JP6268580B2 - Rotor for electric motor - Google Patents

Description

The present invention relates to a rotor core having a plurality of insertion holes equally spaced in the circumferential direction; an outer magnetic pole surface facing the radially outer side of the rotor core; and the outer magnetic pole surface facing the radially inner side of the rotor core The outer magnetic pole surface parallel to the rotor core and the outer magnetic pole surface along the circumferential direction of the rotor core and a pair of side surfaces connecting both ends of the inner magnetic pole surface are formed in a rectangular cross section a permanent magnet is inserted to each of a plurality of the insertion holes together; provided with an inner wall of the insertion hole, a part of the pair of the side nearer of said outer pole face, said outer pole of said side surfaces of a pair A pair of hollow portion forming walls that form a pair of hollow portions that face a portion near the surface and a pair of hollow portions that respectively face the pair of corners between the outer magnetic pole surface and the pair of side surfaces ; Remaining pole face For an electric motor configured as a magnet-embedded type, comprising an outer support wall to support, an inner support wall that supports all of the inner magnetic pole surface, and a pair of side support walls that support the rest of the pair of side surfaces Regarding the rotor.

  In order to reduce the cogging torque of an electric motor whose rotor is of an embedded magnet type, a hollow part that faces the corner on the outer magnetic pole surface side of a permanent magnet having a rectangular cross section is formed in the rotor core. This is known from Patent Document 1.

JP 2013-198215 A

  By the way, the insertion hole provided in the rotor core is formed larger than the dimension of the permanent magnet in order to enable the insertion of the permanent magnet. In the one disclosed in Patent Document 1, the permanent magnet and the insertion hole are provided. Among these, a clearance is generated between the outer side of the permanent magnet and the inner side corresponding to the inner magnetic pole surface, and the magnet is attracted to a portion with a lot of iron (a portion where the magnetic flux easily passes). The position where the surface comes into contact with the rotor core is not only a possibility of causing a gap in the position where the resistance on the magnetic path is likely to increase, leading to a decrease in torque, but also the position of the permanent magnet is not fixed and it is difficult to assemble Yes.

  The present invention has been made in view of such circumstances, so that the permanent magnet can be positioned on the side where the outer magnetic pole surface is in contact with the rotor core, facilitating the production, and also improving the performance of the electric motor. An object of the present invention is to provide a motor rotor.

In order to achieve the above object, the present invention provides a rotor core having insertion holes extending in the axial direction and provided at a plurality of positions spaced at equal intervals in the circumferential direction, and an outer magnetic pole surface facing the radially outer side of the rotor core. An inner magnetic pole surface facing the radially inner side of the rotor core and parallel to the outer magnetic pole surface, and a pair of side surfaces connecting both ends of the outer magnetic pole surface and the inner magnetic pole surface along the circumferential direction of the rotor core. And a permanent magnet inserted into each of the plurality of insertion holes, the inner wall of the insertion hole being a pair of the side surfaces of the outer magnetic pole surface. some of the deviation, and the portion of the outer pole face close, and the permanent magnet with a pair of hollow portions for exposing each pair of corners of between the outer magnetic pole surface and a pair of said side surfaces of said side surfaces of a pair Between A pair of hollow portion forming walls to be formed, an outer support wall that supports the remaining portion of the outer magnetic pole surface, an inner support wall that supports all of the inner magnetic pole surface, and a pair of side surfaces that support the remaining portion of the pair of side surfaces In the motor rotor configured to be embedded in a magnet so as to include a support wall, the inner pole face and the remaining part of the pair of side surfaces are interposed between the inner support wall and the pair of side support walls. A single spacer member is inserted into the insertion hole so as to press the outer magnetic pole face of the permanent magnet against the outer support wall side, and a pair of spacer members is connected to the end of the spacer member from the side support wall. the hollow portion pair of exposed portion slightly extending side is formed, and a pair of said exposed portion of said spacer member and a pair of the corner of the permanent magnet that is fixed to the rotor core, said permanent A first feature in that the stone (15) and adhesive for securing the spacer member (28) at once the rotor core (14) (29) is filled to the pair of the hollow portion (20) To do.

  According to the present invention, in addition to the configuration of the first feature, the insulating member interposed between the stator core and the stator coil of the stator surrounding the rotor core, and the spacer member are both made of insulating paper made of aramid polymer. This is a second feature.

