JP2017034741A - Rectification device and rotary electric machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rectification device capable of preventing dielectric breakdown further than the prior arts while suppressing a physical constitution small, and a rotary electric machine.SOLUTION: In a rectification device 20, a pair of brushes 23 (namely, a positive pole brush 23a and a negative pole brush 23b) are connected with a power source E, and a pair of rectification brushes 21 (namely, rectification brushes 21a and 21b) are disposed at a rear side of the brushes 23 in a rotation direction AR of a rectifier 22. The rectification device comprises diodes D that are connected mutually between the pair of rectification brushes 21. In such a configuration, the number of diodes D can be reduced, and the number of conducting lines may also be reduced. Therefore, a physical constitution of the rectification device 20 can be suppressed small. A rectifier piece 22a may become a voltage that is changed just by a voltage drop of the diode D electrically connected mutually between the pair of rectification brushes 21a and 21b, and a potential difference from the power source is made less than a dielectric breakdown voltage. Thus, the dielectric breakdown may be prevented further than the prior arts.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a rectifier having a commutator, a brush, and a rectifier brush, and a rotating electrical machine including the rectifier.

  Conventionally, an example of a technique related to a rectifier of a brushed motor intended to prevent sparks with a simple structure has been disclosed (see, for example, Patent Document 1). Spark is synonymous with electric discharge and is a dielectric breakdown that occurs continuously in the gas between the electrodes. In the rectifier of Patent Document 1, the commutator has a plurality of segments, the plurality of segments have a main brush portion and an auxiliary brush portion, and an insulating layer is bonded between the main brush portion and the auxiliary brush portion, The auxiliary brush portion maintains contact with the segment for a predetermined period after the segment leaves the main brush portion. The pair of auxiliary brush portions are individually electrically connected to both ends of the battery through two diodes for power regeneration. The pair of auxiliary brush portions are connected by a capacitor.

JP 2011-004582 A

  However, the rectifier of Patent Document 1 requires two diodes to be electrically connected between the pair of auxiliary brush portions and the battery. Assuming that the size of the diode is constant, as the number of diodes increases, the space for accommodating the diodes increases and the number of conductive lines for electrically connecting the diodes also increases. Therefore, there exists a problem that the physique of a rectifier must be enlarged.

  Further, the capacitor connected between the pair of auxiliary brush portions needs to have a large capacity in order to suppress the potential change of the auxiliary brush portion. As the capacity increases, the physique of the capacitor also increases, so that there is a problem that the rectification apparatus must be increased in size.

  On the other hand, dielectric breakdown occurs between the commutator and the brush when a required voltage (that is, a potential difference) is applied. Hereinafter, the voltage at which dielectric breakdown occurs between the commutator and the brush is referred to as “dielectric breakdown voltage”. Since the brushes (for example, the main brush part and the auxiliary brush part) are electrically connected to the battery directly or indirectly, the supply voltage of the battery (that is, the potential difference between the plus terminal and the minus terminal) affects.

  The supply voltage of the battery may exceed the rated voltage due to factors such as overcharging and replacement with a new one. The sum of the supply voltage applied to the brush exceeding the rated voltage and the back electromotive force generated in the commutator immediately after leaving the brush tends to exceed the dielectric breakdown voltage. In the rectifier of Patent Document 1, since both the main brush portion and the auxiliary brush portion are electrically connected to the battery, there are cases where the potential fluctuation of the auxiliary brush portion cannot be absorbed depending on the capacitance of the capacitor. In this case, since the sum of the supply voltage and the counter electromotive force exceeds the dielectric breakdown voltage, there is a problem that a spark may occur.

  This invention is made | formed in view of such a point, and it aims at providing the rectifier and rotary electric machine which can prevent a dielectric breakdown conventionally, while suppressing a physique small.

  A first invention made to solve the above-mentioned problems is that a plurality of commutator pieces (22a, 22a, 22a, 22b, 22e, 22g), a pair of brushes (23) in contact with the commutator, and a pair of brushes (21, 21a, 21b) in contact with the commutator. In the rectifying device (20), the pair of brushes are electrically connected to the power source (E) directly or indirectly, and the rectifying brush is connected to the rotation direction (AR) of the commutator. A diode (D, D1, D2) disposed on the rear side of the brush and electrically connected between the pair of rectifying brushes is provided.

  According to this configuration, the pair of brushes are electrically connected to the power source. Although a diode is electrically connected between the pair of rectifying brushes, the rectifying brush is not electrically connected to a power source. Since one diode may be electrically connected between the pair of rectifying brushes, the number of diodes can be reduced, and further the number of conductive lines can be reduced. Therefore, the physique of the rectifier can be reduced.

  Further, since the commutator piece immediately after the brush is separated comes into contact with one side of the pair of rectifying brushes, the voltage changes by the voltage drop of the diode electrically connected between the pair of rectifying brushes. . Since the potential difference between the voltage of the commutator piece and the voltage of the power supply is less than the dielectric breakdown voltage, it is possible to prevent dielectric breakdown as compared with the conventional case.

  According to a second aspect of the present invention, in the rotating electrical machine (10), the rectifying device (20) according to any one of claims 1 to 7, the rotating shaft (11) provided with the commutator, and the rotating shaft It has a rotor (13) fixed directly or indirectly, and a stator (14) provided via the rotor and a gap (G).

