JP2014079109A - Brush abnormality detector for rotary electric machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a brush abnormality detector for a rotary electric machine that can detect abrasion of a brush by using an existing electrical circuit.SOLUTION: When a brush 5a is abrading away, a moving contact point 7a fixed to the brush 5a approaches to a slip ring 4a, and finally comes into contact with the slip ring 4a. When a switch 10 and a switching element S4 are turned on under this state, current from a battery 9 successively flows through the switch 10, the moving contact point 7a, the slip ring 4a, the brush 5a, an output terminal Pu and the switching element S4. At this time, the current is detected by an ammeter 11, and the detection value is transmitted to ECU 13. Upon the current detection of the ammeter 11, ECU 13 determines that any one of brushes 5a, 5b, 5c is worn, and actuates an alarm device 14.

Description

  The present invention relates to a brush abnormality detection device for a rotating electrical machine.

  A rotating electrical machine such as a motor generally has a stator fixed to a casing, a rotor that can rotate relative to the stator, and a brush device that supplies electric power to the rotor. The brush device is configured to press the brush against a slip ring provided on the outer periphery of the rotating shaft. Since the brush is fixed to the brush holder, the slip ring rotates together with the rotating shaft, so that the brush and the slip ring rub against each other during operation of the rotating electrical machine. Since the brush is generally made of carbon and the slip ring is made of metal, the brush is worn by rubbing the two.

  It is important to detect the wear of the brush at an appropriate timing because the brush will not conduct when the brush reaches the wear limit. Japanese Patent Application Laid-Open No. 2004-228867 discloses a motor that detects brush wear and issues an alarm. In this motor, the second brush having a length shorter than that of the main brush is electrically insulated and integrally provided. When the main brush is worn and the second brush comes into contact with the commutator of the motor, the main brush It is determined that the wear has occurred and an alarm is issued.

JP 2002-369460 A

  However, the motor disclosed in Patent Document 1 has a problem that a wear detection circuit for detecting the wear of the main brush and issuing an alarm must be provided separately. In addition, when a wear detection circuit is provided, it may be affected by vibration or electromagnetic noise.

  The present invention has been made to solve such problems, and an object of the present invention is to provide a brush abnormality detection device for a rotating electrical machine capable of detecting brush wear using an existing electric circuit.

A brush abnormality detection device for a rotating electrical machine according to the present invention includes at least one slip ring provided to rotate with a rotating shaft of the rotating electrical machine, at least one brush provided to contact the slip ring, and a brush. A battery for supplying electric power to the rotating electrical machine, an inverter provided between the battery and the brush, an inverter having a plurality of switching elements, at least one ammeter for detecting a current flowing through any of the plurality of switching elements, and a brush Wear detection contact for electrically connecting a battery and a switching element capable of detecting current with an ammeter based on the wear state of the battery via a brush, and a switch provided between the battery and the wear detection contact And an abnormality determination means, the abnormality determination means is a switch and switching that can detect current with an ammeter When turning on the child, for detecting the wear of the brush when the ammeter detects current.
The wear detection contact may include a fixed contact and a moving contact that is fixed to the brush and moves toward the fixed contact together with the brush as the brush wears.
The fixed contact may be a slip ring.
An insulator is provided on the brush to separate the brush into a first part electrically connected to the switch and a second part in contact with the slip ring, and the moving contact is the first part; When the brush is worn, the insulator may be destroyed by the slip ring, and the first portion may contact the slip ring.
The contact for wear detection includes a fixed contact fixed to the brush and a moving contact that moves toward the fixed contact as the brush wears. The brush has a notch that is recessed with respect to its surface. The moving contact may be fixed to the contact member pressed against the surface by the elastic member, and the moving contact may come into contact with the fixed contact when the brush wears and the contact member enters the notch.
A plurality of brushes may be provided, and a contact for wear detection of each brush may be provided in parallel between the switch and the inverter.

Further, a brush abnormality detection device for a rotating electrical machine according to the present invention includes at least one slip ring provided to rotate together with a rotating shaft of the rotating electrical machine, at least one brush provided to contact the slip ring, An abnormality determination circuit including a power source and an ammeter, provided in the abnormality determination circuit, and provided with a wear detection contact connected based on the wear state of the brush, and an abnormality determination means, the wear detection contact, The brush has a fixed contact and a moving contact that moves toward the fixed contact as the brush wears. The brush is provided with a notch that is recessed with respect to the surface, and the moving contact is pressed against the surface by an elastic member. The anomaly judging means is connected to the fixed contact by the moving contact of the moving contact with the fixed contact as the brush wears and the contact member enters the notch. There detecting the wear of the brush when it detects a current. In the motor described in Patent Document 1, the second brush approaches the motor commutator due to wear of the main brush. Even when the wear of the main brush has not reached its limit, the second brush is moved by vibration of the motor shaft. There is a problem that it is detected that the brush is worn by mistake due to contact with the commutator, but in this invention, the contact member does not enter the notch due to vibration, so the brush is mistakenly It is possible to prevent the wear from being detected.
A plurality of brushes may be provided, and in one abnormality determination circuit, a contact for wear detection of each brush may be provided in parallel.

