System and method for monitoring the status of one or more components of an electrical machine

Example brush holder assemblies of an electric machine are disclosed. An example brush holder assembly of an electric machine includes a carbon brush including an upper surface and a lower surface opposite the upper surface. The brush holder assembly also includes one or more lead wires extending out of the carbon brush at an insertion point on the upper surface and a first cavity extending into the carbon brush from the upper surface at a location spaced away from the insertion point of the one or more lead wires and unobstructed by the one or more lead wires.

TECHNICAL FIELD

The disclosure generally relates to monitoring systems for monitoring brushes and brush holder assemblies that may be used in electrical devices and/or slip ring assemblies. More specifically, the disclosure relates to monitoring apparatus, assemblies, systems and methods of monitoring the wear of a brush in a brush holder assembly and/or the condition of a slip ring of an electrical device using a sensor.

BACKGROUND

A purpose of a brush in an electrical device is to pass electrical current from a stationary contact to a moving contact surface, or vice versa. Brushes and brush holders may be used in electrical devices such as electrical generators, electrical motors, and/or slip ring assemblies, or sliding connection applications, for example, slip ring assemblies on a rotating machine such as a rotating crane or a linear sliding connection on a monorail. Brushes in many electrical devices are blocks or other structures made of conductive material, such as graphite, carbon graphite, electrographite, metal graphite, or the like, that are adapted for contact with a conductive surface or surfaces to pass electrical current. Electrically conductive leads or shunts extend from the brush to provide an electrical pathway to and/or from the brush from another conductive member.

In some designs, a brush box type brush holder, or other type of brush holder, may be used to support a brush in contact with a moving contact surface of an electrical device during operation. The brush and brush box may be designed such that the brush can slide within the brush box to provide for continuing contact between the brush and the moving contact surface contacted by the brush. During operation an anomalous and/or threshold condition may occur, which may be indicative that one or more components of the electrical device may need to be replaced, one or more components of the electrical device may require inspection or attention, and/or maintenance may need to be performed. For example, an anomalous and/or threshold condition may indicate that one or more of a brush, brush holder, spring, shunt, commutator, collector ring, and/or other component may need to be replaced, one or more of a brush, brush holder, spring, shunt, commutator, collector ring, and/or other component may need to be inspected, and/or maintenance may need to be performed. It would be advantageous to monitor one or more components of an electrical device in order to observe the occurrence of an anomalous and/or threshold condition. Furthermore, it would be advantageous to alert an operator and/or technician of the occurrence of an anomalous and/or threshold condition and/or schedule technician intervention.

SUMMARY

The disclosure is directed to monitoring apparatus, assemblies, systems and methods of monitoring the wear of a brush in a brush holder assembly and/or the condition of a slip ring of an electrical device using a sensor.

An example brush holder assembly of an electric machine includes a carbon brush including an upper surface and a lower surface opposite the upper surface. The brush holder assembly also includes one or more lead wires extending out of the carbon brush at an insertion point on the upper surface and a first cavity extending into the carbon brush from the upper surface at a location spaced away from the insertion point of the one or more lead wires and unobstructed by the one or more lead wires.

Alternatively or additionally, further comprising a spacer coupled to the carbon brush, the spacer including a first projection configured to releasably engage within the first cavity.

Alternatively or additionally, further comprising a wear state monitor coupled to the spacer, wherein the wear state monitor is designed to measure an angular displacement of the wear state monitor as the wear state monitor rotates.

Alternatively or additionally, wherein the brush further includes a length measured from the upper surface to the lower surface, wherein the length is diminished from an initial length as the lower surface of the carbon brush wears away during use and wherein the measured angular displacement of the wear state monitor correlates to the diminished length of the carbon brush.

Alternatively or additionally, wherein engagement of the first projection in the first cavity of the carbon brush is configured to retain the spacer in a fixed relationship with the carbon brush.

Alternatively or additionally, wherein the first projection extends away from a bottom surface of the spacer.

Alternatively or additionally, wherein the first cavity includes a channel extending along the upper surface of the carbon brush, and wherein the first projection is configured to mate with and insert into the channel.

Alternatively or additionally, wherein the first cavity includes a first tapered surface, and wherein the first projection includes a second tapered surface designed to mate with the first tapered surface of the first cavity.

Alternatively or additionally, wherein the carbon brush further comprises a second cavity extending into the carbon brush from the upper surface at a location spaced away from the insertion point of the one or more lead wires and unobstructed by the one or more lead wires, wherein the second cavity is spaced away from the first cavity.

Alternatively or additionally, wherein the spacer further comprises a second projection configured to releasably engage within the second cavity.

Alternatively or additionally, wherein the first projection and the second projection are designed to engage the carbon brush simultaneously, and wherein the engagement of the first projection and the second projection with the first and second cavities of the carbon brush is configured to retain the spacer in a fixed relationship with the carbon brush.

Alternatively or additionally, wherein both the first projection and the second projection extend away from a bottom surface of the spacer.

Alternatively or additionally, wherein the shape of both the first projection and the second projection is designed to mate with the first cavity and the second cavity.

Another example system for monitoring the wear state of a carbon brush includes a brush holder assembly. The brush holder assembly includes a carbon brush including an upper surface, a lower surface opposite the upper surface, and a length measured from the upper surface to the lower surface, wherein the length is diminished from an initial length as the lower surface of the carbon brush wears away during use. The brush holder assembly also includes a spring having a first end and a second end, and a coiled portion. Further, the brush holder assembly includes a wear state monitor positioned within the coiled portion of the spring, the wear state monitor including a sensor, wherein the sensor is configured to measure an angular displacement of the wear state monitor as the wear state monitor rotates. Additionally, the brush assembly further includes a spacer positioned between the coiled portion of the spring and the upper surface of the carbon brush, the spacer including a first projection extending away from a bottom surface of the spacer, wherein the carbon brush includes a first cavity extending into the carbon brush from the upper surface, and wherein the first cavity receives the first projection therein.

Alternatively or additionally, further comprising a lead wire having a first end and a second end extending away from the first end, wherein the first end extends into the carbon brush at an insertion point at the upper surface of the carbon brush and spaced away from the first cavity.

Alternatively or additionally, wherein engagement of the first projection within the first cavity is configured to retain the spacer in a fixed relationship with the carbon brush.

Alternatively or additionally, wherein the measured angular displacement of the wear state monitor correlates to an amount of diminution in the length of the carbon brush.

Alternatively or additionally, wherein the first cavity includes a channel extending along the upper surface of the carbon brush, and wherein the first projection is configured to mate with and insert into the channel.

Alternatively or additionally, wherein the first cavity includes a tapered surface, and wherein the first projection includes a tapered surface designed to mate with the tapered surface of the first cavity.

Alternatively or additionally, wherein the carbon brush further comprises a second cavity extending into the carbon brush from the upper surface of the carbon brush, wherein the second cavity is spaced away from the first cavity.

Alternatively or additionally, wherein the spacer further comprises a second projection extending into the second cavity.