  According to this configuration, it is possible to provide a rotating electrical machine that can prevent a dielectric breakdown more than the conventional one while suppressing the physique to be small.

  Note that the number of phases of the winding including the coil is arbitrary as long as it is three or more phases. The “power source” may be a power source (for example, a battery or a commercial power source) itself, and may further include a power conversion device that converts and outputs power. The “rotary electric machine” is arbitrary as long as it is a device having a rotating member (for example, a shaft or a shaft). For example, a generator, a motor, a motor generator, and the like are applicable. The generator includes a case where the motor generator is a power generation function machine, and the motor includes a case where the motor generator is a motor. The “rotor” is formed into a circular shape (including an annular shape and a cylindrical shape).

It is a partial cross section figure which shows typically the structural example of a rotary electric machine. It is a perspective view which shows typically the structural example of a rectifier. It is a circuit diagram which shows typically the structural example of a rectifier. It is a circumferential direction developed view showing a first arrangement example of a brush, a rectifying brush, and a commutator piece. It is a time chart figure which shows the voltage change of the commutator piece in the example of the 1st arrangement. It is the circumferential direction expanded view which shows the 2nd example of arrangement | positioning of a brush, a commutation brush, and a commutator piece. It is a time chart figure showing voltage change of a commutator piece in the 2nd example of arrangement. It is a circumferential direction expanded view which shows the 3rd example of arrangement | positioning of a brush, a commutation brush, and a commutator piece. It is a circumferential direction expanded view which shows the 4th example of arrangement | positioning of a brush, a commutation brush, and a commutator piece. It is a circumferential direction developed view which shows the 5th example of arrangement | positioning of a brush, a commutation brush, and a commutator piece. It is a circumferential direction expanded view which shows the 6th example of arrangement | positioning of a brush, a commutation brush, and a commutator piece.

  Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings. Note that unless otherwise specified, “connecting” means electrically connecting. Each figure shows elements necessary for explaining the present invention, and does not necessarily show all actual elements. When referring to directions such as up, down, left and right, the description in the drawings is used as a reference.

  Alphanumeric continuous codes are abbreviated using the symbol “˜”. For example, “coils L1 to L6” means “coils L1, L2, L3, L4, L5, L6”. The alphabetic character of the sign means different elements in upper case and lower case. For example, the commutator 22A and the commutator piece 22a shown in FIG. 4 are separate elements. The fixing method between members is not ask | required. The magnetic material is mainly a soft magnetic material, but any material or configuration may be used as long as the magnetic flux flows.

[Embodiment 1]
The first embodiment will be described with reference to FIGS. The rotating electrical machine 10 shown in FIG. 1 is an example of an inner rotor type. The rotating electrical machine 10 includes a rotating shaft 11, a rotor 13, a stator 14, a rectifier 20, and the like in a housing 12.

  The housing 12 is also called a “frame” or “housing”, and may be formed in an arbitrary shape as long as it can accommodate the above-described elements. Although not shown, one or more of a pulley, a rotation angle detection sensor, a semiconductor element, and the like may be accommodated.

  The rotating shaft 11, also called “shaft”, is rotatably supported by the housing 12 via a bearing (not shown). The rotor 13 is fixed to the rotating shaft 11 directly or indirectly. That is, the rotating shaft 11 and the rotor 13 rotate integrally. The rotor 13 includes a winding 13a, a rotor core 13b, and the like. The winding 13a is a winding of three or more phases and is wound around the rotor core 13b. The rotor core 13b is mainly formed of a magnetic material.

  The stator 14 is fixed to the housing 12. The configuration of the stator 14 is arbitrary, and a plurality of magnets may be included. For example, the radial end face facing the rotor 13 is arranged in the circumferential direction so that the polarities of the N pole and the S pole are alternate. A gap G is provided between the stator 14 and the rotor 13 in the radial direction Ra.

  The rectifier 20 includes a pair of or more rectifying brushes 21, a commutator 22, a pair of or more brushes 23, a diode D, and the like. The rectifying brush 21 and the brush 23 are accommodated in insulating brush holders (not shown). The brush holder is provided in the housing 12 and is urged by an elastic member (for example, a spring or rubber) such that the rectifying brush 21 and the brush 23 are in contact with the commutator 22. The commutator 22 is provided on the rotating shaft 11 as shown in FIG. A configuration example of the commutator 22 will be described later (see FIGS. 2 and 3).

  The pair of rectifying brushes 21 corresponds to, for example, a rectifying brush 21a and a rectifying brush 21b. A diode D is connected between the rectifying brush 21a and the rectifying brush 21b so that the tip end side in the rotation direction AR (that is, the rectifying brush 21a side) is a cathode. The pair of brushes 23 corresponds to, for example, a positive brush 23a and a negative brush 23b. The positive brush 23 a is connected to the positive terminal of the power source E, and the negative brush 23 b is connected to the negative terminal of the power source E. The power source E is arbitrary as long as it can supply power for operating the rotating electrical machine 10 (that is, rotating, stopping, etc.), and for example, a secondary battery, a fuel cell, a solar cell, and the like are applicable. In order to charge the electric power generated by the rotating electrical machine 10 by a regenerative brake or the like, a secondary battery is desirable.

