JP2003264947A - Permanent magnet motor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce vibration and noise by lessening the rate of change of a magnetic flux accompanying rotation, and also to contrive rise of lamination factor in groove of stator winding and cost reduction. <P>SOLUTION: In a permanent magnet motor where an armature is a stator 10 and a field is a rotor 3, the iron core of the stator 10 is made as divided into the iron core of a cylindrical yoke 11, and the iron core of a tooth part 12 is provided inside that yoke 11. The tooth 12 has a specified number of teeth 12 at equal intervals in circumferential direction, and both ends 12b and 12c of the end on rotor side of each tooth 12a are extended each in circumferential direction. Between adjacent teeth 12a, the extended ends 12b and 12c are coupled and integrated with each other by a coupling 12d. At the inside periphery of the yoke 11, a groove 11a is made in opposition to each groove 12a, and each tooth 12a of the tooth 12, where winding 13 is applied to a bobbin 14 and they are united together, is set in each groove. Then the yoke side of each groove 12 is press-fitted in the groove 11a of the yoke 11 from the direction of a rotary shaft. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inner rotor type permanent magnet electric motor (for example, a brushless DC motor) used for home electric appliances such as an air conditioner, and more specifically, it is fixed so as to reduce torque fluctuation. The present invention relates to a permanent magnet electric motor that has been devised on a child.

[0002]

2. Description of the Related Art A permanent magnet electric motor has an IPM type rotor (field) arranged inside a stator (armature), and an example of a three-phase four-pole motor is shown in FIG.

The stator 1 of the permanent magnet motor is a cylindrical shape having a predetermined thickness, and the inner periphery of the stator 1 has teeth 1a extending toward the center.
3n (n; positive integer, n = 2 in this example) are formed at equal intervals in the circumferential direction, and the concentrated winding 2 is formed on each tooth 1a.
Has been applied. In addition, an end portion extending in the circumferential direction is provided on the rotor 3 side of each tooth 1a.

In this example, the rotor 3 disposed inside the stator 1 has a pair of first permanent magnets (for example, ferrite magnets) 4a and 4b and a second permanent magnet (for example, rare earth magnet) 5 in the circumferential direction. Embedded at equal intervals to form 4n poles.

The first permanent magnets 4a and 4b are rectangular in cross section, and four poles thereof are embedded from the outer circumference toward the rotary shaft 6 side, and the second permanent magnet 5 is rectangular in cross section.
It is embedded between the end portions on the side of the rotating shaft 3 between a and 4b.

That is, the first permanent magnets 4a and 4b are embedded parallel to the q-axis, and the second permanent magnet 5 is embedded so that the long side of the rectangular section is perpendicular to the d-axis. In addition,
A flux barrier 7 is provided between the first permanent magnets 4a and 4b and the second permanent magnet 5 to prevent leakage of magnetic flux and short circuit.
a and 7b are provided respectively.

The first permanent magnets 4a and 4b are arranged such that the long side of the rectangular section has a pole and the insides thereof have the same pole, and the second permanent magnet 5 has the long side opposite to the rotary shaft 6. Is a pole, and the magnetic pole of the rotor 3 is formed. Also, the first
The poles of the permanent magnets 4a, 4b and the second permanent magnet 5 are different from the poles of the other adjacent first permanent magnets 4a, 4b and the second permanent magnet 5 to form a four-pole magnetic pole on the rotor 3. is doing.

According to the permanent magnet motor having this structure, the stator 1 has the same inner diameter and has a uniform air gap, and the d axis of the rotor 3 is made of a magnetic steel plate for generating reluctance torque. Will have magnetic poles.

Further, due to the interaction between the rotating magnetic field of the stator 1 and the magnetic fields of the permanent magnets 4a, 4b, 5 of the rotor 3, a magnet torque which is a rotating force is generated. In addition, in the inner region (electromagnetic steel plate) of the first permanent magnets 4a and 4b and the second permanent magnet 5, the magnetic flux path (magnetic path) of the magnetic flux from the stator 1 from one q axis to the other q axis. Is ensured and the path of the magnetic flux from one d-axis to the other d-axis is blocked especially by the permanent magnet 5, so that the d-axis and q-axis inductance difference is large and reluctance torque is generated. Therefore, the total torque including the magnet torque and the reluctance torque becomes large, and it is possible to realize a highly efficient motor.

[0010]

However, in the above-mentioned conventional permanent magnet motor, the iron core (core) of the stator 1 is formed with the open groove, that is, the tooth 1a is formed on the inner circumference of the core, and the inner winding is formed. Since the winding 2 is applied to the tooth 1a through the groove by the winding method, the torque fluctuation with respect to the rotation angle becomes large, the vibration and noise increase, and the space in which the needle reciprocates in the groove becomes large. It is necessary, and the groove space factor of the winding is reduced even if it is returned, and there is a problem in that the winding resistance increases and the efficiency decreases accordingly.

