JP4762836B2 - Exciter and synchronous machine - Google Patents

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. In addition, since both structure is fundamentally the same, in the following detailed description, it demonstrates mainly taking a synchronous motor as an example. In the present specification, the exciter is mainly described as a stator, but it is needless to say that the exciter can be configured as a rotor by passing an electric current through the rotor, for example.

  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 has been demanded.

  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 sheet and a synchronous machine using the exciter have also been proposed (see, for example, Patent Document 3).

  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.

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

  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 of a conventional synchronous machine, and shows the stator disclosed in Patent Document 3 described above.

  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, in the stator shown in FIG. 3, the lamination direction of the steel plates of the yoke 1 and the teeth 2 is a radial direction and the normal direction of the steel plate surface of the teeth 2 is a motor (rotary motor). The direction of the rotation axis.

  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 an iron loss can be reduced, and magnetic flux density (B) can be increased.

FIG. 10 is a diagram for explaining the rotating magnetic field.
As shown in FIG. 10, 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.

  4 is an enlarged perspective view of the stator shown in FIG. In FIG. 4, reference numeral 5 indicates an electromagnetic coil attached to the tooth 2.

  In FIG. 4, first, when an alternating current is applied to the electromagnetic coil 5 attached to the tooth 2 (P1), a magnetic flux density B1 is generated in the direction of the rotation axis of the electromagnetic coil 5 in the tooth 2 (P2). The magnetic flux density B1 is directed from the tooth 2 to the yoke 1, and a part (B2) of the magnetic flux density B1 reaches the joint portion 3 between the center portion of the tooth 2 and the circumferential portion of the yoke 1 (P3).

  Here, since the magnetic flux density B2 is an alternating current component, an eddy current EC1 is generated at the tip of the tooth 2 in the outer peripheral portion 1a of the yoke 1 so as to go around the vector of the magnetic flux density B2. Further, an eddy current EC2 is generated between two adjacent teeth 2 in the inner peripheral portion 1b of the yoke 1. As described above, when the eddy currents EC1 and EC2 flow through the steel plate of the yoke 1, the loss increases and becomes a major impediment to the high efficiency of the motor.

  In the present invention, in view of the problems of the above-described conventional exciter (synchronous machine), the normal direction of each steel sheet surface of the laminated grain-oriented electrical steel sheets constituting the yoke is the radial direction of the exciter, and In the rotary exciter where the normal direction of each steel sheet surface of the laminated grain-oriented electrical steel sheets constituting the teeth is the direction of the rotation axis of the exciter, loss is minimized as much as possible while suppressing the generation of a rotating magnetic field. The purpose is to reduce the efficiency.

According to the first aspect of the present invention, the normal direction of each steel sheet surface of the laminated grain-oriented electrical steel sheets comprising the yoke and the teeth that are divided, and the radial direction of the exciter, The normal direction of each steel sheet surface of the laminated grain-oriented electrical steel sheets constituting the teeth is a rotating exciter that is the rotating shaft direction of the exciter, and is a joint between the yoke and the teeth. An insulating portion is provided in the vicinity so as to reduce eddy current generated in the yoke or the teeth, and the insulating portion is formed between the first tooth and the second tooth adjacent to the first tooth. An exciter is provided that includes a first insulating portion provided in the vicinity of a joint portion with the first tooth at an inner peripheral portion of the yoke, and reduces eddy current generated in the yoke. .

According to the second aspect of the present invention, the normal direction of each steel sheet surface of the laminated grain-oriented electrical steel sheets comprising the yoke and teeth divided, and the yoke is the radial direction of the exciter, The normal direction of each steel sheet surface of the laminated grain-oriented electrical steel sheets constituting the teeth is a rotating exciter that is the rotating shaft direction of the exciter, and is a joint between the yoke and the teeth. An insulating portion is provided in the vicinity so as to reduce eddy current generated in the yoke or the teeth, and the insulating portion is formed between the first tooth and the second tooth adjacent to the first tooth. A synchronous machine comprising a first insulating portion provided in the vicinity of a joint portion with the first tooth at an inner peripheral portion of the yoke, and an exciter for reducing eddy current generated in the yoke Is provided.

Here, preferably, the teeth, the fitted leaving an outer periphery of the yoke, the insulating portion further comprises a second insulating portion formed on the outer peripheral portion of the yoke, the outer peripheral portion of the yoke to reduce the eddy current generated in the tooth tip definitive in. The second insulating portion is provided on at least one side in the width direction of the electromagnetic steel sheet constituting the yoke, and has a width of 1/3 to 1/4 of the width of the electromagnetic steel sheet. May be.

