JP6003587B2 - Electric motor - Google Patents

Description

  The present invention relates to an electric motor.

  A stator core constituting a stator of an electric motor has a winding drum portion provided with a flange portion, and the winding is generally wound around the winding drum portion with an insulating insulator interposed. By the way, in the conventional electric motor, there is one in which the stator core is formed of a compacted iron core formed by compression molding of magnetic powder, and the insulator is formed so as to be integrated with the winding drum portion by resin injection molding (for example, Patent Document 1).

  In this case, since the insulator is disposed so as to cover from the outer periphery of the winding body portion to the inner side surface of the flange portion, the injection pressure of the resin is applied to the flange portion during the molding of the insulator. For this reason, in order to prevent that a collar part is damaged by injection pressure, the outer surface of a collar part is pressed with a metal mold | die with the pressure more than equivalent to an injection pressure.

JP 2008-278684 A

  However, if the outer surface of the collar is pressed with a mold before the resin is injected, the collar may be damaged by the force applied to the magnetic pole surface from the mold.

  This invention is made | formed in view of this point, and it aims at providing the electric motor which can suppress the failure | damage of a stator core at the time of injection molding.

  The invention described in claim 1 includes an annular stator whose outer shell is molded with a mold resin, and a rotor that is disposed opposite to the magnetic pole surface of the stator and rotates, and the stator compresses magnetic powder. A stator core formed with the magnetic pole surface, a winding wound around the winding core portion of the stator core with an insulating insulator interposed therebetween, and provided on the winding drum portion to increase the area of the magnetic pole surface. And a columnar member projecting from the magnetic pole surface toward the rotor is provided on the magnetic pole surface excluding the formation region of the flange portion of the stator core. It is an electric motor.

  The invention according to claim 2 is the electric motor according to claim 1, wherein the columnar member is provided on a fixing member formed on the stator core.

  A third aspect of the present invention is the electric motor according to the second aspect, wherein the fixing member is formed integrally with the insulator.

  The invention according to claim 4 is the electric motor according to claim 2, wherein the fixing member is formed separately from the insulator and is formed in an annular shape along the stator.

  The invention according to claim 5 is the electric motor according to any one of claims 2 to 4, wherein the fixing member is disposed in non-contact with the magnetic pole surface.

  The invention according to claim 6 is the electric motor according to any one of claims 1 to 5, wherein the magnetic pole surface is covered with the mold resin.

  A seventh aspect of the present invention is the electric motor according to any one of the first to sixth aspects, wherein the stator core is composed of a plurality of divided cores.

  According to the first aspect of the present invention, the rotor is formed on the magnetic pole surface of the stator core from the magnetic pole surface on the magnetic pole surface excluding the formation region of the flange portion protruding so as to increase the area of the magnetic pole surface. Since the columnar member projecting toward is provided, the force applied to the magnetic pole surface from the mold for molding can be relaxed, and it is possible to avoid the force from the mold being applied to the brim portion having poor strength. The stator core can be prevented from being damaged.

  According to the second aspect of the present invention, since the columnar member is provided on the fixing member formed on the stator core, it is possible to prevent the columnar member from being displaced from a predetermined position during molding resin molding.

  According to the third aspect of the present invention, since the fixing member is formed integrally with the insulator, the positioning structure can be simplified without disturbing the magnetic flux of the magnetic pole surface, and the increase in the number of parts can be suppressed. Can be reduced.

  According to the fourth aspect of the present invention, since the fixing member is formed separately from the insulator, the forming mold structure of the insulator can be simplified. Further, since the fixing member is formed in an annular shape along the stator, the fixing member can be positioned more reliably in the entire stator.

  According to the fifth aspect of the present invention, since the fixing member can be arranged in non-contact with the magnetic pole surface, it is possible to avoid applying force from the fixing member to the magnetic pole surface and the flange portion.

  According to the sixth aspect of the present invention, since the magnetic pole surface is covered with the mold resin, it is possible to easily suppress the damage to the magnetic pole surface and the flange portion, and even when the magnetic pole surface is damaged, the broken piece falls and is attracted to the roller. Can be prevented.

