JP2008283784A - Split stator and stator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a split stator improving an occupation rate, and a stator using the split stator. <P>SOLUTION: The split stator is provided with a split core 1 having teeth 3, and a rectangular wire coil 5 wound around in a plurality of columns and layers around the split core 1. The teeth 3 has a skew shape and the rectangular wire coil crosses in a plane starting at the corner portion of <90° of the skew shape. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a split stator and a stator, and more specifically to a split stator and a stator of a motor used in an automobile or the like.

  In hybrid vehicles and electric vehicles, an electric motor is used to drive the vehicle. Since this drive motor is mounted on an automobile, not only high output and high efficiency, but also miniaturization and weight reduction are significantly required compared to other applications. For this reason, weight reduction and reduction in units of grams and millimeters are continuously performed without increasing the output, but rather increasing the output.

  In an electric motor, when a magnetic field is generated by an electric current, a coil is constituted by a winding. However, in order to achieve a high output and a more compact size, the space factor of the winding in a slot such as a stator is improved to the limit. It is required to make it. Further, in order to increase the strength of the magnetic field, the current flowing through the winding is required to be a large current. Speaking of the space factor, it exceeds 50% and approaches the theoretical maximum value.

  Under the above circumstances, the improvement of the space factor is directly linked to the higher output of the motor, the improvement of fuel consumption, etc., and the improvement is still required. For example, there has been proposed a stator in which a divided core having a shape in which the circumferential width of the teeth portion decreases along the axial direction and a divided core having a larger shape are wound after being wound adjacent to each other (Patent Document). 1). According to this structure, there is no useless space, and it is possible to prevent a case where the space factor of the winding made with respect to the slot portion of the stator is not sufficient. In addition, a configuration has been proposed in which stepped portions are formed stepwise on the side surfaces of the teeth of the split stator, and the rectangular wire of the winding is directly wound around the teeth without using an insulator (Patent Document 2). With this configuration, it is possible to reduce the number of parts and prevent winding disturbance while securing a high space factor by straight winding of a rectangular wire.

Further, as a known technique for skew-type teeth in connection with the present invention, there are the following. Proposed a structure that suppresses vibration and noise by concentrically winding coils on a plurality of skew-type teeth integrally formed on an annular yoke and inserting a winding damping body between windings of different phases (Patent Document 3). According to this, in a highly efficient concentrated winding motor, vibration and noise can be suppressed by the winding damping body inserted between the windings.
JP 2006-217702 A JP 2005-318669 A Japanese Patent Laid-Open No. 2003-32939

  However, in the stator in which the divided cores in which the circumferential width of the tooth portion is large or small along the axial direction are alternately arranged, there are the following problems. Usually, in a concentrated winding divided stator, the coil winding start and winding end are performed on either the upper surface or the lower surface to facilitate wiring. In the stator having the above structure, every other split stator surface having a narrow circumferential width appears on the upper surface or the lower surface along the circumferential direction. It is practically impossible to make a surface a cross-processed surface that moves to the next turn. As a result, aligned winding cannot be performed, and the space factor decreases. In order to avoid this, if the cross process is performed only on the surface of the divided stator having a wide circumferential width, the wiring is divided into upper and lower parts, and complicated wiring is unavoidable, resulting in an increase in the size of the stator.

  In addition, in a split stator in which a flat wire is wound directly around a tooth with a stepped step portion on the side surface of the teeth of the split stator, the teeth are tapered. Slippery. For this reason, winding disorder arises and a space factor falls. Although it is conceivable to use a holding jig or the like for preventing slipping, the productivity is lowered.

  As for a plurality of skew-shaped teeth with an annular arrangement that are integrally formed, there is a method in which a nozzle is passed through a gap and concentrated winding is performed on each tooth, but alignment winding is difficult because the lines are twisted. Moreover, although the method of inserting the coil wound beforehand can also be used, in this method, the clearance by insertion arises between a coil and teeth, and it becomes difficult to arrange in alignment. In either case, the space factor decreases. Also, the core cannot be collared.

  In the presence of the prior art as described above, there is a demand for development of a stator that is easy to manufacture and can improve the space factor. In order to meet this demand, an object of the present invention is to provide a split stator that can be easily manufactured and can improve a space factor, and a stator using the same.

  A split stator according to the present invention includes a split core having teeth, and a coil of a rectangular wire wound in a plurality of rows, a plurality of layers, and wound on the split core, the teeth are skewed, and the rectangular wire coil is skewed It is characterized by crossing on one side starting from a corner of less than 90 °.