Alternatively or additionally, wherein the first projection and the second projection are designed to engage the carbon brush simultaneously, and wherein the engagement of the first projection and the second projection with the carbon brush is configured to retain the spacer in a fixed relationship with the carbon brush.

Alternatively or additionally, wherein both the first projection and the second projection extend away from a bottom surface of the spacer.

Alternatively or additionally, wherein the bottom surface of the spacer is juxtaposed with the upper surface of the carbon brush when the first and second projections are positioned in the first and second cavities.

Another example assembly for a brush holder assembly of an electrical device includes a carbon brush including an upper surface, a lower surface opposite the upper surface, and a length measured from the upper surface to the lower surface. The brush assembly also includes one or more lead wires extending out of the carbon brush at an insertion point on the upper surface and first and second cavities extending into the carbon brush from the upper surface at a location spaced away from the insertion point of the one or more lead wires and unobstructed by the one or more lead wires. Further, the brush assembly includes a spacer having first and second projections extending from a lower surface of the spacer wherein the first and second projections are configured to be inserted into the first and second cavities when the lower surface of the spacer is juxtaposed with the upper surface of the carbon brush.

The above summary of some embodiments, aspects, and/or examples is not intended to describe each embodiment or every implementation of the present disclosure. The figures and the detailed description which follows more particularly exemplify these embodiments.

DETAILED DESCRIPTION

FIG. 1illustrates an exemplary brush monitoring system100that may include a brush holder assembly110, a site monitor120and/or a remote monitoring site140including a remote monitoring device150,160. In some cases, the brush holder assembly110may substantially resemble a brush holder assembly as described in U.S. Pat. No. 7,034,430, entitled “BRUSH HOLDER APPARATUS, BRUSH ASSEMBLY, AND METHOD”, which is herein incorporated by reference in its entirety. However, the illustrative brush monitoring system100may be amenable to any of various brush holder assembly configurations. Thus, the intention is that the illustrative brush monitoring system100may be used in conjunction with any desired brush holder assembly configurations of an electrical device, such as an industrial electrical generator. For example, the illustrative brush monitoring system100may be used with brush holder assemblies, brush holders and/or brushes disclosed in U.S. Pat. Nos. 6,731,042; 5,753,992; 5,621,262; 5,463,264; 5,397,952; and 5,256,925; each of which is incorporated herein by reference.

FIG. 1illustrates a brush24including a first end surface34and a second end surface35and a length extending therebetween. The second end surface35may be in electrical contact with a conductive surface12of a rotating component15of an electrical machine (e.g., a collector ring, a slip ring, or a commutator) and conduct electrical current therefrom. Further,FIG. 1illustrates that, in some examples, one or more sides of the brush24may be surrounded by a brush holder22(e.g., a brush box), whereby the brush holder22may include a plurality of guiding surfaces for guiding linear or longitudinal movement of the brush24toward the conductive surface12of the rotating component15. In other words, the brush24may translate linearly within an aperture defined by the plurality of guiding surfaces of the brush holder22as the brush24wears. In some embodiments it is contemplated that the brush holder22may not take on the form of a box, but may include one or a plurality of guiding surfaces, such as channels, posts or columns, abutting and/or encompassing one or more sides of the brush24and/or extending into or through the brush24, or a portion thereof, for guiding linear or longitudinal movement of the brush24.

FIG. 1further illustrates that the brush holder22may be secured to a mounting beam26configured and adapted to be mounted to another structure, such as a mounting block70. The brush holder assembly110may be configured to place the brush24in contact with the conductive surface12, such as the surface of the rotating component15of the electrical machine. The brush24may extend from the lower edge of the brush holder22such that the second end surface35of the brush24engages the conductive surface12. The mounting beam26may include an over-center engagement mechanism, a slotted or channeled engagement mechanism for sliding engagement, or other mechanism for easily engaging and disengaging the brush24from a conductive surface12. In other embodiments, the brush holder assembly110may include a brush holder22rigidly mounted to another structure holding the brush holder22stationary, or mounted to another structure in any desired arrangement. For example, in some embodiments the brush holder22may be bolted or welded to a stationary structure. Some such brush holders are disclosed in U.S. Pat. Nos. 6,731,042; 5,753,992; 5,621,262; 5,463,264; 5,397,952; and 5,256,925; which are incorporated herein by reference.

As shown inFIG. 1, the mounting beam26may include an upper beam member27and a lower beam member28hingedly or pivotedly coupled to one another. When the upper beam member27and the lower beam member28are aligned with one another (e.g., the longitudinal axis of the upper beam member27is parallel with the longitudinal axis of the lower beam member28), the brush holder22may be considered to be in an engaged, or locked, position such that the brush24may be contiguous with or in contact with the conductive surface12. When the upper beam member27is tilted from the lower beam member28(e.g., the longitudinal axis of the upper beam member27is oblique to the longitudinal axis of the lower beam member28), the brush holder22may be considered to be in a disengaged, or unlocked, position such that the brush24may be non-contiguous with, spaced from, or otherwise not in direct electrical contact with the conductive surface12. The mounting beam26may be removably coupled to the mounting block70during operation. In some embodiments, the mounting beam26may slidably engage with, interlock with, or otherwise be removably coupled to the mounting block70. The mounting block70may be coupled to, secured to, or otherwise extend from another structure which maintains the mounting block70stationary with respect to (i.e., a fixed distance from) the conductive surface12, for example.

In some embodiments, a handle21may be attached to the brush holder22to facilitate engagement and disengagement of the brush24from the conductive surface12. For example, the handle21may be attached to the upper beam member27such that movement of the handle21actuates (e.g., pivots, slides, releases) the upper beam member27relative to the lower beam member28. The handle21may be a removable handle or the handle21may be permanently attached to the upper beam member27or another portion of the brush holder22.

FIG. 1further illustrates that the brush holder assembly110may include a wear state monitor50and a spacer30. The spacer30may be attached to the first end surface34of the brush24. Additionally,FIG. 1illustrates that the wear state monitor50may be coupled to a spring29. In some examples, a portion of the spring29may be coiled around a portion of the wear state monitor50, with an elongate portion of the spring extending from the coiled portion. Further detailed discussion of the wear state monitor50, the spacer30and the spring29follows below.

In some examples the wear state monitor50may include one or more sensors which collect and/or measure a variety of parameters corresponding to the “wear state” of the brush24. For example, the wear state monitor50may include one or more sensors which measure and/or communicate the extent to which the brush24wears away while in contact with the conductive surface12of the rotating component15. In some examples, the sensor(s) may also measure the vibration and/or temperature of the brush holder assembly110(including individual components thereof) and/or the brush24, and/or electrical current passing through the brush24, for instance.

In some cases, the wear state monitor50may be positioned adjacent to a surface of a component of the brush holder assembly110, different than the spring29. For example, the wear state monitor50may be positioned on or adjacent to the brush holder22, the lower beam member28, the upper beam member27and/or on or adjacent to the handle21of the brush holder assembly110. In some cases, the wear state monitor50may be permanently and/or removably incorporated into a portion of the handle21or other component of the brush holder assembly110. In some examples, the wear state monitor50may be free from the spring29.

