JPH0528921Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a rotating electrical machine equipped with a composite body of a brush holder made of resin and a bracket made of metal, and in particular, the contact surface between the bracket and the brush holder is For example, a composite of a bracket and a brush holder (hereinafter referred to as
It is called a bracket unit. ), which is an effective technique for use in a bracket in which a brush holder is integrally molded with resin.

[Conventional technology]

As a bracket unit used in a starter motor, one in which a brush holder is integrally molded using resin on a bracket formed in the shape of a thin plate has been proposed (for example,
(Refer to Publication No. 124482).

[Problem that the invention attempts to solve]

In such a bracket unit, if an iron-based material is used for the bracket and a nylon resin is used for the brush holder, when an environmental test such as a thermal shock test is conducted, the heat between the bracket and the brush holder will be reduced. Due to the difference in expansion coefficients, a relative deviation occurs between the contact surfaces of the two,
As a result, the inventor of the present invention has revealed that the airtightness and liquidtightness of the starter motor housing to which this bracket unit is assembled deteriorates.

An object of the present invention is to provide a rotating electrical machine that can prevent a decrease in sealing performance due to relative misalignment between the contact surfaces of a bracket and a brush holder.

[Means for solving problems]

In the rotating electric machine according to the present invention, in the bracket unit, a sealing member made of flexible resin or rubber is disposed on the contact surface of the bracket with the brush holder, and the brush holder is resin-molded so that the sealing member is implanted. It is characterized by

[Effect]

According to the above-mentioned means, since the sealing member is disposed on the bracket and is implanted in the brush holder, the sealing state is achieved by blocking the gap therebetween.

In addition, since the sealing member made of flexible resin or rubber has rubber elasticity, it becomes compressed when the brush holder contracts after resin molding, and it firmly adheres at the interface between the brush holder and the bracket. Become. When a relative displacement (slippage) occurs between the contact surfaces of the bracket and the brush holder due to the difference in thermal expansion coefficients, the rubber elastic deforms to follow the displacement while maintaining close contact with both. By doing so,
The sealed state can be maintained.

〔Example〕

Fig. 1 is a partially cutaway enlarged side view showing a bracket unit used in a starter motor which is an embodiment of the present invention, Fig. 2 is a longitudinal cross-sectional view showing the starter motor, and Fig. 3 is the same as Fig. 2. 4 is an enlarged partial sectional view showing the terminal part, FIG. 5 is an exploded perspective view of the starter motor, FIG. 6 is a longitudinal sectional view showing the process in progress, and FIGS. FIG. 8 is an enlarged partial sectional view for explaining the action, and FIG. 9 is a schematic diagram for explaining the experimental method.

In this embodiment, the rotating electric machine according to the present invention is configured to be used as a starter motor, and includes a stator 1, a rotor 2, and a bracket unit 3 as a composite of metal and resin.

The stator 1 includes a yoke 4 which is integrally formed using a magnetic material by suitable means such as drawing press processing.
The yoke 4 has one end surface (hereinafter referred to as the front side) open and the other end surface (hereinafter referred to as the rear side).
It is formed into a substantially cylindrical shape with a closed area. A flange portion 6 is provided on the outer edge of the opening 5 of the yoke 4 to protrude in the radial direction, and the flange portion 6 has a pair of bolt insertion holes 7 and a pair of screw insertion holes 8 arranged above and below, respectively. It is perforated. A pair of anti-rotation protrusions 9 are disposed on the left and right and protrude from the inner edge of the opening 5 of the yoke 4. A bearing member accommodating portion 10 is formed in a cylindrical shape on the closed wall of the back surface of the yoke 4, and a bearing member 11 is fitted inside this accommodating portion 10. yoke 4
A plurality of magnets 12 are fixed to the inner circumferential surface of the magnet 12 at equal intervals in the circumferential direction so as to form a magnetic field.

