Patent Description:
As one mode of a stator used for a generator and an electric motor, there is known a stator including a stator core having a plurality of teeth arranged radially and two insulators sandwiching the stator core from above and below (for example, see <CIT>). Each tooth of the stator core is covered with the respective insulators, and a coil wire is wound therearound to form a coil. As a result, the respective insulators is interposed between the tooth and the coil to insulate the tooth from the coil. When the two insulators sandwich the stator core therebetween, insertion portions that project from each insulator cover each tooth, and at this time, each insertion portions is inserted into a slot between two adjacent teeth.

However, in recent years, the number of teeth of a stator core has increased in response to an increase in required electromotive force and required output. Therefore, a slot becomes smaller and ease of insertion of each insertion portion into each slot is lowered. In addition, since the number of slots has increased, when each insertion portion is inserted into each slot, rubbing of each insertion portion and each tooth often occurs, and again, ease of insertion of each insertion portion into each slot is lowered. As a result, work efficiency of mounting two insulators to a stator core is lowered.

The present invention is an insulator set as defined in the independent claim <NUM>. Further embodiments of the invention are defined in the dependent claims <NUM> - <NUM>.

Provided is an insulator set including a first insulator and a second insulator that sandwich a stator core therebetween. The stator core includes a plurality of teeth that radially projects from a center portion of the stator core. The first insulator includes a plurality of first tooth covering portions that radially projects from a center portion of the first insulator. The second insulator has a plurality of second tooth covering portions that radially projects from a center portion of the second insulator. The plurality of first tooth covering portions and the plurality of second tooth covering portions cover the plurality of teeth. In a facing portion of the first insulator that faces the second insulator, a peripheral portion of the first insulator projects more than the center portion of the first insulator. In a facing portion of the second insulator that faces the first insulator, the center portion of the second insulator projects more than a peripheral portion of the second insulator.

The peripheral portion projects more than the center portion in the facing portion of the first insulator facing the second insulator. Therefore, when the first insulator is mounted to the stator core, first, the peripheral portion is inserted into the stator core, and functions as a guide. Furthermore, the center portion projects more than the peripheral portion in the facing portion of the second insulator facing the first insulator. Therefore, when the second insulator is mounted to the stator core, first, the center portion is inserted into the stator core, and functions as a guide. As a result, work efficiency of mounting the first insulator and the second insulator to the stator core can be improved.

<FIG> is a perspective view schematically showing a structure of a stator according to the present embodiment. <FIG> is an exploded perspective view indicating the structure of the stator according to the present embodiment. It should be noted that, in <FIG>, illustration of a coil <NUM> described later is omitted.

In <FIG> and <FIG>, a stator <NUM> includes a stator core <NUM> and insulators <NUM>, <NUM> (first insulator, second insulator) that sandwich the stator core <NUM> therebetween. The stator core <NUM> is a laminated body of thin metal plates, and includes a center portion 11a that has a substantially cylindrical shape, and teeth 11b, which are a plurality of yokes that projects from the center portion 11a radially with respect to a center axis of the center portion 11a.

The insulator <NUM> mounted from one side to the stator core <NUM> includes a center portion 12a and a plurality of tooth covering portions 12b (first tooth covering portions) each having a substantially U-shaped cross section and projecting from the center portion 12a correspondingly to each tooth 11b. Furthermore, the insulator <NUM> mounted from the other side to the stator core <NUM> includes a center portion 13a and a plurality of tooth covering portions 13b (second tooth covering portions) each having a substantially U-shaped cross section and projecting from the center portion 13a correspondingly to each tooth 11b. The insulator <NUM> and the insulator <NUM> form an insulator set.

When the insulators <NUM>, <NUM> sandwich the stator core <NUM> therebetween, the teeth 11b are covered with the tooth covering portions 12b, 13b. A coil wire is wound around the tooth 11b covered with the tooth covering portions 12b, 13b to form the coil <NUM>. Therefore, the tooth covering portions 12b, 13b are interposed between the coil <NUM> and the tooth 11b, and the tooth 11b is insulated from the coil <NUM>.