Furthermore, the brush abnormality detection device for a rotating electrical machine according to the present invention includes at least one slip ring provided to rotate together with a rotating shaft of the rotating electrical machine, at least one brush provided to contact the slip ring, An optical fiber fixed to the brush, a light emitting unit for making light incident on the optical fiber, a light receiving unit for receiving the light transmitted through the optical fiber, and an abnormality determining unit. Wear of the brush is detected when the light receiving unit stops detecting the light transmitted through the optical fiber due to the destruction of the optical fiber. In the motor described in Patent Document 1, since a wear detection circuit for detecting the wear of the main brush and issuing an alarm is separately provided, there is a risk of being affected by electromagnetic noise of an existing electric circuit. Since an electric circuit is not used for detection of brush wear, the influence of electromagnetic noise of an existing electric circuit can be eliminated.
An optical fiber provided with a plurality of brushes and fixed to each brush may be connected in series.

  According to the present invention, when an ammeter that detects a current flowing through any of the plurality of switching elements provided in the inverter detects a current, the wear of the brush is detected, whereby the existing electric circuit and ammeter are It can be used to detect brush wear.

It is the schematic of the brush abnormality detection apparatus of the rotary electric machine which concerns on Embodiment 1 of this invention. It is the schematic of the modification of the brush apparatus in the brush abnormality detection apparatus of the rotary electric machine which concerns on Embodiment 1. FIG. FIG. 3 is a diagram illustrating a part of an electric circuit inside the rotating electrical machine according to the first embodiment. 5 is a schematic diagram of a brush abnormality detection device for a rotating electrical machine according to Embodiment 2. FIG. 6 is a schematic diagram of a brush abnormality detection device for a rotating electrical machine according to Embodiment 3. FIG. 6 is a schematic diagram of a brush abnormality detection device for a rotating electrical machine according to Embodiment 4. FIG. 6 is a schematic diagram of a brush abnormality detection device for a rotating electrical machine according to Embodiment 5. FIG. It is the schematic of the brush abnormality detection apparatus of the rotary electric machine which concerns on Embodiment 6. FIG.

Embodiments of the present invention will be described below with reference to the accompanying drawings.
Embodiment 1 FIG.
FIG. 1 shows a schematic diagram of a brush abnormality detection apparatus for a rotating electrical machine according to Embodiment 1 of the present invention. A brush device 3 including three poles 3a, 3b, and 3c is provided on a rotating shaft 2 of a motor 1 that is a rotating electrical machine. The poles 3a, 3b, and 3c are provided so as to be in contact with the annular slip rings 4a, 4b, and 4c that are fixed to the rotary shaft 2 and can rotate with the rotary shaft 2, and the slip rings 4a, 4b, and 4c, respectively. Brushes 5a, 5b, 5c. Moving contacts 7a, 7b, and 7c are fixed to the brushes 5a, 5b, and 5c via insulators 6a, 6b, and 6c, respectively. As will be described later, when the brushes 5a, 5b, and 5c wear, the moving contacts 7a, 7b, and 7c move toward the slip rings 4a, 4b, and 4c, respectively. 4b and 4c constitute fixed contacts for the moving contacts 7a, 7b and 7c, respectively, and the moving contacts 7a, 7b and 7c and the slip rings 4a, 4b and 4c constitute wear detection contacts, respectively.

  The brushes 5a, 5b, and 5c are electrically connected to the battery 9 through the inverter 8, respectively. The inverter 8 has a pair of switching elements connected in series for three phases, the switching elements S1 and S4 correspond to the u phase, the switching elements S2 and S5 correspond to the v phase, and the switching elements S3 and S3. S6 corresponds to the w phase. The output ends Pu, Pv, and Pw of the u phase, v phase, and w phase are electrically connected to the brushes 5a, 5b, and 5c, respectively. An ammeter 11 is provided between the output terminal Pu and the brush 5a, and an ammeter 12 is provided between the output terminal Pw and the brush 5c.

  The battery 9 is electrically connected to the switch 10 via the conductive wire 16. One end of a conducting wire 15 is connected to the switch 10, and the other end side of the conducting wire 15 branches into three conducting wires 15a, 15b, and 15c, which are connected to the moving contacts 7a, 7b, and 7c, respectively. That is, the switch 10 is provided between the battery 9 and the wear detection contact. With this configuration, each wear detection contact made up of each of the moving contacts 7a, 7b, 7c and each of the slip rings 4a, 4b, 4c is provided in parallel between the switch 10 and the inverter 8.