  A power converter INV indicated by a two-dot chain line may be interposed between the rotating electrical machine 10 (specifically, the brush 23) and the power source E. The power converter INV performs control for converting the power supplied from the power source E and outputting it to the rotating electrical machine 10 by, for example, PWM (Pulse Width Modulation). The power conversion device INV corresponds to, for example, an ECU (Electronic Control Unit) or a computer. The rotational speed and torque of the rotating shaft 11 can be controlled by power conversion control performed by the power converter INV.

  The commutator 22 shown in FIG. 2 is fixed to the rotating shaft 11 that rotates in the rotation direction AR. This commutator 22 has a plurality of commutator pieces 22a provided side by side in the circumferential direction Ci as shown in the figure. The number of commutator pieces 22a constituting the commutator 22 may be arbitrarily set, and FIG. 3 shows an example in which six commutator pieces 22a are set. Insulation is ensured between the commutator pieces 22a adjacent to each other in the circumferential direction Ci. For example, as shown in FIG. 3, a gap may be provided between the commutator pieces 22a, or the space between the commutator pieces 22a may be filled with an insulating member.

  The pair of rectifying brushes 21 are disposed on the rear side of the pair of brushes 23 with respect to the rotation direction AR (right rotation in FIG. 2) of the commutator 22A. That is, the rectifying brush 21a is arranged on the rear side (left side in FIG. 2) of the corresponding positive electrode brush 23a with respect to the rotation direction AR of the commutator 22A. Similarly, the rectifying brush 21b is disposed on the rear side (left side in FIG. 2) of the corresponding negative electrode brush 23b with respect to the rotation direction AR of the commutator 22A.

  Further, the commutator pieces 22a adjacent to each other in the circumferential direction Ci are connected to each other by a winding 13a indicated by a one-dot chain line in FIG. The number of coils included in the winding 13a may be arbitrarily set, and FIG. 3 shows an example in which six coils L1 to L6 are set. The coils L1 to L6 are connected between the commutator pieces 22a adjacent to each other in the circumferential direction Ci. In FIG. 3, illustration of the power conversion device INV, the rotating shaft 11 and the like shown in FIG. 1 is omitted.

  The rectifying action by the rectifying device 20 described above will be described with reference to FIGS. An example in which the positive electrode brush 23a is separated from the commutator piece 22a is shown in FIGS. 4 and 5, and an example in which the negative electrode brush 23b is separated from the commutator piece 22a is shown in FIGS. For convenience of explanation, in FIGS. 4 and 6, the commutator piece 22 a that is away from the positive electrode brush 23 a and the negative electrode brush 23 b that are in contact with each other is hatched and the coil L <b> 6 is not shown. The diode D1 shown in FIGS. 4 and 6 corresponds to the diode D shown in FIGS.

  The commutator piece 22a with hatched lines is hereinafter referred to as “detaching commutator piece 22ax” for convenience. The potential of the negative terminal of the power source E shown in FIGS. 1 and 3 is set as a reference (hereinafter simply referred to as “reference potential”), and is shown as 0 [V] in FIGS. However, the reference potential is not necessarily the same as the ground potential (so-called ground). Therefore, the commutator piece voltage V22a of the separation commutator piece 22ax is a potential difference from the reference potential. Strictly speaking, voltage drops occur due to the resistances of the brush, the rectifying brush, and the conductive wire, but these factors are not different from the conventional ones, and thus are not considered below. The conductive line corresponds to a “connection line” for connecting elements, and includes a case where a part of the winding is used.

  In FIG. 4, when the positive electrode brush 23a moves away from the separation commutator piece 22ax, arc discharge A1 (that is, dielectric breakdown) indicated by an arrow may occur due to the counter electromotive force generated in the coil L2. That is, the dielectric breakdown voltage Vth is generated between the positive electrode brush 23a and the separation commutator piece 22ax. The commutator piece voltage V22a changes as shown in FIG. 5, for example.

  In FIG. 5, the commutator piece voltage V22a is the same as the power supply voltage Ve (that is, the potential of the positive terminal of the power source E) until time t11 when the separation commutator piece 22ax is in contact with the positive electrode brush 23a. When the separation commutator piece 22ax is separated from the positive electrode brush 23a, a back electromotive force is generated by the coil L2, and the voltage V13 (however, V13 <0) indicated by a two-dot chain line can be obtained. The voltage V13 falls below 0 [V] in addition to the counter electromotive force generated by the coil L2, in addition to the negative terminal of the power source E via the rectifying brush 21a, the diode D1, the rectifying brush 21b, the commutator piece 22a, and the negative brush 23b. This is because it is connected to (that is, 0 [V] of the reference potential). When the voltage V15, which is the potential difference between the power supply voltage Ve and the voltage V13, is equal to or higher than the dielectric breakdown voltage Vth (V15 ≧ Vth), arc discharge A1 occurs.

  Here, the separation commutator piece 22ax when separated from the positive electrode brush 23a is the negative terminal of the power source E via the commutation brush 21a, the diode D1, the commutation brush 21b, the commutator piece 22a, and the negative electrode brush 23b as described above. Connected to. That is, the commutator piece voltage V22a becomes a voltage V12 (for example, −0.7 [V]) lower than 0 [V] (that is, the reference potential) by the voltage drop of the diode D1. The voltage V12 is also the cathode side voltage of the diode D1. Therefore, the voltage V14, which is the potential difference between the power supply voltage Ve and the voltage V12, is less than the dielectric breakdown voltage Vth (V14 <Vth), and the occurrence of arc discharge A1 can be suppressed. Since the voltage V12 is maintained regardless of the fluctuation of the power supply voltage Ve, it is possible to suppress a situation where the voltage V14 becomes equal to or higher than the dielectric breakdown voltage Vth.

