JPH10112945A - Permanent magnet rotor and manufacturing method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the structure of a permanent magnet rotor of a DC motor which allows magnet torque and reluctance torque to have the same current phase and be maximum and also provide a method for manufacturing the structure. SOLUTION: A rotor 11 comprises a rotor core 12, a shaft press-fit in a shaft hole 14 formed at the center of the rotor core, two permanent magnets 13 located around the shaft, and a tube 15 for preventing the permanent magnets from coming off. The permanent magnets are located at equal intervals on the surface of the rotor core and the rotor core has projecting salient pole sections 16 between the permanent magnets. Each of the salient pole sections is at an electric angle of 45 deg. in the forward rotating direction of the rotor from the center 17b of the magnetic pole.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a permanent magnet rotor for effectively utilizing not only a magnet torque but also a reluctance torque to realize high efficiency of a device and a method of manufacturing the same.

[0002]

2. Description of the Related Art As shown in FIG. 25, a conventional permanent magnet rotor has magnetic poles arranged concentrically around a shaft hole 254 on a rotor core 252 made of a high magnetic permeability material such as iron or laminated electromagnetic steel plates. Several sets of punched holes 255a,
Permanent magnets 253a and 253b are embedded in 255b.

A magnetic flux passing through the magnetic path Pq between the magnetic poles of the rotor is called a q-axis magnetic flux, and a current flowing through the stator winding 259 for generating the q-axis magnetic flux is called a q-axis current. Is referred to as a q-axis inductance.
On the other hand, the magnetic flux flowing through the magnetic path Pd between the centers of the magnetic poles of the rotor is called the d-axis magnetic flux, and the current flowing through the stator winding that generates the d-axis magnetic flux is called the d-axis current. It is referred to as d-axis inductance. In this structure, when the q-axis inductance−d-axis inductance> 0, the current phase is advanced, thereby effectively utilizing the reluctance torque and realizing high efficiency.

[0004]

However, in the above-described conventional configuration, in order to effectively use the reluctance torque, it is necessary to advance the current phase β within the range of 0 ° <β <45 °. When β = 0, the magnet torque is maximized, but there is a disadvantage that the magnet torque cannot be used to the maximum by advancing the current phase to utilize the reluctance torque. Also, a special control circuit was required to advance the current phase.

In order to solve the above-mentioned drawbacks, Japanese Patent Laid-Open Publication No.
In the “rotor structure of synchronous machine and synchronous motor” shown in 3694, the positional relationship between the permanent magnet and the salient pole is examined, and the peak of the magnet torque and the peak of the reluctance torque are matched to amplify the output.

FIG. 26 is a sectional view of a "rotor structure of a synchronous machine and a synchronous motor" disclosed in JP-A-7-143694. The two-pole motor includes a stator 270 and a rotor 261. When a current flows through the winding 269 provided on the stator core 268, the rotor 261 rotates. The rotor 261 has two salient poles 266a, 266b and 2
It has permanent magnets 263a and 263b. The position of the salient pole is shifted from the position 267 of the permanent magnet by an electrical angle of approximately 45 ° toward the rotor rotation forward side. However, in the "rotor structure of synchronous machine and synchronous motor" disclosed in JP-A-7-143694, it is possible to maximize the reluctance torque at the position where the magnet torque is maximum, but the surface area of the magnetic pole is greatly reduced. become. In order to increase the efficiency, it is necessary to provide a structure in which the surface area of the magnetic pole is large and the current phase at which the magnet torque is maximized matches the current phase at which the reluctance torque is maximized.

[0007]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention comprises a rotor core made of a high magnetic permeability material or laminated electromagnetic steel sheets, a shaft passing through the center of the rotor core, and the shaft arranged as a center. In a permanent magnet rotor composed of permanent magnets of several sets of magnetic poles, a structure in which the magnetic flux at an electric angle of approximately 45 ° from the magnetic pole center toward the rotor rotation advance side, that is, the inductance is higher than that of other angles. It was done.

[0008] With the above structure, the reluctance torque can be used most effectively while the magnet torque is sufficiently secured, and the efficiency of the device is improved.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In order to solve the above-mentioned problems, the present invention provides a rotor core made of a high magnetic permeability material or laminated electromagnetic steel sheets, a shaft passing through the center of the rotor core, and a plurality of magnets arranged around the shaft. In a permanent magnet rotor of a DC motor consisting of a plurality of permanent magnets, a structure in which the magnetic flux at an electrical angle of approximately 45 ° from the center of the magnetic pole toward the rotor rotation advance side, that is, the inductance is higher than that at other angles. It is what it was.

In the above structure, a protruding salient pole portion is provided at an electrical angle of approximately 45 ° from the center of the magnetic pole toward the rotation forward side of the rotor. As a result, the point at which the magnet torque becomes maximum coincides with the point at which the reluctance torque becomes maximum, and a motor with high efficiency can be realized by operating at that point.

In addition, a plurality of perforated holes for permanent magnets are arranged near the surface of the rotor core at equal intervals in a concentric arc around the shaft, and the magnetic poles of the permanent magnets inserted into the perforated holes for permanent magnets By providing the rotor core between the perforated holes for permanent magnets at an electrical angle of approximately 45 ° from the center toward the rotor rotation advance side, the permanent magnets are buried inside the rotor core, so that there is no need for means for preventing permanent magnet scattering.

Further, a substantially ring-shaped permanent magnet is provided on the surface of the rotor core, and the distance from the inside of the permanent magnet, ie, the outer periphery of the rotor core, to the center of the rotor core is approximately 45 ° electrical angle from the center of the magnetic pole toward the rotor rotation advance side. By increasing the position of the electrical angle of approximately 45 ° on the reverse side of the rotation of the rotor, the entire outer circumference of the rotor can be made a permanent magnet. By maximizing the magnet surface area, the magnet torque can be maximized. it can.