Et al is, preferably, the first insulating portion is provided on at least one side of the yoke between the first and second teeth, and, the width of the yoke between the first and second teeth 1 It has a width of / 3 to 1/4. Further, a plurality of the first insulating portions may be provided on both sides of the yoke between the first and second teeth.

Further, the insulating portion may further include a third insulating portion provided at a joint portion between the yoke and the tooth, and may be configured to reduce eddy current generated in the yoke or the tooth.

  ADVANTAGE OF THE INVENTION According to this invention, in the exciter comprised with the electromagnetic steel plate which laminated | stacked the yoke and the teeth on the different directions, an eddy current can be reduced and high efficiency can be achieved.

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

  FIG. 5 is a cross-sectional view showing a part of an embodiment of an exciter (stator) according to the present invention, and shows a case where the exciter is applied as a stator of a rotary type synchronous machine (rotary motor). . In FIG. 5, reference numeral 1 is a yoke, 2 is a tooth, 6 is an insulating portion provided on the outer periphery of the yoke near the tip of the tooth, and 7 is a stator.

  The stator 7 of the present embodiment is applied to, for example, the rotary motor as shown in FIGS. 1 and 2 described above, and each steel plate of the laminated electrical steel sheets constituting the yoke 1 as in the stator shown in FIG. The normal direction of the surface is the radial direction of the motor, and the normal direction of each steel plate surface of the laminated electromagnetic steel plates constituting the teeth 2 is the rotation axis direction of the motor.

  As can be seen from a comparison between FIG. 5 and FIG. 4 described above, in the stator 7 of the present embodiment, the teeth 2 are fitted at the boundary line 4 leaving the outer peripheral portion 1 a of the yoke 1, and the outer peripheral portion of the yoke 1 is A slit-like insulating portion 6 is provided at the tip of the tooth 2 in 1a to reduce eddy current (EC1 described with reference to FIG. 4) generated at the tip of the tooth 2 in the outer peripheral portion 1a of the yoke 1.

  Here, as the material of the insulating portion 6, various materials conventionally used such as paper, mica tape, resin sheet, and resin tape can be applied. In addition, the thickness T1 of the insulating portion 6 is preferably thin from the viewpoint of suppressing an increase in magnetic resistance. For example, the generation of eddy currents can be sufficiently reduced as long as the dielectric breakdown does not occur even when the thickness T1 is about 10 μm to 100 μm.

  6 is a view for explaining the shape of the insulating portion in the stator shown in FIG. 5, and is a view seen from the direction of AA in FIG.

  As the insulating portion 6 provided at the tip of the tooth 2 in the outer peripheral portion 1a of the yoke 1, for example, as shown in FIG. 6A, is the insulating portion 60 configured as a whole in the width direction of the steel plate constituting the yoke 1? As shown in FIG. 6 (b), part of both sides in the width direction of the steel plate constituting the yoke 1 is configured as the insulating portions 61, 62, or as shown in FIG. 6 (c), the yoke 1 A part on one side in the width direction of the steel plate constituting the steel plate is configured as an insulating portion 61 to reduce the generation of eddy current EC1.

  6 (b) and 6 (c), the width W1 of the insulating portion 61 (62) is, for example, about 1/3 to 1/4 of the width W0 of the electromagnetic steel sheet constituting the yoke 1. If so, the eddy current EC1 can be sufficiently reduced. Since the eddy current (EC1) flows so as to suppress the generation of the magnetic flux (B2), the eddy current itself is about 1/3 of the width W0 of the electrical steel sheet when looking at the numerical analysis result using the finite element method. The outer side with a width of about 1/4 is larger and stronger, and the inner side is smaller and weaker. For this reason, in order to suppress the eddy current, it is effective to suppress the outer eddy current that is flowing strongly and strongly, so that the width is about 1/3 to 1/4 of the width W0 of the electrical steel sheet. If an insulating part is inserted, it can be said that the reduction effect is great.

  The state of eddy current generation will be described in detail based on electromagnetic field analysis results by the finite element method. The electromagnetic field analysis technique based on the finite element method is described in detail in, for example, Non-Patent Document 1 or 2, and the description thereof is omitted here.

  With respect to the stator shown in FIG. 3, detailed investigations were made on the mechanism of occurrence of loss when AC excitation was performed. First, the outline of the examination results will be described.

  FIG. 4 is an enlarged perspective view showing the stator shown in FIG. In the stator of FIG. 4, it has been found that one of the causes of increased loss in this method is that eddy currents EC1 and EC2 are generated in the yoke 1 to reduce the motor efficiency.

  FIG. 11 is a model of an electromagnetic field analysis performed by the finite element method. Here, FIG. 11 corresponds to the stator of FIG.

In FIG. 11, only the three teeth 20 and the accompanying yoke 10 which 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. . The portion 80 corresponding to the rotor is assumed to be solid iron (conductivity is zero ) for convenience.

