JP3543889B2 - Alternator - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a generator including a rotor coil wound around a rotor core, two current collecting rings for supplying power to the rotor coil, and two fixed brushes sliding on the outer periphery of the current collecting ring. Things.
[0002]
[Prior art]
Generally, as shown in FIG. 9, the vehicle alternator 100 includes a three-phase rectifier 101, a voltage regulator 102 for regulating a generated voltage, a shaft 104 rotatably supported in a housing 103, A stator 105 fixed to the inner surface of the housing 103, a rotor 106 rotating relatively to the stator 105, a current collector 107 fixed to the outer periphery of an end of the shaft 104, and sliding on the outer periphery of the current collector 107 A brush device 108.
[0003]
Here, the three-phase rectifier 101 includes a three-phase rectifier circuit that rectifies the generated AC current with the positive-side diode 111 and the negative-side diode 112 and converts the rectified AC current into DC. The shaft 104 has a pulley 113 for a poly-V belt attached to the outer periphery of the tip. The stator 105 includes a stator core 114, a three-phase stator coil 115, and the like. The rotor 106 includes a rundle-type pole core 116, a rotor coil 117, and the like.
[0004]
The current collecting device 107 includes two slip rings 121, two connection bars 122, and the like. Note that these slip rings 121 are made of a metallic material such as a copper alloy or stainless steel in an annular shape, are molded and fixed with resin, and are press-fitted or directly molded on the outer periphery of the end of the shaft 104 of the rotor 106. It has a structure that rotates integrally with 104.
[0005]
On the other hand, the brush device 108 includes two brushes 123, a brush holder 124 that accommodates the brushes 123, and a coil spring that presses the two brushes 123 to the outer circumferences of the two slip rings 121 and electrically connects the two. 125. Note that the two brushes 123 are made of a carbonaceous member. The two brushes 123 are connected to an external connection terminal (not shown) by a pigtail 126 made of a copper wire. The brush holder 124 has a structure in which an external connection terminal is insert-molded with an electrically insulating resin material, and a slip ring cover 128 that protects the two slip rings 121 together with a rubber packing 127 is integrally formed.
[0006]
In recent years, vehicle ACs have been reduced in size and weight by restricting the mounting space for auxiliary equipment and fuel consumption due to the downsizing of the engine room of vehicles, and longer life by extending the warranty period of vehicle life. A generator is desired. As means for reducing the size and weight of the vehicle alternator, it is generally required to reduce the size of the vehicle alternator and reduce the axial size of the vehicle alternator.
[0007]
[Problems to be solved by the invention]
However, in the conventional automotive alternator 100, as shown in FIG. 9, in order to reduce the voltage drop of the excitation circuit that supplies the excitation current to the rotor coil 117 and prevent the power generation output from lowering, A brush holder 124 is installed near the voltage adjusting device 102 that controls the exciting current to the coil 117. For this reason, in order to extend the life of the two brushes 123, the radial dimension perpendicular to the axial direction of the brush holder 124 was large and could not be set long. Therefore, the axial dimensions of the brush holder 124 and the two slip rings 121 occupy a large proportion of the entire axial length of the vehicle alternator 100, and greatly hinder the miniaturization of the vehicle alternator 100. The problem has arisen.
[0008]
Further, since the brush 123 is made of a carbonaceous material, an appropriate contact area (size) of the coil spring 125 is reduced in order to reduce the electrical resistance of a contact portion of the brush 123 that contacts the outer periphery of the slip ring 121. A pressing force (spring load, contact pressure) is required, and when the contact area of the brush 123 is reduced for miniaturization, the current density increases, the temperature of the brush 123 increases, and the durability life is shortened. A problem arises.
[0009]
Further, when a carbonaceous member is used as the material of the brush 123, in order to reduce the contact electric resistance, a metal powder such as a copper powder is mixed with the carbon powder to reduce the contact electric resistance and the wear life of the brush 123. The compounding ratio was decided. By blending a metal powder such as a copper powder with the carbon powder, the weight of the brush 123 becomes heavy. Therefore, the slip ring 121 and the brush 123 take into account a problem due to vibration such as abnormal wear such as one-sided wear. I had to.
[0010]
Here, in a small DC rotating electric machine (for example, motors), there is an example in which a brush is made of a metal member (a thin metal plate or copper wire) and a rotating commutator is made of a copper alloy. Since the brush jumps due to the step of the side commutator, the contact area between the brush and the commutator is reduced and current concentration occurs at the contact portion, or the brush and the commutator are separated and an arc is generated therebetween. As a result, the commutator surface becomes rough and the brushes are partially worn, so if such problems caused by vibration do not occur, they can only be used at low voltage and constant speed rotation. The above-mentioned structure was not adopted for such a device that is used in a wide range from low-speed rotation to high-speed rotation.
[0011]
[Object of the invention]
SUMMARY OF THE INVENTION An object of the present invention is to reduce the size and weight of a brush and a brush and a collector ring by applying an appropriate contact area and contact pressure to a brush that slides on the collector ring to suppress abnormal wear caused by vibration of the brush. It is an object of the present invention to provide an AC generator capable of achieving a longer life of the sliding portion.
[0012]
[Means for Solving the Problems]
According to the first aspect of the present invention, since the brush is hardly worn by being made of metal, it is set to a size and a length in which the wear is predicted in advance like a brush made of a worn member as in the prior art. do not have to. Accordingly, the brush can be made thinner, so that the brush device can be significantly reduced in weight, and the radial size and the axial size of the brush device can be reduced. And since the axial dimension of a brush apparatus can be shortened, the axial dimension of a collector ring can be shortened. Therefore, the diameter of the AC generator in the radial direction can be reduced, and the total axial length of the AC generator can be reduced, so that the effect of reducing the weight and size of the AC generator can be obtained.
[0013]
Further, by pressing at least the tip of the brush against the outer peripheral surface of the current collecting ring by the coil spring, an appropriate contact area and contact pressure can be given to the brush sliding on the outer peripheral surface of the current collecting ring. Therefore, when the brush held by the holding member and the current collecting ring that rotates integrally with the rotor slide, abnormal wear due to the vibration of the brush can be suppressed, and the sliding between the brush and the current collecting ring can be suppressed. The life of the moving part can be prolonged. Further, since stable electric power can be supplied to the rotor coil, a stable AC output can be obtained to the stator coil with the rotation of the rotor, and the effect that the output efficiency of the stator coil can be prevented from lowering can be obtained. .
[0014]
And because the brush is made of metal, the current density changes even if the surface area of the tip of the brush is reduced in order to reduce the electrical resistance of the tip that contacts the outer peripheral surface of the current collector ring in the brush. Therefore, the effect that the temperature rise of the brush is suppressed and the durability life of the brush is extended can be obtained.
Furthermore, by using a coil spring as a pressing member that presses the brush against the outer peripheral surface of the current collecting ring, it is possible to use a compression coil spring with an optimal spring load. Therefore, an appropriate contact area and an appropriate contact pressure can be applied to the brush that slides on the outer peripheral surface of the current collecting ring, so that a stable power supply state to the rotor coil can be secured.
[0015]
AlsoBy holding the brush and the coil spring by the holding member, and electrically connecting the brush and the external connection terminal of the voltage adjustment device by using a joining means such as welding, the brush and the external connection terminal of the voltage adjustment device are connected to each other. The effect that the connection strength can be improved is obtained.
[0016]
Claim2According to the invention described in (1), by forming the tip of the brush so as to have a U-shaped cross-sectional shape, the strength of the tip of the tip member can be improved. As a result, there is obtained an effect that the durable life of the tip end portion of the brush which receives vibration from the current collecting ring can be extended.
[0017]
Claim3According to the invention described in the above,Since the brush is hardly worn by being made of metal, it is not necessary to set the size and the length of the brush in which the wear is predicted in advance unlike the brush made of the wear member as in the prior art. Accordingly, the brush can be made thinner, so that the brush device can be significantly reduced in weight, and the radial size and the axial size of the brush device can be reduced. And since the axial dimension of a brush apparatus can be shortened, the axial dimension of a collector ring can be shortened. Therefore, the diameter of the AC generator in the radial direction can be reduced, and the total axial length of the AC generator can be reduced, so that the effect of reducing the weight and size of the AC generator can be obtained.
