Embodiments relate to a brush holder assembly and related methods.
Some rotary electromechanical devices, such as commutators or slip rings, and associated carbon brushes and holders are used in an industrial context, such as power generation. A spring may maintain constant contact between the brush and the rotary electromechanical device. Eventually, wear on the brush can hinder constant contact or secure positioning of the brush in the brush holder such that the brush must be replaced.
A brush holder holds a brush in place and may be configured for ease of replacing worn brushes. In some known brush holders, the spring applies force to the brush, while a movable brush catch selectively prevents downward movement of the brush. The brush catch in these known brush holders moves into contact with the brush to engage a bottom surface or a side surface of the brush, for example to apply a force to the bottom or side surface of the brush. However, the brush catch may not reliably secure the brush within the brush holder and instead may allow unintended movement of the brush within the brush holder. Moreover, the brush catch can potentially damage the brush, and the brush catch itself may be susceptible to damage.
Embodiments relate to assemblies that facilitate mounting and replacement of brushes that interact with a rotary electromechanical device. In one embodiment, the assembly can include a brush from which a shunt extends, and the brush can be received by a brush box of a brush holder. The shunt can have a first end and a second end that define a length of the shunt, the first end of the shunt can be connected to the brush, and the second end of the shunt can connect to the brush holder. The brush holder can include a back plate fixed to the brush box. A lever is connects to the back plate, and the lever may reversibly and selectively rotate between a first position and a second position; the lever can have a distal portion, and the second position of the lever secures a portion of the shunt between the distal portion of the lever and another component of the brush holder. The secured portion of the shunt can restrict downward movement of the brush in the brush box, while a spring pushes downward on the brush in the brush in the brush box, to thereby fixedly position the brush in the brush box.
A technical effect of one or more embodiments disclosed herein is to provide an improved brush holder assembly. Another technical effect of one or more embodiments disclosed herein is to enhance ease of brush mounting and replacement. Still another technical effect of one or more embodiments disclosed herein is to substantially fixedly position a brush in a brush holder when a handle is attached to the brush holder. The positioning may be done without applying force to a bottom surface or a side surface of the brush. In one embodiment, positioning may be done without any component of the brush holder abutting a bottom surface of the brush, and without pushing the brush against an inner surface of the brush box.
Another technical effect of one or more embodiments disclosed herein is an actuated lever that engages a brush shunt, instead of engaging the brush itself, to substantially fixedly position the brush in a brush holder when a handle is attached to the brush holder. One or more embodiments disclosed herein is a spring which applies force to a top surface of the brush and cooperates with a lever actuated by attachment of a handle to the brush holder to thereby substantially fixedly position the brush in the brush holder. An embodiment may automatically and reliably restrict and/or prevent vertical movement of a brush in a brush holder when a handle is attached to the brush holder and automatically and reliably allow vertical movement of the brush in the brush holder when the handle is removed from the brush holder.
Additional features are described herein and will be apparent from the following Detailed Description and the Figures.
Embodiments relate to a brush holder assembly and related methods. An embodiment of a brush holder assembly 10 provided by the present disclosure is generally illustrated in
Referring again to
The brush box may receive at least a portion of the brush and at least partially support and restrain movement of the brush during operation. One or more side surfaces of the brush can abut a corresponding inner surface of the brush box. In an embodiment, the assembly does not have any component that applies a force to any side surface of the brush and does not have any component that abuts the bottom surface of the brush (herein, “side surfaces” of the brush do not include the top surface of the brush and do not include the bottom surface of the brush).
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The brush holder includes a lever 26 that may selectively restrain movement of the brush in the brush box during installation of the brush or removal of the brush from the surface of the rotary device, as discussed in greater detail later herein. In one embodiment shown in
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The lever in the second position may press the shunt against a pad 23 on the back plate to thereby fixedly position the brush in the brush box, for example to fixedly position the brush in the brush box by cooperation with downward force from the spring on the brush. For example, the brush can be fixedly positioned in the brush box by downward force from the spring and restraint on downward movement by the shunt when the shunt is secured by the lever in the second position.
