WO2021019692A1 - Machine électrique rotative - Google Patents

Machine électrique rotative Download PDF

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Publication number
WO2021019692A1
WO2021019692A1 PCT/JP2019/029865 JP2019029865W WO2021019692A1 WO 2021019692 A1 WO2021019692 A1 WO 2021019692A1 JP 2019029865 W JP2019029865 W JP 2019029865W WO 2021019692 A1 WO2021019692 A1 WO 2021019692A1
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WIPO (PCT)
Prior art keywords
rotor
slit
electric machine
magnet
rotary electric
Prior art date
Application number
PCT/JP2019/029865
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English (en)
Japanese (ja)
Inventor
甲彰 山根
純士 北尾
朋平 高橋
義浩 深山
裕輔 木本
Original Assignee
三菱電機株式会社
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
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Publication date
Application filed by 三菱電機株式会社 filed Critical 三菱電機株式会社
Priority to PCT/JP2019/029865 priority Critical patent/WO2021019692A1/fr
Priority to JP2020549723A priority patent/JP7126557B2/ja
Publication of WO2021019692A1 publication Critical patent/WO2021019692A1/fr

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    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02K—DYNAMO-ELECTRIC MACHINES
    • H02K1/00—Details of the magnetic circuit
    • H02K1/06—Details of the magnetic circuit characterised by the shape, form or construction
    • H02K1/22—Rotating parts of the magnetic circuit
    • H02K1/27—Rotor cores with permanent magnets

