JP2008301667A - Double stator type motor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a double stator type motor 10 having such fitting structure of a permanent magnet 56 as the permanent magnet 56 is rigidly fixed in a through hole 55 of a rotor 50, with assembly work being easy. <P>SOLUTION: A holder 100 is provided in which the permanent magnet 56 is stored and fixed, which is inserted in the through hole 55 for fixing. The holder 100 is provided with a first regulating part 103 and a second regulating part 105 which, when inserted and fixed in the through hole, contact to a rotor body 51 to regulate movement of the holder 100 in the inserting direction. Since the permanent magnet 56 is stored and fixed in the holder 100 and then the holder 100 is inserted and fixed in the through hole 55, the permanent magnet 56 is rigidly fixed to the rotor 50 compared to such fitting structure as the permanent magnet 56 is directly fitted in the through hole 55 or bonded with an adhesive. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a double stator motor.

  As one type of double stator type motor, Japanese Patent Application Laid-Open No. 3-139156 describes a double stator type motor in which a shaft, a rotor, an outer stator and an inner stator are built in a motor housing. In this double stator type motor, a shaft is rotatably incorporated in a motor housing via a bearing portion, and the rotor is coupled to rotate integrally with the shaft. Then, the outer stator is fixed to the motor housing so as to be positioned on the outer side in the rotational radial direction with respect to the rotor, and the inner stator is fixed on the motor housing so as to be positioned on the inner side in the rotational radial direction with respect to the rotor.

The rotor in this double stator type motor is provided with a circumferential surface having a circular cross section or a regular polygon. And the through-hole which penetrates the inside and outside of a rotor is arranged in the circumferential direction at this peripheral surface, and the flat permanent magnet is fitted to each through-hole. Each permanent magnet is arranged such that its outer surface faces the outer stator and its inner surface faces the inner stator.
JP-A-3-139156

  By the way, a large centrifugal force acts on the permanent magnet as the rotor rotates at a high speed, and an attractive and repulsive force acts between the permanent magnet and the stator coil. As in the conventional double stator type motor described above, in the mounting structure in which the permanent magnet is simply fitted into the through hole or in the mounting structure in which the adhesive is bonded and fixed to the through hole with an adhesive, the permanent magnet is subjected to centrifugal force during high-speed rotation of the rotor. There is a risk of dropping from the through hole due to attraction and repulsion between the stator coils.

  In view of the above problems, an object of the present invention is to provide a double stator motor having a permanent magnet mounting structure in which a permanent magnet can be firmly fixed in a through hole of a rotor and an assembling operation is easy.

  In order to achieve the above object, an invention according to claim 1 is directed to a shaft rotatably incorporated in a motor housing via a bearing portion, a rotor connected to rotate integrally with the shaft, and a rotor. An outer stator fixed to the housing so as to be positioned on the outer side in the rotational radial direction, and an inner stator fixed to the housing so as to be positioned on the inner side in the rotational radial direction with respect to the rotor. It has a regular polygonal peripheral surface, and through holes that penetrate the inner and outer sides of the rotor are arranged in the peripheral direction on the peripheral surface, permanent magnets are attached to the respective through holes, and the outer surface of the permanent magnet faces the outer stator. A double stator motor that is arranged so that the inner surface of the permanent magnet faces the inner stator, and stores and fixes the permanent magnet And a holder that is inserted and fixed in the through hole, and the holder is provided with a restricting portion that contacts the rotor body and restricts movement of the holder in the insertion direction when the holder is inserted and fixed in the through hole. It is characterized by that.

  According to a second aspect of the present invention, in the double stator type motor according to the first aspect, the restricting portion contacts the side surface of the rotor body on the inner stator side and the outer stator side of the rotor body. It has the 2nd control part which contacts the side surface of this.