In a permanent magnet rotor having a plurality of substantially ring-shaped permanent magnets disposed on the surface of a rotor core, the rotor core has a plurality of slits, and the tip of the slit is electrically connected to the rotor rotation advance side from the center of the magnetic pole. In the vicinity of the position of the angle of about 45 °, they gather at a substantially right angle toward the outer periphery of the rotor core, and are formed in a convex shape in the centripetal direction of the rotor. And the reluctance torque can be used effectively.

Further, the slit is formed in an arc shape having a center located at an electrical angle of about 45 ° outside the outer periphery of the rotor core and on the reverse side of the rotation of the rotor, thereby securing a magnetic path inside the rotor core and effectively utilizing reluctance torque. can do.

In a two-pole permanent magnet rotor, a plurality of slits are preferably parallel to a line having an electrical angle of approximately 45 ° on the rotor rotation advance side from a line connecting the magnetic pole centers.

Further, the strength of the rotor core can be increased by filling or embedding the slits with a non-magnetic material or a magnetic material having lower magnetism than the material of the rotor core.

In a two-pole permanent magnet rotor comprising a rotor core made of non-oriented electrical steel sheets laminated in the same rolling direction, a shaft penetrating the rotor core, and a permanent magnet arranged about the shaft, The direction may be parallel to a line having an electrical angle of approximately 45 ° toward the rotor rotation advance side from the line connecting the magnetic pole centers.

Further, in a two-pole permanent magnet rotor comprising a rotor core made of grain-oriented magnetic steel sheets laminated in an easy magnetization direction, a shaft penetrating the rotor core, and a permanent magnet arranged about the shaft, The easy direction may be parallel to a line having an electrical angle of approximately 45 ° on the rotor rotation forward side from the line connecting the magnetic pole centers.

In the case of a permanent magnet rotor of a synchronous motor, a rotor core made of a high magnetic permeability material or laminated electromagnetic steel sheets, a shaft penetrating the center of the rotor core, a permanent magnet arranged around the shaft, A plurality of conductor bars formed around the outer periphery of the rotor core, and a conductor end ring that short-circuits the conductor bars at both end surfaces of the rotor core. When the step-out torque is To and the load torque is Tl,
Electric angle approximately $ 45-CO from rotor center to rotor rotation advance side
By adopting a structure in which the magnetic flux at the position of S ^-1 (Tl / To)｝ ゜, that is, the inductance is higher than that at other angles, the magnet torque and the reluctance torque can be effectively used during the load rotation. It can be used and does not require a starting circuit, and can be started by the current flowing through the conductor bar and the conductor end ring.

Further, by providing one or a few small holes of the number of rotor magnetic poles in the rotor core, accurate positioning can be performed at the time of magnetization, and a jig is inserted into the small hole at the time of magnetization. Thus, it is possible to suppress the rotation of the rotor due to the reluctance torque.

In a permanent magnet rotor of a DC motor having slits, at least one rotor core sheet is provided at each end of the rotor core, and a rotor core sheet having no slit or having a slit smaller than that of another rotor core sheet is laminated. In addition, it is possible to prevent a difference in air gap due to a stress applied to the rotor core during magnet molding or a deformation due to a centrifugal force due to the rotation of the rotor, and to provide a highly accurate and highly efficient motor.

Further, in a permanent magnet rotor of a synchronous motor having a slit and having a conductor bar and a conductor end ring, at least one sheet is provided at each end of the rotor core without a slit or a slit is not formed on the conductor end ring. By laminating rotor core sheets having slits of a size, when die-casting the conductor bar and the conductor end ring integrally, it is possible to prevent the conductor from flowing into the slits and to prevent the deformation of the rotor core due to stress during molding. be able to.

Further, as a method for manufacturing a permanent magnet rotor of a DC motor, a rotor core is formed by laminating rotor core sheets, and then a bond magnet is integrally formed with the rotor core to form a cylindrical rotor, which is magnetized. A permanent magnet rotor can be manufactured with good dimensional accuracy of the rotor core and the permanent magnet and high productivity.

Further, as a method of manufacturing a permanent magnet rotor of a synchronous motor, a rotor core is formed by laminating rotor core sheets, and then the conductor bar and the conductor end ring are integrally die-cast. The magnet is integrally molded into a cylindrical rotor and magnetized, so that the permanent magnet is not damaged or loses magnetism due to heat generated by the molding of the conductor bar and the conductor end ring. Can be manufactured.

In a method of manufacturing a permanent magnet rotor for a synchronous motor having a slit of a number of magnetic poles in a rotor core, after laminating a rotor core sheet to form a rotor core, a conductor bar having at least one end face not short-circuited is replaced with a rotor core. After welding the end face of the conductor bar that is not short-circuited to the conductor end ring, a bond magnet is integrally formed with the rotor core to form a cylindrical rotor,
By magnetizing, it is not necessary to increase the heat to insert the conductor bar formed in advance into the rotor core, without the conductor flowing into the slit, and without breaking the permanent magnet or losing magnetism, with high accuracy, A permanent magnet rotor can be manufactured with good productivity.

[0026]

Embodiments of the present invention will be described below with reference to the drawings.

(Embodiment 1) FIG. 1 is a view showing a cross section of a two-pole permanent magnet rotor of a DC motor according to an embodiment of the present invention. The rotor 11 includes a rotor core 12 made of a high magnetic permeability material such as iron or laminated electromagnetic steel sheets, a shaft (not shown) press-fitted into a shaft hole 14 at the center of the rotor core, and the shaft 11 as a center. Two permanent magnets 13 and a tube 15 for preventing the permanent magnets from scattering
And is rotated in the direction of R by a rotating magnetic field generated by a current rectified by a switching element or the like flowing through a stator winding (not shown). The permanent magnets are arranged at equal intervals on the surface of the rotor core, and have salient pole portions 16 in the form of protrusions between the permanent magnets. The salient pole portion is located at a position 90 ° from the permanent magnet fixing position.
b is at a position of 45 ° toward the rotor rotation forward side. A boundary 17a between the north pole and the south pole exists inside one magnet.

