JPH10271723A - Permanent magnet field type rotating electric machine and method of manufacturing the same - Google Patents

Abstract

(57) [Problem] To provide a permanent magnet field type rotating electric machine capable of satisfactorily magnetizing a field R-Fe-B magnet and a method of manufacturing the same. Further, there is provided a permanent magnet field type rotating electric machine which is inexpensive and maintains high performance when a sintered magnet is used as a field magnet. SOLUTION: An R-Fe-B magnet (R
Is one or two of rare earth elements such as Nd and Dy including Y
), Wherein the permeance coefficient (Pcm) and the residual magnetic flux density (Br) of the R-Fe-B magnet in the state of the rotor alone are provided. : KG) and (Pcm + 1)> Br /
7. A permanent magnet field type rotating electric machine characterized by satisfying the relationship of 7.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an R
The present invention relates to a rotating electric machine with good magnetization of an Fe-B magnet and a method for manufacturing the same. The present invention also relates to a permanent magnet field type rotating electric machine in which the processing of the provided field magnet is simplified, inexpensive, and has high performance.

[0002]

2. Description of the Related Art Recent improvements in the properties of permanent magnet materials are remarkable. For example, R-Fe-B based rare earth magnets (R is one or two of rare earth elements such as Nd and Dy including Y) These elements, hereinafter abbreviated as R-Fe-B magnets) are widely used mainly in light, thin and small fields (for example, motors for driving a head actuator of a hard disk drive) because of their extremely high magnetic properties. Have been. In recent years, R-Fe-B magnets that can withstand high temperatures have been developed,
A large rotating electric machine whose output exceeds 10 kW (for example,
Motors for driving electric vehicles. ) Has also begun to be used. However, while the R-Fe-B magnet has high magnet properties, it is possible to bring out 100% of its unique excellent magnet properties when magnetizing it while being arranged as a field magnet in a rotating electric machine. There are many cases where a sufficient magnetizing magnetic field strength cannot be secured.

[0003] The inventors of the present invention have conducted intensive studies on the magnetizing conditions of the R-Fe-B magnet incorporated in the permanent magnet field type rotating electric machine. As a result, the residual magnetic flux density (Br) of the R-Fe-B magnet was 90%.
It was confirmed that a large number of magnetization failures occurred at 00G or more.

[0004] In a conventional surface magnet type rotor 105 shown in a perspective view of FIG.
Although the Fe-B magnet 103 is arranged, this magnet 103
Is placed on the rotor 105 after magnetizing the
The permeance coefficient in magnetizing the magnet 103 alone is often 0.5 or less, and even if the applied magnetic field is increased, an incompletely magnetized portion may remain inside the magnet 103. Absent. On the other hand, unmagnetized Nd-F
There is a method of magnetizing the Nd-Fe-B magnet 103 in a state of the surface magnet type rotor 105 on which the e-B magnet 103 is arranged. It is necessary to design and manufacture, and it is not practical because of high cost. Further, when the rotor 105 magnetized by this method is incorporated into the rotating electric machine 200 shown in FIG.
Since a strong magnetic attraction force acts between the electric motor 05 and the stator 104, this assembling operation involves difficulty, and the rotating electric machine 2
If the size of 00 becomes large, it is very dangerous unless an appropriate mounting jig is used.

As a proposal for improving the difficulty of the assembling work, there is a method of performing magnetization using a magnetic field generated in a stator winding in a state of a completed rotating electric machine, which will be described with reference to FIG. In the rotating electric machine 200 shown in FIG. 12, a current flows through, for example, the U-phase winding 115 and the V-phase winding 116 of the stator 104, and the magnetizing magnetic field generated from these stator windings flows through the field magnet 103 of the rotor 105. And magnetizing can be performed. Portion 10 for applying U, V, and W phase windings of stator 104
Reference numeral 8 denotes a recess provided in the stator iron core called a slot. Further, the convex portion 109 sandwiched between the slots 108 is called a tooth or a tooth portion. According to this magnetizing method, a dedicated jig for magnetizing is not required, but the magnetic flux generated by the winding concentrates on the teeth 109 of the iron core. Since the magnetizing magnetic field is low, and the magnetizing magnetic field is high in the portion of the field magnet 103 facing the tooth portion (stator magnetic pole) 109, the magnetizing rate of the field magnet 103 partially varies and uniformity occurs. A magnetized magnet cannot be obtained. In the permanent magnet field type rotary electric machine 200 in which the field magnet 103 having poor magnetization is arranged, the field magnet 10
Since the amount of generated magnetic flux of No. 3 locally fluctuates, the performance of the rotating electric machine is reduced.

