JP2005051941A - Split stator core - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To offer a split core which can prevent a deterioration in iron loss property due to compressive stress, relating to a split stator core which is equipped with split yokes being demarcated by parting planes dividing an annulus ring circumferentially and whose annular yoke is constituted by coupling the split yokes with one another. <P>SOLUTION: Cuts are formed at the parting planes of split yokes CY0 and CY1, whereby projection parts C0R and C1L in the shape of projections are made. Then, the projection parts C0R and C1L are abutted on each other, whereby a gap GP1 is made in a main magnetic flux region BM. Hereby, the compressive stress in the main magnetic flux region BM can be zeroed, so this stator core can suppress the occurrence of iron loss due to the compressive stress in the main magnetic flux region BM, thus it becomes possible to elevate the efficiency of a motor. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a split stator core, and in particular, by compressing a split stator core in an annular shape to localize the compressive stress in the non-magnetic flux region where no magnetic flux exists, thereby reducing the iron loss of the stator core in the magnetic flux region. It is related with the division | segmentation stator core which can reduce.

  2. Description of the Related Art In recent years, a permanent magnet type synchronous motor having a stator core formed by a divided stator core as a constituent element has been used in hybrid vehicles and the like. Furthermore, higher performance such as higher efficiency and smaller size is required.

As a conventional technique, a technique disclosed in Patent Document 1 will be described with reference to FIG. FIG. 17 is a view showing a split stator core C101 of the prior art, in which a stress relaxation hole H101 is provided, and a conductive wire is wound around the tooth portion CT101. Then, as shown in FIG. 18, the divided stator cores C100 to C111 are joined so as to form an annular shape, and are accommodated in the core case CC by shrinking to form the stator core ST. Here, there is a problem that the iron loss increases due to the compressive stress generated in the divided stator cores C100 to C111 during shrinkage and the output efficiency of the motor decreases. However, by providing stress relaxation holes H100 to H111 in the split stator cores C100 to C111, the compressive stress applied to each split stator core during shrink shrinking is concentrated around the stress relaxation holes H100 to H111. Reduction in output efficiency can be prevented by reducing the loss. Patent Documents 2 and 3 also disclose related techniques.
JP 2002-136003 (paragraphs 0051-0052, FIGS. 10, 11) JP 2000-134732 A Japanese Patent Laid-Open No. 4-325846

  According to the above-described conventional technique, the split surfaces A101 and A102 of the split yoke core CY101 of the split stator core C101 with the other split stator core have a planar shape and are in contact with the entire yoke side surface. Therefore, compressive stress is generated in the entire divided yoke portion CY101 including the main magnetic flux region BM (shaded portion). Although the compressive stress is concentrated in the vicinity of the stress relaxation hole H101 by the stress relaxation hole H101, the remaining stress is applied to the main magnetic flux region BM. Therefore, iron loss remains in the main magnetic flux region BM where the magnetic flux always exists when the motor is operated, which is a problem because the efficiency of the motor cannot be improved. Further, in the conventional structure having only one stress relaxation hole H101 at the center of the divided yoke portion CY101, a compressive stress remains at a part away from the stress relaxation hole H101 (for example, in the vicinity of the divided surfaces A101 and A102), and iron loss also occurs. Since it remains, the efficiency of the motor is reduced, which is a problem.

  The present invention has been made to solve at least one of the problems of the prior art, and provides a split stator core capable of improving output efficiency by reducing stress generated during shrink-fitting of the split stator core. The purpose is to do.

  In order to achieve the above object, the split stator core according to claim 1 includes a split yoke portion defined by split surfaces that divide the circumferential direction of the ring, and the split yoke portions are connected to each other to thereby form an annular yoke. In the divided stator core constituting the portion, at least one of the connecting portions of the divided yoke portion includes a notch portion having an end surface that is recessed from the dividing surface in the annular inner diameter direction and a dividing surface in the annular outer diameter direction. And a protrusion having an end face.

  In the split stator core according to claim 1, when forming the annular yoke portion, the projections contact each other or between the projection portion and the split surface. A gap is formed in the region, and no compression pressure is applied to the gap. As a result, iron loss due to compressive stress in the main magnetic flux region can be reduced, and the efficiency of the motor can be increased. This also makes it possible to suppress changes in iron loss in the main magnetic flux region due to variations in machining dimensional accuracy and variations in compressive stress due to expansion / contraction due to temperature changes. In addition, by supplying a stator core having iron loss characteristics with a certain quality, and suppressing a change in iron loss due to a temperature change, it is possible to create a stator core whose efficiency is unlikely to change even if a temperature change occurs.

  The split stator core according to claim 2 is characterized in that the protrusion includes the outermost peripheral surface of the split yoke portion.

  As a result, when the annular yoke portion is formed in the connecting portion of the split yoke portion, since the protrusion is provided on the outermost peripheral portion of the ring, it is possible to sufficiently secure the main magnetic flux region having a gap on the inner diameter side of the ring. it can. Here, it is preferable that the dividing surface is constituted by a surface including the annular axis of the annular yoke portion, and thereby, when the divided stator core is connected by the dividing surface to form the annular yoke portion, a uniform stress is generated. be able to.

  The split stator core according to claim 4 is characterized in that the retreat distance from the split surface of the notch portion is longer in the inner diameter than the outer diameter side of the split yoke portion.