  According to a third aspect of the present invention, in the double stator motor according to the second aspect, at least one of the first restricting portion or the second restricting portion has elasticity, and the one restricting portion is elastically deformed. The holder is inserted into the through hole while the one restricting portion is in contact with a surface in the rotational radius direction of the rotor body that is different from the insertion direction in which the holder is inserted.

  According to a fourth aspect of the present invention, in the double stator type motor according to the second aspect, at least one of the first restricting portion and the second restricting portion has flexibility, and the restriction of the one By bending the portion, the one restricting portion comes into contact with a surface that is different in the rotational radius direction of the rotor body from the direction in which the holder is inserted.

  According to a fifth aspect of the present invention, in the double stator type motor according to the first, second, third, or fourth aspect, the first restricting portion has a planar shape, and the holder is connected to the through-hole on the inner stator side. The first restricting portion is locked to the inner stator side surface of the rotor body.

  A sixth aspect of the present invention is the double stator type motor according to the first, second, third, fourth or fifth aspect, wherein the permanent magnet is fixed to a holder with an adhesive.

  A seventh aspect of the present invention is the double stator type motor according to the first, second, third, fourth or fifth aspect, wherein the holder is fixed to the inner wall surface of the through hole with an adhesive.

  The invention according to claim 8 is the double stator type motor according to claim 1, 2, 3, 4, 5, 6 or 7, wherein the holder is press-formed from a single metal plate.

  According to the first aspect of the present invention, the permanent magnet is stored and fixed in the holder, and the holder is inserted and fixed in the through hole. Therefore, the permanent magnet is directly fitted into the through hole, or an adhesive is used. The permanent magnet can be firmly fixed to the rotor as compared to the fixing mounting structure. In addition, since the restriction portion is provided on the holder, the operation of attaching the permanent magnet to the through hole is also simplified.

  According to the invention described in claim 2, since the holder inserted into the through hole is restricted from moving toward the outer stator side and toward the inner stator side by both restricting portions, the permanent magnet is more firmly formed into the through hole. Can be fixed.

  According to the third aspect of the present invention, the permanent magnet can be attached to the through hole by a simple operation of inserting the holder into the through hole while elastically deforming one of the restricting portions.

  According to the fourth aspect of the present invention, the permanent magnet can be attached to the through hole by a simple operation of storing the permanent magnet in the holder, inserting the holder into the through hole, and bending one of the restricting portions.

  According to the invention described in claim 5, since the contact area between the first restricting portion and the rotor body is increased, the movement of the holder toward the outer stator side even if a large centrifugal force is applied to the holder during high-speed rotation of the motor. Can be reliably regulated.

  According to the sixth aspect of the present invention, since the permanent magnet stored in the holder is bonded to the holder with the adhesive, it is possible to reliably prevent rattling in the holder.

  According to the seventh aspect of the present invention, since the holder is bonded to the through hole by the adhesive, the permanent magnet can be more firmly fixed to the through hole. Further, when the holder is mounted in the through hole, the holder can be prevented from being detached from the through hole by being attracted by the permanent magnet of the adjacent through hole, and the mounting operation of the holder is facilitated.

  According to the eighth aspect of the invention, since the holder is manufactured by punching and bending with a press, the manufacturing cost can be greatly reduced.

  The present invention will be described below with reference to the accompanying drawings. FIG. 1 is a sectional view showing a double stator motor according to an embodiment of the present invention. The double stator motor 10 includes a motor housing 20 and a wheel shaft 30. The wheel shaft 30 passes through the motor housing 20, and a wheel 40 is connected to a hub 31 integrally formed at one end protruding from the housing 20 by a hub stud bolt 41.

  The motor housing 20 includes an outer housing 21 whose inner end surface is an opening 21a, and an inner housing 22 that covers the inner end surface opening 21a of the outer housing 21, and the inner housing 22 is fixed to the outer housing 21 with bolts (not shown). . The inner housing 22 is attached to the vehicle body via a vehicle suspension device (not shown). The outer housing 21 and the inner housing 22 are formed with through holes 21 b and 22 a in the center, respectively, and the hub shaft 30 is inserted into the motor housing 20 from the through hole 21 b of the outer housing 21.