  The inverter 8, the battery 9, the switch 10, and the ammeters 11 and 12 are each electrically connected to an ECU 13 that is a control device. The ECU 13 is further electrically connected to an alarm device 14 such as a buzzer or a lamp for notifying that at least one of the brushes 5a, 5b, 5c is worn by an operation described later. Here, the ECU 13 constitutes an abnormality determination unit that determines whether at least one of the brushes 5a, 5b, and 5c is worn.

Next, the operation of the brush abnormality detection apparatus for a rotating electrical machine according to Embodiment 1 of the present invention will be described.
When the ECU 13 detects that power supply from the battery 9 to the inverter 8 is started and the motor 1 is started, the ECU 13 turns on the switch 10 and the switching element S4. If none of the brushes 5a, 5b, 5c is worn, the moving contacts 7a, 7b, 7c are not in contact with the slip rings 4a, 4b, 4c, so that they move even when the switch 10 is turned on. No current flows between the contacts 7a, 7b, 7c and the slip rings 4a, 4b, 4c, and the ammeter 11 does not detect the current. In this case, the ECU 13 determines that none of the brushes 5a, 5b, 5c is worn.

  On the other hand, for example, as the brush 5a wears, the distance from the slip ring 4a to the upper surface of the brush 5a, that is, the height of the brush 5a decreases, so that the moving contact 7a fixed to the brush 5a is connected to the slip ring 4a. The moving contact 7a eventually comes into contact with the slip ring 4a. When the switch 10 and the switching element S4 are turned on in this state, the current from the battery 9 sequentially flows through the switch 10, the moving contact 7a, the slip ring 4a, the brush 5a, the output terminal Pu, and the switching element S4. Then, the ammeter 11 detects this current, and the detected value is transmitted to the ECU 13. The ECU 13 determines that any of the brushes 5a, 5b, and 5c is worn based on the fact that the ammeter 11 detects the current, and activates the alarm device 14. Here, the description is made on the assumption that the brush 5a is worn. However, since the wear detection contacts of the brushes 5a, 5b, and 5c are provided in parallel between the switch 10 and the inverter 8, the ECU 13 Cannot specify which of the brushes 5a, 5b, 5c is worn, and determines that any of the brushes 5a, 5b, 5c is worn. Subsequently, the ECU 13 activates the alarm device 14, thereby notifying that any of the brushes 5a, 5b, 5c is worn. When the ECU 13 finishes determining the wear of the brushes 5a, 5b, and 5c, the ECU 13 immediately turns off the switch 10, and current is supplied from the battery 9 to the brushes 5a, 5b, and 5c via the inverter 8, and the motor 1 Starts. When the brushes 5b and 5c are worn, the wear is determined by the same operation.

  Thus, when the ammeter 11 that detects the current flowing through the switching element S4 provided in the inverter 8 detects the current, the wear of the brushes 5a, 5b, and 5c is detected. The ammeter 11 is already installed in the inverter 8, and since the electric circuit through which current flows when the brushes 5a, 5b, 5c are worn is also installed in the inverter 8, the brushes 5a, 5b, 5c It is not necessary to separately provide an ammeter and an electric circuit for detecting wear of the metal. Therefore, the wear of the brushes 5a, 5b, and 5c can be detected using an existing electric circuit.

  In Embodiment 1, the switching element S4 is turned on, but the switching element S6 may be turned on. In this case, when the brush 5a is worn and the moving contact 7a contacts the slip ring 4a, the current from the battery 9 is changed to the switch 10, the moving contact 7a, the slip ring 4a, the brush 5a, the output terminal Pw, and the switching element S6. , And the ammeter 12 detects this current. That is, a switching element that can detect a flowing current with an ammeter may be turned on. As with the ammeter 11, the ammeter 12 is already installed in the inverter 8. Even in this case, an ammeter and an electric circuit for detecting wear of the brushes 5 a, 5 b, and 5 c are separately provided. Is no longer necessary. In addition, an ammeter is not provided between the output terminal Pv and the brush 5b, but the current value to the brush 5b can be estimated based on the detection values by the ammeters 11 and 12. For this reason, the location where the two ammeters are provided may be anywhere between the output ends Pu, Pv, Pw and the brushes 5a, 5b, 5c. Further, an ammeter may be provided between each of the output terminals Pu, Pv, and Pw and each of the brushes 5a, 5b, and 5c to form three ammeters.

