JP2012244649A - Rotor and rotary electric machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an inexpensive rotor for a rotary electric machine that does not produce any eddy current, and to provide a rotary electric machine using the rotor.SOLUTION: A rotor 10 includes: a rotor core 14 that has a plurality of laminated magnetic steel sheets 12; a rotating shaft 16 that is mounted at center of the rotor core 14; a plurality of permanent magnets 18 that are embedded in the rotor core 14; and fixing members 20 that cover part of the respective magnets 18 while fixing the magnetic steel sheets 12. A rotary electric machine 50 includes the rotor 10, and a stator 52 that surrounds a lateral side of the rotor 10.

Description

  The present invention relates to a rotor of a rotating electric machine used for a compressor and the like, and a rotating electric machine using the rotor.

  Conventionally, an interior permanent magnet (IPM) rotating electric machine has been developed and disclosed (Patent Document 1, etc.). The rotating electrical machine includes a stator and a rotor. The stator is annular, and the rotor is disposed inside the stator. The rotor 100 includes a rotor core 14 in which disk-shaped electromagnetic steel plates 12 are laminated, a rotating shaft 16 attached to the center of the rotor core 14, a permanent magnet 18 embedded in a magnet hole 24 formed in the rotor core 14, End plates 102 are provided at both ends of the rotor core 14 (FIG. 11).

  The end plate 102 has substantially the same shape as that of the electromagnetic steel plate 12 and covers all the opening portions of the magnet holes 24. 7B to 7D of Patent Document 1 disclose an end plate that extends from one magnetic pole surface to another magnetic pole surface of a magnet. The end plate 102 prevents the magnet 18 from jumping out of the groove.

  However, magnetic flux leaking from one magnetic pole surface to the other magnetic pole surface passes through the end plate 102. Eddy current is generated by the magnetic flux, and eddy current loss occurs. Therefore, it is necessary to use a nonmagnetic material for the end plate 102, which is more expensive than a magnetic material. Moreover, as long as the end plate 102 is a metal, an eddy current is generated by the magnetic flux leaking to the end plate 102.

JP 2005-304177 A

  An object of the present invention is to provide an inexpensive rotary electric machine rotor that does not generate eddy currents and a rotary electric machine using the rotor.

  The rotor according to the present invention is made of a substantially cylindrical soft magnetic material, and has a plurality of magnet holes and a plurality of shaft holes that penetrate from one end to the other end, and the rotor core that rotates, and the rotor A magnet embedded in the magnet hole of the core, a head portion and a shaft portion, the shaft portion is disposed in the shaft portion hole of the rotor core, and the head portion is disposed at an end portion of the rotor core, and The electromagnetic steel plate is fixed, and the head includes a fixing member that covers a part of the magnet.

  The head covers less than half the thickness of the magnet. The fixing member is made of a magnetic material. Two magnets are covered with one head. The magnet hole and the shaft hole are integrated.

  In order to suppress the rotation blur of the rotor core, balance weights disposed at both ends of the rotor core are provided, and the fixing member is disposed at a position without the balance weight.

  A rotating electrical machine of the present invention includes the above-described rotor and a stator that is disposed so as to surround a side of the rotor.

  In the present invention, since the end plate is omitted, there is no magnetic flux passing through the conventional end plate, and eddy current loss due to the magnetic flux is not caused. Since the fixing member that prevents the magnet from jumping out of the magnet hole covers only a part of one magnetic pole of the magnet, the fixing member can be made of a magnetic material and is an inexpensive fixing member.

It is a figure which shows the structure of the rotor of this invention, (a) is a top view, (b) is an AA sectional view. It is an enlarged view of the location which covers a magnet with the head of a fixing member. It is the figure which covered a part of magnetic pole outside the magnet with the fixing member. It is the figure which covered two magnets with one fixing member. It is the figure which arranged the magnet in V shape, (a) is the figure which covered the two magnets with one fixing member, (b) is a figure which shows an electromagnetic steel plate. When magnets are arranged in a V shape, they are outside the magnet and cover the magnetic poles of the V-shaped valleys. It is the figure which covered the magnetic pole of the tip of a V character, when a magnet was arranged in V shape. It is a figure of the rotor which combined the structure of FIG. 6 and FIG. It is a figure which shows the structure at the time of providing a balance weight in a rotor. It is a figure which shows the structure of a rotary electric machine. It is a figure which shows the structure of the conventional rotor.