According to the first feature of the present invention, the permanent magnet is configured such that the outer magnetic pole surface of the permanent magnet is pressed against the outer support wall side of the insertion hole facing the outer magnetic pole surface by inserting the spacer member into the insertion hole. The adhesive that fixes the pair of corners of the permanent magnet and the pair of exposed portions of the spacer member to the rotor core is positioned on the outer side along the radial direction of the rotor core. By filling the portion , the permanent magnet and the spacer member are fixed to the rotor core all at once, so that the manufacture of the rotor is facilitated, the position of the permanent magnet is stabilized, and the performance of the electric motor is improved.

  Further, according to the second feature of the present invention, the spacer member and the insulating member interposed between the stator core and the stator coil of the stator are made of the same material, so that the cost can be reduced.

It is a cross-sectional view of an electric motor. FIG. 2 is an enlarged view of a portion indicated by an arrow 2 in FIG. 1. FIG. 3 is an enlarged view of a portion indicated by an arrow 3 in FIG. 2.

  Hereinafter, embodiments of the present invention will be described with reference to FIGS. 1 to 3 attached herewith. First, in FIG. 1, the electric motor includes a stator 6 mounted inside a cylindrical motor case 5, A rotating shaft 7 is coaxially and rotatably supported on the motor case 5, and a rotor 8 is fixed to the rotating shaft 7 so as to be surrounded by the stator 6.

  Referring also to FIG. 2, the stator 6 is radially inward from a cylindrical yoke 9a along the inner periphery of the motor case 5 and from a plurality of locations spaced equally in the circumferential direction of the inner periphery of the yoke 9a. The stator core 9 integrally having the stator teeth 9b protruding in the direction and the stator coils 10 wound around the stator teeth 9b are provided to the rotor 8 by selective energization / excitation of the plurality of stator coils 10. A rotational force can be applied. An insulating member 11 is interposed between the stator core 9 and the stator coil 10, and this insulating member 11 is made of insulating paper made of, for example, an aramid (fully aromatic polyamide) polymer known as Nomex (registered trademark). .

  The rotor 8 includes a central hole 12 through which the rotating shaft 7 is inserted and a plurality of, for example, six insertion holes provided around the central hole 12 provided at a plurality of positions spaced at equal intervals in the circumferential direction. And a plurality of, for example, six permanent magnets 15 fixed to the rotor core 14 in a state of being inserted into the insertion holes 13 respectively.

  The permanent magnet 15 is made of, for example, a neodymium-based sintered magnet. The outer magnetic pole surface 16 faces the radially outer side of the rotor core 14 and the outer magnetic pole surface faces the radially inner side of the rotor core 14. 16 and an inner magnetic pole surface 17 parallel to 16 and a pair of side surfaces 18 and 18 connecting both ends of the outer magnetic pole surface 16 and the inner magnetic pole surface 17 along the circumferential direction of the rotor core 14. The cross section is formed in a rectangular shape.

  Each permanent magnet 15 is magnetized such that the magnetic poles of the outer magnetic pole surface 16 and the inner magnetic pole surface 17 are different from each other, and the outer magnetic pole surface 16 of the permanent magnet 15 adjacent in the circumferential direction of the rotor core 14. A plurality of permanent magnets 15 are arranged in the circumferential direction of the rotor core 14 such that the magnetic poles of the inner magnetic pole surfaces 17 are opposite to each other.

Referring also to FIG. 3, the inner wall of the insertion hole 13 is a part of the permanent magnet 15 near the side surface 18, 18 of the outer magnetic pole surface 16, and the side surface 18 , 18 near the outer magnetic pole surface 16. And a pair of hollow portion forming walls 21 that form hollow portions 20, 20 that face corner portions 25 , 25 between the outer magnetic pole surface 16 and the side surfaces 18, 18, with the permanent magnet 15. 21, a flat outer support wall 22 that supports the remaining portion of the outer magnetic pole surface 16, a flat inner support wall 23 that supports all of the inner magnetic pole surface 17, and a pair that supports the remaining portions of the side surfaces 18 and 18. Side support walls 24, 24.

