JP2008035618A - Exciter and synchronous machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce an eddy current to enhance efficiency in an exciter whose yoke and teeth are constituted of electromagnetic steel plates laminated in different directions. <P>SOLUTION: This rotary exciter includes the split yoke 1 and the teeth 2. The direction of a normal line to each steel plate face of the laminated electromagnetic steel plate constituting the yoke is identical with the direction of the rotating shaft of the exciter. The direction of the normal line to each steel plate face of the laminated electromagnetic steel plate constituting the teeth is identical with the direction of the circumference of the exciter. Insulating portions 6, 26 are formed in proximity to joints between the yoke and the teeth to reduce eddy currents (EC4), EC3 in the electromagnetic steel plate faces generated in the yoke or the teeth. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an exciter that generates a moving magnetic field by passing an electric current and a synchronous machine using the exciter, and more particularly to a structure of an exciter in a synchronous machine such as an electric motor or a generator.

  2. Description of the Related Art Conventionally, for example, a permanent magnet synchronous machine rotates a rotor by the action of a magnetic field generated by passing a current through a stator (stator) and a magnetic field generated by a permanent magnet embedded in a rotor (rotor). Such an electromagnetic force is generated, and it is widely used as an electric motor that is excellent in maintainability, controllability and environmental resistance, and can be operated with high efficiency and high power factor regardless of the industrial or consumer electronics field. ing.

  Here, it is a synchronous motor that causes electric energy to flow through the synchronous machine to obtain a rotational driving force, and conversely, a synchronous generator that rotates the synchronous machine to extract electric energy from the synchronous machine. In this specification, a synchronous machine including both of them is used. Since both structures are basically the same, a synchronous motor will be mainly described in detail as an example. In this specification, the exciter is mainly described as a stator. However, for example, the exciter can be configured as a rotor by passing a current through the rotor.

  Furthermore, the exciter is the same regardless of whether it is a synchronous machine, an induction machine or a DC machine, and it goes without saying that the present invention can be applied to such equipment.

  1 and 2 show an example of a conventional synchronous machine, FIG. 1 is a cross-sectional view, and FIG. 2 is a vertical cross-sectional view. 1 and 2, reference numeral 1 is a yoke, 2 is a tooth, 7 is a stator, 8 is a rotor, and 9 is a permanent magnet.

  As shown in FIGS. 1 and 2, in the conventional synchronous machine, a rotor 8 is arranged inside a stator 7 constituted by a yoke 1 and teeth 2. For example, a permanent magnet 9 is embedded in the rotor 8, and the rotor 8 is rotated by a magnetic field generated by flowing a three-phase alternating current through the stator 7 acting on the permanent magnet 9.

  Conventionally, a stator of a synchronous machine has been made by laminating non-oriented electrical steel sheets (NO) in order to reduce iron loss. Here, the non-oriented electrical steel sheet is a steel sheet having a uniform relative permeability in any direction on the surface of the steel sheet, and is widely used as a material having relatively small iron loss, but operates continuously for a long time. As a material used for the stator of the synchronous machine, further improvement in magnetic properties is required.

  Conventionally, the yoke 1 and the teeth 2 of the stator 7 are divided, and a directional electromagnetic steel sheet (GO) whose circumferential direction is the direction of easy magnetization is used for the yoke 1, and the radial direction is used for the teeth 2. It is also known to reduce iron loss by using a grain-oriented electrical steel sheet having an easy magnetization direction.

  However, in the conventional synchronous machine shown in FIG. 1 and FIG. 2, the flow direction of magnetic flux from the yoke 1 to the tooth 2 is not smooth because the direction of lamination of the directional electromagnetic steel sheets constituting the yoke 1 and the tooth 2 is the same direction. A rotating magnetic field having a large magnetic resistance is generated in this portion, and the iron loss is increased. Further, since the magnetic flux passing through the stator 7 passes through both the boundary line between the divided yokes 1 and the boundary line between the yoke 1 and the teeth 2, there is a problem that iron loss increases due to the magnetic resistance of the boundary line. there were.