Next, when a known sintered magnet (for example, an Nd-Fe-B-based anisotropic sintered magnet or the like) is used as a field magnet, a grinding wheel using a grinding wheel or the like is used. The actual condition is that the black scale on the surface of the magnet body after sintering is removed by mechanical grinding such as surface grinding to give a predetermined dimensional accuracy, and the processing cost due to the poor processing efficiency of the sintered magnet This is one of the factors that hinders the cost reduction of permanent magnet field type rotating electric machines. On the other hand, an unprocessed sintered magnet (entire black scale) is used as the field magnet 103 for the rotating electric machine 2 shown in FIG.
If it is arranged at 00, the air gap 106
It is difficult to realize a high-performance rotating electric machine because the thickness of the magnetic head becomes uneven and the amount of generated magnetic flux varies.

[0007]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a permanent magnet field type rotating electric machine capable of satisfactorily magnetizing the mounted field R-Fe-B magnet and a method of manufacturing the same. It is. In addition, taking into account the dimensional variation and poor processability of the sintered magnet used as the field magnet (the entire surface is black scale), the processing cost of the sintered magnet is maintained while maintaining high performance. An object of the present invention is to provide an inexpensive permanent magnet field type rotating electric machine that is suppressed.

[0008]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, a permanent magnet field type rotating electric machine according to the present invention has an R-type rotor inside a rotor core.
A permanent magnet field type rotating electric machine including an internal magnet type rotor having an Fe-B magnet (R is one or two or more rare earth elements such as Nd and Dy including Y), The permeance coefficient (Pcm) and the residual magnetic flux density (Br: kG) of the R-Fe-B magnet in the state of the child alone are:
(Pcm + 1)> Br / 7. According to the present invention, if the effective magnetic field intensity applied to the field R-Fe-B magnet of the permanent magnet field type rotating electric machine is set to 15 kOe or more in a normal temperature environment, the magnetic field is almost completely attached to the R-Fe-B magnet. Good magnetization with a magnetic susceptibility of 100% can be provided, and the characteristics of the permanent magnet field type rotating electric machine can be stably maintained at a high level. That is, it is possible to suppress the occurrence of uneven magnetization of the field magnet, which tends to occur in the magnetization of the conventional rotating electric machine, and to stably improve the characteristics of the rotating electric machine. Here, the state of the rotor alone refers to a state in which an external magnetic field is not substantially applied to the rotor other than the earth magnetic field, that is, a state in which a magnetic substance does not exist near the rotor.

Further, the present invention provides a stator having a plurality of stator magnetic poles and a winding for generating a rotating magnetic field on the stator magnetic pole, a rotating shaft and a stator shaft provided on the rotating shaft. The rotor rotates in opposition and the R-Fe-
B magnet (R is one of rare earth elements such as Nd and Dy including Y
And two or more types), an internal magnet type rotor having a space at an end of the R-Fe-B magnet, and a magnetic pole position of the rotor facing the stator magnetic pole, and according to the detected position. A permance coefficient (Pcm) and a residual magnetic flux density (Br: kG) of the R-Fe-B magnet in the state of the rotor alone,
A permanent magnet field type rotating electric machine characterized by satisfying a relationship of (Pcm + 1)> Br / 7. According to the present invention, the magnetizing rate of the field R-Fe-B magnet of the rotating electric machine of the present invention is determined by the limited rotating magnetic field strength of the stator of the conventional structure. R-Fe for magnet
The magnetism can be made better than the magnetization rate of the -B magnet, and the magnet is highly practical.

The present invention is also directed to a permanent magnet field type rotating electric machine having an internal magnet type rotor having a sintered magnet inside a rotor core, wherein the surface of the sintered magnet has an unprocessed black magnet. A permanent magnet field type rotating electric machine having a skin portion, wherein the black skin portion is arranged to face a space provided inside the rotor core. According to the present invention, the dimensional variation of the unprocessed black scale portion of the sintered magnet having inferior dimensional accuracy can be absorbed by the space provided in the rotor core in the longitudinal direction of the rotating shaft, thereby simplifying the processing of the sintered magnet. It is possible to reduce the cost while maintaining the high performance of the rotating electric machine. Here, it is preferable that this space is not provided on the magnetization direction side of the sintered magnet in order to maintain high characteristics of the rotating electric machine. Therefore, it is preferable that the portion having the black scale is a portion other than the magnetization direction side of the sintered magnet.