Generally, the torque of a permanent magnet motor having a rotor having reverse saliency as shown in FIG. 25 is as follows: magnet torque TM = PnｎaΨIa ・ cosβ and reluctance torque TR = 0.5 ・ Pn ・ (Lq- Ld) · Ia ²
-It is expressed by the sum with sin2β. Here, Pn is the number of pole pairs, Ψa is the flux linkage by the permanent magnet, Ia is the stator current, Lq is the q-axis inductance, Ld is the d-axis inductance, and β is the current advance angle (electric angle). FIG. 18 shows the magnet torque, the reluctance torque, and the total torque. The magnet torque becomes maximum when β = 0 °, and the reluctance torque becomes maximum when β = 45 °. Therefore, the total torque is maximized within the range of 0 ° <β <45 °. However, the point where the total torque is maximum does not match the point where the magnet torque is maximum and the point where the reluctance torque is maximum,
It cannot be said that the magnet torque and the reluctance torque are used to the maximum. On the other hand, in this embodiment,
By setting the salient pole at 45 ° from the center of the magnetic pole toward the rotation forward side of the rotor, the reluctance torque is TR = 0.5 · Pn
· (Lq-Ld) · Ia ² · cos2β, β = 0
In ゜, both the magnet torque and the reluctance torque are maximized. FIG. 17 shows the magnet torque, the reluctance torque, and the total torque. The maximum value of the total torque is increased by about 20% as compared with FIG. Further, the operation can be performed with the current phase β being 0 °.

(Embodiment 2) FIG. 2 is a view showing a cross section of a four-pole permanent magnet rotor of a DC motor according to another embodiment of the present invention. The configuration, operation, and effects are the same as in the first embodiment, and a description thereof will be omitted. In the case of 4 poles, the electrical angle of 45 ° is the mechanical angle of 22.5
It becomes ゜. Accordingly, the salient pole portion 26 has an electrical angle of 45 ° from the center 27b of the magnetic pole toward the rotor rotation advance side, and a mechanical angle of 22 °.
It is located at 5 ゜. Further, in this embodiment, a permanent magnet is adhered to the core without using a tube to prevent scattering of the permanent magnet.

(Embodiment 3) FIG. 3 is a view showing a cross section of a four-pole permanent magnet rotor of a DC motor according to another embodiment of the present invention. The rotor 31 has four permanent magnet punched holes 38 arranged near the surface of the rotor core 32 at equal intervals around a shaft (not shown) press-fitted into the shaft hole 34 in a concentric arc shape. The rotor core portion 36 between the punched holes for permanent magnets is provided at an electrical angle of 45 ° and a mechanical angle of 22.5 ° on the rotor rotation forward side from the magnetic pole center 37b of the permanent magnet 33 inserted into the punched holes for magnets. A boundary 37a between the north pole and the south pole exists inside one magnet.

The effects are the same as in the first embodiment, and a description thereof will be omitted. In this embodiment, since the permanent magnet is embedded in the rotor core, the rotor core thin portion 35 is present, and the means for preventing the permanent magnet from scattering is not required.

(Embodiment 4) FIG. 4 is a view showing a cross section of a two-pole permanent magnet rotor of a DC motor according to another embodiment of the present invention. The rotor 41 has a substantially ring-shaped permanent magnet 43 on the surface of the rotor core 42, and the distance from the inner side of the permanent magnet, that is, the outer periphery of the rotor core to the center of the rotor core is an electric angle 45 ° from the magnetic pole center 47b toward the rotor rotation advance side. 46a is large, and the position 46b at the electrical angle of 45 ° on the reverse rotation side of the rotor is small. In the case of a two-pole permanent magnet rotor, the shape of the rotor core is an ellipse whose major axis is a line connecting an electrical angle of 45 ° from the magnetic pole center 47b toward the rotor rotation advance side.

The effects are the same as in the first embodiment, and will not be described. In the present embodiment, by using permanent magnets on the entire outer periphery of the rotor, the magnet surface area can be maximized and the magnet torque can be maximized.

When the small hole 45 is provided, it serves as a mark for aligning the center of magnetization at the time of magnetization. Further, by inserting the jig into the small hole and holding down the rotor, it is possible to prevent the rotor from rotating due to the reluctance torque at the time of magnetizing, resulting in incomplete magnetization.

The small holes may be present in the entire rotor core sheet or only in the rotor core sheet at the end of the rotor core.

(Embodiment 5) FIG. 5 is a view showing a cross section of a four-pole permanent magnet rotor of a DC motor according to another embodiment of the present invention. The rotor 51 has a substantially ring-shaped permanent magnet 53 on the surface of the rotor core 52, and the distance from the inside of the permanent magnet, that is, the outer periphery of the rotor core to the center of the rotor core is an electric angle 45 ° from the magnetic pole center 57b toward the rotor rotation advance side. 56a is large, and the position 56b at the electrical angle of 45 ° on the reverse rotation side of the rotor is small.

The effects are the same as in the fourth embodiment, and a description thereof will be omitted. (Embodiment 6) FIG. 6 is a view showing a cross section of a four-pole permanent magnet rotor of a DC motor according to another embodiment of the present invention. The rotor 61 has a ring-shaped permanent magnet 63 on the surface of the rotor core 62, and slits 65a, 65b inside the rotor core.
The tip 66 of the slit gathers at a substantially right angle toward the outer periphery of the rotor core near the position at an electrical angle of 45 ° from the magnetic pole center 67b toward the rotor rotation advance side from the magnetic pole center 67b, and has a convex shape in the centripetal direction of the rotor. There are two slits per magnetic pole. Here, the slit shape is centered at an electrical angle of 45 ° outside the outer periphery of the rotor core and toward the reverse rotation side of the rotor.
8 is an arc shape.

