JP3086647B2 - Small motor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a small motor such as a stepping motor. More specifically, the present invention relates to an improvement in a small motor having a stator structure in which a plurality of stator sets each including an outer stator and an inner stator are stacked.

[0002]

2. Description of the Related Art Conventionally, there has been known a small motor having a stator structure in which a plurality of stator sets each including an outer stator and an inner stator are vertically stacked. For example, FIG.
In the stepping motor as shown in FIG. 3, the first outer stator 31 having the pole teeth 31b and the outer periphery of the motor case and the first inner stator 3 having the pole teeth 32b are formed.
2, a first stator set 34 sandwiching a winding coil 33 wound around a coil bobbin, pole teeth 35b, and a second outer stator 35 and pole teeth 36b constituting the outer periphery of the motor case. A second stator set 38 sandwiching a winding coil 37 wound around a coil bobbin with the second inner stator 36;
36 are the winding coil 33 and the winding coil 37
To form a stator structure. The pole teeth 3 are located at the center of the stator structure.
A rotor 39 is arranged to face 1b, 32b, 35b, 36b.

[0003] Specifically, this stator structure is formed as follows. That is, first, as shown in FIG. 14A, with respect to a BB cross-section line passing through the rotation center of the rotor,
Using two inner stators 32, 36 of the same shape in which the positions of the projections 32a, 36a formed at four locations are line-symmetric, the pole teeth bent in only one direction are directed in opposite directions to each other, and the back surface is turned. Together, the projections 32a and 36a, which are symmetrical with respect to the BB section line, are fixed together to form an integrated inner stator. Next, coil 3
3, 37, and the integrated inner stators 32, 3
6 is held between the outer stators 31 and 35.
At this time, as shown in FIG.
Notches 31a and 35a are provided at positions corresponding to the projections 32a and 36a on the outer peripheral portion of 35. Protrusion 32
Since the shape of the projections 36a is the same as that of the projections 36a and the projections are aligned and fixed, the positions of the notches 31a and 35a also match. Further, each of the projections 32a, 36a is
1a and 35a, and the positioning in the circumferential direction and the position holding in the axial direction are simultaneously performed. In this fitting, the depth T2 of the notches 31a, 35a is determined by considering the variation of the plate thickness T1 of the inner stators 32, 36 as T1 <T.
And 2.

[0004]

However, in such a stator structure, the projections 32a, 32a, 32b, 32c, between the notch depth T2 and the plate thickness T1 satisfies T1 <T2. Since the inner stator 36a can move freely in the axial direction, the integrated inner stators 32 and 36 cannot be held at the axial center of the gap G and are biased to one side (see FIG. 16). For this reason, where the line L where the outer stators 31 and 35 abut and the line M where the integrated inner stators 32 and 36 abut should be the same line, there is a step as shown in FIG. . That is, the integrated inner stators 32 and 36 are deviated from the center required in design. This shift is caused by the protrusions 32a and 36a of the integrated inner stator being cutouts 3 of the outer stator.
In the case where it is different at all four places fitted to 1a and 35a,
Both inner stators 32 and 36 are both outer stators 31 and 35
It is oblique to. At this time, since the integrated inner stators 32 and 36 are formed with pole teeth, the pole teeth on one side bite toward the center by being inclined, and the effective inner diameter is reduced. As a result, the gap between the rotor 39 and the inner stators 32 and 36 becomes smaller than the design value, and it is not possible to obtain a small motor as designed. Also, this displacement is caused by the protrusions 32a, 36 of the integrated inner stator.
Even if a is the same at all four locations fitted in the notches 31a and 35a of the outer stator, the expected performance of the motor cannot be obtained because of the misalignment.

[0005] It is an object of the present invention to provide a small motor in which an integrated inner stator can be accurately held at a center required by design.