Further, by pressing at least the tip of the brush against the outer peripheral surface of the current collecting ring by the coil spring, an appropriate contact area and contact pressure can be given to the brush sliding on the outer peripheral surface of the current collecting ring. Therefore, when the brush held by the holding member and the current collecting ring that rotates integrally with the rotor slide, abnormal wear due to the vibration of the brush can be suppressed, and the sliding between the brush and the current collecting ring can be suppressed. The life of the moving part can be prolonged. Further, since stable electric power can be supplied to the rotor coil, a stable AC output can be obtained to the stator coil with the rotation of the rotor, and the effect that the output efficiency of the stator coil can be prevented from lowering can be obtained. .
And because the brush is made of metal, the current density changes even if the surface area of the tip of the brush is reduced in order to reduce the electrical resistance of the tip that contacts the outer peripheral surface of the current collector ring in the brush. Therefore, the effect that the temperature rise of the brush is suppressed and the durability life of the brush is extended can be obtained.
Furthermore, by using a coil spring as a pressing member that presses the brush against the outer peripheral surface of the current collecting ring, it is possible to use a compression coil spring with an optimal spring load. Therefore, an appropriate contact area and an appropriate contact pressure can be applied to the brush that slides on the outer peripheral surface of the current collecting ring, so that a stable power supply state to the rotor coil can be secured.
The brush and the coil spring are held by the holding member. The brush fixing portion uses copper alloy spring steel as a material of the brush, that is, in a method using a spring characteristic which is a feature of the spring steel, and electrically and electrically connects the external connection terminal of the voltage adjusting device. Mechanically fixed. That is, the brush fixing portion has a protruding piece protruding toward the holding member in the axial direction from the substantially arc-shaped brush body of the brush, and two elastically deformable locking pieces having both sides of the protruding piece bent. ing. The brush fixing portion is configured such that the external connection terminal of the voltage adjusting device is inserted between the protruding piece and the two locking pieces, so that the elastic force between the protruding piece and the two locking pieces causes the voltage to be increased. By sandwiching the external connection terminal of the adjustment device, an effect is obtained that the connection strength between the brush fixing portion protruding from the brush main body toward the holding member and the external connection terminal of the voltage adjustment device can be improved.
[0018]
Claim4According to the invention described in the above,The number of molding dies is reduced by integrally molding the holding member for holding the brush, the casing for holding the external connection terminals of the voltage regulator, and the bearing holding portion for holding the bearing member with an electrically insulating resinous material. Therefore, the effect that the product cost of the AC generator can be reduced can be obtained.
[0019]
Further, by integrating the holding member and the bearing holding portion, it is possible to eliminate a gap between the housing and the bearing holding portion, to seal foreign matter such as water and dust entering the housing, and An advantage is obtained in that an error in assembling the shaft with respect to the shaft due to an assembly error with the bearing holding portion and an assembly error with the holding member and the bearing holding portion can be eliminated. Furthermore, since the brush device and the voltage regulator can be reduced in size, the radial size of the AC generator can be reduced, and the effect of reducing the weight and size of the AC generator can be obtained.
[0020]
Claim5According to the invention described in the above,By forming a labyrinth seal between the blower and the divided first and second holding members, it is possible to prevent foreign matter such as water and dust from entering the sliding portion between the brush and the current collecting ring. The effect that can be obtained is obtained. Further, by abolishing the rubber packing, it is possible to obtain an effect that a sealing failure can be prevented. Furthermore, since the joining surface between the first holding member and the second holding member is provided in the labyrinth seal, a new sealing member is provided to seal the joining surface between the first holding member and the second holding member. There is no necessity and the number of parts can be reduced, so that the effect of reducing the product cost of the AC generator can be obtained.
[0021]
Claim6According to the invention described in the above,By using a metal brush made of spring steel that also serves as a conventional spring, a pigtail and a graphite brush as a brush, the brush can be significantly reduced in weight, so that the spring load of the brush can be reduced. As a result, the amount of wear on the current collecting ring and the brush is significantly reduced, and abnormal wear due to the vibration of the brush is suppressed, and the life of the sliding portion between the brush and the current collecting ring can be prolonged. can get.
[0022]
According to the invention as set forth in claim 7, by using a carbonaceous current collector ring using a carbonaceous member obtained by putting carbon powder into an annular mold and sintering the current collector ring, the current collector ring itself can be used. Since the lubricating property is provided, the friction coefficient of the current collecting ring itself can be reduced. And since the current collecting ring is made of carbonaceous material, stable wear and stable power supply to the rotor coil are ensured even if the brush made of metal is slid at high speed around the current collecting ring. The effect is obtained.
[0023]
Claim8According to the invention described in the above,By providing the protruding portion having a chamfered shape at the tip of the brush, the tip of the brush can smoothly move the outer peripheral surface of the current collector ring in the axial direction of the shaft. It is possible to prevent the attachment work from being caught and to perform the disassembling work or the assembling work smoothly. Therefore, the disassembly workability and the assembling workability (productivity) can be improved, and the effect of reducing the work cost can be obtained.
[0024]
BEST MODE FOR CARRYING OUT THE INVENTION
[Configuration of First Embodiment]
FIGS. 1 to 3 show a first embodiment in which the AC generator of the present invention is applied to an AC generator for a vehicle, and FIG. 1 is a diagram showing a main structure of the AC generator for a vehicle. FIG. 2 is a view showing the overall structure of the vehicle alternator, and FIG. 3 is a view showing a state in which a three-phase rectifier, a voltage regulator, and a brush device are mounted on a rear housing.
[0025]
The AC generator 1 for a vehicle is driven by an engine via a poly-V belt (not shown), rectifies the generated AC current by a three-phase rectifier 9, converts the rectified AC current to DC, and converts the battery into a battery mounted on the vehicle. (Not shown) and an alternator for supplying necessary electric power to an electric load. The vehicle alternator 1 includes a housing 2, a stator 3, a rotor 4, a shaft 5, a current collector 6, a blower 7, a brush 8, a three-phase rectifier 9, a voltage regulator 10, and the like. .
[0026]
[Description of housing]
Next, the housing 2 will be described with reference to FIGS. The housing 2 includes a front housing (drive frame) 11 and a rear housing (rear frame) 12 made of two aluminum die-casts, and is fastened by a plurality of stud bolts 13 and nuts 14.
[0027]
A front bearing (front bearing member) 15 that rotatably supports the front side (tip side) of the shaft 5 is fixed to the front housing 11 by press-fitting and caulking into a cylindrical bearing holding portion 16. A rear bearing (rear bearing member) 17 as a bearing member for rotatably supporting the rear side (rear end side) of the shaft 5 is fixed to the rear housing 12 by press-fitting into a cylindrical bearing holding portion 18. I have.
[0028]
In order to suck cooling air into the housing 2, a large number of ventilation ports 19 are provided in the front housing 11, and a large number of ventilation ports 20 and a large number of exhaust ports 21 are provided in the rear housing 12 in a substantially annular shape. I have. Further, a stay portion 22 fastened and fixed to an upper bracket (not shown) of the engine is provided at an upper portion of the front housing 11, and a stay portion 23 fastened and fixed to a lower bracket (not shown) of the engine is provided at a lower portion. It is integrally molded. The rear housing 12 is integrally formed with a stay 24 which is fastened and fixed to a lower bracket of the engine. Bolt holes 25 to 27 through which bolts are inserted pass through these stay portions 22 to 24.
[0029]
[Description of stator]
Next, the stator 3 will be described with reference to FIG. The stator 3 is a stator including a stator core 31 fixed to the inner surface of the housing 2 and a three-phase stator coil 32 wound around the stator core 31.
[0030]
The stator core 31 constitutes an armature core, is formed of a laminated core formed by laminating a plurality of thin steel sheets made of a magnetic material, and is press-fitted and fixed to the inner peripheral surface of the front housing 11 to be integrated. A number of slots (not shown) are formed at equal intervals on the inner peripheral side of the stator core 31.