  As a result, the stress distribution generated in the protrusion when the divided stator cores are connected by the dividing surface can be made to be a stress distribution in which the stress in the annular inner diameter direction in the protrusion is lower. Therefore, the iron loss can be reduced even in a high load state of the motor in which the magnetic flux region is formed on the outer diameter side.

  The split stator core according to claim 5 further includes a first gap portion that divides the protruding portion, and the first gap portion has at least a part of the first gap portion on the outer diameter side of the inner diameter side end portion of the protruding portion. It exists in position.

  The split stator core according to claim 6 includes a tooth portion and a first gap portion that divides the protrusion portion, and the first gap portion includes a protrusion-side end portion at a joint portion between the split yoke portion and the tooth portion, and A first path in which the inner diameter side end portion of the projection portion is connected by a straight line, a joint center portion in a joint portion between the split yoke portion and the teeth portion, and a second portion in which the outer diameter side end portion of the projection portion is connected by a straight line. It is characterized by including at least a part of a region surrounded by a route.

  As a result, the magnetic resistance toward the protrusion is increased by the first gap, so that the magnetic flux flows through a path having a notch having a lower magnetic resistance than the path to the protrusion. That is, since the magnetic flux flows through a path where no compressive stress is applied, the occurrence of iron loss can be suppressed. Further, since the magnetic path length can be shortened as compared with the magnetic path length when the magnetic flux flows through the protrusion, the occurrence of iron loss can be suppressed.

  According to a seventh aspect of the present invention, there is provided the divided stator core according to the seventh aspect, wherein the divided stator core includes a divided yoke portion partitioned by a divided surface dividing the circumferential direction of the ring, and the divided yoke portions are connected to each other to form an annular yoke portion. The split yoke portion includes a stress receiving portion defined by a plurality of second gap portions along the annular circumferential direction, and the center line direction of the stress receiving portion in a plane perpendicular to the annular axis of the annular yoke portion And the radial direction of the annular yoke portion has a different direction.

  In the split stator core according to the seventh aspect, since the stress receiving portion has a stress receiving portion in which the center line direction and the center point direction of the ring are different, the compressive stress at the time of forming the annular yoke portion is received as a bending stress.

  Thereby, since the compressive stress can be absorbed by the stress receiving portion, the stress generated in the magnetic flux region can be reduced, and the iron loss due to the compressive stress can be reduced. In addition, this makes it possible to suppress variations in compressive stress due to variations in processing dimensional accuracy and expansion / contraction due to temperature changes. It is possible to supply a motor having the iron loss characteristics of In addition, it is possible to suppress a change in iron loss value due to a temperature change, and it is possible to create a motor in which the efficiency does not easily change even if a temperature change occurs.

  Further, in the split stator core according to claim 8, in the split stator core according to claim 7, at least a part of the second gap is opened in a slit shape with a predetermined angle with respect to the center direction of the annular yoke portion. It is characterized by a void. The split stator core according to claim 9 is the split stator core according to claim 7, wherein the second gap portion has a predetermined circumferential length for each of a plurality of circumferences having different distances from the annular axis of the annular yoke portion. It is characterized by having a slit shape.

  Thereby, since the compressive stress can be absorbed by the stress receiving portion partitioned by the second gap portion, it is possible to reduce the stress generated in the divided yoke portion and reduce the iron loss due to the compressive stress. I can do it.

  The split stator core according to claim 10 is the split stator core according to any one of claims 1 to 4, wherein at the part of the split yoke portion, at least a part is formed on the inner diameter side beyond the end portion on the inner diameter side of the protrusion. It comprises a part. Moreover, it is preferable that a 3rd space | gap part is comprised in the center part of the cyclic | annular circumferential direction in a division | segmentation yoke part.

  As a result, since the outer peripheral side is compressively deformed from the inner diameter side end of the third gap with the inner diameter side end of the third gap as a fulcrum, tensile stress is applied to the inner circumference, so Iron loss characteristics can be improved. In addition, since almost no magnetic flux is formed in the region near the outer peripheral surface of the divided yoke portion and in the vicinity of the center portion in the annular circumferential direction, if the third gap portion is formed in this region, the magnetoresistance due to the formation of the gap portion is reduced. You can avoid being affected.

  The split stator core according to claim 12 is the split stator core according to any one of claims 1 to 11, wherein the split stator core includes a tooth portion joined to the split yoke portion, and is a connecting portion of the split yoke portion. It has the structure where a teeth part is divided | segmented.

  In the split stator core according to the twelfth aspect, since the gap is formed in the center line of the tooth portion, the gap does not cross the magnetic path. Thereby, since the increase in the magnetic resistance of the divided stator core can be suppressed, problems such as a decrease in motor torque accompanying a decrease in the amount of magnetic flux can be prevented.

  According to the present invention, in the split stator core that includes the split yoke portion that is partitioned by the split surface that splits the circumferential direction of the annular ring, and the split yoke portions are connected to each other, the ring stator portion is formed in the vicinity of the protrusion. Therefore, it is possible to create a split stator core in which the compressive stress is localized only and the compressive stress in the main magnetic flux region BM is reduced. Therefore, a highly efficient motor with reduced iron loss can be created. In addition, it is possible to suppress variations in compressive stress due to expansion / shrinkage due to variations in machining dimensional accuracy and temperature changes, so that division with reduced individual loss variations in iron loss values and changes in iron loss values due to temperature changes A stator core can be created.

