JP2011200081A - High-speed rotating motor and rotor used for the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a high-speed rotating motor and a rotor forming a stress-relaxation hole in a hole shape symmetrical to a plane passing at a central position, in the peripheral direction of salient poles, including the axial center of the rotor on the same circumference as the outer peripheral surface of the base of a rotor core, dispersing a stress concentration working to the rotor core resulting from a centrifugal force and being capable of increasing the critical number of revolution.SOLUTION: The rotor 3 is configured, by mutually displacing the first and second rotor cores 4 and 5 by half a salient pole pitches manufactured in the same shape disposing the salient poles 4b and 5b at equiangular pitches in the circumferential direction on the outer peripheral surfaces of cylindrical bases 4a and 5a in the circumferential direction and fixing the rotor cores 4 and 5 coaxially to a rotating shaft 2 inserted into the bases 4a and 5a. The stress-relaxation hole 20 is formed into a shape that is symmetric with respect to the plane containing boundaries with the bases 4a and 5a and the salient poles 4b and 5b to each of the salient poles 4b and 5b and passing the axial center of the rotating shaft 2 and centers, in the circumferential direction of the salient poles 4b and 5b so as to penetrate the first and second rotor cores 4 and 5 in the axial direction.

Description

  The present invention relates to a high-speed rotary electric motor suitable for being applied to, for example, an electric motor for an automobile electric supercharger and a rotor used for the high-speed rotary electric motor.

  A conventional switched reluctance motor includes a stator having a plurality of pairs of pole portions that project radially inward to face each other and extend in the axial direction, and is rotatably disposed in the stator. A rotor having a plurality of pairs of salient poles that protrudes radially outward and can be opposed to the pole portions while maintaining a predetermined gap, and is wound around each pair of pole portions of the stator A plurality of coils are provided, and a hole is formed in each salient pole so as to extend in the counter-rotation direction side and from the outside to the rotation direction side and to the inside (for example, see Patent Document 1).

Japanese Patent No. 3633106

  In an electric supercharger for automobiles, the exhaust turbine usually rotates at a high speed of about several tens of thousands rpm to a maximum of about 200,000 rpm, so that the centrifugal force acting on the motor rotor fixed to the shaft of the exhaust turbine is extremely high. growing. A conventional switched reluctance motor is suitable for being applied to an electric motor of an electric supercharger for automobiles because the rotor is manufactured by laminating electromagnetic steel plates and is robust. desired.

  Here, in order to increase the critical rotational speed, it is effective to increase the rotor shaft diameter and increase the rigidity of the rotor. However, since the rotor is made of an iron material, increasing the shaft diameter while keeping the outer diameter of the rotor constant leads to a decrease in the iron portion of the rotor and an increase in the stress value. On the other hand, when the outer diameter of the rotor is increased in accordance with the increase in the diameter of the shaft, a decrease in the iron portion of the rotor can be suppressed, but the inertia is increased. Furthermore, increasing the outer diameter of the rotor increases the centrifugal force and increases the stress value. The smaller the number of salient poles of the rotor, the heavier the salient poles, and the greater the influence of stress.

  In the conventional switched reluctance motor, since the hole is formed in each salient pole, the weight of the salient pole is reduced correspondingly, and the centrifugal force acting on the rotor is reduced. However, the formation of the hole was made to reduce the magnetic attractive force at the time of switching the energization while maintaining the desired torque, and to alleviate the influence of the stress acting on the rotor due to the centrifugal force Is not considered at all. That is, since the hole is formed on the anti-rotation direction side and the outside of the salient pole, the influence of the stress acting on the rotor due to the centrifugal force cannot be reduced.

  The present invention has been made in order to solve such a problem, and includes a stress relief hole including a rotor axial center on the same circumference as a base outer peripheral surface of the rotor core. A high-speed rotary motor that is formed in a symmetric hole shape with respect to a plane passing through the center position in the circumferential direction, disperses stress concentration acting on the rotor core due to centrifugal force, and can increase the critical rotational speed, and used in the motor The purpose is to obtain a rotor.

