Brush burnout prevention device

Abstract

To use a current-collector brush with no waste without damaging a collector ring.SOLUTION: A brush burnout prevention device 400 is constituted so as to, when a current-collector brush 104 in a rotary electric machine abuts on a collector ring 301 at a first position that is a closer side of the collector ring 301 in a radial direction of the collector ring 301 than a side of a grommet 406 connecting a lead cable 106 to the current-collector brush 104, output an alarm signal to restrict movement, to the collector ring 301 side, of the current-collector brush 104 that abuts on the collector ring 301 at a second position that is a closer side of the grommet 406 than the first position and is closer to the collector ring 301 side than the grommet 406 in the radial direction of the collector ring 301.SELECTED DRAWING: Figure 6

Description

[Technical field]

[0001] The present invention relates to a brush burnout prevention device that prevents burnout of a collector ring in a rotating electric machine. [Background technology]

[0002] Hydroelectric power plants are equipped with an exciter unit that supplies an excitation current to the field coil. The exciter unit has brushes such as carbon brushes, and supplies the excitation current to the field coil through the brushes. Since the brushes wear with use, the amount of wear is controlled by measuring the brush dimensions during regular patrols and equipment inspections. The brushes abut against a collector ring, electrically connecting the rotating and stationary parts of the rotating electric machine. The brushes are held by a brush holder.

[0003] The brushes are replaced periodically to prevent damage to the collector ring caused by the brush holder that holds the brush or the grommet that connects the lead cable to the current collecting brush coming into contact with the collector ring due to wear caused by the brush sliding against the collector ring. Conventionally, the timing of brush replacement was determined by, for example, measuring the brush dimensions or visually inspecting the appearance when the generator was stopped. To prevent damage to the collector ring due to brush wear, the brushes were replaced early.

[0004] Specifically, related technologies include a conventional technology relating to a brush abnormality detection device for a rotating electric machine, which determines that a brush has worn and activates an alarm device based on the detection of current flowing from the battery to the switching element when, for example, wear detection contacts fixed to the brushes in the rotating electric machine come into contact with a slip ring as the brushes wear, and a switch and switching element provided between the battery and the wear detection contacts turn on (see, for example, Patent Document 1 below). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2014-79109 A Summary of the Invention [Problem to be solved by the invention]

[0006] However, in the conventional technology described in Patent Document 1 mentioned above, when considering actual use, taking into account the preparation time required for replacement work, such as preparing a new brush for replacement and making a work plan after the alarm is issued, the alarm is issued well before the brush reaches its true wear limit, so the brush must be replaced even though it is still usable, and the still usable brush must be discarded, resulting in waste.

[0007] Furthermore, as described above, in the conventional technology described in Patent Document 1, the true wear limit of the brush has not been reached at the time the alarm is issued. Therefore, if the brush is continued to be used after the alarm is issued by the prior art technology, there is a problem that the brush holder or grommet may come into contact with the collector ring, causing damage to the collector ring.

[0008] Furthermore, in the conventional technology described in Patent Document 1 mentioned above, the rate at which the brush wear progresses is not constant, and the actual degree of wear of the brush is difficult to grasp without stopping the rotating motor and measuring the dimensions. Therefore, when using the conventional technology described in Patent Document 1 mentioned above and continuing to use the brush after an alarm is issued, it is necessary to frequently stop the rotating motor and measure the dimensions of the brush in order to prevent damage to the collector ring, which is a hassle.

[0009] SUMMARY OF THE PRESENT INVETION In order to solve the above-mentioned problems of the prior art, it is an object of the present invention to provide a brush burnout prevention device which can efficiently use the current collecting brush without damaging the collector ring.

[0010] Another object of the present invention is to provide a brush burnout prevention device that can eliminate the problems associated with the prior art described above, and that can use the current collecting brush efficiently without requiring complicated management and without damaging the collector ring. [Means for solving the problem]

[0011] In order to solve the above-mentioned problems and achieve the object, the brush burnout prevention device of the present invention is characterized by comprising: an alarm means for outputting an alarm signal that triggers an alarm output when a collecting brush in a rotating electric machine that converts mechanical energy into electrical energy abuts against the collector ring at a first position that is closer to the collector ring in the radial direction of the collector ring than a grommet that connects a lead cable to the collecting brush; and a restricting member that restricts movement of the collecting brush toward the collector ring when the collecting brush abuts against the collector ring at a second position that is closer to the grommet than the first position and closer to the collector ring than the grommet in the radial direction of the collector ring.