  Thereafter, at time t12 when the back electromotive force generated by the coil L2 is settled, the commutator piece voltage V22a becomes the voltage V11. Voltage V11 is a partial pressure applied to coil L2 in coils L1 to L6 shown in FIG. At the time t13 when the commutator 22 fixed to the rotating shaft 11 makes one rotation and the separation commutator piece 22ax comes into contact with the positive electrode brush 23a again, it becomes the same as the power supply voltage Ve.

  In FIG. 6, when the negative electrode brush 23b is separated from the separation commutator piece 22ax, there is a possibility that arc discharge A2 (that is, dielectric breakdown) indicated by an arrow may occur due to the counter electromotive force generated in the coil L4. That is, the dielectric breakdown voltage Vth is generated between the negative brush 23b and the separation commutator piece 22ax. The commutator piece voltage V22a changes as shown in FIG. 7, for example.

  In FIG. 7, the commutator piece voltage V22a is the same as 0 [V] (that is, the reference potential) until time t21 when the separation commutator piece 22ax is in contact with the negative electrode brush 23b. When the separation commutator piece 22ax is separated from the negative electrode brush 23b, a counter electromotive force is generated by the coil L4, and the voltage V21 (where V21> Ve) indicated by a two-dot chain line can be obtained. The voltage V21 exceeds the power supply voltage Ve because, in addition to the back electromotive force generated by the coil L4, the separation commutator piece 22ax is powered via the rectifying brush 21b, the diode D1, the rectifying brush 21a, the commutator piece 22a, and the positive brush 23a. This is because it is connected to the positive terminal of the source E. When the voltage V25, which is the potential difference between 0 [V] and the voltage V21, is equal to or higher than the dielectric breakdown voltage Vth (V25 ≧ Vth), arc discharge A2 occurs.

  Here, the separation commutator piece 22ax when separated from the negative electrode brush 23b is a positive terminal of the power source E via the commutation brush 21b, the diode D1, the commutation brush 21a, the commutator piece 22a, and the positive electrode brush 23a as described above. Connected to. That is, the commutator piece voltage V22a becomes a voltage V22 (for example, 12.7 [V]) that is higher than the power supply voltage Ve (that is, the potential of the positive terminal of the power source E) by the voltage drop of the diode D1. The voltage V22 is also the cathode side voltage of the diode D1. Therefore, the voltage V24, which is the potential difference between 0 [V] and the voltage V22, is less than the dielectric breakdown voltage Vth (V24 <Vth), and the occurrence of arc discharge A2 can be suppressed. Since the voltage V22 is maintained regardless of the fluctuation of the power supply voltage Ve, it is possible to suppress the situation where the voltage V24 becomes equal to or higher than the dielectric breakdown voltage Vth.

  Thereafter, at time t22 when the back electromotive force generated by the coil L4 is settled, the commutator piece voltage V22a becomes the voltage V23. Voltage V23 is a partial pressure applied to coil L4 in coils L1 to L6 shown in FIG. At time t23 when the commutator 22 fixed to the rotating shaft 11 makes one rotation and the separation commutator piece 22ax comes into contact with the negative electrode brush 23b again, it becomes the same as 0 [V].

  According to the first embodiment described above, the following operational effects can be obtained.

  (1) In the rectifier 20, the pair of brushes 23 (that is, the positive brush 23a and the negative brush 23b) are connected to the power source E, and the pair of rectifier brushes 21 (that is, the rectifier brushes 21a and 21b) are rotating directions of the commutator 22A. It was set as the structure provided with the diode D1 arrange | positioned on the back side of the brush 23 with respect to AR, and connected between a pair of rectifying brushes 21 (refer FIGS. 1-4, FIG. 6). According to this configuration, the pair of brushes 23 are connected to the power source E. Although the diode D <b> 1 is connected between the pair of rectifying brushes 21, the rectifying brush 21 is not connected to the power source E. Since one diode D1 may be connected between the pair of rectifying brushes 21, the number of diodes D1 can be reduced, and the number of conductive lines can be reduced. Therefore, the physique of the rectifier 20 can be suppressed small. Although not shown, two or more pairs of brushes 23 may be connected to the power source E. In this case, the same effect can be obtained.

  Further, the commutator piece 22a (that is, the separation commutator piece 22ax) immediately after the brush 23 is separated comes into contact with one side of the commutating brush 21 forming a pair (the commutating brush 21a in FIG. 4 and the commutating brush 21b in FIG. 6). Therefore, the voltages V12 and V22 change by the voltage drop of the diode D1 electrically connected between the pair of rectifying brushes 21a and 21b. The potential difference between the voltages V12 and V22 of the commutator piece 22a and the power supply voltage Ve of the power source E is less than the dielectric breakdown voltage Vth (see FIGS. 5 and 7). In this way, the voltages V12 and V22, which are the cathode side voltages of the diode D1, are increased, and it is possible to prevent dielectric breakdown as compared with the conventional case.