According to this structure, the rotor core is provided with saliency, so that not only the magnet torque but also the reluctance torque can be effectively used. By matching the point at which the magnet torque and the reluctance torque become maximum, the same input can be obtained. Thus, a higher torque can be generated, and a highly efficient motor can be provided.
Further, since the thickness of the permanent magnet can be made uniform, it is easy to mold and is advantageous in the demagnetization proof strength.

In the present embodiment, the slit is formed in an arc shape.
The number of magnetic poles is not limited to four. For example, if the number of magnetic poles increases, the V-shaped shape becomes more advantageous than the arc shape. In the case of an arc-shaped slit, a smooth magnetic path having the same width is formed between the slits in a multilayer structure, which is effective for increasing the reluctance torque.

The number of layers per magnetic pole of the slit can be freely selected. Further, by filling the inside of the slit with a non-magnetic material such as a resin or embedding a substance having a low magnetic permeability, it is advantageous in terms of strength and accuracy.

(Embodiment 7) FIG. 7 is a view showing a cross section of a two-pole permanent magnet rotor of a DC motor according to another embodiment of the present invention. The rotor 71 has a ring-shaped permanent magnet 73 on the surface of the rotor core 72 and a slit 7 inside the rotor core.
5a, 75b and 75c, the slits of which are parallel to a line having an electrical angle of 45 ° on the rotor rotation forward side from a line connecting the opposed magnetic pole centers 77b at a position of 180 °.

The effects are the same as in the sixth embodiment, and a description thereof will be omitted. It is a linear slit, which is easy to process and has good accuracy.

In the case of multi-pole, with the shaft hole as the center,
The slits may be radially arranged by the number of the magnetic poles.

(Embodiment 8) FIG. 8 is a view showing a cross section of a two-pole permanent magnet rotor of a DC motor according to another embodiment of the present invention. The rotor 81 has a ring-shaped permanent magnet 83 on the surface of a rotor core 82 made of grain-oriented electromagnetic steel sheets laminated in the same direction of easy magnetization, and the direction of easy magnetization L is closer to the rotor rotation than the line connecting the magnetic pole centers 87b. Electrical angle 45
Parallel to the ゜ line.

According to this structure, a reluctance torque is generated due to a difference in inductance between the easy magnetization direction and the hard magnetization direction (the direction perpendicular to the easy magnetization direction). In addition, since the point at which the magnet torque and the reluctance torque are maximized coincides with each other, a higher torque is generated with the same input, and a highly efficient permanent magnet motor can be provided.

Processing is easy because the structure is simple.
Excellent in productivity, strength and accuracy.

When a non-oriented electrical steel sheet is used,
It is preferable that the rolling direction is parallel to a line having an electrical angle of 45 ° on the rotor rotation forward side from the line connecting the magnetic pole centers 87b.

This embodiment may be arbitrarily combined with the above embodiment. (Embodiment 9) FIG. 9 is a view showing a cross section of a two-pole permanent magnet rotor of a synchronous motor according to another embodiment of the present invention. The rotor 91 includes a rotor core 92 made of a high magnetic permeability material such as iron or laminated electromagnetic steel sheets, a shaft (not shown) passing through a shaft hole 94 at the center of the rotor core, and two permanent magnets arranged around the shaft. When the step-out torque is To and the load torque is Tl,
The electric angle is approximately 45 from the magnetic pole center 97b toward the rotor rotation advance side.
−COS ⁻¹ (Tl / To)｝ ゜ at the position of the projecting salient pole 9
6. A plurality of conductor bars 99 are provided in the axial direction near the outer periphery of the rotor core, and short-circuited at both end surfaces of the rotor by conductor end rings (not shown).

The rotor is rotated in the direction of R by a rotating magnetic field generated when an alternating current flows through a stator winding (not shown).

According to this structure, the rotor core is provided with saliency, so that not only the magnet torque but also the reluctance torque can be effectively used. By adopting a structure in which the reluctance torque is maximized at the time of load rotation, the same input allows more reluctance torque. A high torque can be generated, and a highly efficient motor can be provided.

Generally, at the time of no-load rotation, a pair of magnetic poles formed by a current flowing through the stator winding comes around the center of the rotor magnetic pole. At the time of step-out, a pair of magnetic poles formed by a current flowing through the stator winding comes at a position at an electrical angle of 90 ° from the center of the rotor magnetic pole to the rotor rotation advance side. During load rotation,
Depending on the weight of the load, a pair of magnetic poles formed by a current flowing through the stator winding between the electrical angle of 0 ° and 90 ° from the center of the rotor magnetic pole toward the rotor rotation side. Therefore,
The delay of the rotor poles under load from the poles created by the current flowing through the stator windings is from electrical angle 0 ° to 90 °.
゜ and the angle is (90−θ), Tl
/ To = cos θ. Since the reluctance torque has a maximum current phase at an electrical angle of 45 ° on the rotor rotation forward side, the electrical angle (4
At the position of (5-θ) ゜, it is preferable that the inductance is maximized. When the load changes, the average load torque or the load torque used for the longest time is Tl.
It should be calculated as

Further, at the time of starting, an induced current flows through the conductor bar and the conductor end ring in accordance with a change in the amount of magnetic flux entering the rotor, so that starting can be performed without a circuit.