The rotor core constituting the internal magnet type rotor incorporated in the rotating electric machine of the present invention is made of any one of silicon steel, magnetic stainless steel, soft iron, permalloy, amorphous soft magnetic alloy, and nanocrystalline soft magnetic alloy. It is preferable to use one or two or more of them. Rotor core thickness 0.05 ~
It is preferable from the viewpoint of eddy current resistance that a 1 mm thin plate is formed by laminating in the longitudinal direction of the rotating shaft.

Further, R-Fe in the internal magnet type rotor is used.
It is preferable that the minimum thickness of the rotor core between the -B magnet and the outer peripheral surface of the rotor core is 0.5 to 5 mm. If the thickness is less than 0.5 mm, it is difficult to configure the rotor so as to satisfy the relational expression in the rotor alone state.
-Magnetization rate is remarkably reduced because a poorly magnetized portion is easily generated in a local portion of the Fe-B magnet, and when it exceeds 5 mm, the magnetic flux generated from the magnetized R-Fe-B magnet is rotated with the minimum thickness. A short circuit occurs in the daughter core portion, and the amount of interlinkage magnetic flux is reduced, which is not preferable.

Further, the present invention provides a stator having a plurality of stator magnetic poles, a winding for generating a rotating magnetic field in the stator magnetic pole, a rotating shaft, and a rotating shaft provided to face the stator magnetic pole. And the rotor core has R-Fe-
B magnet (R is one of rare earth elements such as Nd and Dy including Y
(Or two or more types), and a control circuit that detects a magnetic pole position of the rotor facing the stator magnetic pole and supplies a current to the winding according to the position. In a method of manufacturing a permanent magnet field type rotating electric machine having
The rotor was configured such that the permeance coefficient (Pcm) and the residual magnetic flux density (Br: kG) of the R-Fe-B magnet in the rotor alone state satisfied the relationship of (Pcm + 1)> Br / 7. Thereafter, the rotor is disposed opposite to the stator via an air gap to form a permanent magnet field type rotating electric machine, and then the R-Fe-B magnet is formed by a magnetic field generated by energizing the winding. And a method for manufacturing a permanent magnet field type rotating electric machine characterized by magnetizing.
According to the present invention, the rotating magnetic field generated by the stator having the conventional configuration can impart a magnetizing rate of almost 100% to the field R-Fe-B magnet, and the magnetized field magnet can be used alone or The number of assembling steps can be reduced and safer than a conventional method of manufacturing a rotating electric machine that is incorporated into a rotating electric machine as a part. Furthermore, it is possible to avoid a problem that the shavings and shavings are magnetically attracted around the magnet rotor when it is necessary to cut a part of the rotor in order to balance the rotation.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail. The present inventors have studied the difficulty of magnetizing the field R-Fe-B magnet of the rotating electric machine, and obtained the following findings. FIG. 8 shows three Nd-
Fe-B magnet (another method sintered magnet manufactured by Hitachi Metals, Ltd.):
The results of evaluating the magnetizability using a, b, and c are shown. Magnetization rate is (magnetization rate) = (magnetic flux generated by magnetized permanent magnet) / (magnetic flux generated when full magnetization is performed so that the maximum magnetic flux density of the permanent magnet is saturated) × 100
It is a value defined by (%). The horizontal axis in FIG. 8 represents the magnetizing magnetic field strength when the magnet alone is magnetized by the air-core type solenoid coil. In FIG. 8, the Nd-Fe-B magnet has a smaller intrinsic coercive force (iHc) and a larger residual magnetic flux density (Br) as the rightmost one in the order of c, b, and b.
The permeance coefficient (Pc) of each magnet alone is set to 1. The permeance coefficient (Pc) is defined as Pc, where -H is the magnetic field strength in the direction opposite to the magnetic field direction generated by the permanent magnet, and B is the magnetic flux density generated inside the permanent magnet when -H is applied to the permanent magnet. = B / H. The magnetic field strength -H is a value including not only a magnetic field applied by an external current or the like but also a so-called demagnetizing field generated inside the magnet. From FIG. 8, it can be seen that the magnetization characteristics when the magnets are magnetized alone differ depending on the difference in the magnet characteristics of A, B and C.