  DESCRIPTION OF EMBODIMENTS Hereinafter, an embodiment in which a divided stator core according to the present invention is embodied will be described in detail based on FIGS. 1 to 16 with reference to the drawings.

  A first embodiment will be described with reference to FIGS. FIG. 1 shows a part of the stator core ST of the present invention. The divided stator core C1 includes a divided yoke part CY1 and a tooth part CT1. A conductive wire is wound around the tooth portion CT1 to form a coil (not shown). The split surfaces of the split yoke portions CY0 and CY1 are surfaces including an annular shaft SO (the annular shaft SO is the same as the central axis of the stator core ST) of an annular yoke portion configured by connecting the split yoke portions to each other. The plane is defined as a split plane constituting plane RR1. Then, by forming a cutout portion on the dividing surface of the divided yoke portions CY0 and CY1, the protruding portions C0R and CIL having a protruding shape are formed. The protrusions C0R and C1L are in contact with each other without a gap, so that the gap part GP1 is formed. Further, the notches are formed on the inner peripheral side of the stator core ST on the yoke body dividing surface, so that the protrusions C1L and C0R are formed on the outermost periphery of the stator core.

  The divided stator core C1 is connected to a divided stator core C0, C2, C3... Cn (not shown) having the same structure and a predetermined number of divided stator cores so as to form an annular shape via a protrusion, and then a core case. It is stored in the CC by shrinkage. As a result, each of the divided stator cores C0 to Cn is fixed and held in a state where the projections C0R to CnR and C0L to CnL are in contact with each other, thereby forming a stator core ST. At this time, the gap portion GP1 is formed by connecting the divided stator core C1 and the divided stator core C0, and the gap portion GP2 is formed by connecting the divided stator core C1 and the divided stator core C2. Similarly, gap portions GPn are formed at the connecting portions between the divided stator cores C (n−1) and the divided stator cores Cn, so that gap portions are formed at the connecting portions of all the divided stator cores.

  The stress distribution generated in each divided stator core when the stator core ST is formed by shrinking each divided stator core into the core case CC will be described. In the split stator core C101 of the prior art shown in FIG. 17, at the joint between the tooth portion CT101 and the split yoke portion CY101, the end on the split surface A101 side is set as the origin R0, and the yoke position reference line passing through the center point of the stress relaxation hole H101. R is defined. When the width of the joint surface between the divided yoke portion CY101 and the tooth portion CT101 is 2L, the point of the distance L from the origin R0 on the yoke position reference line R is R (L), and the yoke position reference line R and the stress relaxation hole H101 are The intersections with the end portions are respectively defined as R (L + A) and R (L + C), and the intersection between the yoke position reference line R and the outer periphery of the divided yoke portion is defined as a yoke end point R (S). In the divided stator core C1 of the present invention shown in FIG. 1, the origin R0 on the yoke position reference line R, the point R (L) at a distance L from the origin R0, and the yoke end point R (S) are also defined.

  A magnetic flux region passing through the region from the origin R0 to the point R (L) at the distance L is called a main magnetic flux region BM (FIG. 1, FIG. 17 shaded region). The main magnetic flux region BM is a region in which the magnetic flux mainly passes through the split stator core during a normal load during the motor operation period. A magnetic flux region passing through the region from the point R (L) to the yoke end point R (S) is referred to as a high load magnetic flux region HA. The high-load magnetic flux region HA is a region where the amount of magnetic flux increases to generate a large torque at the time of high load during the motor operation period, and the magnetic flux is formed by protruding from the main magnetic flux region BM. Here, when the motor is at a high load, for example, when the motor is used as a power source of an automobile, the time of departure or sudden acceleration may be mentioned.

  FIG. 2 shows the stress distribution on the yoke position reference line R. In the conventional line J100 (dotted line in FIG. 2), the compressive stress is zero in the region where the stress relaxation hole H101 exists (the region from R (L + A) to R (L + C)), but the main magnetic flux region BM (R0). To R (L)), compressive stress remains. On the other hand, in the line J1 (solid line in FIG. 2) indicating the first embodiment, the compressive stress in the region from the origin R0 including the main magnetic flux region BM to the boundary point R (G) becomes zero, and from the boundary point R (G). The compressive stress in the region up to the yoke end point R (S) is concentrated higher than that in the prior art.

  Here, the boundary point R (G) is a point indicating a boundary between a region where no stress is applied and a region where the stress is concentrated. In the first embodiment of the present invention, the boundary line point R (G) is formed in contact with the contact surface between the projections C0R and C1L and the contact surface between the projections C1R and C2L. Therefore, since the gap portions GP1 and GP2 are formed in the region including the main magnetic flux region BM on the split surface of the split yoke portion CY1, the compressive stress is concentrated only in the vicinity of the protruding portion, and the compressive stress is generated in the main magnetic flux region BM. It is because it does not. On the other hand, in the prior art, the split surfaces A101 and A102 are configured by the entire side surface of the split yoke portion CY101, and the region including the main magnetic flux region BM is also in contact, so that compressive stress remains in the main magnetic flux region BM.