  The housing 20 includes a rotor 50, a pair of ball bearings 61 and 62 that rotatably support the rotor 50, an outer stator 70, and an inner stator 80. As shown in FIG. 2, the rotor 50 includes a bottomed short cylindrical rotor main body 51 and a cylindrical shaft portion 53 that protrudes integrally at the center of the bottom surface 52 of the rotor main body 51. The rotor body 51 has a circumferential surface 54 having a circular cross section, and a plurality of through holes 55 penetrating the inside and outside of the rotor are arranged in the circumferential surface 54 at equal intervals along the circumferential direction. The through hole 55 is formed in a rectangular shape having a side parallel to the rotation center line O of the rotor 50 as a long side. A holder 100 storing a rectangular flat permanent magnet 56 is fitted into each through hole 55.

  FIG. 4 shows an enlarged detail of the structure of the holder 100. The holder 100 is manufactured by punching a single metal plate of a nonmagnetic material into a predetermined shape and bending it. The holder 100 is provided with a shape that fits into the through hole 55 of the rotor 50, that is, a rectangular outer support piece 101. A rectangular opening 101 a is formed at the center of the outer support piece 101. Foot pieces 102 are suspended from each of the opposing long side end portions of the outer support piece 101.

  A flat plate-like first restricting piece 103 that is bent at a right angle and protrudes outward of the outer support piece 101 in parallel with the outer support piece 101 is connected to the lower end of each foot piece 102. Inner support pieces 104 are continuously provided at both ends in the longitudinal direction of the first restricting piece 103 so as to be bent at right angles and to protrude inward of the outer support piece 101 in parallel with the outer support piece 101. The outer support piece 101, the foot piece 102, and the inner support piece 104 define an insertion port 100a and a storage portion 100b into which the permanent magnet 56 is inserted.

  At the four corners of the outer support piece 101, there are provided second restricting pieces 105 having spring properties that are bent so as to expand outward of the outer support piece 101. A slit 100 c is formed between the second restriction piece 105 and the foot piece 102.

  The structure of the holder 100 is as described above. As shown in FIGS. 5 and 6, an adhesive is applied to the longitudinal side surface 56a of the permanent magnet 56, and the permanent magnet 56 coated with the adhesive is inserted from the insertion port 100a. Insert and store in the storage unit 100b. A side surface 56 a of the stored permanent magnet 56 is bonded to the foot 102 of the holder 100. Further, most of the outer surface of the permanent magnet 56 is exposed from the opening 101 a of the outer support piece 101. When the permanent magnet 56 coated with the adhesive is inserted from the insertion port 100a, the excess adhesive is scraped off from the side surface of the permanent magnet 56 at the longitudinal end of the foot 103 and collected in the slit 100c.

  Next, an adhesive is applied to the outer surface of the foot piece 102 of the holder 100 in which the permanent magnet 56 is stored, and the holder 100 to which the adhesive is applied is inserted into the through hole 55 of the rotor 50 from the inside and fitted. At this time, since the second restricting piece 105 is elastically deformed inward of the outer support piece 101, it can be passed without being caught in the through hole 55. When the second restricting piece 105 passes through the through hole 55, as shown in FIGS. 7 and 8, the second restricting piece 105 is restored outward and the tip thereof is locked to the outer wall surface on the outer stator 70 side of the rotor 50 body. On the other hand, the first restricting piece 103 is locked to the inner wall surface of the inner stator 80 of the rotor 50 main body. Then, the foot piece 102 is bonded to the inner wall surface of the through hole 55 with an adhesive. Further, the insertion opening 100 a of the holder 100 is blocked by the inner wall surface in the short direction of the through hole 55. When the holder 100 is inserted into the through hole 55, the excess adhesive applied to the foot piece 102 is scraped off by the inner wall surface in the longitudinal direction of the through hole 55 and accumulates on the first regulating piece 103. In this way, the permanent magnet 56 is fixed to the holder 100, and the holder 100 storing the permanent magnet 56 is mounted in each through hole 55 of the rotor 50.