[0012] In addition, the brush burn prevention device of the present invention, in the above invention, is characterized in that it is provided with an interlocking member connected to the collecting brush and displaced in conjunction with the displacement of the collecting brush due to wear, and the regulating member is formed using a material exhibiting a predetermined hardness, and when the collecting brush reaches a position where it abuts against the collector ring at the second position, it engages with the interlocking member, thereby regulating the movement of the collecting brush abutting against the collector ring at the second position toward the collector ring.

[0013] In the brush burnout prevention device according to the present invention, in the above-mentioned invention, the regulating member is provided so as to be adjustable in the position where it engages with the interlocking member.

[0014] In addition, the brush burn prevention device of the present invention is characterized in that, in the above invention, the alarm means outputs the alarm signal when the interlocking member reaches a position where the collecting brush abuts against the collector ring at the first position.

[0015] In addition, in the brush burnout prevention device according to the present invention, in the above-mentioned invention, the warning means is a microswitch having an actuator portion provided on the movement path of the interlocking member.

[0016] In addition, the brush burnout prevention device according to the present invention is characterized in that, in the above invention, the microswitch is attached so that its position can be adjusted along the movement trajectory of the interlocking member.

[0017] In addition, the brush burn prevention device of the present invention is characterized in that, in the above invention, the alarm means outputs an alarm signal which triggers an alarm output by displaying a predetermined guidance message on a display device provided on the rotating electric machine.

[0018] In addition, the brush burn prevention device of the present invention is characterized in that, in the above invention, the alarm means outputs an alarm signal which triggers an alarm output by causing an illuminator provided in the rotating electric machine to emit light in a predetermined pattern.

[0019] In addition, the brush burn prevention device of the present invention is characterized in that, in the above invention, the alarm means outputs an alarm signal which triggers an alarm output by outputting a predetermined sound from at least one of a buzzer and a speaker equipped in the rotating electric machine.

[0020] In addition, the brush burnout prevention device of the present invention is characterized in that, in the above invention, it further comprises a stop means for outputting a stop signal which triggers the stopping of operation of the rotating electric machine based on the value of the current flowing through the lead cable. Effect of the Invention

[0021] According to the brush burnout prevention device of the present invention, it is possible to effectively use the current collecting brush without damaging the collector ring.

[0022] Furthermore, the brush burnout prevention device according to the present invention has the effect of eliminating the need for complicated management, and enabling the current collecting brush to be used efficiently without damaging the collector ring. [Brief description of the drawings]

[0023] [Figure 1] FIG. 1 is an explanatory diagram (part 1) showing the configuration of a rotating electric machine. [Diagram 2] FIG. 2 is an explanatory diagram (part 2) showing the configuration of a rotating electric machine. [Diagram 3] FIG. 3 is an explanatory diagram (part 3) showing the configuration of a rotating electric machine. [Figure 4] 1 is an explanatory diagram showing a configuration of a brush burnout prevention device according to an embodiment of the present invention; [Diagram 5] 4 is an explanatory diagram (part 1) showing the operation of the brush burnout prevention device according to the embodiment of the present invention. FIG. [Figure 6] 5 is an explanatory diagram (part 2) showing the operation of the brush burnout prevention device according to the embodiment of the present invention. FIG. [Figure 7] FIG. 4 is an explanatory diagram showing a worn state of a current collecting brush. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0024] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of a brush burnout prevention device according to the present invention will be described in detail below with reference to the accompanying drawings.

[0025] (Configuration of Rotating Electric Machine) First, the configuration of the rotating electric machine will be described. Figures 1 to 3 are explanatory diagrams showing the configuration of the rotating electric machine. Figure 1 shows the entire rotating electric machine. Figure 2 shows a part of Figure 1 as seen from the direction of arrow A. Figure 3 shows a part of Figure 2 as seen from the direction of arrow B.

