JP2013158073A - Core for motor and motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a core for a motor that can effectively utilize an entire core as a magnetic path in the core for the motor made of magnetic powder.SOLUTION: At a core for a motor and the motor, the shape of the core for the motor which is wound with a coil to generate rotational driving force by magnetic action with a magnet comprises: a central core part having a central axis; a plurality of arm parts extending in the radial direction of a circle centering on the central axis from the central core part; and a blade part which is formed at the tip of each of the arm parts and extends from the tip to the circumferential direction of the circle and to the direction parallel to the central axis. At an end surface of the end extended to the direction parallel to the central axis of the blade part, a notch formed toward the arm parts is provided.

Description

  The present invention relates to a motor core and a motor using magnetic powder.

  Generally, a motor includes a stator and a rotor, a magnet is disposed on one side, and a magnetic switching mechanism is provided on the other side. The motor is driven by a magnetic action with the magnet. When the magnetic pole is electrically switched, the action as an electromagnet is utilized, and the core used there is known to use an electromagnetic steel plate or magnetic powder. FIG. 6A is a cross-sectional perspective view of a motor including the stator 1 and the rotor 2. FIGS. 6B and 6C both show a cross section taken along the line II-II of FIG. 6A including the stator 1 and the rotor 2 from the central axis. FIG. 6B shows the internal magnetic flux flow 6 in the case where a laminated core using electromagnetic steel sheets is used for the stator 1. Further, FIG. 6C shows a flow 6 of magnetic flux when a core using magnetic powder is used for the stator 1. Here, as can be seen from the flow of magnetic flux, a technique is known in which a magnetic path is efficiently formed by using a core made of magnetic powder for the stator 1 to improve the efficiency of the motor. (For example, see Patent Document 1)

  Furthermore, in order to improve the efficiency of the motor, for example, there is a shape in which the area of the surface facing either the magnet 1 of the stator 1 or the rotor 2 provided facing the magnet is widened. FIG. 7 shows a cross section in a plane parallel to the rotation axis of the motor component. As shown here, a magnetic powder is used for the motor core 5, which is a stator, and the end thereof is widened facing the magnet 3 to form a structure having substantially the same length as the magnet 3. For this reason, the flow of magnetic flux flowing in and out between the magnet and the core is increased, and the efficiency of the motor is improved. (For example, see Patent Document 2)

  Thus, in the motor shown in FIGS. 6 and 7 using a magnetic powder core in the past, attempts have been made to efficiently form a magnetic path by creating a three-dimensional magnetic flux flow from the stator side inside the core. ing. That is, the flow of magnetic flux in the three-dimensional direction indicates that the magnetic flux flows in the portion facing the magnet at the tip of the core and flows into the opposite magnet from the opposite end through the inside of the core.

Japanese Patent Laid-Open No. 2004-153977 JP 2002-125350 A

  However, in this flow of magnetic flux, it does not pass through the inside of the core, but goes around the end of the core, forms a magnetic path to the salient pole of the adjacent core through the air gap, or adjoins through the air gap. The inventors have discovered that magnetic flux components that form a magnetic path are included in the magnets that do not contribute to the action of attraction and repulsion between the magnets and the electromagnets that drive the rotation of the motor. did. The inventors have found as a new issue to further improve the efficiency of the motor by effectively utilizing the flow of magnetic flux in the core.

  The present invention has been made in consideration of the above points, and an object of the present invention is to provide a motor core and a motor capable of improving the efficiency of the motor.

  The inventors of the present invention have studied the structure of the motor core in various ways, and found that the motor efficiency is improved by suppressing the flow of magnetic flux around the outer periphery at the end of the motor core. The invention has been completed.

  The core for a motor of the present invention is formed at a central core portion having a central axis, a plurality of arm portions extending from the central core portion in a radial direction of a circle centering on the central axis, and a tip of the arm portion, respectively. And a honey part that extends from the tip in a circumferential direction of the circle and a direction parallel to the central axis, and an end surface of an end part of the honey part that extends in a direction parallel to the central axis is provided on the arm part. A notch formed toward the top is provided.

  The motor core, by forming the notch, circulates a portion provided in the direction of being parallel to the central axis in the splash portion, and to the salient pole of the adjacent core via a gap The effect of suppressing the flow of magnetic flux that forms a magnetic path to a magnet that forms a magnetic path or that faces the magnet through a gap is obtained. In other words, the effect of improving the efficiency of the motor by effectively utilizing the flow of magnetic flux in the core by suppressing the magnetic flux component that does not contribute to the action of attraction and repulsion between the magnet and the electromagnet that are the driving force of the motor rotation drive Is obtained.