  The high-speed rotary electric motor according to the present invention includes a first rotor core and a second rotor core that are manufactured in the same shape in which salient poles are arranged on the outer peripheral surface of a cylindrical base portion at an equiangular pitch in the circumferential direction. Are arranged on the inner peripheral side of the first stator core and the second stator core, respectively, and are arranged with a half salient pole pitch shifted in the circumferential direction, and are coaxially fixed to the rotating shaft inserted through the base portion. And a field means that is disposed on the stator and generates a field magnetic flux so that the salient poles of the first rotor core and the salient poles of the second rotor core have different polarities. And an axial magnetic path forming member extending in the axial direction so as to connect the core back outer peripheral surface of the first stator core and the core back outer peripheral surface of the second stator core. . The stress relaxation hole is symmetric with respect to a plane that includes the boundary between the base and the salient pole and passes through the axis of the rotation shaft and the circumferential center of the salient pole with respect to each of the salient poles. In such a shape, the first rotor core and the second rotor core are penetrated in the axial direction.

According to the present invention, the stress relaxation hole is formed in a symmetrical shape with respect to a plane including the boundary between the base and the salient pole and passing through the axis of the rotating shaft and the circumferential center of the salient pole.
Therefore, the weight of the salient pole is reduced, and the centrifugal force acting on the rotor during high speed rotation is reduced. In addition, the iron weight parts on both sides in the circumferential direction of the stress relief hole of the salient pole are separated in the circumferential direction across the stress relief hole, and at high speed rotation, the centrifugal force is centered on the iron weight part from the axis of the rotating shaft. Acts in the direction passing through. As a result, the centrifugal force component perpendicular to the line segment connecting the axis of the rotating shaft and the center of the salient pole in the circumferential direction increases, and stress that deforms the inner circumference of the base into an ellipse close to a circle is generated. Acts on the first and second rotor cores. Then, stress concentration acting on the first and second rotor cores due to the centrifugal force is alleviated. As a result, without increasing the outer diameter of the rotor, the diameter of the rotating shaft can be increased to increase the rigidity of the rotor, the number of dangerous rotations can be increased, and the increase in inertia can be suppressed. .

1 is a partially broken perspective view showing a main configuration of a high-speed rotary electric motor according to Embodiment 1 of the present invention. It is a front view which shows the rotor core in the rotor of the high speed rotary electric motor which concerns on Embodiment 1 of this invention. It is a figure which shows the displacement vector which generate | occur | produces in a rotor core when rotating the rotor of the comparative example in which the stress relaxation hole was abbreviated at high speed. It is a principal part enlarged view of FIG. It is a figure which shows the displacement vector which generate | occur | produces in a 1st rotor core when rotating the rotor of this invention at high speed. It is a principal part enlarged view of FIG. It is a contour figure of the orthogonal displacement component which occurs in a rotor core when rotating the rotor of a comparative example at high speed. It is a contour figure of the orthogonal displacement component which occurs in the 1st rotor core when rotating the rotor of this invention at high speed. It is a contour figure of the orthogonal displacement component which occurs in the 1st rotor core when rotating the rotor of this invention at high speed. It is a figure which shows the relationship between the maximum stress value which generate | occur | produces in a 1st rotor core at the time of high speed rotation, and the radial direction position of a stress relaxation hole. It is a front view which shows the rotor core in the rotor of the high-speed rotary electric motor which concerns on Embodiment 2 of this invention.

  Hereinafter, preferred embodiments of a magnetic inductor type rotating machine according to the present invention will be described with reference to the drawings.

Embodiment 1 FIG.
1 is a partially broken perspective view showing a main configuration of a high-speed rotary electric motor according to Embodiment 1 of the present invention, and FIG. 2 shows a rotor core in the rotor of the high-speed rotary electric motor according to Embodiment 1 of the present invention. It is a front view.

  In FIG. 1, a high-speed rotating motor 1 is a magnetic inductor type synchronous rotating machine, and surrounds a rotor 3 and a rotor 3 that are coaxially fixed to a rotating shaft 2 made of a massive magnetic material such as iron. The stator 7 is formed by winding a stator coil 11 as a torque generating drive coil around the stator core 8 arranged in this manner, a field coil 12 as field means, the rotor 3, and the stator. 7 and a housing 13 that houses the field coil 12.