[0026] As shown in Figs. 1 to 3, a rotating electric machine 100 includes a casing 101 that houses a stator and a rotor. The stator includes a substantially cylindrical iron core and a coil wound around the iron core (not shown). The rotor is disposed on the inner periphery of the stator (not shown). The rotor is disposed rotatably around the axis of the stator. The rotor is connected to an excitation unit 103 via a shaft 102.

[0027] The magnetic excitation unit 103 includes a collector ring 301 and a current collecting brush 104. The collector ring 301 is annular and made of a conductive material such as a metal material. The collector ring 301 is disposed concentrically with the shaft 102 and rotates with the rotation of the shaft 102.

[0028] The current collecting brush 104 is formed by molding a conductive material into a block shape. The current collecting brush 104 has a substantially rectangular parallelepiped shape (rectangular parallelepiped shape) composed of six faces. One of the six faces constituting the current collecting brush 104 is curved so as to be concave inward of the current collecting brush 104 in accordance with the shape of the outer circumferential surface of the collector ring 301 (see FIG. 4, etc.).

[0029] 3, the current collecting brush 104 is disposed between a pair of plate-like members 302 constituting the brush holder 105. The pair of plate-like members 302 are disposed opposite each other along the axial direction of the shaft 102. The current collecting brush 104 is held by the brush holder 105 so as to be sandwiched between the pair of plate-like members 302 in a state in which the current collecting brush 104 can slide along the plate surfaces of the pair of plate-like members 302.

[0030] The brush holder 105 is provided with a biasing member (not shown) that biases the current collecting brush 104 in a direction in which it comes into contact with the collector ring 301. The biasing member can be realized, for example, by a compression spring. The current collecting brush 104, which is in contact with the collector ring 301 by the biasing force of the biasing member, wears due to friction with the collector ring 301 as the collector ring 301 rotates. Since the current collecting brush 104 is biased by the biasing member in a direction in which it comes into contact with the collector ring 301, when it wears, it slides toward the collector ring 301 by the amount of wear, and is always in contact with the collector ring 301.

[0031] A through hole (see FIG. 4, etc.) that penetrates the current collecting brush 104 in the thickness direction of the current collecting brush 104 is provided on the side opposite to the position where the current collecting brush 104 is curved to match the shape of the outer circumferential surface of the collector ring 301. A metal grommet is provided in the through hole (see FIG. 4, etc.). The grommet connects one end of the lead cable 106 to the current collecting brush 104. Electricity collected from the collector ring 301 via the current collecting brush 104 is sent to the generator via the lead cable 106 and is used to excite the generator.

[0032] The rotating electric machine 100 includes a control unit (not shown). The control unit includes a CPU, a memory, an input / output I / F, etc. The control unit controls the drive of each unit included in the rotating electric machine 100 by executing a control program stored in the memory using the CPU. The memory stores a program that controls each unit included in the rotating electric machine 100 based on a signal input via the input / output I / F, for example.

[0033] The input / output I / F receives input of various signals output from various sensors (not shown) included in the rotating electric machine 100. The input / output I / F outputs the received input signals to the CPU. The input / output I / F is also controlled by the CPU to output control signals to each unit included in the rotating electric machine 100.

[0034] Specifically, the control unit executes a control program stored in a memory using a CPU based on a signal received as an input via the input / output I / F, and outputs a predetermined control signal via the input / output I / F to each unit included in the rotating electric machine 100, thereby performing control to stop the operation of the rotating electric machine 100. The input / output I / F may also communicate with a computer device that remotely controls the rotating electric machine 100. This allows the rotating electric machine 100 to be remotely controlled.

[0035] (Configuration of brush burnout prevention device) Next, the configuration of the brush burnout prevention device according to the embodiment of the present invention will be described. Fig. 4 is an explanatory diagram showing the configuration of the brush burnout prevention device according to the embodiment of the present invention. As shown in Fig. 4, the brush burnout prevention device 400 according to the embodiment of the present invention includes an arm 401, a wear detection unit 402, a stopper mechanism 403, and a current detection unit 404.

[0036] In the brush burnout prevention device 400, the arm 401, the wear detection unit 402, and the stopper mechanism 403 are supported by a support member 405. The support member 405 is attached to one of the pair of plate-like members 302 that constitute the brush holder 105. The support member 405 can be formed, for example, from a sheet metal member.