  Therefore, conventionally, in order to improve the performance by reducing the overall magnetic resistance in the stator, a stator is formed by connecting a tooth portion to which a coil is attached and a yoke portion, and a grain-oriented electrical steel sheet is formed on the tooth portion. An electric motor that uses a magnetic material with low magnetic permeability anisotropy for the yoke portion has been proposed (see, for example, Patent Document 1).

  Conventionally, a plurality of stators each having a yoke and teeth are stacked and fixed in the thickness direction, the yoke is divided in the circumferential direction, and the boundary between the divided yokes in the circumferential direction where the teeth are provided. There is also provided a synchronous machine in which the yoke and teeth are made of a directional electromagnetic steel sheet, the direction of easy magnetization of the yoke is the circumferential direction of the stator, and the direction of easy magnetization of the teeth is the radial direction of the stator (for example, , See Patent Document 2).

  Further, in order to reduce the magnetic resistance and iron loss of the exciter (stator) in which the yoke is divided in the circumferential direction and increase the magnetic flux (B), the directionality in which the yoke and the teeth are stacked in different directions is used. An exciter composed of an electromagnetic steel plate and a synchronous machine using the exciter have also been proposed (for example, refer to Patent Document 3; hereinafter referred to as an orthogonal motor).

  Conventionally, there is also published a document that clarifies the rotating magnetic field generated at the connecting portion between the yoke and teeth of the motor and the magnetic characteristics of the rotating magnetic field by a two-dimensional vector magnetic characteristic measuring device (for example, Patent Document 4). And 5).

  By the way, the electromagnetic field analysis technique by the finite element method is known conventionally, and is described in various documents (for example, refer nonpatent literature 1 and 2). The finite element method divides electric devices such as motors into spatially small meshes and calculates Maxwell's equations numerically, assuming that the inside of the mesh can be expressed by a low-order function. The condition that minimizes is formulated as an actual physical quantity. It is used to clarify electromagnetic characteristics such as motor loss and electromagnetic torque, and can accurately reflect actual phenomena. In addition, the literature regarding the iron loss used for the evaluation of the magnetic characteristic of an electromagnetic steel sheet is also issued conventionally (for example, refer nonpatent literature 3).

Japanese Unexamined Patent Publication No. 2000-078780 JP 2004-056906 A JP 2004-236495 A JP 2004-347482 A JP 2005-069933 A K. Fujisaki, S. Satoh, "Numerical Calculations of Electromagnetic Fields in Silicon Steel Under Mechanical Stress", IEEE Transactions on Magnetics, Volume: 40, Issue: 4, July 2004, Pages: 1820-1825 Nakata, Takahashi "Electrical Engineering Finite Element Method 2nd Edition" Morikita Publishing Co., Ltd., 1986, Tokyo Nippon Steel Co., Ltd. “Electrical Steel Sheets Illustrated”, Nippon Steel Co., Ltd., 1985

  As described above, the electric motor disclosed in Patent Document 1 uses a directional electromagnetic steel plate in the teeth portion, and a magnetic material having a low magnetic permeability anisotropy in the yoke portion (low carbon steel steel plate or non-oriented electrical steel plate). However, since the magnetic material having a small magnetic permeability anisotropy is also used at the joint between the yoke 1 and the tooth 2, the flow of magnetic flux from the yoke 1 to the tooth 2 is not smooth. There is a problem that a rotating magnetic field having a large magnetic resistance is generated in the portion and iron loss is increased.

  In the stator disclosed in Patent Document 2, the yoke and the teeth are made of directional electromagnetic steel sheets, the easy magnetization direction of the yoke is the circumferential direction of the stator, and the easy magnetization direction of the teeth is the radial direction of the stator. However, as in Patent Document 1, since the lamination direction of the yoke and the tooth is not orthogonal, eddy current does not occur, but there is a problem that a rotating magnetic field is generated and iron loss is increased.

  FIG. 3 is a cross-sectional view showing a part of an exciter (stator) in another example (orthogonal motor) of a conventional synchronous machine disclosed in Patent Document 3.

  In FIG. 3, reference numeral 3 indicates a boundary line between the yoke and the yoke, and 4 indicates a boundary line between the yoke and the tooth. Here, the direction of lamination of the directional electromagnetic steel sheets of the yoke 1 and the teeth 2 is such that the normal direction of the steel sheet surface of the yoke 1 is the rotational axis direction of the motor and the normal direction of the steel sheet surface of the teeth 2 is the circumferential direction. .

