JP2002125343A - Vehicle ac generator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vehicle AC generator which can surely discharge wear powder produced in the neighborhoods of slip rings. SOLUTION: Wear powder discharge paths 85, having openings 84 in a direction of a rotary shaft and wear powder discharge paths 87 which have openings 86 in radial directions of the rotary shaft are formed in a rear side frame 4 of a vehicle AC generator.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle alternator mounted on a passenger car, a truck and the like.

[0002]

2. Description of the Related Art Conventionally, in an automotive alternator, water or oil or the like is prevented from entering a slip ring formed near one end of a rotating shaft of a rotor, and a brush slides on the slip ring. A brush holder and a slip ring cover assembled via a seal member are used to discharge abrasion powder generated by the brush. For example, Japanese Patent Application Laid-Open No. 9-182353 discloses a vehicle alternator having a wear powder discharge hole formed in a flange portion of a rear frame. In this vehicle alternator, the brush device is assembled with the labyrinth packing interposed between the brush holder and the rear cover to increase the airtightness around the slip ring, prevent foreign matter from entering, and slide the brush on the slip ring. Brush abrasion powder generated as a result is discharged from the abrasion powder discharge hole.

[0003]

However, in the conventional vehicular alternator disclosed in the above-mentioned publication, since only a single abrasion powder discharge hole is formed, highly viscous mud or the like is removed. If adhered, the abrasion powder discharge holes may be closed, and the abrasion powder of the brush may not be discharged. When the abrasion powder discharge hole is closed, the flow of air around the slip ring is interrupted, and the temperature of the slip ring and the brush rises. For this reason, the exciting current of the rotor decreases, leading to a decrease in the power generation capacity of the vehicle alternator, and some measures are required.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an automotive alternator capable of reliably discharging brush abrasion powder generated around a slip ring. It is in.

[0005]

In order to solve the above-mentioned problems, a vehicle alternator according to the present invention accommodates a brush that slides on a slip ring and covers an outer peripheral portion of the slip ring with a slip ring cover. A first wear powder discharge passage having a first opening that opens in the axial direction of the rotating shaft and a second wear that has a second opening that opens in the radial direction of the rotating shaft; A powder discharge passage is formed, respectively. By providing two types of abrasion powder discharge passages in which the directions of the openings are different, the probability that these two openings are simultaneously closed can be significantly reduced. Therefore, through at least one opening,
Abrasion powder of the brush generated around the slip ring can be reliably discharged.

Further, it is preferable that a foreign matter intrusion preventing portion for preventing foreign matter from entering the internal space through the first opening is further provided around the first opening. Normally, a vehicle alternator is mounted on a vehicle such that the rotation axis is in a horizontal direction. Therefore, depending on the positional relationship, a wall surface or the like around the first opening along the rotation axis may be provided. In some cases, foreign matter such as water can easily enter, but by forming a foreign matter intrusion prevention portion around the first opening, such foreign matter can be effectively prevented.

The above-described rotor has a cooling fan on the side where the slip ring is formed, and sets the area of the second opening smaller than the area of the first opening. It is desirable that the second opening is formed at a position closer to the fan than the first opening. Close to fans,
By making the area of the second opening where a large negative pressure is generated smaller than the area of the first opening, the discharging ability of the brush wear by the first abrasion powder discharge passage and the second abrasion powder discharge passage Can be set close to or substantially equal to each other, so that the brush wear powder in the internal space can be discharged in a well-balanced manner through the two wear powder discharge passages. As a result, the amount of brush abrasion powder that is not completely discharged and accumulated near each of the abrasion powder discharge passages can be made substantially the same. Accumulation can be prevented.

Further, it is desirable that the above-mentioned second opening is formed at a position substantially opposite to the ceiling when mounted on the vehicle. By arranging the second opening formed in the radial direction substantially on the opposite side (substantially the ground side) from the top direction, it is possible to prevent foreign matter from entering the internal space through the second opening. . In addition, foreign matter such as highly viscous mud
Even if it adheres to the vicinity of the opening, the foreign matter is shaken off by the vibration of the vehicle alternator itself or the vibration transmitted from the engine, so that the second opening is prevented from being blocked. can do.