As described above, in some examples the wear state monitor50may be mounted adjacent a surface of the spring29or otherwise within the spring29, such as within a coiled portion of the spring29. The spring29may include a constant force spring, which provides tension to the brush24, the wear state monitor50or both the brush24and the wear state monitor50to bias the brush24toward and in contact with the conductive surface12of the rotating component15. In other words, the spring29may include a coiled portion designed to provide a force to engage the brush24with a rotating component of an electrical machine, such as a slip ring, a commutator, and the like.

In some examples, the spring29may be attached to a portion of the brush holder22and/or the mounting beam26of the brush holder assembly110. In some instances, a first end32of the spring29may be removably coupled to the brush holder and/or the mounting beam26with an elongate portion of the spring29extending along a side surface of the brush24, between the brush24and the mounting beam26. Thus, in some embodiments, an elongate portion of the spring29may extend along one side surface of the brush24between the brush24and the mounting beam26of the brush holder assembly110up to the coiled portion of the spring29positioned above the upper surface34of the brush24. The opposite, second end33of the spring29may be located at the interior of the coiled portion of the spring29.

In some cases, the wear state monitor50may also include one or more indicators55(e.g., one or more light emitting diodes (LEDs), a speaker, or a combination of LEDs and/or speakers) for communicating wear state information to a user. In some instances, the wear state monitor50may be capable of communicating information about the wear state of the brush24and/or the rotating component15to a user via the indicators55. In some cases, the wear state monitor50may be capable of receiving messages from an external device, such as the site monitor120and/or a programming device located at the same site or at a remote location (e.g., a computer150, a tablet160, a smart phone, etc.). The messages may include commands, such as commands to send wear state information about the brush24and/or the rotating component15, or commands for modifying information used by the wear state monitor50. For example, a user may desire to modify one or more thresholds used to determine the wear state information of the brush24and/or the rotating component15, and/or to reprogram the wear state monitor50by downloading instructions, tables and/or the like.

As described above, in some examples the wear state monitor50may measure and/or collect information regarding the wear state of the brush24. In particular, the wear state monitor50may be designed to measure and collect information regarding the extent to which the second end surface35of the brush24contacting the conductive surface12has worn away (i.e., the amount of diminution in length of the brush24at some time from its initial length when installed in the brush holder assembly110). It can be appreciated that as the second end surface of the brush24maintains contact with the rotating component15, the second end surface35of the brush24may wear away, thereby shortening the overall length of the brush24.

As described above, the spring29may apply a force to the brush24which is directed linearly along the aperture defined by the brush holder22. Further, as the brush24decreases in length within the brush holder22, the wear state monitor50may rotate within the coil of the spring29while the axis of rotation of the wear state monitor50translates linearly with linear translation of the brush24toward the conductive surface12of the rotating component15. Additionally, a sensor may be positioned within the wear state monitor50and may measure and collect data representing the extent (e.g., total angular distance and/or total arc length) of rotation of the wear state monitor50from its initial position when the brush24was installed in the brush holder assembly110, or any other duration desired. It can be appreciated that the amount of rotation measured by the sensor (positioned within the wear state monitor50) may be equivalent, proportional, or otherwise representative of the linear or longitudinal movement of the brush24as it translates (e.g., shortens) within the brush holder22, and thus equivalent, proportional, or otherwise representative of the amount of diminution of the brush24from its initial length.

In some cases, the sensor may associate the rotation of the wear state monitor50with a wear state of the brush24and/or a wear state of the conductive surface12and/or the rotating component15. The value (e.g., amount of rotation of the wear state monitor50) measured by the sensor may correspond to the position of the first end of the brush24relative to the conductive surface12of the rotating component15. In some cases, the value measured by the sensor may correspond to a value obtained over any desired time interval or duration of wear of the brush24. It can be appreciated that the value (e.g., amount of rotation of the wear state monitor50from its initial position) may be compared to one or more predetermined threshold values to determine a wear state of the brush24and/or other diagnostic information about the machine.

For example, in some cases the wear state monitor50(including the sensor positioned therein) may be configured to monitor a vibration of the brush24. Vibration of the brush24may be due to one or more imperfections, wear or other deformation of the rotating component15of the electrical machine. For example, a slip ring may deform or may wear unevenly to cause one or more portions of the slip ring to be out of round. As the brush24encounters these defects at one or more positions during a revolution of the rotating component15, the defects may cause the brush24to vibrate at a rate corresponding to the rotation speed and/or the number of defects at the conductive surface12of the rotating component15(e.g., a slip ring, a commutator, etc.). In some examples, the transient angular displacement of the wear state monitor50may correspond and/or correlate to a threshold change in vibration or other deformation of the rotating component15of the electrical machine. As used herein, “transient angular displacement” means momentary change in the rotational orientation of the wear state monitor50in an oscillating fashion. Therefore, in some examples, information corresponding to the transient angular displacement (which may correspond to a threshold change in vibration) of the wear state monitor50may be collected and transmitted to the site monitor120to determine if the brush24is experiencing excessive vibration.

Similarly, it can be appreciated that the sensor positioned within the wear state monitor50(or a separate temperature sensor) may measure and collect information associated with a temperature of the brush24, other components of the electrical machine and/or the ambient air temperature surrounding the brush holder assembly110. Further, the collected temperature values may be monitored and/or compared to one or more predetermined temperature thresholds, whereby the temperature thresholds may trigger the sensor to send a signal to the site monitor120indicative of the need for inspection and/or maintenance to be performed on one or more components of the electrical machine. For example, in some instances, the temperature threshold may be set to trigger a signal when the measured temperature exceeds a threshold temperature, such as a threshold temperature of 125 degrees Celsius. In other words, when the temperature sensor measures a temperature (e.g., ambient air temperature, temperature of a component of the electrical machine, etc.) greater than 125 degrees Celsius, it may send a signal to the site monitor120alerting personnel of the need for inspection and/or maintenance to be performed on one or more components of the electrical machine. In other instances, the threshold temperature may be set in a range of 100 degrees Celsius to 140 degrees Celsius, in a range of 110 degrees Celsius to 130 degrees Celsius, or in a range of 120 degrees Celsius to 130 degrees Celsius, for example.

In some cases, the site monitor120may be positioned near the electrical machine to monitor the wear state of one or more brush holder assemblies110and/or the wear state of the slip ring or other rotating component of the electrical machine. The site monitor120may be capable of monitoring the wear states of the brush24of the brush holder assembly110. In some cases, the site monitor120may be capable of monitoring the movement of the brushes24of two or more brush holder assemblies110associated with one or more electrical machines. For example, the site monitor120may be communicatively coupled to one or more, or a plurality of wear state monitors50associated with a particular electrical machine, such as the wear state monitor50of the brush holder assembly110via a communication link115(e.g., a wireless link). The site monitor120may be configured to receive processed data and/or raw data providing information about the wear state of the brush24and/or the rotating component15. For example, the site monitor120may receive information about a value received from the sensor corresponding to the amount of rotation of the wear state monitor50from its initial position at some temporal occasion after the brush24has been installed on the electrical machine. However, in other examples, the site monitor120may receive information about a value obtained by the sensor and a comparison between the value and one or more predetermined thresholds. In some cases, the communication link115may include a radio frequency (RF) communication link, an audio-based communication link (e.g., an ultrasonic communication link), and/or an optical communication link (e.g., an infrared (IR) communication link, a visible light communication link, etc.). In some cases, the site monitor120may be configured to predict or determine an estimated projection of a condition of the brush24into the future.