For example, when the rotor 3 rotates counterclockwise by a predetermined angle, torque is generated as shown in FIG. Note that the positional relationship between the rotor 3 and the teeth 1a of the stator 1 is 0 degree when it is at the position shown in FIG.

When the extreme portion a of the rotor 3 approaches the end portion b of the tooth 1a of the stator 1, the torque reaches the peak A, and the extreme portion c of the rotor 3 approaches the end portion d of the tooth 1a. sometimes,
The torque reaches peak B.

When the permanent magnet motor is a brushless DC motor, the energization pattern of the armature winding is switched every 60 electrical degrees, so that the peak A and B are used to keep the torque as large as possible. Preferably.

However, the larger the peak torques A and B, the larger the torque ripple. That is, since the rate of change of the magnetic flux due to the rotation is the maximum near the peak, the torque fluctuation is large, and thus the vibration and the noise are large.

The present invention has been made to solve the above-mentioned problems, and its purpose is to reduce the rate of change of magnetic flux due to rotation to reduce vibration and noise, and to reduce the stator winding. An object of the present invention is to provide a permanent magnet electric motor capable of improving the groove space factor and reducing the cost.

[0016]

In order to achieve the above object, the present invention is a permanent magnet comprising an armature as a stator, a field as a rotor, and the rotor arranged inside the stator. In the magnet electric motor, the iron core of the stator includes an iron core of a cylindrical yoke portion and an iron core of a tooth portion which are formed separately, and the tooth portion has 2n pieces (n; a positive integer of 2 or more). ) Teeth are provided at equal intervals in the circumferential direction, the rotor side of each of the teeth is connected to each other by end portions extending in the circumferential direction, and each of the teeth is provided with a winding wire. It is characterized in that the tooth portion is press-fitted inside the yoke portion in the axial direction thereof.

In this case, a recessed groove is formed inside the yoke portion so as to fit with the yoke-side end portion of each tooth, and the yoke-side end portion of the tooth is press-fitted into each recessed groove to prevent misalignment. It is possible to reliably join the yoke portion and the tooth portion without causing them.

A dovetail joint made of a combination of dovetail groove and dovetail, which is often used in woodworking, or a hook joint made of a combination of a convex portion and a concave groove with a wide tip is used at the joint portion between the yoke portion and the tooth portion. It is preferably applied.

The thickness (radial thickness) k of the connecting portion connecting the extending portions of the rotor side ends of the teeth of the tooth portion should be smaller than the thickness t of the extending portion. Is preferred.
In addition, the end of each tooth of the teeth on the rotor side is extended in the circumferential direction, the thickness (thickness in the radial direction) is gradually reduced, and the midpoint between the adjacent teeth is May be thinnest. According to this, since the thickness of the connecting portion or the midpoint of the adjacent tooth is thinner than other portions, more magnetic flux flows to the tooth side, and the magnetic flux at that location is close to saturation, but the average torque is There is no leakage magnetic flux that would be reduced.

The tooth winding may be formed by directly winding a concentrated winding by electrically insulating each tooth, or by using an electrically insulating material that can be attached to each tooth from its yoke end. A bobbin (winding frame) with concentrated winding may be used. In any case, since the winding is applied to the tooth portion in a state where it is separated from the yoke portion, and the tooth portion having the winding is joined to the yoke portion, the groove space factor of the stator winding is reduced. It can be made large and cost can be reduced.

According to a preferred embodiment of the present invention, in the field magnet, permanent magnets having a rectangular cross section are embedded at equal intervals in the circumferential direction of the rotor by a predetermined number of poles, and the long sides of the rectangular cross section of the permanent magnet are embedded. Magnetic poles are formed on the rotor by arranging them at right angles to the d-axis and on the rotary shaft side, and the outer peripheral side of the rotor is at both ends (short side end parts) of the rectangular section of these permanent magnets. A flux barrier extending in the direction and parallel to the q-axis is formed. These flux barriers prevent magnetic flux short circuit and leakage of the permanent magnet. Further, if a rare earth magnet is used as the material of the permanent magnet due to its shape and position, the magnet torque will be large to some extent, and the amount used will not be so large.