  (8) The rotating electrical machine 10 includes a rectifier 20, a rotating shaft 11 provided with a commutator 22 </ b> A, a rotor 13 fixed directly or indirectly to the rotating shaft 11, the rotor 13 and the gap G. And a stator 14 provided (see FIG. 1). According to this configuration, it is possible to provide the rotating electrical machine 10 that can prevent the dielectric breakdown more than the conventional one while suppressing the physique to be small.

  (9) The rotor 13 of the rotating electrical machine 10 is provided with a winding 13a including coils L1 to L6 (see FIGS. 1 and 3). According to this configuration, the rotating electrical machine 10 having the rotor 13 provided with the winding 13a can be provided with the rotating electrical machine 10 capable of preventing dielectric breakdown as compared with the related art while suppressing the physique to be small.

[Embodiment 2]
The second embodiment will be described with reference to FIG. For simplicity of illustration and description, unless otherwise specified, the same elements as those used in the first embodiment are denoted by the same reference numerals and description thereof is omitted. Therefore, the points different from the first embodiment will be mainly described.

  FIG. 8 shows an example of the commutator 22 and a commutator 22B that is a modification of the commutator 22A. The commutator 22B has a plurality of commutator pieces 22b, like the commutator 22A. The commutator 22B is different from the commutator 22A in the shape of the outer peripheral surface of each commutator piece 22b.

  Each commutator piece 22b of the commutator 22B has a first contact part 22d and a second contact part 22c. 22 d of 1st contact parts are the parts which contact brush 23 (namely, positive electrode brush 23a and negative electrode brush 23b), and let the width | variety of the circumferential direction Ci be the 1st contact width W1. The second contact portion 22c is a portion that contacts the rectifying brush 21, and the width in the circumferential direction Ci is defined as a second contact width W2. The second contact width W2 may be set differently from the first contact width W1, and the second contact width W2 may be set smaller than the first contact width W1 as shown in the figure (W2 <W1).

  The rectifying brush 21 (that is, the rectifying brushes 21a and 21b) is formed in a shape that avoids contact with the plurality of commutator pieces 22b at the same time. In the configuration example of FIG. 8, when the width of the rectifying brushes 21a and 21b in the circumferential direction Ci is the circumferential width WR and the interval between the second contact portions 22c adjacent to the circumferential direction Ci is the mutual width WM, the circumferential width WR is set smaller than the mutual width WM (WR <WM).

  The rectifying brush 21a is disposed on the rear side (left side in FIG. 8) of the corresponding positive electrode brush 23a with respect to the rotation direction AR of the commutator 22B. The front end face of the rectifying brush 21a and the rear end face of the positive brush 23a may be aligned with the boundary line B1 shown in the drawing.

  The rectifying brush 21b is disposed on the rear side (left side in FIG. 8) of the corresponding negative electrode brush 23b with respect to the rotation direction AR of the commutator 22B. The front end face of the rectifying brush 21c and the rear end face of the negative brush 23b may be aligned with the boundary line B2 shown in the drawing.

  The positions of the brush 23 (that is, the positive brush 23a and the negative brush 23b) and the rectifying brush 21 (that is, the rectifying brushes 21a and 21b) shown in FIG. 8 are different from those of the first embodiment (see FIGS. 4 and 6). That is, the brush 23 and the rectifying brush 21 are arranged with their positions shifted in the axial direction Ax. In other words, the brush 23 contacts only the first contact part 22d of the commutator piece 22b, and the commutation brush 21 contacts only the second contact part 22c of the commutator piece 22b.

  Also in the configuration described above, when the positive electrode brush 23a is separated from the first contact portion 22d (the commutator piece 22b corresponding to the separation commutator piece 22ax), the potential changes as shown in FIG. When the negative electrode brush 23b is separated from the electric potential, the potential changes as shown in FIG.

  According to the second embodiment described above, the following functions and effects can be obtained in addition to the functions and effects shown in the first embodiment.

  (2) The rectifying brush 21 (that is, the rectifying brushes 21a and 21b) and the brush 23 (that is, the positive electrode brush 23a and the negative electrode brush 23b) are arranged so as to be shifted in the axial direction Ax (see FIG. 8). According to this structure, since the rectifying brush 21 can design a shape, a magnitude | size, etc. irrespective of the brush 23, the freedom degree of design increases.

  (3) The commutator piece 22b is configured such that the first contact width W1 in the circumferential direction Ci that contacts the brush 23 and the second contact width W2 in the circumferential direction Ci that contacts the rectifying brush 21 are different. (See FIG. 8). According to this structure, the timing which contacts the brush 23 and the timing which contacts the rectifying brush 21 can be designed finely. Therefore, the degree of freedom in design is increased, the occurrence of short-circuit current can be reliably prevented, and arc discharges A1 and A2 (see FIGS. 4 and 6) due to dielectric breakdown can be suppressed.

  (4) The rectifying brushes 21a and 21b are each configured to have a shape that avoids contact with the plurality of commutator pieces 22b (specifically, the second contact portion 22c) at the same time (see FIG. 8). . According to this configuration, since the rectifying brush 21 does not contact with the plurality of commutator pieces 22b at the same time, it is possible to reliably prevent the occurrence of a short-circuit current.