Definitions

  • This application relates to a rotary electric machine.
  • a magnet insertion hole for embedding a permanent magnet is formed in the rotor of this rotary electric machine, and a bridge portion is formed between the outer peripheral surface of the rotor core and the magnet insertion hole.
  • Patent Document 1 a configuration in which a slit is formed between permanent magnets having different magnetic poles is disclosed.
  • JP-A-2010-178471 paragraphs [0008], [0018], [0029] and FIGS. 1, 2)
  • the present application has been made to solve the above-mentioned problems, and obtains a rotary electric machine capable of improving the durability of the rotor core by reducing the stress of the bridge portion while suppressing the torque decrease of the rotary electric machine.
  • the purpose is.
  • the rotary electric machine disclosed in the present application is a rotary electric machine including a stator having an armature winding and a rotor that rotates on the inner circumference of the stator.
  • a plurality of permanent magnets forming magnetic poles are formed in the axial direction of the core.
  • Each magnetic pole is composed of two or more permanent magnets, and each magnetic pole is cut into the outer peripheral iron part surrounded by the permanent magnet and the outer peripheral surface of the rotor from the outer peripheral surface of the rotor inward in the radial direction of the rotor. It is provided with a sloping slit, and has a gap portion having a width in the circumferential direction larger than the width in the circumferential direction of the slit at the tip inside the radial direction of the slit.
  • FIG. 5 is a plan view of the rotor of the rotary electric machine according to the first embodiment as viewed from the axial direction.
  • FIG. 5 is an enlarged plan view of one pole of the rotor of the rotary electric machine according to the first embodiment.
  • It is a top view of the comparative example for demonstrating the acting stress mechanism in the rotor of the rotary electric machine according to Embodiment 1.
  • FIG. It is a top view of the comparative example for demonstrating the acting stress mechanism in the rotor of the rotary electric machine according to Embodiment 1.
  • FIG. 1 It is a top view for demonstrating the acting stress mechanism in the rotor of the rotary electric machine according to Embodiment 1.
  • FIG. It is a top view for demonstrating the path of the magnet magnetic flux and the reluctance magnetic flux in the rotor of the rotary electric machine according to Embodiment 1.
  • FIG. It is explanatory drawing of the definition of the slit shape and the length in the rotor of the rotary electric machine according to Embodiment 1.
  • FIG. It is explanatory drawing of the definition of the slit of the rotor of the comparative example for demonstrating the effect of the rotary electric machine by Embodiment 1.
  • FIG. 5 is an enlarged plan view of one pole of the rotor of the rotary electric machine according to the second embodiment. It is a top view for demonstrating the path of the magnet magnetic flux and the reluctance magnetic flux in the rotor of the rotary electric machine according to Embodiment 2.
  • FIG. 5 is an enlarged plan view of one pole of the rotor of the rotary electric machine according to the third embodiment.
  • FIG. 5 is an enlarged plan view of the periphery of the magnet insertion hole of the rotor of the rotary electric machine according to the third embodiment.
  • FIG. 5 is an enlarged plan view of one pole of the rotor of the rotary electric machine according to the fourth embodiment.
  • the first embodiment includes a stator having an armature winding and a rotor that rotates on the inner circumference of the stator, and a magnet insertion hole through which a plurality of permanent magnets constituting magnetic poles penetrate in the axial direction of the core of the rotor.
  • Each magnetic pole is composed of two permanent magnets, and each magnetic pole is provided with a slit cut inward in the radial direction from the outer peripheral surface of the rotor to the outer peripheral iron portion surrounded by the permanent magnet and the outer peripheral surface of the rotor. It relates to a rotary electric machine having a gap at the tip on the inner side in the radial direction.
  • FIG. 1 which is a vertical sectional view schematically showing the configuration of the rotary electric machine
  • FIG. 2 which is a plan view of the rotor viewed from the axial direction, and one pole of the rotor.
  • FIG. 3 which is an enlarged plan view of FIG. 3,
  • FIG. 4 which is a plan view of a comparative example for explaining the acting stress mechanism in the rotor
  • FIG. 6 which is a plan view for explaining the acting stress mechanism in the rotor.
  • FIG. 7 is a plan view for explaining the paths of magnet magnetic flux and reluctance magnetic flux in the rotor
  • FIG. 1 which is a vertical sectional view schematically showing the configuration of the rotary electric machine
  • FIG. 2 which is a plan view of the rotor viewed from the axial direction, and one pole of the rotor.
  • FIG. 3 which is an enlarged plan view of FIG. 3
  • FIG. 4 which is a plan view of a comparative example for explaining the acting stress mechanism in the rotor
  • FIG. 8 is an explanatory view of the definition of the slit shape and the length in the rotor, and the definition of the slit in the comparative example for explaining the effect.
  • 9 is an explanatory view of FIG. 9
  • FIG. 10 is an explanatory view of stress acting on the outer peripheral bridge and the slit of a comparative example for explaining the effect
  • FIG. 11 is an explanatory view of the stress acting on the outer peripheral bridge and the slit of the rotor.
  • FIG. 12 which is a plan view of a modified example of the rotor, will be described.
  • each direction in the rotary electric machine 100 is shown as an axial direction G, a circumferential direction S, and a radial direction K, respectively. Therefore, in other parts as well, each direction will be described with reference to these directions. Further, in the second and subsequent embodiments, each direction is similarly shown.
  • the rotary electric machine 100 includes a stator 1 and a rotor 2.
  • the stator 1 includes a stator core 6 in which a plurality of steel plates are laminated in the axial direction, and a coil 7 wound around the stator core 6.
  • the rotor 2 is composed of a rotor core 3, a permanent magnet 4 embedded in the rotor core 3, and a shaft 5 penetrating the inner peripheral portion of the rotor core 3.
  • the permanent magnet 4 is divided into a plurality of pieces in the axial direction.
  • the rotor core 3 and the shaft 5 are press-fitted and shrink-fitted, or fitted via a key structure provided on the inner circumference of the rotor core 3 and the outer circumference of the shaft 5.
  • the axial direction of the rotary electric machine 100 is represented by G.
  • FIG. 2 is a plan view of the rotor 2 of the rotary electric machine 100 as viewed from the axial direction.
  • the circumferential direction of the rotary electric machine 100 that is, the circumferential direction of the rotor 2
  • the radial direction of the rotary electric machine 100 that is, the radial direction of the rotor 2
  • Twenty-four magnet insertion holes 21 are arranged in the rotor core 3 at intervals in the circumferential direction, and permanent magnets 4 are embedded in each of the magnet insertion holes 21.
  • the magnet insertion hole 21 and the permanent magnet 4 form a set of two magnets adjacent to each other in the circumferential direction, forming 12 V-shapes extending from the center side of the rotation axis toward the outside in the radial direction.