  A conventional stator 7 shown in FIG. 3 includes a yoke 1 and a tooth 2 at an outer peripheral portion, the yoke 1 and the tooth 2 are circumferentially arranged around the rotor, and the yoke 1 is divided in the circumferential direction of the stator. . The yoke 1 and the teeth 2 are configured by stacking directional electromagnetic steel sheets in different directions. Thereby, generation | occurrence | production of the rotating magnetic field of the stator with which the yoke is divided | segmented into the circumferential direction can be suppressed, magnetic resistance and iron loss can be reduced, and magnetic flux density (B) can be increased.

FIG. 11 is a diagram for explaining a rotating magnetic field.
As shown in FIG. 11, for example, when the magnetic steel sheet is AC-excited, the rotating magnetic field has a one-cycle locus of the magnetic flux density vector B (Bx, By) in a two-dimensional plane at a certain position in the magnetic steel sheet. It occurs in an elliptical shape and occurs frequently at the connecting portion of the motor yoke and teeth (see Patent Document 4 for details).

  In addition, the magnetic characteristics of the rotating magnetic field can be clarified by a two-dimensional vector magnetic characteristic measuring device (see Patent Document 5). Is desired.

  Note that, in alternating current excitation of a bulk-shaped magnetic material instead of an electromagnetic steel plate, the rotating magnetic field sometimes refers to a case where the one-cycle locus of the magnetic flux density vector deviates from the two-dimensional plane.

  In the stator disclosed in Patent Document 3, the stacking direction of the yoke and the teeth is orthogonal, and there is no coplanar surface at the joint between the yoke and the tooth, and the stator rotates around the boundary 4 between the yoke and the tooth. It becomes difficult to generate a magnetic field. However, although the exciter having the structure can reduce the rotating magnetic field, there is a problem that the loss increases because the stacking direction of the yoke and the teeth is orthogonal.

  In view of the problems of the above-described conventional exciter (synchronous machine), the present invention provides an exciter composed of electromagnetic steel plates in which yokes and teeth are laminated in different directions, while suppressing the generation of a rotating magnetic field. The purpose is to reduce the loss and increase the efficiency.

  According to the present invention, the normal direction of each steel sheet surface of the laminated electromagnetic steel sheets constituting the yoke is provided with divided yokes and teeth, and is the rotational axis direction of the exciter and constitutes the teeth. The normal direction of each steel sheet surface of the laminated electromagnetic steel sheets is a rotary exciter that is the circumferential direction of the exciter, and an insulating part is provided in the vicinity of the joint between the yoke and the tooth, An exciter is provided that reduces eddy currents generated in the yoke or the teeth.

  Here, it is preferable that the teeth are fitted so as to leave the outer peripheral portion of the yoke, the insulating portion is provided on the outer peripheral portion of the yoke in the vicinity of the tooth tip portion, and the outer peripheral portion of the yoke at the tooth tip portion. To reduce eddy currents. Further preferably, the insulating portion is provided over the entire width of the electromagnetic steel sheet constituting the yoke. The insulating portion is provided on at least one side in the thickness direction (rotational axis direction) of the yoke in the vicinity of the tip of the teeth, and has a width of 1/3 or more of the thickness from the end surface of the yoke. You may comprise as follows.

  In another form of the exciter according to the present invention, the insulating portion is only on the yoke side to which the teeth are joined, or on the yoke side in a direction penetrating the laminated electromagnetic steel plates in the side surface portion of the teeth. In addition, the eddy current generated in the teeth is reduced by being provided on the rotating shaft side of the exciter. Here, it is preferable that the insulating portion has a width of 1/3 to 1/4 of the width of the side surface portion of the tooth.

According to another aspect of the exciter of the present invention, an insulating portion is provided at a joint between the yoke and the tooth to reduce eddy current generated in the yoke or the tooth.
And the synchronous machine provided with the exciter of the said invention is also provided by this invention.

