JP2001078383A - Ac generator for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an AC generator for vehicle, capable of improving airtightness of a space around a slip ring. SOLUTION: A cylindrical part 4a, covering a slip ring is formed at a frame 4 on the rear side of an AC generator for a vehicle, and at the opening end of the cylindrical part 4a, a brush holder is assembled on the opening end of the cylindrical part 4a via a sealing member. Protruding parts 46, 47, 48 are provided over the entire periphery of a front end 43, a side end 44, and a flat part 45 which form the opening end of the cylindrical part 4a. The protruding parts 46, 47, 48 come into partial contact with the pressure surface of the sealing member, so that the contact surface pressure increases at the surface, and airtightness of a space around the slip ring is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

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

[0002]

2. Description of the Related Art In an automotive alternator, a magnetic flux is generated around a magnetic pole core by passing an exciting current through a field winding provided in a rotor, and this is rotated to generate an electromotive force on a stator. Cause. Then, by rectifying the electromotive force, DC output power is obtained. In general, a slip ring is provided on a rotating shaft of a rotor in order to allow an exciting current to flow through a field winding, and the exciting current flows by bringing a brush of a brush device into contact with the slip ring. As described above, when the brush and the slip ring are brought into contact with each other and an exciting current flows through the sliding surfaces thereof, foreign matter such as water or oil adheres to the sliding surfaces, causing abnormal wear of the brushes. For this reason, a structure has been devised in which foreign matter such as water or oil does not easily enter the periphery of the brush or the slip ring.

For example, in a conventional vehicular alternator disclosed in Japanese Patent Publication No. 5-88058, a peripheral portion of a slip ring is covered by a cylindrical portion formed from a rear frame and a brush holder. There is shown a structure in which a seal member is interposed between these members to improve the airtightness around the slip ring. FIG.
0 is a partial perspective view showing the structure of a cylindrical portion in the conventional vehicular alternator disclosed in Japanese Patent Publication No. 5-88058. In FIG. 20, a cylindrical portion 100a protruding from the rear frame 100 is
It has a tip part 100b and two side ends 100c, and a flat part 100d is formed on the surface of the frame 100 around the root of the cylindrical part 100a. Further, the above-mentioned side end portion 100c and flat portion 100d are formed with a convex portion 100e extending over them. The projecting portion 100e projects toward the sealing member that comes into contact with each of the side end portion 100c and the flat portion 100d.
The protrusion 100e is brought into contact with the seal member to increase the contact surface pressure between the frame 100 and the seal member.
Cylindrical portion 100a where a gap is relatively easily formed between the cylindrical portion 100a
The airtightness is secured at the base.

[0004]

By the way, in the above-mentioned conventional alternator for a vehicle, the protruding portion 100e is formed at the side end portion 10e.
0c and a portion extending over the flat portion 100d, a portion where the cylindrical portion 100a and the sealing member are in contact with each other but the convex portion 100e is not formed, for example, the tip portion 100b of the cylindrical portion 100a Airtightness was not sufficient in some cases. For this reason, there still remains a possibility that foreign matter such as water or oil may enter the periphery of the slip ring from such a location. The same applies to the intrusion of such foreign matter between the brush holder and the seal member, and there has been a demand for a device for improving the airtightness of the entire periphery of the seal member.

The present invention has been made in view of the above points, and an object of the present invention is to provide a vehicle alternator capable of improving the airtightness of a space around a slip ring. .

[0006]

In order to solve the above-mentioned problems, an AC generator for a vehicle according to the present invention protrudes from a rear frame and covers a periphery of a slip ring provided on a rotating shaft of a rotor. A cylindrical portion having an arc-shaped cross section, a brush holder for accommodating a brush that slides on the slip ring, a rear cover for covering electrical components including the brush holder, and pressing and holding between an open end formed by the cylindrical portion and the brush holder. A sealing member formed on at least one of the opening end of the cylindrical portion and the sealing member over substantially the entire circumference of the pressing surface therebetween.

When the sealing member is assembled by pressing the pressing surface, the contact surface pressure at the tip of the convex portion increases, and the convex portion is formed so as to extend over substantially the entire circumference of the pressing surface. Therefore, it is possible to prevent foreign matter such as water or oil from entering the space around the slip ring defined by the cylindrical portion via the pressing surface, and to improve the airtightness of the space around the slip ring. .

