WO2020180939A1

WO2020180939A1 - Conductive rubber block for a rail wheel and associated methods

Info

Publication number: WO2020180939A1
Application number: PCT/US2020/020908
Authority: WO
Inventors: Thomas Christen
Original assignee: Lord Corporation
Priority date: 2019-03-05
Filing date: 2020-03-04
Publication date: 2020-09-10

Abstract

Electrical grounding devices, systems, and methods of manufacture and use thereof are advantageously implemented in providing electrical grounding between electrically conductive elements between when it is desired to maintain a continuous and uninterrupted gap during normal operation. One example embodiment for the implementation of such electrical grounding devices, systems, and methods of manufacture and use is in a railcar wheel assembly. Such systems can include inner and outer wheel portions arranged concentrically about each other, with rubber blocks having one or more grounding shunts passing through a thickness thereof being arranged between the inner and outer wheel portions in a compression-fit manner, the grounding shunts being in electrical contact with each of both of the inner and outer wheel portions to conduct an electrical current therebetween.

Description

CONDUCTIVE RUBBER BLOCK FOR A RAIL WHEEL AND ASSOCIATED METHODS

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to U.S. Provisional Patent Application Serial No. 62/814,044, filed March 5, 2019, the disclosure of which is incorporated herein by reference in its entirety.

TECHNICAL FIELD

[0001] The subject matter disclosed herein relates to systems and methods for electrical current discharge. In particular, the presently disclosed subject matter relates to systems for electrical current discharge across an insulating element installed in a railcar wheel, as well as associated methods of use and manufacture thereof.

BACKGROUND

[0002] Rail transport has been used throughout modern history as a way of moving people and cargo over large distances. At first, solid wheels were used to move railcars along the rails. However, owing to the metal-to-metal contact between the wheels and the rails, significant vibration was transmitted into the railcars by these solid wheels. It is now known, as shown in the example illustrations of FIGS. 1-3, for wheels, generally designated 10, used in rail transportation to have a multi-part design, having at least concentric inner and outer wheel portions 20, 30 that are separated from, and connected to, each other by one or more rubber blocks 40 that are retained within a channel defined between the outer circumferential edges of the inner and outer wheel portions. These rubber blocks 40 act, typically in conjunction with a suspension installed on the railcar itself, to dissipate or otherwise damp vibratory or other force inputs into the outer wheel portion 30 from the rail with which the wheel 10 is in contact. The compliance of the rubber blocks 40 enables relative radial deflections of the inner wheel portion 20 relative to the outer wheel portion 30 when a force input is received from the rail by the outer wheel portion 30. Furthermore, the compliant aspects allow for reduced motion transfer between the inner and outer wheel portions 20, 30. As shown in the example arrangement shown in FIGS. 1-3, the rubber blocks 40 are shown being retained within respective“C” channels formed between the inner and outer wheel portions 20, 30. Each rubber block 40 is pre compressed when installed between the inner and outer wheel portions 20, 30 and a small gap 50 (e.g., a continuous and uninterrupted seam) is present between the inner and outer wheel portions 20, 30, such that the inner wheel portion 20 does not contact the outer wheel portion 30 (e.g., by translator movement in the radial direction) during normal operation of the wheel 10.

[0003] During normal operation, it is necessary to dissipate static electricity that accumulates in/on the wheel 10 through a grounding path. For this electrical grounding to be effective, potentially large amounts of electrical current must be transferred from the railcar into the rail, via the rail wheels 10, in order to ensure safe operation of the railcar. In solid wheel systems, the conductive metal wheel acts as a conduction path to ground the railcar, but in modem-day compliant railcar wheel systems, such as in wheel 10 in FIGS. 1-3, where the inner and outer wheel portions 20, 30 are separated by an insulative damper, for example, the plurality of rubber blocks 40, no direct conduction path exists between the inner and outer wheel portions 20, 30, which would otherwise allow for the electric current to be transmitted from the inner wheel portion 20, into the outer wheel portion 30, and ultimately into the rail with which the outer wheel portion 30 is in direct (e.g., rolling) contact. As such, it has been necessary to electrically connect the inner wheel portion 20 to the outer wheel portion 30. Presently known designs require a grounding shunt 60 to be electrically connected, at a first end thereof, to the inner wheel portion 20 and, at a second end thereof, to the outer wheel portion 30, thereby establishing an electrical conduction path between the inner and outer wheel portions 20, 30. These grounding shunts 60 are typically made of braided copper wire 62, with stainless steel end flanges 64 attached at the ends of the wire 62 by a wire-flange coupler 66 to allow for mechanical and electrical connection to the respective outer faces of the inner and outer wheel portions 20, 30.

[0004] However, these grounding shunts 60 are prone to failure, for example, by breaking off at one or more of the surfaces of the inner and/or outer wheel portions 20, 30 to which the grounding shunts 60 are connected, leading to increases in maintenance costs for railcar operators due to the need to routinely inspect and replace broken grounding shunts 60 in order to allow for safe operation of the railcar to which the wheel 10 is attached. In most instances, the end flanges 64 are screwed, welded, soldered, etc. onto the outer face of the inner and outer wheel portions 20, 30. In some instances, the attachment points formed on the inner and outer wheel portions 20, 30 act as stress concentration points, such that the structural integrity of the respective inner and/or outer wheel portions 20, 30 themselves can become compromised, e.g., by vibration of, and relative movement between, the inner and outer wheel portions 20, 30 that can cause metal fatigue. It is known that such metal fatigue can introduce micro cracks and the like during normal operation of the railcar wheel 10. In some other instances, where the mechanical attachment of the end flange 64 to the respective inner or outer wheel portion 20, 30 fails due to a foreign object striking it, whichever of the inner and/or outer wheel portion 20, 30 to which the end flange 64 of the grounding shunt 60 was attached may also experience significant damage due to the rupturing of the mechanical attachment between the grounding shunt 60 and the inner and/or outer wheel portions 20, 30. Regardless of the particular failure mechanism, it is known from the prior art that the outer faces of the inner and outer wheel portions 20, 30 on which the end flanges 64 of the grounding shunts 60 are mechanically attached can suffer significant damage upon a failure of the mechanical retention of the end flange 64 to the respective one of the inner and/or outer wheel portions 20, 30, which requires removal and replacement or disassembly and refurbishment of the entire wheel 10 of the railcar. Considering the size and costs associated with installation, removal, and servicing of a wheel 10 of a railcar, as well as the costs of the wheel itself, the failure of even a single grounding shunt 60 as disclosed in the prior art can result in a significant financial impact, both in terms of the labor and costs associated with removal and repair/replacement of such a wheel 10, but also from the associated downtime of the railcar to which the wheel 10 is attached while the maintenance service is performed.