In some examples, the wear state monitor50may be configured to communicate the wear state information about the brush24to the site monitor120using a predetermined schedule (e.g., once per hour or hourly, once per day or daily, once per week or weekly, twice per week, etc.). In some examples, the wear state monitor50may provide the wear state information about the brush24and/or the rotating component15of the electrical machine to the site monitor120in response to a command received from the site monitor120and/or the remote monitoring device150,160. Additionally, the site monitor120may be programmed to receive wear state information about the brush24at predetermined intervals. In some cases, the predetermined intervals may be fixed at a particular value (e.g., once per hour or hourly, once per day or daily, once per week or weekly, twice per week, etc.) and in other cases, the intervals may change after a particular wear state has been reached. For example, the site monitor120may be configured to receive wear state information from the wear state monitor50at a first time interval, such as once per day, until one or more brushes24and/or the rotating component15reach a wear state approaching the replacement wear state. At that point, the wear state monitor50may sample the wear state information from the brush24at a second shorter time interval, such as hourly. Thus, the wear state information from the wear state monitor50may be communicated to the site monitor120at first frequency until the brush24reaches a first wear state, and thereafter, the wear state information may be communicated to the site monitor120at a second frequency greater than the first frequency.

The site monitor120may output an indication of the condition and/or projected condition of the brush24. In some cases, the indication may be configured to alert an operator, technician and/or other personnel that the brush24and/or the rotating component15are sufficiently worn and/or needs to be replaced, the brush24and/or the rotating component15are damaged, failure has occurred or is imminent, or other maintenance or inspection may need to be performed. In some embodiments, the indication may be used for scheduling maintenance or inspection, sending personnel to perform maintenance or inspection, ordering and/or scheduling distribution/delivery of a replacement brush or other part, routing maintenance personnel and/or product delivery to a specified location, or arranging for other notification and/or scheduling tasks be performed.

The brush monitoring system100may also be used to identify and/or notify other key maintenance, failure of the brush holder assembly110and/or other anomalous conditions. For example, incidents of excess heating, arcing or excess vibration, which may indicate a need to perform maintenance and/or disrupt operation of the electrical equipment, may be identified and/or assessed by one or more components of the brush monitoring system100. The wear state monitor50, the site monitor120and/or the remote monitoring device150,160may carry out an appropriate response to respond to an identified anomalous condition in an attempt to rectify the anomalous condition. In some cases, an operator may carry out an appropriate response to respond to an anomalous condition identified with the brush monitoring system100in an attempt to rectify the anomalous condition.

In some cases, the site monitor120may be communicatively coupled by a wireless link125and/or wired link127to a network130. The site monitor120may be capable of communicating information about the wear state of one or more brushes24to a remote monitoring device150,160at a remote monitoring site140via the network130and one or more wired137and/or wireless135communication links. The wired link127,137and/or wireless link125,135communication links may be configured to operate using one or more standardized communication protocols (e.g., Ethernet, Ethernet/IP, BACnet, Modbus, LonWorks, etc.), or proprietary communication protocols. Examples of a remote monitoring system are described in U.S. Pat. No. 7,705,744, entitled “MONITORING SYSTEMS AND METHODS FOR MONITORING THE CONDITION OF ONE OR MORE COMPONENTS OF AN ELECTRICAL DEVICE”, U.S. Pat. No. 8,618,943, entitled “BRUSH HOLDER ASSEMBLY MONITORING APPARATUS, ASSEMBLY, SYSTEM AND METHOD”, and U.S. Pat. No. 9,252,643, entitled “SYSTEM AND METHOD FOR MONITORING THE STATUS OF ONE OR MORE COMPONENTS OF AN ELECTRICAL MACHINE”, which are herein incorporated by reference in their entirety. The remote monitoring site140may include one or more remote monitors, such as a personal computer160, a workstation, a laptop, a tablet150, a smart phone or the like, for collecting data and/or analyzing data received from one or more user sites.

The remote monitoring devices and/or site monitor120may be integrated into a maintenance program for a brush holder assembly110, such that the site monitor120may be configured to monitor at least a condition of one or more components of the brush holder assembly110. To do so, the remote monitors and/or the site monitor120may be configured to identify each brush holder assembly110on a particular machine or at a particular site and/or store an installation date and any servicing dates for each brush holder assembly110and/or components thereof, such as the installation date of a brush24in the brush holder assembly110. In some examples, the wear state monitor50(or other sensor of the brush holder assembly110) may output a signal to the site monitor120indicating that a brush24or other component of the electrical machine has been removed and/or replaced, and/or an indication that a new brush24has been installed. Component replacement information may be collected and monitored by the wear state monitor50, one or more sensors of the brush assembly110and/or the site monitor120.

In some cases, one or more parameters received from the wear state monitor50associated with a brush holder assembly110may be monitored over time to determine trending information about a brush24and/or a rotating component15of the electrical machine. For example, the site monitor120and/or the remote monitors may determine trend information, that may include an average lifetime for a brush24installed in a particular brush holder assembly110and/or for a particular installation position on an electrical machine. The site monitor120and/or the remote monitors may be configured to store information about the position of a brush24when the brush24and/or brush holder assembly110is first installed on an electrical machine. By monitoring the final position and/or replacement date of a brush24along with the initial position and/or installation date each time a brush24is replaced and a new brush24is installed in the brush holder assembly110, information may be gathered about a wear state of the rotating component15. For example, a slip ring, or other rotating component of the electrical machine, may have an initial outer diameter measurement. Over time, with wear including normal wear and/or due to environmental conditions (e.g., humidity, temperature, contaminants including abrasives, etc.) a wear state associated with the thickness and/or outer diameter of the rotating component15may be measured and/or predicted. In some cases, preventative measures to improve the lifetime of the brush24and/or the rotating component15may be obtained by analysis of the information received from the one or more wear state monitors50. For example, a user may be advised to adjust one or more environmental conditions for a space near the electrical machine, such as a temperature, a humidity level and/or a contaminant level.

FIG. 2illustrates the wear state monitor50, spring29and spacer30shown inFIG. 1, positioned above an upper surface of a carbon brush24.FIG. 3illustrates an exploded perspective view of the wear state monitor50, spring29and spacer30as described above inFIG. 2. For clarity,FIG. 3illustrates the wear state monitor50, spring29and spacer30after having been rotated 180 degrees as compared with their orientation depicted inFIG. 1andFIG. 2.

As illustrated inFIG. 2in some examples the wear state monitor50and spring29may be nested within the spacer30, such as within a concave cradle of the spacer30. The spacer30may be positioned between the coiled portion of the spring29and the upper or first end surface34of the carbon brush24. In some instances, the spacer30may be attached to the first end surface34of the brush24such that the spacer30moves with the brush24.