According to another aspect, in the field magnet, permanent magnets having a rectangular cross section are embedded at equal intervals in the circumferential direction of the rotor by a predetermined number of poles, and the long sides of the rectangular cross section of the permanent magnet are embedded. Magnetic poles are formed on the rotor by arranging them at right angles to the d-axis and on the outer peripheral side of the rotor. The permanent magnet has the above-mentioned rotation at both ends (short side end) of the rectangular section. A flux barrier is formed by cutting out the vicinity of the q-axis on the outer periphery of the child. This also prevents magnetic flux short circuit and leakage of the permanent magnet. Further, even if an inexpensive ferrite magnet is used as the material of the permanent magnet due to its shape and position, the magnet torque is large to some extent and the efficiency can be improved.

According to still another aspect, the field is 1
A permanent magnet with an arcuate cross-section having a layered or multi-layered structure is embedded in the center of the d-axis by the number of poles, and the apex of the arcuate cross-section is oriented toward the rotation axis and both ends of the arcuate cross-section are oriented toward the q-axis By doing so, magnetic poles are formed on the rotor. As a result, the reluctance torque is large, the total torque combined with the magnet torque is large, and the efficiency can be improved.

The yoke portion, the tooth portion, and the iron core of the rotor may be obtained by punching the same material of an electromagnetic steel plate or a cold-rolled steel plate and automatically laminating and caulking them. Further, when the iron cores of the yoke portion and the tooth portion are punched out and the tooth portion is wound, when the yoke portion and the tooth portion are joined,
It is preferable that the iron core punched out first is aligned with the iron core punched later and the position on the die is press-fitted in the same direction as when punching to obtain the stator.

When the tooth portion is press-fitted into the yoke portion, it is preferable to heat the yoke portion and then press-fit the tooth portion to obtain the stator. By adopting these techniques, the existing automatic laminating method can be used, and the teeth can be press-fitted and joined to the yoke with high accuracy.

[0026]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail with reference to FIGS. Note that, in FIG. 1, the same reference numerals are attached to the components that may be the same as or considered to be the same as those of the conventional example described in FIG.

The permanent magnet electric motor of the present invention is an inner rotor type in which the armature is the stator and the field is the rotor, and the yoke portion of the stator and the tooth portion having a plurality of teeth are formed in advance by division. As for the teeth, the rotor-side ends of the adjacent teeth are connected to be integrated. The teeth are joined to the yoke while concentrated winding is applied to each tooth, and the peak torque value at the point where the end of the tooth and the magnetic pole of the rotor meet is lowered to reduce the torque change due to rotation. Lower the rate,
Also, the winding space factor is increased.

Therefore, as shown in FIG. 1 and FIG.
The stator 10 included in the permanent magnet electric motor of the present invention includes a cylindrical yoke portion 11 having a predetermined thickness, tooth portions 12 joined to the inner peripheral side of the yoke portion 11, and windings applied to the tooth portions 12. Line 13
It has and.

The tooth portion 12 has 3n (n; a positive integer of 2 or more, n = 2 in this example) teeth 12a in the same manner as the stator 1 described in FIG. The circumferential ends 12b and 12c of the rotor 12 on the side of the rotor 3 are connected to adjacent teeth 12a.
The end portions 12b and 12c are connected by a connecting portion (bridge) 12d to be integrated. Since the rotor 3 has permanent magnets forming 2n magnetic poles and may have the structure of the conventional example of FIG. 13, the description thereof will be omitted.

The stator 10 will be described in detail. As is clear from FIG. 2, the teeth 12a are formed on the inner peripheral side of the yoke portion 11.
A concave groove 11a fitted to the outer peripheral side is formed so as to face each tooth 12a.

In this embodiment, the tooth portion 12 is provided with six teeth 12a. However, between the end portions 12b and 12c extending on both sides in the circumferential direction on the rotor 3 side of each tooth 12a. They are integrally connected via the connecting portion 12d. Also, tooth 1
2a has a rectangular cross section, and each tooth 12a is provided with a concentrated winding 13.

The teeth 12 are joined to the yoke 11 by press-fitting the teeth 12a into the concave grooves 11a of the yoke 11 along the axial direction of the stator 10. The radial length of the tooth 12a is set in consideration of the air gap.
It is preferable to increase the length by the depth.

The ends 12b and 12c on both sides of each tooth 12a are made thinner toward the tip, and the connecting portion 12d has a thickness (radial thickness) at the tip t (for example, 1.5 mm to 2 m).
m), the thickness k in the radial direction is made smaller than the thickness t.

A winding 13 is provided on each tooth 12a. For example, the winding (magnet wire) 13 is concentratedly wound on a bobbin (winding frame) 14 made of an electrically insulating material, and the bobbin 14 is moved to the tooth 12a.
Pay to. Alternatively, each tooth 12a may be provided with an insulating film, and the winding may be directly provided on the insulating film.