  Further, in the motor core of the present invention, it is preferable that the notch portion reaches the arm portion.

  The motor core of the present invention has a structure in which the cutout portion reaches the arm portion, whereby the flow of magnetic flux flowing into and out of the arm portion from the honeycomb portion becomes efficient. As a result, an effect of further improving the efficiency of the motor can be obtained. As a result, the magnetic flux flowing into and out of the honey section effectively forms a magnetic path that flows to the arm section, so that the force of attraction and repulsion between the magnet and the electromagnet that drives the rotation of the motor increases. It becomes. Therefore, the driving torque of the rotational drive of the motor provided with these motor cores is further increased.

  Furthermore, the motor core according to the present invention is characterized in that a groove extending in a direction parallel to the central axis is provided on an outer peripheral surface of the honey portion.

  As a result, the motor core of the present invention is provided with a groove on the outer peripheral surface of the honey part in parallel with the central axis, so that the rotational drive of the motor out of the magnetic flux circulating in the circumferential direction of the magnetic flux flowing through the honey part. There exists an effect | action which suppresses more effectively the flow of the magnetic flux which does not contribute to the effect | action of attraction and repulsion with the magnet and electromagnet used as a drive. As a result, since the magnetic flux flowing into and out of the honey portion effectively forms a magnetic path that flows to the arm portion, the attraction / repulsion force between the magnet and the electromagnet that becomes the driving force of the motor rotation increases. It becomes. Therefore, the driving torque of the rotational drive of the motor provided with these motor cores is further increased.

  Furthermore, the motor core according to the present invention includes a coil in the arm portion, and a length of a line segment parallel to the central axis including the coil in the arm portion and a length in the same direction in the honey portion are substantially the same. It has a length.

  Thus, in the motor core according to the present invention, the length of the line segment parallel to the central axis including the coil in the arm portion including the coil and the length of the end surface in the same direction of the honey portion are substantially the same. Thus, the height in the axial direction of the motor product or the like, which is restricted by the height of either one of them, can be minimized. Therefore, the height of the motor product including these motor cores can be minimized.

  Furthermore, the motor core according to the present invention is characterized in that the central core portion, the arm portion, and the splash portion are integrally formed of a green compact using magnetic powder or a sintered body thereof.

  For this reason, by forming the core for a motor of the present invention with a green compact using a magnetic powder or a sintered body thereof, the flow of magnetic flux in the three-dimensional direction is facilitated inside the core, and the magnetic path is effectively It can be formed, and the characteristics of the motor can be improved.

  As a desirable aspect of the present invention, it is preferable to apply the motor core described above to a motor.

  By applying the core for a motor of the present invention to a motor, the characteristics of the motor can be effectively improved.

  According to the motor core and the motor of the present invention, in the flow of magnetic flux, do not pass through the inside of the core, circulate around the end of the core, and form a magnetic path to the salient pole of the adjacent core through the gap, Or the magnetic flux component which forms a magnetic path to an adjacent magnet via a space | gap can be suppressed. For this reason, in this invention, it has the effect of utilizing the flow of the magnetic flux in a core effectively, and improving the efficiency of a further motor.

1A is a cross section perpendicular to the axis of the motor according to the embodiment, and FIG. 1B is a cross section parallel to the axis. FIG. 2A is a diagram illustrating a core state of the motor according to the embodiment, and FIG. 2B is a diagram illustrating a representative state illustrating the flow of magnetic flux according to the embodiment. FIG. 3A shows a core shape of the motor of the embodiment, and FIG. 3B shows a representative state showing the flow of magnetic flux of the embodiment. 4A shows the core shape of the motor of Comparative Example 1, and FIG. 4B shows a representative state showing the flow of magnetic flux of Comparative Example 1. FIG. FIG. 5A is a diagram showing a core shape of the motor of Comparative Example 2, and FIG. 5B is a diagram showing a representative state showing the flow of magnetic flux of Comparative Example 2. FIG. 6 is a cross-sectional view of a conventional motor. FIG. 7 is a cross-sectional view of a conventional motor.

  Embodiments for carrying out the present invention will be described in detail with reference to the drawings. The present invention is not limited by the contents described in the following embodiments. The constituent elements described below include those that can be easily assumed by those skilled in the art and those that are substantially the same. Furthermore, the constituent elements described below can be appropriately combined.