  Next, as shown in FIG. 1, the cylindrical shaft portion 53 of the rotor is inserted into both the ball bearings 61 and 62 so that the rotor 50 is rotatably assembled to the inner housing 22, and a fine nut 63 is further attached to the cylindrical shaft portion 53. By tightening, the ball bearings 61 and 62 are prevented from coming off from the cylindrical shaft portion 53.

  The wheel shaft 30 is inserted into the cylindrical shaft portion 53 of the rotor 50 that is rotatably incorporated in the housing 20 by both ball bearings 61 and 62, and the cylindrical shaft portion 53 and the wheel shaft 30 are serrated and coupled so as to rotate integrally. Yes. Thus, the rotor 50 and the wheel shaft 30 are rotatably incorporated into the housing 20 by the common ball bearings 61 and 62.

  The outer stator 70 includes a plurality of iron cores 71 and coils 72 wound around each iron core 71. On the other hand, a plurality of recesses 21 c are formed in a ring shape on the inner peripheral surface of the outer housing 21. Each iron core 71 constituting the outer stator 70 is fitted into the recess 21 c and is directly fixed to the inner peripheral surface of the outer housing 21. The outer stator 70 is located outside the rotational radius of the rotor 50 and is arranged and fixed on the inner peripheral surface of the outer housing 21 so as to be close to the outer surface of the permanent magnet 56.

  The inner stator 80 includes a plurality of iron cores 81 and coils 82 wound around the respective iron cores 81, and the iron core 81 is fixed to the inner housing with bolts (not shown). The inner stator 80 is positioned on the inner side of the rotor in the radial direction of rotation, and is disposed and fixed to the inner housing 22 via the bearing case 63 so as to be close to the inner surface of the permanent magnet 56.

  The structure of the double stator motor 10 according to the present embodiment is as described above. The permanent magnet 56 can be prevented from falling off the holder 100 by closing the insertion port 100a with the inner wall surface of the through hole 55. The dropout from the through hole 55 toward the outer stator 70 can be prevented by locking the first restricting piece 103 and the inner wall surface of the rotor 50. Furthermore, the falling from the through hole 55 of the holder 100 to the inner stator 80 side can be prevented by locking the second restricting piece 105 and the outer wall surface of the rotor 50.

  Thus, according to this embodiment, the permanent magnet 56 is stored in the holder 100, and the permanent magnet 56 is simply inserted and fitted into the through hole 55 while the second restricting piece 105 is elastically deformed. 56 can be mounted in the through hole 55.

  Further, since the permanent magnet 56 stored in the holder 100 is adhered to the foot 102 of the holder 100 with an adhesive, it is possible to reliably prevent the permanent magnet 56 from rattling in the holder 100. And since the surplus part of the adhesive applied to the side surface of the permanent magnet 56 is accumulated in the slit 100c and is not exposed to the outside of the through hole 55, the work of removing the surplus adhesive applied to the permanent magnet 56 can be omitted.

  Furthermore, since the foot piece 102 is bonded to the inner wall surface of the through hole 55, not only can the holder 100 be prevented from falling out of the through hole 55, but also when the holder 100 storing the permanent magnet 56 is attached to the through hole 55. It is possible to prevent the magnets from being attracted by the permanent magnets 56 of the adjacent through holes 55 and coming off from the through holes 55. Therefore, the mounting operation of the holder 100 in the through hole 55 is facilitated. And since the excess part of the adhesive applied to the foot piece 102 is accumulated in the first restricting piece 103, it is not exposed to the outside of the through hole 55. Therefore, the operation of removing the excess adhesive applied to the holder 100 can be omitted.