  With the above configuration, by using a flat wire that increases the space factor but is difficult to wind, the sharp corners are used as the starting point of cross processing, thereby preventing slipping, shortening the pitch between lines, and facilitating tension alignment winding. Realizing and improving the space factor. Moreover, since it is a division | segmentation stator, the advantage that it is easy to control a wrinkle and is easy to wind can also be acquired. Furthermore, since the teeth are skew, the cogging torque of the concentrated winding divided stator can be suppressed and smoothed.

  Further, the above-mentioned split core has a brim at one end of the tooth and a back yoke at the other end of the tooth, and the teeth have both side surfaces continuously or intermittently from the back yoke side toward the brim side. Further, they can have shapes that approach each other. Here, the side surface is a surface stretched between the stator axial direction component and the stator radial direction component of the teeth, and is a surface intersecting the stator circumferential direction. With this configuration, in a structure in which a plurality of divided stators are annularly arranged with the collar side perpendicular to the stator axis and the coil axis in the radial direction with the collar side being the stator axis (center) side, the windings of adjacent divided stators are While preventing overlapping, the number of layers of the coil from the back yoke side to the flange side is made uniform, and the length of the coil in the axial direction can be shortened. In addition, since the width of the teeth on the back yoke side is increased, the magnetic flux is increased, and the outer diameter of the back yoke can be reduced.

  The flat wire coil can be formed on an insulator covering the split core. Thereby, the winding (flat wire) can be wound around the split core without paying great attention to the insulation with the split core.

  In the above insulator, the corners of the four corners are rounded corresponding to the skew shape of the split core, and the corners of the skewed portion of less than 90 ° can be made smaller than the corners of the corner portion exceeding 90 °. . Thereby, relaxation of stress concentration at the corner due to tension when winding the coil, prevention of insulation deterioration between the winding and the split core, prevention of cracking of the insulator, and the like can be realized.

  A groove for each turn for a rectangular wire can be attached to the radius of the corner portion of the insulator on the crossing surface. Thereby, in the case of a straight core (skew type), positioning in the rounded portion of the cross processing of the flat wire can be ensured. Further, in the case of a taper core (skew type), it is effective for positioning of the cross processing of the rectangular wire and prevention of slipping when the taper is rolled down.

  The groove of the insulator can be shallow along the groove width direction from the back yoke side to the flange side. Thereby, in a taper core or a stepped core, the slip at the time of taper unwinding of a flat wire can be prevented more reliably, and aligned winding becomes easy. Although the groove width direction attached to the cross-processed surface does not exactly coincide with the direction from the back yoke side to the flange side, the difference in the direction is very small. Can also be applied.

  The split core and the insulator can be integrally formed. Thereby, the assembly | attachment property of the insulator to the division | segmentation core which was attached | subjected with skew, a taper, etc. was improved, As a result, productivity can be improved.

  The stator of the present invention is a stator in which any one of the above-mentioned divided stators is arranged in a ring shape. Thereby, a small and high performance electric motor can be obtained.

  ADVANTAGE OF THE INVENTION According to this invention, it is easy to manufacture and can provide the split stator which can improve a space factor, and a stator using the same.

(Embodiment 1)
FIG. 1 is a diagram showing a split stator 10 according to Embodiment 1 of the present invention. In FIG. 1, a split stator 10 is formed by winding a split core having a flange 2 and a back yoke 4 and a hidden tooth, an insulator 6 covering the split core, and a rectangular wire 5. With a coil. The above-described split stator 10 has a skew shape and is characterized in that a rectangular wire is used for the winding. The fact that the cross process, which is another feature, is performed only on a specific surface will be described later.

FIG. 2 is a top view of the divided stator of FIG. 1 as viewed from above. 3 is a cross-sectional view taken along line III-III in FIG. As shown in FIG. 3, in the skew shape, the cross-sectional shape of the teeth 3 is a parallelogram, and accordingly, the cross-sectional shape and the two-dimensional shape of the insulator 6 and the back yoke 4 are also parallelograms. Since the coil is formed by winding the winding around a tooth having a parallelogram cross section, it naturally has a cross-sectional shape along the parallelogram. In FIG. 2, the flat wire 5 is wound around the insulator 6 that covers the teeth, but the cross process is performed only on one specific surface (the upper surface in FIG. 2). When winding a winding around a spiral coil, it is necessary to shift the winding in the direction of the spiral axis (coil axis) in parallel with the winding. Performing the shifting of the winding is called cross processing. In the present embodiment, has a characteristic cross process starting from the particular corner, to the point of performing only the cross-process surface S _c of the upper surface.