Conventionally, the difference between a, b, and c has been considered to be due to a difference in intrinsic coercive force (iHc). However, it has been found that the difference is actually different. Hereinafter, the obtained knowledge will be described. Considering the demagnetizing field for the difference between the individual magnetizing characteristics of the Nd-Fe-B magnets a, b, and c, it will be described later that this difference is caused by the difference in the magnitude of the effective magnetizing magnetic field inside each magnet. I understood as follows. Permanent magnets have the property of forming a demagnetizing field when magnetized.For example, when magnetizing a single magnet with an air-core solenoid coil, the demagnetizing field is subtracted from the externally applied magnetic field. The effective magnetic field strength used for In the present invention, the strength of the magnetic field effectively used for magnetization inside the magnet is referred to as an effective magnetic field. The strength of the effective magnetic field is defined by the following relational expression. (Effective magnetic field strength) = (Externally applied magnetic field strength)-(Demagnetizing field strength) (1)

The strength of the demagnetizing field can be determined, for example, from the initial magnetization curve shown in FIG. In FIG. 9, the Nd-Fe-
The initial magnetization curve is measured by inserting the B magnets A, B, and C into a closed magnetic circuit to increase the permeance coefficient, and neglecting the generation of a demagnetizing field during the magnetization process. The horizontal axis indicates the applied magnetic field intensity H (kOe), and the vertical axis indicates the magnetization intensity: 4πI (kG). The strength of the demagnetizing field when a permanent magnet having an arbitrary permeance coefficient Pc is magnetized in a predetermined magnetic circuit is given by equation (2). (Strength of demagnetizing field) = (Strength of magnetization of permanent magnet) × {1 / (Pc + 1)} (2) From equations (1) and (2), (Effective field strength) = (Externally applied magnetic field) (Intensity of magnetization) − (magnetization intensity of permanent magnet) × {1 / (Pc + 1)} (3)

FIG. 10 is a re-plot of the data of FIG. 8 to the relationship between the strength of the effective magnetic field and the magnetization rate obtained by using the equation (3). From FIG. 10, Nd-Fe-B magnet b,
Both (b) and (c) have a magnetization rate substantially coincident with the effective magnetic field, and it can be seen that the effective magnetic field at which the magnetization rate becomes about 100% is about 15 kOe at room temperature. further,
According to the study of the present inventors, the effective magnetic field is about 15
At kOe or more, the magnetizability is almost saturated with R-Fe-B
It was confirmed that it was a common property of magnets. In fact, FIG.
In order to verify the result of 0, the Nd-Fe-B magnet b
(B) and (c) are each incorporated into a magnetic circuit with Pc> 10, and the magnetization characteristics are measured in a state where the influence of the demagnetizing field is eliminated.
Magnetization characteristics similar to those in FIG. 10 were obtained. The above findings are summarized as follows. The magnetization rate of the R-Fe-B magnet is almost constant with respect to the effective magnetic field. Since the magnitude of the demagnetizing field induced according to the magnitude of the externally applied magnetizing magnetic field varies depending on the difference in the permanent magnet characteristics, the apparent (Br) of the magnetization has a low permeance coefficient such as the magnet alone. The magnetizing characteristics of the small permanent magnet look good. Based on these findings, the present inventors have found that R-Fe-B
A magnetic circuit for improving the magnetization of the magnet was studied. Equation (3) is modified so that (the strength of the externally applied magnetic field) − (the strength of the effective magnetic field) = (the strength of the magnetization of the permanent magnet) × {1 / (Pc + 1)} (4). As described above, the value of (effective magnetic field strength) in the expression (4) is required to be 15 kOe or more for the R-Fe-B magnet. In addition, the field R-F
When magnetizing an e-B magnet, the intensity of the magnetizing magnetic field that can be generated is 22 k at room temperature (for example, 20 ° C.) for practical use.
Oe is the largest. That is, (the strength of the externally applied magnetic field) in the equation (4) is 22 kOe or less. In consideration of these, the expression (5) is derived from the expression (4). 22-15 = 7 (kOe) = (magnetization strength of R-Fe-B magnet) × {1 / (Pc + 1)} (5) (5) Equation (5): Magnetization strength of (R-Fe-B magnet) ) Is known to be the residual magnetic flux density Br at the maximum, and the equation (6) is obtained by modifying the equation (5) with this condition. (Pc + 1)> Br (kG) / 7 (kOe) (6) When the expression (6) is satisfied, good magnetization that can sufficiently bring out the magnetic characteristics of the field R-Fe-B magnet is performed. Rotating electric machine can be realized. When magnetizing the field R-Fe-B magnet using the windings of the rotating electrical machine, the cross-sectional area itself of the teeth on which the windings are applied is small in order to secure the cross-sectional area of the slot. Value. For this reason, the teeth become saturated due to the magnetic flux induced by the current flowing through the winding at the time of magnetization. Therefore, when calculating the permeance coefficient of the field R-Fe-B magnet, the magnetic material of the teeth is considered. It is necessary to calculate only the rotor core on which the R-Fe-B magnet is installed, without using the R-Fe-B magnet.