  In addition, since the holder 100 is manufactured by punching and bending with a press machine, the cost can be greatly reduced.

  Next, a holder 200 in a double stator motor according to another embodiment of the present invention is shown in FIG. The holder 200 includes a rectangular outer support piece 201 having a size and shape that fits into the through hole 55 of the rotor 50. A rectangular opening 201 a is formed at the center of the outer support piece 201. Further, two leg pieces 202 are suspended from both ends of the long side on each of the opposing long sides of the outer support piece 201.

  A first restricting piece 203 that is bent at a right angle and protrudes outward of the outer support piece 201 in parallel with the outer support piece 201 is connected to the lower end of each foot piece 202. An inner support piece 204 that protrudes inward of the outer support piece 201 is connected to one end of the first restriction piece 203 in parallel with the outer support piece 201. The outer support piece 201, the foot piece 202, and the inner support piece 204 define an insertion opening 200 a and a storage portion 200 b for the permanent magnet 56.

  A second restricting piece 205 is erected between the two leg pieces 202 suspended from one end of the outer support piece 201 so as to connect the both leg pieces 202, and an end portion 205a on the outer stator side thereof is an outer support piece. Projecting from the surface of 201. The second restricting piece 205 is formed with two slits 200c extending in parallel with the foot piece 202. The second restricting piece 205 has flexibility, and the flexibility to the outside of the outer support piece 201 is enhanced by the two slits 200c.

  The holder structure of the double stator type motor according to the present embodiment is as described above. The adhesive is applied to the side surface 56a of the permanent magnet 56, inserted into the storage portion 200c from the insertion port 200a, and stored, and the foot piece 202 is stored. A permanent magnet 56 is bonded to the substrate. Next, an adhesive is applied to the foot piece 205 of the holder 200 in which the permanent magnet 56 is stored, and the holder 200 is inserted into the through hole 55 until the first restricting piece 203 is locked to the inner wall surface of the rotor 50. Mating. As a result, the foot piece 205 of the holder 200 is bonded to the inner wall surface of the through hole 55. Subsequently, as shown by a two-dot chain line in FIG. 9, the end portion 205 a of the second restriction piece 205 is bent outward of the outer support piece 201, and the front side end portion 205 is locked to the outer wall surface of the rotor 50. As a result, the holder 200 is mounted in the through hole 55.

  According to this embodiment, the permanent magnet 56 can be prevented from falling off the holder 200 by closing the insertion opening 200 a with the inner wall surface of the through hole 55. Further, the falling from the through hole 55 of the holder 200 to the outer stator 70 side can be prevented by locking the first restricting piece 203 and the inner wall surface of the rotor 50. Furthermore, the drop-out from the through hole 55 of the holder 200 to the inner stator 80 side can be prevented by locking the front side end portion 205a bent outward of the second restricting piece 205 and the outer wall surface of the rotor 50.

  As described above, according to the present embodiment, the permanent magnet 56 is housed in the holder 200, the holder 200 is inserted into the through hole 55, and the front side end portion 205a of the second restricting piece 205 is simply bent outward. Thus, the permanent magnet 56 can be firmly fixed to the through hole 55.

In this embodiment, a flat magnet is used as the permanent magnet, but it is also possible to use a curved magnet or a magnet provided with irregularities on the surface or end.
Further, although the two foot pieces 102 are provided, the inner support piece 104 is connected to the foot piece so as to reach the other end from one end of the through hole, and the outer support piece 101 is provided. It is also possible to adopt a structure in which a second restricting piece 105 having a spring property is provided at the end of the half foot piece 102.
Furthermore, although the first restricting piece 103 and the second restricting piece 105 are provided on the same side surface of the holder 100, the second restricting piece may be provided on a side surface orthogonal to the side surface on which the first restricting piece 103 is provided.
Moreover, although the inner wall surface which a through-hole opposes was formed in parallel with each other, it is also possible to form the inner wall surface which opposes not in parallel but incline.
Furthermore, the inner support piece 104 can be omitted by fixing the permanent magnet 56 to the outer support piece 101 or the foot piece 102 with an adhesive.