The stator <NUM> is covered with a rotor (not shown) that is a rotatable cover. A plurality of magnets is arranged inside a side wall surface of the rotor so as to face the teeth 11b, respectively. In a case where the stator <NUM> is used for an electric motor, a magnetic field is generated by energizing each coil <NUM>, and the rotor is rotated around the center axis of the center portion 11a of the stator core <NUM> due to interaction between the generated magnetic field and the magnetic field of each magnet of the rotor. In a case where the stator <NUM> is used for a generator, the rotor rotates around the center axis of the center portion 11a of the stator core <NUM>. As a result, an induced current due to the magnetic field of each magnet is generated in each coil <NUM>.

Furthermore, an end portion 11c of each tooth 11b in a radial direction of the stator core <NUM> is not covered with the tooth covering portion 12b and the tooth covering portion 13b, but is exposed to each magnet of the rotor. As a result, the magnetic field generated by each tooth 11b and the magnetic field generated by each magnet are efficiently interacted with each other.

<FIG> is a cross-sectional view of the stator core <NUM> and the insulators <NUM>, <NUM> taken along a line III-III in <FIG>.

In <FIG>, in a facing portion 12c of the insulator <NUM> facing the insulator <NUM> (facing portion facing the second insulator), a peripheral portion 12d projects toward the insulator <NUM> more than the center portion 12a. In a facing portion 13c of the insulator <NUM> facing the insulator <NUM> (facing portion facing the first insulator), the center portion 13a projects toward the insulator <NUM> more than a peripheral portion 13d. That is, the facing portion 12c of the insulator <NUM> is recessed in a substantially mortar shape, and the facing portion 13c of the insulator <NUM> projects in a substantially truncated cone shape.

The facing portion 12c of the insulator <NUM> is uniformly inclined from the center portion 12a toward the peripheral portion 12d. An inclination angle of the facing portion 12c of the insulator <NUM>, that is, an inclination angle θ1 from the peripheral portion 12d to the center portion 12a is set to <NUM>° or less, and preferably set to <NUM>°. The facing portion 13c of the insulator <NUM> is also uniformly inclined from the center portion 13a to the peripheral portion 13d. An inclination angle of the facing portion 13c of the insulator <NUM>, that is, an inclination angle θ2 from the center portion 13a to the peripheral portion 13d is set to <NUM>° or less, and preferably set to <NUM>°.

It should be noted that the facing portion 12c faces the stator core <NUM> when the insulator <NUM> is mounted to the stator core <NUM>, and the facing portion 13c faces the stator core <NUM> when the insulator <NUM> is mounted to the stator core <NUM>.

As indicated by arrows in <FIG>, when the insulators <NUM>, <NUM> are mounted to the stator core <NUM> so as to sandwich the stator core <NUM> therebetween, as described above, in the facing portion 12c of the insulator <NUM>, the peripheral portion 12d projects. Therefore, first, the peripheral portion 12d engages with the stator core <NUM> (<FIG>). At this time, a part (the lowermost end portion in the figure) of each tooth covering portion 12b located in the peripheral portion 12d engages with the corresponding tooth 11b. Further, as the insulator <NUM> moves toward the insulator <NUM>, a part of each tooth covering portion 12b slides on a side surface of the tooth 11b and functions as a guide for the tooth 11b. Since the center portion 13a projects in the facing portion 13c of the insulator <NUM>, first, the center portion 13a engages with the stator core <NUM> (<FIG>). At this time, a part (the uppermost end portion in the figure) of each tooth covering portion 13b located in the center portion 13a engages with the corresponding tooth 11b. Further, as the insulator <NUM> moves toward the insulator <NUM>, a part of each tooth covering portion 13b slides on the side surface of the tooth 11b and functions as a guide for the tooth 11b. As a result, work efficiency of mounting the insulator <NUM> and the insulator <NUM> to the stator core <NUM> can be improved. Finally, the facing portion 12c of the insulator <NUM> and the facing portion 13c of the insulator <NUM>, which are mounted to the stator core <NUM>, abut against each other.