One or more side surfaces of the brush can abut a corresponding inner surface of the brush box. In one embodiment, three or four side surfaces of the brush abut a corresponding inner surface of the brush box (“side surfaces” of the brush, as used herein, do not include the top surface of the brush and do not include the bottom surface of the brush). In one embodiment, the fixed position of the brush may be maintained by the assembly without any component of the assembly abutting the bottom surface of the brush and without pushing any of the side surfaces of the brush.
In one embodiment, the pad has or defines a plurality of grooves or ridges formed in the back plate and can grip the portion of the shunt abutted by the lever when the portion of the shunt abutted by the lever is pressed against the pad by the lever. In one embodiment, the pad has a plurality of protrusions that can grip a portion of the shunt. In one embodiment, the pad can be integral with the back plate, for example as the same piece of material as the back plate. In other embodiments, at least a portion of the pad can be a different material than the back plate. Dissimilar materials can be selected to provide selective electrical conductivity (e.g., metal or metal filled polymer) or electrical resistance (e.g., alumina or non-filled polymer). Dissimilar materials can be selected to provide relatively extra grip or traction. Dissimilar material may be selected to provide additional wear resistance in spots that may be exposed to higher levels of contract or wear, or corrosion resistance.
In the embodiment illustrated in the figures, the first position of the lever can be substantially perpendicular to the back plate, and/or the second position of the lever can be positioned at an angle relative to the back plate that is not substantially perpendicular relative to the back plate, for example at an angle of approximately forty-five degrees relative to the pad. The angle of the lever in the second position can be selected or determined such that the angle is based on the thickness of the shunt to ensure that the second position of the lever secures the shunt against the pad. In one embodiment, the pad can be a component of the assembly against which the shunt is secured by the lever in the second position.
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The distal portion 26b of the lever may include a horizontal bar substantially perpendicular to each of the one or more legs 26a. In one embodiment, a horizontal bar connects to an end of each of the one or more legs 26 that is positioned distal from the back plate. When the brush is received by the brush box, a portion of the shunt between the first and second ends of the shunt may abut the distal portion of the lever. In an embodiment, the distal portion 26b is rotatably connected to the one or more legs such that the distal portion 26b rolls along the shunt as the lever moves between the first position of the lever and the second position of the lever.
A suitable shunt may include first and second braided copper cables. The distal portion 26b of the lever may include a horizontal bar comprising first and second grooves, the first groove of the horizontal bar can receive at least a portion of the first braided copper cable, and the second groove of the horizontal bar can receive at least a portion of the second braided copper cable.
In an embodiment, the distance between the distal portion of the lever and the pad is greater in the first position of the lever than the second position of the lever. A portion of the shunt abutted by the lever rests on at least the distal portion of the lever when the lever is in the first position, and the portion of the shunt abutted by the lever is fixedly positioned between the distal portion and the pad when the lever is in the second position. The distance of the distal portion from the pad when the lever is in the second position can be substantially equal to the thickness of the shunt (e.g., slightly less than the thickness of the shunt but still substantially equal to the thickness of the shunt) to ensure that the second position of the lever secures the shunt against the pad.
For example, as shown in
The lever may be actuated by one or more pins 27 to retain the brush in the brush box. For example, the one or more pins can extend through an upper exterior surface 34 of the back plate, and/or the one or more pins can be positioned at least partially in the back plate.
The one or more pins can be pushed downward in the back plate, for example by the handle moving into abutment with the upper exterior surface of the back plate, to thereby push the lever from the first position to the second position. Movement of the lever from the first position to the second position can move a portion of the shunt into abutment with the pad.
The one or more pins can subsequently move upward, for example by the handle being removed from abutment with the upper exterior surface of the back plate and/or the one or more pins being spring-biased upward, to thereby return the lever to the first position from the second position. Movement of the lever back to the first position from the second position can release the portion of the shunt, which was previously secured against the pad, from abutment with the pad.