The rotor 2 includes a shaft 13 that is longer than the length of the yoke 4, and a commutator 14 and an armature 15 are arranged and fixed on the outer periphery of the intermediate portion of the shaft 13 in front and behind. Shaft 13
A pinion 16 is carved in the front end of the starter, and the pinion 16 is adapted to mesh with a driven gear 17 of the starter in the assembled state. Journal parts 18 and 19 are formed at the rear position and rear end of the pinion 16 on the outer periphery of the shaft 13, respectively, and the shaft 13 has both journal parts 18 and 19 connected to a bearing member 58 and the yoke 4, which will be described later. By being supported by the disposed bearing members 11, the shafts are rotatably mounted inside the yoke 4.

The bracket unit 3 as a composite of metal and resin according to the present invention is equipped with a brush holder 20 as a resin structure integrally molded into a substantially disk shape from nylon resin.
is integrally formed with the bracket 21 as a metal member. Further, a terminal member 33 is implanted at a predetermined position of the brush holder 20 so as to pass through the bracket 21 in an insulating state, as shown in FIG.

Here, the structure of the bracket unit will be clarified by explaining the method of manufacturing the bracket unit.

The bracket 21 is made of a conductive plate material such as an iron plate, and is formed by punching and pressing into a fifth plate so as to correspond to the outer shape of the flange portion 6 of the yoke 4.
It is formed into a flat plate shape as shown in the figure. A pair of bolt insertion holes 22 and screw holes 23 are provided at the upper and lower portions of the bracket 21, respectively. A window hole 24 is formed approximately in the center of the bracket 21 so that the inner diameter is slightly larger than the outer diameter of the commutator 14, and a plurality of small holes 25 are arranged around the window hole 24 in the circumferential direction. It has been established. A bearing member accommodating portion 57 is integrally connected to the window hole 24 in a circular bowl shape. Further, an insertion hole 34 larger than the width and thickness of the terminal member 33 is provided at a position approximately 45 degrees from the upper left corner of the bracket 21.

When the brush holder 20 is molded onto the bracket 21, as shown in FIG.
is set so as to be sandwiched between the molds 70. Although detailed description is omitted, the mold 70 includes an upper mold 71 and a lower mold 72, and a cavity 73 with a gate 74 opened on the mating surfaces thereof.
However, the brush holder 2 has a configuration as described below.
It is embedded in a shape that can form 0. The bracket 21 attaches the brush holder 2 to this cavity 73.
The part to be molded is inserted and set so as to be sandwiched between the upper mold 71 and the lower mold 72.

At the same time, the terminal member 33 is inserted into the insertion hole 34 of the bracket 21 without contacting it, and passes through the cavity 73 to insert the upper mold 71 and the lower mold 7.
Positioned and held at 2.

Here, before the bracket 21 is set in the mold 70, an annular groove 76 is formed at a position inside the group of small holes 25 on the end surface of the bracket 21, which is the part where the brush holder 20 is to be molded and faces the yoke. A sealing member 75 formed in a circular ring shape using a flexible resin is fitted into this annular groove 76 so as to be positioned. has been done.

Examples of the flexible resin used to form the sealing member include methyl methacrylate resin, polyacrylic acid ester, vinyl chloride resin, and vinyl chloride/vinylidene chloride copolymer resin. In short,
Any material may be used as long as it exhibits the effects described below after implantation.

As mentioned above, once the bracket 21 and the terminal member 33 are appropriately set in the mold 70,
The cavity 73 is filled with nylon resin as a molding material through the gate 74 in a heated and molten state at about 280°C, and the brush holder 20 as a resin structure made of nylon resin is integrally molded in the bracket 21. At the same time, a terminal member 33 is implanted into the brush holder 20.