  (5) The commutator 22B has a first contact portion 22d that contacts the brush 23 and a second contact portion 22c that contacts the rectifying brush 21, and the circumferential width WR of the rectifying brush 21 is adjacent to the circumferential direction Ci. It was set as the structure set smaller than the mutual width WM of the 2 contact site | part 22c (WR <WM; refer FIG. 8). According to this configuration, since the circumferential width WR is smaller than the mutual width WM, the rectifying brush 21 does not contact with the plurality of commutator pieces 22b (specifically, the second contact portions 22c) at the same time. Therefore, generation | occurrence | production of a short circuit current can be prevented further reliably.

[Embodiment 3]
The third embodiment will be described with reference to FIG. For simplicity of illustration and description, unless otherwise specified, the same elements as those used in the first and second embodiments are denoted by the same reference numerals and description thereof is omitted. Therefore, the difference from Embodiments 1 and 2 will be mainly described.

  FIG. 9 shows an example of the commutator 22 and a commutator 22C that is a modification of the commutator 22A. The commutator 22C includes a plurality of commutator pieces 22e, a plurality of independent commutator pieces 22f, and the like. The number of commutator pieces 22e and the number of independent commutator pieces 22f may both be set arbitrarily. In this embodiment, the number of commutator pieces 22e matches the number of independent commutator pieces 22f.

  Like the commutator piece 22b shown in FIG. 8, the commutator piece 22e has a first contact portion 22d and a second contact portion 22c. The shape of the commutator piece 22e is different from that of the commutator piece 22b shown in FIG. 8, and is formed into an L shape, for example. In the commutator piece 22e, the width in the circumferential direction Ci applied to the first contact part 22d is defined as a first contact width W3, and the width in the circumferential direction Ci applied to the second contact part 22c is defined as a second contact width W4. The second contact width W4 may be set differently from the first contact width W3, and the second contact width W4 may be set smaller than the first contact width W3 as shown in the figure (W4 <W3).

  The independent commutator piece 22f is disposed at a position corresponding to the second contact portion 22c of the commutator piece 22e, and is not connected to other elements including the winding 13a. Therefore, the independent commutator piece 22f becomes a floating potential when it does not contact the rectifying brushes 21a and 21b.

  Even in the configuration described above, when the positive electrode brush 23a moves away from the first contact portion 22d (the commutator piece 22e corresponding to the separation commutator piece 22ax), the potential changes as shown in FIG. When the negative electrode brush 23b is separated from the electric potential, the potential changes as shown in FIG.

  According to the third embodiment described above, the following functions and effects can be obtained in addition to the functions and effects shown in the first and second embodiments.

  (6) The commutator 22C includes an independent commutator piece 22f that has a floating potential when it does not contact the commutating brush 21 (see FIG. 9). According to this configuration, since the independent commutator piece 22f is not connected to the winding 13a, the floating potential state is maintained when it does not contact the brush 23 or the rectifying brush 21. Therefore, it does not exceed the dielectric breakdown voltage Vth between the brush 23 and the rectifying brush 21, and furthermore, arc discharges A1 and A2 (see FIGS. 4 and 6) due to dielectric breakdown can be suppressed.

[Embodiment 4]
The fourth embodiment is a modification of the second embodiment (see FIG. 8), and will be described with reference to FIG. For simplicity of illustration and description, unless otherwise specified, the same elements as those used in the first to third embodiments are denoted by the same reference numerals and description thereof is omitted. Therefore, it demonstrates centering on the point which is different from Embodiment 1-3.

  The configuration shown in FIG. 10 is different from the configuration shown in FIG. 8 in that it further includes rectifying brushes 21c and 21d and a diode D2. The rectifying brushes 21c and 21d correspond to a pair of rectifying brushes 21 in the same manner as the rectifying brushes 21a and 21b. The rectifying brushes 21a to 21d are arranged so as to be displaced from the brush 23 in the axial direction Ax. The forward rotation direction AR1 shown in FIG. 10 corresponds to the rotation direction AR shown in FIG. The reverse rotation direction AR2 is the reverse direction to the normal rotation direction AR1.

  The rectifying brush 21c is disposed on the rear side (right side in FIG. 10) of the corresponding positive electrode brush 23a with respect to the reverse rotation direction AR2 of the commutator 22B. The front end face of the rectifying brush 21c and the rear end face of the positive brush 23a may be aligned with the boundary line B3 shown in the drawing.

  The rectifying brush 21d is disposed on the rear side (right side in FIG. 10) of the corresponding negative electrode brush 23b with respect to the reverse rotation direction AR2 of the commutator 22B. The front end face of the rectifying brush 21d and the rear end face of the negative brush 23b may be aligned with the boundary line B4 shown in the drawing.

  When the width in the circumferential direction Ci of the rectifying brushes 21c and 21d is defined as the circumferential width WR, and the interval between the second contact portions 22c adjacent in the circumferential direction Ci is defined as the mutual width WM, the circumferential width WR is greater than the mutual width WM. Is set smaller (WR <WM).

  The diode D2 corresponds to the diode D shown in FIGS. The diode D2 is connected between the rectifying brush 21c and the rectifying brush 21d so that the tip end side in the rotation direction AR2 (that is, the rectifying brush 21d side) is a cathode. In other words, the diodes D1 and D2 are connected so as to be opposite to each other as illustrated.

  When the commutator 22B rotates in the positive rotation direction AR1 with the rotation of the rotating shaft 11, the rectifying brushes 21a and 21b and the diode D1 are used as in the second embodiment. In this case, when the positive electrode brush 23a is separated from the first contact portion 22d (the commutator piece 22b corresponding to the separation commutator piece 22ax), the potential changes as shown in FIG. When the brush 23b leaves, the potential changes as shown in FIG.