For example, the lever can include one or more proximal portions 26c opposite from the distal portion 26b, and the one or more legs 26a can connect to and/or define the one or more proximal portions 26c. The one or more legs 26a can have a pivot 26d between the distal portion 26b and the one or more proximal portions 26c. In an embodiment, each of the one or more proximal portions 26c is at least partially positioned in a corresponding groove on a side of the back plate, and each of the one or more proximal portions 26c may be aligned (e.g., at least vertically aligned) with a counterpart of the one or more pins.
The one or more pins can be moved downward in the back plate, for example by the handle moving into abutment with the upper exterior surface of the back plate such that the handle directly or indirectly pushes the one or more pins. Movement of the one or more pins downward in the back plate can cause the one or more pins to directly or indirectly push the one or more proximal portions 26c of the one or more legs 26a downward. As a result, pivoting of the one or more legs 26a on the pivot 26d can push the distal portion 26b upward, such that the lever moves from the first position to the second position.
The one or more pins can be moved upward in the back plate. The pins may move to their original position prior to connection of the handle to the back plate. For example, the pins may be moved by one or more of (i) the handle being removed from abutment with the upper exterior surface of the back plate such that the handle is removed from abutment with the one or more pins (or an intermediate component), (ii) the one or more pins being spring-biased upward, or (iii) the one or more proximal portions 26c being spring-biased upward. Movement of the one or more pins upward in the back plate can cause the one or more proximal portions 26c of the legs 26a to move upward. As a result, pivoting of the legs 26a on the pivot 26d can push the distal portion 26b downward, such that the lever moves from the second position to the first position.
The brush may be fixedly positioned in the brush box by downward force from the spring and restraint on downward movement by the shunt when the shunt is secured against the pad by the lever in the second position. The spring may be a ribbon spring or another biasing member and may be attached to at least one of the brush box or the back plate. As shown in the figures, the spring may attach to the front of the brush box, for example by rivet holes 45 in the front of the brush box. When the brush is positioned within the brush box, the spring contacts a top surface of the brush to nominally bias the brush toward the surface of the rotary device. As the brush experiences wear, the spring can roll upon itself to continuously bias the brush toward the surface of the rotary device.
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In one embodiment, the central bore has a length (the distance from the opening in the connecting member to the opening in the upper interior surface of the back plate) that is less than the length of the post. The post may completely extend through the central bore as shown in
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The stem may be fixedly connected to the shell so that rotation of the stem rotates the shell. For example, one or more threads 61 on the stem may mate with complementary threads 63 on the shell, although any connection known to one of ordinary skill may be used. The stem may include insulation 65 that may enable the handle to be attached, used and removed while the rotary device is energized or rotating. In one embodiment, the shell maintains the one or more pins on their downward position during rotation of the handle, to thereby maintain the lever in the second position which secures the shunt against the pad.
The handle can include a cavity 66 within the shell and can further include a core 70 moveably positioned in the cavity. The shell, including shell teeth 78 at the bottom of the shell, and the core enable the handle to receive and connect to the connecting member which is part of the back plate of the brush holder as discussed in detail hereafter. Preferably, the inside diameter of the cavity is substantially the same as the outside diameter of the core. The height of the cavity is such as to allow the core to travel within the cavity to facilitate selective engagement of the core with the locking flange.
The shell of the handle can include a stop 79 extending downward from the shell. The stop can abut the rear exterior surface of the back plate of the brush holder when the handle is connected to the back plate. The core may include a recess 80 on the bottom surface of the core, and the recess may be a vertical cylindrical recess having a central axis along the vertical axis of the core and/or the vertical axis of the handle. The recess has a radius and/or a circumference that is substantially the same as the radius and/or the circumference of the post, respectively. The core may include core teeth 74 that extend downward from the bottom surface of the core on opposite sides of the recess. In one embodiment, the distance between the core teeth is substantially the same as the width of the locking flange.