[0006]

In order to achieve the above object, the invention according to claim 1 is directed to a first outer stator constituting a motor case and a first inner stator housed inside the motor. A first stator set having a winding coil therebetween, and a second stator having a winding coil between a second outer stator constituting a case of the motor and a second inner stator housed inside the motor. A small stator having a configuration in which the stator sets are overlapped such that both inner stators are located between the winding coils of the first stator set and the winding coils of the second stator set ; Inner stay
The first inner stator and the second inner stator are integrated, and the first stator set has a first holding portion for holding the position of the second inner stator, and the second stator set has the first inner stator. Forming a second holding portion for holding the position , the first stator
The first stator is set by overlapping the set and the second stator set.
The second inner stay is provided by the first holding part formed in the data set.
Data is held and formed in the second stator set
The first inner stator is positioned at the same time by the
Is fixed and integrated with the line L where both outer stators abut.
With the same line M that the inner stator contacts
It is.

Therefore, when the first stator set and the second stator set are overlapped, the first holding portion of the first stator set holds the second inner stator, and the second holding member of the second stator set. A holding part holds the first inner stator. For this reason, both inner stators are positioned and held at intermediate positions between the winding coils of each stator set. That is, both outer
The inner stator integrated with the line L that the stator contacts
It is positioned and maintained with the tangent line M being the same line.
Be held.

According to a second aspect of the present invention, the first holding portion is provided on the first outer stator, the second holding portion is provided on the second outer stator, and the first holding portion is formed on the first outer stator. The holding portion holds the position of the second inner stator, while the second holding portion formed on the second outer stator holds the position of the first inner stator.

Therefore, the first holding portion formed on the first outer stator holds the position of the second inner stator, and the second holding portion formed on the second outer stator holds the position of the first inner stator. Because of the holding, each inner stator is positioned at an intermediate position between each winding coil.

According to the third aspect of the present invention, the first and second inner stators and the first and second outer stators each have pole teeth facing the rotor. Therefore, in each stator set, the pole teeth are alternately arranged while facing the rotor.

According to the fourth aspect of the present invention, a projection is formed on the outer periphery of the first and second inner stators, and when the projections formed on the first and second inner stators are overlapped, Providing a non-overlapping portion where the protrusion formed on the one inner stator and the protrusion formed on the second inner stator do not overlap, and forming the non-overlapping portion of the protrusion on the second inner stator on the first outer stator And the non-overlapping portion of the projection of the first inner stator is held in contact with the second holding portion formed on the second outer stator.

Therefore, the first holding portion abuts on the non-overlapping portion of the second inner stator to hold the position of the second inner stator, and the second holding portion makes contact with the non-overlapping portion of the first inner stator. To maintain the position of the first inner stator, so that each inner stator is positioned at an intermediate position between the winding coils.

According to the fifth aspect of the present invention, the first and second outer stators are formed by a cup-shaped motor case, and are held on the outer periphery of the cup-shaped motor case in contact with the projections. A notch is formed, and each protrusion is fitted into the notch, thereby positioning both inner stators relative to both outer stators in the circumferential direction.

Therefore, the notch formed in the motor case as the first outer stator holds the position of the projection of the second inner stator, and the notch formed in the motor case as the second outer stator. Since the position of the projection of the first inner stator is maintained, each inner stator is positioned at an intermediate position between the winding coils.

According to a sixth aspect of the present invention, there is provided a bobbin on which a winding coil is wound, a first holding portion is formed on the bobbin of the first stator set, and a bobbin of the second stator set is provided with the first holding portion. Two holding parts are formed.

Accordingly, the first holding portion formed on the bobbin of the first stator set holds the position of the second inner stator, and the second holding portion formed on the bobbin of the second stator set has the first holding portion. Since the position of the inner stator is maintained, each inner stator is positioned at an intermediate position between the winding coils.

According to the seventh aspect of the present invention, the first and second inner stators and the first and second outer stators each have pole teeth facing the rotor. Therefore, in each stator set, the pole teeth are alternately arranged while facing the rotor.

Further, the invention according to claim 8 is characterized in that the two inner stators are overlapped and integrated, and when the first inner stator is held in contact with the second outer stator, the second inner stator is It is held in contact with the first outer stator. Therefore, both inner stators can be handled integrally, and it is not necessary to handle them separately.