[0031]
The three-phase stator coil 32 is a three-phase armature winding that is connected by a Y-connection or a Δ-connection and induces a three-phase AC output as the rotor 4 rotates. The winding ends of these stator coils 32 are electrically connected to the three-phase rectifier circuit of the three-phase rectifier 9 by soldering or the like.
[0032]
[Description of rotor]
Next, the rotor 4 will be described with reference to FIGS. The rotor 4 is a rotor that rotates integrally with the shaft 5 at a portion that functions as a magnetic field. The rotor 4 includes a shaft 5, a Landel-type pole core 33 fixed to the shaft 5, a field coil 34 wound around the pole core 33, and a current collector 6 for supplying an exciting current to the field coil 34. , And a blower 7 for generating cooling air.
[0033]
The pole core 33 is a rotor core (field pole, field iron core, or rotor iron core) of the present invention, and has a field coil 34 wound at the center and is made of a ferromagnetic material. In the pole core 33, when an exciting current flows through the field coil 34, all of the claw-shaped magnetic pole portions become N poles, and all of the other claw-shaped magnetic pole portions become S poles. A blower 7 for sucking cooling air into the housing 2 is attached to the rear side wall surface of the other claw-shaped magnetic pole portion by means such as welding.
[0034]
The field coil 34 is a rotor coil of the present invention, and is wound around a center portion of the pole core 33 via a coil bobbin 35, and is an excitation winding (rotor winding) that magnetizes the pole core 33 when an excitation current flows. is there. The field coil 34 has terminal wires at both ends electrically connected to connection bars (not shown) by using soldering or the like. The coil bobbin 35 is made of an electrically insulating resin material that electrically insulates the field coil 34 and the pole core 33.
[0035]
[Description of shaft]
Next, the shaft 5 will be described with reference to FIGS. The shaft 5 is rotatably supported by bearing holding portions 16 and 18 of the housing 2 via front and rear bearings 15 and 17. A V-ribbed pulley (a pulley for poly V-belt) 36 for transmitting the rotational power of the engine to the shaft 5 is provided at one end (a front end, a front end) of the shaft 5 with a nut 37 having a seat and the front bearing 15. It is fastened and fixed between.
[0036]
The V-ribbed pulley 36 is drivingly connected to a poly-V belt pulley (not shown) mounted on an output shaft (crankshaft) of the engine via a transmission means (not shown) such as a poly-V belt. Note that a clutch means such as an electromagnetic clutch may be provided between the shaft 5 and the V-ribbed pulley 36.
[0037]
[Description of current collector]
Next, the current collector 6 will be described with reference to FIGS. 1, 2, and 4. FIG. The current collector 6 includes two carbonaceous current collector rings (hereinafter, referred to as slip rings) 41 and 42 used to connect the battery and voltage regulator 10 to the field coil 34 through the brush device 8. It is composed of two connection bars (slip ring terminals) 43 and 44 connected to each of these slip rings 41 and 42.
[0038]
The two slip rings 41 and 42 are provided on the outer periphery of the other end (rear end, rear end) of the shaft 5. As a material of these slip rings 41 and 42, a carbon (carbon) material obtained by putting carbon powder in which copper and carbon are mixed into an annular mold and firing it is used.
[0039]
Note that the slip ring 41 is a positive electrode side carbonaceous current collecting ring, and the slip ring 42 is a negative electrode side carbonaceous current collecting ring. As shown in FIG. 2, terminal wires 38 and 39 of the field coil 34 are electrically connected to the other ends of the two connection bars 43 and 44 by means such as soldering. As the material of the two slip rings 41 and 42, for example, carbon powder, natural graphite, electric graphite, metal graphite, or the like using a foam skeleton metal of a copper alloy as a metal base may be used.
[0040]
[Explanation of blower]
Next, the blower 7 will be described with reference to FIGS. The blower 7 is integrally formed of an electrically insulating resin material, and two slip rings 41 and 42 and two connection bars 43 and 44 are insert-molded with the resin material. The blower 7 is also a terminal protection member that protects the connection between the wiring portions of the two slip rings 41 and 42 and the two connection bars 43 and 44.
[0041]
The blower 7 has a plurality of wings (blades) 45 that constitute a centrifugal fan, an annular plate-shaped wing fixing portion 46 that supports these wings 45, and a cylindrical shape obtained by insert-molding the slip rings 41 and 42. And the like. The wing fixing portion 46 is fixed to the side surface on the rear end side of the pole core 33, and has a concave portion 48 as a fitting portion on an opposing surface (rear end surface) facing the brush device 8.
[0042]
The collector ring fixing portion 47 is integrated with the two slip rings 41 and 42 and the two connection bars 43 and 44 and is press-fitted and fixed to the outer periphery of the other end of the shaft 5. As the resinous member, for example, it is desirable to use, for example, polyphenylene sulfide resin (PPS resin) which is excellent in electric insulation and heat resistance, high in strength and excellent in dimensional stability.
[0043]
[Description of brush device]
Next, the brush device 8 will be described with reference to FIGS. The brush device 8 includes two metallic brushes (hereinafter, referred to as brushes) 51 and 52 that slide on the outer circumference of each of the two slip rings 41 and 42 and are electrically connected to each other. , 52 for supporting and fixing the brushes, coil springs 54, 55 for applying a predetermined contact pressure to the two brushes 51, 52, and two connection terminals 56, 57 insert-molded on the brush holder 53, etc. It is composed of
[0044]
The two brushes 51 and 52 are integrally formed by bending a metal plate having a plate thickness of, for example, 0.5 to 2.0 mm only by pressing, and the field coil 34 is provided via two slip rings 41 and 42. Is a fixed-side brush for supplying an exciting current to the brush. As a material of the brushes 51 and 52, a metal member (for example, a thin conductive material such as a copper alloy or a conductive thin elastic material such as a copper alloy) is used. The brush 51 is a positive fixed brush, and the brush 52 is a negative fixed brush.
[0045]
The tips of the two brushes 51, 52 are contact portions (brush body) that contact the outer peripheral surfaces of the two slip rings 41, 42, and are press-formed so as to have a U-shaped cross section. I have. The rear ends of the two brushes 51 and 52 are connected to the connection terminals 56 and 57 via two pigtails (a positive-side pigtail is not shown) 58. And is press-formed so as to have a one-character cross section.
[0046]
The two pigtails 58 are braided wires of a conductive metal wire such as a copper wire, and the outside is covered with an electrically insulating member. These pigtails 58 are joined at one end to the rear ends of the two brushes 51, 52 using joining means such as brazing, and the other end is attached to the tip of the two connection terminals 56, 57. It is joined using joining means such as attaching.
[0047]
The brush holder 53 is a holding member of the present invention, and is a brush (brush) holder for holding and fixing the two brushes 51 and 52, and is made of an electrically insulating resin material (for example, PPS resin or the like). . The brush holder 53 is divided into a first brush holding member 61 and a second brush holding member 62. The first brush holding member 61 is a first holding member of the present invention, and is a cylindrical holding member (brush holder, brush holder body) 63, a cylindrical member extending in the axial direction from the front end side of the brush holding member 63. A current collecting ring covering portion (slip ring cover portion) 65 and a casing 66 of the voltage regulator 10 described later are integrally formed.
[0048]
The brush holding portion 63 insert-molds the connection terminals 56 and 57, and holds the connection terminals 56 and 57 in a state where the respective tips of the connection terminals 56 and 57 project. Square cylindrical boxes (brush storage portions) 67a and 67b for storing the brushes 51 and 52, the coil springs 54 and 55, and the pigtail 58 are integrally formed on a part of the inner peripheral surface of the brush holding portion 63. I have. The current collecting ring covering section 65, together with the blower 7, covers the periphery of the sliding portion between the two slip rings 41, 42 and the two brushes 51, 52 in a substantially L-shape.