  In the first embodiment, the rotary shaft 2 is provided with the three slip rings 4a, 4b, and 4c and the brushes 5a, 5b, and 5c are provided so as to be in contact therewith, but this is not a limitation. As shown in FIG. 2, the rotary shaft 2 may be provided with one slip ring 4 and may be provided with brushes 5 a, 5 b, 5 c so as to be in contact therewith. Also in FIG. 2, each wear detection contact made up of each of the moving contacts 7 a, 7 b, 7 c and the slip ring 4 is provided in parallel between the switch 10 and the inverter 8 (see FIG. 1). It is determined that any of the brushes 5a, 5b, 5c is worn.

  In the first embodiment, the wear detection contacts are provided in parallel between the switch 10 and the inverter 8 in both of the forms shown in FIGS. 1 and 2, but the present invention is not limited to this form. By electrically connecting the battery 9 and each of the moving contacts 7a, 7b, and 7c separately, and providing a switch for each, and turning on each switch in turn, which of the brushes 5a, 5b, and 5c is worn It may be possible to detect whether or not it has been done.

  In the first embodiment, when the switch 10 and the switching element S4 are turned on when the motor 1 is started, the current from the battery 9 is changed to the switch 10, the moving contact 7a, the slip ring 4a, the brush 5a, the output end Pu, Although the wear of the brushes 5a, 5b, and 5c has been detected by sequentially flowing through the switching element S4 and the ammeter 11 detecting this current, the present invention is not limited to this form. When starting the motor 1, the switch 10 and the switching element S6 may be turned on. In this case, the current from the battery 9 sequentially flows through the switch 10, the moving contact 7a, and the slip ring 4a, then flows through the coil in the rotor 17 of the motor 1 (see FIG. 3), and then the slip ring. The wear of the brushes 5a, 5b, and 5c may be detected by sequentially flowing through 4c, the brush 5c, the output terminal Pw, and the switching element S6, and the ammeter 12 detecting this current. In any case, when the moving contact 7a contacts the slip ring 4a, the battery 9 and either the switching element S4 or S6 are electrically connected via the brush 5a or 5c.

Embodiment 2. FIG.
Next, a brush abnormality detection apparatus for a rotating electrical machine according to Embodiment 2 of the present invention will be described. In the following embodiments, the same reference numerals as those in FIGS. 1 to 3 are the same or similar components, and thus detailed description thereof is omitted.
The brush abnormality detection device for a rotating electrical machine according to Embodiment 2 of the present invention is obtained by changing the form of the contact for wear detection with respect to Embodiment 1.

  As shown in FIG. 4, a thin plate-like insulator 20 is provided inside the brush 5 a, and the insulator 20 separates the brush 5 a into a first portion 21 and a second portion 22. . The first portion 21 is connected to the end portion 15a1 of the conducting wire 15a, and the second portion 22 is in contact with the slip ring 4a. The insulator 20 electrically insulates the end 15a1 of the conducting wire 15a from the slip ring 4a. Although not shown in FIG. 4, the brushes 5b and 5c (see FIG. 1) have the same form as the brush 5a. Other configurations are the same as those of the first embodiment.

  Since the second portion 22 of the brush 5a is in contact with the slip ring 4a, the brush 5a is worn by the second portion 22 being scraped by friction with the slip ring 4a. As the second portion 22 is scraped, the first portion 21 and the insulator 20 gradually approach the slip ring 4a. Eventually, the insulator 20 comes into contact with the slip ring 4a, the insulator 20 and the slip ring 4a rub against each other, and the insulator 20 is destroyed. Then, the first portion 21 comes into contact with the slip ring 4a. In this state, when an operation similar to that in the first embodiment is performed, the current from the battery 9 is supplied to the switch 10, the first portion 21, the slip ring 4a, the second portion 22, the output terminal Pu, and the switching element S4 ( The ECU 13 determines that one of the brushes 5a, 5b, 5c is worn. When the brushes 5b and 5c are worn, the wear is determined by the same operation. The insulator 20 is destroyed due to the wear of the brush 5a, and the first portion 21 and the slip ring 4a come into contact with each other. As a result, the current from the battery 9 flows as described above. The first portion 21 constitutes a moving contact and the slip ring 4a constitutes a fixed contact, which constitutes a wear detection contact.

  Thus, the brushes 5a, 5b, and 5c are separated into the first portion 21 that is electrically connected to the switch 10 and the second portion 22 that is in contact with the slip rings 4a, 4b, and 4c. Even if the insulator 20 is provided in 5a, 5b, 5c and the contact for detecting wear is constituted by the first portion 21 and the slip rings 4a, 4b, 4c, the same effect as in the first embodiment can be obtained. .