It is sectional drawing which shows the double stator type motor which concerns on one Example of this invention. It is a perspective view which shows the rotor of the motor. It is a perspective view which shows the holder for attaching a permanent magnet to the rotor of the motor. It is explanatory drawing which shows the through-hole of the holder, a permanent magnet, and a rotor. It is explanatory drawing which shows the through-hole of the holder and rotor which stored the permanent magnet. It is explanatory drawing which shows the same holder with which the through-hole of the rotor was mounted | worn. It is a partial expanded sectional view which shows the same holder with which the through-hole of the rotor was mounted | worn. It is a perspective view which shows the other holder for attaching a permanent magnet to the rotor of the double stator type motor which concerns on the other Example of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Double stator type motor 20 ... Housing 21 ... Outer housing 22 ... Inner housing 30 ... Wheel shaft 40 ... Wheel 50 ... Rotor 51 ... Rotor main body 52 ... Rotor bottom surface 53 ... Cylindrical shaft part 54 ... Rotor peripheral surface 55 ... Through-hole 56 ... permanent magnets 61, 62 ... bearing 70 ... outer stator 80 ... inner stator 100, 200 ... holders 100a, 200a ... insertion ports 100b, 200b ... storage portions 101, 201 ... outer support pieces 102, 202 ... foot pieces 103, 203 ... First restriction pieces 104, 204 ... inner support pieces 105, 205 ... second restriction pieces

Claims (8)

A shaft rotatably incorporated in the motor housing via a bearing portion, a rotor connected to rotate integrally with the shaft, and fixed to the housing so as to be located on the outer side in the rotational radial direction with respect to the rotor An outer stator, and an inner stator fixed to the housing so as to be positioned on the inner side in the rotational radius of the rotor, the rotor having a circumferential surface having a circular or regular polygonal cross section, and the rotor on the circumferential surface Through-holes penetrating the inside and outside of the magnet are arranged in the circumferential direction, permanent magnets are attached to the respective through-holes, the outer surfaces of the permanent magnets are arranged so as to face the outer stator, and the inner surfaces of the permanent magnets are arranged on the inner stator. It is a double stator type motor arranged so as to face each other,
The permanent magnet is housed and fixed, and is provided with a holder that is inserted and fixed in the through hole. The holder contacts the rotor body when inserted into the through hole and fixed in the insertion direction of the holder. A double stator type motor characterized in that a restricting portion for restricting movement of the motor is provided.   The said restricting part has a 1st restricting part which contacts the side surface by the side of the said inner stator in the said rotor main body, and a 2nd restricting part which contacts the side surface by the side of the outer stator in the said rotor main body. Double stator type motor.   At least one of the first restricting portion or the second restricting portion has elasticity, and the holder is inserted into the through-hole while elastically deforming the one restricting portion, and is in the rotational radius direction of the rotor body. The double stator motor according to claim 2, wherein the one restricting portion contacts a surface different from an insertion direction in which the holder is inserted.   At least one of the first restricting portion or the second restricting portion has flexibility, and by bending the one restricting portion, the rotor body has a rotational radius direction that is different from the direction in which the holder is inserted. The double stator motor according to claim 2, wherein the one restricting portion is in contact.   The first restriction portion has a planar shape, the holder is inserted into the through hole from the inner stator side, and the first restriction portion is locked to a side surface of the rotor body on the inner stator side. Item 5. A double stator motor according to item 1, 2, 3, or 4.   6. The double stator motor according to claim 1, wherein the permanent magnet is fixed to a holder with an adhesive.   6. The double stator motor according to claim 1, wherein the holder is fixed to an inner wall surface of the through hole with an adhesive.   The double stator type motor according to claim 1, 2, 3, 4, 5, 6 or 7, wherein the holder is press-formed from a single metal plate.

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