  • One magnetic pole is composed of two V-shaped magnet insertion holes 21 and two permanent magnets 4, and 12 magnetic poles are arranged side by side in the circumferential direction.
  • FIG. 3 is an enlarged plan view of one magnetic pole of the rotor 2.
  • the thin-walled portion formed by being sandwiched between the magnet insertion hole 21 and the rotor outer peripheral surface 20 of the rotor core 3 is referred to as the outer peripheral bridge portion 22.
  • a thin-walled portion sandwiched between two magnet insertion holes 21 (21a, 21b) forming a V-shape, which is a central portion in the circumferential direction of the V-shape and is formed inside in the radial direction is referred to as a central bridge portion 23.
  • the portion sandwiched between the magnetic poles is defined as the magnetic pole spacing 28.
  • the triangular portion surrounded by the two magnet insertion holes 21 (21a, 21b) and the rotor outer peripheral surface 20 is referred to as the outer peripheral iron portion 24.
  • the magnet insertion holes 21 are appropriately described.
  • a slit 25 is formed in the outer peripheral iron portion 24.
  • the slit 25 includes an extension portion 251 extending inward in the radial direction from the rotor outer peripheral surface 20 and a gap portion 252.
  • the extending portion 251 is arranged so as to extend in the radial direction through the center of the magnetic pole.
  • the gap portion 252 is located at the tip of the slit 25 on the inner side in the radial direction, and has a width in the circumferential direction larger than the minimum width in the circumferential direction of the extension portion 251.
  • the gap portion 252 is assumed to have an arc shape, but may be a quadrangle or a polygon.
  • FIG. 4 is a diagram for explaining the outline of the load acting on the rotor 2 of Comparative Example 1, that is, the acting stress mechanism.
  • the rotor 2A, the rotor core 3A, the outer peripheral bridge portion 22A, and the outer peripheral iron portion 24A are described.
  • the arrow E indicates the direction in which the outer peripheral iron portion 24 moves in response to the centrifugal force.
  • stress (P, Q) is generated in the outer peripheral bridge portion 22A by the following two mechanisms in the rotor core 3A.
  • the entire rotor core 3A swells in the radial direction due to centrifugal force, and the length in the circumferential direction increases, so that the circumferential tensile stress generated in the outer peripheral portion and the inner peripheral portion including the outer peripheral bridge portion 22A ( P).
  • the other is the bending stress (Q) locally generated in the outer peripheral bridge portion 22A when the outer peripheral iron portion 24A protrudes in the radial direction due to the centrifugal force in FIG. Due to this bending stress (Q), the outer peripheral bridge portion 22A undergoes bending deformation that becomes convex inward in the radial direction.
  • FIG. 5 is a diagram for explaining the outline of the load acting on the rotor 2B of Comparative Example 2, that is, the acting stress mechanism. In order to distinguish it from the rotor 2 and the like of the first embodiment, it is described as a rotor 2B, a rotor core 3B, an outer peripheral bridge portion 22B, an outer peripheral iron portion 24B, and a slit 25B.
  • the circumferential tensile stress (P) generated in the inner peripheral portion and the bending stress (Q) locally generated in the outer peripheral bridge portion 22B described in FIG. 4 are the same as in the rotor 2A of Comparative Example 1. Occurs. As will be described with reference to FIG. 6, the circumferential tensile stress (P) generated in the outer peripheral portion including the outer peripheral bridge portion 22B is reduced.
  • a stress (R) acts on the slit 25B because the outer peripheral iron portion 24B protrudes outward in the radial direction due to the action of centrifugal force.
  • the outer peripheral iron portion 24A protrudes outward in the radial direction due to the action of centrifugal force, but the stress (R) does not work because there is no slit.
  • the slits 25 and 25B provided together hinder the transmission of the tensile stress (P) in the circumferential direction shown in the first comparative example, so that the outer peripheral bridge portions 22 and 22B The stress can be reduced.
  • the position where the slit 25 is provided will be examined. It is conceivable that the slit 25 for reducing the stress acting on the outer peripheral bridge portion 22 is provided not in the outer peripheral iron portion 24 but in the magnetic poles 28 sandwiched between the magnetic poles.
  • the magnet torque generated by the magnet magnetic flux from the permanent magnet and the reluctance magnetic flux due to the magnetoresistance of the rotor core are used. Two types of torque can be obtained, the reluctance torque generated.
  • the final torque of the rotary electric machine is the combined torque of the two types of torque.
  • FIG. 7 is an enlarged plan view of one pole of the rotor 2 of the first embodiment, in which a magnet magnetic flux and a reluctance magnetic flux are added.
  • the magnet magnetic flux is described as MF and the reluctance magnetic flux is described as RF, and the width of the magnetic poles 28 is 28 W.
  • some reference numerals are omitted with respect to FIG.
  • the reluctance magnetic flux passes between the magnetic poles 28, if a slit is provided between the magnetic poles 28, the width 28 W between the magnetic poles becomes narrow and the path of the reluctance magnetic flux is obstructed. Therefore, the reluctance torque itself is lowered, so that the final torque is lowered.
  • the slit 25 is provided in the outer peripheral iron portion 24, it is possible to prevent a decrease in the reluctance torque, and as a result, it is possible to prevent a final decrease in torque. That is, according to the first embodiment, the stress generated in the rotor core 3 can be reduced without lowering the maximum torque of the rotary electric machine 100, and the durability of the rotor core 3 can be improved.
  • the tensile stress in the circumferential direction generated on the inner circumference of the core due to the centrifugal force is concentrated on the slit end portion on the inner side in the radial direction, so that it is necessary to provide a gap portion at the slit end portion.
  • the inner peripheral area of the core that receives tensile stress in the circumferential direction is reduced. Therefore, the stress acting on the inner circumference of the rotor core increases. Therefore, the inner peripheral stress when the rotor core and the shaft are held by press fitting and the key stress when the rotor core and the shaft are held by the key structure increase.
  • the stress generated in the inner circumference of the rotor core is not directly affected.
  • FIG. 8 is an explanatory diagram of definitions of a slit shape and a length provided in the rotor core 3 of the first embodiment.
  • the magnet insertion holes 21 (21a, 21b) forming the V-shape the outer contour lines located radially outward in the circumferential direction of the permanent magnet 4 are extended and intersected at the center of the V-shape, and the V-shaped formation line 260a, It is set to 260b.
  • the V-shaped forming line 260 is described.
  • the first slit line 261 is a line that passes through the center of the extension portion 251 and is connected to the first slit line 261 at the shortest distance in the gap portion 252 starting from the radial outer side of the slit 25.