[0049]
The second brush holding member 62 is a second holding member of the present invention, and is integrally formed into a substantially cylindrical shape by the same resin material as the first brush holding member 61, and is formed on the outer peripheral surface of the first brush holding member 61. It is joined using joining means such as welding. The second brush holding member 62 has a convex portion 68 as a fitted portion fitted to the concave portion 48 of the wing fixing portion 46 at a tip portion (front end portion) of the blowing device 7 facing the wing fixing portion 46. Have. The convex portion 68 is a portion protruding forward from the front end of the current collecting ring covering portion 65 of the first brush holding member 61.
[0050]
For this reason, the current collecting ring covering portion 65 of the first brush holding member 61 and the convex portion 68 of the second brush holding member 62 have a substantially U-shaped cross section between the concave portion 48 of the wing fixing portion 46. A labyrinth seal 60 is formed. The labyrinth seal 60 is formed in an annular shape without a break all around. In the second brush holding member 62, a joint between the first brush holding member 61 and the current collecting ring covering portion 65 is provided in the labyrinth seal 60.
[0051]
The rear end of the brush holding portion 63 of the first brush holding member 61 and the rear end of the second brush holding member 62 are press-fitted and fixed to the front end of the bearing holding portion 18 for holding the rear bearing 17. A gap formed between the retainer 53 and the bearing holding portion 18 of the rear housing 12 is sealed. Therefore, the cylindrical gap S in which the sliding portion between the two slip rings 41 and 42 and the two brushes 51 and 52 exists is hermetically sealed by the blower 7 and the brush holder 53.
[0052]
The two coil springs 54 and 55 are compression coil springs that press the two brushes 51 and 52 against the outer peripheral surfaces of the two slip rings 41 and 42, respectively. The two coil springs 54 and 55 have their tips held on the back surfaces of the tips of the two brushes 51 and 52, and the other ends held on the bottom surfaces of the boxes 67 a and 67 b of the first brush holding member 61. I have.
[0053]
The connection terminals 56 and 57 are made of a metallic member such as an aluminum alloy or a copper alloy. The connection terminal 56 is a positive-side power supply terminal that has a substantially inverted L-shaped cross section, is fixedly fixed to a DC output terminal 71 of the three-phase rectifier 9 by a fixing screw 72, and is electrically connected. The connection terminal 57 is an external connection terminal of the brush device 8 and an external connection terminal of the voltage regulator of the present invention, and has a substantially L-shaped cross-section so as to extend on the opposite side to the connection terminal 56. It is a negative-side power supply terminal that is formed and provided integrally with an exciting current output terminal (not shown) of the voltage regulator 10.
[0054]
[Description of three-phase rectifier]
Next, the three-phase rectifier 9 will be described with reference to FIGS. The three-phase rectifier 9 is a so-called rectifier, and includes a DC output terminal 71, a positive cooling fin 73, a negative cooling fin 74, three positive diodes 75, three negative diodes 76, and a terminal block. 77 and the like.
[0055]
The DC output terminal 71 is an external connection terminal of the three-phase rectifier 9. One end of the DC output terminal 71 is electrically connected to a positive electrode of the battery via a conductive wire (not shown), and the other end is a connection terminal 56 of the brush device 8. And it is electrically connected to the positive electrode side cooling fin 73 by tightening the fixing screw 72. The DC output terminal 71 is a terminal that supplies a charging current to the battery (DC output positive terminal), and constitutes a terminal B of the vehicle AC generator 1.
[0056]
The positive-electrode-side cooling fins 73 are integrally formed with the negative-electrode-side cooling fins 74 in a predetermined shape so as to surround the brush holder 53, and are arranged along the side surface of the rear housing 12. The positive cooling fin 73 is fixed to the inner surface of the rear housing 12 via an insulating member (not shown). The negative cooling fin 74 is grounded to the body via the rear housing 12. That is, the positive cooling fin 73 is electrically connected to the positive (+) side of the battery, and the negative cooling fin 74 is electrically connected to the negative (−) side of the battery. The positive and negative cooling fins 73 and 74 are made of a conductive metal plate (eg, an aluminum plate) having excellent thermal conductivity, and generate heat from the three positive and negative diodes 75 and 76. In addition to the heat dissipating fins that dissipate heat, they also serve as rectifying element holding means for holding and fixing three positive and negative diodes 75 and 76.
[0057]
The three positive-side and negative-side diodes 75 and 76 are positive-side and negative-side rectifying elements that rectify the AC output of the three-phase stator coil 32 and convert (rectify) the DC output into a DC output. One end (lead wire) of each of the three positive-side and negative-side diodes 75 and 76 is electrically connected to three AC input terminals 78 by soldering, and the other end is connected to the positive-side and negative-side cooling fins, respectively. 73 and 74 are electrically connected by soldering. A three-phase rectifier circuit is composed of the DC output terminal 71, the positive and negative cooling fins 73 and 74, the three positive electrodes, the three negative diodes 75 and 76, and the three AC input terminals 78. You.
[0058]
The terminal block 77 is made of an electrically insulating resinous material (for example, PPS resin or the like) into a predetermined shape, insert-molds and holds three AC input terminals 78, and cools the positive electrode side cooling fins 73 and the negative electrode side. The cooling fins 74 are electrically insulated. The terminal block 77 fixes the positive and negative cooling fins 73 and 74 with fixing screws 79.
[0059]
[Description of voltage regulator]
Next, the voltage regulator 10 will be described with reference to FIGS. The voltage regulator 10 is an energization control circuit of the present invention, and is an IC regulator including various external connection terminals (not shown) such as an excitation current output terminal, an integrated circuit (not shown), a casing 66, and the like. It is. The excitation current output terminal is an external connection terminal of the voltage regulator 10 and is integrally formed with the connection terminal 57 by a metal member such as a copper alloy as described above, and is held by the casing 66 fixed to the rear housing 12. And are mechanically connected to two brushes 51 and 52.
[0060]
The integrated circuit is a voltage adjusting unit that controls the exciting current supplied to the field coil 34 to adjust the generated voltage of the three-phase stator coil 32. This integrated circuit incorporates a power transistor as a switching element for controlling energization and de-energization of the field coil 34, a back electromotive force absorbing diode for attenuating an exciting current flowing through the field coil 34, and the like.
[0061]
The casing 66 is integrally formed with the brush holder 53 by an electrically insulating resin material (for example, PPS resin) and has a plurality of brackets 81 which are fastened and fixed to the rear housing 12 by fixing screws 80. Thus, the casing 66 functions as a brush fixing means for fixing the brush holder 53 and the two brushes 51 and 52 to the rear housing 12. Further, inside the casing 66, electronic components such as integrated circuits are molded with an epoxy resin-based resinous material.
[0062]
[Operation of the first embodiment]
Next, the operation of the automotive alternator 1 of this embodiment will be briefly described with reference to FIGS.
[0063]
When the engine mounted on the vehicle starts, the rotational power of the engine is transmitted to the V-ribbed pulley 36 via a transmission means such as a poly V belt, and is rotatably supported by the housing 2 via the front and rear bearings 15 and 17. The rotation of the shaft 5 rotates the rotor 4. At this time, the pole core 33, the field coil 34, and the two slip rings 41 and 42 rotate integrally with the shaft 5.
[0064]
When the voltage regulator 10 starts supplying power to the field coil 34, the battery → DC output terminal 71 → connection terminal 56 → pigtail (not shown) → slip ring 41 → connection bar 43 → field coil 34 → connection bar 44 → slip ring 42 → brush 52 → pigtail 58 → connection terminal 57 (excitation current output terminal) → voltage adjusting device 10 → rear housing 12 → excitation current flows as in the body.
[0065]
Therefore, when a voltage is applied from the battery to the field coil 34 and an exciting current flows through the field coil 34, the two claw-shaped magnetic pole portions of the pole core 33 are magnetized. As a result, one of the claw-shaped magnetic pole portions becomes an N pole, and the other claw-shaped magnetic pole portion becomes an S pole.
[0066]
Then, alternating current is sequentially induced in the three-phase stator coil 32 wound around the stator core 31 of the stator 3 that rotates relative to the rotor 4, and the generated voltage rises rapidly. This three-phase AC current is input to the three-phase rectifier circuit via three AC input terminals 78. That is, the three-phase alternating current is rectified and converted into a direct current by being input to the three positive diodes 75 and the three negative diodes 76.