In this embodiment, a two-pole permanent magnet rotor is shown, but it may have four poles or more as shown in FIG. As a method for fixing the magnet, in FIG. 9, in addition to a magnet scattering prevention tube 95 of stainless steel or the like, a permanent magnet is bonded to the rotor core as shown in FIG. 10, and a punched hole 118 is provided in the rotor core 112 as shown in FIG. And a method of burying the permanent magnet 113.

Also, as shown in FIGS. 12 and 13 without the salient poles, the outer circumferences of the rotor cores 122 and 132 are not circular, but the electric angle ｛45−COS ⁻¹ from the magnetic pole centers 127b and 137b to the rotor rotation forward side. (Tl / To)｝ ゜ Position 12
6a and 136a are increased, and the position 126b of the electrical angle {45 + COS ^-1 (Tl / To)}
Reluctance torque may be generated by reducing 136b.

As shown in FIGS. 14 and 15, a slit may be provided inside the rotor core. Similarly, as shown in FIG. 16, a rotor 161 is provided with a ring-shaped permanent magnet 163 on the surface of a rotor core 162 made of grain-oriented magnetic steel sheets laminated in the same direction of easy magnetization, and the easy direction L connects the magnetic pole center 167b. Electric angle ｛4 from rotor line to rotor rotation advance side
It may be parallel to the line of 5-COS ⁻¹ (Tl / To)｝ ゜.

That is, the rotor structure, the permanent magnet shape, the salient pole shape, the slit shape, and the like can be variously modified in accordance with the purpose of the present embodiment.

(Embodiment 10) FIG. 19 is a view showing a configuration of a four-pole permanent magnet rotor of a DC motor according to another embodiment of the present invention. The rotor 191 has a substantially ring-shaped permanent magnet 193, and has slits 195 a and 195 b at specific positions inside the rotor core 192. At least one or more rotor core sheets 19 at least on both end faces of the rotor core
8b and 198c are slits 195 smaller than the slits 195a and 195b of the other rotor core sheet 198a.
c, 195d.

With this configuration, it is possible to prevent the air gap from becoming uneven due to the stress applied to the rotor core during the molding of the magnet or the deformation due to the centrifugal force due to the rotation of the rotor.

The permanent magnet is not limited to a substantially ring shape and may be divided into several magnetic poles, or may be embedded in the rotor core.

In FIG. 20, rotor core sheets 208b and 208c without slits are provided on both end surfaces of the rotor core. While increasing the strength of the rotor core, the processing of the rotor core sheet is easy and the productivity is good.

(Embodiment 11) FIG. 21 is a view showing a configuration of a four-pole permanent magnet rotor of a synchronous motor according to another embodiment of the present invention. The rotor 211 has a substantially ring-shaped permanent magnet 213, and has slits 215 a and 215 b at specific positions inside the rotor core 212. A conductor bar hole 219 is provided near the outer periphery of the rotor core. A conductor bar is provided in the conductor bar hole,
a and 220b.

[0062] At least one of each end face of the rotor core
One or more rotor core sheets 218b, 218c are formed with small slits 215c, 2
15d.

According to this configuration, it is possible to prevent the air gap from becoming uneven due to the stress applied to the rotor core during the magnet molding and the deformation due to the centrifugal force due to the rotation of the rotor, and the slit is formed when the conductor bar and the conductor end ring are die-cast. To prevent conductors from flowing into

In FIG. 22, rotor core sheets 228b and 228c having no slit are provided on both end surfaces of the rotor core. While increasing the strength of the rotor core, the processing of the rotor core sheet is easy and the productivity is good.

(Embodiment 12) FIG. 23 shows a method of manufacturing a four-pole permanent magnet rotor of a DC motor according to another embodiment of the present invention. The permanent magnet rotor 231 includes a rotor core 232 in which rotor core sheets 238 are stacked, a shaft (not shown) penetrated through a shaft hole 234 at the center of the rotor core, and a permanent magnet 233 formed in a substantially ring shape.

First, the rotor core sheet 238 is laminated to form the rotor core 232. Next, the bond magnet 233 is integrally formed, and thereafter, magnetized to form the rotor 23.
Let it be 1. Thereby, irrespective of the shape of the rotor core, the dimensional accuracy of the permanent magnet is good, and the accuracy of magnetization can be easily obtained.

Various modifications can be made according to the spirit of the present invention, regardless of the shape of the rotor core, the presence or absence of slits, the presence or absence of salient poles, and the presence or absence of conductor bars and conductor end rings.

When the permanent magnet rotor of the synchronous motor has a conductor bar and a conductor end ring, the rotor core sheet 228a is laminated as shown in FIG.
The conductor bar and the conductor end ring are integrally die-cast, and then a bond magnet 223 is formed and magnetized.

The molding temperature of the bond magnet is 80 to 10
The temperature is around 0 ° C., and when aluminum is die-cast as a conductor, the die-casting temperature is around 600 ° C. Therefore, the permanent magnet rotor can be manufactured without breaking the permanent magnet and losing magnetism by performing die casting first and performing bond magnet molding later.

(Embodiment 13) FIG. 24 is a view showing a method of manufacturing a four-pole permanent magnet rotor of a synchronous motor according to another embodiment of the present invention. A slit 245 is formed in the rotor core 242.
a and 245b, when the conductor bar and the conductor end ring are integrally formed by die-casting, the conductor may flow into the slit. In the present embodiment, the rotor core sheet 248 is laminated to form the rotor core 242, and at least one end face of the preformed conductor bar 240 is opened without short-circuiting to prevent the conductor from flowing into the slit. And the conductor end ring 250 is inserted into the end face that is not short-circuited.
To weld. Thereafter, the bond magnet 243 is formed integrally with the rotor core to form a cylindrical rotor, which is magnetized at a predetermined position to manufacture the rotor 241.