Further, the above-mentioned cylindrical portion has a front end facing the rear cover along the rotation axis, and a side end facing the brush holder along the direction in which the brush is pressed against the slip ring. It is desirable that the open end of the cylindrical portion is constituted by the front end portion and the side end portion, and a flat portion formed on the rear surface of the frame and around the cylindrical portion. The sealing member is pressed against the opening end formed by the front end, the side end, and the flat portion to prevent invasion of foreign matter through each of these portions, thereby ensuring the airtightness of the space around the slip ring. Can be enhanced.

Further, the vehicle alternator according to the present invention is in sliding contact with the cylindrical portion having an arc-shaped cross section which protrudes from the rear frame and covers the periphery of the slip ring provided on the rotating shaft of the rotor. A brush holder for accommodating the brush, a rear cover for covering electrical components including the brush holder,
A seal member pressed and sandwiched between the opening end formed by the cylindrical portion and the brush holder, and connected to at least one of the brush holder and the seal member over substantially the entire circumference of a pressing surface therebetween. Ridges are formed. As in the case where the convex portion is formed on either or both of the cylindrical portion and the seal member opposed thereto, the convex portion is formed on either or both the brush holder and the seal member opposed thereto. Is also good. Also in this case, by forming the protruding portion extending over substantially the entire circumference of the pressing surface, it is possible to prevent foreign matter from entering the space around the slip ring through the pressing surface.

Further, when the above-mentioned pressing surface is divided into a first pressing surface having a convex portion and a second pressing surface having no convex portion, the convex portion is formed. It is desirable that the second pressing surface be substantially flat. When the first pressing surface and the second pressing surface are combined and pressed against each other, the tip of the convex portion and the flat surface are opposed to each other. An increase in surface pressure can be achieved uniformly and reliably.

The above-mentioned pressing surface has a portion pressed along the rotating shaft and a portion pressed along the moving direction of the brush, and is pressed along the rotating shaft. It is desirable that the convex portion corresponding to the portion is formed along the pressing direction, and the convex portion corresponding to the portion pressed along the moving direction of the brush is formed along the pressing direction. Since the pressure is applied along the direction in which the convex portions are formed, it is possible to easily increase the surface pressure of the contact portion when the convex portion formed on one pressing surface and the other pressing surface are brought into contact with each other. it can. In addition, by considering both the rotation axis direction and the brush moving direction as the pressing direction, it is possible to improve the airtightness of the space around the slip ring in consideration of the mounting direction of the brush holder, the seal member, the rear cover, and the like. it can.

[0012]

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 a vehicle alternator according to one embodiment. 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, a regulator 7, a rectifying device 8, 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 field winding 31 formed by winding an insulated copper wire in a cylindrical and concentric manner, each of which has a length of 6 mm.
The rotation axis 33 is provided by the pole core 32 having the claw portions.
Has a structure sandwiched from both sides. Also,
A cooling fan 35 for discharging the cooling air sucked in from the front side in the axial direction and the radial direction is attached to the 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 the radial direction is attached to an end face of the pole core 32 on the rear side by welding or the like. In the vicinity of the rear end of the rotating shaft 33, two slip rings 37 electrically connected to both ends of the field winding 31,
38 are formed, and these slip rings 37,
Power is supplied from the brush device 5 to the field winding 31 via 38.

The frame 4 houses the stator 2 and the rotor 3, and the rotor 3 is supported rotatably 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. Also, on the rear side frame 4,
A cylindrical portion 4a having an arc-shaped cross section that covers the outer circumferences of the two slip rings 37 and 38 is formed. The detailed structure of the cylindrical portion 4a and its surroundings will be described later.

The brush device 5 includes two slip rings 3
Two brushes 51 and 52 slidingly contacting each of 7 and 38
And a slip ring 37,
And a rubber seal member 54 for improving the airtightness of a space formed around the periphery 38. The seal member 54 is pressed and held by the cylindrical portion 4 a and the brush holder 53, and is pressed and held by the rear cover 6 toward the brush holder 53 and the cylindrical portion 4 a of the frame 4. The detailed structure of the seal member 54 will be described later.

The rear cover 6 is attached so as to cover various electric components such as the brush device 5, the regulator 7, and the rectifying device 8 which are attached to the outside of the frame 4, and protects them from foreign matters.