Embodiment 3 FIG.
Next, a brush abnormality detection apparatus for a rotating electrical machine according to Embodiment 3 of the present invention will be described.
The brush abnormality detection device for a rotating electrical machine according to the third embodiment of the present invention is obtained by changing the form of the contact for wear detection with respect to the first embodiment.
As shown in FIG. 5, a support rod 36 made of a conductive material is provided on the upper surface 5a1 of the brush 5a, and a moving contact 37 provided at the tip thereof is located outside the upper surface 5a1. The moving contact 37 and the brush 5a are electrically connected via the support bar 36. A fixed contact 38 is provided at a position away from the moving contact 37 by a predetermined distance downward in the vertical direction of the moving contact 37. The fixed contact 38 is electrically connected to the switch 10. Although not shown in FIG. 5, the brushes 5b and 5c (see FIG. 1) have the same form as the brush 5a. Other configurations are the same as those of the first embodiment.

  As the brush 5a wears due to friction between the brush 5a and the slip ring 4a and the height of the brush 5a decreases, the moving contact 37 gradually moves downward in the vertical direction, that is, toward the fixed contact 38, Eventually, the moving contact 37 and the fixed contact 38 come into contact. When an operation similar to that of the first embodiment is performed in this state, the current from the battery 9 causes the switch 10, the fixed contact 38, the moving contact 37, the brush 5a, the output terminal Pu, and the switching element S4 (see FIG. 1). The ECU 13 determines that any one of the brushes 5a, 5b, and 5c has been worn because it flows sequentially. When the brushes 5b and 5c are worn, the wear is determined by the same operation.

  As described above, the moving contact 37 provided at the tip of the support rod 36 made of a conductive material provided on the upper surface of the brushes 5a, 5b, 5c so as to be located outside the upper surface, and the vertical direction of the moving contact 37 Even if the wear detection contact is configured from the moving contact 37 and the fixed contact 38 provided at a predetermined distance downward, the same effect as in the first embodiment can be obtained.

  In the third embodiment, the support rod 36 is provided on the upper surfaces of the brushes 5a, 5b, and 5c. However, the present invention is not limited to this configuration. As long as the fixed contact point 38 is provided at a predetermined distance away from the moving contact point 37 downward in the vertical direction of the moving contact point 37, it may be provided on any of the brushes 5a, 5b, 5c. For example, you may provide the support bar 36 in the side surface of brush 5a, 5b, 5c.

Embodiment 4 FIG.
Next, a description will be given of a brush abnormality detection apparatus for a rotating electrical machine according to Embodiment 4 of the present invention.
The brush abnormality detection device for a rotating electrical machine according to Embodiment 4 of the present invention is obtained by changing the form of the contact for wear detection with respect to Embodiment 1.
As shown in FIG. 6A, a notch 40 that is recessed with respect to the side surface 5a2 is formed on the surface of the brush 5a, for example, the side surface 5a2. A contact member 42 is in contact with a side surface 5a2 where the notch 40 is formed by a spring 41 which is an elastic member. Before the brush 5a is worn, the contact member 42 is in contact with the notch 40 at a position below the vertical direction. The brush 5 a is provided with a support bar 49 made of a conductive material, and a fixed contact 48 is provided at the tip of the support bar 49. The fixed contact 48 and the brush 5a are electrically connected via the support bar 49. A support rod 46 made of a conductive material that is electrically connected to the switch 10 via a conducting wire 45 is fixed to the contact member 42. The support rod 46 is provided with a moving contact 47, and the moving contact 47 is located a predetermined distance away from the fixed contact 48 on the opposite side of the notch 40 in the horizontal direction. Although not shown in FIG. 6A, the brushes 5b and 5c (see FIG. 1) also have the same form as the brush 5a. Other configurations are the same as those of the first embodiment.

  As the brush 5a wears due to friction between the brush 5a and the slip ring 4a and the height of the brush 5a decreases, the cutout portion 40 shifts downward in the vertical direction. Along with this, the contact member 42 slides on the side surface 5a2, and the contact member 42 enters the notch 40 as shown in FIG. 6B. Then, together with the contact member 42, the support rod 46 fixed to the contact member 42 and the moving contact 47 provided on the support rod 46 move toward the fixed contact 48, whereby the moving contact 47 is fixed. The contact 48 comes into contact. When the same operation as in the first embodiment is performed in this state, the current from the battery 9 causes the switch 10, the moving contact 47, the fixed contact 48, the brush 5a, the output terminal Pu, and the switching element S4 (see FIG. 1). The ECU 13 determines that any one of the brushes 5a, 5b, and 5c has been worn because it flows sequentially. When the brushes 5b and 5c are worn, the wear is determined by the same operation.