It is preferable that the first and second abrasion powder discharge passages are formed integrally with the frame holding the rotor. There is no increase in the number of parts due to integral molding.
Manufacturing costs, assembling costs, etc. can be reduced.
Further, it is desirable that the above-mentioned second wear powder discharge passage is formed at a position offset from the first wear powder discharge passage in the circumferential direction of the rotating shaft. This can further reduce the probability that each opening of the first and second wear powder discharge passages will be closed at the same time, so that the wear powder of the brush generated around the slip ring can be more reliably discharged. Will be possible.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A vehicle AC generator according to an embodiment of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a diagram showing the overall configuration of the vehicle alternator. The automotive alternator 1 shown in FIG. 1 includes a stator 2, a rotor 3, a frame 4, a brush device 5, a rear cover 6, and the like.

The stator 2 includes a stator core 22, a three-phase stator winding 23, and an insulator 24 for electrically insulating the stator core 22 and the stator winding 23 from each other.
The rotor 3 has a structure in which a field winding 31 in which an insulated copper wire is wound cylindrically and concentrically is sandwiched from both sides through a rotating shaft 33 by pole cores 32 each having six claws. have. Further, a cooling fan 35 for discharging the cooling air sucked from the front side in the axial direction and the radial direction is attached to an end face of the pole core 32 on the front side by welding or the like. Similarly,
A cooling fan 36 for discharging the cooling air sucked from the rear side in a radial direction is attached to an end face of the pole core 32 on the rear side by welding or the like. Also, the rotating shaft 33
In the vicinity of the rear end of the motor, two slip rings 37 and 38 electrically connected to both ends of the field winding 31 are formed. Power is supplied to the field winding 31.

The frame 4 houses the stator 2 and the rotor 3, and the rotor 3 is supported so as to be rotatable about a rotation shaft 33, and the outer periphery of the pole core 32 of the rotor 3. Is fixed to the stator 2 disposed with a predetermined gap therebetween. Further, the frame 4 has a discharge window 42 for cooling air at a portion facing the stator winding 23 protruding from the axial end face of the stator core 22, and has a suction window 41 at the axial end face.

The brush device 5 includes two slip rings 3
Two brushes 51 and 52 slidingly contacting each of 7 and 38
, A slip ring cover 54 that covers the outer circumference of the slip rings 37 and 38 together with the brush holder 53, and a slip ring 37 that is disposed at the axial ends of the brush holder 53 and the slip ring cover 54 during assembly. And two seal members 55 and 56 for improving the airtightness of a space formed around the periphery 38. These seal members 55 and 56 are formed of a plate-like rubber material.

The rear cover 6 includes a brush device 5, a rectifying device, and an IC mounted on the outside of the frame 4 on the rear side.
Mounted over the regulator to protect them from foreign matter. The rear cover 6 is formed of a resin material, and has a plurality of suction windows formed along concentric circles, three mounting holes through which three bolts 43 mounted on the frame 4 penetrate, and these three holes. And an insert fitting embedded in a region including the mounting hole. The detailed structure of the brush device 5, the frame 4 near the brush device 5, and the rear cover 6 will be described later.

Vehicle alternator 1 having the above structure
When a rotational force from an engine (not shown) is transmitted to the pulley 20 via a belt or the like, the rotor 3 rotates in a predetermined direction. In this state, by applying an excitation voltage to the field winding 31 of the rotor 3 from the outside, each claw of the pole core 32 is excited, and a three-phase AC voltage can be generated in the stator winding 23. From the output terminal 10, a predetermined direct current is extracted.

Next, the detailed structure of the brush device 5 and the rear cover 6 will be described. FIG. 2 shows a brush holder 53.
FIG. 6 is a perspective view of the brush device 5 showing an assembled state of the brush device 5 and a slip ring cover 54. FIG. 3 shows a brush 51,
FIG. 4 is a perspective view of a brush holder 53 before assembling 52.
Is a perspective view of the slip ring cover 54. FIG.

Brush holder 53 made of thermosetting resin
Is a first storage unit 15 for storing the brushes 51 and 52.
0 and a second storage portion 151 for storing the pigtail are provided. The box portion 152 has a slip ring 37, 38 side to increase the surface area.
A thick portion 153 is formed in a concave curved shape along the outer peripheral surfaces of the slip rings 37 and 38. Brush holder 5
3 are end faces 154 on both sides along the radial direction of the box 152
Then, the terminals 155 on the positive electrode side and the negative electrode side made of a metal plate are protruded and are integrally molded. In addition, concave portions 156 having a rectangular cross section are formed at both ends in the radial direction of the concave curved surface of the thick portion 153 over the entire length in the axial direction. Each of the two end faces along the
7 are formed.