The shell teeth can extend inward from opposite inner sides of the shell in a direction that is substantially horizontal. The shell teeth may not vertically overlap the core teeth. In one embodiment, the inner diameters and widths of the shell teeth are substantially the same as the outer dimensions of the locking flange.
A compression spring 72 may be positioned at least partially within the cavity and may extend from the stem to abut the top surface of the core. Force upon the bottom of the core may slide the core upward within the cavity, but the compression spring nominally biases the core downward in the cavity against the top of the shell teeth in a resting state. In an embodiment, the compression spring nominally biases the core downward such that the shell teeth are in substantially the same horizontal plane as the core teeth. The core can optionally include a pin 76 that extends outward horizontally from the core into a slot 81 in the shell.
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The rocker assembly can include a rocker arm 92, a pin 94 that connects the rocker arm to the post, and a rocker spring 96 positioned at least partially between the post and the rocker arm. The rocker arm can rotate on the pin, and the rocker spring can nominally bias the bottom end of the rocker arm outward such that the bottom end of the rocker arm extends outward from the slot 89 in a resting state.
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After the shell of the handle is positioned as needed for the shell to receive the connecting member, the handle may be moved onto the upper exterior surface of the back plate, thereby sliding the shell teeth past the locking flange as the connecting member is received by the shell. Sliding the shell teeth past the locking flange positions the locking flange in a horizontal plane that is above the horizontal plane of the shell teeth. Sliding the shell teeth past the locking flange can slide the boss through the lateral notch such that the locking flange and the boss 55 move into a horizontal plane that is above the horizontal plane of the shell teeth.
Receipt of the connecting member by the shell may insert the post into the recess 80, thereby pushing the core upward due to force from the post against the biasing of the compression spring 72. For example, the post can push the core upward such that the core moves out of contact with the shell teeth. In one embodiment, the core may be positioned such that the core teeth 74 are in a horizontal plane that is above the horizontal plane of the locking flange which is above the horizontal plane of the shell teeth.
In one embodiment, the connection of the handle to the back plate positions the shell in abutment with the upper exterior surface of the back plate. Positioning the shell in abutment with the upper exterior surface of the back plate includes the shell pushing the one or more pins downward in the back plate to thereby have the one or more pins push the proximal portions 26c of the one or more legs 26a of the lever downward, such that the lever moves from the first position to the second position to secure the shunt against the pad.
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In one embodiment, the shell continues to push the one or more pins downward in the back plate during rotation of the handle, such that the one or more pins continue to push the proximal portions 26c of the one or more legs 26a of the lever downward, such that the lever is maintained in the second position to continuously secure the shunt against the pad.
This rotation of the handle also vertically aligns the boss with a complementary groove 86 in one of the core teeth. In an embodiment, the boss and the complementary groove have substantially the same shape and/or have substantially the same size. With the core pushed upward by the locking flange, the complementary groove 86 is positioned in the same horizontal plane as the core teeth, which is above the horizontal plane in which the locking flange and the boss are positioned. In one embodiment, the boss and groove are rectangular, and complimentary to each other. In other embodiments, the boss and groove are rounded or ovoid, and with the complimentary shape.
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In one embodiment, the shell continues to push the one or more pins downward in the back plate during removal of the brush holder, which is connected to the handle, from the support, such that the one or more pins continue to push the proximal portions 26c of the one or more legs 26a of the lever downward, such that the lever is maintained in the second position to continuously secure the shunt against the pad.
Removal of the brush holder, which is connected to the handle, from the support removes the post from the recess 80 of the core to allow the core to drop down on the locking flange. The core teeth move into the same horizontal plane as the locking flange, with the inner sides of the core teeth abutting the sides of the locking flange and the groove receiving the boss. This action effectively locks the handle to the brush holder because the compression spring biases the core down onto the connecting member with the boss within the groove and the core teeth preventing rotation of the locking flange. In an embodiment, locking of the handle to the brush holder prevents the handle from being disconnected from the brush holder except by fully seating the brush holder on a support, discussed in further detail hereafter.
