JP2009060754A - Core for stator, the stator, method for assembling the core and motor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a core being divided into a yoke section and a teeth section and having high performance and high reliability, and to provide a method for assembling the core, a stator utilizing the assembling method and a motor. <P>SOLUTION: The stator 10 has the core 15 consisting of the yoke sections 11 and the teeth sections 12 and a coil 13. The yoke sections 11 consist of plate ring-shaped members, and have a large number of tapered fitting holes 11a. The tapered base sections 12c of the teeth sections 12 are inserted into the fitting holes 11a of the yoke sections 11, under a state where the teeth sections 12 are cooled and shrunk, at assembling, and the fitting holes 11a and the base sections 12c are fitted firmly with the teeth sections 12 restored to room temperature. That is, the teeth sections 12 and the yoke sections 11 are connected by a cooling fit. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a stator core, a stator using the same, an assembling method thereof, and an improvement of a motor.

  In recent years, with the advancement of new technologies such as various electric devices, electric vehicles, hybrid vehicles, robots, etc., demands for higher performance, smaller size, lower costs, etc. for rotating electric machines (motors and generators) used in them have increased. ing.

  Therefore, Patent Document 1 discloses an axial motor in which a rotor is opposed to a stator in the direction of a motor rotation axis as a motor suitable for downsizing (thinning). This document discloses a structure in which a magnetic current generated by a coil is used more efficiently than a magnetic steel plate by using a powder magnetic material as a magnetic material constituting the core. In addition, the core is divided into a yoke part and a tooth part, and the bottom part of the tooth part is press-fitted into the concave part of the yoke part, thereby facilitating the manufacture and assembly of each part of the core.

JP 2005-348472 A

  By the way, when assembling parts divided into parts, care must be taken not to break them. In particular, although the dust magnetic material is excellent in manufacturability compared with a magnetic steel plate, it has low mechanical strength. Therefore, as in Patent Document 1, when the bottom portion of the tooth portion is press-fitted into the concave portion of the yoke portion, the yoke portion or the tooth portion may be damaged. On the other hand, when an adhesive is interposed, magnetic flow is hindered in the core and magnetic flux is reduced.

  An object of the present invention is to provide a high-performance and high-reliability core, a stator using the same, an assembling method thereof, and a motor while facilitating manufacture by dividing the core into a yoke portion and a tooth portion. There is to do.

  The stator core of the present invention is divided into a yoke part having a fitting hole and a stator, and the base part of the tooth part is fastened to the fitting hole of the yoke part by cold fitting.

  As a result, the yoke portion and the teeth portion are firmly connected, and the fitting hole of the yoke portion and the base portion of the teeth portion are almost entirely in contact with each other, so that the magnetic flow in the core generated by the coil is efficiently used. Can generate a lot of magnetic flux. In addition, since cold fitting is used, when the fitting hole and the base portion come into contact with each other, there is almost no impact or local stress, and there is almost no risk of breakage. Therefore, it is easy to manufacture and assemble parts, and a high-performance and highly reliable core can be obtained.

  Since the fitting hole and the base have a taper in the direction of the motor rotation axis, the allowance for the cold fitting can be controlled within an appropriate range by the relative position in the axial direction between the tooth portion and the yoke portion.

  In addition, the fitting hole and base have a taper in the radial direction, so that the tightness of the cold fitting is controlled within an appropriate range with the axial relative position of the teeth and yoke fixed. can do.

  Even if the fitting hole is a hole with a bottom, it is possible to control the tightening allowance of the cooling fitting within an appropriate range in a state where the axial relative positions of the tooth portion and the yoke portion are constant.

  Since the yoke portion has a ring-shaped integrated structure, the number of assembly parts can be reduced, and the cost can be reduced.

  A stator or motor (especially an axial motor) with high reliability can be obtained by the stator or motor using the stator core of the present invention.

  A method for assembling a stator core according to the present invention is a method for assembling a core including a yoke part and a tooth part, the main part being a dust magnetic material, and the fitting part of the yoke part in a state where the tooth part is cooled. This is a method of fastening the base portion of the teeth portion with each fitting hole of the yoke portion by returning the tooth portion to room temperature after being inserted into the base.

  If the teeth part is cooled before assembly, the dimensions of the base part of the tooth part are reduced. Therefore, at the moment when the base part of the tooth part is inserted into the fitting hole of the yoke part, the two parts are hardly in contact with each other. Gradual phase contact. When the tooth portion returns to normal temperature, the base portion is fastened to the fitting hole of the yoke portion in a strong fitting state, and the tooth portion and the yoke portion are firmly connected. At this time, since the dimensional change of the base portion that expands in accordance with the temperature change proceeds slowly, the impact force does not act on the teeth portion and the yoke portion, and the risk of breakage can be suppressed. Therefore, it is possible to easily assemble a high-performance and highly reliable stator core while facilitating the manufacture of parts.