[0019]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The structure of the present invention will be described below in detail based on an embodiment shown in the drawings.

FIGS. 1 to 6 show a first embodiment of a small motor according to the present invention. This small motor is a small stepping motor similar to the conventional example, and the basic structure of the stator is shown in FIG.
3 has the same structure as the conventional one. That is,
A first coil in which a winding coil 3 wound around a coil bobbin 10 is sandwiched between a first outer stator 1 having a pole tooth 1b and constituting an outer periphery of a motor case and a first inner stator 2 having a pole tooth 2b. Wound coil wound around the coil bobbin 11 between the stator set 4 and the second outer stator 5 having the pole teeth 5b and constituting the outer periphery of the motor case and the second inner stator 6 having the pole teeth 6b. The inner stators 2 and 6 of the second stator set 8 sandwiching 7 are overlapped with each other so as to be located between the winding coil 3 and the winding coil 7 to form a stator structure. I have. The pole teeth 1b, 2 are located at the center of the stator structure.
A rotor 9 is arranged to face b, 5b, 6b.

This stator structure is formed as follows. First, as shown in FIG. 3A, the protrusions 2a, 6
The inner stators 2 and 6 where the position a is not line-symmetric are formed. Each of the inner stators 2 and 6 has a plurality of protrusions 2a and 6a, a plurality of pole teeth 2b and 6b, a plurality of engagement holes 2c and 6c, a plurality of engagement protrusions 2d and 6d, and a plurality of bobbin rotations. The blocking holes 2e and 6e are formed. And
The back surfaces of the inner stators 2 and 6 are overlapped so that the pole teeth 2b and 6b bent only in one direction are directed in opposite directions.
Are fixed to the engaging hole 6c of the inner stator 6 and the engaging protrusion 6d of the inner stator 6 is fixed to the engaging hole 2c of the inner stator 2 (see FIG. 4). At this time, since the positions of the protrusions 2a and 6a are not line-symmetric, the protrusions 2a and 6a
Non-overlapping portions 2X and 6X that do not partially overlap with 6a are generated.

Next, the small projections (not shown) provided on the bobbins 10, 11 are inserted into the bobbin rotation preventing holes 2e, 6e of the inner stators 2, 6, respectively.
11 is superimposed on the stators 2 and 6. As shown in FIG. 1, wound coils 3 and 7 are wound around bobbins 10 and 11, respectively. That is, each bobbin 10, 11
Holds the winding coil 3 or 7. Thereafter, these are sandwiched and held between the outer stators 1 and 5.

The outer stators 1, 5 have a plurality of notches 1a corresponding to the plurality of protrusions 2a or a plurality of notches 5a corresponding to the plurality of protrusions 6a, and the bobbin 1
Large notches 1c and 5c are formed with the terminal portions 10a, 11a and the like formed at 0 and 11, respectively. Also,
As shown in FIG. 1, the plurality of notches 1a formed in the outer stator 1 are arranged at positions corresponding to the plurality of protrusions 2a of the inner stator so as to substantially coincide with the circumferential length of the protrusion 2a. The portion 2a is formed to be deeper than the axial thickness by the gap G. On the other hand, a plurality of notches 5a formed in the outer stator 5 also have a plurality of protrusions 6 of the inner stator.
At the position corresponding to a, the protrusion 6a is formed to have a length substantially in the circumferential direction and to be deeper by the gap G than the axial thickness of the protrusion 6a.

Therefore, by stacking the upper and lower stator sets such that both inner stators 2 and 6 are located between the winding coil 3 and the winding coil 7, the above-mentioned protrusions 2a and
Non-overlapping portions 2X, 6X that do not partially overlap 6a abut against the opposed outer stators 5, 1 respectively, thereby maintaining the axial position. At this time, the non-overlapping portion 2 of the projection 2a
The contact portion of the second outer stator 5 with which X contacts is referred to as a second holding portion 5d, and the contact portion of the first outer stator 1 with which the non-overlapping portion 6X of the protrusion 6a contacts is referred to as a first holding portion 1d. I have. The positioning of the inner stators 2 and 6 in the circumferential direction by the outer stators 1 and 5 will be described in detail later. This is performed by fitting the projections 2a, 6a provided on the base 6 with each other.