AC generator 1 for vehicle having the above-described configuration
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, the respective claws of the pole core 32 are excited, and a three-phase AC voltage can be generated in the stator winding 23. A predetermined DC current is extracted from the rectifier 8.

Next, the detailed structure of the cylindrical portion 4a formed on the rear frame 4 of the vehicle alternator 1 of this embodiment and the seal member 54 included in the brush device 5 will be described. FIG. 2 is a perspective view showing the structure of the cylindrical portion 4a formed on the rear frame 4. As shown in FIG. The cylindrical part 4 shown in FIG.
a is for covering and protecting the slip rings 37 and 38 formed near one end of the rotating shaft 33. The shape of the cross section perpendicular to the rotating shaft 33 has a central angle of approximately (3/3).
4) It is formed in an arc shape of × 2π.

The cylindrical portion 4a has a tip 43 facing the rear cover 6 along the rotation shaft 33, and two sides facing the brush holder 53 along the direction in which the brushes 51, 52 are pressed against the slip rings 37, 38. And an end 44. The cylindrical portion 4 on the surface of the rear side frame 4
a flat portion 45 is formed around the front end portion 43 and the side end portion 44 of the cylindrical portion 4a.
5, the opening end of the cylindrical portion 4a is formed. At the opening end, a projection is formed over substantially the entire circumference. Specifically, a convex portion 46 extending in a direction parallel to the rotation shaft 33 is formed on the distal end portion 43. The side end 44 is formed with a convex portion 47 extending in a direction parallel to the moving direction of the brushes 51 and 52. The flat portion 45 has a convex portion 48 extending in a direction parallel to the rotation shaft 33.
These convex portions 46, 47, 48 are formed at the opening end of the cylindrical portion 4a so as to be continuous as a whole.

FIG. 3 is a perspective view showing the detailed structure of the brush device 5. As described above, the brush device 5 includes the brush holder 53 that accommodates the brushes 51 and 52, and the seal member 54 formed of a rubber material to increase the airtightness of the space around the slip rings 37 and 38. ing. With the seal member 54 attached to the brush holder 53, the brushes 51 and 52 are
8, the brush device 5 is assembled.
Thereby, the seal member 54 is formed by the brush holder 53.
Is pressed against the side end 44 of the cylindrical portion 4a. After that, the rear cover 6 is assembled and the entire brush device 5 is fastened to the front side (the side to which the pulley 20 is attached) along the rotating shaft 33, so that the sealing member 54 is in contact with the distal end 43 of the cylindrical portion 4a. It is pressed against the flat part 45 of the frame 4.

As described above, each of the distal end portion 43, the side end portion 44, and the flat portion 45 constituting the open end portion of the cylindrical portion 4a is pressed against the opposing surfaces of the seal member 54. Convex portions 46, 4 so as to be continuous over the entire circumference
7, the projections 46, 47, and 47 are formed on the pressing surface 54a of the seal member 54, as shown in FIG.
The tips of the 48 partially contact, and the contact surface pressure at this portion increases. Accordingly, the pressing surface of the sealing member 54 corresponding to the portion where the contact surface pressure is high is easily deformed, and the pressing surfaces of the cylindrical portion 4a and the sealing member 54 are easily partially adhered to each other, so that the cylindrical portion 4a It is possible to improve the airtightness of the space around the slip rings 37 and 38 defined by the above.

In particular, as described above, the convex portions 46, 47,
48 is formed on the cylindrical surface 4a side pressing surface (tip portion 43,
Each of the side end portion 44 and the flat portion 45 corresponds to this, and corresponds to the first pressing surface in the present invention), and the pressing surface 54a on the side of the seal member 54 on which the convex portion is not formed (the fourth pressing surface in the present invention). (Corresponding to 2 pressing surfaces)
By making the pressing surface 54a substantially flat, the above-mentioned projections 46, 47, 48 are pressed against this flat surface, whereby a uniform airtight state with no gap can be achieved.

In the brush device 5 of this embodiment, a similar device is also provided between the brush holder 53 and the seal member 54 in order to improve the airtightness of the space around the slip rings 37 and 38.