For example, as shown inFIG. 3andFIG. 5, the spacer30may include one or more projections38extending from a bottom surface of the spacer30which are designed to engage one or more cavities (e.g., bores)39extending into the brush24from the first end surface34(shown inFIG. 1andFIG. 4A) of the brush24. As illustrated by the dashed lines inFIG. 5, each of the projections38may extend into a corresponding cavity39located within the first end surface34of the brush24. It can be appreciated that engagement of each of the projections38within their respective cavity39may function to secure the spacer30to the brush24in a fixed relationship.

Further, each of the cavities39may be spaced away from one or more of the lead wires62. For example, each of the lead wires62may extend into the brush24from the upper surface34of the carbon brush24at an insertion point along the first end surface34of the brush24. For instance, the ends of the lead wires62may be fixed within bore holes of the brush24. As shown inFIG. 3andFIG. 5, the cavities39may be spaced away (along the upper surface34of the brush24) from the insertion locations of the lead wires62. Thus, the cavities39are distinct from and not intended for receiving ends of the lead wires62therein.FIG. 4Ais a perspective view further illustrating the position and arrangement of the cavities39extending into the brush24, whileFIGS. 4B-4Gillustrate additional views of the brush24.

Further, it can be appreciated that the projections38shown inFIG. 3andFIG. 5may permit the spacer30to be releasably attached to the brush24. In other words, inserting the projections38into the cavities39may attach the spacer30to the brush24with the bottom surface of the spacer30juxtaposed with the upper surface34of the brush24. However, as discussed above, the spacer30(including each of the projections38) may be removed from the brush24after being attached thereto. In other words, the projections38may be designed to be inserted into (e.g., slide into) or removed from (e.g., slide out of) each of their respective cavities39through manual manipulation of the spacer30relative to the brush24without damaging either the spacer30or the brush24, and/or without breaking an adhesive bond or other interface therebetween. In some instances, the projections38may frictionally engage the sidewall of the cavities39when inserted therein, but be readily removed therefrom with a manual extraction force applied to the spacer30without damaging either the spacer30or the brush24.

Additionally,FIG. 3andFIG. 5illustrate each of the projections38may include a particular shape which may be designed to mate with the shape of each of the cavities39. For example, both the projections38and the cavities39may include a geometric cross-sectional shape (e.g., square, pentagon, hexagon, etc.) which allows each of the projections38to fit snugly within its mating cavity39.

FIG. 6andFIG. 7illustrate front and perspective views, respectively, of another example spacer130and brush124(including lead wires162). It can be appreciated that the spacer130, brush124and lead wires162(attached to the first end surface134of the brush124) may be similar in form and function to the spacer30, brush24and lead wires62described above.

Similarly to that described above, the spacer130may include one or more projections138extending from a bottom surface of the spacer130which are designed to engage cavities (e.g., bores)139extending into the brush124from the first end surface134(shown inFIG. 6andFIG. 7) of the brush124. As illustrated by the dashed lines inFIG. 6, each of the projections138may extend into a corresponding cavity139located within the first end surface134of the brush124. It can be appreciated that engagement of each of the projections138within their respective cavity139may function to secure the spacer130to the brush124in a fixed relationship.

Further, each of the cavities139may be spaced away from one or more of the lead wires162. For example, each of the lead wires162may extend into the brush124from the upper surface134of the carbon brush124at an insertion point along the first end surface134of the brush124. For instance, the ends of the lead wires162may be fixed within bore holes of the brush124. As shown inFIG. 6andFIG. 7, the cavities139may be spaced away (along the upper surface134of the brush124) from the insertion locations of the lead wires162. Thus, the cavities139are distinct from and not intended for receiving ends of the lead wires162therein.

Further, it can be appreciated that the projections138shown inFIG. 6andFIG. 7may permit the spacer130to be releasably attached to the brush124. In other words, inserting the projections138into the cavities139may attach the spacer130to the brush124with the bottom surface of the spacer130juxtaposed with the upper surface134of the brush124. However, as discussed above, the spacer130(including each of the projections138) may be removed from the brush124after being attached thereto. In other words, the projections138may be designed to be inserted into (e.g., slide into) or removed from (e.g., slide out of) each of their respective cavities139through manual manipulation of the spacer130relative to the brush124without damaging either the spacer130or the brush124, and/or without breaking an adhesive bond or other interface therebetween. In some instances, the projections138may frictionally engage the sidewall of the cavities139when inserted therein, but be readily removed therefrom with a manual extraction force applied to the spacer130without damaging either the spacer130or the brush124.

Additionally,FIG. 6andFIG. 7illustrate that each of the projections138may include a particular shape which may be designed to mate with the shape of each of the cavities139. For example, each of the projections138shown inFIG. 6andFIG. 7may be generally shaped as a “cone”, e.g., conical or frusta-conical, (whereby the cone-shaped projection138extends away from the bottom surface of the spacer130). As shown inFIG. 6andFIG. 7, each of the projections138may be wider along the bottom surface of the spacer130and taper to a narrower tip. Likewise, each of the cavities139may be generally conical or frusta-conical, with a larger cross-section at the upper surface134, tapering to a smaller cross-section toward the base of the cavities139within the brush124. The generally coned-shaped projections138may allow each of the projections138to fit snugly within its mating cavity139.

FIG. 8andFIG. 9illustrate front and perspective views, respectively, of another example spacer230and brush224(including lead wires262). It can be appreciated that the spacer230, brush224and lead wires262(attached to the first end surface234of the brush224) may be similar in form and function to the spacer30, brush24and lead wires62described above.

Similarly to that described above, the spacer230may include a projection238extending from a bottom surface of the spacer230which is designed to engage a cavity (e.g., channel)239extending into the brush224from the first end surface234(shown inFIG. 8andFIG. 9) of the brush224. As illustrated by the dashed lines inFIG. 8, the projection238may extend into a corresponding cavity239located within the first end surface234of the brush224. It can be appreciated that engagement of the projection238within its respective cavity239may function to secure the spacer230to the brush224in a fixed relationship.

Further, the cavity239may be spaced away from one or more of the lead wires262. For example, each of the lead wires262may extend into the brush224from the upper surface234of the carbon brush224at an insertion point along the first end surface234of the brush224. For instance, the ends of the lead wires262may be fixed within bore holes of the brush224. As shown inFIG. 8andFIG. 9, the cavity239may be spaced away (along the upper surface234of the brush224) from the insertion locations of the lead wires262. Thus, the cavity239is distinct from and not intended for receiving ends of the lead wires262therein.