In this permanent magnet motor, the stator 10
The bobbin 14 having the winding 13 is housed in the tooth 12a, and the tooth portion 12 having the winding 13 is press-fitted into the groove 11a of the yoke portion 11 from the axial direction of the rotary shaft 6 so that the yoke portion 11 and the tooth portion 12 Are obtained by joining (see FIG. 3).

By energizing the winding 13, for example, switching the three-phase energization, a rotating magnetic field is generated in the stator 10, and this rotating magnetic field and the permanent magnet 4 of the rotor 3 are generated.
Magnet torque is generated by the interaction with the magnetic fields of a, 4b and 5, and reluctance torque similar to the conventional one is generated, and these rotate the rotor 3.

At this time, when the rotor 3 is rotating counterclockwise, as shown in the conventional example of FIG. 13, when the extreme part of the rotor 3 approaches the tip of the end 12c of the tooth 12a, the magnetic flux Are concentrated on the tip, but this magnetic flux is applied to the connecting portion 12d.
, The magnetic flux concentration at the tip portion is relaxed and the magnetic flux is dispersed.

When the rotor 3 is rotating in the clockwise direction, when the extreme part of the rotor 3 approaches the tip of the end 12b of the tooth 12, the magnetic flux concentration at the tip is relaxed. . In addition, the thickness k of the connecting portion 12d is set to the end portions 12b, 12b.
Since it is thinner than the thickness t, the magnetic flux is close to the saturated state, but no leakage magnetic flux that reduces the average torque is generated.

As described above, since the magnetic flux concentration at the end 12c or the end 12b of the tooth 12 is alleviated, the values of the torque peaks A and B shown in FIG.
The rate of change of magnetic flux with respect to the rotation angle decreases. Therefore, the torque ripple is reduced and the torque fluctuation is reduced (vibration,
Noise reduction).

Further, since the yoke portion 11 and the tooth portion 12 are formed separately, it is necessary to consider the passing space of the needle for winding the winding wire 13 as in the conventional example. Disappear. Therefore, the groove space factor of the winding 13 can be increased, the winding resistance can be reduced, and high efficiency can be achieved.

In manufacturing, a method of punching the same material such as an electromagnetic steel plate or a cold rolled steel plate and automatically laminating is adopted, and the yoke portion 11 and the tooth portion 12 of the armature core are
And the rotor 3 of the field core is punched out. The punched electromagnetic steel plates and the like are automatically laminated, and at the time of lamination, the caulked portions 11b, 12e, 8a, 8b are formed and caulked, and the permanent magnets 4a, 4b, 5 are embedded in the rotor 3.

When punching out the yoke portion 11 and the tooth portion 12, the concave shape of the groove 11a of the yoke portion 11 and the tooth portion 12 are formed.
With the convex shape of, the rotation stop and positioning functions are demonstrated,
High accuracy of core manufacturing can be achieved.

The bobbin 14 having the winding 13 is attached to the tooth 1.
2a, after press-fitting this into the yoke portion 11 and joining, as shown in FIG. 4, the surfaces where the burrs appear in the opposite direction when punched are aligned and the teeth are attached to the yoke portion 11. The part 12 is fitted.

In this case, the iron core punched first is aligned with the iron core punched afterwards on the punching die, and the iron core is press-fitted in the same direction as in the punching to assemble. Also, the tooth portion 12
When press-fitting into the yoke portion 11, it is preferable to heat the yoke portion 11 side, that is, to expand the yoke portion 11 and press-fit the tooth portion 12. As a result, the tooth portion 12 is joined to the yoke portion 11, and the integral stator 10 is obtained, and furthermore, it is easily assembled.

FIG. 5 is a schematic partially enlarged view of a stator 20 according to another embodiment. In the figure, the same parts as those in FIG. This stator 20
Has a tooth portion 21 joined to the inner peripheral side of the yoke portion 11 similarly to the tooth portion 12 of FIG. 1, but both ends of each tooth 21a constituting the tooth portion 21 on the rotor side in the circumferential direction. Parts 21a, 2
1b is hung on the tip and gradually thinned, and adjacent teeth 21a
It becomes the thinnest shape at the midpoint of.

In the manufacture of this stator 20, the iron core of the tooth portion 21 is obtained by punching out an electromagnetic steel plate or a cold rolled steel sheet as in the above embodiment, but according to this embodiment, the tooth portion 12 of the above embodiment is obtained. Since the tooth portion 21 is not complicated as compared with the shape of, the manufacturing accuracy of the tooth portion 21 can be improved.