In this fitting, the notches 1a, 5
The depth T2 of a is set so as to satisfy the relationship of T1 <T2 in the same manner as in the prior art in consideration of the variation in the thickness T1 of each of the inner stators 2 and 6. For this reason, each notch 1a,
Although a gap G is generated at the back of the protrusion 5a, the non-overlapping portion 2X of the protrusion 2a is held by the second holding portion 5d, and the protrusion 6a
The non-overlapping portion 6X is held by the first holding portion 1d, so that the inner stators 2, 6 are fixed to each other, and the axial position is held while equally generating a gap G on both sides.

The two projections 2a, 6a also perform positioning in the circumferential direction in addition to holding the position in the axial direction. That is, the circumferential lengths of the projections 2a, 6a are notches 1a,
Since the length of the protrusion 5a is substantially the same as the circumferential length, when the projections 2a and 6a are fitted into the notches 1a and 5a, there is almost no circumferential play (= gap). Therefore, each of the inner stators 2 and 6 is connected to each of the outer stators 1 and 5.
, Cannot rotate in the circumferential direction, and positioning in the circumferential direction is performed. It should be noted that the positioning in the circumferential direction is preferably performed at a single location because there may be a case where it is difficult to obtain dimensional accuracy if there are several locations.

In this embodiment, the projection 2a of the inner stator 2 is brought into contact with the outer stator 5, while the projection 6a of the inner stator 6 is brought into contact with the outer stator 1 to maintain the axial position. Therefore, the line L where the outer stators 1 and 5 abut and the line M where the inner stators 2 and 6 abut are the same line. As a result, both inner stators 2 and 6 are accurately held at the design center. That is, the compact module of the present invention
The motor is the first outer stator that constitutes the motor case.
1 and a first inner stator 2 housed inside the motor.
A first stator set 4 having a winding coil 3 between the
Outer stator 5 and motor constituting a motor case
Between the second inner stator 6 housed inside
The second stator set 8 having the coil 7 is connected to both inner stators.
Are connected to the winding coil 3 of the first stator set 4
So as to be located between the winding coils 7 of the two stator sets 8.
Having a configuration superimposed on the first inner side
The stator 2 and the second inner stator 6 are integrated and
Position of the second inner stator 6 in the first stator set 4
A first holding part 1d for holding is formed, and a second stator set is formed.
8 a second holding portion for holding the position of the first inner stator 2
5d, the first stator set 4 and the second stator set
8 to form a first stator set 4 by overlapping
The second inner stator 6 is positioned by the first holding portion 1d.
Held and formed on the second stator set 8
The first inner stator 2 is simultaneously positioned by the holding portion 5d.
Is held, and coincides with the line L where the outer stators 1 and 5 abut.
The line M with which the internalized stators 2 and 6 come into contact is the same line
It becomes something. In the small motor of the first embodiment,
While providing one holding portion 1d on the first outer stator 1,
The second holding portion 5d is provided on the second outer stator 5, and
The first holding part 1d formed on the outer stator 1 is
While maintaining the position of the stator 6, the second outer stator
5 formed on the first inner stator 2
The position is maintained. In this case, as shown in FIG.
As described above, the outer surfaces of the first and second inner stators 2 and 6
Forming first and second inner stators 2a and 6a;
When the projections 2a, 6a formed on the parts 2, 6 are overlapped
The protrusion 2a formed on the first inner stator 2 and the second
No overlap with al and projections 6a formed in the inner stator 6
The non-overlap portions 2X and 6X are provided, and the second inner stator 6
The non-overlapping portion 6X of the projection 6a is attached to the first outer stator 1.
The first inner holding portion 1d is held in contact with the first inner
The non-overlapping portion 2X of the projection 2a of the stator 2 is
The second holding part 5d formed on the stator 5 is held in contact with the second holding part 5d.
ing. In addition, the first and second motors constituting the outer periphery of the motor case are formed.
The outer peripheral portions of the outer stators 1 and 5 are provided with projections 2a and 6a.
Notches 1a and 5a are formed to be held in contact with
Fitting the parts 2a, 6a into the notches 1a, 5a
The inner stators with respect to the outer stators 1 and 5
Positioning in the circumferential direction of 2, 6 is performed. Further
First and second inner stators 2, 6 and first and second
Are opposed to the rotor 9 with the outer stators 1 and 5, respectively.
Pole teeth 2b, 6b, 1b, 5b are formed. So
Then, as shown in FIG.
The first inner stator 2 is connected to the second outer stator
When held against the stator 5, the second inner side
The stator 6 is held in contact with the first outer stator 1
ing.