  The rotor and rotating electrical machine of the present invention will be described with reference to the drawings.

  1 includes a rotor core 14 in which a plurality of electromagnetic steel plates 12 are stacked, a rotating shaft 16 attached to the center of the rotor core 14, a plurality of permanent magnets 18 embedded in the rotor core 14, and an electromagnetic steel plate 12. A fixing member 20 that covers a part of the magnet 18 while being fixed is provided.

  The electromagnetic steel sheet 12 has a substantially disk shape. The electromagnetic steel sheet 12 is made of a soft magnetic material. The rotor core 14 is configured by laminating electromagnetic steel plates 12. Lamination is performed via an insulating layer (not shown) formed in advance on the surface of the electromagnetic steel sheet 12. A circular hole 22 for attaching the rotating shaft 16 is provided at the center of the rotor core 14 (electromagnetic steel plate 12), and the rotor core 14 has a substantially cylindrical shape when the electromagnetic steel plates 12 are laminated.

  The rotor core 14 has a magnet hole 24 and a shaft hole 26 that penetrate from one end to the other end of the rotor core 14. Further, a flux barrier 28 that is a hole penetrating from one end portion of the rotor core 14 to the other end portion is provided. The flux barrier 28 is connected to the end of the magnet hole 24, and faces the outer peripheral direction of the rotor core 14 from the end of the magnet hole 24. The flux barrier 28 prevents the magnetic flux of the magnet 18 from being short-circuited inside the rotor core 14 by making it difficult for the magnetic flux to pass through the electromagnetic steel sheet 12.

  The magnet 18 is embedded in the magnet hole 24. The plurality of magnets 18 are arranged so that the magnetic poles adjacent to each other in the circumferential direction of the rotor core 14 are different. N poles and S poles are alternately arranged in the circumferential direction of the rotor core 14. The number of magnets 18 arranged in the circumferential direction is an even number, and the magnets 18 are arranged at target positions around the rotation shaft 16.

  The fixing member 20 has a head portion 30 and a shaft portion 32. The head 30 has a flat surface. A shaft portion 32 is attached to the center of the plane, and the shaft portion 32 faces the vertical direction with respect to the plane. The fixing member 20 is a rivet, a caulking pin, a bolt and a nut, or the like. The shaft portion 32 is disposed in the shaft portion hole 26, and the head portion 30 is disposed at the end portion of the rotor core 14. A part of the head 30 contacts the end of the rotor core 14. When using a washer (washer) between the head 30 and the end of the rotor core 14, the washer is a part of the head 30 in the present invention.

  As shown in FIG. 2, a part of the head 30 covers a part of one magnetic pole of each magnet 18 by closing a part of the opening of the magnet hole 24. When the head 30 covers the north pole or the south pole in a certain magnet 18, the opposite magnetic pole is not covered. The portion covered by the head 30 is a half or less of the magnet 18 on the rotating shaft 16 side. Although a very small gap is formed between the magnet 18 and the magnet hole 24, the gap is covered beyond this gap. Since a part of the opening of the magnet hole 24 is blocked, the opening of the magnet hole 24 becomes narrower than the magnet 18 and the magnet 18 does not jump out.

  For example, as shown in FIG. 1, six magnets 18 are arranged in the circumferential direction to form a hexagon. One head 30 is configured to cover a part of one magnet 18. The number of fixing members 20 is also changed depending on the number of magnets 18. The shape of the head 30 shown in FIG. 1 is also circular, but may be polygonal.

  Conventionally, since magnetic flux leaking from the magnet 18 passes through the end plate, the generation of eddy currents has become a problem. However, since the present invention has no end plate, such eddy currents do not become a problem.