  Therefore, in the first embodiment, it is possible to localize the compressive stress in the region from the boundary point R (G) to the yoke end point R (S) in the high load magnetic flux region HA. That is, the compressive stress received by the split yoke portion CY101 of the first embodiment is moved from the boundary point R (G) to the outer peripheral side by the compressive stress received by the split yoke portion CY101 of the prior art. (Area of the region S1 in the graph of FIG. 2). The compressive stress received at this time is equivalent (the areas of the region S0 and the region S1 in the graph of FIG. 2 are equivalent).

  Accordingly, in the first embodiment of the present invention, the compressive stress received by the divided yoke portion is localized from the boundary point R (G) to the outer peripheral side, so that the compressive stress in the main magnetic flux region BM can be made zero. The occurrence of iron loss due to compressive stress in the main magnetic flux region BM can be suppressed, and the efficiency of the motor can be increased. That is, in a motor usage mode in which the time ratio used in light load is high, the magnetic flux flows in the main magnetic flux region BM in the stator core during most of the time when the motor is used. Further, the iron loss characteristic of the stator core is greatly deteriorated at a portion where the compressive stress is applied. From the above, since it is possible to suppress the generation of compressive stress in the main magnetic flux region BM and suppress the deterioration of the iron loss characteristic, the efficiency of the motor can be increased.

  This also makes it possible to suppress the generation / increase of compressive stress in the main magnetic flux region BM due to variations in processing dimensional accuracy and variations in compressive stress due to expansion / contraction due to temperature changes. Therefore, the individual difference variation amount of the iron loss value of the stator core can be suppressed, and it becomes possible to supply a divided stator core having a constant quality. In addition, it is possible to suppress a change in iron loss value due to a temperature change, and it is possible to create a motor in which the efficiency does not easily change even if a temperature change occurs.

  In the first embodiment shown in FIG. 2, the compressive stress in the region from the boundary line point R (G) of the high load magnetic flux region HA to the yoke end point R (S) is higher than in the prior art, and the iron loss characteristic is deteriorated. . However, in a motor usage mode in which the magnetic flux flows in the main magnetic flux region BM during most of the time when the motor is used, the time during which the magnetic flux flows in the region from the boundary line point R (G) to the yoke end point R (S). Since the ratio is sufficiently small, the effect of increasing the motor efficiency by improving the iron loss characteristic in the main magnetic flux region BM is sufficiently larger than the effect of reducing the motor efficiency by deteriorating the iron loss characteristic in this region. Therefore, high efficiency of the motor can be achieved.

  Here, as a usage form of a motor having a high time ratio used in a light load, for example, a motor is used as a prime mover of a hybrid vehicle. In a hybrid vehicle that is driven by gasoline during constant speed travel (a high percentage of travel time), the motor also rotates and magnetic flux is induced during constant speed travel. It is formed in the magnetic flux region. Therefore, if the iron loss in the main magnetic flux region is reduced, the heat generation of the motor can be suppressed. In addition, by moving the area where compressive stress is localized depending on the size and position of the protrusion to the outer diameter side from the high load magnetic flux area HA, iron loss is reduced in all areas from light load to high load. It is possible to make it.

  If the gap value G of the gap portions GP1 to GPn is too wide, the magnetic permeability decreases due to the influence of air, and as a result, the magnetic resistance of the gap portion increases. Further, it is necessary to set a gap value G so that the gap portions do not contact each other when thermal expansion or the like occurs in the stator core. As such a gap value G, for example, a value of 40 to 50 (μm) may be used for the gap portions GP1 to GPn.

  In the split yoke portion CY1 of the split stator core C1 according to the first embodiment of the present invention, the protrusions C1L and C1R are formed by forming notches on the left and right split surfaces, but the split yoke portion CY1. The structure which has a notch part only in any one of these division surfaces may be sufficient. For example, the left divided surface of the divided yoke portion CY1 has a protrusion C1L (having a cutout portion), and the right divided surface has a divided surface (having no cutout portion) constituted by the divided surface constituting surface RR2. The structure provided may be sufficient.

  A second embodiment will be described with reference to FIGS. FIG. 3 is a view showing a split stator core C1S having a magnetic block slit. The split stator core C1S includes magnetic block slits S1L and S1R in the vicinity of the protrusions C1L and C1R, respectively. Each of the magnetic block slits S1L and S1R has a rectangular shape having a short side length M1 and a long side length M2, and the short side length M1 is sufficiently larger than the gap value G of the gap portions GP1 and GP2. Has a value. For example, when the gap value G is 40 to 50 (μm), the short side length M1 of the magnetic block slit has a value of 300 to 400 (μm). Further, since the structure other than the point provided with the magnetic block slit is the same as that of the split stator core C1 of the first embodiment, detailed description thereof is omitted here. The magnetic block slits S1L and S1R are examples of the first gap.

  A position where the magnetic block slit is formed will be described. In FIG. 3, when the inner diameter side end of the protrusion C1L is defined as CA1T, a region existing on the outer diameter side from the inner diameter side end CA1T is defined as CAA. The magnetic block slits S1L and S1R are configured so that a part of the outer diameter side area CAA is included. In addition, in the joint portion between the divided yoke portion CY1S and the tooth portion CT1S, the end portion on the protruding portion C1L side is defined as CYL, and a straight line connecting the end portion CYL and the inner diameter side end portion CA1T is defined as a path BB1. Further, when the outer diameter side end portion of the protrusion C1L is defined as CA1G and the joint center portion at the joint portion between the split yoke portion CY1S and the tooth portion CT1S is defined as CYC, the outer diameter side end portion CA1G and the joint center portion CYC. A straight line connecting the two is defined as a route BB2. Then, the magnetic block slits S1L and S1R are configured so that a part thereof is included in an area surrounded by the path BB1 and the path BB2.