  According to the present invention, in an exciter composed of magnetic steel sheets in which a yoke and a tooth are laminated in different directions, an eddy current can be generated by providing an insulating portion at a portion of the yoke and the tooth where a large eddy current is generated during AC excitation. Since generation | occurrence | production can be suppressed, the loss of a stator can be reduced and it can be made highly efficient.

  Embodiments of an exciter and a synchronous machine according to the present invention will be described below in detail with reference to the accompanying drawings.

  First, with respect to the stator shown in FIG. 3, a detailed study was made on the mechanism of occurrence of loss when AC excitation was performed. Here, the normal direction of the steel plate surface of the yoke 1 is the rotational axis direction of the motor, and the normal direction of the steel plate surface of the teeth 2 is the circumferential direction of the motor. The examination results will be described below.

  FIG. 4 is an enlarged perspective view showing the stator shown in FIG. In the stator of FIG. 4, the eddy current EC3 is generated in the teeth 2 and the eddy current EC4 is generated in the yoke 1 in the surface of the electromagnetic steel sheet to reduce the motor efficiency. It turned out to be.

  The details will be described with reference to FIGS. 9, 10 and 13 of analysis results obtained by using the finite element method for the electromagnetic field analysis model relating to the exciter shown in FIG.

In FIG. 12, only the three teeth 20 and the accompanying yoke 10 that are the basis of the concentrated winding stator core are taken up, and a plurality of teeth are expressed by using periodic boundary conditions in the horizontal (X-axis) direction. Yes. The portion 80 corresponding to the rotor is assumed to be solid iron (conductivity is zero) for convenience.
The table in FIG. 12 shows analysis conditions such as physical property values of the electrical steel sheet. The difference in the stacking direction between the yoke and the teeth is expressed by the relative permeability anisotropy. The exciting current was 50 Hz with a three-phase alternating current. In addition, half the thickness is considered in the Z-axis direction, and a symmetrical boundary condition is set. Furthermore, the electrical conductivity of the steel material is expressed by a tensor that makes the electrical conductivity in the stacking direction zero, and expresses an eddy current flowing in the steel material portion in the plane direction of the steel material.

  FIG. 9 shows the magnetic flux density distribution, eddy current vector distribution (→ distribution) and loss (iron loss) in each condition by the electromagnetic field analysis of the finite element method in order to clarify the electromagnetic phenomenon in the stator structure of FIG. It is a figure which shows ratio of (+ eddy current).

  In FIG. 9, the loss (iron loss + eddy current) described in the lower column is expressed as a ratio of each loss (W / kg) when the total loss (W / kg) is 1. First, for comparison, (1) NO (non-oriented electrical steel sheet) integrated was also analyzed for loss by the finite element method. Further, a two-shape analysis was performed in which the yoke and teeth were both composed of GO (directional magnetic steel sheet) as the stator structure, and the joint between the yoke and the teeth was insulated (2) and conductive (3). In the case (2) and the case (3), the lamination direction of the electromagnetic steel sheets is the rotation axis direction at the yoke and the rotation direction at the teeth. Note that it is considered that the actual joint between the yoke and the tooth is between the insulation and the conduction.

  In this analysis, as the iron core loss, not only the conventional iron loss (calculated from the BW characteristic) but also the iron core structure is represented by the tensor expression of the electrical resistivity in consideration of the stacking direction. The influence of the eddy current flowing in the plane of the iron core electrical steel sheet is also taken into consideration.

  That is, in FIG. 9, the iron loss (conventional iron loss) is a loss measured from the hysteresis curve of the magnetic steel sheet obtained by the SST (Single Sheet Tester) or EPSTEIN method usually used for evaluating the magnetic properties of the magnetic steel sheet. It is composed of hysteresis loss obtained at the time of direct current excitation, eddy current loss induced by flowing in the thickness direction of the steel plate at the time of alternating current, and abnormal eddy current loss due to domain wall movement (see Non-Patent Document 3 for details). That is, the eddy current loss in the iron loss here is an eddy current flowing in the thickness direction of the steel sheet.