As in the above embodiment, the tooth portion 21 is provided with the winding 13, and the bobbin 14 is provided with the winding 13 and housed in each tooth 21, and the rotor 3 is used as the stator 20. Further, the manufacturing of the stator 20 and the rotor 3 may be the same as the description in the above-mentioned embodiment, and therefore the description thereof is omitted.

6 to 9 are schematic partially enlarged views showing modifications of the stator of each of the above-described embodiments. These modified examples are different in the joining method between the yoke portion and the tooth portion of the stator, and the joining method using the joint shown in FIG. 6 or the hook joint shown in FIG. 7, which uses a joint often used in woodworking work,
A bonding method using another shape shown in FIGS. 8 and 9 has been described.

The stator 30 shown in FIG. 6 includes a yoke portion 31.
And a joint is used at the joint between the tooth portion 32 and the tooth portion 32. As in the above-described embodiment, the tooth portion 32 includes the tooth 32a of the main body and the end portion 32 extending in the circumferential direction at the rotor side end portion of each tooth 32a.
b, 32c, and a connecting portion 32d for connecting the end portions 32b, 32c of the adjacent teeth 32a so as to integrally form the tooth portion 32 in a circular shape.

A dovetail-shaped dovetail 32e is provided at the end of the tooth 32a on the yoke side, and a dovetail groove 31a fitted to the dovetail 32e is formed on the inner peripheral side of the yoke part 31 so as to face each tooth 32a. ing. Further, the main body of the tooth 32a has a rectangular cross section as in the above embodiment, and a part of the yoke side end portion of this main body is set to bite into the yoke portion 31. Therefore, the yoke portion 31 is provided with a groove of a concave portion that fits in the rectangular shape of the cross section, and the groove 3 is provided on the bottom side of the concave portion.
1e is formed.

In the stator 40 shown in FIG. 7, a hook joint is used at the connecting portion between the yoke portion 41 and the tooth portion 42. Tooth 4
2 is the tooth 42a of the main body and the end portions 42b extending in the circumferential direction at the rotor side end portion of each tooth 42a, as in the above-described embodiment.
42c and a connecting portion 42 that joins the end portions 42b and 42c of the adjacent teeth 42a in order to integrally form the tooth portion 42 into a circular shape.
It consists of d and.

A convex portion 42e having a wide tip is provided at the end of the tooth 42a on the yoke side, and the tooth 4 is provided on the inner peripheral side of the yoke portion 41.
A concave groove 41a that fits into a part of 2a and the convex portion 42e is formed facing each tooth 42a. The convex portion 42
Although the left and right ends of the shape of a are rounded and the ends thereof are linear, the shape of a may be rectangular. In this case, a stepwise concave portion having a wide bottom is formed on the inner peripheral side of the yoke portion 41.

The stator 50 shown in FIG. 8 includes a yoke portion 51.
A method having a shape similar to the joint shape of the dovetail joint shown in FIG. 6 is used for the joint between the tooth portion 52 and the tooth portion 52. The tooth portion 52 is similar to the above-described embodiment in that the tooth 52 a of the main body and each tooth 52 a
end portions 52b, 52 extending in the circumferential direction at the rotor side end portion of a
c, and a connecting portion 52d that connects adjacent teeth 52a in a circular shape in order to integrally form the tooth portion 52 in a circular shape.

An elliptical elliptical convex portion 52e is provided at the yoke side end of the tooth 52a, and a constriction is formed between the end portion and the elliptical convex portion. The yoke portion 51 has teeth 52a
Groove 51a that fits into a part of the groove and the elliptical convex portion 52e
Are formed to face each tooth 52a.

The stator 60 shown in FIG. 9 includes a yoke portion 61.
For the joint between the tooth portion 62 and the tooth portion 62, a method using a joint shape of the hook joint shown in FIG.
The tooth portion 62 is the tooth 62a of the main body as in the above-described embodiment.
And each tooth portion 62 is similar to the first embodiment in that the tooth 6 of the main body is
2a, the end portions 62b and 62c extending along the inner circumference at the rotor side end portion of the tooth 62a, and the connecting portion 62d that joins the adjacent tooth 62a in order to make the tooth portion 62 into a circular shape. Become.

A trapezoidal trapezoidal convex portion 62e is provided at an end of the tooth 62a on the yoke side, and a concave groove 61a fitted to a part of the tooth 62a and the trapezoidal convex portion 62e is formed in each tooth 62a. It is formed facing each other.