  When the commutator 22B rotates in the reverse rotation direction AR2 with the rotation of the rotating shaft 11, the rectifying brushes 21c and 21d and the diode D2 are used. Also in this case, when the positive electrode brush 23a is separated from the first contact portion 22d (the commutator piece 22b corresponding to the separation commutator piece 22ax), the potential changes as shown in FIG. When the brush 23b leaves, the potential changes as shown in FIG.

  According to the fourth embodiment described above, the following functions and effects can be obtained in addition to the functions and effects shown in the first and second embodiments.

  (7) The pair of brushes 23 is provided with two pairs of straightening brushes 21 (that is, straightening brushes 21a and 21b and straightening brushes 21c and 21d). The two pairs of rectifying brushes 21 are arranged such that one pair of rectifying brushes 21 (that is, the rectifying brushes 21a and 21b) are arranged on the rear side of the brush 23 with respect to the normal rotation direction AR1 of the commutator 22B, and The rectifying brush 21 (that is, the rectifying brushes 21c and 21d) is disposed on the rear side of the brush 23 with respect to the reverse rotation direction AR2 of the commutator 22B (see FIG. 10). According to this configuration, even in the rotating electrical machine 10 in which the rotating shaft 11 rotates in both directions, it is possible to prevent dielectric breakdown as compared with the conventional one while suppressing the physique to be small.

[Embodiment 5]
The fifth embodiment is a modification of the third embodiment (see FIG. 9), and will be described with reference to FIG. For simplicity of illustration and description, unless otherwise specified, the same elements as those used in Embodiments 1 to 4 are denoted by the same reference numerals and description thereof is omitted. Therefore, it demonstrates centering on the point which is different from Embodiment 1-4.

  The configuration shown in FIG. 11 is different from the configuration shown in FIG. 9 in the following points. First, rectifying brushes 21c and 21d and a diode D2 are further provided. Second, in addition to the independent commutator piece 22f provided on one side in the axial direction Ax (upper side in FIG. 11), an independent commutator piece 22h provided on the other side in the axial direction Ax (lower side in FIG. 11) is provided. Prepare. Thirdly, the shape of the plurality of commutator pieces 22g is changed as the independent commutator pieces 22h are provided.

  FIG. 11 shows a commutator 22D which is an example of the commutator 22 and is a modification of the commutator 22C. The commutator 22D includes a plurality of commutator pieces 22g, a plurality of independent commutator pieces 22f, a plurality of independent commutator pieces 22h, and the like. The number of commutator pieces 22g, the number of independent commutator pieces 22f, and the number of independent commutator pieces 22h may all be set arbitrarily. In this embodiment, the numbers of commutator pieces 22e, independent commutator pieces 22f, and independent commutator pieces 22h are the same.

  The commutator piece 22g includes a first contact part 22d, a second contact part 22c provided on both sides of the first contact part 22d in the axial direction Ax, and the like. The rectifying brushes 21a and 21b can contact the second contact portion 22c provided on one side in the axial direction Ax. The rectifying brushes 21c and 21d can contact the second contact portion 22c provided on the other side in the axial direction Ax.

  The rectifying brushes 21c and 21d are arranged not only with respect to the brush 23 (that is, the positive electrode brush 23a and the negative electrode brush 23b) but also with a position shifted in the axial direction Ax with respect to the rectifying brushes 21a and 21b. The rectifying brushes 21a and 21b are provided at positions corresponding to the independent commutator pieces 22f arranged on one side in the axial direction Ax. The rectifying brushes 21c and 21d are provided at positions corresponding to the independent commutator pieces 22h provided on the other side in the axial direction Ax.

  The independent commutator piece 22h is not connected to other elements including the winding 13a, like the independent commutator piece 22f. Therefore, the independent commutator piece 22h becomes a floating potential when it does not contact the rectifying brushes 21c and 21d.

  When the commutator 22D rotates in the forward rotation direction AR1 as the rotating shaft 11 rotates, the rectifying brushes 21a and 21b and the diode D1 are used as in the second embodiment. In this case, when the positive electrode brush 23a is separated from the first contact portion 22d (the commutator piece 22g corresponding to the separation commutator piece 22ax), the potential changes as shown in FIG. When the brush 23b leaves, the potential changes as shown in FIG.

  When the commutator 22D rotates in the reverse rotation direction AR2 with the rotation of the rotating shaft 11, the rectifying brushes 21c and 21d and the diode D2 are used. Also in this case, when the positive electrode brush 23a is separated from the first contact portion 22d (the commutator piece 22g corresponding to the separation commutator piece 22ax), the potential changes as shown in FIG. When the brush 23b leaves, the potential changes as shown in FIG.

  According to the fifth embodiment described above, the operational effects shown in the first, second, and fourth embodiments can be obtained. Further, since the diode D1 and the diode D2 are arranged with their positions shifted in the axial direction Ax, it is possible to avoid the concentration of components, wire rods, and the like in one place.

[Other Embodiments]
In the above, although the form for implementing this invention was demonstrated according to Embodiment 1-5, this invention is not limited to the said form at all. In other words, various forms can be implemented without departing from the scope of the present invention. For example, the following forms may be realized.