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This action moves the groove upward, away from the boss, and moves the core teeth upward, away from the locking flange. Thus the handle can then be rotated (step (3) of the second method) from the locked position in which the shell teeth are underneath the locking flange to the unlocked position shown in
This action frees the rocker assembly from a restrictive circumference of the recess, allowing the rocker spring to extend and bias the rocker arm outward relative to the post. Extension of the rocker arm outward from the post provides a visual indication that the brush holder is fully seated on the support.
The brush holder assembly can be used in a process for replacing a brush used with a rotating device and/or a process for replacing a brush holder used with a rotating device. One or both of the first and second methods disclosed above can be implemented in a process for replacing a brush used with a rotating device and/or a process for replacing a brush holder used with a rotating device.
Accordingly, the disclosure provides a method of replacing a brush on an operating apparatus, the method includes (a) positioning a handle on a brush holder, in which the brush is at least partially positioned, while the brush holder is connected to a support comprising a post, wherein the positioning of the handle on the brush holder/support assembly inserts the recess in a core moveably positioned in a cavity of the handle into the post and furthermore pushes one or more pins downward in the brush holder to actuate a lever that secures a shunt of the brush against another component of the brush holder; (b) rotating the handle relative to the brush holder in a first direction of handle rotation that is clockwise or counter-clockwise to connect the handle to the brush holder and maintain the lever securing the shunt against the other component of the brush holder; (c) removing the brush holder from the support by pulling the handle with the handle attached to the brush holder, while maintaining the lever securing the shunt against the other component of the brush holder; (d) removing the brush, during which the handle may or may not be attached to the brush holder; (e) positioning a replacement brush at least partially in the brush holder, during which the handle may or may not be attached to the brush holder; (f) using the handle to position the brush holder with the handle attached and with the replacement brush on a support; (g) then rotating the handle in a second direction that is opposite to the first direction to release the handle from the brush holder; (h) then removing the handle from the brush holder, which moves the lever to release the shunt of the brush from being secured between the lever and the other component of the brush.
Step (a) can include one or more of (i) receiving a connecting member located on the brush holder in a shell that forms the base of the handle; (ii) positioning inward-directed horizontal teeth of the handle on opposite sides of a locking flange on the brush holder, (iii) aligning a boss located on a connecting member with a notch in the handle, or (iv) the recess depressing a rocker arm located on the post.
Step (b) can include one or more of (i) rotating the handle approximately ninety degrees relative to the brush holder, (ii) limiting the handle rotation to about ninety degrees, (iii) rotating inward-directed horizontal teeth of the handle from a position offset relative to a locking flange on the brush holder to a position underneath the locking flange in a vertical direction, (iv) rotating downward-directed teeth in the handle from a position vertically overlapping a locking flange located on the brush holder to a position offset relative to the locking flange, or (v) vertically aligning a boss on a connecting member located on the brush holder with a complementary groove provided by the core.
Step (c) can include one or more of (i) removing the brush holder from the post, (ii) removing the recess in the core from the post, (iii) aligning a complementary groove provided by the core to pass by a boss located on a connecting member, (iv) sliding the core downward in the cavity, or (iv) releasing a rocker arm on the post as the core recess is removed. Step (e) can include positioning a portion of the shunt of the brush between the distal portion of the lever and the pad of the back plate. Step (f) can include one or more of (i) sliding the brush holder onto the post, (ii) receiving the post in the recess of the core, or (iii) the recess depressing a rocker arm located on the post. Step (g) can include one or more of (i) rotating the handle approximately ninety degrees relative to the brush holder, (ii) rotating inward-directed horizontal teeth of the handle from a position underneath the locking flange on the brush holder in a vertical direction to a position offset relative to a locking flange located on the brush holder, (iii) rotating downward-directed teeth in the handle from a position offset relative to the locking flange to a position vertically overlapping a locking flange on the brush holder, (iv) limiting the handle rotation to about ninety degrees, or (v) moving a connecting member on the brush holder out of vertical alignment with a complementary groove provided by the core.