[0005] As such, a need exists for a system for electrical current discharge across an insulating element installed in a wheel of a railcar and associated methods of use and manufacture. SUMMARY

[0006] An electrical grounding device for a railcar wheel assembly is provided. The electrical grounding device comprises: a rubber block comprising a through-hole formed through an entirety of a thickness of the rubber block, wherein the rubber block is configured to be compressively arranged between an inner wheel portion and an outer wheel portion of a railcar wheel assembly and provide vibrational isolation between the inner and outer wheel portions; and a grounding shunt comprising: a cable disposed through the through-hole; a first flange attached to a first end of the cable; and a second flange attached to a second end of the cable; wherein the first flange is configured to electrically contact the inner wheel portion and the second flange is configured to electrically contact the outer wheel portion; and wherein the cable is configured to conduct an electrical current between the inner wheel portion and the outer wheel portion through the rubber block.

[0007] In some embodiments of the device, the cable is a flexible cable comprising braided strands of electrically conductive wire.

[0008] In some embodiments of the device, the through-hole has a diameter that is larger than a diameter of the cable.

[0009] In some embodiments of the device, the grounding shunt has a length that is substantially similar to an uncompressed thickness of the rubber block.

[0010] In some embodiments of the device, the cable is configured to flex, bend, and/or deflect within the through-hole when the rubber block is compressed by relative movement between the inner and outer wheel portions, so that effectively no stiffness is added to the rubber block by the grounding shunt.

[0011] In some embodiments of the device, the first and/or second flanges comprise one or more keyed portions, at least one flange insertion slot is provided in the rubber block, the at least one flange insertion slot being radially connected to the through-hole, and the at least one flange insertion slot is configured such that the first and/or second flanges can be inserted through the rubber block so that the cable is installed in the through-hole only when the first and/or second flanges are oriented such that the one or more keyed portions can pass through the at least one flange insertion slot.

[0012] In some embodiments of the device, the first and second flanges each comprise a collar, each collar being rigidly connected to the cable at one of the first and second ends thereof.

[0013] In some embodiments of the device, the mbber block comprises, on both a radially inner surface and on a radially outer surface of the rubber block, a flange recess configured such that one of the first and second flanges rest within the flange recess on whichever of the radially inner or outer surfaces that the first or second flange is arranged when the grounding shunt is installed within the rubber block.

[0014] In some embodiments of the device, the flange recesses have a depth in a direction of the thickness of the rubber block such that, when the grounding shunt is installed within the rubber block, a surface of the first flange by which the first flange contacts the inner wheel portion is substantially coplanar to the radially inner surface of the rubber block and a surface of the second flange by which the second flange contacts the outer wheel portion is substantially coplanar to the radially outer surface of the rubber block.

[0015] An electrical grounding system for a railcar wheel assembly is provided. The electrical grounding system comprises: an inner wheel portion; an outer wheel portion arranged concentrically around the inner wheel portion to define a channel between the inner and outer wheel portions ; a plurality of rubber blocks, each of which comprises a through-hole formed through an entirety of a thickness of the rubber block, wherein the rubber blocks are arranged radially about the railcar wheel assembly within the channel by compression to provide vibrational isolation between the inner and outer wheel portions and to space the inner wheel portion apart from the outer wheel portion, thereby defining an annular gap between the inner and outer wheel portions when the inner and outer wheel portions are in an undeflected position; and a plurality of grounding shunts, each of the grounding shunts being arranged to pass through a corresponding through-hole of one of the plurality of rubber block, each of the grounding shunts comprising: a cable disposed through the through-hole; a first flange attached to a first end of the cable; and a second flange attached to a second end of the cable; wherein each of the first flanges is configured to electrically contact the inner wheel portion and each of the second flanges is configured to electrically contact the outer wheel portion; and wherein each cable is configured to conduct an electrical current between the inner wheel portion and the outer wheel portion through the rubber block in which the cable is disposed.

[0016] In some embodiments of the system, each cable is a flexible cable comprising braided strands of electrically conductive wire.

[0017] In some embodiments of the system, each through-hole has a diameter that is larger than a diameter of the cable arranged therein.

[0018] In some embodiments of the system, each grounding shunt has a length that is substantially similar to an uncompressed thickness of the rubber block through which the grounding shunt is installed.

[0019] In some embodiments of the system, each cable is configured to flex, bend, and/or deflect within the through-hole when the rubber block is compressed by relative movement between the inner and outer wheel portions, so that effectively no stiffness is added to the rubber block by the grounding shunt.

[0020] In some embodiments of the system, the first and/or second flanges comprise one or more keyed portions, at least one flange insertion slot is provided in each rubber block, the at least one flange insertion slot being radially connected to the through-hole, and the at least one flange insertion slot is configured such that the first and/or second flanges can be inserted through the rubber block so that the cable is installed in the through-hole only when the first and/or second flanges are oriented such that the one or more keyed portions can pass through the at least one flange insertion slot.

[0021] In some embodiments of the system, the first and second flanges each comprise a collar, each collar being rigidly connected to the cable at one of the first and second ends thereof.

[0022] In some embodiments of the system, each rubber block comprises, on both a radially inner surface and on a radially outer surface of the rubber block, a flange recess configured such that one of the first and second flanges rest within the flange recess on whichever of the radially inner or outer surfaces that the first or second flange is arranged when the grounding shunt is installed within a respective one of the plurality of rubber blocks.

[0023] In some embodiments of the system, the flange recesses have a depth in a direction of the thickness of the rubber block such that, when the grounding shunt is installed within the rubber block, a surface of each first flange by which each such first flange contacts the inner wheel portion is substantially coplanar to the radially inner surface of a respective one of the rubber blocks and a surface of each second flange by which each such second flange contacts the outer wheel portion is substantially coplanar to the radially outer surface of a respective one of the rubber blocks.

[0024] A method of manufacturing an electrical grounding device for a railcar wheel assembly is provided. The method comprises: providing a rubber block that can be compressively arranged between an inner wheel portion and an outer wheel portion of a railcar wheel assembly and provide vibrational isolation between the inner and outer wheel portions; forming a through-hole and at least one flange insertion slot radially connected to the through-hole through an entirety of a thickness of the rubber block; forming a grounding shunt by attaching a first electrically conductive flange to a first end of an electrically conductive cable and by attaching a second electrically conductive flange to a second end of the cable, wherein the first end is an opposite end of the cable from the second end; inserting the first flange into the rubber block via the at least one flange insertion slot and the through-hole; and passing the first flange through the thickness of the rubber block, so that the cable is located substantially entirely within the through-hole and the second flange is on an opposite side of the rubber block from the first flange, wherein the first and second flanges are arranged proximate to a respective outer surface of the rubber block when the grounding shunt is installed within the rubber block.

[0025] In some embodiments of the method, the cable is a flexible cable comprising braided strands of electrically conductive wire. [0026] In some embodiments of the method, the through-hole has a diameter that is larger than a diameter of the cable.