Next, the present invention will be described with reference to examples.
FIG. 1 is a cross-sectional view of a principal part showing one embodiment of the rotating electric machine of the present invention. 1, the same components as those in FIG. 14 are denoted by the same reference numerals. The permanent magnet field type rotary electric machine 10 of FIG. 1 is an example configured as an electric motor, and an internal magnet type rotor 5
0 and a stator 104. Internal magnet type rotor 5
Numeral 0 denotes a plate-like Nd-Fe-B magnet 1 (for example, a soft magnetic rotor core 2 having a magnetic pole shown in the drawing) arranged around a rotation axis 5 (for example, made of SUS304). Anisotropic sintered magnet manufactured by Hitachi Metals, Ltd .; HS-35
A rectangular plate having a width of 20 mm, a length of 4 mm, and an axial direction of 50 mm. ) Are buried in a substantially square shape so that symmetrical four poles can be formed at equal intervals in the rotation direction of the outer peripheral surface of the internal magnet type rotor 50. A substantially triangular space 3 is formed at both ends of the Nd—Fe—B magnet 1,
The short-circuit flux Фs between adjacent magnetic poles, which is schematically shown by a dotted line, can be suppressed, and even if the end face 1a of the Nd-Fe-B magnet 1 is an unprocessed part of a black scale specification and its dimensions vary, the space can be reduced. 3 allows the dimensional variation of the end face 1a to be absorbed. Therefore, Nd-Fe-
Since the Nd-Fe-B magnet 1 can be finished to the final shape only by simple mechanical processing such as surface grinding of both surfaces 1b, which are the pole faces of the B magnet 1, it is advantageous for cost reduction, and as in the following relational expression: The rotor 50 is constituted. Rotor core 2
A space 3 is formed in the space 3 in an axial direction according to the fixed state of the Nd-Fe-B magnet 1, and its shape and dimension are about the degree of dimensional variation of the black scale portion 1 a and the magnetic force of the internal magnet type rotor 50. It is set as appropriate from the constraint conditions of the circuit. A known magnet can be used as the sintered magnet having a black scale, and a magnet in which the end face 1a is lightly processed to partially leave the black scale may be used. The permeance coefficient (Pc) of the Nd—Fe—B magnet 1 in the rotor 50 alone state
m) and the residual magnetic flux density (Br: kG) are given by (P
cm + 1) = Br / 3.5, and showed good characteristics as the rotating electric machine 10. Further, the Nd-Fe-B magnet 1
T1 of the minimum thickness portion between the rotor core 2 and the outer peripheral surface thereof
Is 0.5 to 5 mm. Under this configuration, Nd-F
Magnetized surface (magnetic pole surface) 1b of eB magnet 1 and air gap 4
, The unevenness in the intensity of the magnetizing magnetic field generated in the slot portion 108 and the tooth portion 109 in the above-described conventional rotary electric machine 200 is suppressed, and leveling is performed inside the soft magnetic rotor core 2. As a result, the magnetization characteristics of the Nd—Fe—B magnet 1 are improved. However, if the t1 dimension was less than 0.5 mm, (Pcm + 1)> Br / 7 could not be satisfied. If the t1 dimension exceeds 5 mm, the Nd-
The magnetic flux generated from the Fe-B magnet 1 is equal to t1 of the rotor core 2.
The short circuit easily occurs inside the rotor core 2 through the portion, and the amount of effective interlinkage magnetic flux guided to the stator 104 is extremely reduced, so that it is difficult to improve the characteristics of the rotating electric machine.

On the stator 104 side in FIG. 1, three-phase star-connected windings (U-phase 115, V-phase 116, W-phase 117) are provided, and these windings generate a rotating magnetic field. In synchronization with the rotating magnetic field, the internal magnet type rotor 50 having the Nd-Fe-B magnet 1 which is well magnetized by the magnetizing method of the present invention described below rotates. The diameter of the rotor 50 is about 50 mm, and the axial length of the rotating shaft 5 is about 80 mm. The rotor core 2 and the stator core 1
10 is formed using a 3.5% silicon steel plate. It is preferable from the viewpoint of eddy current resistance that the rotor core 2 and the stator core 110 are formed by laminating the above silicon steel sheets (for example, those having a thickness of 0.45 mm).