  FIG. 4 will be described. In the divided stator core C1 (left figure in FIG. 4) of the first embodiment, the magnetic path of the magnetic flux B0 is compressed when the magnetic resistances of the divided yoke part dividing surfaces CA1 and CA2 are smaller than the magnetic resistances of the gap parts GP1 and GP2. It is formed in the core joints CA1 and CA2 which are stressed regions. On the other hand, in the split stator core C1S of the second embodiment (the right diagram in FIG. 4), the magnetic resistance of the magnetic path toward the core joints CA1 and CA2 is increased by the magnetic block slits S1L and S1R. Are formed in the gap portions GP1 and GP2 having a relatively lower magnetic resistance than the core junction portion.

  Here, the iron loss characteristic generally deteriorates when compressive stress is applied to the magnetic path and when the magnetic path becomes longer. Therefore, since the magnetic path of the magnetic flux B0 is formed in the core joints CA1 and CA2 to which compressive stress is applied, the iron loss characteristic is deteriorated, but the magnetic path of the magnetic flux BS is formed in the gap portions GP1 and GP2 where no compressive stress is applied. Therefore, iron loss can be reduced. In addition, since the magnetic path length of the magnetic flux BS can be shortened compared to the magnetic path length of the magnetic flux B0, iron loss can be reduced. Therefore, by providing the magnetic block slits S1L and S1R as described above, the output efficiency of the motor can be improved by reducing the iron loss. The magnetic resistance increased by providing the gap portions GP1 and GP2 is negligible because it is sufficiently smaller than other magnetic resistances (such as the magnetic resistance existing due to the gap value between the rotor and the stator).

  A third embodiment will be described with reference to FIGS. FIG. 5 is a view showing a split stator core C1P having stress relaxation slits. The stress relaxation slit is an example of the second gap portion. The divided stator core C1P includes a stress relaxation portion SPA including a number of stress relaxation slits SP in the vicinity of the outer peripheral surface of the divided yoke portion CY1P. Further, since the structure other than the point provided with the stress relaxation part SPA is the same as that of the divided stator core C1 of the first embodiment, detailed description thereof is omitted here. FIG. 6 is an explanatory diagram of the stress relaxation part SPA. T-shaped stress relaxation slits SP1, SP2,... SPn are arranged in combination in opposite directions. Here, paying attention to the stress receiving portion BR1 (shaded portion in FIG. 6) formed so as to separate the adjacent stress relaxing slits SP1 and SP2, a center line separating the stress relaxing slits SP1 and SP2 in the stress receiving portion BR1. Consider the center lines CL1A to CL1C of the stress receiving portion BR1. The center direction PP of the annular stator core ST is indicated by an arrow.

  A case where the divided stator core is housed in the core case CC by shrinkage and the compression stress PC due to tightening is applied to the divided stator core C1P will be described with reference to FIG. The compressive stress PC is directed in the central direction PP. At this time, since the center line CL1B of the stress receiving portion BR1 and the center direction PP coincide with each other, a compressive stress acts in the direction of the center line CL1B on the portion constituted by the center line CL1B of the stress receiving portion BR1. Similarly, a compressive stress also acts in the direction of the center line CL1C at the site formed by the center line CL1C. On the other hand, since the direction of the center line CL1A and the direction of the center direction PP do not coincide with each other, a bending stress acts on a portion of the stress receiving portion BR1 constituted by the center line CL1A and deforms as shown by portion A in FIG. . Here, the amount of deformation due to the compressive stress at the portion constituted by the center lines CL1B and CL1C of the stress receiving portion BR1 and the amount of deformation due to the bending stress at the portion constituted by the center line CL1A are larger in the latter. Therefore, if a part of the stress receiving part BR1 has a structure part in which the center line and the central direction PP of the stress receiving part BR1 are different, it becomes possible to use deformation due to bending stress, and compressive stress with a small elastic coefficient. Since it can receive, compressive stress can fully be absorbed.

  FIG. 8 is a graph showing the correlation between the tightening pressure CN and the shrinkage allowance YB. The tightening pressure CN is a tightening pressure received by the stator core ST from the core case CC. The shrinkage allowance YB is a value having a relationship of “(shrinkage allowance YB) = (stator core ST outer diameter) − (core case CC inner diameter)”. The origin of “shrinkage allowance YB = 0” is that the inner diameter of the core case CC and the outer diameter of the stator core ST exactly match. Since the outer diameter of the stator core ST becomes larger than the inner diameter of the core case CC as the shrinkage allowance YB increases, the pressure for tightening the stator core ST during shrinkage increases, and the tightening pressure CN generated in the split stator core also increases. Further, the necessary holding tightening pressure CN0 in FIG. 8 is a minimum necessary tightening pressure that the divided stator core receives in order to obtain a fixing strength that does not cause a practical problem when the divided stator core is fastened and fixed by the core case CC. is there. The shrink shrink margin amount YBM is designed so that it does not fall below the minimum required tightening force even when the tightening force of the stator core ST is reduced most due to tolerances at the time of molding the divided stator core or volume changes due to temperature changes. Is a shrinkage allowance added as an offset to the shrinkage allowance value (YBO1, YBO2 in FIG. 8). When the stator core is actually created, shrinkage allowance values (YB1 and YB2 in FIG. 8) obtained by adding the shrinkage margin amount YBM to the shrinkage allowance value by design are used. The margin pressures CNM1 and CNM2 are tightening pressures that increase from the necessary pressing tightening pressure CN0 by taking the shrink shrink margin amount YBM.