  According to the stator core, the stator, its assembling method or the motor of the present invention, it is possible to obtain a high-performance and highly reliable core, stator or motor while facilitating the manufacture and assembly of parts.

FIG. 1 is a cross-sectional view showing a schematic structure of an axial motor MO in the embodiment. As shown in the figure, the motor MO is configured by housing a stator 10 and a rotor 20 in a motor case CA. The stator 10 includes a core 15 composed of a yoke portion 11 and a tooth portion 12 each of which is mainly made of a dust magnetic material, and a coil 13 wound around the teeth portion 12. On the other hand, the rotor 20 includes a rotating shaft 21 rotatably supported by a bearing BR attached to the motor case CA, a rotor body 22 fixed to the rotating shaft 21, and a rotor body facing the core 15 of the stator 10. And a permanent magnet 23 attached to 22. Although not shown, an insulator is interposed between the core 15 and the coil 13.
In the present specification, as shown in FIG. 2, the direction parallel to the rotation shaft 21 (motor rotation shaft) is defined as the axial direction z, and the radial direction of the planes orthogonal to the axial direction z is defined as the radial direction r. Let the circumferential direction be the circumferential direction θ. The motor MO of the present embodiment is an axial motor in which the stator 10 and the core 20 (specifically, the core 15 of the stator 10 and the permanent magnet 23 of the rotor 20) face each other in the axial direction z. .

  FIG. 2 is an enlarged perspective view showing a part of the core 15. In the figure, illustration of the coil is omitted. FIG. 3 is a cross-sectional view of the stator 10 on the z-θ plane. As shown in FIGS. 2 and 3, the yoke portion 11 is a flat ring member, and includes a plurality of tapered fitting holes 11 a. The teeth portion 12 includes a main body portion 12a, a flange portion 12b provided at the tip of the main body portion 12a, and a tapered base portion 12c. And the base 12c of the teeth part 12 is fastened by the cold fitting to the fitting hole 11a of the yoke part 11 in the strong fitting state.

The yoke portion 11 and the teeth portion 12 of the core 10 of the present embodiment are formed by compression molding magnetic powder having an insulating film. However, a large number of silicon steel plates may be laminated with a resin insulating layer interposed therebetween.
The dimension of the tooth part 12 in the axial direction z is about 20 mm, the diameter of the yoke part 11 and the rotor body 22 is about 100 mm to 150 mm, and the dimension of the motor case CA in the axial direction z is about 40 mm. That is, it can be seen that the motor MO of the present embodiment is a thin axial motor.

4A to 4C are cross-sectional views on the z-θ plane showing the assembly process of the stator according to the embodiment.
First, in the step shown in FIG. 4A, the yoke portion 1 is maintained at room temperature, and the teeth portion 12 is maintained at room temperature or lower, for example, −195 ° C. to −160 ° C., in a state of being reduced from the final dimension. To do. At this time, in the present embodiment, the coil 13 is wound around the body portion 12 a of the tooth portion 12. However, you may wind the coil 13 around the main-body part 12a of the teeth part 12 after the process shown in FIG.4 (c) mentioned later.
At this time, the yoke portion 11 may be heated in a temperature range (eg, 500 ° C. or less, preferably 200 ° C. or less) in which the magnetic performance is not deteriorated.

  Next, in the step shown in FIG. 4B, the base portion 12c of the tooth portion 12 is inserted into the fitting hole 11a of the yoke portion 11, and is stopped at a position where both are in contact with each other. At this time, press-fitting may be performed as long as the pressure magnetic material of the teeth portion 12 and the yoke portion 11 is not damaged.

  Next, the teeth part 12 is returned to room temperature by the process shown in FIG.4 (c). Thereby, the base portion 12c of the tooth portion 12 is gradually fastened to the fitting hole 11a of the yoke portion 11, and finally fastened in a strong fitting state, and the stator 10 is assembled. Since the base portion 12c of the tooth portion 12 expands slowly according to the temperature change, no large impact force or local stress is applied to the tooth portion 12 or the yoke portion 11 in the above-described process.