  The rotor 3 is produced by laminating and integrating a predetermined number of magnetic steel plates and the first and second rotor cores 4 and 5 produced by laminating and integrating a large number of magnetic steel plates formed in a predetermined shape, for example. And a disk-shaped partition wall 6 having a rotation shaft insertion hole (not shown) drilled at the axial center position. The first and second rotor cores 4 and 5 are formed in the same shape, and cylindrical base portions 4a and 5a each having a rotation shaft insertion hole 19 formed at an axial center position, and outer peripheral surfaces of the base portions 4a and 5a. It is composed of salient poles 4b and 5b that are provided so as to project radially outward and extend in the axial direction, and are provided at two equiangular pitches in the circumferential direction. Furthermore, the stress relaxation hole 20 is formed so as to penetrate in the axial direction at the boundary between the base portions 4a and 5a and the salient poles 4b and 5b. The first and second rotor cores 4, 5 are arranged with a semi-saliency pitch shift in the circumferential direction, are arranged in close contact with each other via the partition wall 6, and are inserted through the rotation shaft insertion holes 19. It is configured to be fixed to the shaft 2. The rotor 3 is rotatably disposed in the housing 13 with both ends of the rotating shaft 2 supported by bearings (not shown).

  The stator core 8 includes first and second stator cores 9 and 10 that are manufactured by laminating and integrating a large number of magnetic steel plates formed in a predetermined shape. The first stator core 9 includes a cylindrical core back 9a, and teeth 9b that are provided radially inwardly from the inner peripheral surface of the core back 9a and are provided with six equiangular pitches in the circumferential direction. Prepare. A slot 9c that opens to the inner peripheral side is defined by a core back 9a and an adjacent tooth 9b. The second stator core 10 is manufactured in the same shape as the first stator core 9, and has a cylindrical core back 10 a and is projected radially inward from the inner peripheral surface of the core back 10 a, and the like in the circumferential direction. And six teeth 10b provided at an angular pitch. A slot 10c that opens to the inner peripheral side is defined by a core back 10a and an adjacent tooth 10b. The first and second stator cores 9 and 10 are arranged so that the circumferential positions of the teeth 9b and 10b coincide with each other, and the first and second rotor cores 4 and 5 are separated between the axial thickness separation of the partition walls 6, respectively. Is disposed in the housing 13 so as to surround the housing.

  The stator coil 11 is a three-phase coil wound in a so-called concentrated winding method in which conductor wires are wound around teeth 9b and 10b that are paired in the axial direction without straddling the slots 9c and 10c. Have That is, the stator coil 11 is configured by sequentially winding three phases of U, V, and W twice in a concentrated manner on six pairs of teeth 9b and 10b facing in the axial direction. And the coil end of the phase coil of each phase does not have the mutually cross | intersecting overlap regarding the circumferential direction.

The field coil 12 is a cylindrical coil in which a conductor wire is wound in a cylindrical shape, and is interposed between the core backs 9 a and 10 a of the first and second stator cores 9 and 10.
The housing 13 is made of a massive magnetic material such as iron and is disposed so as to be in close contact with the outer peripheral surface of the core back 9a of the first stator core 9 and the outer peripheral surface of the core back of the second stator core 10. A directional magnetic path forming member is configured. When the housing 13 is made of a nonmagnetic material, members made of a magnetic material such as iron are used as the outer peripheral surface of the core back 9 a of the first stator core 9 and the core back of the second stator core 10. What is necessary is just to arrange | position so that an outer peripheral surface may be contact | connected.

  Next, the shapes and positions of the stress relaxation holes 20 in the first and second rotor cores 4 and 5 will be described with reference to FIG.

The first and second rotor cores 4, 5 have two salient poles 4 b, 5 b projecting radially outward from the outer peripheral surfaces of the base portions 4 a, 5 a, and are symmetrical with respect to the axis O. Yes. The circumferential width θ1 of the outer peripheral surfaces of the salient poles 4b and 5b is 70 °, and the circumferential width θ2 between the rising portions of the salient poles 4b and 5b from the base portions 4a and 5a is 90 °.
The stress relaxation hole 20 is formed in a radially outwardly convex cross-sectional shape formed of a part of an elliptic curve whose outer peripheral side has a long axis as a circumferential direction. The stress relaxation hole 20 is formed symmetrically with respect to a plane including the axis O of the first and second rotor cores 4 and 5 and passing through the center in the circumferential direction of the salient poles 4b and 5b. The stress relaxation hole 20 is formed in a region including the boundary between the base portions 4a and 5a and the salient poles 4b and 5b, and its circumferential width θ3 is 40 °. Thereby, the salient poles 4b and 5b are formed in an arch shape.