  The head 30 of the fixing member 20 does not extend from one magnetic pole of one magnet 18 to the other magnetic pole. In one magnet, magnetic flux leaking from the N pole to the S pole does not pass through the head 30. An eddy current is not generated in the head 30 by the magnetic flux. Therefore, the head 30 of the fixing member 20 can be made of a magnetic material such as iron. The fixing member 20 is cheaper than a nonmagnetic material.

  After the caulking pin or the bolt as the fixing member 20 is inserted into the shaft hole 26, the magnet 18 is inserted into the magnet hole 24 from the opposite side where the head 30 is disposed. The electromagnetic steel plate 12 is fixed by crushing the head 30 of the crimping pin or fastening it with a nut.

  In order to fix the electromagnetic steel plates 12 to each other, caulking 34 is also used. The caulking 34 is disposed on the opposite side of the fixing member 20 with respect to the magnet 18. Since the magnetic steel sheets 12 are fixed to each other by the fixing member 20 and the caulking 34 on the inner side and the outer side of the magnet 18 in the rotor core 14, a balance of the force for fixing can be obtained. The caulking 34 pushes a part of the electromagnetic steel sheet 12 into the die by a punch to form a caulking uneven part on the part of the electromagnetic steel sheet 12, and is fitted with the caulking uneven part adjacent to the rotation axis direction. It is held by friction.

  As described above, since there is no end plate provided in the conventional rotor, eddy current loss due to eddy current generated in the end plate does not occur. By omitting the end plate, the manufacturing becomes easy, and the yield can be improved and the price can be reduced. Since the fixing member 20 can be made of a magnetic material, it can be manufactured at a lower cost.

  In the first embodiment, the fixing member 20 is disposed on the rotating shaft 16 side of the rotor core 14 in the magnet 18, but the fixing member 20 is disposed on the outer peripheral side of the rotor core 14 in the magnet 18 as in the rotor 10b of FIG. It may be arranged. A part of the head 30 covers a part of the magnet 18 to prevent the magnet 18 from jumping out. The caulking 34 is provided inside the rotor core 14 with respect to the magnet 18. In addition, since the permanent magnet and the flux barrier 28 are exposed, the permanent magnet is cooled in applications where fluid flows in the axial direction of the rotating electrical machine, such as a compressor for an air conditioner as described later. Since it can be performed efficiently, it also has the effect of preventing demagnetization.

  In the first and second embodiments, one magnet 18 is covered with one head 30. However, like the rotor 10c in FIG. 4, two magnets 18 are covered with one head 30. Also good. When there are six magnets 18 as shown in FIG. 4, the magnets 18 are arranged in a hexagon. The head 30 is arranged at a hexagonal corner. The head 30 covers the ends of the two magnets 18 at the same time. When the number of the heads 30 in the first to third embodiments is summarized, it is equal to or half the number of the magnets 18.

  As in the rotor 10d of FIG. 5A, the magnets 18 may be arranged in the circumferential direction of the rotor core 14 while arranging the V shapes. The magnet 18 has magnetic poles 18 arranged alternately in the circumferential direction. In this case, in the electromagnetic steel sheet 12, the magnet hole 24 and the shaft hole 26 are integrated (FIG. 5B). By simultaneously covering a part of the two magnets 18 where the head 30 is a V-shaped valley, the two magnets 18 can be prevented from jumping out at the same time.

  In FIG. 5A, the magnetic pole on the rotating shaft 16 side is covered with the head 30 of the fixing member 20. However, like the rotor 10 e in FIG. The head 30 may be covered. Further, like the rotor 10f in FIG. 7, the magnetic poles of the adjacent V-shaped tip portions may be covered with the head 30 of one fixing member 20. Further, a configuration in which the rotors 10e and 10f in FIGS. 6 and 7 are combined may be used as in the rotor 10g in FIG. Both ends of the magnet 18 are respectively covered with the heads 30 of the fixing member 20. The rotor 10g in FIG. 8 is a combination of the rotors 10e and 10f in FIGS. 6 and 7, but may be a combination of the rotors 10d and 10f in FIGS.