  • the point where the first slit line 261 and the second slit line 262 are connected is defined as the slit end point 27.
  • the length of the first slit line 261 is L261
  • the length of the second slit line 262 is L262.
  • the maximum position of the stress acting on the slit 25 is near the position where the magnet insertion hole 21 and the slit 25 are the shortest distance, that is, near the slit end point 27. Therefore, in the gap portion 252 of the slit 25, it is preferable that the vicinity of the slit end point 27 is a curved line or a straight line having a small curvature in order to reduce stress concentration. Specifically, if the slit end point 27 is a curve having a diameter larger than half the minimum width of the stretched portion 251, the stress acting on the slit can be reduced as compared with Comparative Example 2 described with reference to FIG. If the diameter of the curve at the slit end point 27 is increased, it becomes equivalent to a straight line parallel to the V-shaped forming line 260b.
  • the stress generated in the gap portion 252 of the slit 25 depends on the positional relationship with the magnet insertion hole 21.
  • the stress concentration portions are not at the tips of the gap portions 252 but near the slit end points 27, and are symmetrically at two locations with respect to the center of the magnetic pole.
  • a slit is provided between the magnetic poles 28, a tensile stress in the circumferential direction generated on the inner circumference of the core acts due to centrifugal force, so that the stress concentration portion becomes the tip of the slit on the inner side in the radial direction.
  • the stress generation position and the stress generation mechanism are different between the case where the slit is provided at the center of the magnetic pole and the case where the slit is provided between the magnetic poles as in the first embodiment, and the suitable construction method of the gap portion is also significantly different. ..
  • FIG. 9 shows a rotor 2B having a stretched portion 251B and a slit 25B having a radial inner tip formed by an arc having a diameter equal to the width of the stretched portion 251B, similar to the rotor 2B shown in FIG. 5 as Comparative Example 2.
  • FIG. 9 is an explanatory diagram of definitions of a slit shape and a length provided in the rotor core 3B.
  • the V-shaped forming lines 260Ba and 260Bb are formed by extending the outer contour lines extending in the circumferential direction on the radial outer side of the magnet insertion holes 21 (21a, 21b) forming the V-shape and intersecting them at the center of the V-shape.
  • the V-shaped forming line 260B When it is not necessary to distinguish the V-shaped forming line 260Ba and 260Bb, it is described as the V-shaped forming line 260B.
  • the second slit line 262B is a line that starts from the radial outer side of the slit 25B, passes through the center of the extension portion 251B, and is connected to the first slit line 261B at the tip inside the radial direction at the shortest distance.
  • the point where the first slit line 261B and the second slit line 262B are connected is defined as a slit end point 27B.
  • the length of the first slit line 261B is L261B
  • the length of the second slit line 262B is L262B.
  • FIG. 10 shows the maximum stress values generated in the outer peripheral bridge portion 22B and the slit 25B when the rotor core 3B is rotated at 13000 rpm by changing the ratio of L261B and L262B in FIG. 9 for Comparative Example 2.
  • the horizontal axis is L262B / (L261B + L262B), and the vertical axis is stress (unit: MPa).
  • the solid line represents the stress of the outer peripheral bridge portion, and the dotted line represents the stress of the slit portion.
  • FIG. 11 shows the maximum stress values generated in the outer peripheral bridge portion 22 and the slit 25 when the rotor core 3 is rotated at 13000 rpm by changing the ratio of L261 and L262 in FIG. 8 for the first embodiment.
  • the horizontal axis is L262 / (L261 + L262)
  • the vertical axis is stress (unit: MPa).
  • the solid line represents the stress of the outer peripheral bridge portion
  • the dotted line represents the stress of the slit portion.
  • the slit portion stress was lower than that of Comparative Example 2, and the value of L262 / (L261 + L262) in which the stress acting on the slit exceeded the outer peripheral bridge portion stress was 0.86. Further, when the value of L262 / (L261 + L262) was 0.86, the slit stress was 209 MPa. Therefore, in the first embodiment, the stress acting on the rotor core could be reduced by 34 MPa as compared with Comparative Example 2. That is, according to the first embodiment, the stress generated in the rotor core 3 can be reduced, and the durability of the rotor core 3 can be improved.
  • the width of the stretched portion 251 of the slit 25 can be suppressed as small as possible by using a shearing machine.
  • the steel sheet since the steel sheet may be deformed in a direction other than the plane direction, it is preferably formed by punching. Further, in the case of punching, there is an advantage that the relative positions of the slit 25 to be generated and the magnet insertion hole 21 can be kept constant. Further, there is an advantage that mass productivity is not impaired.
  • the slit 25 when the slit 25 is formed by punching, the slit 25 has a certain width.
  • the magnet magnetic flux generated by the permanent magnet 4 passes through the outer peripheral iron portion 24, magnetic saturation does not occur in the outer peripheral iron portion 24 of the stretched portion 251 of the slit 25 in order to secure a magnetic path of the magnet magnetic flux and prevent magnetic saturation. It is preferable to make it as thin as possible.
  • the non-magnetic material may be filled in a region other than the region occupied by the permanent magnet 4 in the magnet insertion hole 21.
  • filling with resin has the effect of preventing the permanent magnet 4 from moving due to centrifugal force and torque fluctuation.
  • filling with a heat radiating material has the effect of improving the temperature rise of the magnet.
  • the number, shape, position, etc. of the permanent magnets 4 forming each magnetic pole may be changed. For example, even when the number of permanent magnets of each magnetic pole is three as shown in FIG. 12, which is a plan view of a modified example of the rotor of the rotary electric machine according to the first embodiment, the same effect as that of the rotor 2 of FIG. 3 can be obtained.
  • the number of permanent magnets is not limited to two or three, and may be four or more.
  • the rotary electric machine of the first embodiment includes a stator having an armature winding and a rotor that rotates on the inner circumference of the stator, and the core of the rotor is composed of a plurality of permanent magnets forming magnetic poles.
  • Each magnetic pole is composed of two permanent magnets, and each magnetic pole is cut inward from the outer peripheral surface of the rotor to the outer peripheral iron part surrounded by the permanent magnet and the outer peripheral surface of the rotor. It is provided with a recessed slit, and has a gap at the tip inside the radial direction of the slit. Therefore, the rotary electric machine of the first embodiment can reduce the stress of the bridge portion, suppress the torque decrease, and improve the durability of the rotor core.