[0037] The arm 401 is provided between a pair of plate-like members 302 constituting the brush holder 105, and is rotatable along the plate surfaces of the pair of plate-like members 302 (support members 405). The arm 401 is bent in the longitudinal direction to have a generally V-shape. One end of the arm 401 in the longitudinal direction is connected to the shaft 102 so as to be rotatable about an axis parallel to the axis of the shaft 102. The other end of the arm 401 in the longitudinal direction is connected to the brush. The arm 401 rotates in response to wear of the brush caused by being biased by the biasing member. In this embodiment, the arm 401 can realize the interlocking member according to the present invention.

[0038] Wear detection unit 402 can be realized by a microswitch. The Japanese Electrical Control Equipment Industries Association (NECA) defines a microswitch as "a small-sized switch with a minute contact gap and a snap action mechanism, with a contact mechanism that opens and closes with a specified movement and force, covered by a case, and equipped with an actuator on the outside."

[0039] Specifically, the microswitch is composed of an actuator unit, a snap action mechanism unit, a contact unit, a terminal unit, and a case unit. The actuator unit contacts arm 401 to transmit external force received from arm 401 to the internal mechanism. The actuator unit can be realized in various known shapes, for example, a pin push button type, a hinge lever type, a hinge roller lever type, etc. The snap action mechanism unit is composed of a movable spring, a movable piece, a common terminal, a receiving metal, etc. The contact unit switches the circuit on / off. The terminal unit connects the microswitch to an external circuit. The case unit protects the snap action mechanism and the contact unit.

[0040] The microswitch is disposed at a position where the actuator part is positioned on the rotation trajectory of arm 401 by support member 405. Specifically, for example, in the case of a pin push button type actuator part, the microswitch is disposed at a position where the pin push button is pushed into the inside of the case part by the passage of arm 401.

[0041] The microswitch is positioned at a position where the actuator portion comes into contact with the arm 401 when the current collecting brush 104 is positioned at a position where it abuts against the collector ring 301 at the first position. The first position is a contact position of the current collecting brush 104 with the collector ring 301 in the radial direction of the collector ring 301, which is set on the grommet 406 side of the curved surface of the current collecting brush 104 in an unused state and on the collector ring 301 side of the grommet 406.

[0042] The contact position of the microswitch with arm 401 may be freely changeable. Specifically, for example, a groove or slit curved along the rotation trajectory of arm 401 is provided in support member 405 attached to brush holder 105, and a part of the case of the microswitch is fitted into this groove or slit, and the microswitch is slid along the groove or slit, thereby making it possible to freely change the contact position of the microswitch with arm 401.

[0043] The terminal portion of the microswitch is connected to the control unit of the rotating electric machine 100. When the microswitch is in an ON state, it outputs an alarm signal to the control unit of the rotating electric machine 100 via the terminal portion. In this embodiment, the alarm means according to the present invention can be realized by the microswitch that realizes the wear detection unit 402. The alarm signal is a signal that triggers an alarm output by the control unit, and when the control unit of the rotating electric machine 100 receives an input of the alarm signal output from the microswitch, it outputs an alarm by controlling an output device provided in the rotating electric machine 100.

[0044] The output device can be realized by, for example, a display. In this case, the display can be realized by, for example, a liquid crystal display that displays the state of the rotating electric machine 100. When the control unit of the rotating electric machine 100 receives an input of the alarm signal output from the microswitch, it outputs an alarm by, for example, causing the display to display a predetermined guidance message.

[0045] Furthermore, in addition to or instead of the display, the output device may be realized by, for example, an illuminant such as an LED that turns on or off depending on the state of the rotating electric machine 100. In this case, when the control unit of the rotating electric machine 100 receives an input of an alarm signal output from the microswitch, it outputs an alarm by blinking the illuminant or by making the illuminant emit light in a predetermined color.

[0046] The output device may be realized by a device for outputting sound, such as a buzzer or a speaker, provided in the rotating electric machine 100, instead of or in addition to the display. The output device is not limited to one provided integrally with the rotating electric machine 100, but may be realized by an external device connected to the rotating electric machine 100. Specifically, a predetermined signal may be output to a computer device that monitors the operating status of the rotating electric machine 100 or that remotely controls the rotating electric machine 100.