According to this embodiment, a permanent magnet rotor can be manufactured without a conductor flowing into the slit, without breaking the permanent magnet, and without losing magnetism.

The material of the conductor bar and the conductor end ring is preferably aluminum or copper.

Further, the number and cross-sectional shape of the conductor bars, the shape of the conductor end ring, and the like can be variously modified in addition to the present embodiment.

It should be noted that the present invention is not limited to the above embodiment, and various modifications are possible based on the spirit of the present invention, and these are not excluded from the scope of the present invention.

[0075]

As is apparent from the above embodiment, according to the first aspect of the present invention, the peak of the magnet torque and the peak of the reluctance torque can be matched by the shape of the rotor core, and more torque can be generated by the same input. The efficiency of the DC motor can be improved with a simple structure.

According to the ninth aspect, the reluctance torque acts due to the difference in the ease of the magnetic flux by changing the punching direction of the core, which is exactly the same structure as the conventional DC motor, and more torque is applied to the same input. It is possible to improve the efficiency of the DC motor with a simple structure.

According to the tenth aspect, by using a grain-oriented electrical steel sheet, reluctance torque acts due to the difference in the ease of magnetic flux flow, and more torque can be generated with the same input. The efficiency of the DC motor can be improved.

According to the eleventh aspect, the synchronous motor has a structure in which the reluctance torque is maximized at the time of load rotation, so that more torque can be generated with the same input, and the synchronous motor has a simple structure. Efficiency can be improved.

Further, according to the nineteenth aspect, the reluctance torque acts due to the difference in the ease of magnetic flux flow by changing the punching direction of the core, which is exactly the same structure as the conventional synchronous motor, and more torque can be applied to the same input. Can be generated, and the efficiency of the synchronous motor can be improved with a simple structure.

In the twentieth aspect, by using a grain-oriented electrical steel sheet, reluctance torque acts due to the difference in the ease of magnetic flux flow, and more torque can be generated with the same input. The efficiency of the synchronous motor can be improved.

According to the twenty-first aspect, by providing a small hole in the rotor core, it serves as a mark for positioning at the time of magnetization, and the magnetization can be performed with high accuracy.

Further, according to the present invention, it is possible to prevent a gap from being caused due to a deformation caused by a stress applied to the rotor core during magnet molding or a centrifugal force due to the rotation of the rotor, and to provide a highly accurate and highly efficient motor.

In the twenty-third aspect, when the conductor bar and the conductor end ring are integrally formed by die casting, it is possible to prevent the conductor from flowing through the slit.

According to the twenty-fourth aspect, the dimensional accuracy of the rotor core and the permanent magnet is good, and the permanent magnet can be manufactured with high productivity.

According to the twenty-fifth aspect, the permanent magnet rotor can be manufactured with high accuracy and high productivity without breaking the permanent magnet or losing the magnetism due to the heat generated by forming the conductor bar and the conductor end ring.

According to the twenty-sixth aspect, it is not necessary to raise the temperature when burying the conductor bar inside the rotor core.
It is possible to manufacture a permanent magnet rotor without a conductor flowing into the slit of the rotor core and without damaging the permanent magnet or losing magnetism.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a permanent magnet rotor according to an embodiment of the present invention.

FIG. 2 is a configuration diagram of a permanent magnet rotor according to another embodiment of the present invention.

FIG. 3 is a configuration diagram of a permanent magnet rotor according to another embodiment of the present invention.

FIG. 4 is a configuration diagram of a permanent magnet rotor according to another embodiment of the present invention.

FIG. 5 is a configuration diagram of a permanent magnet rotor according to another embodiment of the present invention.

FIG. 6 is a configuration diagram of a permanent magnet rotor according to another embodiment of the present invention.

FIG. 7 is a configuration diagram of a permanent magnet rotor according to another embodiment of the present invention.

FIG. 8 is a configuration diagram of a permanent magnet rotor according to another embodiment of the present invention.

FIG. 9 is a configuration diagram of a permanent magnet rotor according to another embodiment of the present invention.

FIG. 10 is a configuration diagram of a permanent magnet rotor according to another embodiment of the present invention.

FIG. 11 is a configuration diagram of a permanent magnet rotor according to another embodiment of the present invention.

FIG. 12 is a configuration diagram of a permanent magnet rotor according to another embodiment of the present invention.

FIG. 13 is a configuration diagram of a permanent magnet rotor according to another embodiment of the present invention.

FIG. 14 is a configuration diagram of a permanent magnet rotor according to another embodiment of the present invention.

FIG. 15 is a configuration diagram of a permanent magnet rotor according to another embodiment of the present invention.

FIG. 16 is a configuration diagram of a permanent magnet rotor according to another embodiment of the present invention.

FIG. 17 is a diagram showing a relationship between torque and current phase of the permanent magnet motor according to the present invention.

FIG. 18 is a diagram showing a relationship between torque and current phase of a conventional permanent magnet motor.

FIG. 19 is a diagram showing a configuration of a permanent magnet rotor according to another embodiment of the present invention.

FIG. 20 is a diagram showing a configuration of a permanent magnet rotor according to another embodiment of the present invention.

FIG. 21 is a diagram showing a configuration of a permanent magnet rotor according to another embodiment of the present invention.

FIG. 22 is a diagram showing a configuration of a permanent magnet rotor according to another embodiment of the present invention.

FIG. 23 is a view showing a method of manufacturing a permanent magnet rotor according to another embodiment of the present invention.

FIG. 24 is a view showing a method of manufacturing a permanent magnet rotor according to another embodiment of the present invention.

FIG. 25 is a configuration diagram showing a conventional permanent magnet motor.

FIG. 26 is a configuration diagram showing a permanent magnet motor in JP-A-7-143694.

