JP2015104267A - Rotor and permanent magnet motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rotor and a permanent magnet motor capable of suppressing manufacturing cost while preventing demagnetization of a permanent magnet.SOLUTION: A rotor 1 includes a shaft 2, a columnar buffer member 4 integrally formed on a periphery of an inner peripheral side iron core firmly fixed to the shaft 2 and a cylindrical permanent magnet part covering the outer peripheral side of the buffer member 4. The permanent magnet part includes an upper side permanent magnet section 53 and a lower side permanent magnet section 54 which are divided in an axial direction of the shaft 2, the upper side permanent magnet section 53 has an outer peripheral side first upper iron core 532 (upper side abutting portion 532') abutted on an upper end face 42 of the buffer member 4 and the lower side permanent magnet section 54 has an outer peripheral side first lower iron core 542 (lower side abutting portion 542') abutting on a lower end face 43 of the buffer member 4. A permanent magnet motor includes the rotor 1 and a stator arranged so as to be opposed to the outer peripheral side of the rotor 1 through a predetermined interval.

Description

  The present invention relates to a rotor and a permanent magnet electric motor using the rotor.

  A conventional permanent magnet motor has an inner rotor type motor in which a rotor having a permanent magnet is rotatably arranged inside a stator that generates a rotating magnetic field. For example, a blower fan mounted on an air conditioner is provided. Used as a brushless DC motor for rotational driving.

  Such a rotor of a permanent magnet electric motor vibrates the permanent magnet by, for example, filling a cushioning member such as rubber between the rotor core fixed to the shaft and the permanent magnet disposed on the outer peripheral side of the rotor core. It is made not to transmit to a ventilation fan (for example, refer patent document 1).

  However, since the vibration isolation structure of the rotor according to Patent Document 1 is integrally formed with a buffer member from the shaft to the permanent magnet, there is no step of fitting the buffer member, and the number of steps for assembling the rotor can be reduced. There is a possibility that the permanent magnet may be demagnetized by heat at the time of integral molding of the members, and there is a problem that the mold for injection molding for integral molding becomes large. Furthermore, when the axial length of the permanent magnet motor is changed, there is a problem that a mold for injection molding must be manufactured each time.

JP 2001-268831 A

  An object of this invention is to provide the rotor and permanent magnet motor which can suppress manufacturing cost, preventing the demagnetization of a permanent magnet in view of the said problem.

  In order to solve the above-described problems, a rotor according to the present invention includes a shaft, a columnar buffer member integrally formed around the inner peripheral iron core fixed to the shaft, and a cylindrical permanent member that covers the outer peripheral side of the buffer member. The permanent magnet part includes an upper permanent magnet part and a lower permanent magnet part that are divided in the axial direction of the shaft, and the upper permanent magnet part contacts the upper end surface of the buffer member. It has an upper contact part, and the lower permanent magnet part has a lower contact part which contacts the lower end surface of a buffer member. The permanent magnet motor according to the present invention includes the rotor and a stator arranged to face the outer peripheral side of the rotor at a predetermined interval.

  In the rotor of the present invention, the upper permanent magnet portion includes an outer peripheral side upper iron core and a plurality of first permanent magnets arranged in the circumferential direction of the outer peripheral side upper iron core, and the lower permanent magnet portion is an outer peripheral side lower iron core. And a plurality of second permanent magnets arranged in the circumferential direction of the outer peripheral side lower iron core.

  In the rotor of the present invention, both end surfaces in the axial direction of the permanent magnet portion are pressed by an annular end plate.

  According to the rotor and the permanent magnet motor of the present invention, since the shock-absorbing member is integrally formed with the shaft in advance before the permanent magnet portion is attached to the rotor, the permanent magnet portion is exposed to heat during the integral molding. There is no. In addition, a smaller injection mold can be used as compared with the case where the buffer member is integrally formed between the shaft and the permanent magnet portion.