[0027] In some embodiments of the method, the grounding shunt has a length that is substantially similar to an uncompressed thickness of the rubber block.

[0028] In some embodiments of the method, the cable is configured to flex, bend, and/or deflect within the through-hole when the rubber block is compressed by relative movement between the inner and outer wheel portions, so that effectively no stiffness is added to the rubber block by the grounding shunt.

[0029] In some embodiments of the method, the rubber block is compressed and inserted within a channel formed between the inner and outer wheel portions of the railcar wheel assembly.

[0030] In some embodiments of the method, the first and/or second flanges comprise one or more keyed portions, and the at least one flange insertion slot has a cross-sectional shape that is compatible with the one or more keyed portions, such that the cable can only be installed in the through-hole when the first and/or second flanges are oriented such that the one or more keyed portions can pass through the at least one flange insertion slot.

[0031] In some embodiments of the method, the first and second flanges each comprise a collar, each collar being rigidly connected to the cable and the first and second ends thereof.

[0032] In some embodiments, the method comprises: forming flange recesses in the rubber block at opposing ends of the through-hole, on respective radially inner and outer surfaces of the rubber block; and arranging the first and second flanges within one of the flange recesses when the grounding shunt is installed within the rubber block.

[0033] In some embodiments of the method, the flange recesses have a depth in a direction of the thickness of the rubber block, such that, when the grounding shunt is installed within the rubber block, a surface of the first flange by which the first flange contacts the inner wheel portion is substantially coplanar to the radially inner surface of the rubber block and a surface of the second flange by which the second flange contacts the outer wheel portion is substantially coplanar to the radially outer surface of the rubber block.

[0034] A method of electrically grounding a railcar wheel assembly is provided. The method comprises: arranging an outer wheel portion concentrically around an inner wheel portion to define a channel between the inner and outer wheel portions of the railcar wheel assembly; inserting a plurality of rubber blocks within the channel radially about the railcar wheel assembly, wherein one or more of the plurality of rubber blocks are electrical grounding devices comprising a rubber block comprising a through-hole formed through an entirety of a thickness of the rubber block, wherein the rubber block is configured to be compressively arranged between an inner wheel portion and an outer wheel portion of a railcar wheel assembly and provide vibrational isolation between the inner and outer wheel portions; and a grounding shunt comprising: a cable disposed through the through-hole; a first flange attached to a first end of the cable; and a second flange attached to a second end of the cable; wherein the first flange is configured to electrically contact the inner wheel portion and the second flange is configured to electrically contact the outer wheel portion; and wherein the cable is configured to conduct an electrical current between the inner wheel portion and the outer wheel portion through the mbber block, and wherein a radial distance between surfaces by which the rubber blocks contact the inner and outer wheel portions is smaller than a thickness of the rubber blocks, so that the plurality of rubber blocks are compressed within the channel; and conducting an electrical current between the inner wheel portion and the outer wheel portion via the grounding shunts to dissipate and electrical charge generated by a railcar to which the railcar wheel assembly is rotatably attached.

[0035] In some embodiments of the method, each cable is a flexible cable comprising braided strands of electrically conductive wire.

[0036] In some embodiments of the method, each through-hole has a diameter that is larger than a diameter of the cable arranged therein. [0037] In some embodiments of the method, each grounding shunt has a length that is substantially similar to an uncompressed thickness of the rubber block through which the grounding shunt is installed.

[0038] In some embodiments of the method, each cable is configured to flex, bend, and/or deflect within the through-hole when the mbber block is compressed by relative movement between the inner and outer wheel portions, so that effectively no stiffness is added to the rubber block by the grounding shunt.

[0039] In some embodiments, the method comprises: forming one or more keyed portions on the first and or second flanges; forming at least one flange insertion slot in each rubber block, the at least one flange insertion slot being radially connected to the through-hole, and inserting the first flange and/or the second flange through one of the rubber blocks, so that the cable is installed in the through-hole, wherein the cable can only be installed in the through-hole when the first and/or second flanges are oriented such that the one or more keyed portions can pass through the at least one flange insertion slot.

[0040] In some embodiments of the method, the first and second flanges each comprise a collar, each collar being rigidly connected to the cable at one of the first and second ends thereof.

[0041] In some embodiments of the method, each rubber block comprises, on both a radially inner surface and on a radially outer surface of the rubber block, a flange recess in which one of the first and second flanges rest when the grounding shunt is installed within a respective one of the plurality of mbber blocks.

[0042] In some embodiments of the method, the flange recesses have a depth in a direction of the thickness of the mbber block such that, when the grounding shunt is installed within the rubber block, a surface of each first flange by which each such first flange contacts the inner wheel portion is substantially coplanar to the radially inner surface of the rubber block and a surface of each second flange by which each such second flange contacts the outer wheel portion is substantially coplanar to the radially outer surface of a respective one of the rubber blocks. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] FIG. 1 shows an embodiment from the prior art of a grounding shunt connected across a multi-part rail wheel.

[0044] FIG. 2 shows an embodiment from the prior art of the grounding shunt shown in FIG. 1, according to the prior art.

[0045] FIG. 3 schematically shows a cross-sectional view of embodiment of the grounding shunt connected across the multi-part rail wheel of FIG. 1.

[0046] FIG. 4 shows an embodiment of a grounding shunt capable of passing through the thickness of a rubber block in a multi-part rail wheel assembly.

[0047] FIG. 5 shows an embodiment of a rubber block that is installed between the inner and outer portions of a multi -part rail wheel, the rubber block being able to have the grounding shunt of FIG. 4 installed therein.

[0048] FIG. 6 shows an embodiment of the grounding shunt of FIG. 4 installed within the rubber block of FIG. 5.

[0049] FIG. 7 schematically shows a cross-sectional view of embodiment of the grounding shunt connected across a multi-part rail wheel.

[0050] FIGS. 8A-8D show respective side profiles of rubber blocks suitable for use in a multi-part rail wheel assembly.

[0051] FIG. 9 is an example embodiment showing the multi-part wheel assembly, including the rubber block and the grounding shunt, in an assembled configuration.

[0052] FIGS. 10A and 10B are cross-sectional views of the example embodiment of the multi-part wheel assembly of FIG. 9.

DETAILED DESCRIPTION

[0053] This disclosure relates to devices, systems, and methods for providing electrical grounding between two (e.g., inner and outer) railcar wheel portions 20, 30 that are physically and electrically isolated from each other by a plurality of electrically insulating rubber blocks 400 arranged circumferentially between the inner and outer wheel portions 20, 30 of a railcar wheel assembly 100. Unlike in such wheels 10 as are known from the prior art and shown in FIGS. 1-3, which require connections of a grounding shunt 60 external to the respective inner and outer wheel portions 20, 30, the presently disclosed electrical grounding devices comprise a flexible grounding shunt 600 that is installed through a thickness of one or more of (e.g., a plurality of, or all of) the rubber blocks 400, such that the grounding shunts 600 are substantially fully enclosed within a cavity formed through the rubber block 400 and enclosed on each end by the radial surfaces of the inner and outer wheel portions 20, 30, respectively, thereby substantially isolating the grounding shunts 600 from degradation due to environmental conditions (e.g., moisture, heat, etc.). Additionally, by virtue of being positioned internal to the railcar wheel assembly 100, the grounding shunts 600 also are in a position less likely to experience mechanical failure, whether from foreign object impacts or metal fatigue that occurs during normal use of such prior art electrical grounding shunts 60.