In this modified example, the joint portion is shaped so that it can be easily pulled away in the direction parallel to the paper surface, but the integrated tooth portion 62 is used.
As in the above embodiment, the yoke portion 61 is fitted in the axial direction of the rotary shaft 6 to connect the yoke portion 61 and the tooth portion 62, so that the yoke portion 61 and the tooth portion 62 are not separated from each other as in the modified examples shown in FIGS. It does not have to be a shape.

The modified examples shown in FIGS. 6 to 9 may be applied to each of the above-described embodiments, and the tooth portions 32, 42, 52, 62 of each modified example are similar to the above-described embodiments. Winding 13 is applied to each of the teeth, or the winding 13 is applied to the bobbin 14 and housed in each tooth 32a, 42a, 52a, 62a, and the rotor 3 is used for each stator 30, 40, 50, 60. . Further, the manufacturing of each of the stators 30, 40, 50, 60 may be the same as that described in the first embodiment, and therefore the description thereof will be omitted.

By the way, the above-mentioned respective embodiments and FIG.
The rotor applied to each modified example of FIG. 9 to FIG.
The rotors 70, 80, 90 shown in FIGS. 0 to 12 may be applied. The rotor 70 shown in FIG. 10 includes a permanent magnet (for example, a rare earth magnet) 71 having a rectangular cross section, which serves as a field, and has 2n (n).
= 2) the rotors 70 are embedded at equal intervals in the circumferential direction of the rotor 70.

Each of the permanent magnets 71 has a long side of the rectangular cross section facing the rotating shaft 6 at a right angle to the d axis and is arranged closer to the rotating shaft 6 than the outer peripheral side to form magnetic poles. On both end sides of the permanent magnet 71 (shorter sides of the rectangular section), the flux barriers 7 extending linearly toward the outer periphery and parallel to the q-axis.
2a and 72b are formed.

The adjacent permanent magnets 71, 71 have different polarities, and the opposing permanent magnets 71, 71 have the same polarities.
According to the rotor 70, since the amount of permanent magnet 21 used is smaller than that of the rotor 3 of FIG. 1, the magneto torque is smaller than that of the previous embodiment, but effective generation of relatance torque can be expected. In addition, cost reduction can be realized.

The rotor 80 shown in FIG. 11 has permanent magnets 81 of 2n (n = 2), which are rectangular in cross section and serve as field magnets, embedded at equal intervals in the circumferential direction of the rotor 80. Is arranged so that the long side of the rectangular cross section faces the rotating shaft 6 at a right angle to the d-axis and is located closer to the outer peripheral side than the rotating shaft 6 to form magnetic poles. Is formed by cutting out the outer periphery of the rotor 80 to form the flux barrier 32.

The notch shape of the flux barrier 82 is
It is 1/4 circle parallel to the short side of the rectangular section of the adjacent permanent magnet 81. The adjacent permanent magnets 81, 81 have different polarities, and the opposing permanent magnets 81, 81 have the same polarities.

According to the rotor 80, for example, a rare earth magnet or a ferrite magnet is used as the material of the permanent magnet 81, but since the permanent magnet 81 is arranged near the outer peripheral side of the rotor 80, the rotor 70. Since the amount of magnet used can be larger than in the case of No. 3, it has the same effect as the rotor 3 of FIG. You can
Therefore, cost reduction can be realized.

A rotor 90 shown in FIG. 12 has a permanent magnet 91 having a circular arc shape in cross section (thin cross section fan shape) which becomes a field.
Only (n = 2) pieces are embedded in the center of the d-axis. Each of the permanent magnets 91 has magnetic poles formed by arranging the vertices of the arcuate cross section toward the rotating shaft 6 and arranging both ends of the arcuate cross section in the q-axis direction in an inverse arc shape. Adjacent permanent magnets 91, 91 have different polarities, and opposing permanent magnets 91, 91 have the same polarities.

According to the rotor 90, for example, a rare earth magnet or a ferrite magnet is used as the material of the permanent magnet 91, but since the permanent magnet 81 has an arc-shaped cross section, the rotor 3 has substantially the same shape as the rotor 3 of FIG. In addition, since the amount of magnet used can be larger than that of the rotor 70, even if a ferrite magnet is used as in the second modification, the same generation of magnet torque as in the first modification can be achieved. Can be expected,
Therefore, cost reduction can be realized.

Although not shown, in addition to the modification described above, a permanent magnet (one-layer structure) 91 of the rotor 90 shown in FIG.
Instead of this, a field magnet having a multilayer structure of permanent magnets having an arc-shaped cross section may be used. As the field of the rotor, two permanent magnets having a rectangular cross section may be formed into an inverted V shape, and 2n (n = 2) of the pair of permanent magnets may be embedded in the center of the d-axis. .