  The table in FIG. 11 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 excitation current was 3 phase AC and 50 Hz. In addition, in the Z direction, half the thickness is considered and a symmetrical boundary condition is set. Furthermore, the electrical conductivity of the steel material represents a tensor that makes the electrical conductivity in the stacking direction zero, and represents an eddy current flowing in the steel material portion in the plane direction of the steel material. A gap of about 0.5 mm is provided between the tooth tip and the portion 80 corresponding to the rotor.

  12 is a graph showing the ratio of magnetic flux density distribution, eddy current vector distribution and loss (iron loss + eddy current) for the analytical model shown in FIG. 11 in order to clarify the electromagnetic phenomenon in the stator structure of FIG. It is.

  In FIG. 12, the loss (iron loss + eddy current) normalized by the unit mass for each of the teeth, yokes and the whole described in the lower column is as follows. The total loss (w / kg) is 1. Expressed as a ratio of loss (w / kg). For comparison, an analysis was also performed in the case of a NO-integrated stator (1) in which the lamination direction of the electromagnetic steel sheets is the rotation axis direction.

  Furthermore, when the lamination direction of the magnetic steel sheets of the yoke as the stator structure is the rotational radius direction and the lamination direction of the magnetic steel sheets of the teeth is the rotation axis direction, the joint between the yoke and the teeth is insulated (2); In the case of conducting (completely in close contact), the calculation of the two forms in (3) is also performed. Note that it is considered that the actual joint between the yoke and the tooth is between the insulation and the conduction. Further, as the iron core loss, not only the conventional iron loss (calculated from the BW characteristic) but also the influence of the eddy current flowing in the stator core is considered.

  As shown in the calculation result of “vortex loss” in the (iron loss, vortex loss) column at the bottom of FIG. 12, when the case (2) in which the joint portion between the yoke and the tooth is insulated is seen, Compared to 1), it can be seen that the loss increases by the amount of eddy current. This is presumably because the magnetic flux density is concentrated on the yoke side (see the area CA in FIG. 12) of the tooth tip, and the eddy current in that portion is increased.

  Further, when the case (3) in which the joint between the yoke and the tooth is electrically conductive is seen, it can be seen that the loss is increased by the amount of eddy current as compared with the case (1) integrated with NO. This is considered to be because the eddy current straddling the yoke-teeth flows inside the yoke because the yoke and the tooth are conductive (see the region CB in FIG. 12).

  Since the actual joint portion between the yoke and the tooth is considered to be between insulation and conduction, the electromagnetic phenomenon described with reference to FIG. Such a thing can be considered.

  That is, first, the insulating portion 6 is inserted on the yoke side (region CA in FIG. 12) of the tooth tip portion to suppress the generation of eddy current. Next, an insulating portion 16 is inserted inside the yoke to suppress the generation of eddy currents across the yoke-tooth.

  FIG. 13 is a diagram showing details of an eddy current vector distribution with half thickness (outer part of yoke: ωt = 315 degrees) by electromagnetic field analysis of the finite element method. It can be seen that the eddy current flows more in the range from the end to a quarter of the back of the yoke, but when slits are inserted as shown in FIG. 6, the eddy current itself also bypasses, It is more effective to insert the insulating portions (61, 62) to one third.

  FIG. 7 is a sectional view showing a part of another embodiment of the stator according to the present invention. In FIG. 7, the electromagnetic coil 5 is omitted in order to clearly show the insulating portion 16.

  As shown in FIG. 7, in this embodiment, not only the slit-like insulating portion 6 is provided at the tip of the tooth 2 in the outer peripheral portion 1a of the yoke 1 to reduce the eddy current EC1, but also referring to FIG. The eddy current EC2 generated between the two adjacent teeth 2 (between the teeth 21 and 22) in the inner peripheral portion 1b of the yoke 1 described is also reduced.

  That is, in the inner peripheral portion 1b of the yoke 1 between the first tooth 21 and the second tooth 22 adjacent thereto, the insulating portion 16 is provided in the vicinity of the contact portion with the first tooth 21, and the first and second The eddy current EC2 generated in the yoke between the two teeth is reduced.

  8 and 9 are views for explaining the shape of the insulating portion 16 in the stator shown in FIG. 7, FIG. 8 is a view seen from the direction of BB in FIG. 7, and FIG. 9 is a view of CC in FIG. It is the figure seen from the direction.