(Embodiment)
1A and 1B are views showing a cross section of a motor according to an embodiment. The motor includes a motor core, a magnet 13, and a yoke 11 covering the outside. The efficiency of the motor is analyzed using a computer for the magnitude of the torque and the direction and magnitude of the magnetic flux of the motor having these shapes. In other words, the efficiency of the motor is compared with the restraint torque, which is the magnitude of the torque generated on the rotating shaft when the motor rotation is 0, as a representative value of the torque value, and from the direction and magnitude of the magnetic flux inside the core. By analyzing magnetic loss, an efficient motor can be evaluated.

  FIG. 1A shows a cross section perpendicular to the rotation axis of the motor. FIG. 1B is a cross-sectional view (cross-sectional view taken along the line bb in FIG. 1A) parallel to the rotation axis of the motor. 1 (a) and 1 (b), the central core portion 16 includes a plurality of arm portions 17 extending in the radial direction of a circle with the central axis as the center. A honey part 18 extending in a direction parallel to the central axis is provided, and the central core part 16, the arm part 17, and the honey part 18 form a motor core. Further, the shaft 12 at the center of the central axis is fixed to the motor core. The coil 15 is wound around the arm portion 17 of the motor core.

  The motor core is formed by laminating plates made of magnetic materials such as soft magnetic materials such as iron and steel, or compacted powder using the above magnetic material powder or coating powder in which an insulating coating is formed on the powder surface. It can be composed of a molded body. Here, it can be manufactured by filling the above-mentioned powder or coating powder into a mold having a predetermined shape and pressurizing it. In particular, a core made of a green compact can be easily molded even in a complicated shape and has excellent manufacturability.

  FIG. 2A is a perspective view of the motor core according to the embodiment. The motor core according to the present embodiment includes a central core portion 25 having a central shaft 26, a plurality of arm portions 27 extending from the central core portion 25 in a radial direction of a circle around the central shaft 26, and A honey part 28 is formed at the tip of each arm part 27 and extends from the tip in a circumferential direction of the circle and in a direction parallel to the central axis 26, and in a direction parallel to the central axis 26 of the honey part 28. A cutout 20 formed toward the arm portion 27 is provided on the end face of the extended end portion.

  FIG. 2B shows the flow of the magnetic flux 6 of the motor core shown in FIG. The flow of the magnetic flux 6 in the portion of the honey portion 28 of the motor core that is not in the same position in the axial direction as the arm portion 27 circulates around the outer peripheral portion of the motor core, and the salient poles of the adjacent core via a gap A magnetic path is formed, or a magnetic flux flows to form a magnetic path to an adjacent magnet through a gap, resulting in magnetic loss. By providing the notch 20, the flow of magnetic flux in a portion not in the same position in the axial direction as the arm portion 27 is directed toward the arm portion 27.

  Here, by providing a honey portion 28 that is larger than the cross-sectional area of the end portion of the arm portion 27, the area of the surface of the honey portion 28 that faces the magnet is increased, so that the opposing magnet and the honey portion 28 flow into each other. In addition to the conventional effect of increasing the emitted magnetic flux, the effect of forming a magnetic path from the honey part 28 to the arm part 27 is obtained.

  The shape of the cutout 20 is not particularly limited, but it may be provided asymmetrically as viewed from the arm portion 27 or a plurality of cutouts 20 may be provided. This is because the same effect can be obtained even in this case.

  Further, in the honey portion 28, a notch is uniformly cut out at a portion opposite to the rotation direction viewed from the arm portion 27 (the rotation direction with the central axis of the core, for example, the arrow x direction in FIG. 2A). May be provided. The flow of the magnetic flux 6 flowing into and out of the honey section 28 from the magnet positioned forward in the rotation direction forms a magnetic path to the arm section 27, so that the honey section 28 is viewed in the rotation direction rearward as viewed from the arm section 27. This is because the flow of the magnetic flux 6 is reduced. Even in this case, the same effect can be obtained.

  However, when there is no symmetry in the motor core, there is a case where influences such as vibrations may occur during rotation, so that the structure of the entire motor core needs to be fully examined.

  Here, a structure in which the notch 20 reaches the arm is more preferable. By adopting a structure in which the notch 20 reaches the arm portion 27, the flow of the magnetic flux 6 in the portion not located in the same axial position as the arm portion 27 in the honey portion 28 is directed to the arm portion 27. It will be. Therefore, the magnetic flux 6 flowing into and out of the honey section 28 effectively forms a magnetic path that passes through the arm section 27.

