JPH01274643A - Ac generator - Google Patents

Abstract

PURPOSE:To prevent the penetration of water and oil into an apparatus by forming an axially longer one out of a brush holder cover and a slip ring outer peripheral cover from thermoplastic resin and by forming irregularities at both axial ends into an integral body through hot working thereof to correct differences in level. CONSTITUTION:A brush 16 in sliding contact with a slip ring 7 fastened to a shaft 4 is held by a brush holder 18, and its outside together with a pigtail 17 is covered with a cover 28. Also, a slip ring cover 19 covering the outer periphery of said slip ring 7 is provided, and both axial ends of said covers 28 and 19 are provided with irregularities. An axially longer one of said covers 28, 19 is formed from thermoplastic resin, and both covers are formed into an integral body through hot working to eliminate differences in level. Then, a rear cover 21 is fastened via sealing members 24, 25 to fix said covers 28 and 19. Thus, sealing properties of an apparatus are secured and penetration of water and oil is prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an alternating current generator suitable for use in a vehicle, and particularly relates to a seal M structure around a slip ring.

[Prior Art] In vehicle alternators, in order to prevent water, oil, etc. from entering the area around the slip ring, a brush holder and a slip ring cover that are assembled via a sealing member are conventionally used to prevent the slip ring from entering the area around the slip ring. protects the outer periphery of the

However, the brush holder and slip ring cover are
The outer periphery of the slip ring is assembled so as to cover it from the radial direction of the slip ring with the sealing member in between. Unlike the brush holder, which is fixed in the axial direction with screws, the slip ring cover is used to fix the rear cover. It can be assembled with the brush holder using axial pressure.

Therefore, when the brush holder and slip ring cover are assembled, the force used to press the brush holder and slip ring cover from the radial direction is weak, and the force applied to press the brush holder and slip ring cover in the axial direction is weak. Therefore, there is a possibility that water, oil, etc. may infiltrate from this contact surface.

Therefore, in Japanese Patent Application No. 62-296894, the applicant proposed that when assembling the brush holder and slip ring cover from the radial direction of the slip ring, the assembled brush holder and slip ring cover should be assembled in a structure in which the parts are closely fitted. By arranging sealing members only on both axial end faces of the slip ring cover and the slip ring cover, we have proposed a technology that can ensure sealing around the slip ring with pressing force only in the axial direction.

As shown in FIG. 12, this prior art provides recesses 101 extending in the axial direction at both ends of a storage portion 100a formed in a brush holder 100 for storing a brush (not shown). Similarly, convex portions 103 are formed at both ends of the slip ring cover 102 and are closely fitted into the recessed portions 101, and the recessed portions 101 and the convex portions 103 are slid and fitted in close contact with each other.

Due to such 84 m, the brush holder 100 and the slip ring cover 102 can be assembled in the recessed part 101.
Since sealing performance can be obtained without using a sealing member on the contact surface between the rear cover and the convex portion 103, it is only necessary to provide the sealing member in the axial direction. Therefore, only the pressing force in the axial direction when fixing the rear cover is required It is possible to ensure sealing around the slip ring and prevent water, oil, etc. from entering.

[Problems to be Solved by the Invention] However, the brush holder 100 and the slip ring cover 102 are manufactured by resin molding;
Due to differences in molding conditions or molds, slight dimensional errors occur with respect to the desired dimensions.

For this reason, the brush holder 100 affects the sealing performance.
The axial length hl of the concave portion 101 of the brush holder 100 and the axial length 112 of the convex portion 103 of the slip ring cover 102 are not the same, and the concave portion 101 of the brush holder 100 and the convex portion 103 of the slip ring cover 102 are not the same. When fitted together,
As shown in Fig. 13, there is a step in the axial direction (for example, 0.41
1- degree) Δh3 may have occurred.

Therefore, even if the sealing members 104 were arranged on both end faces in the axial direction while maintaining the step Δ113 and were pressed from the axial direction, there was a problem in that water, dust, etc. would infiltrate through the small gap in the step. .