  Here, the circumferential widths θ1 and θ2 of the salient poles 4b and 5b in the first and second rotor cores 4 and 5 are 70 ° and 90 °, respectively, but the circumferential widths θ1 and θ2 are limited to this. It is not a thing. The circumferential widths θ1 and θ2 are appropriately set in relation to the slot opening widths of the first and second stator cores 9 and 10, for example. Further, although the circumferential width θ3 of the stress relaxation hole 20 is 40 °, the circumferential width θ3 is not limited to this. The circumferential width θ3 avoids magnetic saturation on both sides in the circumferential direction of the stress relaxation holes 20 of the salient poles 4b and 5b, that is, both ends of the arch shape, and secures a weight component for generating centrifugal forces F1 and F2 described later. From this point of view, when the circumferential width θ2 of the salient poles 4b and 5b is 90 °, it is preferable that the circumferential width θ3 of the stress relaxation hole 20 does not exceed 45 °.

Next, the operation of the high-speed rotating electric motor 1 configured as described above will be described.
When the field coil 12 is energized, the magnetic flux enters the salient poles 4b of the first rotor core 4 from the teeth 9b of the first stator core 9 as indicated by arrows in FIG. The base 4a is entered through both sides of the stress relaxation hole 20 in the circumferential direction. Part of the magnetic flux that has entered the base portion 4a flows in the axial direction in the base portion 4a and the partition wall 6, and the remaining portion of the magnetic flux flows inward in the radial direction in the base portion 4a to reach the rotary shaft 2, and in the rotary shaft 2 It flows in the axial direction and enters the second rotor core 5. Then, the magnetic flux that has entered the second rotor core 5 flows radially outward in the base portion 5a, passes through both sides of the stress relaxation hole 20 of the salient pole 5b in the circumferential direction, and flows to the outer peripheral surface side of the salient pole 5b. The teeth 10b of the second stator core 10 are entered. The magnetic flux that has entered the teeth 10 b of the second stator core 10 flows radially outward in the teeth 10 b and the core back 10 a and enters the housing 13. The magnetic flux that has entered the housing 13 flows in the housing 13 in the axial direction and returns to the core back 9 a of the first stator core 9.

  At this time, since the salient poles 4b and 5b of the first and second rotor cores 4 and 5 are shifted by a half salient pole pitch in the circumferential direction, when viewed from the axial direction, the magnetic flux is generated between the N pole and the S pole. It acts as if it were arranged alternately in the direction. As a result, the high-speed rotary electric motor 1 is provided with a 6-slot concentrated winding type stator coil 11 for a 4-pole rotor 3 consisting of 2 poles of N poles and 2 poles of S poles connected in the axial direction. It operates as a magnetic inductor type synchronous rotating machine.

  Next, the stress relaxation effect by the stress relaxation hole 20 will be described with reference to FIGS. The results of stress analysis under the condition where the rotor is rotated at high speed are shown in FIGS. FIG. 3 is a view showing a displacement vector generated in the rotor core when the rotor of the comparative example in which the stress relaxation hole is omitted is rotated at a high speed, and FIG. 4 is an enlarged view of a main part of FIG. FIG. 5 is a diagram showing a displacement vector generated in the first rotor core when the rotor of the present invention is rotated at high speed, and FIG. 6 is an enlarged view of a main part of FIG. 3 to 6, the solid line indicates the rotor core shape before high speed rotation, the dotted line indicates the rotor core shape at high speed rotation, and the arrow indicates the displacement vector.

  In the rotor core 30 of the comparative example, as shown in FIGS. 3 and 4, the centrifugal force F caused by high-speed rotation passes through the center in the circumferential direction of the salient pole 32 and faces the rotor radially outward. Acts on the core 30. As shown in FIG. 3, the displacement vectors at the salient poles 32 are substantially aligned in the left-right direction. The displacement vector at portion A of the rotor core 30 is also directed in the left-right direction in FIG. Thereby, the rotor core 30 extends in the left-right direction in FIG. 3, and the circular rotation shaft insertion hole 33 of the base 31 is deformed into an elliptical shape. Then, the stress is concentrated on the inner peripheral side of the base 31 that is shifted by approximately 90 ° from the circumferential central portion of the salient pole 32.