  FIG. 3A is a perspective view of the motor core according to the embodiment. FIG. 3B shows the flow of the magnetic flux 6 of the motor core shown in FIG. The motor core according to the present embodiment includes a central core portion 35 having a central axis 36, a plurality of arm portions 37 extending from the central core portion 35 in a radial direction of a circle around the central axis 36, and Each of the arm portions 37 includes a honey portion 38 formed at the tip of the arm portion 37 and extending from the tip in a direction parallel to the circumferential direction of the circle and the central axis 36, and in a direction parallel to the central axis 36 of the honey portion 38. A cutout 30 formed toward the arm portion 37 is provided on the end face of the extended end portion. Furthermore, a groove 31 extending in a direction parallel to the central axis is provided on the outer peripheral surface of the honeycomb portion.

  The groove 31 is provided on the outer peripheral surface of the honey portion 38 and effectively forms a magnetic path that passes through the arm portion 37 from the outer periphery of the honey portion 38. That is, the magnetic flux 6 flowing on the outer peripheral surface of the honey part 38 forms a magnetic path that does not pass through the arm part 37, forms a magnetic path to the salient pole of the adjacent core via the gap, or passes through the gap. It includes one that forms a magnetic path to the opposing magnet. On the outer peripheral surface of the honey part 38, the magnetic flux 6 that circulates around the honey part 38 effectively passes through the arm part 37 by providing a groove 31 in an extension line part with the arm part 37 parallel to the axial direction. To form a magnetic path.

  Although the shape and size of the groove 31 are not particularly limited, the position of the groove 31 is formed on the outer peripheral surface of the extension portion on the extension line of the arm portion 37, and the depth of the groove 31 is set on the extension portion. A magnetic path can be effectively formed by setting it to the same thickness as 38. In this case, since the mechanical strength may be impaired by forming the groove 31, it is necessary to fully examine the structure of the entire motor core.

  It is preferable that the central core part 35, the arm part 37, and the honey part 38 according to the embodiment are integrally formed of a green compact using magnetic powder or a sintered body thereof.

  The magnetic powder can be composed of a powder formed of a magnetic material such as a soft magnetic material such as iron or steel, or a green compact using a coating powder in which an insulating coating is formed on the surface of such a powder. Here, it can be manufactured by filling the above-mentioned powder or coating powder into a mold having a predetermined shape and pressurizing it. In particular, a core made of a green compact can be easily molded even in a complicated shape and has excellent manufacturability.

  When an exciting current is applied to the coil wound around the arm portion 37, the arm portion 37 and the honey portion 38 have an electromagnet action, and an attractive / repulsive action acts between the opposing magnets. By applying independent excitation currents to the three arm portions 37 and controlling the current values, rotational driving is generated in the motor core, and this force is generated in the rotating shaft. With respect to this driving force, the value of the constraint torque, which is the maximum value of the torque generated on the rotating shaft when the rotational speed is 0, is calculated by a computer.

  The evaluation of motor characteristics includes the relationship between torque and excitation current, the relationship between torque and motor rotation speed, motor efficiency consisting of the input / output ratio to the motor, etc., but here the rotation when the motor rotation speed is 0 The maximum torque produced on the shaft can be used for comparison.

  The contents of the present invention will be described more specifically with reference to examples and comparative examples, but the present invention is not limited to the following examples.

Example 1
In Example 1, a motor core having the shape shown in FIG. 2 was produced with the motor having the shape shown in FIG. 1, and the magnitude of the torque and the direction and magnitude of the magnetic flux were analyzed using a computer. .

  The motor core includes three salient poles extending from the central core portion 25 in the radial direction of the circle centering on the central axis 26 and formed at a distance from each other, and has a width of 1.5 mm and a height (the center of the core). (Length in a direction parallel to the axis) 5.95 mm arm part 27, and a tip part of arm part 27 is provided with a honey part 28 extending in the circumferential direction of the circle and the direction parallel to the central axis. The motor core was obtained by compacting magnetic powder and using a material having a magnetic property of a saturation magnetic flux density of 1.6 T.

  Further, the honey portion 28 formed at the end of the motor core is a connection portion with the arm portion 27, the height L27 is 5.95 mm, and the circumferential end height L28 of the honey portion 28 is 10.57 mm. It was. In the honey part 28 formed at the tip of the arm part 27, a notch 20 formed toward the arm part 27 is provided on an end surface provided extending in a direction parallel to the central axis.