  According to the seventh aspect of the present invention, since the stator core is composed of a plurality of divided cores, a columnar member can be provided in each divided core, and the force applied to the stator core from the mold is distributed to each divided core. Can be relaxed.

It is an external view of the electric motor in an embodiment. It is a disassembled perspective view except the rotating shaft of the electric motor. It is a principal part cross-sectional perspective view except the rotating shaft of the electric motor. It is a perspective view of a split core. It is a perspective view of the electromagnet which wound the coil | winding to the division | segmentation core. It is explanatory drawing which shows schematically the basic process of forming a stator in order from (a) to (f). It is a perspective view which shows the stator which comprises the electric motor of 1st Embodiment taking the example to one division | segmentation core. FIG. 8 is a cross-sectional view taken along the line II in FIG. It is explanatory drawing which shows schematically the process of forming the stator of 1st Embodiment later on to (a)-(f). It is a disassembled perspective view which shows the stator which comprises the electric motor of 2nd Embodiment taking the example to one division | segmentation core. It is sectional drawing of the assembly | attachment state along the II-II line | wire in FIG. It is a principal part expanded sectional view of the fixing member along the III-III line in FIG. It is a principal part expanded sectional view corresponding to FIG. 12 which shows the modification of a fixing member.

(First embodiment)
Hereinafter, a first embodiment of the present invention will be described with reference to the drawings. 1 to 3 show an electric motor 1 to which the present invention is applied. In particular, this embodiment will be described taking an axial gap type electric motor 1 as an example.

  As shown in FIGS. 1 and 3, the electric motor 1 has a structure in which a stator 3 is sandwiched between two rotors 2 and 2A. The stator 3 is formed by arranging a plurality of electromagnets 31 in an annular shape. (See FIG. 2). The plurality of electromagnets 31 arranged in an annular shape as described above are molded with a molding resin 6 described later, thereby forming an outer shell 7 (see FIG. 6). 1 to 3 show the state in which the mold resin 6 is omitted.

  As shown in FIGS. 1 and 2, the two rotors 2, 2 </ b> A are each formed of a steel plate in a disc shape, and are arranged to face each other with a slight gap (gap) from the magnetic pole surface MF provided on both surfaces of the stator 2. Is done. A single rotating shaft 4 is penetrated and coupled to the center of each rotor 2, 2 </ b> A, and the rotors 2, 2 </ b> A and the rotating shaft 4 rotate together. In FIGS. 2 and 3, the rotating shaft 4 is omitted. Further, at the peripheral portions of the rotors 2 and 2A, even-numbered permanent magnets 21 are equally spaced in the circumferential direction so that N poles and S poles are alternately arranged at positions corresponding to the magnetic pole surface MF of the stator 2. Is arranged. For example, a bonded magnet is used for the permanent magnet 21.

  As shown in FIG. 3, the stator 3 includes a stator core 32 and windings (copper copper) wound around a winding body 32 a of the stator core 32 with a non-conductive and non-magnetic insulator 33 interposed therebetween. Line) 34. The stator core 32 includes a plurality of divided cores 32D (see FIG. 4), and each divided core 32D is arranged in an annular shape. Each divided core 32D is formed of a compacted iron core obtained by compression-molding magnetic powder.

  Each of the split cores 32D is provided with a winding drum portion 32a, and a pair of flange portions 32b are formed at both ends in the direction of the rotation axis 4 of the winding drum portion 32a, and the winding wound around the winding drum portion 32a. 34 fits between the pair of flanges 32b.

  And as shown in FIG. 3, the electromagnet 31 is formed by winding the coil | winding 34 by interposing the insulator 33 in the winding trunk | drum 32a of each division | segmentation core 32D. In the electromagnet 31, both end surfaces 32a1 and 32a2 of the winding body portion 32a in the direction of the rotation axis 4 are magnetic pole surfaces MF. The flange 32b protrudes in the circumferential direction so as to widen the end surfaces 32a1 and 32a2 (magnetic pole surface MF), and the area of the magnetic pole surface MF is enlarged by both end surfaces 32b1 and 32b2 of the flange 32b in the rotation axis 4 direction. The The insulator 33 may be injection-molded so as to be integrated with the winding drum portion 32a of the split core 32D. Alternatively, the insulator 33 may be formed separately and retrofitted to the winding drum portion 32a. Good.