  In Embodiments 1 to 3 described above, a pair of rectifying brushes 21 and a pair of brushes 23 are provided (see FIGS. 2 to 4, 6, 8, and 9). Instead of this form, a configuration including two or more pairs of rectifying brushes 21 or a configuration including two or more pairs of brushes 23 may be employed. Since only the logarithm of the rectifying brush 21 and the brush 23 is different and the characteristics shown in FIG. 5 and FIG. 7 are obtained, the same effects as the first to fifth embodiments can be obtained.

  In the first to fifth embodiments described above, the diode D (D1, D2) is connected between the pair of rectifying brushes 21 (the rectifying brushes 21a and 21b and the rectifying brushes 21c and 21d) (FIGS. 1 to 5). 4, see FIGS. 6 and 8 to 11). Instead of this form, a semiconductor element (for example, a transistor or a thyristor) that performs rectification may be connected, or a resistor that generates a potential difference corresponding to the voltage across the terminals of the diode D may be connected. Even in these cases, the characteristics shown in FIG. 5 and FIG. 7 are obtained, so that the same effects as those of the first to fifth embodiments can be obtained.

  In the first to fifth embodiments described above, the stator 14 is configured by arranging a plurality of magnets in the circumferential direction (see FIG. 1). Instead of this form, it may be configured to have a stator core mainly formed of a magnetic material, a stator winding wound around the stator core, or the like. Furthermore, it is good also as a structure which embeds a magnet in a stator core. Since only the configuration of the stator 14 is different and the characteristics shown in FIGS. 5 and 7 are obtained, the same operational effects as those of the first to fifth embodiments can be obtained.

  In Embodiment 1-5 mentioned above, it was set as the structure provided with the power converter device INV separately from the rotary electric machine 10 (refer FIG. 1). Instead of this form, a configuration may be adopted in which the electric power converter INV is integrated with the rotating electrical machine 10. In other words, the power converter INV may be provided inside the rotating electrical machine 10, or the power converter INV may be fixedly provided outside the rotating electrical machine 10. Since only the form of the power conversion device INV is different and the characteristics shown in FIG. 5 and FIG. 7 are obtained, the same effects as those of the first to fifth embodiments can be obtained.

  In Embodiment 1-5 mentioned above, it was set as the structure applied to the inner rotor type rotary electric machine 10 (refer FIG. 1). Instead of this form, a configuration applied to the outer rotor type rotating electrical machine 10 may be adopted. Since only the positions of the rotor 13 and the stator 14 are different and the characteristics shown in FIGS. 5 and 7 are obtained, the same operational effects as those of the first to fifth embodiments can be obtained.

DESCRIPTION OF SYMBOLS 10 Rotating electrical machinery 11 Rotating shaft 13a Winding 20 Rectifier 21 (21a-21d) Rectifier brush 22 (22A-22D) Commutator 22a, 22b, 22e, 22g Commutator piece 23 Brush 23a Positive brush 23b Negative brush D (D1, D2) Diode

Claims (9)

A commutator (22) including a plurality of commutator pieces (22a, 22b, 22e, 22g) electrically connected to the winding (13a) and arranged in the circumferential direction (Ci) on the rotating shaft (11);
A pair of brushes (23) in contact with the commutator;
In a rectifying device (20) having a pair of rectifying brushes (21, 21a, 21b) in contact with the commutator,
The pair of brushes are electrically connected to the power source (E) directly or indirectly,
The commutation brush is disposed on the rear side of the brush with respect to the rotation direction (AR) of the commutator,
A rectifier comprising a diode (D, D1, D2) electrically connected between the pair of rectifying brushes.   The rectifying device according to claim 1, wherein the rectifying brush and the brush are arranged with their positions shifted in the axial direction (Ax).   The commutator piece is provided such that a first contact width (W1, W3) in the circumferential direction in contact with the brush is different from a second contact width (W2, W4) in the circumferential direction in contact with the commutation brush. The rectifier according to claim 1 or 2.   The rectifying device according to any one of claims 1 to 3, wherein the rectifying brush is formed in a shape that avoids simultaneous contact with the plurality of commutator pieces. The commutator has a first contact portion (22d) that contacts the brush, and a second contact portion (22c) that contacts the commutation brush,
5. The circumferential width (WR) of the rectifying brush is set to be smaller than the width (WM) of the second contact portions adjacent in the circumferential direction. The rectifier described in 1.   6. The rectifier according to claim 1, wherein the commutator includes an independent commutator piece (22 f, 22 h) that has a floating potential when not in contact with the rectifier brush. 7. Two pairs of the rectifying brushes are provided for the pair of brushes,
In the two pairs of rectifying brushes, one pair of the rectifying brushes is disposed on the rear side of the brush with respect to the positive rotation direction (AR1) of the commutator, and the other pair of rectifying brushes is the rectifying brush. The rectifier according to any one of claims 1 to 6, wherein the rectifier is disposed on a rear side of the brush with respect to a reverse rotation direction (AR2) of the child. A rectifying device (20) according to any one of claims 1 to 7;
A rotating shaft (11) provided with the commutator;
A rotor (13) fixed directly or indirectly to the rotating shaft;
A stator (14) provided via the rotor and a gap (G);
The rotary electric machine (10) characterized by having.   The rotating electrical machine according to claim 8, wherein the rotor is provided with the winding (13a).

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