  According to the rotor of the present invention, the upper permanent magnet part includes a plurality of first permanent magnets arranged in the circumferential direction of the outer peripheral side upper iron core, and the lower permanent magnet part is arranged in the circumferential direction of the outer peripheral side lower iron core. In addition, since the plurality of second permanent magnets are provided, the upper permanent magnet portion and the lower permanent magnet portion can have the same shape so that the members can be shared.

  According to the rotor of the present invention, since both end faces of the permanent magnet portion are pressed by the end plates, the permanent magnet portion can be fixed to the shaft in a state where the permanent magnet portion is in contact with the buffer member.

It is an external appearance perspective view which shows the rotor by this invention. It is a disassembled perspective view shown in FIG. 1 of the rotor by this invention. It is sectional drawing shown in FIG. 1 of the rotor by this invention, (a) is AA sectional drawing, (b) is BB sectional drawing. It is sectional drawing which shows the permanent magnet electric motor using the rotor by this invention. It is a top view which shows the permanent magnet electric motor using the rotor by this invention. It is an external appearance perspective view which shows the rotor by other embodiment. It is an external appearance perspective view except the permanent magnet part of the rotor by other embodiment. It is CC sectional drawing shown in FIG. 6 of the rotor by other embodiment. FIG. 9 is an exploded cross-sectional view of a rotor according to another embodiment shown in FIG. 8.

  Embodiments of the present invention will be described below in detail with reference to the accompanying drawings. 1 to 9 are views for explaining a rotor and a permanent magnet motor using the rotor in the present embodiment. This permanent magnet motor is an inner rotor type motor in which a rotor having a permanent magnet is rotatably arranged in a stator that generates a rotating magnetic field. For example, in order to rotationally drive a blower fan mounted on an air conditioner Used as a brushless DC motor.

  As shown in FIGS. 1 to 3, the rotor 1 includes a shaft 2, a cylindrical inner peripheral iron core 3 fixed to the shaft 2, and a rubber or elastomer integrally formed around the inner peripheral iron core 3. A columnar cushioning member 4 made of a material such as a cylinder, a cylindrical permanent magnet portion 5 disposed on the outer peripheral side of the cushioning member 4, and the permanent magnet portion 5 facing the cushioning member 4 from both axial end surfaces of the shaft 2. And an end plate 6 to be pressed down.

  The permanent magnet portion 5 includes an upper permanent magnet portion 53 and a lower permanent magnet portion 54 that are divided in the axial direction. The upper permanent magnet portion 53 includes an outer peripheral side upper iron core 531 and a first permanent magnet 534. The outer peripheral side upper iron core 531 includes a disk-shaped outer peripheral side first upper iron core 532 and a cylindrical outer peripheral side second upper iron core 533, and the outer peripheral side upper iron core 531 is formed of the outer peripheral side first upper iron core 532. The outer peripheral second upper iron core 533 is fixed to the lower surface 532a. The lower permanent magnet portion 54 includes an outer peripheral lower iron core 541 and a second permanent magnet 544. The outer peripheral lower iron core 541 includes a disk-shaped outer peripheral first lower iron core 542 and a cylindrical outer peripheral second lower iron core 543, and the outer peripheral lower iron core 541 is the outer peripheral first lower iron core 542. The outer peripheral side second lower iron core 543 is fixed to the upper surface 542a.

  The end plate 6 is formed in an annular shape, pressing the upper end surface 51 of the outer peripheral side first upper iron core 532 and the lower end surface 52 of the outer peripheral side first lower iron core 542 from the axial direction of the shaft 2, The shaft 2 is crimped and fixed by being deformed. Further, although not shown, a vibration isolating member is disposed between the end plate 6 and the outer peripheral side first upper iron core 532 and between the end plate 6 and the outer peripheral side first lower iron core 542, and the permanent magnet portion 5. Vibration is not transmitted to the shaft 2. Instead of the end plate 6, for example, a retaining ring such as an E type or a C type may be used, and the retaining ring may be fitted into a groove formed in the shaft 2.

  The inner peripheral side iron core 3 includes a plurality of first convex portions 31 that extend in the axial direction of the shaft 2 and protrude in the radial direction on the outer peripheral side thereof. The buffer member 4 is formed in a columnar shape so as to cover the inner peripheral side iron core 3, and includes a plurality of second convex portions 41 protruding in the radial direction on the outer peripheral side thereof. The first convex portion 31 provided on the inner peripheral side iron core 3 and the second convex portion 41 provided on the buffer member 4 are such that the permanent magnet portion 5 does not rotate idly with respect to the shaft 2 and the permanent magnet portion 5 rotates. Torque is reliably transmitted to the shaft 2.

  The upper permanent magnet portion 53 has an upper contact portion 532 ′ that contacts the upper end surface 42 of the buffer member 4, and the upper contact portion 532 ′ includes an outer peripheral side first upper iron core 532 in this embodiment. The lower permanent magnet portion 54 has a lower contact portion 542 ′ that contacts the lower end surface 43 of the buffer member 4, and this lower contact portion 542 ′ is the outer peripheral first lower iron core 542 in this embodiment. It is made up of.

  A plurality of outer peripheral side second upper iron cores 533 of the upper permanent magnet portion 53 are fitted on the inner peripheral side of the second convex portion 41 of the buffer member 4 extending in the axial direction of the shaft 2 and recessed in the radial direction. The recess 533a is provided. The lower end surface 533 b of the outer peripheral side second upper iron core 533 is in contact with the outer peripheral side lower iron core 541. Further, the upper permanent magnet portion 53 includes a plurality of arc-shaped first permanent magnets 534 that are arranged in the circumferential direction on the outer peripheral side of the outer peripheral upper iron core 531, for example, by sintering magnet powder. The first permanent magnet 534 is longer in the axial direction than the outer peripheral side upper iron core 531 and protrudes downward from the outer peripheral side upper iron core 531 to the outer peripheral surface of the outer peripheral side upper iron core 531 in the circumferential direction of the first permanent magnet 534. They are arranged at intervals corresponding to the width.

  The outer peripheral side second lower iron core 543 of the lower permanent magnet portion 54 is fitted on the inner peripheral side of the second convex portion 41 of the buffer member 4 that extends in the axial direction of the shaft 2 and is recessed in the radial direction. A plurality of recesses 543a are provided. The upper end surface 543 b of the outer peripheral side second lower iron core 543 is in contact with the outer peripheral side upper iron core 531. Similarly to the first permanent magnet 534 arranged in the circumferential direction on the outer peripheral side of the outer peripheral lower iron core 541, the lower permanent magnet portion 54 has a plurality of arc-shaped second permanent magnets sintered with magnet powder. 544. The second permanent magnet 544 is longer in the axial direction than the outer peripheral lower iron core 541 and protrudes upward from the outer lower iron core 541 in the circumferential direction of the second permanent magnet 544 on the outer peripheral surface of the outer peripheral lower iron core 541. They are arranged at intervals corresponding to the width.

  When the upper permanent magnet portion 53 and the lower permanent magnet portion 54 are combined, the first permanent magnet 534 and the second permanent magnet 544 are alternately arranged in the circumferential direction. Since the upper permanent magnet portion 53 and the lower permanent magnet portion 54 have the same shape, a common member can be used for the upper permanent magnet portion 53 and the lower permanent magnet portion 54. The first permanent magnet 534 and the second permanent magnet 544 are magnetized after the rotor 1 is assembled.

  The procedure for assembling the rotor 1 configured as shown in FIG. 1 will be described with reference to FIGS. As shown in FIG. 2, the lower permanent magnet portion 54 is fitted from the lower end surface 43 side of the buffer member 4 integrally formed with the inner peripheral iron core 3 as indicated by an arrow a. At this time, the concave portion 543a of the outer peripheral side second lower iron core 543 is fitted into the second convex portion 41 of the buffer member 4, and the upper surface 542a of the outer peripheral side first lower iron core 542 is placed under the buffer member 4 as shown in FIG. It abuts on the end face 43.

  Next, the upper permanent magnet portion 53 is fitted from the upper end face 42 side of the shock-absorbing member 4 integrally formed with the inner peripheral iron core 3 as indicated by an arrow b. At this time, the concave portion 533a of the outer peripheral side second upper iron core 533 is fitted to the second convex portion 41 of the buffer member 4, and the lower surface 532a of the outer peripheral side first upper iron core 532 is placed on the buffer member 4 as shown in FIG. It abuts on the end face 42. As a result, the outer peripheral second lower iron core 543 of the lower permanent magnet portion 54 and the outer peripheral second upper iron core 533 of the upper permanent magnet portion 53 abut.

  Thereafter, the second permanent magnet 544 of the lower permanent magnet portion 54 and the outer peripheral side upper iron core 531 of the upper permanent magnet portion 53 are bonded to the second permanent magnet 544 or the outer peripheral side upper iron core 531 with an adhesive applied in advance. Similarly, the first permanent magnet 534 of the upper permanent magnet portion 53 and the outer peripheral lower iron core 541 of the lower permanent magnet portion 54 are bonded to the first permanent magnet 534 or the outer peripheral lower iron core 541 with an adhesive applied in advance. The second permanent magnet 544 and the first permanent magnet 534 are fixed to the outer peripheral side lower iron core 541 and the outer peripheral side upper iron core 531 in advance, respectively, but the present invention is not limited to this. For example, the outer peripheral side upper iron core 531 After fixing the outer peripheral side lower iron core 541 to the shaft 2, the first permanent magnet 534 and the second permanent magnet 544 may be bonded together. Further, the outer peripheral iron core is not limited to the upper and lower parts, and may be divided into three or more in the axial direction.

Next, the end plate 6 is inserted into the shaft 2, the end plate 6 is pressed against the outer peripheral side first lower iron core 542 and the outer peripheral side first upper iron core 532, and the portion near the shaft 2 of the end plate 6 is crimped and deformed. Then, the end plate 6 is pressed against the shaft 2.
Thereby, the upper surface 542a of the outer peripheral side first lower iron core 542 is pressed against the lower end surface 43 of the buffer member 4, and the lower surface 532a of the outer peripheral side first upper iron core 532 is pressed against the upper end surface 42 of the buffer member 4. As a result, as shown in FIG. 1 and FIG. 3B, the upper permanent magnet portion 53 and the lower permanent magnet portion 54 are shafts via the buffer member 4 formed integrally with the inner peripheral iron core 3 around the shaft 2. 2 and the rotor 1 is assembled.

  As shown in FIGS. 4 and 5, the permanent magnet motor M includes the rotor 1 and the stator 7 described above. The stator 7 includes a stator core 71, an insulator 72, and a stator winding 73. The stator core 71 is formed in a cylindrical shape by laminating a plurality of thin steel plates, and includes an annular back yoke portion 711 and a plurality of teeth portions 712 extending from the back yoke portion 711 toward the inner diameter side. An insulator 72 is integrally formed on the stator core 71, and a stator winding 73 is wound around the teeth portion 712 via the insulator 72.

  The stator 7 configured as described above is formed by molding the stator core 71 around which the stator winding 73 is wound, with a mold resin except for the front end surface 7121 of the teeth portion 712 (the inner peripheral surface of the stator core 71). The cylindrical outer shell 74 is formed by molding, and the distal end surface 7121 of the tooth portion 712 is disposed so as to face the outer peripheral side of the rotor 1 with a predetermined interval (so-called air gap).

  According to the rotor 1 and the permanent magnet motor M using the rotor 1 according to the embodiment described above, the shock-absorbing member 4 is attached to the inner peripheral side iron core 3 in advance before attaching the permanent magnet portion 5 to the rotor 1. When the rotor 1 is assembled, the upper permanent magnet portion 53 and the lower permanent magnet portion 54 that are divided in the axial direction are fitted to the buffer member 4. Thereby, the permanent magnet part 5 is not influenced by the heat at the time of integral molding of the buffer member 4 as compared with the case where the buffer member 4 is integrally molded between the shaft 2 and the permanent magnet part 5. 5 can be easily assembled while preventing demagnetization of 5. In addition, the manufacturing cost of the rotor 1 can be reduced because a small injection mold is required as compared with the case where the buffer member 4 is integrally formed between the shaft 2 and the permanent magnet portion 5. Furthermore, even when the axial length of the permanent magnet motor M is changed, an injection mold can be used in common, and the upper permanent magnet portion 53 and the lower permanent that cover the outer peripheral side of the buffer member 4 can be used. It is only necessary to change the length of the magnet portion 54 in the axial direction.

  The upper permanent magnet portion 53 includes a plurality of first permanent magnets 534 arranged in the circumferential direction of the outer peripheral side upper iron core 531, and the lower permanent magnet portion 54 is a plurality of arranged in the circumferential direction of the outer peripheral side lower iron core 541. Therefore, the upper permanent magnet portion 53 and the lower permanent magnet portion 54 have the same shape, and a common member can be used. The first permanent magnet 534 and the second permanent magnet 544 are magnetized after the rotor 1 is assembled.

  The permanent magnet unit 5 includes an upper permanent magnet unit 53 and a lower permanent magnet unit 54. Since the upper end surface 51 of the outer periphery side first upper iron core 532 of the upper permanent magnet portion 53 and the lower end surface 52 of the outer periphery side first lower iron core 542 of the lower permanent magnet portion 54 are respectively pressed by the end plates 6, the permanent magnet portion 5 Can be fixed to the shaft 2 in contact with the buffer member 4.

  Next, the rotor 1 according to the second embodiment will be described with reference to FIGS. Note that the same reference numerals are given to the same components as those in the first embodiment described above, and the description thereof is omitted. As shown in FIGS. 6 to 9, the rotor 1 is replaced with the upper permanent magnet portion 53 and the lower permanent magnet portion 54 of the permanent magnet portion 5 of the first embodiment described above, for example, the magnet powder is made of resin. The inner peripheral iron core 3 is provided with an upper permanent magnet portion 55 and a lower permanent magnet portion 56 formed of solidified so-called plastic magnets so as to cover the outer peripheral surface 32, the upper surface 33 and the lower surface 34 of the inner peripheral iron core 3. The shock-absorbing member 9 is integrally formed. As shown in FIG. 7, the outer periphery of the buffer member 9 is formed in, for example, an octagonal cross section.

  The upper permanent magnet portion 55 and the lower permanent magnet portion 56 are each formed in a cylindrical shape, the inner peripheral side is formed in an octagonal shape so as to correspond to the sectional octagonal shape of the buffer member 9, and the outer peripheral side is formed in a circular cross section. ing. The cushion member 9 having an octagonal cross section is brought into contact with the upper permanent magnet portion 55 and the lower permanent magnet portion 56 having an octagonal cross section, so that the permanent magnet portion 5 does not idle (idle) with respect to the shaft 2 and is permanent. The rotational torque of the magnet unit 5 is reliably transmitted to the shaft 2.

  The upper permanent magnet portion 55 is fitted to the buffer member 9 from the upper surface 91 side of the buffer member 9 as shown by an arrow b in FIG. 9, so that the lower surface 551 of the upper permanent magnet portion 55 is the upper surface 91 of the buffer member 9. In contact with the outer periphery of the buffer member 9. The lower permanent magnet portion 56 is fitted to the buffer member 9 from the lower surface 92 side of the buffer member 9 as indicated by an arrow a in FIG. 9, so that the upper surface 561 of the lower permanent magnet unit 56 is the buffer member 9. It contacts the lower surface 92 and contacts the outer periphery of the buffer member 9. The upper permanent magnet portion 55 and the lower permanent magnet portion 56 that are in contact with each other so as to cover the buffer member 9 are, for example, similar to the first embodiment described above, the upper end surface 552 of the upper permanent magnet portion 55 and the lower permanent magnet portion 55. The lower end surfaces 562 of the side permanent magnet portions 56 are respectively pressed by the end plates 6. Alternatively, the upper permanent magnet portion 55 and the lower permanent magnet portion 56 are bonded to each other by ultrasonic bonding. As a result, as shown in FIG. 8, the upper permanent magnet portion 55 and the lower permanent magnet portion 56 are fixed to the shaft 2 via the buffer member 9 formed integrally with the inner peripheral iron core 3 around the shaft 2, The rotor 1 is assembled. The upper permanent magnet portion 55 and the lower permanent magnet portion 56 are magnetized after the rotor 1 is assembled.