  Conventionally, the stator 3 of the electric motor 1 having such a configuration is manufactured through the steps shown in FIGS. That is, first, the split core 32D constituting the stator core 32 is formed of a dust core (a), then the insulator 33 is attached to the winding body 32a of the split core 32D (b), and the winding 34 is further formed. Is wound to form the electromagnet 31 (c).

  Next, after arranging a plurality of electromagnets 31 in a space formed between the upper and lower molds 5 and 5A of the injection molding machine for molding, the upper and lower molds 5 and 5A are closed (clamping). (D), and in this fixed state, mold resin 6 is injected into the space formed between the molds 5 and 5A from the side (inner and outer peripheral sides of the stator 3) (e).

  In the steps (d) and (e), a clamping force P1 is applied to the molds 5 and 5A so that the molds 5 and 5A do not open with respect to the injection pressure of the mold resin 6. Then, when the electromagnet 31 is removed from the molds 5 and 5A after the mold resin 6 is cured, the stator 3 in which the cured mold resin 6 becomes the outer shell 7 is formed (f).

  In the manufacturing method shown in FIG. 6, since force is applied to the entire magnetic pole surface MF of the split core 32D from the molds 5 and 5A at the time of mold clamping, as shown in the steps (d) to (f), Cracks C are likely to enter the base of the flange 32b of the core 32D.

  For this reason, in this embodiment, as shown in FIGS. 7 and 8, relaxation is a columnar member projecting from the magnetic pole surface MF toward the rotor 2 on the magnetic pole surface MF of the split core 32 </ b> D (stator core 32). Part 10 is provided. The relaxation portion 10 relaxes the force applied to the magnetic pole surface MF of the split core 32D from the molds 5 and 5A. That is, as shown in FIG. 8, the relaxing portion 10 has the fixing member 11 on the end surfaces 32 a 1 and 32 a 2 of the winding body portion 32 a (on the magnetic pole surface MF excluding the formation region A (end surfaces 32 b 1 and 32 b 2) of the flange portion 32 b). Is fixed on the end faces 32a1 and 32a2. The end surfaces 32a1 and 32a2 are high strength portions.

  The fixing member 11 is formed of the same insulating material as the insulator 33 by being integrally formed so as to cover a part of the magnetic pole surface MF from both ends 33a of the insulator 33 attached to the winding body portion 32a. And the relaxation part 10 protrudes the prism-shaped member which has the predetermined | prescribed height h by integral molding on the outer surface 11a used as the opposite side to the magnetic pole surface MF of the fixing member 11. FIG. Accordingly, the relaxing portion 10 is also formed of the same insulating material as the insulator 33. In addition, although the relief | moderation part 10 protrudes in prismatic shape, the shape does not need to be limited to it, What is necessary is just the column shape which protruded toward the rotor 2 at least from the magnetic pole surface MF. Moreover, it is preferable that the relaxation part 10 is arrange | positioned in the approximate center part of the end surfaces 32a1 and 32a2.

  The stator 3 of the present embodiment provided with the relaxing portion 10 is manufactured through the steps shown in FIGS. First, similarly to FIG. 6A, the split core 32D constituting the stator core 32 is formed of a dust core (a). Next, as in FIG. 6B, the insulator 33 is attached to the winding body portion 32 a of the split core 32 </ b> D. At the same time as the insulator 33 is attached, the fixing member 11 and the relaxation portion integrated with the insulator 33. 10 is installed (b). Then, similarly to FIG. 6C, the winding 34 is wound with the insulator 33 interposed in the winding body portion 32a, and the electromagnet 31 provided with the relaxing portion 10 is formed (c).

  Next, similarly to FIG. 6D, a plurality of electromagnets 31 are arranged in an annular shape and fixed between the upper and lower molds 5 and 5A of the injection molding machine for molding (d). In this fixed state, the molds 5 and 5A come into contact with the relaxing portion 10 protruding from the fixing member 11, and between the molds 5 and 5A and the magnetic pole surface MF, and between the molds 5 and 5A and the fixing member 11. Gaps δ1 and δ2 are formed between the outer surface 11a and the outer surface 11a.