The present invention has been made in view of the above-mentioned circumstances, and an object thereof is to improve the sealing performance around the slip ring and to provide an alternating current generator with improved performance.

[Means for Solving the Problems] In order to achieve the above object, the present invention includes a slip ring that is provided on a rotating shaft and rotates integrally with the rotating shaft, and a brush that is in sliding contact with the slip ring. A brush holder having a storage part and having a recess or a protrusion formed in the axial direction at both ends of the storage part, and an engaging part that is closely fitted to the recess or the protrusion at both ends, a slip ring cover that covers the outer periphery of the slip ring together with the brush holder; and an axial direction of the brush holder and the slip ring cover assembled by closely fitting the recess or convex part and the engaging part. and a sealing member disposed on both end faces of the brush boulder and the slip ring cover to be assembled by receiving a pressing force in the axial direction. ,
The axial length of one of the recess or projection and the engaging portion is such that a predetermined level difference of 1 is generated in the axial direction between the recess or projection and the engaging portion. It is formed to be a predetermined amount longer than the length in the axial direction, and at least the longer part in the axial direction is made of thermoplastic resin, and the part that is longer in the axial direction is made of thermoplastic resin, and the part that is formed longer in the axial direction is The technical means is that the step is corrected and smoothed by applying heat, and then assembled at a predetermined location.

[Operation] The present invention having the above-mentioned structure is such that when the recess or projection formed on the brush holder and the engagement portion formed on the slip ring cover are fitted together, the recess or projection and the engagement portion are connected to each other. A predetermined step is formed in the axial direction between the two. At this time, the axially longer portion of the recess or protrusion and the engaging portion is made of thermoplastic resin.

As a result, the step is corrected by thermal processing, and the axial lengths of the recess or protrusion and the engaging portion are made almost the same, and the sealing surfaces at both axial ends of the brush holder and slip ring cover are smoothed. do.

After this, the brush holder and slip ring cover are assembled at a predetermined location so as to cover the outer periphery of the slip ring, and the periphery of the slip ring is sealed by applying pressure in the axial direction through the sealing member. ensure that

[Effects of the Invention] According to the present invention, when the brush holder and the slip ring cover have a structure in which the brush holder and the slip ring cover are closely fitted together so as to cover the outer circumference of the slip ring from the radial direction, the brush holder and the slip ring cover are It is possible to prevent water, oil, etc. from entering through the step portion caused by dimensional errors during molding.

As a result, the sealing performance around the slip ring can be reliably ensured using only the pressing force in the axial direction.

[Example] Next, an alternating current generator of the present invention will be described based on an example not shown in the drawings.

FIG. 1 shows a cross-sectional view of the main parts of an alternator.

AC power generation tl of this example! 11 includes a frame 2 made of aluminum alloy forming an outer shell, and rotatably supports a rotating shaft 4 via bearings 3 disposed at the center of both side walls (left and right sides in FIG. 1). The frame 2 is composed of a front frame 2a and a rear frame 2b that are substantially bowl-shaped, and a plurality of bolts 5 are arranged with the openings of the front frame 2a and the rear frame 2b facing each other.
It is assembled and fixed by.

A belt (not shown) is attached to one end (left side in Figure 1) of the rotating shaft 4 that protrudes outward from the front frame 2a.
A pulley 6 is attached to the pulley 6, which is connected to the engine via a pulley 6, and a slip ring 7 made of copper or stainless steel is attached to the other end projecting outward from the rear frame 2b.

Further, inside the frame 2, a rotor core 9 around which a rotor coil 8 is wound is fixed to the rotating shaft 4, and a slip ring 7
Together, they constitute the rotor of the alternator 1.

The rotor core 9 has six pawls 10a and 11, respectively.
It consists of a front side core 10 and a rear side core 11 made of low carbon steel having a diameter of 1.a, and are assembled so that their claw parts 10a and 11a face each other and are engaged with each other.