[0067]
When the generated voltage of the three-phase stator coil 32 (the voltage of the DC output terminal 71, the terminal B voltage) exceeds the battery voltage, the rectified DC current, that is, the charging current, becomes three positive-side diodes 75 → The cooling fin 73 is supplied to the battery via the DC output terminal 71 and the conductive wire. As a result, the charging current flows through the battery, thereby charging the battery and supplying power to the electric load mounted on the vehicle.
[0068]
Here, heat is generated when the electric components of the three-phase stator coil 32, the field coil 34, the three-phase rectifier 9 and the voltage regulator 10 of the vehicle alternator 1 are energized. This heat is cooled by the cooling air being sucked into the housing 2 by the rotation of the rotor 4 and the rotation of the plurality of wings 45 fixed to the pole core 33.
[0069]
Specifically, as shown in FIG. 2, the three-phase stator coil 32 of the stator 3 and the field coil 34 of the rotor 4 have a large number of ventilation holes 19 and a large number of holes formed in the front housing 11 and the rear housing 12. Is cooled directly by the cooling air of the plurality of wings 45 sent through the ventilation holes 20.
[0070]
The heat generated by the three positive-side and negative-side diodes 75 and 76 is generated by the cooling air sent through the ventilation holes 20 of the rear housing 12 to the positive and negative-side cooling fins 73 and 74. When the positive and negative cooling fins 73 and 74 are cooled, heat is radiated through the positive and negative cooling fins 73 and 74.
[0071]
When the cooling air is sucked into the housing 2, foreign substances such as water and dust also enter the housing 2. In particular, when foreign matter enters through the ventilation hole 20 of the rear housing 12, there is a possibility that the foreign matter enters a sliding portion between the slip rings 41 and 42 and the brushes 51 and 52. However, in this embodiment, the bearing holding portion 64 of the brush holder 53 seals the rear housing 12 side of the cylindrical gap S where the sliding portions between the slip rings 41 and 42 and the brushes 51 and 52 exist.
[0072]
Further, the outer peripheral side of the cylindrical gap S is sealed by the brush holding portion 63 and the current collecting ring covering portion 65, and the labyrinth seal 60 between the concave portion 48 of the blade fixing portion 46 and the convex portion 68 of the brush holder 53. The pole core 33 side of the cylindrical gap S is sealed. Thereby, it is possible to prevent the abrasion powder generated in the sliding portion between the slip rings 41 and 42 and the brushes 51 and 52 from scattering into the housing 2.
[0073]
Even if foreign matter such as water or dust enters the housing 2, the sliding between the slip rings 41, 42 and the brushes 51, 52 in the space surrounded by the blower 7 and the brush holder 53. It is also possible to prevent foreign matter such as water and dust from entering the cylindrical space S where the portion exists.
[0074]
By operating the vehicle alternator 1 for a long period of time, the two slip rings 41 and 42 provided integrally on the outer periphery of the shaft 5 and the connection terminals 56 and 57 held by the brush holder 53 are connected. The two mechanically fixed brushes 51 and 52 slide and wear due to high-speed rotation.
[0075]
However, since the two slip rings 41 and 42 are made of a carbonaceous material, they have self-lubricating properties. That is, by reducing the friction coefficient of the slip rings 41 and 42 themselves, the wear amount of the slip rings 41 and 42 is significantly reduced as compared with the conventional copper alloy slip ring 121.
[0076]
In addition, since the two brushes 51 and 52 are made of a metal member, the weight is reduced and the spring load is reduced, so that the wear amount of the two brushes 51 and 52 is greatly reduced. Therefore, the durable life of the two slip rings 41 and 42 and the two brushes 51 and 52 can be extended.
[0077]
[Effect of the first embodiment]
As described above, in the vehicle alternator 1 of this embodiment, the outer ends of the slip rings 41 and 42 are pressed by pressing the tips of the brushes 51 and 52 against the outer peripheral surfaces of the slip rings 41 and 42 by the coil springs 54 and 55. Appropriate contact area and contact pressure can be given to the brushes 51 and 52 sliding on the surfaces. For this reason, when the brushes 51 and 52 held by the holding member and the slip rings 41 and 42 rotating integrally with the shaft 5 slide, abnormal wear due to vibration of the brushes 51 and 52 can be suppressed. The life of the sliding portions between the brushes 51 and 52 and the slip rings 41 and 42 can be extended.
[0078]
In addition, since stable electric power can be supplied to the field coil 34, a stable AC output can be generated in the three-phase stator coil 32 with the rotation of the pole core 33 of the rotor 4. Can be prevented from lowering in output efficiency. In this embodiment, the metal brushes 51 and 52 are pressed against the slip rings 41 and 42 by using the urging forces of the coil springs 54 and 55. The reason for using the coil springs 54 and 55 is that the amount of spring deformation with respect to the spring load can be increased as compared with the leaf spring alone, and that the contact pressure can be easily changed by changing to a coil spring having a different spring constant. Is mentioned.
[0079]
Next, the effect when the slip rings 41 and 42 are manufactured from a carbonaceous material and the brushes 51 and 52 are manufactured from a metal material will be described.
In the case of the conventional structure, since the material of the brush is a wear member (carbonaceous member), it is necessary to set the size and length of which the wear is predicted in advance, and further, the drop voltage of the excitation circuit of the voltage regulator is reduced. For this purpose, a voltage adjusting device is arranged near the brush device. Therefore, as shown in FIG. 9, the physique of the vehicle alternator 100 cannot be reduced, which hinders downsizing of the vehicle alternator 100.
[0080]
However, when the brushes 51 and 52 are made of a metallic material as in this embodiment, the brushes 51 and 52 are hardly worn out. There is no need to set it to length. Thereby, the brushes 51 and 52 can be made extremely thin. That is, since the brushes 51 and 52 can be made of a thin plate conductive material or a thin plate elastic material, the brush device 8 including the brushes 51 and 52 and the brush holder 53 can be significantly reduced in weight and size. Therefore, even when the voltage regulator 10 is installed in the vicinity of the brushes 51 and 52, the physical size of the vehicle alternator 1 can be reduced, and the axial dimension can be reduced. , And can be downsized.
[0081]
Further, as in the present invention, the slip rings 41 and 42 are made of a carbonaceous material, and the self-lubricating properties (reduction of friction coefficient) of the slip rings 41 and 42 and the contact probability with the brushes 51 and 52 are greatly increased. Therefore, the amount of wear can be significantly reduced as compared with the conventional metallic current collector ring (slip ring 121 in FIG. 9). Further, since the spring loads of the brushes 51 and 52 are reduced to reduce the weight of the brushes 51 and 52, the wear amount of the slip rings 41 and 42 can be further reduced. Can be achieved. Therefore, a longer life of the vehicle alternator 1 can be achieved.
[0082]
Since the brushes 51 and 52 are made of a metallic material, the brushes 51 and 52 have a small contact resistance with the outer circumference of the slip rings 41 and 42 in order to reduce the electrical resistance. Since the current density does not change even if the surface area of the portion is reduced, the temperature rise of the brushes 51 and 52 is suppressed, and the durability life of the brushes 51 and 52 is extended. On the other hand, although the slip rings 41 and 42 are made of carbonaceous material, the portions of the annular slip rings 41 and 42 that come into contact with the brushes 51 and 52 are a part of the circumferential dimension, so The temperature rise of the slip rings 41 and 42 is also suppressed, and the durable life of the slip rings 41 and 42 is extended. Therefore, a longer life of the vehicle alternator 1 can be achieved.
[0083]
Since the slip rings 41 and 42 are made of a carbonaceous material, the brushes 51 and 52 are made of a metal material, and the brushes 51 and 52 are driven at high speed around the outer circumference of the slip rings 41 and 42 (for example, (10000 rpm or more), it is possible to secure stable wear and energization to the field coil 34, so that a stable AC output is supplied to the three-phase stator coil 32 with the rotation of the pole core 33 of the rotor 4. By being able to generate | occur | produce, the fall of the output efficiency of the alternator 1 for vehicles can be prevented.