According to the present embodiment, the core 15 is divided into the tooth portion 12 and the yoke portion 10, so that the core is divided into parts so that the structure can be easily formed, thereby facilitating manufacture. And when assembling the teeth part 12 and the yoke part 11, since the base part 12c of the teeth part 12 is fastened to the fitting hole 11a of the yoke part 11 by a cold fitting in a strong fitting state, the base part 12c and the fitting hole 11a are in strong and uniform contact with each other under a uniform stress. Therefore, the magnetic flow passing through the core 15 can be efficiently used. That is, since the flow of magnetic flux is not hindered by the adhesive or the gap, a large amount of magnetic flux can be generated by the core 15. Moreover, at the time of assembling, since the assembly is performed without applying impact force or local stress to the teeth portion 12 and the yoke portion 11 by using the cold fitting, the core 15 having high reliability can be obtained.
By using such a stator 10, a highly reliable motor MO (see FIG. 1) with high power efficiency can be obtained.

  Further, as shown in FIG. 3, since the base portion 12c of the tooth portion 12 and the fitting hole 11a of the yoke portion 11 are formed in a taper shape, depending on the relative position of the base portion 12c to the yoke portion 11 in the axial direction z. The tightening margin can be adjusted, and the strength of fitting can be controlled within an appropriate range. It should be noted that the variation range Rg of the relative position of the base portion 12c in the axial direction z with respect to the yoke portion 11 is preferably suppressed to about ± 0.1 mm in order to reliably maintain the performance of the core 15.

  Even if the base portion 12c of the teeth portion 12 and the fitting hole 11a of the yoke portion 11 are straight, the base portion 12c of the teeth portion 12 is strongly fitted into the fitting hole 11a of the yoke portion 11 by cold fitting. It is possible to obtain a high-performance and highly reliable core and stator while facilitating manufacture.

  In particular, in the case of an axial motor, a dust magnetic material is more suitable as a material for the core 15 than a laminated steel plate because of the shape of the flange portion 12b of the tooth portion 12 and the like. However, the strength of the dust magnetic material is inferior to that of the laminated steel plate. Therefore, when the teeth portion is press-fitted into the fitting hole of the yoke portion, the possibility of breakage increases. Therefore, by using a dust magnetic material as the core of the present invention, it is possible to reduce the risk of breakage and improve reliability while adopting a structure suitable for an axial motor.

(Modification 1)
FIG. 5 is a cross-sectional view on the z-θ plane of the stator 10 according to the first modification of the embodiment. Also in this modified example, the base portion 12c of the tooth portion 12 and the fitting hole 11a of the yoke portion 11 are provided in a tapered shape and are strongly fitted by cold fitting, but the fitting hole 11a of the yoke portion 11 is It is a hole with a bottom instead of a through hole. And the front end surface of the base part 12c of the teeth part 12 and the bottom wall part 11b of the fitting hole 11 of the yoke part 11 are in phase contact. In this modification, when the thickness of the yoke portion 11 is 5 mm to 10 mm, the thickness of the bottom wall portion 11b may be, for example, about 1.5 mm to 2 mm.

Also according to this modification, a high-performance and high-reliability core can be obtained while facilitating manufacturing, as in the embodiment. Further, the fitting hole 11a is a bottomed hole, and the tip surface of the base portion 12c of the tooth portion 12 and the bottom wall portion 11b of the fitting hole 11 of the yoke portion 11 are brought into phase contact with each other, whereby the tooth portion 12 is axially Although the adjustment range of the tightening allowance depending on the position is narrowed, the axial position of the tooth portion 12 with respect to the yoke portion 11 is constant, so that the performance variation of the core 15 can be suppressed.
When it is desired to secure a sufficient adjustment range of the tightening allowance depending on the axial position of the tooth portion 12, a gap may be provided between the base portion 12c and the bottom wall portion 11b.

(Modification 2)
FIG. 6 is an enlarged plan view illustrating a part of the yoke portion 11 according to the second modification of the embodiment.
In this modification, the fitting hole 11a of the yoke part 11 (and the base part 12c of the teeth part 12) has a straight shape in the axial direction z and has a taper in the radial direction r.

  And when fitting the base 12c of the teeth part 12 to the fitting hole 11a of the yoke part 11, like the embodiment, the teeth part 12 is cooled, and the base 12c is inserted into the fitting hole 11a. After the insertion, the tooth portion 12 is moved in the radial direction r, held in a state where both are in contact, and returned to room temperature. And the base 12c is fastened in the strong fitting state by the fitting hole 11a. At this time, as shown in FIG. 6, in the radial direction r between the base portion 12c of a certain tooth portion 12 and the fitting hole 11a, gaps S11 and S12 are generated at both ends, and the base portion 12c of the other tooth portion 12 is fitted. In the radial direction r with respect to the hole 11a, gaps S21 and S22 occur at both ends, and the range of the variation may be controlled in the same manner as in the embodiment. At this time, the axial position of the tooth portion 12 with respect to the yoke portion 11 can be made constant.