As shown in FIG. 3, in the case of the skew type, two types of internal angles are generated at the corners of the parallelogram in the cross section of the tooth 3. That is, two types of corners are produced: an acute angle (less than 90 °: angle α) and an obtuse angle (greater than 90 °: angle β). The insulator 6 that covers the teeth 3 is rounded at the corners, but the radius value R ₁ of the corners of the acute angle α reflects the radius value R of the corners of the obtuse angle β, reflecting the size of the inner angle of the teeth 3. _Less than ₂ . According to FIG. 2 and FIG. 3, the winding 5 is, starting from the corner corresponding to the acute angle alpha, i.e. starting from the corners of the insulator 6 to radius value R ₁ is attached, the cross-process surface of the upper surface S _c It is wound while crossing over. Therefore, in the corner as a starting point, the interior angle of the teeth are sharp, because Earl value R ₁ of the insulator 6 is small, 5 flat wire, made difficult to slip at the corners of its origin. This is because when the corner radius value is smaller, a larger stress (pressure) acts locally between the winding and the corner portion, and a frictional force that restrains each other is generated. Note that the cross section of the skew shape does not necessarily have to be a parallelogram, acute and obtuse corners are formed, and the divided stator is arranged along the circumference and viewed along the stator axial direction. Any shape may be used as long as it does not inconvenience the formation of the stator while partially superimposing the adjacent magnetic flux.

The flat wire 5 used in the present embodiment has a small gap between adjacent windings in a state where a coil is formed, and can improve the space factor compared to a coil having a round cross section. Winding was apt to occur and was difficult to handle. In particular, slipping easily occurred at the corners during the cross processing, and turbulence was likely to occur. However, according to the above configuration, as a starting point for cross-process corners of the acute angle of the skew-shaped, so that the upper surface only cross-process surface S _c, in terms of enhanced space factor, preventing irregular winding Can do.

  Further, since the teeth are skewed, the cogging torque of the concentrated winding divided stator can be suppressed and smoothed. That is, if the skew type is not used, a cogging torque is generated because a high-density magnetic flux distribution is clearly divided and distributed for each divided stator at the rotor position on the inner peripheral side of the adjacent divided stator. However, in the skew type, adjacent divided stators distribute magnetic fluxes while partially overlapping each other, so that cogging torque can be suppressed and smooth rotation can be obtained.

  FIG. 4 is a horizontal sectional view of the divided stator 10 of FIG. 1 (cross section of the stator shaft). According to FIG. 4, the teeth 3 are formed in a straight shape with a constant cross section from the back yoke 4 to the collar 2, and the number of turns per unit tooth length of the winding, that is, the turn number density is large on the back yoke side. For this reason, the magnetomotive force NI (N: total number of turns, I: current) is distributed at a larger ratio on the back yoke side.

In the embodiment of the present invention, since the cross process is important, the cross process will be described next. FIG. 5 is a conceptual diagram for explaining the cross processing of the first layer winding. FIG. 6 is a diagram showing a part of the windings in the second and third layers. 5 and 6 together, the direction of the line of cross-process by a horizontal cross-sectional view of the base shows a direction winding the winding of the upper surface i.e. the cross-process surface S _c. As shown in FIG. 5, the first layer cross processing is performed in the direction of the arrow (downward left in FIG. 5), such as winding number (2) → (3) or (4) → (5). Winding is performed while shifting in the direction of the helical axis. When wound to the end on the side of the collar 2, the winding becomes the second layer, and shifting in the return direction and winding are performed. This shift in the return direction takes one turn with no tilt (no shift) as shown by winding number (16) → (17) at the end, and the direction of the tilt in the direction of the arrow in FIG. 6 (upward to the left). Is reversed. Then, at the end on the back yoke 4 side, after one turn (winding number (32) → (33)) with no inclination (no shift), winding number (34) → (35) Invert the slope to the lower left and roll the third layer while shifting. In addition, although the winding number was displayed by changing the font in the drawing, it was distinguished from the part display number by adding parentheses as shown in (2) in this description.

  The first layer cross processing is especially important because it is the basis of the coil winding layer and slips easily on the surface of the insulator. However, as described above, the cross processing starts from the corner corresponding to the acute angle of the skew teeth. Since the process is performed, slippage can be suppressed and turbulence can be prevented. For the second and subsequent layers, the lower winding layer is formed along the skew shape even though the cross processing on the lower winding is less likely to slip than the cross processing on the insulator. Therefore, the starting point is the corner corresponding to the acute corner at the macro level, and slipping can be more reliably prevented.