[0047] The stopper mechanism 403 includes a claw member 407 and a stopper member 408. The claw member 407 is provided at a bent portion of the arm 401, and protrudes along the rotation axis direction of the arm 401. In Fig. 4, the claw member 407 protrudes from the arm 401 toward the front side of the page. The claw member 407 can be formed integrally with the arm 401, for example, by sheet metal processing of a metal sheet member. Alternatively, the claw member 407 may be formed separately from the arm 401, and joined to the arm 401 by welding, for example.

[0048] The stopper member 408 is attached to the support member 405. The stopper member 408 is provided on a rotation path of the claw member 407 that occurs when the arm 401 rotates. In Fig. 4, the stopper member 408 is disposed on the front side of the paper surface relative to the arm 401, and protrudes in the front direction of the paper surface. The stopper member 408 may be attached directly to the brush holder 105, or may be attached via a stay as shown in Fig. 4.

[0049] Stopper member 408 is provided at a position where it comes into contact with claw member 407 provided on arm 401 that rotates following current collecting brush 104 when current collecting brush 104 is positioned at a position where it comes into contact with collector ring 301 at the second position. The second position is a contact position of current collecting brush 104 with collector ring 301 in the radial direction of collector ring 301, and is set closer to grommet 406 than the first position and closer to collector ring 301 than grommet 406.

[0050] The second position is preferably set to a limit position where grommet 406 does not come into contact with collector ring 301 even when it rubs against collector ring 301, that is, a so-called wear limit position of current collecting brush 104. When the contact position of current collecting brush 104 with collector ring 301 is located closer to grommet 406 than the wear limit position of current collecting brush 104, grommet 406 comes into contact with collector ring 301. The second position is set between the wear limit position of current collecting brush 104 and the first position. The wear limit position of current collecting brush 104 differs depending on, for example, the type and size of current collecting brush 104.

[0051] As a result, when current collecting brush 104, which slides in the direction pressed against collector ring 301 as it wears, wears to a position where the second position abuts against collector ring 301, claw member 407 and stopper member 408 provided on arm 401, which rotates following current collecting brush 104, come into contact with each other. In this embodiment, the restricting member according to the present invention can be realized by claw member 407 and stopper member 408.

[0052] The position where the claw member 407 and the stopper member 408 come into contact may be adjustable. Specifically, for example, the stopper member 408 may be provided so as to be slidable along the length direction of the stay. Alternatively, specifically, for example, a plurality of holes or apertures may be provided in the stay, and protrusions that fit into the holes or apertures may be provided in the stopper member 408, so that the holes or apertures into which the protrusions of the stopper member 408 fit may be changed.

[0053] This allows, for example, the position of the stopper member 408 to be adjusted in accordance with operation. In this case, the stay may be in an arc shape that follows the rotation trajectory of the arm 401. By adjusting the position of the stopper member 408, the position where the claw member 407 abuts against the stopper member 408, i.e., the second position, can be adjusted.

[0054] The second position can be adjusted as desired by an operator depending on, for example, the conditions at the site. Specifically, in a hydroelectric power plant where an operator is always present, the second position is set at the wear limit position of the current collecting brush 104, which is at the very edge of the grommet 406. This allows the current collecting brush 104 to be used effectively, and also makes it possible to take measures to quickly resume power generation even if the current collecting brush 104 has worn down to the wear limit position.

[0055] Arm 401, claw member 407, and stopper member 408 are all formed using a material that exhibits hardness such that they do not deform even when a biasing force is applied by a biasing member in a state in which claw member 407 and stopper member 408 are in contact with each other. Specifically, arm 401, claw member 407, and stopper member 408 can be formed using a metal material such as iron or stainless steel.

[0056] The current detection unit 404 detects the value of a current flowing through the lead cable 106. The current detection unit 404 can be realized by, for example, a CT type current sensor. Alternatively, the current detection unit 404 may be realized by, for example, a Hall element type current sensor, a Rogowski coil type current sensor, or the like. The current detection unit 404 outputs a signal related to the detected current value to the control unit of the rotating electric machine 100.