[0084]
Next, the sealing performance of the blower 7 and the brush holder 53 will be described. As described above, when the rotor 4 rotates within the stator 3, the two slip rings 41, 42 and the two brushes 51, 52 generate wear powder due to sliding between them, and the inside of the housing 2 Adhesion to electrical components (for example, electrical components of the three-phase rectifier 9, electronic components of the voltage regulator 10, three-phase stator coils 32 and field coils 34, etc.) can cause problems such as insulation deterioration and poor grounding. There is. On the other hand, when the vehicle alternator 1 is flooded during running of the vehicle, the water that has entered the housing 2 touches the two slip rings 41 and 42 and the two brushes 51 and 52, causing these slips. The rings 41 and 42 and the brushes 51 and 52 may be abnormally worn to shorten the life of the vehicle alternator 1.
[0085]
However, in the automotive alternator 1 of this embodiment, the slip rings 41 and 42 of the rotor 4 are insert-molded into the blower 7 using a resinous material, and the wing fixing portion 46 of the blower 7 and the brush holder 53 are collected. An annular labyrinth seal 60 is provided between the concave portion 48 and the convex portion 68 formed on the surfaces facing each other with the electric ring covering portion 65.
[0086]
Therefore, the cylindrical gap S in which the sliding portions of the two slip rings 41 and 42 and the two brushes 51 and 52 are present is hermetically sealed by the labyrinth seal 60 on the front end side (the rear end wall side of the pole core 33) ( The outer peripheral side is hermetically sealed (sealed) by a current collecting ring covering portion 65 of the brush holder 53, and the rear end side (the side wall side of the rear housing 12) is the brush holding portion 63 and the bearing holding portion of the brush holder 53. The seal 18 is hermetically sealed. As a result, abrasion powder generated by sliding between the two slip rings 41 and 42 and the two brushes 51 and 52 is not scattered outside through the cylindrical gap S, so that electric components (for example, three-phase Adhesion to the electric components of the rectifier 9, the electronic components of the voltage regulator 10, the three-phase stator coil 32 and the field coil 34) can avoid problems such as insulation deterioration and poor grounding.
[0087]
In addition, foreign matters such as water and dust that have entered the housing 2 are prevented from entering the cylindrical gap S where the sliding portion between the two slip rings 41 and 42 and the two brushes 51 and 52 exists. Therefore, abnormal wear of the two slip rings 41 and 42 and the two brushes 51 and 52 can be suppressed. That is, the two slip rings 41 and 42 and the two brushes 51 and 52 can be protected from foreign substances such as water and dust entering from the outside. 51, 52 can be extended. Thereby, the life of the vehicle alternator 1 can be extended.
[0088]
Next, the effect when the brush holding part 63 of the brush holder 53 and the casing 66 of the voltage regulator 10 are integrated will be described.
The brush holding portion 63 and the casing 66 are resin molded products made of a resinous material conventionally, and the number of molds can be reduced by integrally molding both.
[0089]
When the brush holding portion 63 and the casing 66 are manufactured separately, the connection terminal 56 of the brush device 8 and the exciting current output terminal of the voltage regulator 10 are electrically connected to each other to secure a space such as screwing or welding. Is required, and the brush device 8 and the voltage adjusting device 10 are increased in size. However, the vehicle alternator 1 of this embodiment does not require a space such as screw fastening or welding, so that the brush device 8 and the voltage regulator 10 can be reduced in size. Therefore, downsizing of the vehicle alternator 1 can be achieved.
[0090]
Next, an effect when the plurality of wing portions 45 and the wing fixing portion 46 of the blower 7 are integrated with the collecting ring fixing portion 47 will be described.
The plurality of wing portions 45 and the wing fixing portions 46 of the blower device 7 and the current collecting ring fixing portion 47 are integrally formed of an electrically insulating resinous material, so that the blower device 7 and the current collecting ring can be formed in one molding die. Since the fixing portion 47 can be formed, the number of molds can be reduced. When the blower 7 and the collector ring fixing portion 47 are press-fitted and fixed to the rear end face of the pole core 33 and the outer periphery of the rear end of the shaft 5, the slip rings 41 and 42 and the connection bars 43 and 44 are simultaneously attached to the shaft 5. Assembly work can also be performed. Therefore, the number of man-hours for assembling these to the rotor 4 and the shaft 5 can be reduced, and the working time is shortened. As a result, the productivity of the vehicle alternator 1 can be improved, so that the product cost of the vehicle alternator 1 can be reduced.
[0091]
[Configuration of Second Embodiment]
4 to 8 show a second embodiment in which the AC generator of the present invention is applied to a vehicle AC generator. FIG. 4 is a diagram showing the entire structure of the vehicle AC generator. 5 is a diagram showing a brush device, a three-phase rectifier, and a voltage regulator.
[0092]
The brush device 8 of this embodiment includes two brushes 51 and 52 which slide on the outer circumference of each of the two slip rings 41 and 42 and are electrically connected to each other, and support and fix these brushes 51 and 52. The brush holder 53 includes coil springs 54 and 55 for applying a predetermined contact pressure to the two brushes 51 and 52, and two connection terminals 56 and 57 insert-molded into the brush holder 53. .
[0093]
The two brushes 51 and 52 are made of a metal material (for example, a conductive thin plate elastic material such as phosphor bronze or beryllium copper, which is a spring steel of a copper alloy), and have a plate thickness of, for example, 0.5. It is integrally formed by bending a metal plate of ~ 2.0 mm only by pressing. As shown in FIGS. 6 and 7, these brushes 51 and 52 are provided with a substantially arc-shaped brush body (arm) provided so as to surround each of the two slip rings 41 and 42 in a 円 arc shape. , Arm-shaped portion) 90 and a brush fixing portion 91 protruding from the brush main body 90 toward the brush holder 53. At the tip of the brush main body 90, contact portions 92 that are respectively in contact with the outer peripheral surfaces of the slip rings 41 and 42 are integrally formed.
[0094]
The contact portion 92 is a sliding portion that slides on the outer peripheral surface of each of the slip rings 41 and 42, and secures a contact pressure with each of the slip rings 41 and 42 by the spring characteristics of the brush main body 90 itself. Three extended pieces (projecting portions) 93 protrude from three sides of these contact portions 92. The three extension pieces 93 extend toward both sides in the axial direction from both ends in the axial direction of each of the slip rings 41 and 42, or extend outward from the distal ends of the respective slip rings 41 and 42 in the circumferential direction. Each of the contact portions 92 is formed in a shape (chamfered shape) that is extended and warped outward with respect to the axial direction or the circumferential direction.
[0095]
Since the brush fixing portion 91 uses copper alloy spring steel as a material of the brushes 51 and 52, the brush fixing portions 91 are electrically and mechanically connected to the connection terminals 56 and 57 by a method using a spring characteristic which is a characteristic of the spring steel. Is fixed. For this reason, the brush fixing portion 91 of this embodiment is formed in a faston shape which is a minimum space for performance and manufacturing. That is, as shown in FIG. 6, the brush fixing portion 91 has a protruding piece 94 that protrudes in the axial direction from the rear end (top end) of the brush main body 90, and both sides of the protruding piece 94 have a substantially long cross-sectional shape. It has two elastically deformable locking pieces 95 bent so as to draw a circular circumference. The brush fixing portion 91 is configured such that the distal ends of the connection terminals 56 and 57 are inserted between the protruding piece 94 and the two locking pieces 95, so that the elastic force between the protruding piece 94 and the locking piece 95 is formed. Hold the distal ends of the connection terminals 56 and 57.
[0096]
The brush holder 53 is a holding member of the present invention, and is divided into a first brush holding member 61 and a second brush holding member 62 as shown in FIGS. The first brush holding member 61 includes a brush holding portion 63, a cylindrical bearing holding portion (bearing holder portion) 64 provided on the inner peripheral side of the brush holding portion 63, and an axial direction from the front end side of the brush holding portion 63. The extended cylindrical collector ring cover 65 and the casing 66 of the voltage regulator 10 are integrally formed. The bearing holding portion 64 is press-fitted into the bearing holding portion 18 of the rear housing 12, and the rear bearing 17 is fixed to the inner peripheral side by press-fitting.