That is, the bracket 21 is the brush holder 20
When the brush holder 2 is molded, the part from the inner edge of the window hole 24 to the outside of the small hole 25 is molded so as to be placed substantially perpendicular to the axis of the brush holder 2.
It is integrated into the brush holder 20 while being sandwiched between the front wall part 26 and the rear wall part 27 of 0. In this state, a portion of the nylon resin forming the brush holder 20 is inserted into each small hole 2 of the bracket 21.
5 are filled in to form solid cylindrical portions 28, and these cylindrical portions 28 integrate the bracket 21 and the brush holder 20 in a state where they are completely prevented from rotating. Moreover, when the brush holder 20 is resin-molded, the terminal member 3
3 is fixedly held by a substantially rectangular parallelepiped-shaped holding portion 35 whose insertion hole 34 is filled with resin.

At the same time, an annular groove 76 is formed on the rear surface of the bracket 21 inside the rear wall portion 27 of the brush holder 20.
The sealing member 75 positioned according to this will be integrally implanted. In this case, the nylon resin of the brush holder 20 spreads to every corner of the uneven parts of the sealing member and comes into contact with it evenly, and the sealing member 75 is compressed in all directions due to contraction as the nylon resin hardens. Therefore, at the interface between the brush holder 20 and the annular groove 76 of the bracket 21, the brush holder 20 and the bracket 21 come into close contact with each other under the elastic force of the rubber.

A hole is formed at the lower left corner of the front wall 26 of the brush holder 20 at approximately 45 degrees so that the skin of the bracket 21 is exposed. A rear hole 31 is similarly opened at a position corresponding to the front hole in the rear wall 27 of the brush holder 20.
The exposed surface of the bracket 21 at the bottom of the rear hole 31 forms a pigtail connection 32 for connecting a pigtail. Terminal member 3
A portion protruding forward from the holding portion 35 of No. 3 forms a second lead wire connection portion 36, and a portion protruding rearward forms a second pigtail connection portion 37, respectively.

The outer diameter of the rear wall portion 27 of the brush holder 20 is set to be approximately equal to the inner diameter of the opening 5 of the yoke 4, and the axes thereof coincide, so that the outer circumference of the rear wall portion 27 and the yoke The inner periphery of the opening 5 substantially constitutes a male seal-coupling part 38 and a female seal-coupling part 39.
At the left and right positions on the outer edge of the back surface of the rear wall portion 27,
A pair of rising walls 40 are each erected in a direction substantially parallel to the axis, and a detent recess 41 is recessed in the outward facing surface of both rising walls 40 in the shape of connecting a circle to the apex of an inverted triangle. has been done. When the first male and female seal coupling parts 38 and 39 are in a coupled state, the anti-rotation recesses 9 that protrude from the inner edge of the opening 5 of the yoke 4 fit into the anti-rotation recesses 41, respectively. ing.

A pair of brush accommodating chambers 42 are disposed at upper and lower positions on the back surface of the rear wall portion 27 so as to face each other, and the accommodating chambers 42 are provided with a pair of guide walls protruding parallel to each other and facing each other. 43, it is formed into a hollow, substantially rectangular parallelepiped shape with both end faces in the radial direction and three sides of the back surface open. A pin 44 for forming a caulking portion 44A is provided on the back surface of each guide wall 43, and a pin 44 for forming a caulking portion 44A is provided at the inner side of one of the rising walls 40 for positioning a fall prevention plate to be described later. A pin 45 is provided protrudingly. The opening on the back side of the brush storage chamber 42 is closed by a drop-off prevention plate 46 fixed by each pin while in contact with the back surface of each guide wall 43 .

A pair of brushes 51A and 51B are provided in both storage chambers 42.
The pigtails 52A, 52B are arranged facing inward and slidably inserted in the radial direction, and the pigtails 52A, 52B planted on both the brushes 51A, 51B are inserted into the insertion holes provided at the top and bottom of the fall prevention plate 46. 49 in a slidable manner. The end of the pigtail 52A of the brush 51A disposed on the upper side is connected to the pigtail connection portion 37 of the terminal member 33, and the end of the pigtail 52A of the brush 51B disposed on the lower side is connected to the pigtail connection portion 37 of the terminal member 33.
The terminal is connected to the pigtail connection 32 of the bracket 21.
and are electrically connected to the terminal member 33 and the bracket 21.