(Embodiment 2)
FIG. 7 is a diagram for explaining a split stator according to Embodiment 2 of the present invention. In the split stator 10 according to the present embodiment, (1) the teeth covered by the insulator 6 are narrowed from the back yoke 4 side to the collar 2 side so that the widths of the upper surface and the lower surface are narrowed so that both side surfaces approach each other. It is characterized in that it is tapered, and (2) a flat wire groove 6a is attached to the cross surface of the start and end points of the cross process of the insulator 6.

  8 and 9 are sectional views taken along lines VIII-VIII and IX-IX in FIG. 7, respectively. Each of these cross-sectional views is a transverse cross section of the coil shaft, and has a tapered shape in which both side surfaces of the teeth 3 approach each other from the back yoke 4 side to the collar 2 side. With this configuration, in a structure in which a plurality of divided stators are annularly arranged with the flange side perpendicular to the stator axis and the coil axis extending in the radial direction (see FIG. 14), they are adjacent to each other. While preventing the windings of the split stators from overlapping, the number of layers of the coil from the back yoke side to the flange side is made uniform, and the length of the coil in the axial direction can be shortened. In addition, since the width of the teeth on the back yoke side is increased, the magnetic flux is increased, and the outer diameter of the back yoke can be reduced.

The groove 6a of the insulator has a positioning action with respect to the winding 5 when the tooth 3 has the taper, and further has an anti-slip action when being rolled down along the taper. The shape of the groove 6a will be described later. Moreover, although the said groove | channel can also be attached | subjected also to the straight-shaped teeth in Embodiment 1 without the said taper, in this case, a groove | channel has the positioning effect | action of a cross process. The positioning action is an action that determines the starting point and the end point of the cross process in the whole tooth, and suppresses the occurrence of turbulence due to slippage of the rectangular line at the starting point and the end point. In FIG. 7, the groove 6a of the insulator is provided only at both ends of the cross-processed surface and is not provided near the center of the cross-processed surface. This is because turning firmly wound to prevent slippage between the starting point and end point, better to leave it free in the vicinity of the center of the cross-process surface S _c is, the frictional force to prevent slipping locally increased at the corners, Further, it is possible to smoothly cope with deformation such as complicated twisting of a rectangular wire crossing between the starting point and the ending point.

  FIG. 10 is a horizontal sectional view of the split stator shown in FIG. 7, that is, a transverse sectional view of the stator shaft. In the stator formed by the annular circumferential arrangement of the plurality of split stators 10, the teeth 3 are narrowed on the inner peripheral side, and the windings are not easily overlapped between adjacent split stators. It can be seen that the number of turns per tooth unit length is made substantially uniform from the yoke 4) side to the inner circumference (rib 2) side. Thus, by distributing the magnetomotive force NI substantially evenly, local magnetic saturation can be prevented and wasteful power consumption can be prevented.

11 is a cross-sectional view taken along line XI-XI in FIG. FIG. 12 is a partially enlarged view. In the bottom side facing the cross-process surface S _c, grooves 6b are provided continuously with the corners in the vicinity of the center of the bottom surface of the insulator 6. The groove 6b on the bottom surface side facing the cross-treated surface is substantially aligned in the groove width direction and the coil axis direction or the tooth length direction. The groove 6b may have the same depth in the groove width direction, but may be tapered so that the depth in the groove width direction becomes shallower on the collar (inner circumference) side. By providing the groove 6b whose depth in the groove width direction decreases toward the inner peripheral side, slipping can be effectively prevented when the rectangular wire is rolled down in the tapered or stepped teeth. Here, also for the shape of the grooves 6a provided in the corners of the cross-process surface S _c, may be shallow grooves 6b as well as groove width direction of the bottom surface (generally parallel direction from the back yoke side toward the flange side) Or the same depth.

  A manufacturing method by integral molding of the portion (divided core + insulator) from which the winding is removed from the divided stator will be described. In this integral molding, a resin injection molding machine is used. FIG. 13 is a diagram for explaining a method of manufacturing the split core 1 and the insulator by integral molding by injection molding. In this integral molding, the pre-manufactured split core 1 is arranged in the mold 31 and the insulator portion is a space 36 filled with an insulating resin. The insulating resin is heated and pressure is applied and injected into the space 36 of the insulator portion from the gate 31a, which is a gate, and is molded. When the grooves 6a and 6b are provided in the insulator 6 and the corners are rounded, the mold 31 is formed with a female shape corresponding to the grooves 6a and 6b or the rounds.