[0097]
The second brush holding member 62 has a rectangular cylindrical shape for storing the brushes 51, 52 and the coil springs 54, 55 together with the joint portions of the first brush holding member 61 with the brush holding portion 63 and the current collecting ring covering portion 65. (Brush storage portions) 67a and 67b are formed. Further, a through-hole 62b through which the connection terminals 56 and 57 penetrate is formed in the annular portion on the rear end side of the second brush holding member 62. The first and second brush holding members 61 and 62 are fitted portions that are fitted to the protruding portions 49 of the wing fixing portion 46 at front ends (front ends) of the blowing device 7 facing the wing fixing portion 46. Has a concave portion 69.
[0098]
Therefore, a labyrinth seal 60 having a substantially U-shaped cross section is formed between the concave portion 69 of the first and second brush holding members 61 and 62 and the convex portion 49 of the wing fixing portion 46. The labyrinth seal 60 is formed in an annular shape without a break all around. In the second brush holding member 62, a joint between the brush holding portion 63 of the first brush holding member 61 and the current collecting ring covering portion 65 is provided in the labyrinth seal 60.
[0099]
Further, the bearing holding portion 64 of the first brush holding member 61 is press-fitted and fixed to the inner periphery of the front end of the bearing holding portion 18 for holding the rear bearing 17, and the brush holding device 53 and the bearing holding portion 18 of the rear housing 12 are fixed. The gap formed between them is sealed. Therefore, the cylindrical gap S in which the sliding portion between the two slip rings 41 and 42 and the two brushes 51 and 52 exists is hermetically sealed by the blower 7 and the brush holder 53.
[0100]
The two coil springs 54 and 55 are the coil springs of the present invention, and are compression coil springs that press the contact portions 92 of the two brushes 51 and 52 against the outer peripheral surfaces of the two slip rings 41 and 42, respectively. is there. The two coil springs 54, 55 have their tips held on the back surface of the contact portion 92 of the two brushes 51, 52, and the other ends have the boxes 67 a, 67 b of the first and second brush holding members 61, 62. It is held on the bottom surface.
The distal ends of the connection terminals 56 and 57 are formed in a tapered shape so as to be easily inserted between the protruding piece 94 and the locking piece 95 of the brush fixing portion 91 of each of the brushes 51 and 52.
[0101]
[Effect of Second Embodiment]
The vehicle alternator 1 of this embodiment has the same effects as the first embodiment, and further has the following effects.
First, the effect when the copper alloy spring steel is used as the material of the brushes 51 and 52 of the automotive alternator 1 will be described.
When a carbonaceous brush is used as a brush as in the past, metal powder such as copper powder is mixed with carbon powder in order to reduce the contact electric resistance, and it is blended according to the contact electric resistance and the wear life of the brush. Had decided the ratio. By blending metal powder such as copper powder with carbon powder, the weight of the brush becomes heavy, so that problems due to vibration (for example, excessive wear between the brush and the slip ring) must be considered. In addition, the vibration resistance of the brush is generally represented by the following equation (1) according to the literature of the mechanical design document.
[0102]
(Equation 1)
Vibration resistance∝ ｛(k × spring load) / (brush weight)｝ + ｛spring weight｝
From the above equation (1), it is understood that when the weight of the brush is reduced, the spring load of the brush can be reduced.
[0103]
In the present invention, the brushes 51 and 52 are used as brushes, which also function as springs and pigtails, and the brushes 51 and 52 are made of copper alloy spring steel (phosphor bronze or beryllium copper in the embodiment). The weight of the brushes 51 and 52, particularly the weight of the brush body 90, is greatly reduced.
[0104]
Thereby, the spring load of the brushes 51, 52 can be greatly reduced as compared with the conventional carbonaceous brush (the brush 123 of FIG. 9), so that the abrasion amount of the brushes 51, 52 can be greatly reduced, and The life of the brushes 51 and 52 can be prolonged by suppressing the trouble caused by the vibration of the brush 52. Therefore, a longer life of the vehicle alternator 1 can be achieved.
[0105]
Next, the effect when the brush holder 63 and the bearing holder 64 of the brush holder 53 are integrated will be described.
As described above, in addition to the sealing effect, the brush holding portion 63 holding the rear bearing 17 (the rear end of the shaft 5) and the brushes 51, 52 via the connection terminals 56, 57 and the brush holding portion 63. And the resin holding member, the positional relationship between the brush holding portion 63 and the bearing holding portion 64 becomes constant, an assembly error between the rear bearing 17 and the bearing holding portion 64, and the brush holding portion 63 and the bearing holding portion. An axial misalignment of the shaft 5 due to an assembly error with the portion 64 can be eliminated.
[0106]
Therefore, the cylindrical gap S in which the sliding portions of the two slip rings 41 and 42 and the two brushes 51 and 52 are present is hermetically sealed by the labyrinth seal 60 on the front end side (the rear end wall side of the pole core 33) ( The outer peripheral side is hermetically sealed (sealed) by a current collecting ring covering portion 65 of the brush holder 53, and the rear end side (the side wall side of the rear housing 12) is the brush holding portion 63 and the bearing holding portion of the brush holder 53. The airtight sealing (sealing) is performed by the sealing member 64. As a result, abrasion powder generated by sliding between the two slip rings 41 and 42 and the two brushes 51 and 52 is not scattered outside through the cylindrical gap S, so that electric components (for example, three-phase Adhesion to the electric components of the rectifier 9, the electronic components of the voltage regulator 10, the three-phase stator coil 32 and the field coil 34) can avoid problems such as deterioration of insulation and poor grounding.
[0107]
Also, as shown in FIG. 6, by forming the shape of the brush body 90 of the brushes 51 and 52 into a ４ arc shape, the contact when the brushes 51 and 52 come into contact with the outer circumferences of the slip rings 41 and 42 is obtained. Since the resultant vector of the pressure is reduced, the structure is such that the force of the contact pressure is not applied to the brush fixing portion 91 mechanically fixed to the connection terminals 56 and 57.
[0108]
Then, as shown in FIG. 6, by providing chamfered extending pieces 93 on both sides in the axial direction of the contact portions 92 of the brushes 51 and 52, the contact portions 92 can move smoothly in the axial direction. It is very easy to assemble the brushes 51 and 52 on the outer circumference of the slip rings 41 and 42 and to detach and disassemble the brushes 51 and 52 from the outer circumferences of the slip rings 41 and 42. As a result, the productivity of the vehicle alternator 1 is improved, so that the product cost of the vehicle alternator 1 can be reduced.
[0109]
Further, the brushes 51 and 52 of the present invention are made of conductive thin elastic material (sheet metal) and can be formed into the shape shown in FIG. 6 only by press working. The hardness of the affected material can be made sufficiently high. Thereby, the life of the brushes 51 and 52 can be extended.
[0110]
Next, the effect of the fixing method (support structure) of the brushes 51 and 52 will be described.
The brush fixing portions 91 and the connection terminals 56 and 57 of the brushes 51 and 52 can be made of different metals in terms of cost, so that the manufacturing cost of the automotive alternator 1 can be reduced. Further, when the brush holder 53 is integrally formed of an electrically insulating resinous material integrally with the connection terminals 56 and 57, the metal characteristics change due to the resin temperature during the insert molding of the connection terminals 56 and 57, Since the abrasion resistance of the brushes 51 and 52 may be reduced, it is necessary to mechanically fix the connection terminals 56 and 57 and the brush fixing portion 91 after insert molding to make an electrical connection therebetween. As a method of fixing the connection terminals 56 and 57 and the brush fixing portion 91, a fixing method such as welding, caulking or the like can be used. However, since the brushes 51 and 52 are made of copper alloy spring steel, performance is not improved. A fixing method using a faston shape (see FIG. 6) which is a minimum space for manufacturing is optimal.