  On the other hand, the planar eddy current, which is another loss, refers to an eddy current flowing in the plane of the electromagnetic steel sheet, and is a phenomenon that does not appear when measuring the magnetic properties of the steel sheet, such as SST. This planar eddy current is manifested in the configuration of a three-dimensional iron core such as a motor and an exciting current. In other words, depending on the relative position of the iron core and the excitation current, connection conditions, etc., the magnetic flux density appears perpendicular to the planar steel sheet surface, and by trying to satisfy the continuity of the eddy current, It is a flowing eddy current. In FIG. 9 and the following description, the planar eddy current is simply referred to as “eddy current”.

  As shown in the loss (iron loss + vortex loss) column in the lower part of FIG. 9, when the case (2) in which the joint portion between the yoke and the tooth is insulated, the vortex is compared with the case (1) integrated with NO. It can be seen that the loss of current increases. This is presumably because the magnetic flux density is concentrated on the yoke side (see the area CA in FIG. 9) of the tooth tip, and the eddy current in that portion is increased.

  In addition, looking at the case (3) in which the joint between the yoke and the tooth is electrically conductive, it can be seen that the loss due to the eddy current is increased as compared with the case (1) integrated with NO. This is considered to be because an eddy current straddling the yoke-tooth flows inside the yoke (see the region CB in FIG. 9) because the yoke and the tooth are conductive.

  FIG. 10 is a diagram showing a detailed distribution of the eddy current vector (arrow) at the excitation current phase ωt = 315 degrees under the condition of the case (3). Since the yoke and the tooth are electrically connected, it can be seen that the eddy current induced on the side surface of the tooth flows along the surface of the yoke to the adjacent yoke portion.

  It is considered that the actual joint portion between the yoke and the tooth is between insulation and conduction. The detailed analysis of the electromagnetic phenomenon in which the eddy current flows in each component of the stator illustrated in FIGS. 9 and 10 shows that the loss due to the eddy current (plane eddy current) generated in the plane of the electromagnetic steel sheet is When it comprised, the knowledge that it became very large in case (2) and case (3) compared with case (1) was acquired. Based on this knowledge, as a loss reduction measure in the stator structure of FIG. 4, the present invention has been achieved in which an eddy current is reduced by disposing an insulating portion at a predetermined portion of a yoke and a tooth as described below. .

  FIG. 5 is a perspective view showing a part of an embodiment of a stator in an exciter (synchronous machine) according to the present invention. In FIG. 5, reference numeral 6 indicates an insulating portion between the yokes.

  As shown in FIG. 5, in the stator 7 of the present embodiment, the normal direction of the steel plate surface of the yoke 1 is the rotational axis direction of the motor, and the normal direction of the steel plate surface of the teeth 2 is the circumferential direction of the motor. It is said that.

  As can be seen from a comparison between FIG. 5 and FIG. 4 described above, the stator 7 in the present embodiment is configured so that the eddy current (EC3 described with reference to FIG. 4) generated in the side surface portion of the tooth 2 is converted into the eddy current. The loss is reduced by providing the insulating portion 26 in the path of EC3, while reducing the loss by providing the insulating portion 6 in the path of the eddy current EC4 generated in the yoke 1. Note that the thickness of the insulating portion is preferably within the range where the insulating property can be secured, from the viewpoint of not increasing the magnetic resistance.

  First, the insulating portion of the teeth will be described. 6 and 7 are views for explaining in more detail the shape of the insulating portion 26 in the stator shown in FIG. 5, FIG. 6 is a side view seen from the direction DD in FIG. 5, and FIG. 5 is a perspective view seen from the direction of EE in FIG.

  As the insulating portion 26 provided on the side surface portion 2a of the tooth 2, for example, as shown in FIG. 6A, insulating portions 261 and 262 are provided on both sides near the center of the tooth 2, or as shown in FIG. In this way, the insulating portion 261 is provided on one side near the center of the tooth 2, or a plurality of insulating portions 263a to 263d are provided on both sides of the tooth 2 as shown in FIG. As shown in d), an insulating portion 264 is provided around the center of the tooth 2. Thereby, the eddy current EC3 which arises in the side part 2a of the teeth 2 can be reduced.