  In the first rotor core 4, since the stress relaxation hole 20 is formed so as to include the boundary between the base portion 4 a and the salient pole 4 b, the iron weight portion of the circumferential one side region of the stress relaxation hole 20 of the salient pole 4 b And the iron weight part of the other area | region of the circumferential direction of the stress relaxation hole 20 of the salient pole 4b apparently exists apart in the circumferential direction across the stress relaxation hole 20. Therefore, when the first rotor core 4 rotates at a high speed, as shown in FIG. 5, the centrifugal force F1 due to the iron weight portion in the circumferential one side region of the stress relaxation hole 20 of the salient pole 4b and the stress of the salient pole 4b. Centrifugal force F <b> 2 due to the iron weight portion in the other side region of the relaxation hole 20 acts on the first rotor core 4. Centrifugal force F1 acts radially outward from the axial center of the first rotor core 4 through the center of gravity of the iron weight portion in the circumferential one side region of the stress relaxation hole 20 of the salient pole 4b. Then, it acts radially outwardly from the axial center of the first rotor core 4 through the center of gravity of the iron weight portion in the other region in the circumferential direction of the stress relaxation hole 20 of the salient pole 4b.

  At this time, since the stress relaxation hole 20 is formed in a hole shape that includes the axis of the first rotor core 4 and is symmetric with respect to a plane that passes through the circumferential center of the salient pole 4b, the centrifugal force F1, The size of F2 is the same. And the centrifugal force component parallel to the line segment which connects the axial center of the 1st rotor core 4 and the circumferential direction center of the salient pole 4b becomes small, and the centrifugal force component orthogonal to this line segment becomes large.

  Thereby, in FIG. 5, the displacement vector in the upper region of the salient pole 4b is directed obliquely upward, and the displacement vector in the lower region of the salient pole 4b is oriented obliquely downward. And the displacement vector in the A portion of the first rotor core 4 is also directed obliquely upward in FIG. Therefore, the first rotor core 4 extends in the left-right direction and the up-down direction in FIG. 5, and the circular rotation shaft insertion hole 19 of the base portion 4 a is compared with the elliptical shape in the rotation shaft insertion hole 33 of the rotor core 30 of the comparative example. It is transformed into an ellipse with a short distance between the two focal points. The stress is distributed almost uniformly in the region between the salient poles 4b on the inner peripheral side of the base portion 4a, and the stress acting on the first rotor core 4 is relaxed.

  Here, FIG. 7 and FIG. 8 show the results of the stress analysis under the condition where the rotor is rotated at a high speed. FIG. 7 is a contour diagram of orthogonal displacement components generated in the rotor core when the rotor of the comparative example is rotated at high speed, and FIG. 8 is generated in the first rotor core when the rotor of the present invention is rotated at high speed. It is a contour figure of the orthogonal displacement component to do. The orthogonal displacement component is a displacement component orthogonal to a line segment connecting the axis of the rotor core and the center of the salient pole in the circumferential direction. In the contour diagrams of FIG. 7 and FIG. 8, the orthogonal displacement component increases as the density increases.

  From FIG. 7, it can be seen that the orthogonal displacement component in the portion A of the rotor core 30 is small. In other words, the displacement generated in the rotor core 30 due to the centrifugal force is dominated by a component parallel to the line segment connecting the axis of the rotor core 30 and the center in the circumferential direction of the salient pole 32. Therefore, the rotation shaft insertion hole 33 is deformed into an elliptical shape between the two focal points, and the stress is concentrated in the central portion between the salient poles 32 on the inner peripheral side of the base portion 31.

  From FIG. 8, it can be seen that the orthogonal displacement component in part A of the first rotor core 4 is significantly larger than that of the rotor core 30 of the comparative example. In other words, the displacement generated in the first rotor core 4 due to the centrifugal force is a component perpendicular to the line segment that reduces the line segment connecting the axis of the first rotor core 4 and the circumferential center of the salient pole 4b. Becomes significantly larger. Therefore, the rotation shaft insertion hole 19 has a shorter oval shape between the two focal points than the rotation shaft insertion hole 33 of the comparative example, and is closer to a circle. As a result, the stress is distributed almost uniformly in the region between the salient poles 4b on the inner peripheral side of the base portion 4a, and the stress concentration is relaxed.