[0054] Unlike the rigid attachments of the end flanges (e.g., 64, FIG. 2) to the inner and outer wheel portions 20, 30 known from the prior art, the presently disclosed electrical grounding shunt 600 shown in at least FIG. 4 comprises a flange 640 at each end that is not rigidly connected to either of the inner or outer wheel portions 20, 30. The flange 640 may be formed as a substantially flat washer that is formed by any suitable forming process, such as, for example, stamping. As shown, each flange comprises a collar 660, or any other suitable structure, that connects each flange 640 to an end of a wire, or cable 620, of the grounding shunt 600 that extends between the opposing flanges 640 and defines substantially the entire length of the grounding shunt 600. In some embodiments, the collar 660 may be omitted and the cable 620 can be directly attached, for example, by brazing, to the flange 640. In some other embodiments, a hole may be formed through at least a thickness of the flange 640, such that the cable 620 passes through, or is disposed at least partially through (e.g., entirely through) the flange 640 to facilitate sufficiently precise attachment of the cable 620 to the flange 640. In embodiments having a hole entirely through the thickness of the flange 640, it is advantageous to subsequently remove (e.g., by grinding, cutting, melting, and the like) any portion of the cable 640 that extends beyond the outer surface of the flange 640 (e.g., prior to the protmding portion of the cable 640 being removed) to ensure a sufficient contact area between the flange 640 and whichever of the inner or outer wheel portions 20, 30 against which the flange 640 will be arranged when the grounding shunt 600 is in an installed position within the railcar wheel assembly 100.

[0055] In the embodiment shown, the flange 640 has a substantially planar outer surface area, but it may be advantageous in some embodiments for the flange 640 to have a curved profile that is substantially similar to, or the same as, the curvature of the radial surface of the inner or outer wheel portion 20, 30 against which the flange 640 will be in contact when installed in the railcar wheel assembly 100. In some embodiments, the flange 640 may have a thickness and/or be made of a sufficiently ductile material that the flange 640 will conform to (e.g., assume substantially the same shape as) the curvature of the inner or outer wheel portion 20, 30 against which the flange 640 will be in contact when installed in the railcar wheel assembly 100, such that the flange 640 is a substantially planar surface prior to installation and has a curvature (e.g., is bent) after being installed within the railcar wheel assembly 100. The cable 620 is formed as individual conductors (e.g., electrically conductive wires) that are braided together so that the cable 620 is flexible and can deflect within a deflection region 420 provided within the rubber block 400 more freely than a substantially similarly sized solid conductor wire, which would be significantly stiffer and would therefore suffer from premature wear and, ultimately, premature failure. The deflection region 420 can be provided along a length of, or one or more portions of the length of, the through-hole 410. The cable 620 may be formed from any suitably electrically conductive material, such as, for example, copper. The flanges 620 may be formed from any suitably electrically conductive material, such as, for example, steel or stainless steel. The flanges 640 may be secured to the cable 620 using any sufficiently rigid type of mechanical attachment, including, for example, brazing, crimping, welding, and the like. As such, while the flanges 640 are rigidly connected to the cable 620, the cable 620 remains flexible (e.g., can be bent and/or deflected into a curved, or nonlinear, shape) between the attachment regions defined generally by the collar 660 of each of the flanges 640. In some embodiments, the cable 620 and/or flanges 640 are plated with any suitable metallic coating to provide additional corrosion resistance. [0056] As shown in FIGS. 5 and 6, the example embodiment of one or more of the rubber blocks 400 of the railcar wheel assembly 100 has, on each side relative to the thickness direction thereof, a flange recess 440 formed therein to accommodate the flange 640 of the grounding shunt 600. In the embodiment shown, the flange recesses 440 are substantially axially aligned about a through-hole 410 passing through the entire thickness of the rubber block 400 and defining a passage through the thickness of the rubber block 400. The through-hole 410 has a larger diameter than the diameter of the cable 620 so that the cable 620 can flex, be bent, and/or be deformed by a compression of the rubber block 400 and, therefore, also of the grounding shunt 600, between the inner and outer wheel portions 20, 30 while the cable 620 is installed within the through-hole 410. The deflection region 420 can be provided along a length of, or one or more portions of the length of, the through-hole 410. In some embodiments, the deflection region 620 is oriented longitudinally to the length of extension of the through-hole 410 and is attached to the through-hole within the rubber block 400.

[0057] Due to the diameter of the through-hole 410 being larger than the diameter of the cable 620 passing through the through-hole 410 and also because the of the provision of the deflection region 420, the flexing, bending, and/or deformation of the cable 620 of the grounding shunt 600 during compression of the rubber block 400 as the inner wheel portion 20 moves relative to the outer wheel portion 30 adds no additional effective stiffness to the stiffness provided by the rubber block 400 itself. The relatively enlarged diameter of the through-hole 410 through the thickness of the rubber block 400 also acts to mitigate and/or reduce the creation of pinch points between the rubber block 400 and the cable 620, which could otherwise cause a decrease in the life of the grounding shunt 620 and/or of the rubber block 400. As such, the opposing flange recesses 440 are connected through the thickness of the rubber block 400 by the through-hole 410 formed therethrough.

[0058] In some embodiments, the flange recesses 440 may be axially offset from each other, such that the through-hole 410 is inclined, relative to the thickness direction of the rubber block 400. In such embodiments, it can be advantageous to have the cable 620 be connected to one or both of the flanges 640 at an inclined angle, such that, when the cable 620 is not in a deflected position, the cable 620 is vertically inclined, and not perpendicular, relative to one or both of the flanges 640. In some such embodiments, the engagement angle between the cable 620 and a first flange 640 at a first end of the grounding shunt 600 can be different from the engagement angle between the cable 620 and a second flange 640 at a second end of the grounding shunt 600. The flange recess 440 has a shape corresponding substantially to the perimeter of the flange 640, as measured, for example, in a plane perpendicular to the axial direction of the cable 620, to accommodate the contact surface of the flange 640 within the flange recess 440. The depth of the flange recess 440 is advantageously substantially the same as the thickness of the flange 640, excluding the height of the collar 660, but the depth of the flange recess 440 may be any value as long as the flange 640 will contact the corresponding radial contact surface of the inner or outer wheel portion 20, 30.