  The hollow portion forming wall 21 extends in a direction away from the side surface of the permanent magnet 15 while extending an extension line toward the inner support wall 23 at a shallow angle so as to intersect the inner support wall 23. A first inclined side portion 21a that rises slightly inclined from the side support wall 24, a second inclined side portion 21b that continues to the outer end of the first inclined side portion 21a at a steeper angle than the first inclined side portion 21a, A circular arc side portion 21c extending at one end to the outer end of the second inclined side portion 21b and extending along the outer peripheral surface of the rotor core 14; a folded side portion 21d having one end connected to the other end of the circular arc side portion 21c; A third inclined side portion 21e extending obliquely from the other end of the side portion 21d toward the outer magnetic pole face 16 of the permanent magnet 15, and a curved side portion 21f connecting the third inclined side portion 21e and the outer support wall 22 Have

  The hollow portion 20 formed between the hollow portion forming wall 21 and the permanent magnet 15 is a portion other than the portion corresponding to the side support wall 24 in the side surface 18 of the permanent magnet 15, that is, the side surface 18. A substantially trapezoidal side-surface-side hollow portion 20a that faces a portion near the outer magnetic pole surface 16 and a substantially U-shape that faces a portion near the side surface 18 of the outer magnetic pole surface 16 in the permanent magnet 15. The side-side hollow portion 20a and the outer-side hollow portion 20b are divided into outer peripheral-side hollow portions 20b, and the narrow-side portions 20c corresponding to the corner portions 25 between the outer magnetic pole surface 16 and the side surfaces 18 in the permanent magnet 15 are defined. It will be communicated via.

  A part of the outer peripheral side hollow part 20b is a part of the hollow part forming wall 21 that constitutes a part of the folded side part 21d, the third inclined side part 21e, and the curved side part 21f. The wall 26 formed is separated from the outer magnetic pole surface 16 of the permanent magnet 15, and the gap in the magnetic pole direction of the permanent magnet 15 (direction orthogonal to the outer magnetic pole surface 16) in the outer peripheral hollow portion 20 b is the side surface. From the position farthest away from the side hollow portion 20a toward the corner portion 25 side of the permanent magnet 15, the curved side portion 21f of the hollow portion forming wall 21 and the connecting portion of the outer support wall 22 are provided. It passes through the straight line L perpendicular to the outer magnetic pole face 16 and becomes the maximum, and gradually decreases toward the corner 25, and the portion corresponding to the corner 25 becomes the minimum gap.

  According to such a hollow portion 20, the magnetic flux density between the outer peripheral surface of the rotor core 14 and the stator teeth 9 b of the stator 6 extends from the central portion of the permanent magnet 15 along the circumferential direction of the rotor core 14 to the corner portion 25 of the permanent magnet 15. Since it gradually becomes lower and then becomes higher, the portion of the rotor core 14 having a high magnetic flux density in the circumferential direction can be dispersed, and the degree of change in the magnetic flux density in the circumferential direction can be reduced gradually. Torque and torque ripple can be effectively and efficiently suppressed. Further, since the gap after the enlargement gradually decreases toward the corner 25, the degree of change in the magnetic flux density that gradually increases toward the corner 25 is gradually reduced so that cogging torque and torque ripple are generated. Further suppression can be achieved. In addition, a part of the outer peripheral side hollow portion 20 b of the hollow portion 20 is separated from the outer magnetic pole surface 16 of the permanent magnet 15 by the wall portion 26 formed in the rotor core 14. The magnetic flux from the magnetic pole surface 16 flows to the outer periphery of the rotor core 14 and the stator teeth 9b side via the wall portion 26, and the magnetic flux passing through the wall portion 26 can effectively contribute to the magnet torque. .

By the way, according to the present invention, the remaining part of the permanent magnet 15 excluding the inner magnetic pole face 17 and the pair of side faces 18, 18 excluding a part facing the hollow part 20, the inner support wall 23 and the pair of rotor cores 14. The spacer member 28 interposed between the side support walls 24 and 24 is inserted into the insertion hole 13 so as to press the outer magnetic pole surface 16 of the permanent magnet 15 against the outer support wall 22 side. The hollow portion 20 is filled with an adhesive 29 for fixing the permanent magnet 15 and the spacer member 28 to the rotor core 14. Incidentally end of the spacer member 28 has a exposed portion from the front SL side support wall 24 extends slightly into the hollow portion 20 (28a).

  As the adhesive 29, one having room temperature curability is appropriately used. For example, a silicone liquid gasket such as Three Bond Co., Ltd. 1200 series is used.

  The spacer member 28 is made of a common material with the insulating member 11 interposed between the stator core 9 and the stator coil 10 of the stator 6, and is made of, for example, insulating paper made of aramid polymer.