Further, as the field of the rotor 3, the permanent magnet having a trapezoidal cross section is used as the center of the d-axis so that its upper side faces the rotating shaft 6 side and its bottom side faces the outer peripheral side of the rotor 6, or The permanent magnet having an arc cross section is centered on the d-axis, the outer arc is directed toward the outer peripheral side of the rotor 3, and the inner arc is directed toward the rotary shaft 6 side, or the base of the trapezoidal cross section is the outer peripheral side of the rotor 3. A permanent magnet having a cross-sectional shape along the axis is centered on the d-axis, and each of the permanent magnets is 2n (n
= 2) may be embedded at equal intervals in the circumferential direction of the rotor 3.

As described above, the rotor 3 can be appropriately selected according to the purpose of use of the motor. If the permanent magnet motor according to the present invention is used as, for example, a compressor motor of an air conditioner, the cost of the air conditioner can be reduced and the performance of the air conditioner can be improved (operation efficiency is increased, vibration and noise are decreased). You can

In the embodiment shown in FIG. 1, a rotor 3 having a four-pole structure is used, in which a U-phase, W-phase, V-phase winding 13 is provided on a stator 10 having 6 slots. 9
It is composed of a slot stator and a 6-pole rotor.
It may be applied to a case where the stator is composed of 12 slots and a rotor having 8 poles.

[0071]

As described above, according to the present invention,
In an inner rotor type permanent magnet electric motor that uses an armature as a stator and a field as a rotor, the stator core is composed of a cylindrical yoke core and a tooth core provided inside the yoke core. The tooth part is divided into 2n teeth (n;
2 and more positive integers) at equal intervals in the circumferential direction to extend both ends of the rotor side end of each tooth in the circumferential direction, and to connect the extended ends with adjacent teeth. And
Since winding is applied to each tooth of the integrated tooth portion and this tooth portion is press-fitted and joined to the yoke portion from the direction of the rotation axis, magnetic flux for generating torque is applied to adjacent teeth. It is alleviated at the connecting portion of the rotor side end portion, that is, the rate of change of magnetic flux accompanying rotation is small (torque fluctuation is small), and vibration and noise can be reduced.

Further, since the winding is formed on the tooth portion separated from the yoke portion, the winding space is wide, the groove space factor of the data winding is improved, and the cost can be reduced.

[Brief description of drawings]

FIG. 1 is a schematic structural diagram of a permanent magnet electric motor according to an embodiment of the present invention.

2 is a schematic partial enlarged view of the stator shown in FIG. 1. FIG.

FIG. 3 is a schematic cross-sectional view for explaining a joined state of a yoke portion and a tooth portion of the stator shown in FIG.

4 is a schematic partial view of a stator for explaining a joined state of a yoke portion and a tooth portion shown in FIG.

FIG. 5 is a schematic partial view of a stator of a permanent magnet electric motor according to another embodiment of the present invention.

FIG. 6 is a schematic partial view of a stator showing a first modified example of a joint portion between the yoke portion and the tooth portion.

FIG. 7 is a schematic partial view of a stator showing a second modification of the joint portion between the yoke portion and the tooth portion.

FIG. 8 is a schematic partial view of a stator showing a third modification of the joint portion between the yoke portion and the tooth portion.

FIG. 9 is a schematic partial view of a stator showing a third modified example of the joint portion between the yoke portion and the tooth portion.

FIG. 10 is a schematic structural diagram illustrating an example of a rotor used in the permanent magnet motor of the present invention.

FIG. 11 is a schematic structural diagram illustrating another example of a rotor used in the permanent magnet motor of the present invention.

FIG. 12 is a schematic structural diagram illustrating another example of a rotor used in the permanent magnet electric motor of the present invention.

FIG. 13 is a schematic structural diagram for explaining a conventional permanent magnet electric motor.

14 is a schematic torque graph diagram for explaining characteristics of the permanent magnet electric motor shown in FIG.

[Explanation of symbols]

3,70,80,90 rotor 4a, 4b 1st permanent magnet 5 Second permanent magnet 6 rotation axes 8a, 8b 11b, 12e caulking portion 10, 20, 30, 40, 50, 60 Stator 11 Yoke part 11a concave groove) 12 teeth 12a teeth 12b, 12c ends 12d connection part 13 windings 14 bobbins k Thickness of connecting part t Edge thickness