  Next, the relationship between the radial position of the stress relaxation hole 20 and the maximum stress value is shown. FIG. 9 is a contour diagram of orthogonal displacement components generated in the first rotor core when the rotor of the present invention is rotated at a high speed. FIG. 9A shows a stress relaxation hole formed in the base region. FIG. 9B shows the case where the center of the stress relaxation hole is located at the boundary between the salient pole and the base, and FIG. 9C shows the stress relaxation hole within the salient pole region. The case where it is formed is shown. In FIG. 9, the thin line shows the state before the deformation of the first rotor core. FIG. 10 is a diagram showing the relationship between the maximum stress value generated in the first rotor core during high-speed rotation and the radial position of the stress relaxation hole. In FIG. 10, the vertical axis represents the maximum stress value generated in the first rotor core, and the horizontal axis represents the radial position of the center of the stress relaxation hole.

  From (a) to (c) of FIG. 9, it can be seen that the orthogonal displacement component increases as the center of the stress relaxation hole 20 moves radially inward. In particular, it can be seen that the orthogonal displacement component in the region between the salient poles 4b of the base portion 4a increases as the hole center of the stress relaxation hole 20 moves radially inward. Thereby, as the hole center of the stress relaxation hole 20 moves inward in the radial direction, the elliptical shape after the deformation of the rotation shaft insertion hole 19 of the first rotor core 4 approaches a circle. This is because the iron weight of the regions on both sides in the circumferential direction of the stress relaxation hole 20 increases as the stress relaxation hole 20 moves inward in the radial direction, and the axial center of the first rotor core 4 and the circumferential direction of the salient pole 4b. It is assumed that the centrifugal force component perpendicular to the line connecting the center is increased.

  From FIG. 10, when the hole center of the stress relaxation hole 20 moves radially outward from the boundary between the base portion 4a and the salient pole 4b, the maximum stress value generated in the first rotor core 4 gradually increases, and the stress relaxation It can be seen that when the hole 20 is positioned within the salient pole 4b, it rapidly rises. Further, when the hole center of the stress relaxation hole 20 moves radially inward from the boundary between the base 4a and the salient pole 4b, the maximum stress value generated in the first rotor core 4 gradually decreases, and the stress relaxation hole 20 As can be seen from FIG. Therefore, the stress relaxation hole 20 is preferably formed so that the hole center is located in the base portion 4a and includes the boundary between the base portion 4a and the salient pole 4b.

  Here, when the stress relaxation hole 20 is located in the salient pole 4b, the radial width of the salient pole 4b in the radially outer region of the stress relaxation hole 20 is narrowed, and the stress is concentrated in the region of the salient pole 4b. It is assumed that the maximum stress value increased rapidly. Further, when the stress relaxation hole 20 is located in the base portion 4a, the radial width of the base portion 4a in the radially inner region of the stress relaxation hole 20 is narrowed, stress is concentrated in the region of the base portion 4a, and the maximum stress value is increased. It is thought that it rose sharply.

  According to the first embodiment, the stress relaxation hole 20 is formed so as to include the boundary between the base portions 4a, 5a and the salient poles 4b, 4b with respect to the salient poles 4b, 5b. The iron weight portions of 4b and 5b are reduced, and the centrifugal force acting on the first and second rotor cores 4 and 5 during high-speed rotation is reduced.

  Further, the stress relaxation hole 20 includes a boundary between the base portions 4a and 5a and the salient poles 4b and 4b, and is symmetrical with respect to a plane passing through the axis of the rotary shaft 2 and the circumferential center of the salient poles 4b and 5b. Since it is formed, the iron weight portions on both sides in the circumferential direction of the stress relaxation holes 20 of the salient poles 4 b and 5 b are separated in the circumferential direction with the stress relaxation holes 20 interposed therebetween. Thus, during high-speed rotation, centrifugal force acts in a direction passing from the axis of the rotating shaft 2 through the center of gravity of the iron weight portion. As a result, the centrifugal force component perpendicular to the line segment connecting the axis of the rotating shaft 2 and the center in the circumferential direction of the salient poles 4b and 5b increases, and the inner circumference of the base portions 4a and 5a is an elliptical shape close to a circle. Stress acting on the first and second rotor cores 4 and 5 acts on the first and second rotor cores 4 and 5. Therefore, the stress is uniformly distributed in the portion between the salient poles 4b and 5b of the base portions 4a and 5a, and the stress concentration is relaxed.