  6A to 6C, the width W7 of the insulating portion 261 (262, 263a to 263d) is, for example, about 1/3 to 1/4 of the width W6 of the side surface of the tooth 2. If it is a width, the eddy current EC3 can be sufficiently reduced.

  Further, as shown in FIG. 7, the planar shape (the shape seen from the direction of EE in FIG. 5) of the insulating portion 26 on the yoke 1 side provided in the tooth 2 is, for example, a connecting line 4 between the yoke 1 and the tooth 2. However, the present invention is not limited to this, and other shapes (for example, the insulating portion 26b) may be used. Furthermore, although the planar shape of the rotor-side insulating portion 26 provided in the teeth 2 is, for example, a rectangular shape, it is needless to say that other shapes may be used. In any case, any shape that prevents the path of the eddy current EC3 generated in the tooth 2 may be used.

  Note that the thickness (depth) W9 of the insulating portion 26a (26b, 26c, 26, 261, 262, 263a to 263d, 264) is, for example, about 1 / (width) of the tooth 2 (thickness viewed from the plane) W8. If the thickness is about 3 to 1/4, the eddy current EC3 can be sufficiently reduced. Although the eddy current can be reduced even if the thickness W9 is greater than 1/3, it is disadvantageous because the magnetic resistance of the teeth slightly increases.

  On the other hand, with respect to the yoke 1, it can be seen from FIG. 10 that eddy current flows more in the thickness direction (Z-axis direction) in the range from the end portion to about a quarter at the back portion of the yoke 1.

  FIG. 14 is a view for explaining an example of the shape of the insulating portion between the yokes in the stator shown in FIG. As shown in FIG. 14, when a slit is inserted, the eddy current itself is also bypassed, so it is more effective to insert an insulating portion up to at least one third.

  When the case (2) in which the joint portion between the tooth and the yoke shown in FIG. 9 is insulated is compared with the conductive case (3), the insulated case (2) generates less eddy current. I understand. For this reason, in order to reduce the loss of the exciter (synchronous machine), it is considered effective to insulate the joint between the tooth and the yoke.

  In each of the embodiments described above, the exciter according to the present invention has been described as a stator of a rotary type synchronous machine (rotary motor). However, the exciter of the present invention is only applied as a stator of such a motor. However, the present invention can also be applied as a stator of a linear synchronous machine (for example, a linear motor). In the case of a linear type synchronous machine, the rotation direction in the above description is read as the magnetic field movement direction of the synchronous machine, and the rotation axis direction is read as the direction perpendicular to the magnetic field movement direction and the connection direction of the yoke and the teeth. In other words, the above description can be applied as it is.

  Further, for example, also in a rotary motor, the connection between the yoke 1 and the tooth 2 may be a rectangular connection line 40 as shown in FIG. 8 instead of the acute connection line 4 as shown in FIG. Good. That is, the exciter of the present invention includes a yoke 1 and a tooth in various exciters including a yoke 1 composed of electromagnetic steel plates laminated in the rotation axis direction and a tooth 2 composed of electromagnetic steel plates laminated in the rotation direction. The eddy current can be reduced by providing an insulating portion in the path of the eddy current generated in the vicinity of the connection line.

  Here, as a member constituting the insulating portion, for example, paper, mica tape, a resin sheet, a resin tape, or the like, or a variety of conventionally known insulators such as filling with an insulating resin is used. Is possible. Further, as the thickness (T1, T2) of the insulating portion, for example, the generation of eddy current can be sufficiently reduced even in the range of about 10 μm to 100 μm within a range where dielectric breakdown does not occur.

  Further, by applying the exciter (stator) of the present invention to a synchronous machine (such as an electric motor or a generator), it is possible to provide a highly efficient synchronous machine with little loss.

  Furthermore, the laminated electrical steel sheets constituting the yoke 1 and the teeth 2 are not limited to directional electrical steel sheets, and an eddy current reduction effect can be obtained even in the case of non-oriented electrical steel sheets.

  The present invention can be applied to various exciters including yokes and teeth composed of electromagnetic steel plates laminated in different directions, and a synchronous machine using the exciter. Therefore, the present invention makes it possible to manufacture a high-efficiency synchronous machine, and is a technology that can be used greatly in the industry.