  • Embodiment 2 In the rotary electric machine of the second embodiment, in the cross section of the rotor perpendicular to the axial direction of the rotary electric machine, the angle of the slit cut inward in the radial direction of the rotor is tilted in the circumferential direction with respect to the radial direction of the rotor. It is a thing.
  • FIG. 13 is an enlarged plan view of one pole of the rotor
  • FIG. 14 is a plan view for explaining the path of the magnet magnetic flux and the reluctance magnetic flux in the rotor, and a modification of the rotor.
  • FIGS. 15 to 18 are plan views.
  • FIGS. 13-18 of the second embodiment the same or corresponding parts as those of the first embodiment are designated by the same reference numerals.
  • the rotary electric machine 200 is used.
  • the overall configuration of the rotor 2 of the second embodiment is the same as that of FIG. 2 of the first embodiment. That is, 24 magnet insertion holes 21 are arranged in the rotor core 3 at intervals in the circumferential direction, and permanent magnets 4 are embedded in each of the magnet insertion holes 21.
  • the magnet insertion hole 21 and the permanent magnet 4 form a set of two adjacent magnets in the circumferential direction, forming 12 V-shapes extending from the center side of the rotation axis toward the outside in the radial direction.
  • One magnetic pole is composed of two V-shaped magnet insertion holes 21 and two permanent magnets 4, and 12 magnetic poles are arranged side by side in the circumferential direction.
  • FIG. 13 is an enlarged plan view of the one pole of the rotor 2.
  • the thin-walled portion formed by being sandwiched between the magnet insertion hole 21 and the rotor outer peripheral surface 20 of the rotor core 3 is referred to as the outer peripheral bridge portion 22.
  • a thin-walled portion sandwiched between two magnet insertion holes 21 (21a, 21b) forming a V-shape, which is a central portion in the circumferential direction of the V-shape and is formed inside in the radial direction is referred to as a central bridge portion 23.
  • the triangular portion surrounded by the two magnet insertion holes 21 (21a, 21b) and the rotor outer peripheral surface 20 is referred to as the outer peripheral iron portion 24.
  • a slit 25 is formed in the outer peripheral iron portion 24.
  • the slit 25 has a stretched portion 251 extending from the outer peripheral surface 20 of the rotor inward in the radial direction, and a gap portion 252 having a width in the circumferential direction larger than the circumferential width of the stretched portion 251 at the tip on the inner side in the radial direction.
  • the stretched portion 251 is arranged in the circumferential direction with respect to the radial direction.
  • the tensile stress in the circumferential direction acting on the outer peripheral bridge portion 22 can be reduced by the slit 25 as in the first embodiment. Therefore, also in the second embodiment, the stress generated in the rotor core 3 can be reduced, and the durability of the rotor core 3 can be improved.
  • FIG. 14 is an enlarged plan view of one pole of the rotor 2 of the second embodiment, in which a magnet magnetic flux and a reluctance magnetic flux are added.
  • the magnet magnetic flux is described as MF and the reluctance magnetic flux is described as RF.
  • some reference numerals are omitted with respect to FIG.
  • the slits 25 by arranging the slits 25 asymmetrically with respect to the magnetic poles, it is possible to generate a path of the reluctance magnetic flux in the outer peripheral iron portion 24 as shown in FIG. Due to the reluctance torque generated by the path of the reluctance magnetic flux, the rotation phase angle at which the reluctance torque peaks can be shifted from the phase angle of a general rotating electric machine.
  • the magnetic flux of the magnet can also be unevenly distributed to one side by the slit 25. Therefore, the rotation phase angle at which the magnet torque reaches the peak value can also be shifted from the phase angle of a general rotating electric machine. Therefore, the rotation phase angle of the rotor 2 at which the magnet torque and the reluctance torque have peak values can be designed to be close to each other, and the final torque can be improved.
  • the outer peripheral iron portion 24 divided into two by the slit 25 if there is a magnetic path through which magnetic flux leaks in both of the divided areas, the final amount of increase in torque decreases. That is, in order to increase the torque, it is necessary to narrow the magnetic path formed between the magnet insertion hole 21 and the slit 25.
  • the length of the slit 25 can be increased and the magnetic path formed between the slit 25 and the magnet insertion hole 21 can be narrowed as compared with the case of the oblique slit having no gap. Therefore, the leakage flux generated in the outer peripheral iron portion 24 divided into two can be reduced, and the final torque can be improved as compared with the case of the oblique slit having no gap portion.
  • each of the plurality of magnet insertion holes 21 constituting each magnetic pole may have a different shape.
  • the size of each of the plurality of permanent magnets 4 constituting each magnetic pole may be changed.
  • the rotor 2 shown in FIG. 15 has an effect of reducing the imbalance of stress generated in the magnet insertion hole by forming the slit 25 at an angle, by making each of the magnet insertion holes into a different shape.
  • the magnet magnetic flux interlinking with the stator can be adjusted in the circumferential direction by changing the size of each of the plurality of permanent magnets 4.
  • the shape of the extended portion 251 of the slit 25 does not have to be a straight line.
  • the rotor of the rotary electric machine of the second embodiment has a curve that is concave outward in the radial direction as shown in FIG. 17 of the third modification, or is convex outward in the radial direction as shown in FIG. 18 of the modification 4. It may be curved.
  • the stretched portion 251 of the slit 25 in a non-linear manner, that is, by bending it, it is possible to prevent the magnetic flux of the magnet from being magnetically saturated, and by adjusting the left and right areas of the outer peripheral iron portion divided by the slit 25. The bending stress acting on the outer peripheral bridge portion 22 can be adjusted.
  • the angle of the slit cut inward in the radial direction of the rotor is set with respect to the radial direction of the rotor. It is tilted in the circumferential direction. Therefore, the rotary electric machine of the second embodiment can reduce the stress at the bridge portion, suppress the torque decrease, and improve the durability of the rotor core. In addition, the final torque can be improved.
  • Embodiment 3 The rotary electric machine of the third embodiment has a configuration in which the radial side of the permanent magnet embedded in the rotor is held on the radial outside of the rotor core against the centrifugal force during rotation of the rotor.
  • FIG. 19 which is an enlarged plan view of one pole of the rotor
  • FIG. 20 which is an enlarged plan view of the periphery of the magnet insertion hole of the rotor, and the structure around the magnet insertion hole of the rotor of the rotary electric machine of the third embodiment.
  • 21 is an explanatory view of the above
  • FIG. 22 is an explanatory view of the stress relaxation hole and the refrigerant path of the rotor
  • FIG. 23 is an explanatory view of a comparative example for explaining the effect
  • an explanatory view of the centrifugal force action of the rotor The difference from the first embodiment will be mainly described with reference to FIG. 24.