In this embodiment, as shown in FIG.
Two of the plurality of notches 1a of one outer stator 1 are formed so that both adjacent ends are continuous with the large notch 1c, and the other outer stator 5 is similarly formed of the plurality of notches 5a. The two are formed such that the ends on the adjacent side are both continuous with the large cutout portion 5c. That is, the fitting of the projections 2a, 6a and the notches 1a, 5a is arranged at uneven intervals in the circumferential direction. However, if the fittings are arranged at equal intervals in the circumferential direction as in the following second embodiment shown in FIGS. 7 to 10, it becomes more preferable in terms of precision of a small motor.

The basic configuration of the second embodiment is the same as that of the first embodiment, except for the shapes and installation positions of the projections 2a and 6a and the shapes and installation positions of the notches 1a and 5a. is there. In the description, the same members as in the first embodiment are
The same reference numerals are used.

In the second embodiment, as shown in FIG. 7, three protrusions 2a, 6a having the same shape are provided on the inner stators 2, 6 at intervals of 120 degrees. In addition, the positions of the projections 2a and 6a are determined by B
-Not line symmetric with respect to the B section line. Further, as shown in FIG. 9, notches 1a and 5a having the same shape are respectively formed on the outer stators 1 and 5 at positions corresponding to the protrusions 2a and 6a.
Three are provided at intervals of 20 degrees. As a result, on the outer peripheral portion of the small motor, three fitting states of the projections 2a, 6a and the notches 1a, 5a, which are displaced in the upper and lower stator groups shown in the enlarged view of FIG. You can do it.

As shown in FIG. 8, the two inner stators 2 and 6 are arranged such that the pole teeth bent only in one direction are directed in opposite directions to each other, and the back surfaces are overlapped with each other. The parts 2a and 6a are fixed together and integrated. At this time, in the second embodiment, the non-overlapping portions 2X and 6X are provided at all the overlapping projections, and the axial positions of the inner stators 2 and 6 are provided at all the overlapping projections. Holding can be performed reliably, and there is an effect of further improving the accuracy of the small motor.

The positioning in the circumferential direction by the outer stators 1 and 5 is the same as in the first embodiment, and a description thereof will be omitted. Also, the protrusions 2 arranged at equal intervals
The number of a and 6a may be two instead of three, or four or more. For example, the protrusions 2a, 6
If the width of “a” is increased, the strength and the like are sufficient, and each of them can be two.

Next, a third embodiment will be described with reference to FIG. In this embodiment, when the configuration of the related art shown in FIGS. 13 to 16 is used, the integrated inner stators 32 and 36 are not held at the axial center of the gap G and are not biased to one side. A portion corresponding to the second holding portion 5d shown in the first embodiment is provided on the bobbin 11, and the first holding portion 1
This is an example in which a portion corresponding to d is provided on the bobbin 10. In the description, the same members as those in the related art are denoted by the same reference numerals.