  In this way, the notch 40 that is recessed with respect to the surface of the brush 5a, 5b, 5c is provided, the moving contact 47 is provided on the contact member 42 pressed against the surface of the brush 5a, 5b, 5c by the spring 41, Even if the contact for detecting wear is configured such that the moving contact 47 comes into contact with the fixed contact 48 by the wear of the brushes 5a, 5b, 5c and the contact member 42 entering the notch 40, Embodiment 1 The same effect can be obtained. Further, in the form in which the moving contact gradually approaches the fixed contact as the brushes 5a, 5b, and 5c wear as in the first and third embodiments, when the distance between the moving contact and the fixed contact is shortened, the rotating shaft In the fourth embodiment, the contact member 42 enters the notch 40 in the fourth embodiment, although the two contacted instantaneously due to the vibration of 2 and there was a risk of erroneous detection of the wear of the brushes 5a, 5b, 5c. As a result, the moving contact 47 moves toward the fixed contact 48 so that they come into contact with each other, so that the moving contact 47 is less affected by the vibration of the rotating shaft 2 and the wear detection accuracy of the brushes 5a, 5b, 5c can be improved. .

  In the fourth embodiment, the moving contact 47 is electrically connected to the switch 10 and the fixed contact 48 is electrically connected to the brushes 5a, 5b, and 5c. However, the present invention is not limited to this embodiment. The moving contact 47 may be electrically connected to the brushes 5 a, 5 b, 5 c and the fixed contact 48 may be electrically connected to the switch 10.

Embodiment 5 FIG.
Next, a brush abnormality detection apparatus for a rotary electric machine according to Embodiment 5 of the present invention will be described.
The brush abnormality detection apparatus for a rotating electrical machine according to Embodiment 5 of the present invention is configured to detect brush wear without using ammeters 11 and 12 that are already installed in the inverter 8, as compared with Embodiment 4. Is.
As shown in FIG. 7, a notch 40 that is recessed with respect to the side surface 5a2 is formed on the surface of the brush 5a, for example, the side surface 5a2. A contact member 42 is in contact with a side surface 5a2 where the notch 40 is formed by a spring 41 which is an elastic member. Before the brush 5a is worn, the contact member 42 is in contact with the notch 40 at a position below the vertical direction. The brush 5a is provided with a support bar 59 made of an insulating material, and a fixed contact 48 is provided at the tip of the support bar 59. A support rod 46 made of a conductive material that is electrically connected to the switch 10 via a conducting wire 45 is fixed to the contact member 42. The support rod 46 is provided with a moving contact 47, and the moving contact 47 is located a predetermined distance away from the fixed contact 48 on the opposite side of the notch 40 in the horizontal direction. The brushes 5b and 5c have the same form as the brush 5a.

  There is provided an abnormality determination circuit 50 in which the respective wear detection contacts including the moving contacts 47 and the fixed contacts 48 of the brushes 5a, 5b and 5c are arranged in parallel. The abnormality determination circuit 50 is provided with a power source 51 and an ammeter 52. The battery 9 (see FIG. 6) may be used as the power source 51, or a power source different from the battery 9 may be used. The ammeter 52 is electrically connected to the ECU 13, and the alarm device 14 is further electrically connected to the ECU 13.

  When the brush 5a is worn due to friction between the brush 5a and the slip ring 4a and the height of the brush 5a is reduced, the contact member 42 enters the notch 40 by the same operation as in the fourth embodiment, and thereby moves. The contact 47 comes into contact with the fixed contact 48. Then, a current flows through the abnormality determination circuit 50. The ammeter 52 detects this current, and the detected value is transmitted to the ECU 13, whereby the ECU 13 determines that any of the brushes 5 a, 5 b, 5 c is worn and activates the alarm device 14. When the brushes 5b and 5c are worn, the wear is determined by the same operation.

  In this way, the notch 40 that is recessed with respect to the surface of the brush 5a, 5b, 5c is provided, the moving contact 47 is provided on the contact member 42 pressed against the surface of the brush 5a, 5b, 5c by the spring 41, As the brushes 5a, 5b, and 5c wear and the contact member 42 enters the cutout portion 40, a wear detection contact is configured so that the moving contact 47 contacts the fixed contact 48. By detecting the current flowing through the abnormality determination circuit 50 arranged in parallel by the ammeter 52 provided in the abnormality determination circuit 50, the wear of the brushes 5a, 5b, and 5c can be detected. Also in the fifth embodiment, as in the fourth embodiment, since it is hardly affected by the vibration of the rotating shaft 2, the detection accuracy of the wear of the brushes 5a, 5b, and 5c can be improved.