FIG. 2 is a schematic diagram showing an example of a connection configuration between the U, V, and W phase windings and a capacitor used as a power supply for magnetization. Although FIG. 2 schematically shows one capacitor 21, in the rotary electric machine 10, a large number of capacitor groups are actually connected in series and / or in parallel to obtain predetermined withstand voltage and capacitance. .

In the rotating electric machine 10 shown in FIG. 1, a predetermined magnetic force sufficient for practical use is applied to the non-magnetized field Nd-Fe-B magnet 1 so as to form a 4-pole rotating motor as shown in FIG. The magnetizing method of the present invention for forming the element 50 will be described below. (Embodiment) The capacitance of the capacitor 21 of FIG.
It is fixed at 500 μF, a predetermined voltage is applied to this capacitor 2, and after a sufficient time has passed, the switch S is closed and FIG.
A half-width current of about 4 msec was passed through the windings (U-phase and V-phase) to magnetize the Nd-Fe-B magnet 1. This Nd-
As the Fe-B magnet 1, the Nd-Fe-
Magnetization is performed using Nd-Fe-B magnets A, B, and C having the same material and magnetic properties as the B magnets A, B, and C, respectively.
The current flowing through the winding varies depending on the applied voltage, and has a peak value of about 200 to 600A. Nd-Fe-B with respect to the capacitor charging voltage of the rotating electric machine 10 in this magnetization
FIG. 3 shows the relationship between the magnetization rates of A, B, and C as the magnet 1. From FIG. 3, it was found that when the capacitor charging voltage was 2500 V or higher, the field Nd-Fe-B magnets A, B, and C of the present invention had sufficient magnetization rates. In addition, in FIG. 3, A has a relationship of (Pcm + 1)> Br / 3.8, B has a relationship of (Pcm + 1)> Br / 3.5, and C has a relationship of (Pcm + 1)> Br / 3.25.

(Comparative Example) As a comparative example, in the rotating electric machine 200 shown in FIG. 12, the Nd-Fe-B magnet 103 (Hitachi Metal Co., Ltd.)
The result of evaluating the magnetization rate of (S-35CH) is shown in FIG. From FIG. 4, the magnetizing rate of the Nd—Fe—B magnet 103 cannot be said to be sufficient even at the initial voltage of 2500 (V), and the magnetizing rate is very poor as compared with those of the examples a, b, and c. P
cm + 1)> Br / 7. The following two factors can be cited as factors of the poor magnetization. 1) Nd-Fe-B magnet 103 in winding of rotating electric machine 200
When as much current as possible is passed to magnetize the rotor, the teeth 109 of the iron core on which the windings of the rotating electric machine 200 are wound become saturated, and face the teeth 109 with the air gap 106 therebetween. The Nd—Fe—B magnet 103 cannot sufficiently serve as an iron core for increasing the permeance coefficient of the portion. 2) The magnetic flux for magnetizing the Nd-Fe-B magnet 103 concentrates on the teeth 109, and the portion of the Nd-Fe-B magnet 103 facing the teeth 109 is selectively magnetized, Not uniformly magnetized. In view of these inconvenience factors, as described above, the present invention employs a unique internal magnet type rotor configuration in which the R-Fe-B magnet is disposed inside the rotor core, so that the conventional magnetization failure can be avoided. it can.

The present invention is not limited to the configuration of the internal magnet type rotor in which the plate-like Nd-Fe-B magnet is disposed inside the rotor core, but is not limited to the configuration in which the arc-shaped field magnet 71 shown in FIG. Magnet type rotor 70, internal magnet type rotor 8 in which block-shaped field magnet 81 shown in FIG. 6 is arranged in the same magnetic pole repulsion type
0, the configuration of the internal magnet type rotor 90 using the reverse arc-shaped field magnet 91 shown in FIG. Further, substantially triangular spaces 74, 84, and 94 shown by dotted lines in FIGS. 5 to 7 are arranged so as to face each other than the pole faces of the field magnets, and each field magnet is connected to the end face 7 thereof.
The anisotropic sintered magnets 1a, 81a, and 91a may be black scale or partially black scale. In this case, the pole faces 71b, 81b, 9 of the respective sintered magnets 71, 81, 91
1b is processed within a predetermined dimensional tolerance, so that it is possible to reduce the processing cost and maintain substantially the same as the case of using an anisotropic sintered magnet in which the rotating electrical machine characteristics are entirely processed.