FIG. 5 is a front view of the seal member 54,
3 shows the shape of the seal member 54 viewed from the side of the brush holder 53 shown in FIG. FIG. 6 shows V
It is an I-VI line sectional view. As shown in FIGS. 3, 5, and 6, the seal member 54 includes a first seal portion 151 sandwiched between the distal end portion 43 of the cylindrical portion 4a and the rear cover 6, and a side end portion 44 of the cylindrical portion 4a. A second seal 152 sandwiched between the brush holder 53 and the brush cover 53; and a third seal 153 sandwiched between the brush holder 53 and the rear cover 6. The first seal portion 151 has a groove 154 having a pressing surface at the bottom opposed to the distal end portion 43 of the cylindrical portion 4a, and the pressing surface 54 of the groove 154.
FIG. 4 shows a corresponding relationship between a and the tip portion 43 of the cylindrical portion 4a.

Further, the second seal portion 152 has a cylindrical portion 4
a groove 1 having a pressing surface at the bottom facing the side end portion 44 of FIG.
55 and projections 156 and 157 formed on the pressing surface facing the brush holder 53. One convex part 15
The brush 5 is located at a position facing the vicinity of the side surface of the front surface (the surface from which the brushes 51 and 52 protrude) of the brush holder 53.
The other protrusion 157 is formed so as to protrude along the rotation shaft 33 at a position facing the lower front surface of the brush holder 53. I have. Further, the third seal portion 153 has a convex portion 158 formed so as to protrude along the rotation shaft 33 at a position facing the vicinity of the outer periphery of the upper surface (the surface facing the rear cover 6) of the brush holder 53. are doing. Each of the above-mentioned convex portions 156, 157, and 158 is formed so as to be entirely continuous with the pressing surface between the brush holder 53 and the seal member 54.

As described above, the sealing member 54 has the convex portion 1 that extends over the entire circumference of the pressing surface with the brush holder 53.
Since 56, 157, and 158 are formed, their tips are partially in contact with the pressing surface of the brush holder 53, and the contact surface pressure at these portions can be increased. Therefore, the part where the contact surface pressure is high is easily deformed,
Slip rings 37, 38 including brushes 51, 52
The airtightness of the surrounding space can be further improved.

The present invention is not limited to the above embodiment, and various modifications can be made within the scope of the present invention. For example, in the above-described embodiment, the cross-sectional shapes of the convex portions 46, 47, and 48 formed at the opening end of the cylindrical portion 4a are simple rectangular shapes, but the cross-sectional shapes can be arbitrarily changed. For example, the tip may have an arc shape as shown in FIG. 7, or a triangular shape as shown in FIGS.

In the above-described embodiment, the cylindrical portion 4a
The projections 46, 47 and 48 are formed on the cylindrical portion 4a on the contact surface between the sealing member 54 and the sealing member 54.
As shown in FIG.
4b may be formed.

Similarly, in the above-described embodiment, the convex portions 156, 157, and 158 formed on the pressing surface of the seal member 54 facing the brush holder 53 have a substantially rectangular shape. Can be changed. For example, the tip may have an arc shape as shown in FIG. 12, or a triangular shape as shown in FIG. Further, since the sealing member 54 is formed using a rubber material, the cylindrical portion 4a formed by aluminum die casting or the like is used.
A more complicated shape is easily formed, and as shown in FIGS. 14 to 17, two (or three or more) convex portions such as a rectangular shape, an arc shape, and a triangular shape are formed on the pressing surface of the seal member 54.
They may be formed side by side.

In the above-described embodiment, the protrusions 156, 157, and 158 are formed on the seal member 54 on the contact surface between the seal member 54 and the brush holder 53.
These protrusions may be formed on the brush holder 53.

The seal member 54 and the brush holder 53
The convex portions may be formed on both of the pressing surfaces, or the convex portions may be formed on both of the pressing surfaces of the cylindrical portion 4a and the seal member 54. In these cases, for example, as shown in FIG.
It is necessary to make the tips of two (or three or more) adjacent protrusions contact the pressing surface of the other party at different positions.

The side end 44 of the cylindrical portion 4a (the tip 4
3) and the groove 1 of the sealing member 54 facing the same.
In the case where the protrusions are formed in the plurality of protrusions 55, as shown in FIG.
4c, and the plurality of convex portions 54c may be brought into partial contact with the side end portion 44 and its periphery.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating an overall configuration of a vehicle alternator according to an embodiment.

FIG. 2 is a perspective view showing a structure of a cylindrical portion formed on a rear frame.