[Explanation of symbols]

11, 21, 31, 41, 51, 61, 71, 81, 9
1,101,111,121,131,141,15
1,161,191,201, 211,221,23
1,241 rotor 12,22,32,42,52,62,72,82,9
2,102,112,122,132,142,15
2,162,192,202,212,222,23
2,242 rotor core 13,23,33,43,53,63,73,83,9
3,103,113,123,133,143,15
3,163,193,203,213,223,23
3,243 permanent magnets 14,24,34,44,54,64,74,84,9
4,104,114,124,134,144,15
4,164,194,204,214,224,23
4,244 Shaft holes 16, 26, 36, 46, 56, 96, 106 Salient pole portions 17b, 27b, 37b, 47b, 57b, 67b, 7
7b, 87b, 97b, 107b, 117b, 127
b, 137b, 147b, 157b, 167b Magnetic pole center 38, 118 Punched hole 45 Small hole 65a, 65b, 75a, 75b, 75c, 145a,
145b, 155a, 155b, 155c, 195a,
195b, 205a, 205b, 215a, 215b,
225a, 225b, 245a, 245b Slits 78, 148, 158 Arc centers 99, 109, 119, 129, 139, 149, 15
9, 169, 240 conductor bar 116 rotor core portion 195c, 195d, 215c, 215d slit (small) 198a, 198b, 198c, 208a, 208b,
208c, 218a, 218b, 218c, 228a,
228b, 228c, 238, 248 Rotor core sheet 219, 229, 249 Conductor bar hole 220a, 220b, 230a, 230b, 250 Conductor end ring T Total torque TM Magnet torque TR Reluctance torque R Rotor rotation direction L Easy magnetization direction Pq q axis Magnetic flux path Pd Magnetic path of d-axis magnetic flux β Lead angle of current phase (electrical angle)

 ──────────────────────────────────────────────────の Continuing from the front page (72) Inventor Kazuhiro Ohara 1006 Kadoma Kadoma, Osaka Prefecture Matsushita Electric Industrial Co., Ltd.

Claims (26)