[0111]
(Modification)
In this embodiment, the present invention is applied to the vehicle AC generator (so-called alternator) 1, but the present invention may be applied to a stationary AC generator that supplies power in a building. Further, the present invention may be applied to a generator motor. Then, the shaft 5 may be directly connected to the output shaft of the engine. In this case, no pulley is required. Further, a transmission means such as a gear transmission or a V-belt type continuously variable transmission may be connected between the shaft 5 and the output shaft of the engine. Further, the shaft 5 may be rotationally driven by a drive source such as an internal combustion engine, an electric motor, a water turbine, or a windmill, excluding the vehicle-mounted engine.
[0112]
In this embodiment, a carbonaceous material is used as the material of the slip rings 41 and 42, but a metal powder having a higher strength and a higher conductivity (conductivity) than carbon alone is used as the material of the slip rings 41 and 42. May be. Also in this case, a metallic member (for example, phosphor bronze or beryllium copper, which is spring steel of a copper alloy) is used as a material of the brushes 51 and 52.
[0113]
In this embodiment, the slip rings 41 and 42 are used as the current collecting rings (slip rings). However, a metal current collecting ring such as a copper alloy or stainless steel may be used as the current collecting ring. In this embodiment, the brushes 51 and 52 made of a metallic member are used as metal brushes, but one of the two brushes is made of carbon powder, natural graphite, electric graphite, metal graphite, or the like. A carbonaceous brush may be used. Further, the pigtails may be formed integrally with the brushes 51 and 52, respectively.
[0114]
In this embodiment, the plurality of wing portions 45, the wing fixing portion 46 for supporting them, and the current collecting ring fixing portion 47 in which the slip rings 41 and 42 are insert-molded are integrally formed of a resinous material. May be produced. Alternatively, the plurality of wing portions 45 or the wing fixing portions 46 may be made of a metal material, and may be insert-molded with a current collecting ring and a resin material.
[0115]
In this embodiment, the brush holder (brush holder) 53, the casing 66 of the voltage regulator (regulator) 10, and the bearing holding portion 64 are integrally formed of a resinous member, but they may be manufactured separately. Further, only the brush holder 53 and the voltage adjusting device 10 may be integrally formed.
[0116]
In this embodiment, the centrifugal fan is constituted by the plurality of blades 45 and the blade fixing portion 46 of the blower 7, but the axial flow fan may be constituted by the plurality of blades and the blade fixing portion of the blower. . Note that the current collector 6, the blower 7, and the brush unit 8 may be provided in the front housing 11, that is, on the front end side of the pole core 33 in the housing 2.
In this embodiment, the coil springs 54 and 55 are used as the coil springs, but a leaf spring, an air cushion, rubber, or the like may be used as the coil spring.
[Brief description of the drawings]
FIG. 1 is an enlarged sectional view of a main part structure of an automotive alternator according to the present invention (first embodiment).
FIG. 2 is a sectional view showing the overall structure of the vehicle alternator according to the present invention (first embodiment).
FIG. 3 is a side view showing a brush device, a three-phase rectifier, and a voltage regulator according to the present invention (first embodiment).
FIG. 4 is a sectional view showing the overall structure of the automotive alternator according to the present invention (second embodiment).
FIG. 5 is a side view showing a brush device, a three-phase rectifier, and a voltage regulator according to the present invention (second embodiment).
FIG. 6 is a perspective view showing a current collector and a brush device of the present invention (second embodiment).
FIG. 7 is a side view showing a brush device of the present invention (second embodiment).
FIG. 8 is a sectional view showing a brush holder of the present invention (second embodiment).
FIG. 9 is a sectional view showing the entire structure of a conventional vehicle alternator (conventional example).
[Explanation of symbols]
1 AC generator for vehicles
2 Housing
3 Stator
4 Rotor
5 shaft
6 current collector
7 Blower
8 Brush device
10 Voltage regulator
17 Rear bearing (bearing member)
31 Stator core
32 Stator coil
33 pole core (rotor core)
34 Field coil (rotor coil)
41 Slip ring (collector ring)
42 Slip ring (collector ring)
51 brushes
52 brushes
53 Brush holder (holding member)
54 coil spring
55 coil spring
56 connection terminal (external connection terminal)
57  Connection terminal (external connection terminal)
58 Pigtail
60 Labyrinth Seal
61 First brush holding member (first holding member)
62 Second brush holding member (second holding member)
63 Brush holder
64 Bearing holder
65 collector ring cover
66 Casing
90 Brush body
91 Brush fixing part
92 contacts
93 Extension piece (projection part)
94  Projecting piece
95  Locking piece

Claims (8)

(A) a stator core fixed to the inner surface of the housing;
(B) a stator coil wound around the stator core;
(C) a rotor core that rotates relative to the stator core inside the stator core;
(D) a shaft penetrating the center of the rotor core;
(E) a collector ring provided on the outer periphery of the shaft and electrically connected to the rotor coil ;
(F) a metal brush that slides on the outer peripheral surface of the current collecting ring to supply power to the rotor coil via the current collecting ring, and presses at least the tip of the brush against the outer peripheral surface of the current collecting ring. A brush device having a coil spring ,
(G) a voltage adjusting device having an external connection terminal connected to the brush near the brush device ;
The brush device has a holding member that holds the brush and the coil spring, and a pigtail that electrically connects the brush and an external connection terminal of the voltage regulator using welding means such as welding. Characterized alternator. The alternator according to claim 1,
An alternator , wherein the brush has a U-shaped cross section at the tip . (A) a stator core fixed to the inner surface of the housing;
(B) a stator coil wound around the stator core;
(C) a rotor core that rotates relative to the stator core inside the stator core;
(D) a shaft penetrating the center of the rotor core;
(E) a collector ring provided on the outer periphery of the shaft and electrically connected to the rotor coil;
(F) a metal brush that slides on the outer peripheral surface of the current collecting ring to supply power to the rotor coil via the current collecting ring, and presses at least the tip of the brush against the outer peripheral surface of the current collecting ring. A brush device having a coil spring,
(G) a voltage adjusting device having an external connection terminal connected to the brush near the brush device;
With
The brush device includes a holding member that holds the brush and the coil spring. The brush has a substantially arc-shaped brush body made of spring steel mainly made of a copper alloy, and the brush body holds the brush. It has a brush fixing part protruding to the member side,
The brush fixing portion includes a protruding piece that protrudes in the axial direction from the brush main body, and two elastically deformable locking pieces that are bent on both sides of the protruding piece. The external connection terminal of the voltage regulator is inserted between the stop piece and the external connection terminal of the voltage regulator by the elastic force of the projecting piece and the two locking pieces. An alternator characterized in that it is configured as: The alternator according to claim 3 ,
The alternator includes a bearing member that rotatably supports an end of the shaft,
An electric insulating resin material is used as the material of the holding member, and a casing for holding the external connection terminal of the voltage regulator and a bearing holding portion for holding the bearing member are integrally formed. Alternator. The alternator according to claim 3 or claim 4,
The AC generator includes a blower that generates cooling air for cooling the stator coil and the rotor coil in the housing ,
The holding member is divided into a first holding member and a second holding member that form a labyrinth seal between the blowing device and a foreign matter to prevent a foreign matter from entering a sliding portion between the current collecting ring and the brush. And
The alternator according to claim 1, wherein a joint between the first holding member and the second holding member is provided in the labyrinth seal . The alternator according to any one of claims 1, 3 to 5, wherein the brush is made of a spring steel mainly composed of a copper alloy such as phosphor bronze or beryllium copper, and has its own elastic force. An AC generator, wherein the brush is also a metallic brush that contacts the outer peripheral surface of the current collecting ring . In the alternator according to any one of claims 1, 3 to 6,
The alternator according to claim 1, wherein the collector ring is a carbonaceous collector ring using a carbonaceous member obtained by putting carbon powder obtained by mixing copper and carbon into an annular mold and firing the material . The alternator according to any one of claims 1, 3 to 7 ,
The alternator according to claim 1, wherein the brush has a protruding portion having a chamfered shape extending in an axial direction of the current collecting ring at a tip end portion .

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