  In the fifth embodiment, the contact for detecting wear of each of the brushes 5a, 5b, 5c is arranged in parallel in one abnormality determination circuit 50. However, the present invention is not limited to this embodiment. Three abnormality determination circuits including one contact point for wear detection of each brush may be provided. In this case, it can be specified which of the brushes 5a, 5b, 5c is worn.

  In the fifth embodiment, when battery 9 is used as power source 51, it is preferable to provide a switch in abnormality determination circuit 50. When there is no switch, when the brushes 5a, 5b, 5c are worn and the moving contact 47 and the fixed contact 48 come into contact with each other, current continues to flow through the abnormality determination circuit 50, which may hinder power supply to the motor 1. There is sex. On the other hand, if a switch that flows through the abnormality determination circuit 50 is provided, it is only necessary to turn on the switch for a moment to check the wear of the brushes 5a, 5b, and 5c. Can be minimized.

Embodiment 6 FIG.
Next, a brush abnormality detection apparatus for a rotary electric machine according to Embodiment 6 of the present invention will be described.
The brush abnormality detection apparatus for a rotating electrical machine according to Embodiment 6 of the present invention detects the wear of the brush depending on whether light passes through an optical fiber provided on the brush.
As shown in FIG. 8, the rotating shaft 2 is provided with three slip rings 4a, 4b, 4c, and brushes 5a, 5b, 5c are provided so as to be in contact with the slip rings 4a, 4b, 4c, respectively. Yes. Optical fibers 60a, 60b, and 60c are provided in the brushes 5a, 5b, and 5c, respectively. The optical fibers 60a, 60b, and 60c are connected in series in this order. A light emitting unit 61 that emits light is provided at the end of the optical fiber 60a, and a light receiving unit 62 that receives light transmitted through the optical fiber 60c is provided at the end of the optical fiber 60c. The light emitting unit 61 and the light receiving unit 62 are each electrically connected to the ECU 13, and the alarm device 14 is further electrically connected to the ECU 13.

  When the brush 5a is worn due to friction between the brush 5a and the slip ring 4a and the height of the brush 5a is reduced, the optical fiber 60a provided inside the brush 5a gradually approaches the slip ring 4a. Eventually, the optical fiber 60a comes into contact with the slip ring 4a, the optical fiber 60a and the slip ring 4a rub against each other, and the optical fiber 60a is broken. Before the optical fiber 60a is destroyed, the light emitted from the light emitting unit 61 is sequentially transmitted through the optical fibers 60a, 60b, and 60c. The light receiving unit 62 receives the light, and a signal indicating that the light receiving unit 62 has received the light. It is transmitted to the ECU 13. In this case, the ECU 13 determines that none of the brushes 5a, 5b, 5c is worn. On the other hand, when the optical fiber 60a is destroyed as described above, the light emitted from the light emitting unit 61 does not reach the light receiving unit 62, and thus a signal indicating that the light receiving unit 62 did not receive the light is transmitted to the ECU 13. Then, the ECU 13 determines that any of the brushes 5a, 5b, 5c is worn and activates the alarm device 14. When the brushes 5b and 5c are worn, the wear is determined by the same operation.

  In this way, the optical fibers 60a, 60b, 60c are fixed to the brushes 5a, 5b, 5c, the brushes 5a, 5b, 5c are worn, and the optical fibers 60a, 60b, 60c are destroyed by the slip rings 4a, 4b, 4c. Thus, when the light receiving unit 62 no longer detects the light transmitted through the optical fibers 60a, 60b, and 60c, the wear of the brushes 5a, 5b, and 5c is detected. Therefore, an electric circuit is used to detect the wear of the brushes 5a, 5b, and 5c. Therefore, it is possible to eliminate the influence of electromagnetic noise of the existing electric circuit. As a result, the wear detection accuracy of the brushes 5a, 5b, 5c can be improved.

  In the sixth embodiment, the optical fibers 60a, 60b, and 60c are fixed inside the brushes 5a, 5b, and 5c. However, the present invention is not limited to this configuration. Even if the brushes 5a, 5b, and 5c are fixed to the side surfaces, the brushes 5a, 5b, and 5c are worn and the optical fibers 60a, 60b, and 60c and the slip rings 4a, 4b, and 4c are rubbed together, so that the optical fibers 60a, 60b, and 60c are It only needs to be destroyed.

  In the sixth embodiment, the optical fibers 60a, 60b, and 60c are connected in series. However, the present invention is not limited to this embodiment. The light emitting unit 61 may be provided at one end of each of the optical fibers 60a, 60b, and 60c, and the light receiving unit 62 may be provided at the other end. In this case, it can be specified which of the brushes 5a, 5b, 5c is worn.

  In Embodiment 1-6, although the three-phase alternating current motor was used, it is not limited to this. A single-phase AC motor may be used. Further, the number of brushes is not limited to three, and may be one, two, or four or more.