[0059] In order to allow for one of the flanges 640 to be able to be inserted through the through-hole 640, such that the grounding shunt passes through a thickness of the rubber block 400, lateral flange insertion slots 430 are formed on substantially opposing sides of the through-hole 410. Thus, each of the flange insertion slots 430 extend through the entire thickness of the rubber block 400. The dimensions of each flange insertion slot 430, including the through-hole 410, is are sufficiently large to allow for the flange 640, as well as the collar 660 and the cable 620 to pass therethrough during installation of the grounding shunt 600 in the rubber block 400. In some embodiments, it is advantageous for the flange insertion slots 430 and the through-hole 410 to have a width that is at least the width of the keyed portion 645 of the flanges. In some embodiments, the dimensions of the flange insertion slots 430 and the through-hole 410 remain substantially constant throughout the thickness of the mbber block 400. It is advantageous for the flange insertion slots 430 to be arranged on diametrically opposite sides of the through-hole 410 so that the dimensions of the flange insertion slots 430 can be minimized. In embodiments where the flanges 640 have a contoured (e.g., non-planar) surface, it is advantageous for the flange insertion slots 430 to be arranged offset about the through-hole 410 from a diametrically opposite arrangement, the degree of offset corresponding to the shape of the contour of the profile of the flange 640. In such embodiments, the flange insertion slots 430 may have a curved profile to better accommodate the curved profile shape of the flange 640. The grounding shunt 600 has a length that is substantially the same as the thickness of the uncompressed rubber block 400, such that the rubber block 400 is not pre-compressed by the grounding shunt 600 and the grounding shunt 600 does not protrude substantially from the inner and outer surfaces of the rubber block 400 prior to assembly of the railcar wheel assembly 100.

[0060] The rubber block 400 comprises a deflection region 420 that extends through at least a portion of the thickness of the rubber block 400. In some embodiments, the deflection region 420 can be provided to accommodate the portion of the cable 620 adjacent to and connected to the flange 640 that must flex, bend, and/or deflect when the flanges 640 of the grounding shunt 600 are compressed together during and after the installation of the rubber block(s) 400 between the inner and outer wheel portions 20, 30. In some embodiments, the deflection region 420 extends through the entire thickness of the rubber block 400. The deflection region 420 is formed as a radial protrusion from the through-hole, separate from the radial protrusions embodied by the flange insertion slots 430, into which the cable 620 can be deflected when the grounding shunt 600 is compressed and the effective length thereof is decreased when the rubber block 400 in which the grounding shunt 600 is inserted is installed within a railcar wheel assembly 100. In some embodiments, the deflection region 420 can be formed as a part of one or both of the flange insertion slots 430, such that flange insertion slots 430 into which the deflection region 420 is integrated can have a non-uniform cross-sectional width. When the rubber block 400 is compressed between the circumferential contact surfaces of the inner and outer wheel portions 20, 30 during assembly of the railcar wheel assembly 100, the grounding shunt 600 itself is also compressed, thereby resulting in a“bowing” or “bending” lateral deflection of the cable 620 into the deflection region 420. Depending on the dimensions of the deflection region 420, the length of the cable 620, and the degree of compression of the grounding shunt 600 within the rubber block 400, the cable 620 may experience a single bowing deflection or multiple deflections, an example of which can be seen in a sine wave. In some embodiments, an abrasion resistant coating can be applied over all, substantially all, or portions of the length of the cable 620 to reduce frictional wear between the cable 620 and the rubber block 400, such that the through-hole 410 is not substantially enlarged over a period of time by frictional contact between the cable 620 and the mbber block 400 during normal operation of the railcar wheel assembly 100. [0061] When the rubber block(s) 400 are compressed within the circumferential space between the inner and outer portions 20, 30, the flanges 640 of the grounding shunt 600 are pressed against the circumferential contact surfaces of the respective inner and outer wheel portions 20, 30, with the mbber block 400 exerting a radially outwardly directed pressure on the flanges 640 of the grounding shunt 600 to enable the flanges 640 to contact the inner or outer wheel portions 20, 30 over a larger surface area. Through this radially outwardly directed pressure acting on the flanges 640, a curvature may be induced, through either plastic or elastic deformation, in one or more of the flanges 640 that can have an outer surface that is substantially planar prior to compression of the grounding shunt 600 within the rubber block 400.

[0062] FIG. 7 is a schematic cross-sectional view of an example embodiment of a railcar wheel assembly 100 in an assembled state. To more clearly illustrate the arrangement of the elements in the railcar wheel assembly 100, gaps are shown between structural elements that are actually in contact with each other when in an assembled and non-deflected configuration of the railcar wheel assembly 100. The inner wheel portion 20 and the outer wheel portion 30 each comprise a channel having a“C” shape. The inner and outer wheel portions 20, 30 are arranged opposite each other to form a substantially rectangular region in which the rubber blocks 400 are installed. In an installed position, the opposing lateral flanges 640 of the channels of the inner and outer wheel portions 20, 30 are spaced apart from each other by the mbber block 400 to define a gap 50 that is continuous and uninterrupted along the entire outer circumference of the inner wheel portion 20 and along the entire inner circumference of the outer wheel portion 30. As such, the inner wheel portion 20 is isolated from, and does not contact, the outer wheel portion 30 during normal operation of the railcar wheel assembly 100. In some aspects, the outer wheel portion 30 may come in contact with the inner wheel portion 20 temporarily when a force of significant magnitude is imparted to the outer wheel portion 30 in a radially inwardly- directed direction, the force having a magnitude sufficiently large enough to cause a radial subset of each of the rubber blocks 400 adjacent to the location of the input force to be compressed to a sufficient degree that the inner and outer wheel portions 20, 30 contact each other, resulting in a temporary loss of the compliant aspects of the railcar wheel assembly. Just as the rubber block 400 exerts a radially-oriented force on the inner and outer wheel portions 20, 30 when compressed, so does the grounding shunt 600 when the cable 620 is deformed within the through-hole 410 due to the compression and installation of the rubber block 400 within the cavity formed between the channels of the inner and outer wheel portions 20, 30. This radially-oriented force exerted by the grounding shunt 600, pressing each flange 640 against the respective circumferential contact surface of the inner or outer wheel portions 20, 30, acts to ensure adequate electrical contact between the flange 640 and the circumferential contact surface of the inner or outer wheel portion 20, 30 against which the flange 640 is arranged.

[0063] FIGS. 8 A through 8D show various example profile shapes of rubber blocks 400A through 400D, into which the presently disclosed grounding shunt 600 can be integrated to provide the amount of electrical grounding disclosed herein. In addition to the examples shown herein, the rubber blocks 400 of a wheel 100 may be formed in any suitable profile shape, without limitation, and grounding shunts 600 may be installed within the rubber blocks 400 as disclosed elsewhere herein.