  The insulating resin preferably has high electrical resistance and heat resistance. In addition, when a thermosetting resin is used, it is necessary to maintain a predetermined temperature × predetermined time in a heat treatment furnace or the like after the above injection step, but it does not soften even when the electric motor becomes hot during use. Excellent in terms of thermal stability. As the thermosetting resin, an epoxy resin, a polyimide resin, or the like is preferable. In addition, when a thermoplastic resin is used, it can be rapidly cooled and solidified after the above injection step, so that the production efficiency can be greatly improved. It is better not to use one having a softening temperature in a certain range. As the thermoplastic resin, polyamide imide resin, polyether sulfone resin, polyphenylene sulfide (PPS) resin, polybutylene terephthalate resin, liquid crystal polymer, and the like are preferable.

  Needless to say, a method of assembling the insulator 6 separately and then assembling the insulator 6 may be used. However, by the integral molding process of the split core 1 and the insulator 6 described above, the assemblability can be improved and the productivity can be greatly improved.

  FIG. 14 shows a stator 50 in which a plurality of the divided stators 10 manufactured as described above are arranged in a ring shape with the collar 2 side arranged radially on the axis side. On the inner side surrounded by the stator 50, an armature or a rotor (not shown) is arranged along the stator axial direction to constitute a rotating portion that rotates in the stator circumferential direction. By using the split stator 10 of the first or second embodiment, the space factor can be increased and the output and energy efficiency of the motor can be improved.

  Although the embodiments and examples of the present invention have been described above, the embodiments and examples of the present invention disclosed above are merely examples, and the scope of the present invention is the implementation of these inventions. It is not limited to the form. The scope of the present invention is indicated by the description of the scope of claims, and further includes meanings equivalent to the description of the scope of claims and all modifications within the scope.

  According to the present invention, it is possible to provide a split stator and a stator that are easy to manufacture and excellent in reliability and magnetic properties at low cost.

It is a figure which shows the division | segmentation stator in Embodiment 1 of this invention. It is a top view for demonstrating the division | segmentation stator of FIG. It is sectional drawing which follows the III-III line of FIG. It is sectional drawing by the surface (horizontal cross section) orthogonal to the stator axial direction of the division | segmentation stator of FIG. It is a figure for demonstrating a cross process (1st layer). It is a figure for demonstrating a cross process (the 2nd layer and a part of 3rd layer). It is a figure for demonstrating the division | segmentation stator in Embodiment 2 of this invention. It is sectional drawing which follows the IIIV-IIIV line | wire of FIG. It is sectional drawing which follows the IX-IX line of FIG. It is sectional drawing by the surface (horizontal cross section) orthogonal to the stator axial direction of the split stator of Embodiment 2 of this invention. It is sectional drawing which follows the XI-XI line of FIG. It is the elements on larger scale of FIG. It is a figure for demonstrating the method to manufacture the division | segmentation stator and insulator of FIG. 7 by integral molding. It is a figure which shows the stator using the division | segmentation stator of embodiment of this invention.

Explanation of symbols

1 split core, 2 brim, 3 teeth, 4 back yoke, 5 rectangular wire (winding), 6 insulator, 6a, 6b groove, 10 split stator, 31 mold, 31a gate (pouring gate), 36 insulator space, 50 stator , R ₁ , R ₂ Insulator corners, _Sc cross-treated surface.

Claims (8)

A split core having teeth;
The split core comprises a plurality of rows, a plurality of layers, and a coil of a wound rectangular wire,
2. The divided stator according to claim 1, wherein the teeth are skew-shaped, and the rectangular coil crosses on one surface starting from a corner of the skew shape of less than 90 °.   The split core has a brim at one end of the tooth and a back yoke at the other end of the tooth, and the teeth have both side surfaces continuously or intermittently from the back yoke side toward the brim side. The split stator according to claim 1, wherein the stator has shapes that approach each other.   The split stator according to claim 1, wherein the rectangular coil is formed on an insulator that covers the split core.   The insulator has four corners corresponding to the skew shape of the split core, and the corners less than 90 ° of the skew shape are smaller than the corners of more than 90 °. The split stator according to claim 3, characterized in that   5. The split stator according to claim 3, wherein a groove for each turn for the rectangular wire is attached to a radius of the corner portion of the insulator on the crossing surface. 6.   6. The split stator according to claim 5, wherein a groove of the insulator is shallow along a groove width direction from the back yoke side to the flange side.   The split stator according to claim 3, wherein the split core and the insulator are integrally formed.   A stator having a plurality of the divided stators according to any one of claims 1 to 7 arranged in an annular shape.

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