The slip ring cover 54 includes a rotating shaft 33.
Is provided to cover and protect slip rings 37, 38 formed on one end side of the cylindrical body, and has a shape obtained by removing about 1/4 of the circumference of the cylindrical body, and has a radial cross-sectional shape of a circle. About 3
/ 4. Therefore, the slip ring cover 54
Is constituted by a substantially cylindrical peripheral wall 160 made of a resin material (for example, made of nylon) having a circumference of about ／. A relatively thin V-shaped convex portion 161 extending in the axial direction is formed at both ends in the circumferential direction of the peripheral wall 160 so as to be fitted with the concave portion 156 of the brush holder 53. In addition, outside the V-shaped convex portion 161,
A hook-shaped projection 162 that engages with the projection 157 of the brush holder 53 is formed.

The brush device 5 includes a slip ring cover 5
4 is fixed, the concave portion 156 of the brush holder 53 is slid and fitted to the V-shaped convex portion 161 of the slip ring cover 54 while being assembled.
In the brush device 5, the axial length of each of the brush holder 53 and the slip ring cover 54 is set so that a step does not occur on both end surfaces in the axial direction in the assembled state. For example, as shown in FIGS. 2 and 3, the box portion 152 and the thick portion 1 of the brush holder 53 are provided.
53 and the slip ring cover 5
4 are formed on the same plane without any step. Further, at least the end face of the thick part 153 of the brush holder 53 on the frame 4 side and the end face of the slip ring cover 54 on the frame 4 side are formed on the same plane with no step.

Next, the detailed structure of the rear cover 6 will be described. FIG. 5 is a plan view of the rear cover 6 and shows a shape as viewed from the frame 4 side in which the brush device 5 and the like are stored. The rear cover 6 includes a substantially circular flat portion 64 and a cylindrical portion 65 extending in the axial direction around the flat portion 64. The rear cover 6 has an opening formed at one end of the cylindrical portion 65. The brush device 5 and the like are accommodated to protect them. A maze structure is formed in the flat portion 64 by a groove 66 having one or more bent shapes in a region facing the brush device 5 with the seal member 56 interposed therebetween.

FIG. 6 is an enlarged view near the area where the maze structure is formed. FIG. 7 is a partial perspective view in the vicinity of the maze structure, and shows the correspondence with the brush device 5 and the like. In FIG. 6, the area 69 is hatched.
Is a region covered by the seal member 56, and the ventilation passage 67 is formed by the space of the maze structure surrounded by the groove 66 formed in the rear cover 6 and the seal member 56 arranged so as to close the opening of the groove 66. Is formed. The ventilation passage 67 connects the internal space sandwiched between the brush holder 53, the slip ring cover 54 and the slip rings 37 and 38, and the space inside the rear cover 6 outside the brush device 5. The internal space is kept airtight by the brush device 5 and two seal members 55 and 56 disposed on both end surfaces in the axial direction. Then, the air sucked in from the opening 68 formed at one end of the ventilation passage 67 passes through the ventilation passage 67 to the internal space, and the internal space is ventilated.

Incidentally, the vehicle alternator 1 of the present embodiment is formed in a direction along the rotating shaft 33 in order to discharge the air guided into the internal space near the slip rings 37 and 38 described above. And a second opening formed in a radial direction. Next, these two types of openings will be described in detail.

FIG. 8 is a front view showing the outer shape of the rear frame 4. FIG. 9 is a partially enlarged view of the vicinity of the center of the frame 4 shown in FIG. FIG. 10 is a front view showing the inner shape of the frame 4 on the rear side. In the rear frame 4, a plurality of suction windows 41 for sucking cooling air into the inside of the frame 4 are opened on substantially the same circumference by the rotation of the rear cooling fan 36 fixed to the rotor 3. ing. At the rear end of the rear frame 4, the box 152 of the brush holder 53, the frame 4 side end of the thick portion 153, and the frame 4 side end of the slip ring cover 54 sandwich the seal member 55. A flange 80 is formed in a contact area. In addition, when the brush device 5 is assembled, the terminal 1 on the negative electrode side is screwed to a position where the terminal 155 on the negative electrode side protruding from the side surface of the brush holder 53 is arranged.
A pedestal 82 for electrically connecting 55 and the like to the frame 4 and fixing the frame is formed.