In the third embodiment, although the detailed description is omitted because it is the same as the configuration of the prior art, the inner stators 32 and 36 are fixed with their back surfaces overlapping each other, and the bobbin of the upper stator set is fixed. 10, three position holding projections 10b for holding the inner stator 36 in the axial direction are provided, and three position holding projections 11b for holding the inner stator 32 in the axial direction are provided on the bobbin 11 of the other lower stator set. here,
Each position holding protrusion 10b of the bobbin 10 corresponds to the first holding portion 1d of the first embodiment, and each position holding protrusion 1b of the bobbin 11
Reference numeral 1b corresponds to the second holding portion 5d of the first embodiment.

The inner stator 32 has a plurality of holes 32f through which the position holding projections 10b pass.
Is provided at a position corresponding to. Then, each of the position holding protrusions 10b is abutted against the flat plate portion of the other inner stator 36. Conversely, the inner stator 36 of the lower stator set is connected to the position holding protrusion 10 of the bobbin 10 of the upper stator set.
The position in the axial direction is regulated by b. on the other hand,
The inner stator 36 is provided with a plurality of holes 36f through which the position holding projections 11b pass, at positions corresponding to the respective projections 11b. Each of the position holding projections 11b also abuts against the flat plate portion of the inner stator 32. Conversely,
The axial position of the inner stator 32 of the upper stator set is also regulated by the position holding projections 11b of the bobbin 11 of the lower stator set. That is, the small model of the third embodiment
The bobbins 10, 11 on which the winding coils 3, 7 are wound
And the first holding portion is attached to the bobbin 10 of the first stator set 4.
The position holding projection 10b corresponding to 1d is formed, and the second
The bobbin 11 of the data set 8 has a position corresponding to the second holding portion 5d.
The holding projection 11b is formed. In addition,
And second inner stators 32, 36 and first and second outer stators
The stators 31 and 35 face the rotor 39, respectively.
Pole teeth 32b, 36b, 31b, 35b are formed
I have.

Each of the above embodiments is an example of a preferred embodiment of the present invention. However, the present invention is not limited thereto, and various modifications can be made without departing from the gist of the present invention. For example, instead of providing the first and second holding portions on the outer stator and the bobbin, the first and second holding portions may be provided on a dedicated plate for position holding provided on the outer stator. Also, as shown in FIG.
It may be arranged that no overlap with a occurs. Furthermore,
The number of projections 2a, 6a and notches 1a, 5a may be at least one for each of the stators 1, 2, 5, 6, but it is preferable to provide a plurality of each in consideration of assembly accuracy. In addition, it is most preferable in terms of assembling accuracy if the installation positions are arranged at equal intervals in the circumferential direction.

Further, in each embodiment, an example of a small stepping motor has been described, but the present invention can be applied to a small motor in general having a stator structure in which a plurality of stator sets each including two upper and lower stators are stacked.

[0038]

As is apparent from the above description, the first aspect of the present invention provides the first inner stator and the second inner stator.
Over data are integrated, the first to the second of the first holding portion is formed to a position holding the inner stator, holding the position the first inner stator to the second stator assembly to the first stator assembly Forming two holding parts , the first stator set and the second stator
The first stator set was formed by overlapping the sets
The second inner stator is held in position by the first holder.
And the second holding part formed in the second stator set
The first inner stator is simultaneously held in position,
The inner stator integrated with the line L that the side stator contacts
Since the contacting line M is the same line, when the first stator set and the second stator set are overlapped, both inner stators are positioned and held at intermediate positions between the winding coils of each stator set. . As a result, both inner stators can be accurately held at the center of design, and the inner stator is not held obliquely with respect to other members such as the outer stator and the bobbin. Is as designed, and a small motor as designed can be obtained.

According to a second aspect of the present invention, the first holding portion is provided on the first outer stator, the second holding portion is provided on the second outer stator, and the first holding portion is formed on the first outer stator. While the holding portion holds the position of the second inner stator, the second holding portion formed on the second outer stator holds the position of the first inner stator. The holding portion holds the position of the second inner stator, and the second holding portion formed on the second outer stator holds the position of the first inner stator. Thereby, each inner stator can be positioned with high accuracy at an intermediate position between the respective winding coils.