Step (h) can include one or more of (i) removing the post from the recess in the core, (ii) sliding the core downward in the cavity, (iv) the recess releasing a rocker arm on the post, or (v) interlocking the handle so the handle is not removable until the brush holder is completely seated on the support.
The disclosure provides a method of replacing a brush holder, the method comprising (a) positioning a handle on the brush holder while the brush holder is connected to a support comprising a post, wherein the positioning of the handle on the brush holder inserts the post into a recess in a core moveably positioned in a cavity of the handle and furthermore pushes one or more pins downward in the brush holder to actuate a lever that secures a shunt of the brush against another component of the brush holder; (b) rotating the handle relative to the brush holder in a first direction that is clockwise or counter-clockwise to connect the handle to the brush holder and maintain the lever securing the shunt against the other component of the brush holder; (c) removing the brush holder from the support by pulling the handle while the handle is attached to the brush holder, while maintaining the lever securing the shunt against the other component of the brush holder; (d) rotating the handle relative to the brush holder while pulling a trigger on the handle that moves the core upward in the cavity; (e) removing the handle from the brush holder, which moves the lever to release the shunt of the brush from being secured between the lever and the other component of the brush; (f) positioning the handle on a replacement brush holder; (g) rotating the handle relative to the replacement brush holder to connect the handle to the replacement brush holder; (h) using the handle to position the replacement brush holder on the support; (i) then rotating the handle in a second direction that is opposite to the first direction; and (j) then removing the handle from the replacement brush holder.
As used herein, “upward” means in a direction substantially toward the top of
As used in this disclosure and the appended claims, the singular forms “a,” “an” and “the” include plural referents unless the context clearly dictates otherwise. The words “comprise,” “comprises” and “comprising” are to be interpreted inclusively rather than exclusively. Likewise, the terms “include,” “including” and “or” should all be construed to be inclusive, unless such a construction is clearly prohibited from the context. However, the devices and assemblies disclosed herein may lack any element that is not specifically disclosed. Thus, a disclosure of an embodiment using the term “comprising” includes a disclosure of embodiments “consisting essentially of” and “consisting of” the components identified. Any embodiment disclosed herein can be combined with any other embodiment disclosed herein unless explicitly indicated otherwise. “Substantially the same” and “approximately” with respect to numerical values means within 10%, within 5%, more within 1%, or within 0.1%. For example, “substantially perpendicular” means at an angle between 81 degrees and 99 degrees (inclusive), between 85.5 degrees and 94.5 degrees (inclusive), or between 89 degrees and 91 degrees (inclusive). Furthermore, all numerical ranges herein should be understood to include all integers, whole or fractions, within the range. Moreover, these numerical ranges should be construed as providing support for a claim directed to any number or subset of numbers in that range. For example, a disclosure of from 1 to 10 should be construed as supporting a range of from 1 to 8, from 3 to 7, from 1 to 9, from 3.6 to 4.6, from 3.5 to 9.9, and so forth. A “fixed position” means that the referenced component can move at most 10.0 millimeters relative to the initial position, 5.0 millimeters relative to the initial position, or at most 2.0 millimeters relative to the initial position.
Changes and modifications to the embodiments described herein will be apparent to those of ordinary skill in the art. Such changes and modifications can be made without departing from the scope of the subject matter and the appended claims. Such changes and modifications are covered by the appended claims.
The present application claims priority to U.S. Provisional Application No. 62/926,183 filed Oct. 25, 2019, the entire contents of which are incorporated herein by reference.
Number | Date | Country | |
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62926183 | Oct 2019 | US |