The rotating frame 3 is provided on the rear frame 4.
The first abrasion powder discharge has an opening 84 that opens to the rear cover 6 at a position that is substantially 90 ° with respect to the ceiling direction when the vehicle alternator 1 is assembled to the vehicle and is oriented along 3. Passage 85 and direction almost opposite to the ceiling direction (almost ground direction, exactly 15 ° shifted from the ground direction)
Abrasion powder discharge passage 8 having an opening 86 opened to the outside
7 are formed. As described above, in the present embodiment, the second wear powder discharge passage 87 is replaced by the first wear powder discharge passage 85.
Is formed at a position offset in the circumferential direction of the rotating shaft 33 from the position.

FIG. 11 is an enlarged sectional view including one abrasion powder discharge passage 85 having an opening 84 in a direction along the rotation axis 33. FIG. 11 is a sectional view including the O-XI line shown in FIG. The state where the device 5, the rear cover 6, and the like are assembled is shown. In FIG. 11, dotted arrows indicate the flow of air sucked into the internal space near the slip rings 37 and 38 and discharged through the abrasion powder discharge passage 85.

The opening 84 of the abrasion powder discharge passage 85 is divided into three substantially equal sizes, and an outer wall 88 as a convex foreign matter intrusion preventing portion is formed so as to surround the opening 84. The outer wall portion 88 is provided at least with the rear end surface of the frame 4 on the rear side from the top and the slip ring cover 5.
4 to prevent intrusion of foreign matter along the line 4, and is formed so as to include a region around the opening 84 and facing the top direction and the slip ring cover 54.

FIG. 12 shows the opening 8 in the direction along the radial direction.
FIG. 10 is an enlarged cross-sectional view including the other abrasion powder discharge passage 87 having a cross-section 6 and a cross-section including the line XXII shown in FIG. In FIG. 12, the dotted arrows indicate the flow of air sucked into the internal space near the slip rings 37 and 38 and discharged through the abrasion powder discharge passage 87.

The abrasion powder discharge passage 87 is formed by closing a groove (recess) formed in a part of the inner end of the rear side frame 4 along the radial direction by disposing a bearing 89 on the opening side. It is configured. The opening 86 of the wear powder discharge passage 87 is formed by the opening 84 of the wear powder discharge passage 85 described above.
The area is set to about 1/3 as compared with. The opening 86 of the abrasion powder discharge passage 87 is provided at a position closer to the cooling fan 36 than the opening 84 of the abrasion powder discharge passage 85 described above.
, And the negative pressure generated when the cooling fan 36 is rotated is set to be larger near the opening 86 having a smaller area than near the opening 84 having a larger area. .

As described above, in the vehicle alternator 1 of the present embodiment, since two kinds of abrasion powder discharge passages 85 and 87 having different opening directions are formed, foreign matters such as muddy water are formed inside the rear cover 6. , The probability that these two openings 84 and 86 are closed at the same time can be greatly reduced. Therefore, the brush abrasion powder generated around the slip rings 37 and 38 can be reliably discharged through at least one opening. In particular, the rotating shaft 3
Since the outer wall portion 88 as a foreign matter intrusion prevention portion is formed around one opening 84 along 3, foreign matter is formed along the rear end surface of the rear frame 4 and the outer peripheral surface of the slip ring cover 54. Intrusion into the opening 84 can be effectively prevented.

Further, the area of the opening 86 near the rear cooling fan 36 in the radial direction where a large negative pressure is generated is made smaller than the area of the opening 84 along the rotating shaft 33 so that the opening can be reduced. Abrasion powder discharge passage 8 connected to section 86
7 and the discharge ability of the brush wear powder by the wear powder discharge passage 85 connected to the opening 84 can be made close to or substantially the same.
The brush wear powder in the internal space is discharged into two wear powder discharge passages 85,
87 can be discharged in a well-balanced manner. As a result, the amount of brush abrasion powder that is not completely discharged and accumulates in the vicinity of each of the abrasion powder discharge passages 85 and 87 can be made substantially the same. Can be prevented from being concentratedly deposited.