The front core 10 and the rear core 11 have cylindrical portions 10b and 11b formed in their respective centers by forging, and when the front core 10 and the rear core 11 are combined, the cylindrical portion 10b , 11b to the inner peripheral surfaces of the claws 10a, 11a.
will be placed.

Further, metal centrifugal cooling fans 13 and 14 are fixed coaxially with the rotating shaft 4 to both outer side surfaces of the front core 10 and the rear core 11 in order to cool the rotor core 9.

The rotor coil 8 is concentrically wound around the outer periphery of the cylindrical portions 10b and 11b via an insulating bobbin 12, and the winding start and winding ends are electrically connected to the slip ring 7, respectively.゛A stator core 15a and a stator coil 15b wound around the stator core 15a are provided on the outer circumference of the rotor core 9.
A stator 15 composed of
It is fixed to the inner wall of the frame 2 so as to face the claw parts 10a and 11a.

On the outside of the aforementioned rear frame 2b, a brush 16 made of electrolytic graphite or metal graphite is provided so as to be in sliding contact with the outer peripheral surface of the slip ring 7, and a pigtail 17 molded simultaneously with this brush 16 and the brush 16 is held. a brush holder 18; a slip ring cover 19 that protects the outer periphery of the slip ring 1 together with the brush holder 18;
A rectifier 20 for rectifying the output current of the stator coil 15b is provided, and is covered by a rear cover 21. Note that the rear cover 21 is fixed to the rear frame 2b with a plurality of bolts 22.

The brush 16 is pressed against the outer peripheral surface of the slip ring 7 by a brush spring 23 housed in the brush holder 18, and comes into sliding contact with the outer peripheral surface of the slip ring 1 as the slip ring 7 rotates.

The brush holder 18 and the slip ring cover 19 are assembled together so as to cover the outer periphery of the slip ring 1, and when tightening or fixing the rear cover 21, the brush holder 18 and the slip ring cover 19 are attached in the axial direction. Rear frame 2br! via rubber seal members 24 and 25 provided on both end surfaces of the rear frame 2br! ! Pressed by I4.

Next, brush holder 18 and slip ring cover 1
The structure and assembly of No. 9 will be explained.

b) Clarification regarding the structure of the brush holder 18.

Note that FIG. 2 is a perspective view showing how the brush holder 18 and slip ring cover 19 are assembled, FIGS. 3 and 4 are perspective views of the brush holder 18, and FIG.
The perspective view, FIG. 6, is a cross-sectional view of the brush holder 18 in the radial direction.

The brush holder 18 made of a thermosetting resin holds the brush 16
The sheath part 28 has a first storage part 26 for storing the pigtail 17 and a second storage part 21 for storing the pigtail 17. A thick portion 29 is formed in a concave curved shape along the outer peripheral surface of the ring 7.

As shown in FIG. 5, two first storage portions 26 and two second storage portions 27 are provided each, and are formed so as to be able to hold two brushes 16 side by side in the axial direction.

Further, the brush holder 18 is integrally molded with a positive terminal 30 and a negative terminal 31 made of metal plates protruding from both side surfaces 28a in the radial direction of the sheath portion 28. Note that the brush holder 18 is attached to the positive side terminal 30 and the negative side terminal 31 at F! Screw holes 30a and 31a are provided for screwing to the flow 2s20 and an IC regulator (not shown).

As shown in FIG. 3, recesses 33 having a rectangular cross section are formed at both ends in the radial direction of the concavely curved surface 32 of the thick portion 29 over the entire length in the axial direction. Further, between the recessed portion 33 and the first storage portion 26, four shallow extinguishing portions 34 extending in the axial direction are formed.

On both end faces in the axial direction of the thick portion 29, there are two U-shaped small protrusions 35a, 3 surrounding the bottom side of the recess 33.
6a, and these two U-shaped small protrusions 35a, 36a.
small arcuate protrusions 35b, 36b formed to connect
A first small protrusion 35. with a height of about 0.5a+m.
36 are formed.