Thus, the rigidity of the rotor 3 can be increased by increasing the diameter of the rotating shaft 2 without increasing the outer diameter of the first and second rotor cores 4, 5, thereby increasing the dangerous rotational speed. Can do. Furthermore, since the outer diameters of the first and second rotor cores 4 and 5 are not increased, the inertia can be reduced.
Therefore, the high-speed rotating motor 1 is small and excellent in centrifugal force resistance, and can be applied to an electric supercharger motor for automobiles that requires high-speed rotation of about 200,000 rpm.

  In the first embodiment, it is assumed that the stress relaxation hole 20 is formed in a radially outwardly convex cross-sectional shape that is configured by a part of an elliptic curve whose outer peripheral side has a long axis as a circumferential direction. However, the cross-sectional shape of the stress relaxation hole 20 is not limited to this. In other words, the stress relaxation hole 20 has a non-circular cross-sectional shape that protrudes radially outward, includes the axis O of the first and second rotor cores 4 and 5, and the circumferential direction of the salient poles 4b and 5b. What is necessary is just to be formed in the hole shape symmetrical with respect to the plane which passes through the center, for example, the substantially triangular shape with which the corner | angular part was rounded may be sufficient.

Embodiment 2. FIG.
FIG. 11 is a front view showing a rotor core in a rotor of a high-speed rotary electric motor according to Embodiment 2 of the present invention.

In FIG. 11, the first and second rotor cores 4 </ b> A and 5 </ b> A are regions in which two circular stress relaxation holes 21 are separated from each other in the circumferential direction and include boundaries between the base portions 4 a and 5 a and the salient poles 4 b and 5 b. The circumferential width θ3 is 45 °. Further, the two stress relaxation holes 20 are formed symmetrically with respect to a plane including the axis O and passing through the circumferential center of the salient poles 4b and 5b.
Other configurations are the same as those in the first embodiment.

Therefore, the second embodiment also has the same effect as the first embodiment.
According to the second embodiment, since the two stress relaxation holes 21 are formed in a region including the boundary between the base portions 4a and 5a and the salient poles 4b and 5b separated in the circumferential direction, the magnetic path is a stress relaxation hole. It is ensured between 20 and the output of the high-speed rotating motor can be increased.
Moreover, since the hole shape of the stress relaxation hole 21 is circular, drilling is facilitated.

Here, in the second embodiment, the cross-sectional shape of the stress relaxation hole 21 is circular. However, the cross-sectional shape of the stress relaxation hole is not limited to a circular shape. For example, the stress relaxation hole 21 protrudes outward in the circumferential direction of the salient pole. A semicircular shape or a substantially triangular shape with rounded corners may be used.
In the second embodiment, two stress relaxation holes 21 are formed for each of the salient poles 4b and 5b. However, the number of the stress relaxation holes 21 is not limited to two. It may be more than one. In this case, the stress relaxation holes 21 are spaced apart from each other in the circumferential direction, include the boundary between the base portions 4a and 5a and the salient poles 4b and 5b, and pass through the axis O and the circumferential center of the salient poles 4b and 5b. Need only be formed symmetrically.

In each of the above embodiments, the ratio between the number of field poles and the number of slots is 4: 6, that is, the pole slot ratio is 2: 3. However, the pole slot ratio is not limited to 2: 3. For example, 4: 3 may be used.
In each of the above embodiments, one or two stress relaxation holes are formed in each salient pole. However, three or more stress relaxation holes may be formed in each salient pole. In this case, each stress relaxation hole may be formed in each salient pole so as to be symmetrical with respect to a plane including the boundary between the base and the salient pole and passing through the axial center and the circumferential center of the salient pole.

In each of the above embodiments, the stator coil is wound around the first and second stator cores by the concentrated winding method, but the stator coil is distributed by the first and second fixed winding methods. It may be wound around the child core.
In each of the above embodiments, the outer diameter of the partition is the same as the outer diameter of the first and second rotor cores. However, the outer diameter of the partition is not necessarily the same as that of the first and second rotor cores. It is not necessary to match the outer diameter. Furthermore, the partition may be omitted if the first and second rotor cores are sufficiently fixed to the rotation shaft.