Further, it can be appreciated that the projection238shown inFIG. 8andFIG. 9may permit the spacer230to be releasably attached to the brush224. In other words, inserting the projection238into the cavity239may attach the spacer230to the brush224with the bottom surface of the spacer230juxtaposed with the upper surface234of the brush224. However, as discussed above, the spacer230(including the projection238) may be removed from the brush224after being attached thereto. In other words, the projection238may be designed to be inserted into (e.g., slide into) or removed from (e.g., slide out of) the cavity239through manual manipulation of the spacer230relative to the brush224without damaging either the spacer230or the brush224, and/or without breaking an adhesive bond or other interface therebetween. In some instances, the projection238may frictionally engage the sidewall of the cavity239when inserted therein, but be readily removed therefrom with a manual extraction force applied to the spacer230without damaging either the spacer230or the brush224.

Additionally,FIG. 8andFIG. 9illustrate that the projection238may include a particular shape which may be designed to mate with the shape of the cavity239. For example, the projection238shown inFIG. 8andFIG. 9may be generally shaped as a “spine” extending both across and away from the bottom surface of the spacer130. As shown inFIG. 8andFIG. 9, the projection238may resemble a rectangular spine extending from the front face of the brush224to the back face of the brush224. The spine238may be designed to fit snugly within its mating channel239.

FIG. 10andFIG. 11illustrate front and perspective views, respectively, of another example spacer330and brush324(including lead wires362). It can be appreciated that the spacer330, brush324and lead wires362(attached to the first end surface334of the brush324) may be similar in form and function to the spacer30, brush24and lead wires62described above.

Similarly to that described above, the spacer330may include a projection338extending from a bottom surface of the spacer330which is designed to engage a cavity339extending into the brush324from the first end surface334(shown inFIG. 10andFIG. 11) of the brush324. As illustrated by the dashed lines inFIG. 10, the projection338may extend into a corresponding cavity339located within the first end surface334of the brush324. It can be appreciated that engagement of the projection338within its respective cavity339may function to secure the spacer330to the brush324in a fixed relationship.

Further, the cavity339may be spaced away from one or more of the lead wires362. For example, each of the lead wires362may extend into the brush324from the upper surface334of the carbon brush324at an insertion point along the first end surface334of the brush324. For instance, the ends of the lead wires362may be fixed within bore holes of the brush324. As shown inFIG. 10andFIG. 11, the cavity339may be spaced away (along the upper surface334of the brush324) from the insertion locations of the lead wires362. Thus, the cavity339is distinct from and not intended for receiving ends of the lead wires362therein.

Further, it can be appreciated that the projection338shown inFIG. 10andFIG. 11may permit the spacer330to be releasably attached to the brush324. In other words, inserting the projection338into the cavity339may attach the spacer330to the brush324with the bottom surface of the spacer330juxtaposed with the upper surface334of the brush324. However, as discussed above, the spacer330(including the projection338) may be removed from the brush324after being attached thereto. In other words, the projection338may be designed to be inserted into (e.g., slide into) or removed from (e.g., slide out of) the cavity339through manual manipulation of the spacer330relative to the brush324without damaging either the spacer330or the brush324, and/or without breaking an adhesive bond or other interface therebetween. In some instances, the projection338may frictionally engage the sidewall of the cavity339when inserted therein, but be readily removed therefrom with a manual extraction force applied to the spacer330without damaging either the spacer330or the brush324.

Additionally,FIG. 10andFIG. 11illustrate that the projection338may include a particular shape which may be designed to mate with the shape of the cavity339. For example, the projection338shown inFIG. 10andFIG. 11may include one or more tapered sides which extend away from the bottom surface of the spacer330. Tapered sides of the projection338may be juxtaposed with the tapered sides of the cavity339when matingly engaged therein. The projection338may be designed to fit snugly within its mating cavity339.

The wear state monitor50may include a first end region40, a second end region42and a medial region43(seeFIG. 3andFIG. 12) extending therebetween. The medial region43may be generally cylindrical, or other such shape designed to facilitate integration into a brush holder assembly110or other mounting location within the brush holder assembly110. In some instances, the medial region43may have a cylindrical circumferential surface. Each of the first end region40and the second end region42may extend radially outward from the circumferential surface of the medial region43, thereby creating a groove or recessed area (further illustrated inFIG. 3andFIG. 12) in which the coiled portion of the spring29may be positioned between the first end region40and the second end region42.

As discussed above, the medial portion43of the wear state monitor50may be designed to be captured within the coiled portion of the spring29. In other words, a portion of the spring29(i.e., the coiled portion) may be coiled (e.g., wrapped) around the medial region43of the wear state monitor50. As shown inFIG. 12, the first end region40and the second end region42may provide a shoulder on opposing sides of the coiled portion of the spring29to ensure that the spring29does not slip out of the groove defined between the first end region40and the second end region42. It can be appreciated that the first end region40and/or the second end region42may be removable, or otherwise configurable, to allow the wear state monitor50to be mounted within a coiled portion of different sized springs. For example, the removable and/or configurable first end region40and/or second end region42, may allow the wear state monitor50to be mounted within a coiled portion of a spring having a first width and a first coil diameter and/or a spring having a second different width and/or a second different coil diameter.

As discussed above, a sensor may be positioned within the wear state monitor50and may measure and collect data representing a current rotational position of the wear state monitor50which can be used to determine the extent (e.g., total angular distance and/or total arc length) of rotation of the wear state monitor50from its initial position whereby the amount of rotation measured by the sensor (positioned within the wear state monitor50) may be equivalent, proportional, or otherwise representative of the linear or longitudinal movement of the brush24(shown inFIG. 1) as it translates (e.g., shortens) within the brush holder22(shown inFIG. 1). In particular, the sensor positioned within the wear state monitor50may be designed to detect the absolute angular position of the sensor relative to a permanent magnet positioned adjacent the sensor. For example,FIG. 2illustrates a magnet14attached to the spacer30, or otherwise incorporated with the spacer30. WhileFIG. 2illustrates the magnet14approximately aligned with the central axis of the wear state monitor50, it is contemplated that the magnet14may be positioned along other portions of the wear state monitor50and/or along other elements of the brush holder assembly110.FIG. 3illustrates that, in some examples, the medial region43of the wear state monitor50may include an engagement feature such as a tab, shoulder or an opening, (not shown inFIG. 2) which may be used to facilitate a connection with or engagement with the second end33of the spring29located on the interior of the coiled portion of the spring29. For example,FIG. 3illustrates a boss (e.g., protrusion)16extending away from the outer surface of the medial region43. The boss14may have a shape configured to mate with a corresponding opening18of the spring29proximate the second end33of the spring29. The opening18may have a shape corresponding to a cross-sectional shape of the boss16. For example, the boss16may have a circular cross-sectional shape designed to mate with a circular shape of the opening18. However, whileFIG. 3illustrates the boss16and the opening18having a circular shape, other shapes are contemplated. For example, the boss16and the opening18may include square, ovular, rectangular, star, triangular, or any other geometric shape. It can be appreciated that engagement of the boss16with the opening18may rotationally fix the wear state monitor50with the coiled portion of the spring29such that rotational movement (e.g., coiling) of the coiled portion of the spring29correspondingly rotates the wear state monitor50an equal amount.