  As shown in the correlation diagram between the shrinkage allowance YB and the tightening pressure CN in FIG. 8, the slope of the graph of the split stator core of the prior art (dotted line in FIG. 8) is that of the split stator core of the third embodiment (solid line in FIG. 8). Larger than the slope of the graph. This is because the split stator core of the third embodiment includes the stress relaxation portion SPA, so that it is possible to use deformation due to bending stress, and to receive and absorb compressive stress generated by tightening pressure with a small elastic coefficient. Because. Therefore, when the stator core is formed using the shrinkage allowance YB1 (conventional technology) and the shrinkage allowance YB2 (third embodiment), the fastening pressures are the fastening pressures CN1 and CN2, respectively, and the relationship CN1> CN2 is established. Thereby, since the split stator core of the third embodiment includes the stress relaxation portion SPA, it is possible to reduce the compressive stress generated in the magnetic flux region, and to reduce the iron loss.

  The tightening pressure values that change when the shrinkage allowance varies within the shrinkage margin amount YBM range are CNM1 (conventional technology) and CNM2 (third embodiment), respectively, and the relationship of CNM1> CNM2 is established. This is because the split stator core according to the third embodiment includes the stress relaxation portion SPA, so that deformation due to bending stress can be used, and compressive stress can be received with a small elastic coefficient and sufficiently absorbed. .

  As a result, it is possible to suppress variations in processing stress and variations in compressive stress due to expansion / contraction due to temperature changes. It becomes possible to supply. In addition, it is possible to suppress a change in the iron loss value due to a temperature change, and it is possible to create a split stator core in which the efficiency does not easily change even if the temperature changes.

  Moreover, as shown in FIGS. 9 and 10, various shapes can be mentioned as the shape of the stress relaxation slit. The split stator core C1Q in FIG. 9 includes a stress relaxation portion SQA including a number of stress relaxation slits SQ1 to SQn in the vicinity of the outer peripheral surface of the split yoke portion CY1Q. The stress relaxation slits SQ1 to SQn are gaps having a predetermined angle with respect to the central direction PP to the annular axis SO of the annular yoke portion and opened in a slit shape on the outer peripheral surface of the divided yoke portion CY1Q. Here, focusing on the center line CLQ (n−1) of the stress receiving portion BRQ (n−1) (shaded portion in FIG. 9) formed so as to separate the stress relaxation slits SQ (n−1) and SQn, The line CLQ (n−1) has a certain angle with respect to the central direction PP. Therefore, since the stress receiving portion BRQ (n−1) can use deformation due to bending stress, it can receive the compressive stress with a small elastic coefficient, and therefore can sufficiently absorb the compressive stress.

  Further, the divided stator core C1U of FIG. 10 includes a stress relaxation portion SUA including a number of stress relaxation slits SU in the vicinity of the outer peripheral surface of the divided yoke portion CY1U. The stress relaxation slit SU is opened in a slit shape with a predetermined length along the circumferences RU1 to RU3 having different distances from the annular axis SO of the annular yoke portion. Since the stress relaxation portion SUA has many shapes similar to those of the stress receiving portion BR1 shown in FIG. 6, it is possible to utilize deformation due to bending stress and to receive compressive stress with a small elastic coefficient. Can be absorbed sufficiently.

  A fourth embodiment will be described with reference to FIGS. FIG. 11 is a diagram showing a split stator core C1W having a tension applying slit. The tension applying slit is an example of the third gap portion. The divided stator core C1W includes a tension applying portion SGA including a plurality of tension applying slits SG1 to SG3 at an outer peripheral end portion of the divided yoke portion CY1W. Since the structure other than the point provided with the tension applying portion is the same as that of the split stator core C1 of the first embodiment, detailed description thereof is omitted here. The position where the tension applying slit is formed will be described. When the inner diameter side end of the protrusion C1L is defined as CA1T in FIG. 11, the tension applying slits SG1 to SG3 are configured so that a part thereof is included on the inner diameter side of the inner diameter side end CA1T. The tension applying slit SG2 is formed on the arc center line YC of the outer peripheral surface of the divided yoke portion CY1W.

  FIG. 12 will be described. When the compressive stress PC from the core case CC is applied to the split stator core C1W, the compressive stress is concentrated on the split yoke portion split surfaces CA1 and CA2, and the tension applying slits SG1 to SG3 are deformed. At this time, the slits SG1 to SG3 are deformed in such a manner that the slit opening SGO is narrowed and the slit bottom SGB is not deformed. At this time, with the slit bottom SGB as a fulcrum, the outer peripheral side of the slit bottom SGB is compressively deformed, so that tensile stress is applied to the inner peripheral side of the slit bottom SGB. That is, the outer peripheral portion of the divided yoke portion CY1W is subjected to compressive stress T1, while the boundary line LC that passes through the slit bottom SGB and is concentric with the core case CC is used as the boundary line, and the tensile stress T2 is applied to the inner peripheral portion of the divided yoke portion CY1W. Take it.