[Claims] 1. A permanent magnet rotor comprising a rotor core made of a high magnetic permeability material or laminated electromagnetic steel sheets, a shaft penetrating the center of the rotor core, and a plurality of permanent magnets arranged around the shaft. A permanent magnet rotor of a DC motor having a structure in which the magnetic flux at an electrical angle of approximately 45 ° from the rotor rotation advance side, that is, the inductance is higher than that at other angles. 2. A protruding salient pole portion formed by a rotor core is provided between permanent magnets, and the salient pole portion is located at an electrical angle of approximately 45 ° on the rotor rotation advance side from the magnetic pole center. Item 2. The permanent magnet rotor according to Item 1. 3. A permanent magnet having a plurality of punched holes for permanent magnets arranged at equal intervals in a concentric arc around the shaft near the surface of the rotor core, and magnetic poles of the permanent magnets inserted into the punched holes for permanent magnets. 2. The permanent magnet rotor according to claim 1, further comprising a rotor core portion between the perforated holes for permanent magnets at a position at an electrical angle of about 45 [deg.] From the center to the rotor rotation forward side. 4. A substantially ring-shaped permanent magnet is provided on the surface of the rotor core, and the distance from the inner side of the permanent magnet, that is, the outer periphery of the rotor core to the center of the rotor core is set at an electrical angle of about 45 ° from the center of the magnetic pole toward the rotor rotation advance side. 2. The permanent magnet rotor according to claim 1, wherein the position is large, and the position at an electrical angle of approximately 45 [deg.] Is small on the reverse rotation side of the rotor. 5. A permanent magnet rotor having a plurality of substantially ring-shaped permanent magnets disposed on a surface of a rotor core, the rotor core having a plurality of slits, and a tip of the slit is electrically connected to a rotor rotation advance side from a center of a magnetic pole. Near the position at an angle of about 45 °, the rods gather at a substantially right angle toward the outer periphery of the rotor core, and have a shape that is convex in the centripetal direction of the rotor.
2. The permanent magnet rotor according to claim 1, wherein one or more layers are provided per magnetic pole. 6. The permanent magnet rotor according to claim 5, wherein the slit has an arc shape centered at a position at an electrical angle of approximately 45 ° outside the outer periphery of the rotor core and on the reverse side of the rotor rotation. 7. A permanent magnet rotor in which a plurality of substantially ring-shaped permanent magnets are arranged on the outer periphery of a rotor core, the rotor core has a plurality of slits, and the slits connect opposite magnetic pole centers at a position of 180 °. 2. The permanent magnet rotor according to claim 1, wherein said rotor is parallel to a line having an electrical angle of approximately 45 [deg.] On the rotor rotation forward side with respect to the line. 8. The permanent magnet rotor according to claim 5, wherein the slit is filled or embedded with a non-magnetic material or a magnetic material having a lower magnetic property than the material of the rotor core. 9. A two-pole permanent magnet rotor comprising a rotor core made of non-oriented electrical steel sheets laminated in the same rolling direction, a shaft penetrating the rotor core, and a permanent magnet arranged around the shaft. The direction is approximately 45 electrical degrees from the line connecting the magnetic pole centers to the rotor rotation advance side.
A permanent magnet rotor for a DC motor, which is parallel to the line of ゜. 10. A two-pole permanent magnet rotor comprising a rotor core made of grain-oriented electrical steel sheets laminated in an easy magnetization direction, a shaft penetrating the rotor core, and a permanent magnet arranged around the shaft. A permanent magnet rotor for a DC motor, wherein an easy direction is parallel to a line having an electrical angle of approximately 45 ° toward the rotor rotation advance side from a line connecting the magnetic pole centers. 11. A rotor core made of a high magnetic permeability material or laminated electromagnetic steel sheets, a shaft penetrating the center of the rotor core, a plurality of permanent magnets arranged around the shaft, and arranged near an outer periphery of the rotor core. A permanent magnet rotor of a synchronous motor comprising a bar formed by a plurality of conductors and a conductor end ring for short-circuiting the conductor bar at both end faces of the rotor core, wherein a step-out torque is To and a load torque is Tl, Synchronous motor having a structure in which the magnetic flux at the position of an electrical angle of approximately {45-COS ^-1 (Tl / To)}, that is, the inductance is higher than that at other angles, from the center toward the rotor rotation side. Permanent magnet rotor. 12. A permanent magnet rotor in which a plurality of permanent magnets are arranged at equal intervals on the surface of a rotor core, and salient pole portions having a projection shape formed by the rotor core are provided between the permanent magnets. The permanent magnet rotor according to claim 11, wherein the permanent magnet rotor is located at an electrical angle of approximately {45-COS ^-1 (Tl / To)} on the rotor rotation forward side from the magnetic pole center. 13. A permanent magnet having a plurality of punched holes for permanent magnets arranged at equal intervals in a concentric arc around the shaft near the surface of the rotor core, and magnetic poles of the permanent magnets inserted into the punched holes for permanent magnets. 12. The permanent magnet according to claim 11, further comprising a rotor core portion between the perforated holes for permanent magnets at a position at an electrical angle of approximately {45-COS ^-1 (Tl / To)} from the center to the rotor rotation forward side. Rotor. 14. A substantially ring-shaped permanent magnet is provided on the surface of the rotor core.
The distance from the center of the magnetic pole to the rotor rotation advance side has a large electrical angle of approximately {45−COS ⁻¹ (Tl / To)} from the magnetic pole center to the rotor core center, and the electrical angle approximately {45+
The permanent magnet rotor according to claim 11, wherein the position of COS ^-1 (Tl / To)｝ ゜ is small. 15. A permanent magnet rotor having a plurality of substantially ring-shaped permanent magnets disposed on the surface of a rotor core, the rotor having a plurality of slits inside the rotor core, and the tip of the slit is electrically moved forward from the center of the magnetic pole toward the rotor rotation. Square approximately $ 45-C
12. The magnetic flux gathers at a right angle toward the outer periphery of the rotor core near the position of OS ^-1 (Tl / To)｝ ゜, has a convex shape in the centripetal direction of the rotor, and the slit has one or more layers per magnetic pole. A permanent magnet rotor as described. 16. An electrical angle of approximately 45 + COS ^-1 (Tl /
2. An arc shape having a center at the position To)｝ ゜.
5. The permanent magnet rotor according to 5. 17. A permanent magnet rotor having a plurality of substantially ring-shaped permanent magnets arranged on the outer periphery of a rotor core, wherein the rotor core has a plurality of slits, and
12. The method according to claim 11, wherein the electric angle is substantially parallel to a line having an electrical angle of approximately {45-COS ^-1 (Tl / To)} on the rotor rotation forward side from a line connecting the magnetic pole centers facing each other at the position of ゜. Permanent magnet rotor. 18. The permanent magnet rotor according to claim 15, wherein the slit is filled or embedded with a non-magnetic material or a magnetic material having a lower magnetic property than the material of the rotor core. 19. A two-pole permanent magnet rotor comprising a rotor core made of non-oriented electrical steel sheets laminated in the same rolling direction, a shaft penetrating the rotor core, and a permanent magnet arranged about the shaft. A permanent magnet rotor for a synchronous motor, wherein the direction is parallel to a line having an electrical angle of approximately {45-COS ^-1 (Tl / To)} on the rotor rotation forward side from a line connecting the magnetic pole centers. 20. A two-pole permanent magnet rotor comprising a rotor core made of grain-oriented magnetic steel sheets laminated in an easy magnetization direction, a shaft penetrating the rotor core, and a permanent magnet arranged around the shaft. A permanent magnet rotor for a synchronous motor, wherein an easy direction is parallel to a line having an electrical angle of approximately {45-COS ^-1 (Tl / To)} on the rotor rotation forward side from a line connecting the magnetic pole centers. 21. A permanent magnet rotor having a permanent magnet rotor structure according to any one of claims 1 to 20, wherein a small hole is provided in said rotor core. 22. The structure of the permanent magnet rotor according to any one of claims 5 to 7, wherein at least one sheet is provided at each end of the rotor core, without slits, or with respect to slits of another rotor core sheet. A permanent magnet rotor for a DC motor in which rotor core sheets having small slits are laminated. 23. The structure of the permanent magnet rotor according to any one of claims 15 to 17, wherein at least one rotor core is provided at each end of each of the rotor cores, and no slit is formed on the conductor end ring. A permanent magnet rotor of a synchronous motor in which rotor core sheets having slits of various sizes are laminated. 24. The method of manufacturing a permanent magnet rotor according to claim 1, wherein a rotor core is formed by laminating rotor core sheets, and then a bond magnet is integrally formed with the rotor core to form a cylindrical shape. A method of manufacturing a permanent magnet rotor, wherein the rotor is magnetized. 25. The method for manufacturing a permanent magnet rotor according to claim 11, wherein said conductor bar and said conductor end ring are integrally formed after laminating rotor core sheets to form a rotor core. A method for manufacturing a permanent magnet rotor of a synchronous motor, in which, after die-casting, a bond magnet is integrally formed with a rotor core to form a cylindrical rotor and magnetizes. 26. The method for manufacturing a permanent magnet rotor according to claim 11, wherein after the rotor core sheets are laminated to form the rotor core, at least one of the end faces is not short-circuited. After the conductor bar is inserted into the rotor core and the end face of the conductor bar that is not short-circuited is welded to the conductor end ring, a bond magnet is integrally formed with the rotor core to form a cylindrical rotor, and the magnetizing is performed. Production method.