  • FIGS. 19 to 24 of the third embodiment the same or corresponding parts as those of the first embodiment are designated by the same reference numerals.
  • the rotary electric machine 300 is used.
  • the overall configuration of the rotor 2 of the third embodiment is the same as that of FIG. 2 of the first embodiment. That is, 24 magnet insertion holes 21 are arranged in the rotor core 3 at intervals in the circumferential direction, and permanent magnets 4 are embedded in each of the magnet insertion holes 21.
  • the magnet insertion hole 21 and the permanent magnet 4 form a set of two adjacent magnets in the circumferential direction, forming 12 V-shapes extending from the center side of the rotation axis toward the outside in the radial direction.
  • One magnetic pole is composed of two V-shaped magnet insertion holes 21 and two permanent magnets 4, and 12 magnetic poles are arranged side by side in the circumferential direction.
  • FIG. 19 is an enlarged plan view of the one pole of the rotor 2.
  • the thin-walled portion formed by being sandwiched between the magnet insertion hole 21 and the rotor outer peripheral surface 20 of the rotor core 3 is referred to as the outer peripheral bridge portion 22.
  • a thin-walled portion sandwiched between two magnet insertion holes 21 (21a, 21b) forming a V-shape, which is a central portion in the circumferential direction of the V-shape and is formed inside in the radial direction is referred to as a central bridge portion 23.
  • the triangular portion surrounded by the two magnet insertion holes 21 (21a, 21b) and the rotor outer peripheral surface 20 is referred to as the outer peripheral iron portion 24.
  • a slit 25 is formed in the outer peripheral iron portion 24.
  • the slit 25 includes an extension portion 251 extending inward in the radial direction from the rotor outer peripheral surface 20 and a gap portion 252.
  • the extending portion 251 is arranged so as to extend in the radial direction through the center of the magnetic pole.
  • the gap portion 252 is located at the tip of the slit 25 on the inner side in the radial direction, and has a width in the circumferential direction larger than the minimum width in the circumferential direction of the extension portion 251.
  • FIG. 20 is an enlarged plan view of the periphery of the magnet insertion hole of the rotor.
  • the surface that holds the outer side in the circumferential direction of the permanent magnet is designated as the first magnet holding surface 211.
  • the surface that holds the radial direction of the permanent magnet is the second magnet holding surface 212.
  • the surface in the circumferential direction of the permanent magnet held by the first magnet holding surface 211 is referred to as the first magnet surface 31.
  • the radial surface of the permanent magnet held by the second magnet holding surface 212 is referred to as the second magnet surface 32.
  • a space is provided between the first magnet holding surface 211 and the first magnet surface 31 and between the second magnet holding surface 212 and the second magnet surface 32 for easy understanding. However, they are actually in close contact.
  • the magnet is inserted so that the central portion (point d) of the second magnet holding surface 212 is closer to the first magnet holding surface 211 than the central portion (point e) of the second magnet surface 32.
  • the hole 21 is formed. That is, in the third embodiment, the radial end face side of the permanent magnet 4 is held on the radial outside of the rotor core 3. On the other hand, in the first embodiment, as is clear from FIG. 3, the radial end face side of the permanent magnet 4 is held inside the rotor core 3 in the radial direction.
  • the tensile stress in the circumferential direction acting on the outer peripheral bridge portion 22 can be reduced by the slit 25 as in the first embodiment. Therefore, also in the third embodiment, the stress generated in the rotor core 3 can be reduced, and the durability of the rotor core 3 can be improved.
  • FIG. 21 is a diagram for comparison showing the structure around the magnet insertion hole in the rotor of the rotary electric machine according to the first embodiment.
  • FIG. 22 is a diagram showing a structure around a magnet insertion hole in the rotor of the rotary electric machine according to the third embodiment.
  • the second magnet holding surface 212 receives a force from the permanent magnet 4 that tends to scatter in the radial outward direction (positive direction), so that the stress relaxation holes 213 are formed as shown in FIGS. 21 and 22. Need to be provided. That is, in FIG. 21, the stress relaxation hole 213 is provided inside the rotor core 3 in the radial direction. On the other hand, in FIG. 22, stress relaxation holes 213 are provided on the outer side in the radial direction of the rotor core 3.
  • the stress relaxation hole 213 of the first embodiment shown in FIG. 21 is on the path of the reluctance magnetic flux shown in FIG. 7, the angle formed by the circumferential direction of the permanent magnet 4 and the radial direction of the rotor core 3 is small. In the case where the rotation speed is large and the stress relaxation hole 213 is large, the reluctance magnetic flux is hindered and the reluctance torque is reduced. On the other hand, when the stress relaxation holes 213 of the third embodiment shown in FIG. 22 are held outside the radial direction of the permanent magnet 4, the stress relaxation holes 213 do not hinder the reluctance magnetic flux, so that the reluctance torque is reduced. Can be prevented.
  • the second is that the cooling effect of permanent magnets can be enhanced.
  • the refrigerant inlet hole 214 is provided on the surface of the magnet insertion hole 21 running parallel to the radial inner surface of the permanent magnet 4 in the circumferential direction.
  • Refrigerant is supplied to the refrigerant inlet hole 214 from the end in the rotor axial direction.
  • the supplied refrigerant flows in the direction of the arrow (L) shown in FIG. 22 through the gap formed between the magnet insertion hole 21 and the permanent magnet 4 by centrifugal force.
  • the refrigerant collects in the refrigerant outlet hole 215 located on the radial outer side of the magnet insertion hole 21 and is discharged from the rotor axial end. In this way, the circumferential direction and the radial direction of the permanent magnet 4 can be efficiently cooled at the same time, and demagnetization of the permanent magnet 4 can be prevented.
  • FIG. 23 is a view as a comparative example 3 in which the deformed shape when a centrifugal force acts on a rotor core having a structure in which the outer peripheral iron portion has no slit and holds a permanent magnet on the outer side in the radial direction is magnified 120 times.
  • FIG. 23 is a view as a comparative example 3 in which the deformed shape when a centrifugal force acts on a rotor core having a structure in which the outer peripheral iron portion has no slit and holds a permanent magnet on the outer side in the radial direction is magnified 120 times.
  • the rotor 2C, the rotor core 3C, the outer peripheral bridge portion 22C, the outer peripheral iron portion 24C, the quasi-outer peripheral bridge portion 29C, and the second magnet holding surface 212C are described. doing.
  • F represents the force that the permanent magnet 4 acts on the second magnet holding surface 212C due to the centrifugal force.
  • the tensile stress generated by the increase in the circumferential length of the outer peripheral bridge portion 22C and the outer peripheral iron portion 24C projecting in the radial outward direction (positive direction) causes a convex bending deformation in the radial direction.
