

For various embodiments and/or applications of the bearing isolator <NUM>, CDR <NUM>, <NUM>, 80a, <NUM>, <NUM>, <NUM>, captured CDR <NUM>, intelligent CDR <NUM>', and/or explosion-proof CDR <NUM>, it may be necessary to engage one component with another component in a secure manner such that the two components are fixedly positioned with respect to one another. In such embodiments and/or applications the two components may be engaged with one another via any suitable method and/or structure, including but not limited to one or more o-rings and/or drive rings, mechanical fasteners (e.g., set screws, bolts, pins, etc.), adhesives (tapes, glues, epoxies, etc.), welds, press fit (i.e., interference fit), and/or any combinations thereof.

Claim 1:
A current diverter ring (CDR) (<NUM>; <NUM>; <NUM>; <NUM>; <NUM>) comprising:
a. a body (<NUM>; <NUM>) that is substantially ring-shaped;
b. a main aperture (<NUM>) positioned in the center of said main body (<NUM>; <NUM>) and through which a shaft (<NUM>) may be positioned in a rotatable manner with respect to said CDR (<NUM>; <NUM>; <NUM>; <NUM>; <NUM>);
c. a first radial channel (<NUM>; <NUM>; <NUM>; <NUM>; <NUM>), wherein said first radial channel (<NUM>; <NUM>; <NUM>; <NUM>; <NUM>) extends from the radial exterior surface (85a; 165a; 215a) of said body (<NUM>; <NUM>) to the radial interior surface (85b; 165b; 215b) of said body (<NUM>; <NUM>);
d. a first conductive assembly (<NUM>) positioned in said first radial channel (<NUM>; <NUM>; <NUM>; <NUM>; <NUM>), wherein a contact portion (86b) of said first conductive assembly (<NUM>) protrudes from said first radial channel (<NUM>; <NUM>; <NUM>; <NUM>; <NUM>) radially inward past said radial interior surface (85b; 165b; 215b);
e. a second radial channel (<NUM>; <NUM>; <NUM>; <NUM>; <NUM>), wherein said second radial channel (<NUM>; <NUM>; <NUM>; <NUM>; <NUM>) extends from the radial exterior surface (85a; 165a; 215a) of said body (<NUM>; <NUM>) to the radial interior surface (85b; 165b; 215b) of said body (<NUM>; <NUM>);
characterized in that the current diverter ring further comprises
f. an indicator conductive assembly (<NUM>') positioned in said second radial channel (<NUM>; <NUM>; <NUM>; <NUM>; <NUM>), wherein a contact portion (214b') of said indicator conductive assembly (<NUM>') protrudes from said second radial channel (<NUM>; <NUM>; <NUM>; <NUM>; <NUM>) radially inward past said radial interior surface (85b; 165b; 215b);
g. an indicator (<NUM>') in electrical communication with a power source (<NUM>') and with said indicator conductive assembly (<NUM>'), wherein said indicator (<NUM>') is configured to alert a user of a presence or absence of electrical contact in a circuit comprised of said first conductive assembly (<NUM>), said indicator conductive assembly (<NUM>'), and said shaft (<NUM>).