By arranging the radial opening 86 substantially opposite to the ceiling (substantially the ground), it is possible to prevent foreign matter from entering the internal space through the opening 86. In addition, even if foreign matter such as highly viscous mud adheres to the vicinity of the opening 86, the foreign matter is easily shaken off by vibration of the vehicle alternator 1 itself or vibration transmitted from the engine. 86
Can be prevented from being blocked.

Further, the above-mentioned wear powder discharge passages 85 and 87
By integrally molding as a part of the frame 4, the number of parts can be reduced, so that manufacturing cost, assembling cost, and the like can be reduced. Further, since the two openings 84 and 86 are formed, it is easy to increase the area of the entire opening as compared with the related art, and the brush temperature is reduced by increasing the discharging capability of air and brush abrasion powder. be able to.

Further, the formation position of the second wear powder discharge passage 87 is offset from the formation position of the first wear powder discharge passage 85 in the circumferential direction of the rotating shaft 33, that is, shifted in the radial direction. Accordingly, the probability that the openings of these two types of wear powder discharge passages 85 and 87 are simultaneously closed can be further reduced.

[Brief description of the drawings]

FIG. 1 is a diagram showing an overall configuration of a vehicle alternator.

FIG. 2 is a perspective view of the brush device showing an assembled state of a brush holder and a slip ring cover.

FIG. 3 is a perspective view of a brush holder before a brush is assembled.

FIG. 4 is a perspective view of a slip ring cover.

FIG. 5 is a plan view as viewed from the inside of the rear cover.

FIG. 6 is a partially enlarged view of a rear cover near a region where a maze structure is formed.

FIG. 7 is a partial perspective view near a maze structure.

FIG. 8 is a front view showing the outer shape of the rear frame.

FIG. 9 is a partially enlarged view of the vicinity of the center of the frame shown in FIG. 8;

FIG. 10 is a front view showing the inner shape of the rear frame.

FIG. 11 is an enlarged sectional view including one wear powder discharge passage having an opening in a direction along the rotation axis.

FIG. 12 is an enlarged cross-sectional view including the other abrasion powder discharge passage having an opening in a direction along a radial direction.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Vehicle alternator 2 Stator 3 Rotor 4 Frame 5 Brush device 6 Rear cover 37, 38 Slip ring 51, 52 Brush 53 Brush holder 54 Slip ring cover 55, 56 Seal member 80 Flange 84 Opening (axial direction) 85 Wear powder discharge passage (axial direction) 86 Opening (radial direction) 87 Wear powder discharge passage (radial direction) 88 Outer wall portion

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 5H605 AA03 BB03 BB11 CC01 CC02 CC07 DD34 EB10 EB12 EC08 GG04 5H613 AA03 BB03 BB15 BB27 GA01 GB02 GB09 GB18 KK03 KK05 PP03 SS03

Claims (6)

[Claims] 1. A vehicle alternator having a brush device for accommodating a brush that slides on a slip ring provided on a rotating shaft of a rotor and covering an outer peripheral portion of the slip ring with a slip ring cover. A first opening that opens in the axial direction of the shaft, and discharges wear powder generated by sliding between the slip ring and the brush from an internal space formed by the slip ring cover to the outside; An internal space formed by the slip ring cover, having a wear powder discharge passage, and a second opening that opens in a radial direction of the rotating shaft, wherein wear powder generated by sliding between the slip ring and the brush is formed by the slip ring cover. And a second abrasion powder discharge passage for discharging from the vehicle to the outside. 2. The device according to claim 1, further comprising a foreign matter intrusion preventing portion around the first opening to prevent foreign matter from entering the internal space through the first opening. AC generator for vehicles. 3. The rotor according to claim 1, wherein the rotor has a cooling fan on the side where the slip ring is formed, and the area of the second opening is reduced by the first opening. An alternator for a vehicle, wherein the second opening is formed at a position closer to the fan than the first opening, while being set smaller than the area of the portion. 4. The alternator for a vehicle according to claim 1, wherein the second opening is formed at a position substantially opposite to the ceiling when mounted on the vehicle. 5. The frame according to claim 1, further comprising a frame for holding the rotor, wherein the first wear powder discharge passage and the second wear powder discharge passage are integrally formed with the frame. An alternator for vehicles. 6. The second wear powder discharge passage according to claim 1, wherein the second wear powder discharge passage is formed at a position offset in a circumferential direction of the rotating shaft from the first wear powder discharge passage. An alternator for a vehicle, comprising: