JP6322954B2 - Rotor - Google Patents

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. It is applied as a brushless DC motor for rotational driving.

  In the rotor of such a permanent magnet motor, one buffer member is fitted between the rotor core fixed to the shaft and the permanent magnet disposed on the outer peripheral side of the rotor core, and the buffer member is disposed in both directions of the shaft axis. Are pressed by two pressing plates, and the center side of each pressing plate is crimped and fixed to the shaft. Due to the structure of the rotor, it is known that vibration due to the rotation of the permanent magnet is absorbed by the buffer member and is not transmitted from the permanent magnet to the rotor core or the shaft, and the vibration isolation effect of the rotor can be obtained (for example, patents) Reference 1). However, since the rotor by patent document 1 has the process of fitting a buffer member between a rotor core and a permanent magnet, the assembly man-hour of a rotor will start.

  Therefore, as a rotor of a permanent magnet motor that can reduce the number of man-hours for assembling the rotor, there is one that is integrally formed by filling a space between the shaft and the permanent magnet with a special rubber cushioning member (for example, , See Patent Document 2). In the rotor according to Patent Document 2, since the buffer member is integrally formed with the shaft and the permanent magnet, the step of fitting the buffer member between the shaft and the permanent magnet is eliminated, thereby reducing the number of steps for assembling the rotor. Can do. However, the permanent magnet may be demagnetized by the heat at the time of integral molding of the buffer member. In addition, there is a problem that the mold for injection molding for integrally molding the buffer member into the shaft and the permanent magnet is enlarged.

JP 2001-186700 A JP 2001-327105 A

In view of the above problems, an object of the present invention is to provide a rotor that can reduce the number of rotor assembly steps while preventing demagnetization of a permanent magnet.

In order to solve the above-described problems, a rotor according to the present invention includes a shaft, a shock-absorbing member integrally formed around the shaft, and a cylindrical permanent magnet portion disposed on the outer peripheral side of the shock-absorbing member. The buffer member is inserted into the inner peripheral side of the permanent magnet portion together with the shaft, and the shaft is covered with a buffer member having an outer diameter larger than the inner diameter of the permanent magnet portion in at least a part of the shaft in the axial direction. A plate-like member is provided .

According to the rotor of the present invention, since the buffer member is integrally molded around the shaft, the heat at the time of the integral molding is not transmitted to the permanent magnet portion, and when assembling the rotor, the buffer member is combined with the shaft. Since it is only necessary to insert it into the permanent magnet portion, it is possible to reduce the number of assembling steps of the rotor while preventing demagnetization of the permanent magnet. In addition, since the buffer member is integrally formed with the shaft in advance, a smaller mold for injection molding can be used as compared with the case where the buffer member, the shaft, and the permanent magnet portion are integrally formed.

It is explanatory drawing which shows the rotor by this invention, (a) is a side view, (b) is a top view, (c) is a bottom view. FIG. 4 is a cross-sectional view of the rotor according to the present invention taken along the line A-O-A shown in FIG. It is BB sectional drawing shown to Fig.1 (a) of the rotor by this invention. It is CC sectional drawing shown to Fig.1 (a) of the rotor by this invention. It is DD sectional drawing shown to Fig.1 (a) of the rotor by this invention. It is a disassembled sectional view which shows the rotor by this invention. 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. FIG. 4 is a cross-sectional view taken along line A-O-A shown in FIG. 1B of a rotor according to another embodiment, and corresponds to a cross-section taken along line E-O-E shown in FIG. 3. It is sectional drawing which shows the case where a buffer member is integrally formed in a shaft so that a plate-shaped member may be covered in the state except the permanent magnet part of the rotor by other embodiment. It is sectional drawing which shows the case where a buffer member is integrally formed in a shaft so that a rotation prevention part may be covered in the state except the permanent magnet part of the rotor by other embodiment.

  Embodiments of the present invention will be described below in detail with reference to the accompanying drawings. FIGS. 1 to 11 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 electric motor in which a rotor having a permanent magnet is rotatably arranged in a stator that generates a rotating magnetic field. This is applied to the brushless DC motor. 2 and 9 are cross-sectional views taken along the line A-O-A shown in FIG. 1B, and represent a portion that is symmetrical with respect to the central axis O corresponding to the cross-section E-O-E shown in FIG. Yes.

  As shown in FIGS. 1 and 2, the rotor 1 is disposed on the outer peripheral side of the shaft 2, a buffer member 3 made of a member such as rubber or elastomer integrally formed around the shaft 2, and the buffer member 3. And an annular permanent magnet portion 4 and a pressing plate 5 for pressing the buffer member 3 from the axial direction of the shaft 2. The buffer member 3 formed integrally with the shaft 2 is inserted into the inner peripheral side of the permanent magnet portion 4 together with the shaft 2. The shaft 2 is integrally formed with the plate-like member 21 that presses the permanent magnet portion 4 from the axial direction on the upper side in the axial direction of the shaft 2, and the plate-like member 21 on the lower side in the axial direction of the shaft 2. An idling prevention unit 22 for transmitting the rotational torque of the permanent magnet unit 4 to the shaft 2 is provided so as not to idle (idle) with respect to the shaft 2. The plate-like member 21 and the idling prevention portion 22 are covered with a buffer member 3 with the shaft 2 being press-fitted and fixed at the center thereof.

  The permanent magnet portion 4 is, for example, a cylindrical permanent magnet 41 obtained by sintering magnet powder, and a magnetic steel plate that is formed shorter than the permanent magnet 41 in the axial direction of the shaft 2 and arranged on the inner peripheral side of the permanent magnet 41. And a cylindrical yoke portion 42 in which are stacked. The permanent magnet 4 may be configured by arranging plate-like permanent magnet pieces in a cylindrical shape (not shown). 2 and 3, the yoke portion 42 is formed in a circular cross section so that the outer peripheral side corresponds to the inner peripheral shape of the permanent magnet 41, and the inner peripheral side is a cross section of the small-diameter portion 31 of the buffer member 3 described later. It is formed in a pentagonal cross section so as to correspond to a pentagonal column shape. The yoke portion 42 has an upper end surface 42a that abuts on a first large diameter portion 32 of the buffer member 3 described later and a lower end surface 42b that abuts on a second large diameter portion 33 of the buffer member 3 described later. The plate-like member 21 is formed in a disc shape and has an outer diameter b larger than the inner diameter a of the yoke part 42 of the permanent magnet part 4. The anti-spinning portion 22 is formed in a pentagonal column shape in cross section and has an outer diameter c smaller than the inner diameter a of the yoke portion 42 of the permanent magnet portion 4.

  As shown in FIGS. 1 to 5, the buffer member 3 includes a small diameter portion 31, a first large diameter portion 32, and a second large diameter portion 33. As shown in FIGS. 2 and 3, the small-diameter portion 31 is formed so as to cover the periphery of the anti-spinning portion 22 having a pentagonal columnar section and to have a pentagonal section. The small diameter portion 31 is inserted on the inner peripheral side of the yoke portion 42 of the permanent magnet portion 4 formed in a pentagonal cross section. As shown in FIGS. 1B, 2, and 3, the first large-diameter portion 32 is formed so as to cover the periphery of the disk-shaped plate-shaped member 21 and to have a disk shape. The first large diameter portion 32 is integrally formed at the upper end in the axial direction of the small diameter portion 31 and has an outer diameter e formed so as to be larger in the radial direction than the outer diameter d of the small diameter portion 31. doing. The 2nd large diameter part 33 is comprised by the some fan-shaped part 33a provided in the circumferential direction, as shown in FIG.1 (c), FIG.2 and FIG.5. The second large-diameter portion 33 is integrally formed at the lower end in the axial direction of the small-diameter portion 31 via a connecting portion 34 described later, and is larger than the maximum radius d1 from the central axis O to the outer periphery of the small-diameter portion 31. The outer diameter f is formed to be large. As shown in FIGS. 2, 4, and 5, the connecting portion 34 is formed in a columnar shape so as to integrally connect the small diameter portion 31 and the second large diameter portion 33 along the axial direction. The connecting portion 34 has an outer diameter g formed to be smaller than a length 2d2 that is twice as long as d2, where d2 is a minimum radius from the central axis O to the outer periphery of the small diameter portion 31. . Accordingly, when the connecting portion 34 is deformed so that the second large-diameter portion 33 extends along the shaft 2, the root 33 b of the second large-diameter portion 33 has a small-diameter portion on the inner peripheral side of the yoke portion 42 having the inner diameter a. There is no hindrance when inserting 31.

  As shown in FIG. 1C and FIG. 2, the holding plate 5 is formed in a disc shape that covers the second large diameter portion 33 of the buffer member 3 from the axial direction of the shaft 2, and from the inner diameter h of the permanent magnet 41. The outer diameter i is smaller than the outer diameter f of the second large diameter portion 33. The presser plate 5 has four caulking portions 51 in a portion close to the shaft 2 and is crimped and fixed to the shaft 2 by caulking and deforming the caulking portions 51.

  The procedure for assembling the rotor 1 configured as shown in FIG. 2 will be described with reference to FIG. As shown in FIG. 6, the second large diameter portion 33 of the buffer member 3 is bent in the axial direction of the shaft 2 so as to be smaller in the radial direction than the inner diameter a of the yoke portion 42 as indicated by a dotted arrow. Next, the small diameter portion 31 of the buffer member 3 together with the shaft 2 is inserted into the inner peripheral side of the yoke portion 42 of the permanent magnet portion 4, and the first large diameter portion 32 of the buffer member 3 is inserted into the yoke portion 42 of the permanent magnet portion 4. It abuts on the upper end surface 42a. Thereafter, the second large diameter portion 33 of the buffer member 3 is expanded in the radial direction, and the state before the second large diameter portion 33 is bent (the second large diameter portion 33 in the solid line) is returned. Next, the pressing plate 5 is inserted into the shaft 2, the pressing plate 5 is pressed against the second large diameter portion 33 of the buffer member 3, and the caulking portion 51 is crimped to press the pressing plate 5 to the shaft 2.

  As a result, the first large diameter portion 32 of the buffer member 3 is pressed against the upper end surface 42 a of the yoke portion 42, and the second large diameter portion 33 of the buffer member 3 is pressed against the lower end surface 42 b of the yoke portion 42. As a result, as shown in FIG. 2, the rotor 1 is assembled in which the permanent magnet portion 4 is fixed to the shaft 2 via the buffer member 3 formed integrally with the shaft 2. At this time, if the buffer member 3 is compressed in the axial direction by the plate-like member 21 and the pressing plate 5, the outer diameter side of the smaller diameter part 31 is the inner peripheral side of the yoke part 42. The permanent magnet portion 4 is more firmly fixed to the shaft 2 in contact with the shaft 2.

  As shown in FIGS. 7 and 8, the permanent magnet motor M includes the rotor 1 and the stator 6 described above. The stator 6 includes a stator core 61, an insulator 62, and a stator winding 63. The stator core 61 is formed in a cylindrical shape by laminating a plurality of thin steel plates, and includes an annular back yoke portion 611 and a plurality of teeth portions 612 extending from the back yoke portion 611 to the inner diameter side. An insulator 62 is formed integrally with the stator core 61, and a stator winding 63 is wound around the teeth portion 612 via the insulator 62.

  The stator 6 thus configured is molded with a mold resin except for the tip surface 6121 of the teeth portion 612 (the inner peripheral surface of the stator core 61) of the stator core 61 around which the stator winding 63 is wound. A cylindrical outer shell 64 is formed by molding, and the tip surface 6121 of the tooth portion 612 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 buffer member 3 is integrally formed around the shaft 2 in advance. Thereby, when assembling the rotor 1, the permanent magnet 41 of the permanent magnet portion 4 is more integrally formed with the buffer member 3 than when the buffer member 3 is integrally formed between the shaft 2 and the permanent magnet portion 4. The buffer member 3 can be simply inserted into the permanent magnet portion 4 together with the shaft 2 without being affected by the heat of the rotor. Therefore, the assembly man-hour of the rotor 1 can be reduced while preventing the demagnetization of the permanent magnet 41 of the permanent magnet portion 4. Can be reduced. Further, since the buffer member 3 is integrally formed around the shaft 2 in advance, a smaller mold for injection molding is used compared to the case where the buffer member 3 is integrally formed between the shaft 2 and the permanent magnet portion 4. be able to.

  Further, a plate-like member 21 covered with a buffer member 3 having an outer diameter b larger than the inner diameter a of the yoke portion 42 of the permanent magnet portion 4 is provided on the upper side in the axial direction of the shaft 2. Thereby, since the plate-shaped member 21 and the upper end surface 42a of the yoke part 42 are arrange | positioned so as to oppose an axial direction, it becomes the structure by which the buffer member 3 interposes between both. Therefore, the upper end surface 42 a of the yoke portion 42 can be pressed by the plate-like member 21 through the buffer member 3.

  The plate-like member 21 further includes an anti-spinning portion 22 that prevents the permanent magnet portion 4 from spinning with respect to the shaft 2. The anti-spinning portion 22 is formed in a pentagonal section in cross section, and the outer periphery of the anti-spinning portion 22 is covered with the buffer member 3. The buffer member 3 is formed in a pentagonal cross section, and the permanent magnet portion 4 is fixed to the outer periphery of the buffer member 3. Therefore, the rotational force of the permanent magnet portion 4 is transmitted to the idling prevention portion 22 via the buffer member 3 so that the shaft 2 can be rotated.

  The buffer member 3 is integrally formed at both ends of the small diameter portion 31 in the axial direction of the shaft 2 of the small diameter portion 31 and the small diameter portion 31 inserted into the inner peripheral side of the yoke portion 42 of the permanent magnet portion 4. a first large-diameter portion 32 and a second large-diameter portion 33 having outer diameters e and f larger than d. The second large-diameter portion 33 has an outer diameter f larger than the outer diameter c of the anti-spinning portion 22. And is divided into multiple pieces in the circumferential direction. Thereby, when inserting the small diameter part 31 of the buffer member 3 into the yoke part 42 of the permanent magnet part 4, the second large diameter part 33 of the buffer member 3 is deformed in the axial direction of the shaft 2. Assembly can be performed easily.

  Furthermore, between the small diameter part 31 of the buffer member 3 and the second large diameter part 33, there is an outer diameter g smaller than the inner diameter a of the yoke part 42 of the permanent magnet part 4, and the small diameter part 31 of the buffer member 3 and A connecting portion 34 for connecting the second large diameter portion 33 is provided. Accordingly, when the connecting portion 34 is deformed so that the second large-diameter portion 33 extends along the shaft 2, the root 33 b of the second large-diameter portion 33 has a small-diameter portion on the inner peripheral side of the yoke portion 42 having the inner diameter a. There is no hindrance when inserting 31.

  Next, the rotor 1 according to the second embodiment will be described with reference to FIG. 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 FIG. 9, the rotor 1 includes a permanent magnet portion 7 formed of a so-called plastic magnet in which magnet powder is hardened with a resin, for example, instead of the permanent magnet portion 4 of the first embodiment described above. ing. The permanent magnet portion 7 is formed in the same shape as the permanent magnet portion 4 of the first embodiment, and includes an outer peripheral portion 71 and an inner peripheral portion 72 formed shorter than the outer peripheral portion 71 in the axial direction of the shaft 2. ing. The outer peripheral portion 71 is formed in a circular cross section on the outer diameter side, and the inner peripheral portion 72 is formed in a pentagonal cross section so as to correspond to the cross sectional pentagonal column shape of the small diameter portion 31 on the inner diameter side. The inner peripheral portion 72 has an upper end surface 72 a that contacts the first large diameter portion 32 and a lower end surface 72 b that contacts the second large diameter portion 33.

  Thereby, according to the rotor 1 by 2nd Embodiment, while the demagnetization of the permanent magnet part 7 can be prevented like the above-mentioned 1st Embodiment, while the assembly man-hour of the rotor 1 can be reduced. As compared with the case where the buffer member 3 is integrally formed including the permanent magnet portion 7, a smaller mold for injection molding can be used. Further, in the first embodiment described above, the permanent magnet portion 4 fits the yoke portion 42 to the permanent magnet 41, whereas in the second embodiment, the permanent magnet portion 7 is an integrally molded product. In addition, the rotor 1 can be easily assembled.

  Next, a rotor 1 according to a third embodiment will be described with reference to FIG. In addition, the same code | symbol is attached | subjected about the same structure as the above-mentioned embodiment, and the description is abbreviate | omitted. As shown in FIG. 10, the rotor 1 is formed by integrally molding a buffer member 3 on the shaft 2 so as to cover a plate-like member 23 provided on the upper side in the axial direction of the shaft 2. Since there is no idling prevention part 22 of the first embodiment described above, the buffer member 3 is formed integrally with the shaft 2 in consideration of the hardness of a member such as rubber or elastomer, and the small diameter part 31 has a pentagonal cross section. The first large diameter portion 32 is formed in a disc shape. Thereby, according to the rotor 1 by 3rd Embodiment, the effect similar to the above-mentioned 1st Embodiment can be acquired.