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) H02K 1/27 H02K 1/27 501K 3/18 3/18 P 21/16 21/16 M (72) Invention Person Yoshifumi Fukuda 1116 Suenaga, Takatsu-ku, Kawasaki-shi, Kanagawa Incorporated Fujitsu General (72) Inventor Satoshi Tsukamoto 1116 Suenaga, Takatsu-ku, Kawasaki-shi, Kanagawa Incorporated (72) Incorporated, Fujitsu Taku Fujioka Kawasaki, Kanagawa 1116 Suenaga, Takatsu-ku, Ltd. Within Fujitsu General Co., Ltd. (72) Inventor Yoichi Tanabe 1116 Suenaga, Takatsu-ku, Kawasaki City, Kanagawa Prefecture F-Term within Fujitsu General Co., Ltd. BB12 CA01 CA05 CB02 CC03 CC17 CC18 CD21 5H621 AA04 BB07 BB10 GA01 GA04 GA16 GB08 HH01 5H622 AA03 CA02 CA05 CA07 CA10 CA13 CB02 CB0 3 CB04 DD01 PP11

Claims (13)

[Claims] 1. A permanent magnet electric motor in which an armature is a stator, a field is a rotor, and the rotor is arranged inside the stator. In the permanent magnet electric motor, the iron core of the stator is formed separately. A cylindrical yoke portion and a tooth portion, each of which has 2n (n; a positive integer of 2 or more) teeth at equal intervals in the circumferential direction. The rotor side of each tooth is connected to each other by an end portion extending in the circumferential direction, and each tooth is provided with a winding wire, and the tooth portion is press-fitted inside the yoke portion from its axial direction. Permanent magnet electric motor characterized by having. 2. The inside of the yoke portion is formed with a concave groove that fits with the yoke side end portion of each tooth, and the yoke side end portion of each tooth is press-fitted into each concave groove. The permanent magnet electric motor according to claim 1. 3. The permanent magnet electric motor according to claim 1, wherein the yoke portion and the tooth portion are integrally joined by a joint. 4. The permanent magnet electric motor according to claim 1, wherein the yoke portion and the tooth portion are integrally joined by a rotary hook joint. 5. The thickness (radial thickness) of a connecting portion that connects end portions of each tooth extending in the circumferential direction from the rotor side is thinner than the thickness of the end portion. Claim 1
The permanent magnet electric motor according to any one of items 1 to 4. 6. The rotor-side end of each tooth extends in the circumferential direction while gradually reducing the thickness (thickness in the radial direction), and the end of the adjacent tooth is The permanent magnet electric motor according to any one of claims 1 to 4, wherein the thickness of the intermediate point is the smallest. 7. The winding of the tooth portion is formed by winding a concentrated winding wire by electrically insulating each tooth, or an electric insulating material that can be attached to each tooth from the end of its yoke portion. The permanent magnet electric motor according to any one of claims 1 to 6, wherein the bobbin (reel) is provided with concentrated windings. 8. The field magnet has permanent magnets of rectangular cross section embedded at equal intervals in the circumferential direction of the rotor by a predetermined number of poles, and the long sides of the rectangular cross sections of the permanent magnets with respect to the d-axis. Magnetic poles are formed on the rotor by arranging them at right angles and arranging them on the axial center side of the rotor. The permanent magnet electric motor according to claim 1, wherein a flux barrier extending in the outer peripheral direction of the child and parallel to the q axis is formed. 9. The field magnet has permanent magnets of rectangular cross section embedded at equal intervals in the circumferential direction of the rotor by a predetermined number of poles, and the long sides of the rectangular cross sections of the permanent magnets with respect to the d-axis. Magnetic poles are formed on the rotor by arranging them at right angles and on the outer peripheral side of the rotor, and the rotor is provided at both ends (short side end) of the rectangular section of each permanent magnet. The permanent magnet electric motor according to claim 1, wherein a flux barrier is formed by cutting out the vicinity of the q-axis on the outer periphery of the flux barrier. 10. The field magnet is formed by embedding a permanent magnet having a one-layer or multi-layer structure and having an arcuate cross-section in the center of the d-axis by a predetermined number of poles, and the vertex of the arcuate cross-section is located on the axial center side of the rotor. The permanent magnet electric motor according to claim 1, wherein the rotor has magnetic poles formed by arranging both ends of the arcuate cross section toward the q-axis side. 11. The yoke, the teeth and the iron core of the rotor are formed by punching out the same material of an electromagnetic steel plate or a cold rolled steel plate and automatically laminating each of them. Permanent magnet electric motor. 12. When the iron cores of the yoke portion and the tooth portion are punched out and the yoke portion and the tooth portion are joined in a state where the tooth portion is wound, the iron core punched out first The press-fitting is performed in the same direction as in the punching by aligning the position on the punching die with the punched iron core.
1. The permanent magnet electric motor according to 1. 13. The permanent magnet electric motor according to claim 12, wherein the tooth portion is press-fitted while the yoke portion is heated.