<FIG>, <FIG> and <FIG> are perspective views showing the configurations of the tooth covering portion 12b of the insulator <NUM> and the tooth covering portion 13b of the insulator <NUM>. <FIG> and <FIG> are front views showing the configurations of the tooth covering portion 12b of the insulator <NUM> and the tooth covering portion 13b of the insulator <NUM>. Each of <FIG>, <FIG>, <FIG>, <FIG>, and <FIG> shows only one tooth covering portion 12b and one tooth covering portion 13b.

In each of <FIG>, <FIG>, <FIG>, <FIG>, and <FIG>, the tooth covering portion 12b is a cover having a substantially rectangular tube shape projecting from the center portion 12a, and partially opened so as to be able to accommodate a part of the tooth 11b therein. Also, the tooth covering portion 13b is a cover having a substantially rectangular tube shape projecting from the center portion 13a, and partially opened so as to be able to accommodate a part of the tooth 11b therein (<FIG>, <FIG>, and <FIG>).

As described above, the facing portion 12c of the insulator <NUM> is recessed in a substantially mortar shape, and is uniformly inclined from the center portion 12a toward the peripheral portion 12d. Therefore, also a facing portion (hereinafter simply referred to as a "lower portion") (first end portion) of the tooth covering portion 12b facing the tooth covering portion 13b is uniformly inclined from the center portion 12a to the peripheral portion 12d without forming a corner therebetween. In addition, the facing portion 13c of the insulator <NUM> projects in a substantially truncated cone shape, and is uniformly inclined from the center portion 13a toward the peripheral portion 13d. Therefore, also a facing portion (hereinafter simply referred to as an "upper portion") (second end portion) of the tooth covering portion 13b facing the tooth covering portion 12b is uniformly inclined from the center portion 13a to the peripheral portion 13d without forming a corner therebetween, correspondingly to the lower portion of the tooth covering portion 12b.

As shown in (a) in <FIG>, it is conceivable to improve ease of insertion of each insertion portion <NUM> into each slot by inclining a front end portion 70a of each insertion portion <NUM> of each insulator <NUM> for sandwiching a stator core so as to projects more as proceeding toward the center portion of each insulator <NUM>.

However, in a case where the stator core is sandwiched from above and below by the two insulators <NUM> in which the front end portion 70a of each insertion portion <NUM> that projects more as proceeding toward the center portion, a peripheral portion of each tooth <NUM> of the stator core is not covered with each insertion portion <NUM>. Therefore, the peripheral portion of each tooth <NUM> is exposed ((b) in <FIG>). As a result, there is risk that a coil wire wound around the tooth <NUM> with the insertion portion <NUM> interposed therebetween may contact the tooth <NUM> around which the coil wire is wound, and thus insulation failure occurs.

In contrast, in the present embodiment, the inclination angle from the center portion 12a to the peripheral portion 12d of the lower portion of the tooth covering portion 12b, the lower portion being uniformly inclined, and the inclination angle from the center portion 13a to the peripheral portion 13d of the upper portion of the tooth covering portion 13b, the upper portion being uniformly inclined, are set to be identical to each other. Therefore, when the insulators <NUM>, <NUM> are mounted to the stator core <NUM>, the lower portion of the tooth covering portion 12b and the upper portion of the tooth covering portion 13b abut against each other without a gap therebetween (<FIG> and <FIG>). As a result, the tooth covering portion 12b and the tooth covering portion 13b can completely cover the tooth 11b housed inside, and the insulation property of each tooth 11b of the stator core <NUM> can be improved.

The upper portion of the tooth covering portion 13b has a tapered shape that is tapered toward the tooth covering portion 12b. Specifically, a guide 13e formed by wall portions that are inwardly inclined as proceeding toward the tooth covering portion 12b is formed in the upper portion of the tooth covering portion 13b. The lower portion of the tooth covering portion 12b has a receptacle shape that widens as proceeding toward the tooth covering portion 13b correspondingly to the tapered shape of the upper portion of the tooth covering portion 13b. Specifically, a guide opening 12e formed by wall portions that are outwardly inclined as proceeding toward the tooth covering portion 13b is formed in the lower portion of the insulator <NUM>.