  Next, as in FIG. 6E, the mold resin 6 is injected between the molds 5 and 5A from the inner and outer peripheral sides of the stator 3 (e). The injected mold resin 6 fills the winding 34 and at the same time enters the gaps δ 1 and δ 2, between the molds 5, 5 A and the magnetic pole surface MF, and between the molds 5, 5 A and the outer surface 11 a of the fixing member 11. Fill the gap between. Of course, in the steps (d) and (e), the mold clamping force P1 that opposes the injection pressure is applied to the molds 5 and 5A.

  Then, similarly to FIG. 6 (f), after the mold resin 6 is cured, the stator 3 is removed from the molds 5, 5A (f). In the removed stator 3, the hardened mold resin 6 becomes the outer shell 7, but the magnetic pole surface MF is covered with the mold resin 6 that has entered the gaps δ1 and δ2. At this time, the fixing member 11 and the relaxing portion 10 are embedded in the mold resin 6 covering the magnetic pole surface MF.

  According to the electric motor 1 of the first embodiment described above, since the relaxation portion 10 is arranged on the magnetic pole surface MF, the electromagnet 31 is arranged between the upper and lower molds 5 and 5A of the injection molding machine and clamped. When the force P1 is applied, the force applied to the magnetic pole surface MF of the split core 32D can be intensively input to the relaxation unit 10. The relaxing portion 10 is provided on the magnetic pole surface MF excluding the formation region A of the flange portion 32b of the split core 32D (stator core 32), that is, on the end surfaces 32a1 and 32a2 having high strength. Therefore, it can relieve | moderate that force is added to the collar part 32b with few intensity | strengths, and it can suppress that the collar part 32b is damaged.

  Moreover, since the relaxation part 10 is being fixed to the split core 32D side by the fixing member 11 extended integrally from the insulator 33, when the mold clamping force P1 is applied to the metal molds 5 and 5A, and the mold resin 6 It is possible to prevent the relaxing portion 10 from being displaced when the injection pressure is applied. At this time, since the fixing member 11 is formed integrally with the insulator 33, the fixing structure can be simplified without interfering with the magnetic flux of the magnetic pole surface MF, and the number of parts can be reduced by suppressing an increase in the number of parts.

  Furthermore, when the stator 3 is molded, the magnetic pole surface MF is covered with the mold resin 6, so that even when an external force is applied to the stator 3, the magnetic pole surface MF and the flange 32 b are damaged during motor assembly. It can suppress more effectively. In the unlikely event that the magnetic pole surface MF or the flange 32b is damaged, the broken pieces can be prevented from falling off the stator 3 with the mold resin 6 covering the magnetic pole surface MF. Can be prevented from being attracted to the permanent magnet 21.

  Furthermore, by providing the relaxation portion 10 for each of the plurality of divided cores 32D, the force applied to the stator core 32 from the molds 5 and 5A can be distributed to the divided cores 32D and relaxed.

(Second Embodiment)
10 to 12 show a second embodiment of the present invention, in which the same components as those in the first embodiment are denoted by the same reference numerals, and redundant description is omitted. This embodiment is different from the first embodiment in that the fixing member 11A is formed separately from the insulator 33 and is formed annularly along the stator 3.

  As shown in FIG. 10, the fixing member 11A is formed in an annular shape with a width B smaller than the radial dimension L of the magnetic pole surface MF. Then, as shown in FIG. 12, the relaxing portion 10 protrudes from the outer side surface 11Aa of the fixing member 11A into a prismatic shape with a predetermined height h ′ by integral molding. Of course, even in this case, the relaxing portion 10 need not be limited to a prismatic shape.

  The fixing member 11 </ b> A is formed separately from the insulator 33, but is formed of the same insulating material as that of the insulator 33, whereby the relaxing portion 10 is also formed of the same insulating material as that of the insulator 33. . The fixing member 11A only needs to be formed of an insulating material, and is not necessarily formed of the same material as the insulator 33.