  DESCRIPTION OF SYMBOLS 1 Motor (rotary electric machine), 2 Rotating shaft, 4, 4a, 4b, 4c Slip ring (fixed contact, wear detection contact), 5a, 5b, 5c Brush, 5a2 (Brush 5a) side surface (surface), 7a, 7b, 7c, 37, 47 Moving contact (wear detection contact), 8 Inverter, 9 Battery, 10 Switch, 11, 12 Ammeter, 13 ECU (Abnormality judging means), 21 (Brush) first part (moving) Contact, contact for wear detection), 38, 48 fixed contact (contact for wear detection), 40 notch, 41 spring (elastic member), 42 abutment member, 50 abnormality determination circuit, 51 power supply, 52 ammeter, 60a, 60b, 60c Optical fiber, 61 Light emitting part, 62 Light receiving part, S1-S6 Switching element.

Claims (10)

A brush abnormality detection device for a rotating electrical machine,
At least one slip ring provided to rotate together with the rotating shaft of the rotating electrical machine;
At least one brush provided in contact with the slip ring;
A battery for supplying electric power to the rotating electrical machine via the brush;
An inverter provided between the battery and the brush and having a plurality of switching elements;
At least one ammeter for detecting a current flowing through any of the plurality of switching elements;
Based on the state of wear of the brush, a contact for wear detection that electrically connects the battery and the switching element capable of detecting current with the ammeter through the brush;
A switch provided between the battery and the wear detection contact;
An abnormality determination means,
The abnormality determining means detects the wear of the brush when the ammeter detects current when the switch and the switching element capable of detecting current with the ammeter are turned on. Brush abnormality detection device. The contact for wear detection is
A fixed contact;
The brush abnormality detection device for a rotating electrical machine according to claim 1, further comprising a moving contact that is fixed to the brush and moves toward the fixed contact as the brush is worn.   The brush abnormality detection device for a rotating electrical machine according to claim 2, wherein the fixed contact is the slip ring. The brush,
A first portion electrically connected to the switch;
An insulator is provided on the brush so as to be separated from the second portion in contact with the slip ring,
4. The rotating electrical machine according to claim 3, wherein the moving contact is the first portion, and when the brush is worn, the insulator is broken by the slip ring and the first portion contacts the slip ring. Brush abnormality detection device. The contact for wear detection is
A fixed contact fixed to the brush;
A moving contact that moves toward the fixed contact with wear of the brush,
The brush is provided with a notch that is recessed with respect to its surface,
The moving contact is fixed to an abutting member pressed against the surface by an elastic member,
The brush abnormality detection device for a rotating electrical machine according to claim 1, wherein the moving contact contacts the fixed contact when the brush is worn and the contact member enters the notch. A plurality of the brushes;
The brush abnormality detection device for a rotating electrical machine according to any one of claims 1 to 5, wherein the wear detection contact of each brush is provided in parallel between the switch and the inverter. A brush abnormality detection device for a rotating electrical machine,
At least one slip ring provided to rotate together with the rotating shaft of the rotating electrical machine;
At least one brush provided in contact with the slip ring;
An abnormality determination circuit including a power source and an ammeter;
A contact for wear detection provided in the abnormality determination circuit and connected based on a wear state of the brush;
An abnormality determination means,
The contact for wear detection is
A fixed contact;
A moving contact that moves toward the fixed contact with wear of the brush,
The brush is provided with a notch that is recessed with respect to its surface,
The moving contact is fixed to an abutting member pressed against the surface by an elastic member,
The abnormality determination unit is configured to detect the current when the ammeter detects a current when the moving contact comes into contact with the fixed contact due to wear of the brush and the contact member entering the notch. A brush abnormality detection device for rotating electrical machines that detects wear. A plurality of the brushes;
The brush abnormality detection device for a rotating electrical machine according to claim 7, wherein the wear detection contact of each brush is provided in parallel in one of the abnormality determination circuits. A brush abnormality detection device for a rotating electrical machine,
At least one slip ring provided to rotate together with the rotating shaft of the rotating electrical machine;
At least one brush provided in contact with the slip ring;
An optical fiber fixed to the brush;
A light emitting unit for making light incident on the optical fiber;
A light receiving portion for receiving light transmitted through the optical fiber;
An abnormality determination means,
The abnormality determining means detects the wear of the brush when the brush is worn and the optical fiber is broken by the slip ring, so that the light receiving unit no longer detects the light transmitted through the optical fiber. Electric brush abnormality detection device. A plurality of the brushes;
The brush abnormality detection device for a rotating electrical machine according to claim 9, wherein the optical fibers fixed to the brushes are connected in series.

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