FIG. 3 is a perspective view showing a detailed structure of the brush device 5;

FIG. 4 is a diagram illustrating a cross-sectional shape of a protrusion provided on a cylindrical portion.

FIG. 5 is a front view of the seal member.

FIG. 6 is a sectional view taken along line VI-VI shown in FIG. 5;

FIG. 7 is a cross-sectional view showing a modification of a projection provided on a cylindrical portion.

FIG. 8 is a cross-sectional view showing a modification of a projection provided on a cylindrical portion.

FIG. 9 is a cross-sectional view showing a modification of a projection provided on a cylindrical portion.

FIG. 10 is a cross-sectional view showing a modification of a projection provided on a cylindrical portion.

FIG. 11 is a cross-sectional view showing a convex portion formed on a pressing surface of the seal member facing the cylindrical portion.

FIG. 12 is a cross-sectional view illustrating a modification of a projection provided on a seal member.

FIG. 13 is a cross-sectional view illustrating a modified example of a projection provided on a seal member.

FIG. 14 is a cross-sectional view showing a modified example of a projection provided on a seal member.

FIG. 15 is a cross-sectional view showing a modified example of a projection provided on a seal member.

FIG. 16 is a cross-sectional view showing a modified example of a projection provided on a seal member.

FIG. 17 is a cross-sectional view showing a modified example of a projection provided on a seal member.

FIG. 18 is a cross-sectional view illustrating a modified example of a protrusion provided on each of two opposing pressing surfaces.

FIG. 19 is a cross-sectional view of a plurality of protrusions formed on the seal member along different directions.

FIG. 20 is a perspective view showing a structure of a cylindrical portion formed on a frame of a conventional automotive alternator.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Vehicle alternator 2 Stator 3 Rotor 4 Frame 4a Cylindrical part 5 Brush device 6 Rear cover 37, 38 Slip ring 43 Tip part 44 Side end part 45 Flat part 46, 47, 48, 156, 157, 157 Convex part 53 brush holder 54 sealing member

Continued on the front page F term (reference) 5H605 AA02 AA03 BB03 BB11 DD07 DD17 DD31 EA21 EB10 EB12 FF08 5H613 AA01 AA02 AA06 BB02 BB05 BB15 BB25 GA01 GB02 GB09 GB18 PP03 SS02 5H619 AA00 BB10

Claims (5)

[Claims] A cylindrical portion having an arc-shaped cross section that protrudes from a frame on a rear side and covers a periphery of a slip ring provided on a rotating shaft of a rotor; a brush holder for accommodating a brush that slides on the slip ring; A rear cover that covers an electrical component including the brush holder; a seal member pressed and held between the brush holder and an open end formed by the cylindrical portion; and an open end of the cylindrical portion and the seal member. Characterized in that at least one of them has a protruding portion which extends over substantially the entire circumference of the pressing surface therebetween. 2. The brush according to claim 1, wherein the cylindrical portion has a tip portion facing the rear cover along the rotation axis, and a side facing the brush holder along a direction in which the brush is pressed against the slip ring. An open end of the cylindrical portion is constituted by the front end portion and the side end portion, and a flat portion formed around the cylindrical portion on the rear surface of the frame. An alternator for a vehicle, comprising: 3. A cylindrical portion having an arc-shaped cross section which protrudes from a frame on the rear side and covers a periphery of a slip ring provided on a rotating shaft of a rotor, a brush holder for accommodating a brush slidably contacting the slip ring, A rear cover that covers an electrical component including the brush holder; and a seal member pressed and held between the brush holder and an open end formed by the cylindrical portion. At least one of the brush holder and the seal member An alternating current generator for a vehicle, wherein a convex portion is formed so as to extend over substantially the entire circumference of the pressing surface therebetween. 4. The method according to claim 1, wherein the first pressing surface on which the convex portion is formed and the second pressing surface on which the convex portion is not formed include: 2
An alternator for a vehicle, wherein the pressing surface is substantially flat. 5. The pressing surface according to claim 1, wherein the pressing surface includes a portion pressed along the rotation axis,
The brush has a portion that is pressed along the moving direction of the brush, and the convex portion is formed in a direction along the rotation axis for a portion that is pressed along the rotation axis, An alternator for a vehicle, wherein a portion to be pressurized along the moving direction of the brush is formed along the moving direction of the brush.