  Like the rotor 10h of FIG. 9, the balance weight 40 may be arrange | positioned at the both ends of the rotor core 14 in order to suppress the rotation blur of the rotor core 14. FIG. The balance weight 40 blocks the magnet hole 24 and prevents the magnet 18 from jumping out. Therefore, a part of the head 30 of the fixing member 20 covers a part of the magnet 18 only in a place where the balance weight 40 is not present. The balance weight 40 is provided with a shaft hole 26 ′, and the shaft portion 32 is simultaneously passed through the shaft hole 26 of the rotor core 14 and the shaft hole 26 ′ of the balance weight 40. The rotor core 14 and the balance weight 40 are simultaneously fixed by the fixing member 20.

  The rotor 10 described in each of the above embodiments is used for a rotating electrical machine. The rotating electrical machine 50 includes the rotor 10 and a stator 52 that surrounds the side of the rotor 10 (FIG. 10). Although FIG. 10 shows the rotor 10 of FIG. 1, the rotor 10b of FIG.

  The stator 52 includes an annular back yoke 54, a plurality of teeth 56 extending from the back yoke 54 toward the annular center, a slot 58 formed between adjacent teeth 56, a coil 60 disposed in the slot 58, a back A slot cell 62 that insulates the coil 60 from the yoke 54 and the tooth 56 is provided.

  The back yoke 54 and the teeth 56 are integrated, and form a stator core 64 by them. The stator core 64 is formed by laminating a plurality of electromagnetic steel plates made of a soft magnetic material via an insulating layer. The teeth 56 are arranged at equal intervals. The slot 58 is a space between the teeth 56, and the coil 60 is disposed in this space. The slot cell 62 is an insulating film such as a PET (polyethylene terephthalate) film. The slot cell 62 is disposed between the stator core 64 and the coil 60 to ensure insulation between the stator core 64 and the coil 60.

  The outer periphery of the stator core 64 is fixed to a case 66 or the like and applied to various rotating electrical machines 50. Examples of the fixing method to the case 66 include shrink fitting and welding. The rotating electrical machine 50 can be applied to various motors and generators including motors used in compressors of air conditioners.

  In addition, the present invention can be carried out in a mode in which various improvements, modifications, and changes are added based on the knowledge of those skilled in the art without departing from the gist thereof. Each embodiment is not independent or exclusive, and may be implemented in combination as appropriate. For example, an end plate may be provided at one end of the rotor core, and the present invention may be applied to the other end. In addition, the rotor core has been described as an example in which magnetic steel sheets that are excellent in that the saturation magnetic flux density is high and the hysteresis loss is small are laminated, but a soft magnetic material formed by other methods, such as a dust core, etc. It may be.

10, 10b, 10c, 10d, 10e, 10f, 10g, 10h: rotor 12: electromagnetic steel plate 14: rotor core 16: rotating shaft 18: magnet 20: fixing member 22: hole 24 for attaching the rotating shaft 24: for magnet Hole 26: Shaft hole 28: Flux barrier 30: Head part 32: Shaft part 34: Caulking 40: Balance weight 50: Rotary electric machine 52: Stator 54: Back yoke 56: Teeth 58: Slot 60: Coil 62: Slot Cell 64: Stator core 66: Case

Claims (7)

A rotor core made of a substantially cylindrical soft magnetic material, having a plurality of holes for magnets and a plurality of holes for shafts penetrating from one end to the other end, and rotating,
A magnet embedded in a magnet hole of the rotor core;
A shaft portion is disposed in the shaft portion hole of the rotor core, the head portion is disposed at an end portion of the rotor core to fix a plurality of electromagnetic steel plates, and the head portion is a magnet. A fixing member covering the part;
With a rotor. The rotor according to claim 1, wherein the head covers half or less of the thickness of the magnet. The rotor according to claim 1, wherein the fixing member is made of a magnetic material. The rotor according to claim 1, wherein the two magnets are covered with one head. The rotor according to claim 4, wherein the magnet hole and the shaft hole are integrated. The rotor according to any one of claims 1 to 5, further comprising a balance weight that suppresses rotation blur of the rotor core at both ends of the rotor core, and the fixing member is disposed at a position without the balance weight. A rotor according to any of claims 1 to 6;
A stator arranged so as to surround a side of the rotor;
Rotating electric machine with

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