[0064] The number of rubber blocks 400 needed for a railcar wheel assembly can vary based on the load capable of being supported by the railcar and also based on the size of the railcar wheel assembly 100 itself. In any given railcar wheel assembly 100, as few as one and as many as all of the rubber blocks 400 that are needed to mechanically connect the inner and outer wheel portions 20, 30 together may be provided with the grounding shunts 600 disclosed herein, which pass through the bodies of all of the rubber blocks 400 that are provided with features for the insertion of such grounding shunts 600. In some embodiments, a single rubber block 400 may have a plurality of grounding shunts 600 installed therein, each such mbber block 400 having the same number of through-holes 410 and other associated features needed for installation and retention of the quantity of grounding shunts 600 that are to installed within such a mbber block 400. The number of grounding shunts 600 that may be installed in a single mbber block 400 will generally be determined by the size of the grounding shunts 600 being installed, the size of the rubber block 400, and the degree to which the mechanical properties of the mbber block 400 are altered, for example, made less stiff, by the inclusion of further grounding shunts 600 and their associated installation features. The number of grounding shunts 600 needed for a given railcar wheel assembly is dictated, for example, by the amount of electric current that must be dissipated, the uncompressed length of the grounding shunt 600, and the required amount and/or degree of flexibility of the cable 620 of the grounding shunt 600, which is largely dictated by the degree of compression the rubber block 400 will experience during installation and normal use of the railcar wheel assembly. The wire gauge of the cable 620 and the number of grounding shunts 600 should be selected to ensure that, given a known flow of electrical current that must be dissipated between the inner and outer wheel portions 20, 30 for a specified railcar, each grounding shunt 600 will experience a temperature rise of an acceptable magnitude, based on ambient environmental conditions in which the railcar wheel assembly will be operable, such that the rubber blocks 400 will not prematurely degrade from being exposed to excessively high temperatures, for example, temperatures in excess of 180 °F. As such, since railcar wheel assemblies typically must be capable of being used in arid climates, where temperatures could reach 120 °F, it may be advantageous to select a wire gauge and number of grounding shunts 600 so that the temperature rise due to current flowing through each grounding shunt 600 does not exceed 60 °F. It is particularly advantageous to apply a safety factor to the number of grounding shunts 600 and/or the wire gauge selected to ensure that failure of a predetermined number of electrical shunts will not cause catastrophic damage to the railcar wheel assembly, the railcar electrical system, occupants of the railcar, and the like.

[0065] FIGS. 9, 10A, and 10B show perspective assembly and cross-sectional views of an example embodiment of a multi-part wheel assembly, as also discussed elsewhere herein, including the rubber block 400 and the grounding shunt 600, in an assembled configuration. The inner wheel portion 20 is shown being spatially separated from the outer wheel portion 30 by a gap 50, with a plurality of rubber blocks 400 being installed between the inner and outer wheel portions 20, 30 to maintain the gap 50. FIGS. 10A and 10B are respective cross-sectional and detailed sectional views of the example multi-part wheel assembly embodiment shown in FIG. 9, specifically showing an installed position of the grounding shunt 600 providing an electrical connection between the inner and outer wheel portions 20, 30, through the rubber block 400.

[0066] A method of manufacturing an electrical grounding device, such as a grounding shunt (600, FIG. 7) within a rubber block (400, FIG. 7) for a railcar wheel assembly (100, FIG. 7) is provided. The method comprises: providing a rubber block 400 for providing vibration isolation between inner and outer wheel portions (20, 30, FIG. 7) of the railcar wheel assembly 100; forming a through-hole (410, FIG. 7) and at least one flange insertion slot (430, FIG. 5) connected to the through-hole 410 through a thickness of the rubber block 400; attaching electrically conductive flanges (640, FIG. 7) to opposing ends of an electrically conductive cable (620, FIG. 7) to form a grounding shunt 600; inserting a first flange 640 of the flanges 640 into the rubber block 400 via the at least one flange insertion slot 630 and the through-hole 410; and passing the first flange 640 through the thickness of the rubber block 400 so that the cable 620 is located within the through-hole 410 and a second flange 640 of the flanges 640 is on an opposite side of the rubber block 400 from the first flange 640, wherein the first and second flanges 640 are arranged proximate to an inner surface 402 and an outer surface 403, respectively, of the rubber block 400.

[0067] In some embodiments of the method, the cable 620 is a flexible cable comprising braided strands of electrically conductive wire. In some embodiments of the method, the through-hole 410 has a diameter that is larger than a diameter of the cable 620. In some embodiments of the method, the grounding shunt 600 has a length that is substantially similar to the thickness of the rubber block 400, as measured when the rubber block 400 is in an uncompressed state. In some embodiments of the method, the cable 620 is configured to bend within the through-hole 410 when the rubber block 400 is compressed so that effectively no stiffness is added to the rubber block 400 by the grounding shunt 600. In some embodiments of the method, the mbber block 400 is compressed and inserted within a channel formed between inner and outer wheel portions (20, 30, FIG. 7) of the railcar wheel assembly 100. In some embodiments of the method, the first and/or second flanges 640 comprise a keyed portion 645, and the at least one flange insertion slot 430 has a cross-sectional shape that is compatible with the keyed portion 645 and is radially connected to the through-hole 410. In some embodiments of the method, the first and second flanges 640 each comprise a collar (660, FIG. 4), which is rigidly connected to the cable 620 at the first and second ends thereof, respectively. In some embodiments, the method comprises forming flange recesses (440, FIG. 7) in the rubber block 400 at opposing ends of the through-hole 410; and arranging the first and second flanges 640 to rest in the flange recesses 440 when the grounding shunt 600 is installed within the rubber block 400. In some embodiments of the method, the flange recesses 440 are formed such that the first flange 640 is substantially coplanar to the radially inner surface (402, FIG. 7) of the rubber block 400 and the second flange 640 is substantially coplanar to the radially outer surface (403, FIG.7) of the rubber block 400. In some embodiments, the method comprises forming a deflection region (420, FIG. 5) in the rubber block 400, connected to, and oriented longitudinally with, the through-hole 410, such that, when the rubber block 400 is compressed by relative movement between the inner and outer wheel portions 20, 30, the cable 620 is flexed, bent, and/or deflected such that a portion of the cable 620 is located within the deflection region 420 while the rubber block 400 is compressed.

[0068] A method of electrically grounding a railcar wheel assembly (100, FIG. 7) is provided. The method comprises: arranging an outer wheel portion 30 concentrically around an inner wheel portion 20 to define a channel between the inner and outer wheel portions 20, 30 of the railcar wheel assembly 100; inserting a plurality of rubber blocks 400 within the channel radially about the railcar wheel assembly 100, wherein one or more of the plurality of rubber blocks 400 are electrical grounding devices comprising a rubber block 400 comprising a through-hole 410; and a grounding shunt 600 comprising a cable 620 that passes or is disposed within and through the through-hole 410; a first flange 640 attached to a first end of the cable 620; and a second flange 640 attached to a second end of the cable 620; and wherein a radial distance between the inner and outer wheel portions 20, 30 is smaller than a thickness of the plurality of rubber blocks 400, so that the plurality of rubber blocks 400 are compressed within the channel; and conducting an electrical current between the inner wheel portion 20 and the outer wheel portion 30 via each of the grounding shunts 600.