When the lower portion of the tooth covering portion 12b and the upper portion of the tooth covering portion 13b abut against each other, the guide 13e of the tooth covering portion 13b is inserted into the guide opening 12e of the tooth covering portion 12b. As a result, the lower portion of the tooth covering portion 12b and the upper portion of the tooth covering portion 13b can be reliably engaged, and the tooth 11b can be reliably covered. Further, it is possible to prevent the tooth covering portion 12b from being displaced with respect to the tooth covering portion 13b.

Further, since the guide 13e is tapered as proceeding toward the tooth covering portion 12b and the guide opening 12e is widened as proceeding toward the tooth covering portion 13b, the guide 13e can be easily inserted into the guide opening 12e, and thus ease of combining the insulator <NUM> and the insulator <NUM> can be improved.

The guide 13e is configured by the wall portions that are inclined inward, and the guide opening 12e is configured by the wall portions that are inclined outward. Therefore, an integrated thickness of the insulator <NUM> and the insulator <NUM> at a fitting portion where the guide 13e is fitted to the guide opening 12e can be reduced. As a result, it is possible to increase a space for winding the coil wire around the tooth 11b and increase the number of turns of the coil <NUM>.

A center-side guide 13f (see <FIG> and <FIG>) that is inclined toward the center of the insulator <NUM> as proceeding toward the tooth covering portion 12b is formed in an upper portion of the center portion 13a of the tooth covering portion 13b. A peripheral-side guide <NUM> (see <FIG> and <FIG>) that is inclined toward the periphery of the insulator <NUM> as proceeding toward the tooth covering portion 12b is formed in an upper portion of the peripheral portion 13d of the tooth covering portion 13b.

A center-side receiver 12f (see <FIG>, <FIG>, and <FIG>) that is inclined toward the periphery of the insulator <NUM> as proceeding toward the tooth covering portion 13b is formed in a lower portion of the center portion 12a of the tooth covering portion 12b. A peripheral-side receiver <NUM> (see <FIG> and <FIG>) that is inclined toward the center of the insulator <NUM> as proceeding toward the tooth covering portion 13b is formed in a lower portion of the peripheral portion 12d of the tooth covering portion 12b.

The inclination angle of the peripheral-side receiver <NUM> of the tooth covering portion 12b and the inclination angle of the peripheral-side guide <NUM> of the tooth covering portion 13b are substantially identical to each other. Therefore, when the lower portion of the tooth covering portion 12b and the upper portion of the tooth covering portion 13b abut against each other, the peripheral-side guide <NUM> guides the peripheral-side receiver <NUM>. The inclination angle of the center-side receiver 12f of the tooth covering portion 12b and the inclination angle of the center-side guide 13f of the tooth covering portion 13b are substantially identical to each other. Therefore, when the lower portion of the tooth covering portion 12b and the upper portion of the tooth covering portion 13b abut against each other, the center-side guide 13f guides the center-side receiver 12f. That is, the center-side receiver 12f, the peripheral-side receiver <NUM>, the center-side guide 13f, and the peripheral-side guide <NUM> can achieve similar effects as those of the guide opening 12e and the guide 13e.

Furthermore, in the upper portion of the center portion 13a of the tooth covering portion 13b, on the side opposite to the center-side guide 13f, that is, on the side facing the center portion 11a of the stator core <NUM>, another center-side guide <NUM> (see <FIG>) that is inclined toward the periphery of the insulator <NUM> as proceeding toward the tooth covering portion 12b is formed. Since the other center-side guide <NUM> is inclined toward the periphery of the insulator <NUM>, the other center-side guide <NUM> functions as a guide for the center portion 11a of the stator core <NUM> when the center portion 13a of the insulator <NUM> engages with the stator core <NUM>. As a result, the insulator <NUM> can be smoothly mounted to the stator core <NUM>.