Therefore, the axial length of the recess 33 is the sum of the axial length of the thick part 29 and the height of the first small projections 35 and 36 formed on both end surfaces of the thick part 29. .

Further, on the other end surface 28h in the axial direction of the sheath portion 28, a flat portion 37 having an area approximately 2/3 of the other end surface 28b is formed slightly higher than the other end surface 28b.

Furthermore, two convex portions 38 are formed on both end surfaces of the two thick portions in the radial direction.

As shown in FIG. 1, the brushes 16 are housed together with brush springs 23 in the first housing part 26 of the brush holder 18, and one end of the pigtail 11 housed in the second housing part 21 is soldered. This prevents the nuki from falling. Further, the other end of the pigtail 17 is connected to the sheath part 2.
At the bottom of the terminal 8, it is soldered and electrically connected to the positive end (30) or the negative terminal 31.

Ex) Explanation regarding the structure of the slip ring cover 19.

7 is a perspective view of the slip ring cover 19, FIG. 8 is a plan view of the slip ring cover 19, and FIG. 9 is a four side view when the brush holder 18 and slip ring cover 19 are assembled.

The slip ring cover 19 is intended to cover and protect the slip ring 1 assembled on the rotating shaft 4, and has a shape in which about 1/4 of the circumference of the cylinder body is removed, and its radial cross-sectional shape is the same as the circumference. Approximately 374. Therefore, as shown in FIGS. 7 and 8, the slip ring cover 19 is constituted by a substantially cylindrical peripheral wall 39 made of thermoplastic resin (for example, made of nylon) and having an approximately 3/4 circle in the circumferential direction. .

Brush holders 1 are provided at both ends of the peripheral wall 39 in the circumferential direction.
A relatively thin V-shaped convex portion (engaging portion of the present invention) 40 extending in the axial direction is formed to be fitted into the recess 33 of No.8. Further, a hook-shaped protrusion 41 that engages with the protrusion 38 of the brush holder 18 is formed on the outside of the V-shaped protrusion 40.
l (Fig. 7, side) includes a locking portion 4 that locks with the convex portion 38 and restricts movement of the slip ring cover 19 in the axial direction.
1a is formed.

Further, inside the V-shaped convex portion 40, a brush holder 18 is provided.
A flat portion 42 is formed along the inner circumferential side of the recess 33 , and a plurality of rod-shaped protrusions 43 extending in the axial direction are formed on the inner circumferential surface of the peripheral wall 39 .

And, like the first small projections 35.3 of the brush holder 18, the peripheral wall 39 has a height of approximately 0.5 on both end faces in the axial direction.
A second small projection 44.45 having a width of approximately 0.5 m is formed in the circumferential direction and is connected to the V-shaped projection 40.

Therefore, the axial length of the V-shaped protrusion 40 is the sum of the axial length of the peripheral wall 39 and the height of the second small projections 44.45 formed on both end surfaces of the peripheral wall 39. .

Note that the width Ll of the V-shaped protrusion 40 (see FIG. 8) is slightly larger than the width L2 of the recess 33 of the brush boulder 18 (see FIG. 6), and the tip of the hook-shaped protrusion 41 and Distance 31 between the tip of the V-shaped convex portion 40 (see Fig. 8)
is the distance between the bottom of the concave portion 33 and the tip of the convex portion 38 of the brush holder 18! It is formed slightly larger than S2 (see FIG. 6).

Furthermore, as shown in FIG. 111 is the axial length (
The length of the recess 33 in the axial direction is slightly longer than 112 (for example, about 0 to 0.411).

Therefore, when the V-shaped protrusion 40 of the slip ring cover 19 is fitted into the recess 33 of the brush holder 18, a predetermined amount of step Δold is generated in the axial direction.

c) Explanation regarding the assembly of the brush holder 18 and slip ring cover 19.