  The upper permanent magnet portion 55 and the lower permanent magnet portion 56 are each formed in a cylindrical shape, and the inner peripheral side is formed in an octagonal cross section. However, the present invention is not limited to this, and the inner peripheral side shape and the upper The shape of the contact portion between the permanent magnet portion 55 and the lower permanent magnet portion 56 can be changed as appropriate.

  According to the rotor 1 according to the second embodiment configured as described above, the permanent magnet portion 5 can be easily assembled while preventing demagnetization, as in the first embodiment described above. The manufacturing cost of the child 1 can be suppressed. Further, even when the axial length of the permanent magnet motor M is changed, the shape of the buffer member 9 is not changed, and the upper permanent magnet portion 55 and the lower permanent magnet portion 56 that cover the outer peripheral side of the buffer member 9 are changed. It is only necessary to change the axial length. Furthermore, in the first embodiment described above, the outer peripheral side upper iron core 531 and the outer peripheral side lower iron core 541 are required, but in the second embodiment, the outer peripheral side upper iron core and the outer peripheral side lower iron core are unnecessary. Furthermore, the number of parts can be reduced.

DESCRIPTION OF SYMBOLS 1 Rotor 2 Shaft 3 Inner peripheral side core 31 1st convex part 32 Outer peripheral surface 33 Upper surface 34 Lower surface 4 Buffer member 41 2nd convex part 42 Upper end surface 43 Lower end surface 5 Permanent magnet part 51 Upper end surface 52 Lower end surface 53 Upper permanent magnet Portion 531 Outer peripheral upper iron core 532 Outer peripheral first upper iron core 532 'Upper contact portion 532a Lower surface 533 Outer peripheral second upper iron core 533a Recessed portion 533b Lower end surface 534 First permanent magnet 54 Lower permanent magnet portion 541 Outer peripheral lower core 542 Outer peripheral side first lower iron core 542 ′ Lower contact portion 542a Upper surface 543 Outer peripheral side second lower iron core 543a Recessed portion 543b Upper end surface 544 Second permanent magnet 55 Upper permanent magnet portion 551 Lower surface 552 Upper end surface 56 Lower permanent magnet portion 561 Upper surface 562 Lower end surface 6 End plate 7 Stator 71 Stator core 711 Back yoke part 712 Teeth part 712 DESCRIPTION OF SYMBOLS 1 End surface 72 Insulator 73 Stator winding 74 Outer shell 9 Buffer member 91 Upper surface 92 Lower surface M Permanent magnet motor

Claims (4)

A rotor including a shaft, a columnar buffer member integrally formed around the inner peripheral iron core fixed to the shaft, and a cylindrical permanent magnet portion covering the outer peripheral side of the buffer member,
The permanent magnet portion includes an upper permanent magnet portion and a lower permanent magnet portion divided in the axial direction of the shaft,
The upper permanent magnet portion has an upper contact portion that contacts the upper end surface of the buffer member, and the lower permanent magnet portion has a lower contact portion that contacts the lower end surface of the buffer member. Rotor characterized by.   The upper permanent magnet part includes an outer peripheral upper iron core and a plurality of first permanent magnets arranged in the circumferential direction of the outer peripheral upper iron core, and the lower permanent magnet part is the outer peripheral lower iron core and the outer peripheral lower iron core. The rotor according to claim 1, further comprising a plurality of second permanent magnets arranged in the circumferential direction.   The rotor according to claim 1 or 2, wherein both end faces in the axial direction of the permanent magnet portion are pressed by an annular end plate. A permanent magnet electric motor comprising: the rotor according to any one of claims 1 to 3; and a stator arranged to face the outer peripheral side of the rotor at a predetermined interval.

Images