  Next, a rotor 1 according to a fourth embodiment will be described with reference to FIG. In addition, the same code | symbol is attached | subjected about the same structure as the above-mentioned embodiment, and the description is abbreviate | omitted. As shown in FIG. 11, the rotor 1 is formed by integrally forming the buffer member 3 on the shaft 2 so as to cover the idling prevention portion 24 provided on the lower side in the axial direction of the shaft 2. Since the plate-like member 21 of the first embodiment is not provided, the buffer member 3 is integrally formed with the shaft 2 in consideration of the hardness of a member such as rubber or elastomer, and the small-diameter portion 31 has a pentagonal cross-sectional shape. The first large diameter portion 32 is formed in a disc shape. Further, the anti-spinning portion 24 is formed in a pentagonal cross section. Thereby, according to the rotor 1 by 4th Embodiment, the effect similar to the above-mentioned 1st Embodiment can be acquired.

  According to the first to fourth embodiments described above, the anti-spinning portions 22, 24, the small-diameter portion 31, and the yoke portion 42 are each formed in a pentagonal cross section. The cross-sectional polygonal shape is not limited as long as the rotational torque of the permanent magnet portion 4 can be reliably transmitted to the shaft 2. Here, the polygonal cross section includes a shape other than a pentagonal shape, for example, a quadrangular shape, a hexagonal shape, a D-cut shape, etc. Including various shapes.

  Moreover, according to 1st Embodiment, although the plate-shaped member 21 and the rotation prevention part 22 were integrally molded, you may make it form this invention not only in this but in a different body. Furthermore, the axial lengths of the permanent magnet 41 and the yoke portion 42 or the axial lengths of the outer peripheral portion 71 and the inner peripheral portion 72 may be formed to the same length.

DESCRIPTION OF SYMBOLS 1 Rotor 2 Shaft 21, 23 Plate-shaped member 22, 24 Anti-rotation part 3 Buffer member 31 Small diameter part 32 1st large diameter part 33 2nd large diameter part 33a Fan-shaped part 33b Base 34 Connection part 4 Permanent magnet part 41 Permanent Magnet 42 Yoke part 42a Upper end face 42b Lower end face 5 Holding plate 51 Caulking part 6 Stator 61 Stator core 611 Back yoke part 612 Teeth part 6121 End face 62 Insulator 63 Stator winding 64 Outer part 7 Permanent magnet part 71 Outer part 72 Inner peripheral part 72a Upper end surface 72b Lower end surface M Permanent magnet motor

Claims (3)

A rotor including a shaft, a buffer member integrally molded around the shaft, and a cylindrical permanent magnet portion disposed on the outer peripheral side of the buffer member,
The buffer member together with the shaft is inserted into the inner peripheral side of the permanent magnet portion ,
The rotor, wherein the shaft includes a plate-like member covered with the buffer member having an outer diameter larger than an inner diameter of the permanent magnet portion at least in a part of the shaft in the axial direction . The plate-shaped member is formed of at least a part of the shaft in the axial direction between the shaft and the polygonal columnar permanent magnet portion covered with the buffer member having an outer diameter smaller than the inner diameter of the permanent magnet portion. The rotor according to claim 1 , further comprising an anti-spinning portion. The buffer member is integrally formed with a small-diameter portion to be inserted on the inner peripheral side of the permanent magnet portion and both axial ends of the shaft of the small-diameter portion, and has an outer diameter larger than the outer diameter of the small-diameter portion. A pair of large diameter portions ,
Of the pair of large diameter portions, one large diameter portion has an outer diameter larger than the outer diameter of the anti-spinning portion, and is divided into a plurality in the circumferential direction .
The small-diameter portion and the one large-diameter portion are integrally formed with the shaft, have an outer diameter smaller than the inner diameter of the permanent magnet portion, and connect the small-diameter portion and the one large-diameter portion. The rotor according to claim 2, further comprising a connecting portion.

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