Next, the operation of this embodiment will be described. The inner magnetic pole surface 17 of the permanent magnet 15 and the remaining portion of the pair of side surfaces 18, 18 except for the portion facing the hollow portion 20, the inner support wall 23 of the rotor core 14, and the pair A spacer member 28 interposed between the side support walls 24 and 24 of the permanent magnet 15 is inserted into the insertion hole 13 so as to press the outer magnetic pole surface 16 of the permanent magnet 15 against the outer support wall 22 side of the rotor core 14. Therefore, by inserting the spacer member 28 into the insertion hole 13, the outer magnetic pole surface 16 of the permanent magnet 15 is pressed against the outer support wall 22 side of the insertion hole 13 facing the outer magnetic pole surface 16. Is positioned in contact with the rotor core 14 on the outer side along the radial direction of the rotor core 14, and the permanent magnet 15 and the spacer are positioned. By adhesive 29 for fixing the member 28 to the rotor core 14 is filled in the hollow portion 20, the exposed portion to the hollow portion 20 of the angle portion 25 and the spacer member 28 of the permanent magnet 15 (28a ) Is fixed to the rotor core 14 at once and firmly, and the permanent magnet 15 and the spacer member 28 are positioned and bonded in advance before being inserted into the insertion hole 13 at the time of manufacture. A small assembly process is not required, the manufacture of the rotor 8 is facilitated, the position of the permanent magnet 15 is stabilized, and the performance of the electric motor is improved.

  Further, since both the insulating member 11 interposed between the stator core 9 and the stator coil 10 of the stator 6 and the spacer member 28 are made of insulating paper made of aramid polymer, for example, the insulating member 11 and the insulating member 11 The spacer member 28 can be cut out collectively to reduce the cost.

  Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various design changes can be made without departing from the present invention described in the claims. Is possible.

6 ... stator 8 ... rotor 9 ... stator core 10 ... stator coil 11 ... insulating member 13 ... insertion hole 14 ... rotor core 15 ... permanent magnet 16 ... outer magnetic pole Surface 17 ... Inner magnetic pole surface 18 ... Side 20 ... Hollow part 21 ... Hollow part forming wall 22 ... Outer support wall 23 ... Inner support wall 24 ... Side support wall
25 ... Corner 28 ... Spacer member
28a..Exposed part 29 ... Adhesive

Claims (2)

A rotor core (14) having a plurality of insertion holes (13) equally spaced in the circumferential direction; an outer magnetic pole face (16) facing radially outward of the rotor core (14); a radius of the rotor core (14) The inner magnetic pole surface (17) facing the inner side in the direction and parallel to the outer magnetic pole surface (16), and the outer magnetic pole surface (16) and the inner magnetic pole surface (17) along the circumferential direction of the rotor core (14). A permanent magnet (15) which is formed in a rectangular cross-section so that the outer shape is formed by a pair of side surfaces (18) connecting both ends of each of the two and inserted into the plurality of insertion holes (13); With
The inner wall of the insertion hole (13), said outer pole face (16) a pair of said side surfaces (18) near a part of, the outer pole face (16) toward one of a pair the side of (18) A part and a pair of hollow portions (20) for facing a pair of corners (25) between the outer magnetic pole surface (16) and the pair of side surfaces (18) , respectively, are disposed between the permanent magnet (15). A pair of hollow portion forming walls (21) to be formed, an outer support wall (22) for supporting the remainder of the outer magnetic pole surface (16), and an inner support wall (23 for supporting all of the inner magnetic pole surface (17). ) And a pair of side surface support walls (24) that support the rest of the pair of side surfaces (18).
A single spacer member (28) interposed between the inner magnetic pole surface (17) and the remaining portion of the pair of side surfaces (18) and the inner support wall (23) and the pair of side surface support walls (24). ) Is inserted into the insertion hole (13) so as to press the outer magnetic pole surface (16) of the permanent magnet (15) against the outer support wall (22), and is inserted into the end of the spacer member 28. Is formed with a pair of exposed portions (28a) slightly extending from the side support walls 24 toward the pair of hollow portions (20) ,
By fixing the pair of corners (25) of the permanent magnet (15) and the pair of exposed portions (28a) of the spacer member (28) to the rotor core (14), the permanent magnet (15) And a pair of the hollow portions (20) filled with an adhesive (29) for fixing the spacer member (28) to the rotor core (14) at a stroke , respectively .   The insulating member (11) interposed between the stator core (9) and the stator coil (10) of the stator (6) surrounding the rotor core (14) and the spacer member (28) are both made of aramid polymer. The rotor for an electric motor according to claim 1, wherein the rotor is made of insulating paper.

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