  A 0.09 mm diameter coil was wound around the arm portion 27 for 200 turns. Further, magnets 13 and 14 were provided as shown in FIG. 1 so as to face the honey portion 28 of the motor core with a gap of 0.205 mm. Each magnet is fixed to a yoke 11 made of cold-rolled steel plate having a thickness of 0.4 mm. The magnet is a permanent magnet having a residual magnetic flux density of 415 mT and a holding force of 255 kA / m, and each magnetic pole is reversed in the radial direction. An excitation current is supplied by applying a voltage of 4.5 V to the coil 15, and a driving force for rotating the motor is obtained by the attractive / repulsive force with the magnets 13 and 14. The motor has a yoke outer diameter of 12.0 mm and a height of 14.0 mm.

As a result of calculating the torque of the motor using this motor core, the constraint torque, which is the value of the maximum torque when the rotation speed is 0, is 1.343 [mN · m], and the result is shown in Table 1. Show.
As shown in FIG. 2 (b), the state of the magnetic flux flowing in the motor core changes depending on the position of the opposing magnet, and the direction and magnitude of the magnetic flux flowing into and out of the honey section changes. A magnetic path was formed from the circumferential end of the honey portion to the arm portion in the state where the most magnetic flux flows in and out. For this reason, there is no waste in the formation of the magnetic path, the magnetic loss is reduced, and as a result of comparison with the torque value as an evaluation of the efficiency of the motor, the effect of increasing the torque value is recognized.

  The magnetic flux component that does not pass through the core, circulates around the end of the core, forms a magnetic path to the salient pole of the adjacent core through the air gap, or forms a magnetic path to the adjacent magnet through the air gap. Suppression is confirmed. In addition, these magnetic flux components contribute to the attractive and repulsive action of the magnet and electromagnet that are the driving force of the motor's rotational drive, effectively utilizing the flow of magnetic flux in the core and further improving the efficiency of the motor. It was.

[Example 2]
In Example 2, a motor core having the shape shown in FIG. 3 was produced with a motor having the shape shown in FIG. 1, and the magnitude of the torque and the direction and magnitude of the magnetic flux were analyzed using a computer. .

  In the motor core, the honey portion 38 formed at the end portion of the motor core is a connection portion with the arm portion 37, the height L37 is 5.95 mm, and the height L38 of the circumferential end portion of the honey portion 38 is 10. .57 mm. A cutout 30 formed toward the arm portion 37 is provided on the end portion provided by extending in a direction parallel to the central axis 36 in the honeycomb portion 38 formed at the tip of the arm portion 37. Furthermore, here, there is a further feature with respect to the first embodiment in that a groove 31 parallel to the central axis 36 is formed on the outer peripheral surface of the honeycomb portion 38. Here, the depth of the groove 31 in the radial direction is set to be approximately the same as the thickness of the honey portion 38. The motors having these shapes were analyzed using a computer for the magnitude of the torque and the direction and magnitude of the magnetic flux.

As a result of calculating the torque of the motor using this motor core, the binding torque that is the value of the maximum torque when the rotation speed is 0 is 1.362 [mN · m], and the result is shown in Table 1. Show.
In addition, as shown in FIG. 3B, the state of the magnetic flux flowing in the motor core varies depending on the position of the opposing magnet, and the direction and magnitude of the magnetic flux flowing into and out of the honey section changes. In the state where the magnetic flux flowing into and out of the part is the largest, a magnetic path passing through the circumferential end part and the arm part in the honey part is formed. Furthermore, by providing a groove on the outer peripheral surface of the honey section, a magnetic path that flows into and out of the arm section is effectively formed, so there is no waste in forming the magnetic path and there is little magnetic loss, resulting in increased torque. The effect of was recognized.

[Comparative Example 1]
In Comparative Example 1, a motor core having the shape shown in FIG. 4A is manufactured by the motor shown in FIG. 1 having the same structure as that of Example 1, and the magnitude of the torque and the direction and magnitude of the magnetic flux are calculated. The analysis using was performed.
Here, the motor core includes three salient poles radially spaced from the central core portion 45, and includes an arm portion 47 having a width of 1.5 mm and a height of 5.95 mm. The tip of each of them is concentrically extended in a circular arc shape and has a honey portion 48 having a uniform height. That is, the height L48 of the honey portion 48 of the motor core is a motor core shape that is substantially the same height as the arm portion 47. That is, the result of evaluation of the obtained motor is due to the difference in the shape of the motor core.