  As the insulating portion 16 provided in the yoke 1 between the adjacent teeth 21 and 22, for example, as shown in FIG. 8A, the insulating portions 161 are provided on both sides near the center of the yoke 1 between the adjacent teeth 21 and 22. 162, or as shown in FIG. 8 (b), an insulating portion 161 is provided on one side near the center of the yoke 1 between adjacent teeth 21, 22, or as shown in FIG. 8 (c). In addition, a plurality of insulating portions 163 a to 163 d are provided on both sides of the yoke 1 between the adjacent teeth 21 and 22. Thereby, the eddy current EC2 generated in the yoke 1 between the adjacent teeth 21 and 22 can be reduced.

  8A to 8C, the width W3 of the insulating portion 161 (162, 163a to 163d) is, for example, about 1/3 of the width W2 of the yoke 1 between the adjacent teeth 21 and 22. If the width is about ¼, the eddy current EC2 can be sufficiently reduced.

  As shown in FIG. 9, the planar shape of the insulating portion 16 provided in the yoke 1 between adjacent teeth 21 and 22 (the shape seen from the direction of CC in FIG. 7) is, for example, the yoke 1 and the teeth 2. Although the insulating portion 16a has a side parallel to the connection line 4, the other shape (for example, the insulating portion 16b) may be used. In any case, any shape that prevents the path of eddy current generated in the yoke 1 between the adjacent teeth 21 and 22 may be used. The thickness (depth) W5 of the insulating portion 16a (16b, 16, 161, 162, 163a to 163d) is, for example, about 1/3 to 1/4 of the width (thickness) W4 of the yoke 1. If so, the eddy current EC2 can be sufficiently reduced.

  When the case (2) in which the joint portion between the tooth and the yoke shown in FIG. 12 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.

  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.

  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.

  Furthermore, the laminated electrical steel sheets constituting the yoke 1 and the teeth 2 are not limited to directional electrical steel sheets, and an effect of reducing eddy current 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.

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 exciter (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 sectional drawing which shows a part of one Example of the exciter (stator) which concerns on this invention. It is a figure for demonstrating the shape of the insulation part in the stator shown in FIG. It is sectional drawing which shows a part of other Example of the stator which concerns on this invention. FIG. 8 is a diagram (No. 1) for describing a shape of an insulating portion in the stator illustrated in FIG. 7. FIG. 8 is a view (No. 2) for explaining the shape of an insulating portion in the stator shown in FIG. 7. It is a figure for demonstrating a rotating magnetic field. It is the figure of the model which performed the electromagnetic field analysis by the finite element method. It is a figure which shows the ratio of the eddy current vector distribution and loss (iron loss + eddy current) in each condition by the electromagnetic field analysis of a finite element method. It is a figure which shows the eddy current vector distribution (the outer part of a yoke: (omega) t = 315 degree | times) of the half thickness by the electromagnetic field analysis of a finite element method.

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, 16a, 16b, 161, 162, 163a to 163d Insulating portion 7 Excitation Machine (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-EC2 Eddy current

Claims (7)

The normal direction of each steel sheet surface of the laminated grain-oriented electrical steel sheets constituting the yoke, including the divided yoke and teeth, is the radial direction of the exciter, and the laminated directions constituting the teeth The normal direction of each steel sheet surface of the electrical steel sheet is a rotary exciter that is the rotation axis direction of the exciter,
An insulating part is provided in the vicinity of the joint between the yoke and the tooth to reduce eddy current generated in the yoke or the tooth ,
The insulating portion is a first insulating portion provided in the vicinity of a joint portion between the first tooth and an inner peripheral portion of the yoke between the first tooth and the second tooth adjacent to the first tooth. An exciter comprising a portion and reducing eddy current generated in the yoke . In the exciter according to claim 1,
The teeth are fitted so as to leave the outer peripheral portion of the yoke, and the insulating portion further includes a second insulating portion provided on the outer peripheral portion of the yoke in the vicinity of the tip end portion of the teeth , and the outer peripheral portion of the yoke An exciter characterized by reducing eddy current generated at the tip of the tooth. In the exciter according to claim 2,
The second insulating portion is provided on at least one side in the width direction of the electromagnetic steel sheet constituting the yoke, and has a width of 1/3 to 1/4 of the width of the electromagnetic steel sheet. Exciter. In the exciter according to claim 1 ,
The first insulating portion is provided on at least one side of the yoke between the first and second teeth, and is 1/3 to 1/4 of the width of the yoke between the first and second teeth. An exciter characterized by having a width. In the exciter according to claim 4 ,
The exciter according to claim 1, wherein a plurality of the first insulating portions are provided on both sides of the yoke between the first and second teeth. In the exciter according to any one of claims 1 to 5 ,
The exciter is characterized in that the insulating part further includes a third insulating part provided at a joint part between the yoke and the tooth, and reduces an eddy current generated in the yoke or the tooth. A synchronous machine comprising the exciter according to any one of claims 1 to 6 .