First, both end surfaces of the slip ring cover 19 in the axial direction are fixed with a jig (not shown), and while sliding the recess 33 of the brush boulder 18 held by the jig, the v-shaped protrusion of the slip ring cover 19 is 40. At this time, the convex portion 38 of the brush holder 18
ζ along the hook-shaped protrusion 41 of the slip ring cover 19.

In this way, the recess 33 of the brush holder 18 and the V-shaped protrusion 40 of the slip ring cover 19 are fitted together, and the end surfaces of the first small protrusion 35 and the second small protrusion 44 are made to be the same and flat, for example. In this case, as shown in FIG.
3, a predetermined level difference Δ113 is formed between the end face of the first small protrusion 36 and the end face of the second small protrusion 45, and the V-shaped Convex portion 4
0 stands out. Therefore, the protruding V-shaped convex portion 40 of the slip ring cover 19 having a low melting point is subjected to thermal caulking, which is the thermal processing of the present invention, to correct the step Δ113 and to form the concave portion 33.
and the V-shaped convex portion 40 are smoothly connected to each other.

As a result, both end surfaces in the axial direction when the brush holder 18 and slip ring cover 19 are assembled are substantially flattened.

Note that when sliding the recess 33 and fitting it into the V-shaped protrusion 40, as described above, the width of the ■-shaped protrusion 40 [1] should be slightly larger than the width [2] of the recess 33. From the V-shaped protrusion 4 of the slip ring cover 19
0 into which the recess 33 of the brush holder 18 is press-fitted.

Further, the distance S1 between the tip of the hook-shaped protrusion 41 and the tip of the V-shaped protrusion 40 is slightly larger than the distance S2 between the bottom of the recess 33 of the brush holder 18 and the tip of the protrusion 38. Therefore, when fitting the recess 33 into the V-shaped projection 40, the tip of the ■-shaped projection 4'o will fit into the recess 33.
It will be inserted into the corner of the bottom with a predetermined tightening margin.

As a result, the recess 33 of the brush holder 18 is tightly fitted into the V-shaped protrusion 40 of the slip ring cover 19, and the brush holder 18 and slip ring cover 19 can be assembled easily without using a sealing member. It is possible to ensure the sealing performance of the part.

In addition, the hook-shaped protrusion 41 of the slip ring cover 19
is fitted with the convex portion 38 of the brush holder 18, so that the slip ring cover 19 is fitted to the brush holder 18.
can maintain the correct posture.

After fitting the brush holder 18 and the slip ring cover 19 together in this manner, as shown in FIG. The rear cover 21 is tightened and fixed by intervening.

As a result, the sealing members 24 and 25 are pressed and elastically deformed, sealing both end surfaces of the brush holder 18 and the slip ring cover 19 in the axial direction.

Note that FIG. 10 shows a perspective view of the seal member 24 disposed on the rear frame 2b side, and FIG. 11 shows the rear cover 21.
A perspective view of a sealing member 25 disposed on the side is shown.

The sealing member 24 on the side of the rear frame 2 [1] is formed of foamed silicone rubber, and as shown in FIG. It consists of a flat portion 37 and a rectangular portion 24b that abuts.

The sealing member 25 on the rear cover 21 side is made of rubber, and as shown in FIG. 19 and the first small protrusion 36 of the brush holder 18 contact, a passage 25C that connects the inside and outside of the cylindrical part 25a as shown by the broken line in the figure; 6. As described above, the brush holder 18 and the slip ring cover 19 are fitted closely together to take advantage of the dimensional error that occurs during resin molding. Then, the axial step difference Δ11' between the brush holder 18 and the slip ring cover 19 is
By heat caulking 3, it is possible to ensure sealing around the slip ring 7 only by pressing force in the axial direction, and it is possible to prevent water, oil, etc. from entering.