  In each of the above embodiments, the first and second stator cores and the first and second rotor cores are made by laminating magnetic steel plates as magnetic thin plates, but the magnetic thin plates are magnetic. For example, an electromagnetic steel plate may be used. In addition, the first and second stator cores and the first and second rotor cores may be made of a bulk magnetic material, for example, made by insulating permalloy powder, pressing and heat-treating it. A compacted iron core can be used.

  In each of the above-described embodiments, the rotor is configured by fixing two rotor cores formed in the same shape to the rotating shaft coaxially with a half salient pole pitch shifted in the circumferential direction. However, even if the present invention is applied to a rotor configured by fixing one rotor core coaxially to the rotation shaft, the same effect can be obtained. A rotor formed by coaxially fixing one rotor core to a rotation shaft can be applied to a rotor of a switched reluctance motor, for example.

  DESCRIPTION OF SYMBOLS 1 Rotating motor, 2 Rotating shaft, 3 Rotor, 4, 4A 1st rotor core, 4a base, 4b Salient pole, 5, 5A 2nd rotor core, 5a Base, 5b Salient pole, 7 Stator, 8 Fixed Child core, 9 first stator core, 9a core back, 9b teeth, 9c slot, 10 second stator core, 10a core back, 10b teeth, 10c slot, 11 stator coil, 12 field coil (field means) ), 13 Housing (magnetic path forming member), 20, 21 Stress relaxation holes.

Claims (6)

A rotation axis;
A cylindrical base fixed coaxially to the rotation shaft, and a rotor core having a plurality of salient poles disposed in the circumferential direction at an equiangular pitch and extending in the axial direction on the outer peripheral surface of the base. ,
A stress relaxation hole corresponds to each of the salient poles, includes a boundary between the base and the salient poles, and is symmetric with respect to a plane passing through the axis of the rotating shaft and the circumferential center of the salient poles. A rotor for a high-speed rotary electric motor, wherein the rotor core is formed so as to penetrate the rotor core in the axial direction. The rotor core has two salient poles,
2. The rotor for a high-speed rotary electric motor according to claim 1, wherein one stress relaxation hole is formed for each of the salient poles. The rotor core has two salient poles,
The rotor for a high-speed rotary motor according to claim 1, wherein the stress relaxation holes correspond to each of the salient poles and are formed two by two apart from each other in the circumferential direction. The teeth that define the slots that open to the inner peripheral side project radially inward from the inner peripheral surface of the cylindrical core back, and are formed in the same shape in which a plurality of teeth are arranged in the circumferential direction. The stator core and the second stator core are wound around the stator core and the stator core, which are configured to be separated from each other by a predetermined distance in the axial direction and coaxially arranged so that the circumferential positions of the teeth coincide with each other. A stator having a stator coil mounted thereon;
The first rotor core and the second rotor core manufactured in the same shape in which the salient poles are arranged on the outer peripheral surface of the cylindrical base portion at an equiangular pitch in the circumferential direction are respectively referred to as the first stator core and A rotor positioned on the inner peripheral side of the second stator core and arranged with a half salient pole pitch in the circumferential direction, and coaxially fixed to a rotation shaft inserted through the base;
Field means disposed on the stator and generating field magnetic flux so that the salient poles of the first rotor core and the salient poles of the second rotor core have different polarities;
An axial magnetic path forming member extending in the axial direction so as to connect the core back outer peripheral surface of the first stator core and the core back outer peripheral surface of the second stator core;
The stress relaxation hole has a symmetrical shape with respect to each of the salient poles, including a boundary between the base and the salient poles, and passing through the axis of the rotating shaft and the circumferential center of the salient poles. And a high-speed rotary electric motor formed so as to penetrate the first rotor core and the second rotor core in the axial direction. The first rotor core and the second rotor core each have two salient poles,
The high-speed rotary electric motor according to claim 4, wherein one stress relaxation hole is formed for each of the salient poles. The first rotor core and the second rotor core each have two salient poles,
5. The high-speed rotary electric motor according to claim 4, wherein the stress relaxation holes correspond to each of the salient poles and are formed two by two apart in the circumferential direction.

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