  FIG. 11 shows the yoke position reference line R, and FIG. 13 shows the stress distribution on the yoke position reference line R. On the reference line R, the positions of the tension applying slits SG1 to SG3 are defined as slit position points R (T). In the line J1 (dotted line in FIG. 8) showing the first embodiment, the stress is zero in the region from the origin R0 to the slit position point R (T), whereas the line J4 (solid line in FIG. 13) showing the fourth embodiment. In FIG. 2, the tensile stress increases as the slit position point R (T) approaches the origin R0. The iron loss depends on the stress, and the iron loss increases at the portion where the compressive stress acts, but decreases at the portion where the tensile stress acts. Therefore, the iron loss characteristics improve as the slit position point R (T) approaches the origin R0. In addition, the amount of magnetic flux and the amount of torque generated by the motor are substantially proportional to each other. When the load is light (when the low torque is generated), the magnetic flux flows near the origin R0, and the amount of magnetic flux increases as the load increases. L) Considering the swelling to the side, it can be seen that the invention of the fourth embodiment improves the iron loss characteristics particularly at light loads. In addition, the case where a motor is used as a motor | power_engine of a hybrid vehicle as mentioned above is mentioned as a motor with a high use ratio at the time of a light load.

  Thus, the slit position point R (T) that is the inner diameter side end of the tension applying portion SGA is used as a fulcrum, and the outer peripheral side of the slit position point R (T) is compressed and deformed. Since stress is applied, the iron loss characteristics of the region can be improved. Also, since almost no magnetic flux is formed in the region near the outer peripheral surface of the divided yoke portion CY1W and in the vicinity of the center portion in the annular circumferential direction (arc centerline YC), if the tension applying portion SGA is formed in this region, It is possible to avoid the influence of the magnetoresistance due to the formation of the magnetic flux, and to prevent a decrease in the amount of magnetic flux.

  In FIG. 12, since the tensile stress T2 is applied to the inner peripheral portion of the divided yoke portion CY1W, it is necessary to consider that the gap portions GP1 and GP2 are set slightly wider. Further, the number and shape of the tension applying slits are not limited to the form of the fourth embodiment, and for example, a form provided on the entire outer peripheral part of the divided yoke part CY1W may be used.

  A fifth embodiment will be described with reference to FIGS. FIG. 14 is a view showing a split stator core C1T provided with a protruding portion having a tapered shape. Protruding portions C1LT and C1RT are provided on the left and right divided surfaces of the divided yoke portion CY1T of the divided stator core C1T, respectively. Further, since the structure other than the point provided with the protrusions C1LT and C1RT is the same as that of the split stator core C1 of the first embodiment, detailed description thereof is omitted here. The protrusion C1LT has a tapered shape in which the retraction amount of the annular yoke portion from the split surface constituting surface RR1 passing through the annular axis SO is continuously larger on the inner diameter side than the outer diameter side of the split yoke portion CY1T. Yes. FIG. 15 shows the stress distribution on the yoke position reference line R when the divided stator core C1T is connected. From FIG. 15, the yoke end point R (S) is more in line J5 (solid line in FIG. 15) indicating the stress distribution in the fifth embodiment than in line J1 (dotted line in FIG. 15) indicating the stress distribution in the first embodiment. It can be seen that compressive stress is concentrated on the side.

  Thereby, in the divided stator core ST formed by connecting the divided yoke portions, the iron loss can be further reduced. In other words, by moving the compressive stress from the high load magnetic flux region to the outer diameter side (the yoke end R (S) side with respect to the main magnetic flux region BM), the iron loss in a wider region from light load to high load is achieved. Can be reduced. For example, in FIG. 15, the stress distribution line J5 of the fifth embodiment can further reduce the iron loss on the inner diameter side (the origin R0 side) compared to the stress distribution line J1 of the first embodiment. Note that the protrusion C1LT is not limited to a tapered shape. For example, the retraction amount from the split surface constituting surface RR1 may have a staircase shape that increases stepwise on the inner diameter side of the split yoke portion CY1T.

  A sixth embodiment will be described with reference to FIG. The split stator core C1D shown in FIG. 16 is characterized in that the split surface of the split yoke portion is constituted by a surface including the center lines TL1 and TL2 of the teeth portion and the axis of the stator core. The divided stator core C1D includes a divided yoke part CY1D, a tooth part CT1L, and a tooth part CT1R. And the notch part is formed in the division surface of teeth part CT0R and CT1L, and protrusion part C0RD and C1LD which have protrusion shape are formed. Then, the protrusion part C0RD and C1LD are in contact with each other without a gap, so that the gap part GP1D is formed. Further, since the other structure is the same as that of the divided stator core of the first to fourth embodiments, detailed description thereof is omitted here. In the split stator core C1 of the first embodiment (FIG. 1), there is a magnetic resistance because the gap portions GP1 and GP2 exist so as to cross the magnetic path. On the other hand, in the split stator core C1D (FIG. 16) of the sixth embodiment, the gap portions GP1D and GP2D are formed on the center lines TL1 and TL2 of the tooth portions, so the gap portions do not cross the magnetic path of the magnetic flux BD.

  Thereby, the increase in the magnetic resistance of the divided stator core C1D can be suppressed. Therefore, since the fall of the magnetic flux amount of magnetic flux BD can be suppressed, problems, such as a fall of the torque of the motor accompanying the magnetic flux amount fall, can be prevented.