It is a cross-sectional view showing an example of a conventional synchronous machine. It is a longitudinal cross-sectional view which shows an example of the conventional synchronous machine. It is sectional drawing which shows a part of stator in the other example of the conventional synchronous machine. It is a perspective view which expands and shows the stator shown in FIG. It is a perspective view which shows a part of one Example of the stator which concerns on this invention. FIG. 6 is a view (No. 1) for explaining the shape of an insulating portion in the stator shown in FIG. 5. FIG. 6 is a diagram (No. 2) for explaining the shape of an insulating portion in the stator shown in FIG. 5. It is sectional drawing which shows the further example of application of the stator which concerns on this invention. It is a figure which shows the ratio of magnetic flux density distribution, eddy current vector distribution, and loss (iron loss + eddy current) in each condition by the electromagnetic field analysis of a finite element method. Eddy current vector distribution in the half of the yoke thickness when conducting to the junction between the yoke and the teeth by electromagnetic field analysis of the finite element method (condition of case (3), one tooth: ωt = 315 degrees). It is a figure for demonstrating a rotating magnetic field. It is a figure (including a physical property value) for demonstrating the model which performed the electromagnetic field analysis by the finite element method. It is a figure which shows the eddy current vector distribution of the half thickness part of a yoke when it is electrically connected to the junction part of a yoke and teeth by the electromagnetic field analysis of a finite element method. It is a figure for demonstrating the example of the shape of the insulation part between the yokes in the stator shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Yoke 2 Teeth 3 Boundary line between yoke and yoke 4,40 Boundary line between yoke and tooth 5 Electromagnetic coil 6, 60, 61, 62; 16, 161, 26, 26a to 26c; 261, 262, 263a 263d, 264 Insulation part 7 Exciter (stator)
8 Rotor 9 Permanent magnet 10 Yoke (electromagnetic field analysis model)
20 teeth (electromagnetic field analysis model)
80 Parts corresponding to the rotor (electromagnetic field analysis model)
EC1 to EC4 Eddy current

Claims (10)

A normal direction of each steel sheet surface of the laminated electromagnetic steel sheets constituting the yoke, including the divided yoke and teeth, is a rotating shaft direction of an exciter, and the laminated electromagnetic steel sheets constituting the teeth The normal direction of each steel plate surface is a rotary exciter that is the circumferential direction of the exciter,
An exciter characterized in that an insulating portion is provided in the vicinity of a joint between the yoke and the tooth to reduce eddy current generated in the yoke or the tooth. In the exciter according to claim 1,
The teeth are fitted leaving the outer periphery of the yoke, the insulating portion is provided on the outer periphery of the yoke near the tip of the tooth, and the eddy current generated on the outer periphery of the yoke near the tip of the tooth is reduced. Exciter characterized by reducing. In the exciter according to claim 2,
The exciter according to claim 1, wherein the insulating portion is provided over the entire width of the electromagnetic steel sheet constituting the yoke in the vicinity of the tip of the tooth. In the exciter according to claim 2,
The insulating portion is provided on at least one side in the thickness direction of the yoke in the vicinity of the tip of the tooth, and has a width of 1/3 or more of the thickness of the yoke from the end surface of the yoke. Exciter characterized by In the exciter according to any one of claims 1 to 4,
The insulating portion is provided on a yoke side to which the teeth are joined in a direction penetrating the laminated electromagnetic steel plates in a side surface portion of the teeth, and reduces eddy current generated in the teeth. Exciter. In the exciter according to claim 5,
The exciter according to claim 1, wherein the insulating portion has a width of 1/3 to 1/4 of a width of a side surface portion of the teeth. In the exciter according to claim 5,
The insulator is provided on the side surface of the tooth and further on the rotating shaft side of the exciter to reduce eddy current generated in the tooth. The exciter according to claim 7,
The exciter according to claim 1, wherein the insulating portion has a width of 1/3 to 1/4 of a width of a side surface portion of the teeth. In the exciter according to any one of claims 1 to 8,
An exciter characterized in that an insulating portion is provided at a joint between the yoke and the tooth to reduce eddy current generated in the yoke or the tooth.   A synchronous machine comprising the exciter according to any one of claims 1 to 9.