A pair of springs 53 are inserted from the outward opening of the accommodation chamber 42 and housed outside the brushes 51A, 51B of the accommodation chamber 42, respectively, and the springs 53 are fixed to the outward opening of the accommodation chamber 42. By applying a reaction force to the cap 54 and urging the brush inward, the brush is pressed against the commutator 14 of the rotor 2.

A substantially cylindrical bearing member accommodating portion 57 is formed in a position corresponding to the window hole 24 of the bracket 21 so as to protrude forward, and a bearing member 58 made of a ball bearing or the like is accurately inserted into this accommodating portion 57. It is fitted and aligned with the axis. The axial center of this accommodating part 57 is set to coincide with the axial center of the male seal joint part 38 formed by the outer periphery of the rear wall part 27 of the brush holder 20. The axis of the bearing member 58 that is housed with its axes aligned is the male seal coupling part 38.
This means that it is aligned with the axis of the

When the bracket unit 3 configured as described above is assembled to the stator 1 and the rotor 2, the brush holder 20 is inserted into the opening 5 of the yoke 4 with male and female markings on the outer and inner circumferential surfaces of both brushes. The seals are coupled by the coupling portions 38 and 39, and their axes are aligned. In this state, the axis of the bearing member 58 is aligned with the male seal coupling part 38 of the brush holder 20, so that the axis of the bearing member 58 is also aligned with the axis of the yoke 4. Therefore, the shaft 13 of the rotor 2 has the journal parts 18 and 19 supported by the bearing member 58 and the bearing member 11 at the rear end of the yoke 4.
is precisely aligned with the stator 1 and rotatably supported.

When the opening 5 of the yoke 4 and the brush holder 20 are coupled together, the anti-rotation protrusion 9 and the recess 41 are aligned and fitted to each other. When both 9 and 41 are fitted, the bolt insertion hole 7 and screw insertion hole 8 in the flange portion 6 of the yoke 4 are aligned with the bolt insertion hole 22 and screw insertion screw hole 23 of the bracket 21, respectively. It turns out. Screw 5
9 is inserted into the insertion hole 8 of the flange portion 6 of the yoke 4 and screwed into the screw hole 23, the bracket 21 and the yoke 4 are connected, so that the stator 1 and the rotor 2
The bracket units 3 are combined and integrated at once with their axes and positions aligned. Although detailed explanation is omitted, in this three-part state, the boss portion 61 of the engine case 60
The bearing member accommodating portion 57 is fitted into the bearing member accommodating portion 57 . If the axes of the boss portion 61 of the engine case 60 and the bearing member accommodating portion 57 are set to coincide with each other, the shaft 13 supported by the bearing member 58 of the bearing member accommodating portion 57 will be aligned with the boss portion 61. The axis will be aligned. Therefore, the pinion 16 carved in the shaft 13 meshes with the driven gear 17 accurately.

Next, the effect will be explained.

As mentioned above, since the starter motor is connected to the engine case, it is expected that it will be exposed to temperature environments ranging from extremely cold atmospheric temperatures to engine overheating temperatures. Therefore, starter motors are subjected to environmental tests including several dozen thermal shock tests in the range of approximately -20°C to 150°C.

By the way, when a bracket unit without a sealing member embedded between the contact surface of the bracket and the brush holder is used in a starter motor, when a thermal shock test is carried out, it is found that due to the difference in thermal expansion coefficient between metal and resin. As shown in FIG. 7, a relative displacement 77 occurs between the contact surfaces of the bracket 21' and the brush holder 20', so that the airtightness of the motor housing deteriorates in the subsequent airtightness test. was clarified by the present inventor. This is because a minute gap 77 is generated due to the relative misalignment between the contact surfaces of the bracket 21' and the brush holder 20', and this gap creates an unexpected ventilation path that cannot be controlled, as shown by the arrow in FIG. This is thought to be due to the fact that it is formed as shown in the figure. If such a relative misalignment occurs between the contact surfaces of the bracket and the brush holder, rainwater, condensed water, etc. from the outside will enter the inside of the motor housing, resulting in a loss of motor performance.