The stator core <NUM> is formed by stacking a large number of thin metal plates and punching the large number of thin metal plates that are stacked by a press. Therefore, a burr 11d may be formed at one end or the other end of each tooth 11b of the stator core <NUM> (<FIG>). Here, when the insulator <NUM> is mounted from the side where the burr 11d of the stator core <NUM> is formed (<FIG>), since the guide 13e of the tooth covering portion 13b is formed by the wall portions that are inclined inward, the guide 13e and the burr 11d interfere with each other. As a result, there is risk that the insulator <NUM> is not smoothly mounted to the stator core <NUM> (<FIG>).

In the present embodiment, in order to cope with this, the insulator <NUM> is mounted from the side of the stator core <NUM> where the burr 11d is formed (<FIG>). Since the guide opening 12e of the tooth covering portion 12b of the insulator <NUM> widens as proceeding toward the tooth covering portion 13b, the burr 11d is less likely to interfere with the insulator <NUM> and the insulator <NUM> can be smoothly mounted to the stator core <NUM> (<FIG>). As a result of mounting the insulator <NUM> to the stator core <NUM>, each tooth covering portion 12b covers the side of each tooth 11b where the burr 11d is formed.

Further, as described above, the center-side receiver 12f of the tooth covering portion 12b is inclined toward the periphery of the insulator <NUM> as proceeding toward the tooth covering portion 13b. The peripheral-side receiver <NUM> of the tooth covering portion 12b is inclined toward the center of the insulator <NUM> as proceeding toward the tooth covering portion 13b. Therefore, similarly to the guide opening 12e, the center-side receiver 12f and the peripheral-side receiver <NUM> are less likely to interfere with the burr 11d, and can contribute to smooth mounting of the insulator <NUM> to the stator core <NUM>.

Although a preferred embodiment of the present invention has been described above, the present invention is not limited to the above-described embodiment, and various modifications and changes can be made within the scope of the claims.

For example, in the present embodiment, the upper portion of each tooth covering portion 13b of the insulator <NUM> has a tapered shape; however, the lower portion of each tooth covering portion 12b of the insulator <NUM> may have a tapered shape. In this case, the upper portion of each tooth covering portion 13b has a receptacle shape that widens as proceeding toward the tooth covering portion 12b. Furthermore, a guide or a guide opening may not be formed in the lower portion of each tooth covering portion 12b or the upper portion of each tooth covering portion 13b.

Moreover, in the present embodiment, the lower portion of the tooth covering portion 12b and the upper portion of the tooth covering portion 13b abut against each other without a gap therebetween. However, a gap so small that a coil wire cannot enter even if the coil wire is warped may be formed between the lower portion of the tooth covering portion 12b and the upper portion of the tooth covering portion 13b. That is, the lower portion of the tooth covering portion 12b and the upper portion of the tooth covering portion 13b do not necessarily have to abut against each other without a gap therebetween.

Claim 1:
An insulator set including a first insulator (<NUM>) and a second insulator (<NUM>) for sandwiching a stator core therebetween, wherein
the stator core includes a plurality of teeth that radially projects from a center portion of the stator core,
the first insulator includes a plurality of first tooth covering portions (12b) that radially projects from a center portion (12a) of the first insulator,
the second insulator includes a plurality of second tooth covering portions (13b) that radially projects from a center portion (13a) of the second insulator
the plurality of first tooth covering portions and the plurality of second tooth covering portions cover the plurality of teeth,
in a facing portion (12c) of the first insulator that faces the second insulator, a peripheral portion (12d) of the first insulator axially projects more towards the second insulator than the center portion of the first insulator, and
in a facing portion (13c) of the second insulator that faces the first insulator, the center portion of the second insulator axially projects more towards the first insulator than a peripheral portion (13d) of the second insulator, and
when the first insulator and the second insulator sandwich the stator core therebetween, the facing portion that faces the second insulator abuts against the facing portion that faces the first insulator,
characterised in that the facing portion (12c) of the first insulator that faces the second insulator is uniformly inclined from the center portion (12a) of the first insulator to the peripheral portion (12d) of the first insulator, and the facing portion (13c) of the second insulator that faces the first insulator is uniformly inclined from the center portion (13a) of the second insulator to the peripheral portion (13d) of the second insulator.