[0057] When the current value detected by the current detection unit 404 is equal to or lower than a predetermined threshold value, the control unit of the rotating electric machine 100 performs control to stop the operation of the rotating electric machine 100. In this case, the signal output by the current detection unit 404 realizes a stop signal that triggers the operation of the rotating electric machine 100 to be stopped.

[0058] Only when the detected current value is equal to or less than a predetermined threshold value, the current detection unit 404 may output a stop signal to the control unit of the rotating electric machine 100. In this embodiment, the current detection unit 404 can realize the stop means according to the present invention.

[0059] (Operation of brush burnout prevention device 400) Next, the operation of the brush burnout prevention device 400 according to the embodiment of the present invention will be described with reference to Figs. 4 to 6. Figs. 5 and 6 are explanatory diagrams showing the operation of the brush burnout prevention device 400 according to the embodiment of the present invention. As described above, the current collecting brush 104 is biased by the biasing member and abuts against the collector ring 301. When the current collecting brush 104 is not worn, as shown in Fig. 4, the claw member 407 of the arm 401 is separated from the stopper member.

[0060] The current collecting brush 104 becomes worn due to rubbing against the rotating collector ring 301. Since the current collecting brush 104 is biased by a biasing member in a direction in which it is pressed against the collector ring 301, the current collecting brush 104 slides toward the collector ring 301 by the amount of wear so that it is always in contact with the collector ring 301.

[0061] When the current collecting brush 104 wears down to the first position, the arm 401 comes into contact with the microswitch of the wear detection unit 402, and the microswitch turns ON. The actuator unit of the microswitch comes into contact with the arm 401 before the claw member 407 of the arm 401 abuts against the stopper member 408. When the microswitch turns ON, it outputs an alarm signal to the control unit of the rotating electric machine 100.

[0062] The rotating electric machine 100 continues to operate even after the current collecting brush 104 has worn down to the point where it abuts against the collector ring 301 at the first position. As a result, the current collecting brush 104 wears down beyond the first position and abuts against the collector ring 301 at the second position. When the current collecting brush 104 wears down to the point where it abuts against the collector ring 301 at the second position, the claw member 407 abuts against the stopper member 408. This restricts the movement of the current collecting brush 104 toward the collector ring 301 thereafter.

[0063] If the rotating electric machine 100 continues to rotate the collector ring 301 even after the current collecting brush 104 has worn down to the point where it abuts against the collector ring 301 at the second position, the current collecting brush 104 will wear down until it is no longer in complete contact with the collector ring 301. When the current collecting brush 104 is no longer in contact with the collector ring 301 or the contact becomes insufficient, the value of the current flowing through the lead cable 106 via the grommet 406 changes.

[0064] As a result, the current value detected by the current detection unit 404 changes depending on the contact state of the current collecting brush 104 with the collector ring 301. Then, as described above, when the current detection unit 404 outputs a signal (stop signal) related to the detected current value to the control unit of the rotating electric machine 100, the control unit of the rotating electric machine 100 performs control to stop the operation of the rotating electric machine 100 if the current value detected by the current detection unit 404 is equal to or lower than a predetermined threshold value.

[0065] (Wear condition of current collecting brush 104) Next, the wear state of the current collecting brush 104 will be described. Fig. 7 is an explanatory diagram showing the wear state of the current collecting brush 104. As shown in Fig. 7, the current collecting brush 104 gradually wears down due to rubbing against the rotating collector ring 301. As a result, the contact position 701 of the current collecting brush 104 with the collector ring 301, indicated by reference numeral 701 in Fig. 7, moves toward the grommet 406 as the current collecting brush 104 wears down. Since the current collecting brush 104 is disposed between a pair of plate-like members 302 that constitute the brush holder 105, the wear state cannot be checked while the rotating electric machine 100 is in operation.

[0066] For this reason, conventionally, the current collecting brush 104 was replaced when it was worn down by the amount shown by the arrow 710 in Fig. 7. In contrast, in the brush burnout prevention device 400 of this embodiment, the contact position 701 of the current collecting brush 104 with the collector ring 301 when it is worn down by the amount shown by the arrow 710 in Fig. 7 is defined as a first position, and the current collecting brush 104 can be used from the first position 701 to a second position 702.