  Then, the fixing member 11A is disposed so as to contact the magnetic pole surface MF, as shown in FIG. At this time, the pair of positioning holes 11Ab formed on both sides in the circumferential direction of the relaxing portion 10 of the fixing member 11A are fitted to a pair of positioning protrusions 33P that are integrally projected from both ends 33a across the magnetic pole surface MF of the insulator 33. It is. Thereby, the fixing member 11A can be positioned and fixed to the split core 32D. Also in the present embodiment, the relaxing portion 10 is fixed on the end faces 32a1 and 32a2.

  According to the electric motor 1 of 2nd Embodiment demonstrated above, since the relaxation part 10 is arrange | positioned on end surface 32a1, 32a2, there can exist an effect similar to 1st Embodiment. Moreover, according to this embodiment, since the fixing member 11A is formed separately from the insulator 33, the structure of the insulator 33 can be simplified. Further, since the fixing member 11A is formed in an annular shape along the stator 3, the fixing member 11A can fix the relaxing portion 10 on the end surfaces 32a1 and 32a2 and connect the split core 32D in an annular shape.

  FIG. 13 shows a modification of the second embodiment, in which the relaxing portions 10 are provided on both surfaces of the fixing member 11A, that is, both the outer surface 11Aa and the inner surface 11Ab opposite to the magnetic pole surface MF. is there. Even in this modification, the fixing member 11A is formed of an insulating material, and the relief portions 10 on both sides are formed by integral molding with the fixing member 11A.

  Therefore, according to the present modification, the fixing member 11A can be disposed in non-contact with the magnetic pole surface MF, so that it is possible to avoid applying a force from the fixing member 11A to the magnetic pole surface MF (particularly the flange portion 32b). In addition, although the case where the relaxation part 10 was provided in both surfaces of 11 A of fixed members was described in this modification, the relaxation part 10 should just be provided in inner surface 11Ab at least. Moreover, the structure which provides the relaxation part 10 of this modification in at least inner surface 11Ab of 11 A of fixing members is applicable also to the fixing member 11 of 1st Embodiment.

  By the way, in each of the embodiments described above, the axial gap type electric motor 1 has been described as an example. However, the present invention is not limited to this, and for example, a radial gap type electric motor in which the gap between the rotor and the stator is in the radial direction. The present invention can also be applied to an electric motor. Moreover, although the relaxation part 10 described the case where it formed integrally with the fixing members 11 and 11A, the relaxation part 10 was formed separately from the fixing members 11 and 11A, and the separate relaxation part 10 was fixed by bonding or the like. It can also be provided integrally with the members 11 and 11A.

DESCRIPTION OF SYMBOLS 1 Electric motor 2, 2A Rotor 3 Stator 32 Stator core 32a Winding drum part 32b Eaves part 32D Divided core 33 Insulator 34 Winding 5, 5A Mold 6 Mold resin 7 Outer 10 Relaxation part 11, 11A Fixing member 11Ab Inner side surface (pole surface Opposite side)
MF magnetic pole surface A ridge formation area

Claims (7)

An outer stator whose outer shell is molded with a mold resin, and a rotor that is disposed opposite to the magnetic pole surface of the stator and rotates,
The stator includes a stator core formed by compression molding magnetic powder and provided with the magnetic pole surface, a winding wound around a winding drum portion of the stator core with an insulating insulator interposed therebetween, and Provided, and has a flange that protrudes to increase the area of the magnetic pole surface,
An electric motor comprising a columnar member projecting from the magnetic pole surface toward the rotor on the magnetic pole surface excluding a region where the flange portion of the stator core is formed.   The electric motor according to claim 1, wherein the columnar member is provided on a fixing member formed on the stator core.   The electric motor according to claim 2, wherein the fixing member is formed integrally with the insulator.   The electric motor according to claim 2, wherein the fixing member is formed separately from the insulator and is formed in an annular shape along the stator.   The electric motor according to any one of claims 2 to 4, wherein the fixing member is disposed in non-contact with the magnetic pole surface.   The electric motor according to claim 1, wherein the magnetic pole surface is covered with the mold resin.   The electric motor according to claim 1, wherein the stator core includes a plurality of divided cores.

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