However, in this embodiment, the bracket 21
Since a sealing member 75 made of flexible resin is implanted between the contact surfaces of the motor housing and the brush holder 20, the airtightness of the motor housing is maintained as expected even after a thermal shock test is conducted. be done. Therefore, rainwater, condensed water, etc. from the outside are prevented from entering the inside of the housing between the contact surfaces of the bracket 20 and the brush holder 21.

That is, since the seal member 75 is implanted into the brush holder 20 while being positioned in the annular groove 76 of the bracket 21, the seal member 75 is positioned in the annular groove 76 of the bracket 21.
6 is integrally connected in shape, and the elastic force of the sealing member 75 generated by compressive deformation due to contraction of the nylon resin causes pressure contact on the contact surface of the brush holder 20. It has become a state. In addition, the annular groove 7
6 also serves to lengthen the leak path. Therefore, even if a relative deviation occurs between the contact surfaces of the bracket 21 and the brush holder 20 due to the difference in thermal expansion coefficient between the metal and the resin in the thermal shock test, as shown in FIG. In addition, the sealing member 75 is attached to the bracket 21 and the brush holder 2.
It will adhere or come into close contact with both.

In addition, since the sealing member 75 made of a flexible resin has excellent flexibility, it allows displacement between the bracket 21 and the brush holder 20 due to the difference in thermal expansion coefficients by flexibly deforming the bracket 21 and the brush holder 20. The integrity of the member 75 itself will be maintained. Therefore, even if a relative displacement occurs between the contact surfaces of the bracket 21 and the brush holder 20, the sealing member 75 ensures that a gap or a ventilation path is formed between the two. As a result, the motor housing can maintain the desired tightness even after the thermal shock test.

This airtightness experiment is conducted as follows.

First, an experimental sample consisting of a bracket unit assembled to a yoke was heated from -20°C to 150°C for about 20°C.
Cooling and heating are repeated more than 10 times at intervals of time.

As shown in Figure 9, this thermal
In the experimental sample 78 subjected to the shock test, a compressor 79 is fluidly coupled via a hose 80 to an airtight chamber formed inside by the bracket unit and yoke, and a pressure gauge 81 is connected to the airtight chamber. Attached so that internal pressure can be measured.

In this set state, the experimental sample 78 is immersed in water in the water tank 82, and air is forced into the airtight chamber by the compressor 79. Then, the bracket 21 and the brush holder 20 in the bracket unit
The pressure gauge 81 measures the internal pressure of the airtight chamber when bubbles 83 are generated between the contact surfaces.
Incidentally, if the experimental value is 0.3 kg/cm ² or more, the water intrusion phenomenon from the contact surface between the bracket and the brush holder can be sufficiently withstood in practical use.

It should be noted that the present invention is not limited to the above-mentioned embodiments, and may be modified without departing from the gist thereof.
It goes without saying that various changes are possible.

For example, the sealing member is not limited to being formed using a flexible resin, but may also be formed using rubber. Examples of the rubber include rubber-like elastic polymer compounds such as chlorinated rubber, cyclized rubber, butadiene-based synthetic rubber, neoprene, butyl rubber, and the like.

Further, the means for positioning the sealing member in the bracket is not limited to the structure in which the sealing member is fitted into the annular groove;
The structures shown in FIGS. and 12, respectively, may also be used.

In the structure shown in FIG. 10, a sealing member 75 is adhesively fixed onto the bracket 21 by an adhesive layer 76A.

In the structure shown in FIG. 11, a positioning ring 76B is fixedly protruded on the bracket 21, and a sealing member 75 is fitted onto this ring 76B.

In the structure shown in FIG. 12, after the seal member 75 is fitted into the annular groove 76 recessed in the bracket 21, a sealing process is performed. securely fixed.

The bracket is not limited to being constructed using iron-based materials, but may be constructed using other metal materials, and the brush holder is not limited to being constructed using nylon resin, but may be constructed using other resins. You can.