In other embodiments, the outer surface of the medial region43may include a shoulder or raised edge configured to engage the second end33of the spring29when the coiled portion of the spring29is coiled around the medial region43. In some instances, the second end33of the spring29may be trapped underneath the layers of the coiled spring29wound thereover, which may apply a radially inward compressive force on the second end33of the spring29to maintain the second end33of the spring29against the surface of the medial region43, ensuring the second end33of the spring29remains rigidly fixed to the wear state monitor50.

FIG. 3further illustrates that the first end of the spring32may be folded back on itself to form a tab, wherein the tab is designed to be removably coupled to the brush holder and/or the mounting beam26(shown inFIG. 1). In other words, the tab19may be designed to engaged (e.g., be inserted into) a portion of the brush holder and/or the mounting beam26.

As illustrated inFIG. 3, the spacer30may include one or more arcuate surfaces36defining a concave cradle designed to mate with the circumferential profile of the wear state monitor50. In other words, the spacer30may include one or more concave surfaces36having a radius of curvature that substantially matches the radius of curvature of the outer surface of the wear state monitor50. Thus, a portion of the wear state monitor50may be positioned in the concave cradle of the spacer30. The spacer30may be positioned between the coiled portion of the spring29and the upper surface of the brush24to space the coiled portion of the spring29away from the brush24.

Additionally,FIG. 3illustrates that the spacer30may include a projection31designed to engage the second end region42of the wear state monitor50. It can be appreciated that the second end region42may include a recess (not shown) which is designed to mate with the projection31and permit rotational movement of the wear state monitor50about a rotational axis aligned with the central axis of the projection31. The engagement of the projection31within the recess of the second end portion may provide additional securement between the wear state monitor50and the spacer30while permitting rotational movement therebetween. Thus, it can be appreciated the projection31may cooperate with the arcuate surfaces36of the concave cradle to permit the wear state monitor50to rotate (as described above) when engaged with the spacer30.

FIG. 12illustrates an end view of the wear state monitor50including the first end region40, the second end region42and the medial region43extending therebetween. As discussed above,FIG. 12illustrates the outer peripheral surfaces of both the first end region40and the second end region42extending radially outward beyond the cylindrical circumferential surface of the medial region43. As described above, the inner surfaces of each of the first end region40, the second end region42and the circumferential surface of medial region43may define a groove in which the spring29may be positioned, with the inner surfaces of the first and second end regions40,42forming shoulders.

FIG. 13shows a side view of the wear state monitor50and the spring29described above.FIG. 13illustrates that spring29may include an elongate portion extending away from the wear state monitor50whereby the first end32of the spring29extends past the outer circumferential surface of the wear state monitor50. As noted above, the first end32of the spring29(including tab19described above) may be removably coupled to the brush holder and/or the mounting beam26with the elongate portion of the spring29extending along a side surface of the brush24, between the brush24and the mounting beam26. Additionally,FIG. 13illustrates spring29wrapping around the medial region43of the wear state monitor50. For example, the dashed line represents the spring29wrapping around the medial region43of the wear state monitor50, whereby the second end33of the spring29is coupled to or otherwise in contact with the wear state monitor50, such as via the boss16and opening18connection, as described above with respect toFIG. 3.

FIG. 14illustrates an exploded view of the wear state monitor50described above. As illustrated inFIG. 14, the wear state monitor50may include an exterior housing52. The exterior housing52may include an inner cavity54. The cavity54may be configured to contain one or more internal components of the wear state monitor50. The wear state monitor50may also include a housing lid60configured to mate with the exterior housing52. In other words, the lid60may be designed to be rigidly attached to the exterior housing52. In other instances, the exterior housing52may be adhesively bonded or snap fit to the lid60to secure the exterior housing52and the lid60together. Further, the lid60may include an aperture71extending through the entire wall thickness of the lid60.

Additionally, the wear state monitor50may include a button59. In some instances, the button59may be a Viton button. The button59may be utilized to pair the wear state monitor50to another device via a Bluetooth connection, for example. Further, it can be appreciated that a portion of the button59may be designed to project through the aperture71of the lid60, thereby making the button59accessible to depress and pair the wear state monitor50to another device via a Bluetooth connection. When the exterior housing52is engaged with the lid60and the button59, the cavity54created by the combination of the exterior housing52, the lid60and the button59may be sealed to the outside environment.

In other instances the housing52may include a first housing section and a second housing section separable from one another to expose an interior cavity of the wear state monitor50housing the internal components of the wear state monitor50. In some instances, the first housing section and the second housing section may be hingedly connected (e.g., connected in a “clam shell” configuration), or otherwise movable relative to one another. In such cases, when the wear state monitor50is located within the coiled portion of the spring29(e.g., a helical spring), the force provided by the spring29may facilitate a compression connection or snap fit connection for engaging the first housing section with the second housing section of the wear state monitor50. In other instances, the first housing section may be adhesively bonded or snap fit to the second housing section to secure the first and second housing sections together.

FIG. 14further illustrates that the wear state monitor50may further include a power source53(e.g., one or more batteries, capacitors, or both) and a sensor56(it is noted that the sensor56may correspond to the sensor described above with respect toFIG. 1). The power source53may be rechargeable and/or replaceable.

In some instances, the sensor56may be referred to as an angular sensor56and/or a magnetic encoder56. As discussed above, the sensor56may produce a signal corresponding to the rotation (e.g., the absolute angular position) of the wear state monitor50relative to the stationary magnet14described above with respect toFIG. 2. For example, the sensor56may be able to sense a change in the magnetic field created by the magnet14, thus determining a rotational orientation of the wear state monitor50. The signals provided by the sensor56corresponding to the rotational orientation of the wear state monitor50may be compared to determine an angular displacement of the wear state monitor50between two temporal occasions, such as between an angular position of the wear state monitor50when the brush24is installed in the brush holder assembly110and some later time when the brush24has worn. These signals (corresponding to the angular displacement and/or rotational orientation of the wear state monitor50) may be communicated to the site monitor120via a variety of communication methods. In some instances, the sensor56may additionally include an accelerometer configured to sense dynamic vibration of the brush24in the brush holder22. For example, the sensor56, in addition to sensing angular displacement and/or rotational orientation of the wear state monitor50, may sense transient angular displacement of the wear state monitor50corresponding to dynamic vibration of the brush24.

Additionally, in some cases, the power source53and/or sensor56may be located within the cavity54of the wear state monitor50, such that the power source53and/or the sensor56may be integrated with the wear state monitor50. Further, it can be appreciated that when the exterior housing52is engaged with the lid60and the second button member59, both the power source53and the sensor56may be sealed within the cavity54formed by the combination of the exterior housing52, the lid60and the second button member59.

Additionally,FIG. 14illustrates that the wear state monitor50may include a first foam insulation member61aand a second foam insulation member61b. In some instances, each of the first foam insulation member61aand the second foam insulation member61bmay be formed from silicone. Other materials may be utilized to form the first foam insulation member61aand/or the second foam insulation member61b. Further, the first foam insulation member61aand the second foam insulation member61bmay be utilized to insulate the power supply53when positioned within the cavity54. In other words, when positioned inside the cavity54, the power supply53may be disposed between the first foam insulation member61aand the second foam insulation member61b.