[0067] This allows the current collecting brush 104 to be used until it wears down by the amount shown by the arrow 720 in Fig. 7. This allows the brush burnout prevention device 400 to effectively utilize the difference between the amount of wear in the current collecting brush 104 shown by the arrow 720 and the amount of wear shown by the arrow 710 in Fig. 7.

[0068] As described above, the brush burnout prevention device 400 of the embodiment of the present invention is characterized in that it outputs an alarm signal when the current collecting brush 104 abuts against the collector ring 301 at the first position, and restricts the movement of the current collecting brush 104 toward the collector ring 301 when the current collecting brush 104 abuts against the collector ring 301 at the second position.

[0069] According to the brush burnout prevention device 400 of the embodiment of the present invention, an alarm is output when the current collecting brush 104 has worn down to the point where it abuts against the collector ring 301 at a first position, based on the positional relationship between the abutment position of the current collecting brush 104 against the collector ring 301 and the grommet 406 in the radial direction of the collector ring 301, and once the current collecting brush 104 has worn down further and abutted against the collector ring 301 at a second position closer to the grommet 406 than the first position, movement of the current collecting brush 104 toward the collector ring 301 can be restricted.

[0070] This allows the wear state of the current collecting brush 104 to be notified early before the current collecting brush 104 wears down to its limit, and allows the current collecting brush 104 to be used even after an alarm is output. Furthermore, by preventing the current collecting brush 104 from wearing down further when it has worn down to its limit, it is possible to reliably prevent the grommet 406 from coming into contact with the collector ring 301, and therefore the current collecting brush 104 can be used efficiently without damaging the collector ring 301.

[0071] Furthermore, by notifying the wear state of the current collecting brush 104 before restricting the movement of the current collecting brush 104 toward the collector ring 301, the worker can prepare a new current collecting brush 104 for replacement or plan the replacement work in good time after the alarm is output, before the current collecting brush 104 is worn down to its limit. This allows the current collecting brush 104 to be used efficiently without damaging the collector ring 301 and without requiring complicated management.

[0072] In addition, the brush burnout prevention device 400 of an embodiment of the present invention is characterized in that it is equipped with an arm 401 that is connected to the current collecting brush 104 and displaces in conjunction with the displacement of the current collecting brush 104 due to wear, and when the current collecting brush 104 reaches a position where it abuts against the collector ring 301 at the second position, a claw member 407 and a stopper member 408 formed using a material exhibiting a predetermined hardness engage with each other, thereby restricting the movement of the current collecting brush 104 abutting against the collector ring 301 at the second position toward the collector ring 301.

[0073] According to the brush burnout prevention device 400 of the embodiment of the present invention, the displacement of the interlocking member connected to the current collecting brush 104 is mechanically restricted, thereby reliably preventing the grommet 406 from contacting the collector ring 301. This allows the current collecting brush 104 to be used efficiently without damaging the collector ring 301.

[0074] In addition, the brush burnout prevention device 400 of the embodiment of the present invention is characterized in that it outputs an alarm signal when the arm 401 reaches a position where the collecting brush 104 abuts against the collector ring 301 in the first position.

[0075] According to the brush burnout prevention device 400 of the embodiment of the present invention, it is possible to output an alarm based on the position of an interlocking member that is interlocked with the displacement of the current collecting brush 104, which gradually wears, without directly monitoring the contact position 701 between the collector ring 301, which rotates at high speed, and the current collecting brush 104. This makes it possible to separate the mechanism that detects the wear state of the current collecting brush 104 from the contact position 701. This makes it possible to reliably prevent damage to the collector ring 301.

[0076] In addition, the brush burnout prevention device 400 according to the embodiment of the present invention is characterized in that it outputs an alarm signal by utilizing a microswitch equipped with an actuator unit provided on the movement path of the interlocking member.

[0077] According to the brush burnout prevention device 400 of the embodiment of the present invention, it is possible to mechanically detect the position of the current collecting brush 104. This makes it possible to reliably detect that the current collecting brush 104 has reached a position where it abuts against the collector ring 301 at the first position, and to reliably notify the wear state of the current collecting brush 104 before the current collecting brush 104 is worn down to its limit.