  The divided stator core of the present invention is not limited to that of the above-described embodiment, and various modifications can be made without departing from the spirit thereof. For example, the inventions of the first to sixth embodiments can be implemented in an appropriate combination. Like the divided stator core C1D shown in FIG. 16, the magnetic block slits S1L and S1R, the stress relaxation portion SPA, and the tension applying portion. It is possible to configure SGA together.

It is a figure which shows the structure of the division | segmentation stator core in 1st Embodiment. It is a figure which shows the stress distribution of the division | segmentation stator core in 1st Embodiment. It is a figure which shows the structure of the division | segmentation stator core in 2nd Embodiment. It is a figure which shows the magnetic flux which flows into the division | segmentation stator core in 2nd Embodiment. It is a figure which shows the structure of the division | segmentation stator core in 3rd Embodiment. It is a figure which shows the structure of the stress relaxation part in 3rd Embodiment. It is a figure which shows the mode at the time of a deformation | transformation of the stress relaxation part in 3rd Embodiment. It is a figure showing the correlation with the compressive stress of a split stator core and shrinkage allowance in 3rd Embodiment. It is a figure which shows the 1st example of the division | segmentation stator core in 3rd Embodiment. It is a figure which shows the 2nd example of the division | segmentation stator core in 3rd Embodiment. It is a figure which shows the structure of the division | segmentation stator core in 4th Embodiment. It is a figure which shows the stress which generate | occur | produces in the division | segmentation stator core in 4th Embodiment. It is a figure which shows the stress distribution of the division | segmentation stator core in 4th Embodiment. It is a figure which shows the structure of the division | segmentation stator core in 5th Embodiment. It is a figure which shows the stress distribution of the division | segmentation stator core in 5th Embodiment. It is a figure which shows the structure of the division | segmentation stator core in 6th Embodiment. It is a figure which shows the structure of the division | segmentation stator core in a prior art. It is a figure which shows the structure of the stator core in a prior art.

Explanation of symbols

ST Stator core C1 Split stator core CY1 Split yoke portion CT1 Teeth portion RR1 Split surface configuration surface C0R, CIL Protrusion CC Core case GP1, GP2 Gap portion R Yoke position reference line BM Main magnetic flux region HA High load magnetic flux region S1L, S1R Magnetic block Slit SPA for stress relief

Claims (12)

In a divided stator core that includes a divided yoke portion that is divided by a dividing surface that divides the circumferential direction of the ring, and that forms the annular yoke portion by connecting the divided yoke portions to each other,
At least one of the connecting portions of the split yoke portion has a notch portion having an end surface that is recessed from the split surface in the annular inner diameter direction;
A split stator core comprising: a projecting portion having the split surface as an end surface in an annular outer diameter direction.   The split stator core according to claim 1, wherein the protruding portion includes an outermost peripheral surface of the split yoke portion.   The split stator core according to claim 1, wherein the split surface is constituted by a surface including an annular axis of the annular yoke portion.   4. The structure according to claim 1, wherein a retreat distance of the cutout portion from the dividing surface is longer at an inner diameter than an outer diameter side of the divided yoke portion. Split stator core. Comprising a first gap that partitions the protrusion,
5. The first gap portion according to claim 1, wherein at least a part of the first gap portion is present at a position closer to an outer diameter side than an inner diameter side end portion of the protruding portion. The split stator core described in 1. A tooth portion, and a first gap portion that divides the protruding portion,
The first gap is
A first path that connects the protruding portion side end portion of the joint portion between the divided yoke portion and the teeth portion and an inner diameter side end portion of the protruding portion in a straight line;
A second path that connects a joint center portion of the joint portion between the split yoke portion and the tooth portion and an outer diameter side end portion of the projection portion in a straight line;
5. The split stator core according to claim 1, wherein the divided stator core includes at least a part of a region surrounded by the structure. In a divided stator core that includes a divided yoke portion that is divided by a dividing surface that divides the circumferential direction of the ring, and that forms the annular yoke portion by connecting the divided yoke portions to each other,
The divided yoke portion includes a stress receiving portion partitioned by a plurality of second gap portions along the annular circumferential direction,
2. A split stator core having a direction in which a center line direction of the stress receiving portion and a radial direction of the annular yoke portion are different in a plane perpendicular to the annular axis of the annular yoke portion.   8. The split stator core according to claim 7, wherein at least a part of the second gap portion is a gap having a predetermined angle with respect to a central direction of the annular yoke portion and opened in a slit shape. 9.   The said 2nd space | gap part has a predetermined | prescribed circumference length for every several circumferences from which the distance from the annular axis of the said annular yoke part differs, It is comprised by slit shape, It is characterized by the above-mentioned. The split stator core described in 1.   The said division | segmentation yoke part is equipped with the 3rd space | gap part by which at least one part is formed in the internal diameter side beyond the internal diameter side edge part of the said projection part, The any one of Claim 1 thru | or 4 characterized by the above-mentioned. Split stator core.   11. The split stator core according to claim 10, wherein the third gap portion is configured at a center portion in an annular circumferential direction of the split yoke portion. The split stator core includes a tooth portion joined to the split yoke portion,
12. The split stator core according to claim 1, wherein the tooth portion is divided at a connecting portion of the split yoke portion. 13.

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