[0069] In some embodiments of the method, each cable 620 is a flexible cable 620 comprising braided strands of electrically conductive wire. In some embodiments of the method, each through-hole 410 has a diameter that is larger than a diameter of the cable 620 arranged therein. In some embodiments of the method, each grounding shunt 600 has a length that is substantially similar to a thickness of the plurality of rubber blocks 400, as measured when the rubber blocks 400 are in an uncompressed state. In some embodiments of the method, each cable 620 is configured to bend within the through-hole 410 when the rubber block 400 is compressed so that no effective stiffness is added to the rubber block 400 by the grounding shunt 600. In some embodiments, the method comprises: forming a keyed portion 645 on the first and/or second flanges 640; forming at least one flange insertion slot 430 in each rubber block 400, the at least one flange insertion slot 430 being radially connected to the through-hole 410, and inserting the first flange 640 and/or the second flange 640 through the rubber block 400 so that the cable 620 is installed in the through-hole 410. In some embodiments of the method, the first and second flanges each comprise a collar 660, which is rigidly connected to the cable 620 and the first and second ends thereof, respectively. In some embodiments of the method, each rubber block 400 comprises a flange recess 440 on the radially inner and outer surfaces 402, 403 thereof, each flange recess 440 being configured such that the first or second flanges 640 rest therein when each grounding shunt 600 is installed within a respective one of the plurality of rubber blocks 400. In some embodiments of the method, the flange recesses 440 are formed such that each first flange 604 is substantially coplanar to the radially inner surface 402 of the rubber block 400 and each second flange 640 is substantially coplanar to the radially outer surface 403 of the rubber block 400. In some embodiments, the method comprises forming a deflection region (420, FIG. 5) in the rubber block 400, connected to, and oriented longitudinally with, the through- hole 410, such that, when the rubber block 400 is compressed by relative movement between the inner and outer wheel portions 20, 30, the cable 620 is flexed, bent, and/or deflected such that a portion of the cable 620 is located within the deflection region 420 while the rubber block 400 is compressed.

[0070] The embodiments described herein are examples only and are not limiting. Many variations and modifications of the systems, apparatus, and processes described herein are possible and are within the scope of the disclosure. Accordingly, the scope of protection is not limited to the embodiments described herein, but is only limited by the claims that follow, the scope of which shall include all equivalents of the subject matter of the claims.

Claims

CLAIMS What is claimed is:

1. An electrical grounding device for a railcar wheel assembly, the electrical grounding device comprising:

a rubber block comprising a through-hole formed through an entirety of a thickness of the rubber block, wherein the rubber block is configured to be compressively arranged between an inner wheel portion and an outer wheel portion of a railcar wheel assembly and provide vibrational isolation between the inner and outer wheel portions; and

a grounding shunt comprising:

a cable disposed through the through-hole;

a first flange attached to a first end of the cable; and

a second flange attached to a second end of the cable; wherein the first flange is configured to electrically contact the inner wheel portion and the second flange is configured to electrically contact the outer wheel portion; and

wherein the cable is configured to conduct an electrical current between the inner wheel portion and the outer wheel portion through the rubber block.

2. The electrical grounding device of claim 1 , wherein the cable is a flexible cable comprising braided strands of electrically conductive wire.

3. The electrical grounding device of claim 2, wherein the through-hole has a diameter that is larger than a diameter of the cable.

4. The electrical grounding device of claim 3, wherein the grounding shunt has a length that is substantially similar to an uncompressed thickness of the rubber block.

5. The electrical grounding device of claim 4, wherein the cable is configured to flex, bend, and/or deflect within the through-hole when the mbber block is compressed by relative movement between the inner and outer wheel portions, so that effectively no stiffness is added to the rubber block by the grounding shunt.

6. The electrical grounding device of claim 1, wherein:

the first and/or second flanges comprise one or more keyed portions, at least one flange insertion slot is provided in the rubber block, the at least one flange insertion slot being radially connected to the through-hole, and

the at least one flange insertion slot is configured such that the first and/or second flanges can be inserted through the rubber block so that the cable is installed in the through-hole only when the first and/or second flanges are oriented such that the one or more keyed portions can pass through the at least one flange insertion slot.

7. The electrical grounding device of claim 1, wherein the first and second flanges each comprise a collar, each collar being rigidly connected to the cable at one of the first and second ends thereof.

8. The electrical grounding device of claim 1, wherein the rubber block comprises, on both a radially inner surface and on a radially outer surface of the rubber block, a flange recess configured such that one of the first and second flanges rest within the flange recess on whichever of the radially inner or outer surfaces that the first or second flange is arranged when the grounding shunt is installed within the rubber block.

9. The electrical grounding device of claim 8, wherein the flange recesses have a depth in a direction of the thickness of the rubber block such that, when the grounding shunt is installed within the rubber block, a surface of the first flange by which the first flange contacts the inner wheel portion is substantially coplanar to the radially inner surface of the rubber block and a surface of the second flange by which the second flange contacts the outer wheel portion is substantially coplanar to the radially outer surface of the rubber block.

10. An electrical grounding system for a railcar wheel assembly, the electrical grounding system comprising:

an inner wheel portion; an outer wheel portion arranged concentrically around the inner wheel portion to define a channel between the inner and outer wheel portions;

a plurality of rubber blocks, each of which comprises a through-hole formed through an entirety of a thickness of the rubber block, wherein the rubber blocks are arranged radially about the railcar wheel assembly within the channel by compression to provide vibrational isolation between the inner and outer wheel portions and to space the inner wheel portion apart from the outer wheel portion, thereby defining an annular gap between the inner and outer wheel portions when the inner and outer wheel portions are in an undeflected position; and

a plurality of grounding shunts, each of the grounding shunts being arranged to pass through a corresponding through-hole of one of the plurality of rubber block, each of the grounding shunts comprising:

a cable disposed through the through-hole;

a first flange attached to a first end of the cable; and

a second flange attached to a second end of the cable; wherein each of the first flanges is configured to electrically contact the inner wheel portion and each of the second flanges is configured to electrically contact the outer wheel portion; and

wherein each cable is configured to conduct an electrical current between the inner wheel portion and the outer wheel portion through the rubber block in which the cable is disposed.

11. The electrical grounding system of claim 10, wherein each cable is a flexible cable comprising braided strands of electrically conductive wire.

12. The electrical grounding system of claim 11, wherein each through-hole has a diameter that is larger than a diameter of the cable arranged therein.