[0078] In addition, by using a microswitch, it is possible to reliably detect the position of the current collecting brush 104 and prevent the brush burnout prevention device 400 from becoming large. This allows the brush burnout prevention device 400 to be installed in the limited space inside the brush holder 105.

[0079] Further, the brush burnout prevention device 400 according to the embodiment of the present invention is characterized in that the operation of the rotating electrical machine 100 is stopped based on the value of the current flowing through the lead cable 106 .

[0080] According to the brush burnout prevention device 400 of the embodiment of the present invention, when the current collecting brush 104 is worn down to its limit, the operation of the rotating electric machine 100 can be stopped. This prevents the rotating electric machine 100 from operating in a state where the current collecting brush 104 is not in sufficient contact with the collector ring 301, and prevents the generated electricity from being charged without being collected, thereby ensuring the safety of the rotating electric machine 100 and the surrounding area of ​​the rotating electric machine 100. [Industrial Applicability]

[0081] As described above, the brush burnout prevention device of the present invention is useful as a brush burnout prevention device that prevents burnout of the collector ring in a rotating electric motor, and is particularly suitable as a brush burnout prevention device that prevents burnout of the collector ring in a rotating electric motor while making effective use of the current collecting brush. [Explanation of symbols]

[0082] 100 Rotating Electric Machine 102 Shaft 103 Excitation section 104 Collector brush 105 Brush holder 301 Collector's Ring 400 Brush burnout prevention device 401 Arm 402 Wear detection unit 403 Stopper mechanism 404 Current detection section 405 Support member 406 Grommet 407 Claw parts 408 Stopper member

Claims

1. an alarm means for outputting an alarm signal which triggers an alarm output when a current collecting brush in a rotating electric machine which converts mechanical energy into electrical energy comes into contact with the collector ring at a first position which is closer to the collector ring in a radial direction of the collector ring than a grommet which connects a lead cable to the current collecting brush; a stopper member that restricts movement of the current collecting brush toward the collector ring, the current collecting brush abutting against the collector ring at a second position that is closer to the grommet than the first position and closer to the collector ring than the grommet in a radial direction of the collector ring; a linking member that is provided between a pair of plate-like members and rotatable along plate surfaces of the pair of plate-like members, that is connected to the current collecting brush, and that displaces in conjunction with the displacement of the current collecting brush due to wear; Equipped with the stopper member is formed using a material exhibiting a predetermined hardness, and when the current collecting brush reaches a position where it abuts against the collector ring at the second position, it engages with the interlocking member to restrict movement of the current collecting brush abutting against the collector ring at the second position toward the collector ring, The warning means is composed of a microswitch equipped with an actuator part provided on the movement trajectory of the interlocking member of the support member attached to the plate-shaped member, and when the interlocking member reaches a position where the collecting brush abuts the collector ring at the first position, the side part in the movement direction of the interlocking member begins to come into contact with the actuator part, and thereafter, the side part continues to be in contact with the actuator part until the interlocking member and the stopper member engage, and during that time, the microswitch is in the ON state, thereby outputting a warning signal.

2. 2. The brush burnout prevention device according to claim 1, wherein the stopper member is provided so as to be adjustable in a position where it engages with the interlocking member.

3. 3. The brush burnout prevention device according to claim 1, wherein the microswitch is attached so as to be positionally adjustable along a moving path of the interlocking member.

4. The brush burnout prevention device according to any one of claims 1 to 3, characterized in that the warning means outputs a warning signal which triggers a warning output by displaying a predetermined guidance message on a display device provided on the rotating electric machine.

5. The brush burnout prevention device according to any one of claims 1 to 3, characterized in that the alarm means outputs an alarm signal that triggers an alarm output by causing an illuminator provided in the rotating electric machine to emit light in a predetermined pattern.

6. The brush burnout prevention device described in any one of claims 1 to 3, characterized in that the alarm means outputs an alarm signal that triggers an alarm output by outputting a predetermined sound from at least one of a buzzer and a speaker equipped in the rotating electric machine.

7. The brush burnout prevention device according to any one of claims 1 to 6, further comprising a stop means for outputting a stop signal that triggers the stopping of operation of the rotating electric machine based on the value of the current flowing through the lead cable.

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