  • the generated bending stress acts.
  • S is "pull in the circumferential direction + bending convex inward in the radial direction”.
  • the reaction force of the force for holding the permanent magnet 4 acts on the second magnet holding surface 212C toward the outer periphery in the normal direction of the second magnet holding surface 212C.
  • the quasi-outer peripheral bridge portion 29C which has a thickness larger than that of the outer peripheral bridge portion 22C in order to connect with the outer peripheral bridge portion 22C to form the second magnet holding surface 212C, is locally bent outward in the radial direction. Deformation occurs. As a result, the tensile stress generated by the increase in the circumferential length and the bending stress generated by the radial outward convex bending deformation act on the quasi-outer peripheral bridge portion 29C. T is "pull in the circumferential direction + bending outward in the radial direction".
  • outer peripheral bridge portion 22C has a stress concentration portion on the inner peripheral side of the bridge
  • quasi-outer peripheral bridge portion 29C has a stress concentration portion on the outer peripheral side of the bridge.
  • FIG. 24 shows a deformed shape when a centrifugal force acts on a rotor core 3 having a structure in which a slit 25 is provided in the outer peripheral iron portion 24 and the permanent magnet 4 is held on the outer side in the radial direction as the third embodiment. Is magnified 120 times.
  • the transmission of the tensile stress in the circumferential direction acting on the rotor core 3C of the comparative example 3 is hindered. Therefore, since only bending stress mainly acts on the outer peripheral bridge portion 22 and the quasi-outer peripheral bridge portion 29, the acting stress can be reduced as compared with the rotor 2C of Comparative Example 3.
  • F represents the force that the permanent magnet 4 acts on the second magnet holding surface 212C due to the centrifugal force.
  • Bending stress generated by the outer peripheral iron portion 24 protruding in the radial outer direction (positive direction) and causing a convex bending deformation in the radial inward acts on the outer peripheral bridge portion 22.
  • U is a "convex bend inward in the radial direction”. Bending stress generated by bending deformation that is convex outward in the radial direction acts on the quasi-outer peripheral bridge portion 29.
  • V is "a bending that is convex outward in the radial direction”.
  • the first magnet holding surface 211 and the second magnet holding surface 212 do not have to be in direct contact with the permanent magnet 4 as long as they have the effect of holding the permanent magnet 4 during rotation. Specifically, an adhesive and a resin for fixing the position may be sandwiched between the first magnet holding surface 211, the second magnet holding surface 212, and the permanent magnet 4.
  • the rotary electric machine of the third embodiment has a configuration in which the radial side of the permanent magnet embedded in the rotor is held on the radial outside of the rotor core against the centrifugal force during rotation of the rotor. is there. Therefore, the rotary electric machine of the third embodiment can reduce the stress at the bridge portion, suppress the torque decrease, and improve the durability of the rotor core. Further, it is possible to prevent a decrease in the reluctance torque and enhance the cooling effect of the permanent magnet.
  • Embodiment 4 In the rotary electric machine of the fourth embodiment, the slit is filled with a filler.
  • FIG. 25 is an enlarged plan view of one pole of the rotor.
  • the same or corresponding parts as those of the first embodiment are designated by the same reference numerals.
  • the rotary electric machine 400 is used.
  • the overall configuration of the rotor 2 of the fourth embodiment is the same as that of FIG. 2 of the first embodiment. That is, 24 magnet insertion holes 21 are arranged in the rotor core 3 at intervals in the circumferential direction, and permanent magnets 4 are embedded in each of the magnet insertion holes 21.
  • the magnet insertion hole 21 and the permanent magnet 4 form a set of two adjacent magnets in the circumferential direction, forming 12 V-shapes extending from the center side of the rotation axis toward the outside in the radial direction.
  • One magnetic pole is composed of two V-shaped magnet insertion holes 21 and two permanent magnets 4, and 12 magnetic poles are arranged side by side in the circumferential direction.
  • FIG. 25 is an enlarged plan view of the one pole of the rotor 2.
  • the thin-walled portion formed by being sandwiched between the magnet insertion hole 21 and the rotor outer peripheral surface 20 of the rotor core 3 is referred to as the outer peripheral bridge portion 22.
  • a thin-walled portion sandwiched between two magnet insertion holes 21 (21a, 21b) forming a V-shape, which is a central portion in the circumferential direction of the V-shape and is formed inside in the radial direction is referred to as a central bridge portion 23.
  • the triangular portion surrounded by the two magnet insertion holes 21 (21a, 21b) and the rotor outer peripheral surface 20 is referred to as the outer peripheral iron portion 24.
  • a slit 25 is formed in the outer peripheral iron portion 24.
  • the slit 25 includes an extension portion 251 extending radially inward from the rotor outer peripheral surface 20 and a gap portion 252.
  • the extending portion 251 is arranged so as to extend in the radial direction through the center of the magnetic pole.
  • the gap portion 252 is located at the tip of the slit 25 on the inner side in the radial direction, and has a width in the circumferential direction larger than the minimum width in the circumferential direction of the extension portion 251.
  • the structural feature of the rotary electric machine 400 of the fourth embodiment is that the slit 25 is filled with the filler 253.
  • the tensile stress in the circumferential direction acting on the outer peripheral bridge portion 22 can be reduced by the slit 25 as in the first embodiment. Therefore, also in the fourth embodiment, the stress generated in the rotor core 3 can be reduced.
  • the slit 25 is filled with the filler 253 to suppress the turbulence of air generated on the rotor surface. Therefore, it is possible to provide a rotary electric machine in which wind damage and noise are reduced while improving the durability of the rotor core 3. Further, since the slit 25 is composed of the stretched portion 251 and the gap portion 252, when the filler 253 tries to move in the radial direction, the slit 25 is caught in the gap portion 252 and the movement is suppressed. That is, it is possible to prevent the filler 253 from scattering outward in the radial direction due to centrifugal force.
  • the filled filler 253 is preferably a material having a rigidity of several tenths of that of the rotor core, and for example, a non-magnetic resin material is suitable.
  • the rotary electric machine of the fourth embodiment has a slit filled with a filler. Therefore, the rotary electric machine of the fourth embodiment can reduce the stress at the bridge portion, suppress the torque decrease, and improve the durability of the rotor core. Further, wind damage and noise generated by the slit can be suppressed.
  • the present application can be widely applied to rotary electric machines because it can reduce the stress of the bridge portion, suppress the torque decrease, and improve the durability of the rotor core.