Further, a thin V-shaped convex portion 40 is formed as an engaging portion of the present invention that is fitted into the concave portion 33 of the brush holder 18,
Since the V-shaped protrusion 40 is fitted into the recess 33 of the brush holder 18 with a predetermined tightness, the hook-shaped protrusion 41 of the slip ring cover 19 and the side surface of the thick part 29 of the brush holder 18 are connected to each other. Even if oil or the like intrudes from the gap, the thin V-shaped convex portion 40 can reliably seal.

Furthermore, by forming four shallow grooves 34 around the first storage part 26 in which the brush 16 is stored,
Even if a small amount of oil penetrates into the interior through the thin V-shaped convex portion 40 described above, the oil will not accumulate in the shallow groove portion 34 and will not adhere to the brush 16.

(Modification) In the embodiment described above, the brush holder 18 is provided with a recess and the slip ring cover 19 is provided with a protrusion, but the brush holder 18 may be provided with a protrusion and the slip ring cover 19 may be provided with a recess.

In addition, the slip ring cover 19 was formed of thermoplastic resin in order to thermally caulk the step Δ113, but the axial length of the recess 33 of the brush holder 18 + 12 Axial length 1
The brush holder 18 may be formed longer than 11, and the brush holder 18 may be made of thermoplastic resin and heat caulked.

As the engaging portion of the present invention, a thin V-shaped protrusion 40 is formed on the slip ring cover 19.
There may be one, or three or more.

Recess 33 of brush holder 18 and slip ring cover 1
9, the axial length of the V-shaped protrusion 40 was formed to be slightly longer than the axial length of the recess 33, but conversely, the axial length of the recess 33 The step difference Δ113 may be corrected by forming the V-shaped convex portion 40 so that its length is slightly longer than the length in the axial direction and heat caulking the protruding concave portion 33.

[Brief explanation of the drawing]

Figure 1 is a sectional view of the main parts of the alternator, Figure 2 is a perspective view showing how the brush holder and slip ring cover are assembled, Figures 3 and 4 are perspective views of the brush holder, and Figure 5 is a perspective view of the brush holder.
The figure is a view from A in Fig. 3, Fig. 6 is a cross-sectional view of the brush holder in the radial direction, Fig. 7 is a perspective view of the slip ring cover, Fig. 8 is a plan view of the slip ring cover, and Fig. 9 is a brush holder. A side view when the holder and slip ring cover are assembled, FIGS. 10 and 11 are perspective views of the sealing member, and FIGS. 12 and 13 are the brush holder and slip ring showing an example of the applicant's earlier application. A perspective view and a side view showing the state of assembly with the cover. In the diagram 1... AC generator 4... Rotating shaft 7...
Slip tour ring 16...Brush 18...Brush holder 19...Slip ring cover 24.25
Seal member 33... Concave portion 40... V-shaped convex portion (engaging portion) Δ113... Step 'difference

Claims (1)

[Claims] 1) A slip ring that is provided on a rotating shaft and rotates together with the rotating shaft, and a storage part for storing a brush that slides in contact with the slip ring, and both ends of the storage part. a brush holder having a recess or a protrusion formed in the axial direction; and an engaging part that is closely fitted to the recess or the protrusion at both ends, and covers the outer circumference of the slip ring together with the brush holder. The slip ring cover is disposed on both end surfaces in the axial direction of the brush holder and the slip ring cover, which are assembled by closely fitting the concave portion or the convex portion and the engaging portion, and prevents axial pressure. and a sealing member that is assembled under pressure, and the brush holder and the slip ring cover are configured so that when the recess or projection and the engagement portion are fitted together, the recess or projection and the engagement portion are connected to each other. The length in the axial direction of either the recess or the convex part and the engaging part is formed to be longer by a predetermined amount than the length in the axial direction of the other so that a step of a predetermined amount is generated in the axial direction between the concave portion or the convex portion and the engaging portion. ,and,
At least the part that is long in the axial direction is made of thermoplastic resin, and after smoothing and correcting the step that occurred when the recess or convex part and the engaging part are fitted together, the part is formed into a predetermined shape. An alternating current generator characterized by being assembled at a location.