  According to this modification, as in the embodiment, the yoke portion and the tooth portion can be assembled without applying impact force or local stress to the yoke portion 11 or the tooth portion 12. Further, a sufficient adjustment range of the tightening allowance depending on the position of the tooth portion 12 in the radial direction r can be secured. Therefore, the same effect as the embodiment can be exhibited. In addition, if the axial position of the tooth portion 12 with respect to the yoke portion 11 is made constant, variations in core performance can be further suppressed.

  In particular, in the second modification example, as in the first modification example, the fitting hole 11a is used as a bottomed hole, and the tip surface of the base portion 12c of the tooth portion 12 and the bottom wall portion 11b of the fitting hole 11a of the yoke portion 11 are combined. You may make it contact. In that case, since the axial position of the tooth portion 12 with respect to the yoke portion 11 is reliably constant, variation in performance can be suppressed, and the tightening margin can be adjusted by the position of the tooth portion 12 in the radial direction r. A sufficient range can be secured.

(Other embodiments)
In the above embodiment and its modifications, the yoke portion 11 is a flat ring-shaped member. However, the yoke portion 11 is also divided in the same manner as the tooth portion 12, and each tooth portion 12 and the yoke portion 11 are individually assembled. After that, the yoke portions 11 may be connected in a ring shape.

  In the above-described embodiment and its modifications, the example in which the core 15, the stator 10, and the motor MO of the present invention are applied to the axial motor has been described. However, the above-described embodiment can also be realized by applying each invention to a radial motor. And almost the same effect as each modification can be acquired. However, in the axial motor, because of the structure of the tooth portion 12, a dust magnetic material is used, and the tooth portion 12 and the yoke portion 11 are often individually formed. Therefore, the present invention is applied to the core and stator of the axial motor. By applying, a particularly remarkable effect can be exhibited.

  The structure of the embodiment of the present invention disclosed above is merely an example, and the scope of the present invention is not limited to the scope of these descriptions. The scope of the present invention is indicated by the description of the scope of claims, and further includes meanings equivalent to the description of the scope of claims and all modifications within the scope.

  The core, stator and motor of the present invention can be used for motors and generators disposed in industrial motors, hybrid vehicles, electric vehicles, fuel cell vehicles, robots and the like.

It is sectional drawing which shows the schematic structure of the axial motor MO in embodiment. It is a perspective view which expands and shows a part of core in embodiment. It is sectional drawing in the z-theta plane of the stator in embodiment. (A)-(c) is sectional drawing in the z-theta plane which shows the assembly process of a yoke part and a teeth part. It is sectional drawing in the z-theta plane of the stator which concerns on the modification 1 of embodiment. It is a top view which expands and shows a part of yoke part which concerns on the modification 2 of embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Stator 11 Yoke part 11a Fitting hole 11b Bottom wall part 12 Tees part 12a Main body part 12b Gutter part 12c Base part 13 Coil 15 Core 20 Rotor 21 Rotating shaft 22 Rotor main body 23 Permanent magnet BR Bearing CA Motor case MO motor

Claims (9)

A yoke portion having a fitting hole;
A teeth portion having a base portion engaged with the fitting hole;
A stator core formed by assembling
A stator core, wherein a base portion of the tooth portion is fastened to a fitting hole of the yoke portion by cold fitting. A yoke portion having a fitting hole;
A teeth portion having a base portion engaged with the fitting hole;
A stator core formed by assembling
The fitting hole and the base are a stator core having a taper in the motor rotation axis direction. The stator core according to claim 1 or 2,
The fitting hole and the base have a stator core having a taper in a radial direction. In the stator core according to any one of claims 1 to 3,
The stator hole is a stator core having a bottomed hole. In the stator core according to any one of claims 1 to 4,
The yoke portion is a stator core having a ring-shaped integrated structure. A stator core according to any one of claims 1 to 5,
A coil wound around the teeth portion;
Comprising a stator. A stator according to claim 6;
A rotor disposed opposite the stator;
Equipped with a motor. The motor according to claim 7, wherein
The rotor is a motor that faces the stator in a motor rotation axis direction. A method for assembling a stator having a core divided into a yoke part and a tooth part,
(A) inserting the base portion into the fitting hole of the yoke portion in a state where the teeth portion is cooled;
A step (b) of fastening the base portion to each fitting hole of the yoke portion by returning the teeth portion to room temperature;
Assembling method of stator including

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