In the above embodiment, the example of the inner rotor type rotating electric machine in which the rotor containing the permanent magnet is arranged inside the stator to face each other has been described, but it is needless to say that the present invention can be applied to the outer rotor type. The present invention is also applicable to a generator. Further specifically, when (a) the permanent magnet is arranged on the stator and the rotor is arranged inside the stator, (b) the permanent magnet is arranged on the stator (C) a configuration in which the rotor is disposed outside the stator, and (c) a configuration in which the rotor is disposed outside the stator, and (c) a configuration in which the rotor is disposed outside the stator. ) A permanent magnet is arranged on the rotor, and
The present invention can be widely applied to a configuration in which a stator and a rotor face in the axial direction, (e) a configuration in which a permanent magnet is disposed on the stator, and a configuration in which the stator and the rotor face in the axial direction. It is possible.

In the above embodiment, Nd is used as the field permanent magnet.
Although the configuration and manufacturing method of a rotating electric machine using an anisotropic sintered magnet of the Fe-B type have been described, the present invention relates to a known R-Fe
The present invention is applicable to a material which is a -B magnet which is difficult to fully magnetize to its inherent high magnet characteristics in a state where the magnet is incorporated in a conventional rotating electric machine. As an example of an R-Fe-B magnet to which the present invention can be applied, an R-Fe-B system may be used, but an R-Fe- (Co) -BM system is preferable, and R includes Y. One or more of the rare earth elements is 25 to 35
% By weight, B is 0.8 to 1.2% by weight, M is Al, Nb,
Ti, V, Zr, Mo, W, Ga, Cu, Zn, Ge,
One or more of Sn is 5% by weight or less, and the balance is Fe or Fe and Co excluding an unavoidable mixture. Nd-Fe-B-Al-Nb, Nd
-Fe-Co-B-Al-Nb, Nd-Fe-B-Al
-Ga, Nd-Fe-Co-B-Al-Ga, Nd-D
y-Fe-B-Al-Nb, Nd-Dy-Fe-Co-
B-Al-Nb, Nd-Dy-Fe-B-Al-Ga,
Examples include anisotropic sintered magnets such as Nd-Fe-Dy-Co-B-Al-Ga, and bonded magnets using one or more of these powders, but are not limited thereto. Absent.

In the above-described embodiment, an example has been described in which four symmetrical magnetic poles are formed at equal intervals in the rotation direction of the outer peripheral surface of the internal magnet type rotor, but an asymmetrical magnetic pole configuration having different magnetic pole intervals may be used. Further, the number of magnetic poles is not limited.
A configuration of ~ 100 poles is very useful.

[0027]

As described above, the present invention has the following excellent effects. (1) In a rotating electric machine in which an R-Fe-B magnet for field having Br of 9 kG or more is arranged, the R-Fe-B magnet is made almost uniform and good by utilizing a magnetic field formed by a stator winding having a conventional configuration. So that the R-Fe-B
Magnetization can be performed up to the magnet characteristic level very close to the magnet characteristics inherent to the magnet, which greatly contributes to the characteristics variation and improvement of heat resistance as a rotating electric machine. (2) The R-Fe-B magnet for field incorporated in the unmagnetized state in the permanent magnet field type rotating electric machine can be almost uniformly and safely magnetized, so that a high-performance rotating electric machine can be stably manufactured. This is a useful tool that ensures the safety of assembly work. (3) The working cost of the sintered magnet used as the field magnet can be reduced while maintaining good characteristics of the rotating electric machine.

[Brief description of the drawings]

FIG. 1 is a sectional view of a main part showing one embodiment of a rotating electric machine according to the present invention.

FIG. 2 is a schematic diagram of connection between a stator-side winding and a capacitor used as a power supply for magnetization in FIG. 1;

FIG. 3 is a diagram showing a relationship between a capacitor charging voltage and a magnetization rate in the present invention.

FIG. 4 is a diagram showing a relationship between a capacitor charging voltage and a magnetization rate in a comparative example.

FIG. 5 is a sectional view of a main part showing another embodiment of a rotor incorporated in the present invention.

FIG. 6 is a cross-sectional view of a main part showing still another embodiment of a rotor incorporated in the present invention.