According to the third aspect of the present invention, the first and second inner stators and the first and second outer stators each have pole teeth facing the rotor. In the set, the pole teeth can be arranged alternately while facing the rotor.

According to the fourth aspect of the present invention, the protrusions are formed on the outer periphery of the first and second inner stators, and when the protrusions formed on the first and second inner stators are overlapped, Providing a non-overlapping portion where the protrusion formed on the one inner stator and the protrusion formed on the second inner stator do not overlap, and forming the non-overlapping portion of the protrusion on the second inner stator on the first outer stator The first holding portion is held in contact with the first holding portion, and the non-overlapping portion of the projection of the first inner stator is held in contact with the second holding portion formed on the second outer stator. The portion abuts against the non-overlapping portion of the second inner stator to hold the position of the second inner stator, and the second holding portion abuts against the non-overlapping portion of the first inner stator to maintain the position of the first inner stator. Holds the position of the stator. As a result, each inner stator can be positioned at an intermediate position between each winding coil with high accuracy.

According to the fifth aspect of the present invention, the first and second outer stators are formed by a cup-shaped motor case, and are held on the outer peripheral portion of the cup-shaped motor case in contact with the projections. A notch is formed, and each projection is fitted into the notch, thereby positioning the inner stator in the circumferential direction with respect to the outer stator, so that the motor case is the first outer stator. The formed notch holds the position of the protrusion of the second inner stator, and the notch formed in the motor case, which is the second outer stator, holds the position of the protrusion of the first inner stator. As a result, each inner stator can be positioned at an intermediate position between each winding coil with high accuracy.

According to a sixth aspect of the present invention, there is provided a bobbin on which a winding coil is wound, a first holding portion is formed on the bobbin of the first stator set, and a first holding portion is formed on the bobbin of the second stator set. Since the two holding portions are formed, the first holding portion formed on the bobbin of the first stator set holds the position of the second inner stator, and the second holding portion formed on the bobbin of the second stator set. Performs the position holding of the first inner stator. Thereby, each inner stator can be positioned with high accuracy at an intermediate position between the respective winding coils.

According to the seventh aspect of the present invention, the first and second inner stators and the first and second outer stators each have pole teeth facing the rotor. In the set, the pole teeth can be arranged alternately while facing the rotor.

Further, the invention according to claim 8 is characterized in that both inner stators are overlapped and integrated, and when the first inner stator is held in contact with the second outer stator, the second inner stator is Since the first inner stator is held in contact with the first outer stator, both inner stators can be handled as a single unit. As a result, it is easy to assemble the small motor, and the manufacturing cost can be reduced.

[Brief description of the drawings]

FIG. 1 is a side view and a main part enlarged view of a first embodiment of the present invention.

FIG. 2 is a front view of the first embodiment of the present invention.

3A and 3B are diagrams showing an inner stator according to a first embodiment of the present invention, wherein FIG. 3A is a plan view thereof, and FIG. 3B is a sectional view taken along line BB of FIG.

4A and 4B are diagrams showing a state in which the inner stator according to the first embodiment of the present invention is superimposed, wherein FIG. 4A is a plan view thereof and FIG.
FIG. 3 is a sectional view taken along line BB of FIG.

5A and 5B are views showing an outer stator according to the first embodiment of the present invention, wherein FIG. 5A is a plan view thereof, and FIG. 5B is a sectional view taken along line BB of FIG.

FIG. 6 is a front view of the outer stator according to the first embodiment of the present invention.

FIG. 7 is a plan view of an inner stator according to a second embodiment of the present invention.

FIG. 8 is a plan view showing a state where the inner stator according to the second embodiment of the present invention is overlaid.

9A and 9B are views showing an outer stator according to a second embodiment of the present invention, wherein FIG. 9A is a plan view thereof, and FIG. 9B is a front view in which pole teeth are omitted.

FIG. 10 is a side view and a main part enlarged view of a second embodiment of the present invention.