The power source53of the wear state monitor50may be used to supply power to one or more components of the wear state monitor50, such as the sensor56, to facilitate the measurement and generation of a value representative of the angular displacement or rotation of the wear state monitor50(which is proportional to the diminution in length of the brush24during use, as described above). In other words, as the wear state monitor50rotates in response to the diminution in length of the brush24as the brush24wears, the sensor56may sense, measure and collect the information (e.g., data) of the amount of rotation or angular displacement of the wear state monitor50, which is proportional to or otherwise correlates to the amount of diminution in length of the brush24. The wear state monitor50rotates about an axis of rotation passing through the center of the wear state monitor50. The axis of rotation is a fixed distance from the second end34of the carbon brush24as the wear state monitor50rotates, and thus the axis of rotation translates with the brush24as the brush24wears and diminishes in length.

For example, in some instances, the sensor56may obtain values corresponding to a first position of the brush24, at a first temporal occasion T0, such as an initial position of the brush24when the brush24has been placed on the electrical device and having approximately no wear. In other words, the sensor56may be used to sense the angular position of the wear state monitor50at the initial temporal occasion T0. The sensor56may obtain values corresponding to a position of the brush24at a later temporal occasion T1after the brush has been worn a first amount. In other words, the sensor56may be used to sense the angular position of the wear state monitor50at the temporal occasion T1. The sensor56may obtain additional values corresponding to a further positions of the brush24at later temporal occasions T2, T3, T4, etc. after the brush has been worn an additional amount. In other words, the sensor56may be used to sense the angular position of the wear state monitor50at the further temporal occasions T2, T3, T4, etc. The angular displacement of the wear state monitor50between each temporal occasion may be used to determine the diminution in length of the brush24, and thus the current wear state of the brush24and/or project when the brush24will diminish in length to a threshold amount at a future time. In some instances the threshold amount may correspond to a brush length approximating when the brush24has a predetermined amount of wear (e.g., approaching the replacement threshold, maximum allowable wear, etc.).

Additionally, in some cases, the sensor56may be configured to sense a first threshold value corresponding to a first wear state of the brush24and a second threshold value different from the first threshold value corresponding to a second wear state of the brush24. For example, the first threshold value may include the total rotation amount or angular displacement of the wear state monitor50indicative of a wear state where the brush24should be replaced within a predetermined time period (e.g., within a week). The second threshold value may correspond to a total rotation amount or angular displacement of the wear state monitor50indicative of a wear state requiring the brush24to be replaced as soon as possible.

FIGS. 15 and 16illustrate side views of the brush holder assembly110shown inFIG. 1, at different temporal occasions representing different identifiable wear states of the brush24. For simplicity purposes, the spacer30(shown inFIG. 1) has been removed fromFIGS. 15 and 16. Additionally,FIGS. 15 and 16illustrate the brush holder assembly110including the brush holder22secured to the mounting beam26, whereby the mounting beam26is configured to be removably mounted to the mounting block70. Further,FIGS. 15 and 16show the mounting beam26including the upper beam member27and the lower beam member28pivotally coupled to one another in the engaged position, as described above with respective toFIG. 1.FIG. 15andFIG. 16further illustrate the brush holder assembly110including a handle21and the conductive wires62attached to both the brush24and extending therefrom.

As discussed above and illustrated inFIGS. 15 and 16, an end region of the spring29may be coiled around a portion (e.g., the medial region) of the wear state monitor50while the elongate portion of the spring29extends along a side surface of the brush24with the first end32of the spring29coupled to the mounting beam26. Further, while not visible inFIGS. 15 and 16, a sensor and/or power supply may be positioned within an interior space (e.g., a cavity) within the wear state monitor50(as described above).

FIG. 15illustrates a first configuration (e.g., an initial wear state) of the brush24at an initial temporal occasion T0, such as when the brush24of the brush holder assembly110is first installed on an electrical machine.FIG. 15illustrates the brush24positioned within the brush holder22(as described above with respect toFIG. 1), with the lower surface of the brush24engaged with the conductive surface12of the rotating component15. Additionally,FIG. 15shows that the first end surface34of the brush24is positioned a distance X1from the end of the brush holder22nearest the handle21at an initial position at the initial temporal occasion T0. It can be appreciated that when the brush holder assembly110is in an engaged position, the spring29may apply a force to the first end surface34of the brush24to engage the brush24with the conductive surface12of the rotating component15.

For illustrative purposes,FIG. 15includes a “rotation marker”64placed on the wear state monitor50. For simplicity, the rotation marker64has been placed on the wear state monitor50at approximately the “twelve 'o clock” position, but could be placed at any desired location. The rotation marker64need not be a visual marker, although it is possible to include a visual marker. The rotation marker64may be representative of a positional signal provided by the sensor56of a rotational orientation of the wear state monitor50.

FIG. 16illustrates a second configuration (e.g., a second wear state) of the brush24at a later temporal occasion T1, such as after the brush24has engaged the conductive surface12of the rotating component15over a period of time and diminished in length. As described above, the spring29may continue to exert a force on the first end surface34of the brush24as the brush24wears away against the conductive surface12of the rotating component15. For example,FIG. 16illustrates the first end surface34of the brush24positioned a distance X2from end of the brush holder22nearest the handle. It can be appreciated that the difference between distance “X2” and distance “X1” shown inFIG. 15, represents the amount of diminution in length of the brush24(i.e., how much the brush24has shortened in length).

Additionally, as described above, as the brush24translates within the brush holder22, the wear state monitor50may rotate in proportion to the length of shortening of the brush24. The rotation or angular displacement θ of the wear state monitor50between the initial rotational position of the wear state monitor50at T1and the rotational position of the wear state monitor50at T1is illustrated inFIG. 16. Additionally,FIG. 16shows the rotation position marker64in a second position, further representing the rotation or angular displacement of the wear state monitor50. It is noted that the rotational axis of the wear state monitor50remains at a fixed distance from the upper surface of the brush24throughout the wear of the brush24.

As described above, as the wear state monitor50rotates in response to the shortening of the brush24(e.g., the wearing of the second end surface35of the brush24), the sensor56may measure and collect information relating to the rotation or angular displacement of the wear state monitor50. Further, this information relating to the rotation or angular displacement of the wear state monitor50may be analyzed to determine an amount of diminution in length of the brush24, a current wear state of the brush24, a wear rate of the brush24, and/or predict a future wear state of the brush24at a future time. Such information and/or data regarding the state of the brush24may be communicated to the site monitoring device120and/or a remote monitoring device140. The remote monitoring device140may be located at the same and/or at a different geographical location from the geographical location of the electrical machine and the site monitoring device120.

In some cases, the wear state monitor50, the site monitor120and/or the remote monitoring device140may include a processor capable of processing instructions for predicting a life expectancy of the brush24and/or the rotating component15of the electrical machine. In some cases, the processor may be capable of processing instructions for identifying the wear state of the carbon brush and/or identifying the wear state of the rotating electrical component (e.g., a slip ring, a commutator, etc.) of the electrical device.