As a result of calculating the torque of the motor using this motor core, the constraining torque, which is the value of the maximum torque when the rotational speed is 0, is 1.329 [mN · m], and the result is shown in Table 1. Furthermore, a typical state showing the flow of the magnetic flux 6 in the motor core is shown in FIG.
The direction and magnitude of the magnetic flux 6 flowing into and out of the honey section varies depending on the position of the opposing magnet. For example, in the state where the magnetic flux flowing into and out of the honey section is the largest, the arc-shaped end in the honey section A magnetic path is formed between the part and the arm part. However, since the area of the honey part facing the magnet is smaller than that of the above embodiment, the total amount of magnetic flux inflow / outflow is small, so that the value of the restraining torque is reduced.

(Comparative Example 2)
In Comparative Example 2, a motor core having the shape shown in FIG. 5 (a) was produced with the motor shown in FIG. 1 having the same structure as that of Example 1, and the magnitude of the torque and the direction and magnitude of the magnetic flux were calculated. The analysis using was performed.
Here, the motor core includes three salient poles radially spaced from the central core portion 55, and includes an arm portion 57 having a width of 1.5 mm and a height of 5.95 mm. A tip 58 is provided with a conical portion 58 extending concentrically in a circular arc shape. The height L58 of the honey part 58 of the motor core was uniformly 10.57 mm. That is, the shape of the motor core is uniformly higher than the height of the arm portion 57. In addition to the motor core shape shown here, for the motor having the same structure as in Example 1, the magnitude of the torque and the direction and magnitude of the magnetic flux were analyzed using a computer. That is, the obtained result is due to the difference in the shape of the motor core.

As a result of calculating the torque of the motor using this motor core, the constraint torque, which is the value of the maximum torque when the rotation speed is 0, was obtained as 1.306 [mN · m], and the results are shown in Table 1. . A representative state showing the flow of magnetic flux in the motor core is shown in FIG.
The direction and magnitude of the magnetic flux 6 flowing into and out of the honey section varies depending on the position of the opposing magnet. For example, in the state where the magnetic flux flowing into and out of the honey section is the largest, In the area of the honey part that is not located at the same position, the flow of magnetic flux circulates around the honey part. Therefore, the circulating magnetic flux does not flow into and out of the arm portion. As a result, the formation of the magnetic path is wasted and magnetic loss has led to a reduction in motor torque.

  As a result of examining the magnitude and direction of the magnetic flux for the motor core using magnetic powder, the rotational torque of the motor was reduced by the magnetic flux circulating in the circumferential direction at the end of the core facing the magnet. By suppressing the magnetic flux that circulates, the magnetic loss was reduced, and the decrease in rotational torque could be prevented.

  As described above, the core and magnet structure of the motor according to the present invention can be suitably used for the constituent members of the motor. A motor having this core can be suitably used for a motor that requires high output, such as an electric vehicle and a hybrid vehicle, in addition to those used for small electrical products.

DESCRIPTION OF SYMBOLS 1 Stator 2 Rotor 3, 13, 14 Magnet 5 Motor core 6 Magnetic flux 11 Yoke 12 Shaft 15 Coil 16, 25, 35, 45, 55 Central core part 17, 27, 37, 47, 57 Arm part 18, 28, 38 , 48, 58 Honey part 20, 30 Notch 26, 36 Center axis 31 Groove

Claims (6)

  A central core portion having a central axis; a plurality of arm portions extending from the central core portion in a radial direction of a circle centering on the central axis; and a tip of the arm portion. A notch formed toward the arm portion on the end surface of the end portion extending in a direction parallel to the central axis of the honeycomb portion. A motor core, characterized in that is provided.   The motor core according to claim 1, wherein the cutout portion reaches the arm portion.   The motor core according to claim 1, wherein a groove extending in a direction parallel to the central axis is provided on an outer peripheral surface of the honey portion.   The arm portion includes a coil, and a length of a line segment parallel to the central axis including the coil in the arm portion and a length in the same direction in the honey portion are substantially the same. The motor core according to claim 1.   5. The central core portion, the arm portion, and the splash portion are integrally formed of a green compact using magnetic powder or a sintered body thereof. Motor core.   A motor comprising the motor core according to claim 1.

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