FIG. 11 is an exploded view of a main part for describing a third embodiment of the present invention.

FIG. 12 is a side view and a main part enlarged view of a fourth embodiment of the present invention.

FIG. 13 is a diagram for explaining a basic configuration of the related art and the present invention.

14A and 14B are views showing a conventional inner stator, wherein FIG. 14A is a plan view thereof, and FIG. 14B is a sectional view taken along line BB of FIG. 14A.

FIG. 15 is a side view of a conventional small motor and an enlarged view of a main part thereof.

FIG. 16 is an enlarged view of a main part for describing a problem of a conventional small motor.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 first outer stator 1a notch 1b pole tooth 1d first holding part 2 first inner stator 2a protrusion 2b pole tooth 2X non-overlapping part 3 winding coil 4 first stator set 5 second outer stator 5a Notch 5b Pole 5d Second holding part 6 Second inner stator 6a Projection 6b Pole 6X Non-overlapping part 7 Winding coil 8 Second stator set 9 Rotor 10, 11 Coil bobbin

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-63-253849 (JP, A) JP-A-2-17856 (JP, A) JP-A-59-53079 (JP, A) JP-A-50- 140807 (JP, A) Japanese Utility Model 60-93487 (JP, U) Japanese Utility Model 1-157577 (JP, U) Japanese Utility Model 58-112053 (JP, U) (58) Field surveyed (Int. ⁷ , DB name) H02K 37/14

Claims (8)

(57) [Claims] 1. A first stator set having a winding coil between a first outer stator forming a case of a motor and a first inner stator housed inside the motor, and forming a case of the motor. A second stator set having a winding coil between a second outer stator and a second inner stator housed inside the motor; A small motor having a configuration in which the first inner stay is positioned between a coil and a winding coil of the second stator set;
And the second inner stator are integrated, and a first holding part for holding the position of the second inner stator is formed in the first stator set, and a first holding part is provided in the second stator set. Forming a second holding portion for holding the position of the inner stator, and stacking the first stator set and the second stator set.
The first stator set formed by combining
The second inner stator is held in position by one holding portion.
And the second stator set
The first inner stator is simultaneously held in position by the holding portion.
And integrated with the line L where both outer stators abut
A small motor, wherein a line M with which the inner stator abuts is the same line . 2. The method according to claim 1, wherein the first holding portion is provided on the first outer stator, and the second holding portion is provided on the second outer stator. The second holding portion formed on the second outer stator holds the position of the first inner stator, while holding the position of the second inner stator. Small motor. 3. The small motor according to claim 2, wherein the first and second inner stators and the first and second outer stators each have pole teeth facing a rotor. . 4. When the projections are formed on the outer periphery of the first and second inner stators and the projections formed on the first and second inner stators are overlapped, the first inner stator is formed. A non-overlapping portion where the projection formed on the second inner stator does not overlap with the projection formed on the second inner stator, and the non-overlapping portion of the projection of the second inner stator is formed on the first outer stator. And holding the non-overlapping portion of the projection of the first inner stator against the second holding portion formed on the second outer stator. The small motor according to any one of claims 1 to 3. 5. A method according to claim 1, wherein the first and second outer stators are formed by a cup-shaped motor case, and a notch is formed in an outer peripheral portion of the cup-shaped motor case so as to be in contact with the projection and hold the protrusion. 5. The small-sized motor according to claim 4, wherein the projections are fitted in the notches to position the inner stators relative to the outer stators in the circumferential direction. 6. A bobbin on which the winding coil is wound, a first holding portion is formed on the bobbin of the first stator set, and a second holding portion is formed on the bobbin of the second stator set. The small motor according to claim 1, wherein: 7. The small motor according to claim 6, wherein the first and second inner stators and the first and second outer stators each have pole teeth facing a rotor. . 8. When the two inner stators are overlapped and integrated, and the first inner stator is held in contact with the second outer stator, the second inner stator becomes the first inner stator. The small motor according to any one of claims 1 to 5, wherein the small motor is held in contact with the outer stator.