Although the above embodiment has been described with reference to the application to a starter motor, the present invention is not limited thereto, and can be applied to all rotating electric machines such as other motors and generators. In particular, excellent effects can be obtained when applied to products that require liquid-tightness or airtightness.

[Effect of idea]

As explained above, according to the present invention, a sealing member made of rubber is burned onto the contact surface of the bracket with the brush holder, and this sealing member is implanted and molded inside the brush holder.
Even if a relative displacement occurs between the contact surfaces of the bracket and the brush holder, a sealed state can be maintained.

[Brief explanation of drawings]

Fig. 1 is a partially cutaway enlarged side view showing a bracket unit which is an embodiment of the present invention, Fig. 2 is a longitudinal cross-sectional view showing a starter motor in which it is used, and Fig. 3 is the same as that shown in Fig. 2. 4 is an enlarged partial sectional view showing the terminal section, and 5 is a sectional view taken along the line.
The figure is an exploded perspective view of the starter motor, Figure 6 is a vertical sectional view showing the process in progress, Figures 7 and 8 are enlarged partial sectional views to explain the operation, and Figure 9 explains the experimental method. FIG. 1st
FIG. 0, FIG. 11, and FIG. 12 are longitudinal sectional views showing modifications of the present invention, respectively. DESCRIPTION OF SYMBOLS 1... Stator, 2... Rotor, 3... Bracket unit, 4... Yoke, 5... Opening, 6...
...Flange portion, 7... Bolt insertion hole, 8... Screw insertion hole, 9... Anti-rotation convex portion, 10... Bearing member housing portion, 11... Bearing member, 12... Magnet, 13... Shaft, 14... Commutator, 15... Armature, 16... Pinion,
17... Driven gear, 18, 19... Journal part, 20... Brush holder, 21... Bracket, 22... Bolt insertion hole, 23... Screw hole, 24... Window hole, 25... Small hole, 26...
Front wall part, 27... Wall part, 28... Cylindrical part, 31...
...Back hole part, 32...Pigtail connection part, 33...
...Terminal member, 34...Terminal member insertion hole, 35...Terminal member holding part, 36...Lead wire connection part, 37...Pigtail connection part, 38
... Male seal joint part, 39 ... Female seal joint part, 40
...Rising wall, 41... Rotating recess, 42
...Brush storage chamber, 43...Guide wall, 44...
Pin, 44A... Locking part, 45... Positioning pin, 46... Fall prevention plate, 47... Covering part, 48
...Connection part, 49...Pigtail insertion hole, 50...
...Small hole, 51A, 51B...Brush, 52A, 5
2B...Pigtail, 53...Spring, 54
...Cap, 55, 56...Engagement convex portion, 57...
...Bearing member housing portion, 58...Bearing member, 59...
Screw, 60...Engine case, 61...Boss part, 62...Screw hole for screwing in bolt, 63...Bolt, 70...Mold, 71...Upper die, 72...Lower die, 73... Cavity, 74...Gate, 7
5... Seal member, 76... Annular groove, 76A...
Adhesive layer, 76B...Positioning ring, 76C
... Kotsuking processing part, 77 ... Gap, 78 ...
Experimental sample, 79...Compressor, 80...Hose, 81...Pressure gauge, 82...Water tank, 83...Bubble, 84...Vent passage.

Claims (1)

[Claims for Utility Model Registration] (1) In a rotating electric machine in which a brush holder is integrally molded using resin on a bracket formed in the shape of a thin plate, and this bracket is abutted on an opening of a yoke, A rotating electric machine characterized in that a sealing member made of flexible resin or rubber is disposed on a contact surface of the bracket with the brush holder, and the sealing member is embedded in the brush holder. (2) The sealing member 75 is formed in an annular shape so as to surround the window hole 24 of the bracket 21 by being disposed radially inside the through holes 25 and 34 of the bracket 21 that are filled with a portion of the resin of the brush holder. A rotating electric machine according to claim 1, which is a utility model.