13. The electrical grounding system of claim 12, wherein each grounding shunt has a length that is substantially similar to an uncompressed thickness of the rubber block through which the grounding shunt is installed.

14. The electrical grounding system of claim 13, wherein each cable is configured to flex, bend, and/or deflect within the through-hole when the rubber block is compressed by relative movement between the inner and outer wheel portions, so that effectively no stiffness is added to the rubber block by the grounding shunt.

15. The electrical grounding system of claim 10, wherein:

the first and/or second flanges comprise one or more keyed portions, at least one flange insertion slot is provided in each rubber block, the at least one flange insertion slot being radially connected to the through-hole, and

16. The electrical grounding system of claim 10, wherein the first and second flanges each comprise a collar, each collar being rigidly connected to the cable at one of the first and second ends thereof.

17. The electrical grounding system of claim 10, wherein each rubber block comprises, on both a radially inner surface and on a radially outer surface of the rubber block, a flange recess configured such that one of the first and second flanges rest within the flange recess on whichever of the radially inner or outer surfaces that the first or second flange is arranged when the grounding shunt is installed within a respective one of the plurality of rubber blocks.

18. The electrical grounding system of claim 17, wherein the flange recesses have a depth in a direction of the thickness of the rubber block such that, when the grounding shunt is installed within the rubber block, a surface of each first flange by which each such first flange contacts the inner wheel portion is substantially coplanar to the radially inner surface of a respective one of the rubber blocks and a surface of each second flange by which each such second flange contacts the outer wheel portion is substantially coplanar to the radially outer surface of a respective one of the rubber blocks.

19. A method of manufacturing an electrical grounding device for a railcar wheel assembly, the method comprising:

providing a rubber block that can be compressively arranged between an inner wheel portion and an outer wheel portion of a railcar wheel assembly and provide vibrational isolation between the inner and outer wheel portions;

forming a through-hole and at least one flange insertion slot radially connected to the through-hole through an entirety of a thickness of the rubber block;

forming a grounding shunt by attaching a first electrically conductive flange to a first end of an electrically conductive cable and by attaching a second electrically conductive flange to a second end of the cable, wherein the first end is an opposite end of the cable from the second end;

inserting the first flange into the rubber block via the at least one flange insertion slot and the through-hole; and

passing the first flange through the thickness of the mbber block, so that the cable is located substantially entirely within the through-hole and the second flange is on an opposite side of the rubber block from the first flange, wherein the first and second flanges are arranged proximate to a respective outer surface of the rubber block when the grounding shunt is installed within the mbber block.

20. The method of claim 19, wherein the cable is a flexible cable comprising braided strands of electrically conductive wire.

21. The method of claim 20, wherein the through-hole has a diameter that is larger than a diameter of the cable.

22. The method of claim 21, wherein the grounding shunt has a length that is substantially similar to an uncompressed thickness of the mbber block.

23. The method of claim 22, wherein the cable is configured to flex, bend, and/or deflect within the through-hole when the mbber block is compressed by relative movement between the inner and outer wheel portions, so that effectively no stiffness is added to the rubber block by the grounding shunt.

24. The method of claim 19, wherein the mbber block is compressed and inserted within a channel formed between the inner and outer wheel portions of the railcar wheel assembly.

25. The method of claim 19, wherein:

the first and/or second flanges comprise one or more keyed portions, and the at least one flange insertion slot has a cross-sectional shape that is compatible with the one or more keyed portions, such that the cable can only be installed in the through-hole when the first and/or second flanges are oriented such that the one or more keyed portions can pass through the at least one flange insertion slot.

26. The method of claim 19, wherein the first and second flanges each comprise a collar, each collar being rigidly connected to the cable and the first and second ends thereof.

27. The method of claim 19, comprising:

forming flange recesses in the rubber block at opposing ends of the through- hole, on respective radially inner and outer surfaces of the rubber block; and

arranging the first and second flanges within one of the flange recesses when the grounding shunt is installed within the mbber block.

28. The method of claim 27, wherein the flange recesses have a depth in a direction of the thickness of the mbber block, such that, when the grounding shunt is installed within the rubber block, a surface of the first flange by which the first flange contacts the inner wheel portion is substantially coplanar to the radially inner surface of the mbber block and a surface of the second flange by which the second flange contacts the outer wheel portion is substantially coplanar to the radially outer surface of the rubber block.

29. A method of electrically grounding a railcar wheel assembly, the method comprising:

arranging an outer wheel portion concentrically around an inner wheel portion to define a channel between the inner and outer wheel portions of the railcar wheel assembly;

inserting a plurality of rubber blocks within the channel radially about the railcar wheel assembly, wherein one or more of the plurality of rubber blocks are electrical grounding devices according to claim 1 and wherein a radial distance between surfaces by which the rubber blocks contact the inner and outer wheel portions is smaller than a thickness of the rubber blocks, so that the plurality of rubber blocks are compressed within the channel; and

conducting an electrical current between the inner wheel portion and the outer wheel portion via the grounding shunts to dissipate and electrical charge generated by a railcar to which the railcar wheel assembly is rotatably attached.

30. The method of claim 29, wherein each cable is a flexible cable comprising braided strands of electrically conductive wire.

31. The method of claim 30, wherein each through-hole has a diameter that is larger than a diameter of the cable arranged therein.

32. The method of claim 31, wherein each grounding shunt has a length that is substantially similar to an uncompressed thickness of the rubber block through which the grounding shunt is installed.

33. The method of claim 32, wherein each cable is configured to flex, bend, and/or deflect within the through-hole when the rubber block is compressed by relative movement between the inner and outer wheel portions, so that effectively no stiffness is added to the rubber block by the grounding shunt.

34. The method of claim 29, comprising:

forming one or more keyed portions on the first and/or second flanges;

forming at least one flange insertion slot in each rubber block, the at least one flange insertion slot being radially connected to the through-hole, and

inserting the first flange and/or the second flange through one of the rubber blocks, so that the cable is installed in the through-hole, wherein the cable can only be installed in the through-hole when the first and/or second flanges are oriented such that the one or more keyed portions can pass through the at least one flange insertion slot.

35. The method of claim 29, wherein the first and second flanges each comprise a collar, each collar being rigidly connected to the cable at one of the first and second ends thereof.

36. The method of claim 29, wherein each rubber block comprises, on both a radially inner surface and on a radially outer surface of the rubber block, a flange recess in which one of the first and second flanges rest when the grounding shunt is installed within a respective one of the plurality of rubber blocks.

37. The method of claim 36, wherein the flange recesses have a depth in a direction of the thickness of the rubber block such that, when the grounding shunt is installed within the rubber block, a surface of each first flange by which each such first flange contacts the inner wheel portion is substantially coplanar to the radially inner surface of the rubber block and a surface of each second flange by which each such second flange contacts the outer wheel portion is substantially coplanar to the radially outer surface of a respective one of the rubber blocks.