FIG. 7 is a cross-sectional view of a main part showing still another embodiment of the rotor incorporated in the present invention.

FIG. 8 is a diagram showing the relationship between the strength of a magnetizing magnetic field and the magnetizing rate in magnetizing a single magnet.

FIG. 9 is a diagram illustrating an initial magnetization curve.

FIG. 10 is a diagram showing the relationship between the strength of the effective magnetic field and the magnetization rate.

FIG. 11 is a perspective view showing a conventional rotor.

FIG. 12 is a sectional view of a main part showing a conventional rotating electric machine.

[Explanation of symbols]

1 magnet for field, 1a, 71a, 81a, 91a end face, 1b, 71b, 81b, 91b
72, 82, 92 Rotor core (iron core), 3, 74, 8
4,94 spaces, 4 air gaps, 5,73,83,
93 rotating shaft, 10 rotating electric machine, 21 capacitor, 5
0, 70, 80, 90 rotor, 71 arc-shaped magnet, 81
Block magnet, 91 section U-shaped magnet, 101 rotating shaft, 102 rotor core, 103 field magnet, 104
Stator, 105 rotor, 106 air gap, 108
Recess, 109, 109U, 109V, 109W teeth,
110 stator core, 115 U-phase winding, 116 V-phase winding, 117 W-phase winding, 200 rotating electric machine.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Takashi Sasaki 5200 Mikajiri, Kumagaya-shi, Saitama Magnetic Materials Research Laboratory, Hitachi Metals, Ltd.

Claims (6)

[Claims] An R-Fe-B magnet (R) is provided inside a rotor core.
Is one or two of rare earth elements such as Nd and Dy including Y
And a permanent magnet field type rotating electric machine provided with an internal magnet type rotor having a permeance coefficient (Pcm) and a residual magnetic flux density (Br) of the R-Fe-B magnet in a state of the rotor alone. : KG)
Satisfies the following relationship: (Pcm + 1)> Br / 7. A stator having a plurality of stator magnetic poles and a winding for generating a rotating magnetic field in the stator magnetic pole; a rotating shaft and a rotating shaft provided on the rotating shaft and opposed to the stator magnetic pole; At the same time, there is an R-Fe-B magnet (R is one or two or more rare earth elements such as Nd and Dy including Y) inside the rotor core and a space at the end of the R-Fe-B magnet. And a control circuit for detecting a magnetic pole position of the rotor facing the stator magnetic pole and supplying a current to the winding according to the position, and Permeance coefficient (Pcm) and residual magnetic flux density (Br: kG) of the R-Fe-B magnet in the state
Satisfies the following relationship: (Pcm + 1)> Br / 7. 3. A permanent magnet field type rotating electric machine having an internal magnet type rotor having a sintered magnet inside a rotor core, wherein the surface of the sintered magnet has a raw black scale portion. A permanent magnet field type rotating electric machine, wherein a black skin portion is arranged to face a space provided inside the rotor core. 4. The rotor core is formed using one or more of silicon steel, magnetic stainless steel, soft iron, permalloy, amorphous soft magnetic alloy, and nanocrystalline soft magnetic alloy. The permanent magnet field type rotating electric machine according to any one of claims 1 to 3, characterized in that: 5. The rotor core according to claim 1, wherein a minimum thickness of the rotor core between the field magnet and an outer peripheral surface of the rotor core is 0.5 to 5 mm. A permanent magnet field type rotating electric machine as described in the above. 6. A stator having a plurality of stator magnetic poles, a stator having a winding for generating a rotating magnetic field at the stator magnetic poles, a rotating shaft and a rotating shaft provided to rotate opposite to the stator magnetic poles. And an internal magnet type rotor having an R-Fe-B magnet (R is one or two or more rare earth elements such as Nd and Dy including Y) inside the rotor core, and facing the stator magnetic pole. And a control circuit for detecting a magnetic pole position of the rotor and supplying a current to the winding according to the detected position. After the rotor is configured so that the permeance coefficient (Pcm) and the residual magnetic flux density (Br: kG) of the Fe-B magnet satisfy the relationship of (Pcm + 1)> Br / 7, the rotor is air-gapped. And placed opposite to the stator via A method of manufacturing a permanent magnet field type rotating electric machine, comprising: constructing a permanent magnet field type rotating electric machine, and thereafter magnetizing the R-Fe-B magnet with a magnetic field generated by energizing the winding. .