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  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Permanent Field Magnets Of Synchronous Machinery (AREA)
  • Iron Core Of Rotating Electric Machines (AREA)

Abstract

La présente invention concerne une machine électrique rotative qui est pourvue d'un stator (1) et d'un rotor (2) pour tourner dans la circonférence interne du stator (1), dans lequel, dans un noyau de rotor (3), une pluralité d'aimants permanents (4) constituant des pôles magnétiques sont incorporés dans des trous d'insertion d'aimant (21) formés pénétrant à travers le noyau de rotor (3) dans la direction axiale. Chacun des pôles magnétiques est formé par au moins deux des aimants permanents (4). Au niveau de chacun des pôles magnétiques, une partie de fer circonférentielle externe (24) qui est entourée par les aimants permanents (4) et une partie circonférentielle externe de rotor (20) qui est pourvue d'une fente (25) formée par découpe de la surface circonférentielle externe de rotor (20) vers le côté radialement interne du rotor (2). L'extrémité avant sur le côté radialement interne de la fente (25) a un espace (252).
PCT/JP2019/029865 2019-07-30 2019-07-30 Machine électrique rotative WO2021019692A1 (fr)

Priority Applications (2)

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PCT/JP2019/029865 WO2021019692A1 (fr) 2019-07-30 2019-07-30 Machine électrique rotative
JP2020549723A JP7126557B2 (ja) 2019-07-30 2019-07-30 回転電機

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PCT/JP2019/029865 WO2021019692A1 (fr) 2019-07-30 2019-07-30 Machine électrique rotative

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Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2013153917A1 (fr) * 2012-04-10 2013-10-17 本田技研工業株式会社 Rotor pour machine électrique tournante
JP2014045630A (ja) * 2012-08-29 2014-03-13 Honda Motor Co Ltd 回転電機
JP2018137867A (ja) * 2017-02-21 2018-08-30 本田技研工業株式会社 回転電機のロータ、及び、回転電機の端面板
WO2019064801A1 (fr) * 2017-09-28 2019-04-04 三菱電機株式会社 Machine électrique tournante à aimant permanent

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP5073692B2 (ja) * 2009-01-28 2012-11-14 本田技研工業株式会社 回転電機
US10211689B2 (en) 2016-03-09 2019-02-19 Ford Global Technologies, Llc Electric machine rotor
WO2019008820A1 (fr) 2017-07-05 2019-01-10 三菱電機株式会社 Machine électrique tournante

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2013153917A1 (fr) * 2012-04-10 2013-10-17 本田技研工業株式会社 Rotor pour machine électrique tournante
JP2014045630A (ja) * 2012-08-29 2014-03-13 Honda Motor Co Ltd 回転電機
JP2018137867A (ja) * 2017-02-21 2018-08-30 本田技研工業株式会社 回転電機のロータ、及び、回転電機の端面板
WO2019064801A1 (fr) * 2017-09-28 2019-04-04 三菱電機株式会社 Machine électrique tournante à aimant permanent

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