JP2014121175A - Electric motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electric motor in which breakage of a stator core can be suppressed at the time of injection molding.SOLUTION: An electric motor includes an annular stator whose outline is molded with mold resin and rotors oppositely arranged on magnetic pole surfaces MF of the stator and rotating. The stator includes a stator core 7 formed with compression-molding of magnetic powder. The stator core 7 includes a rod-like winding body part 7A around which a wire is wound, and a flange 7B protruding from an end of the winding body part in a vertical direction. The magnetic pole surfaces MF facing the rotors are formed on the end of the winding body part 7A and the flange 7B, and out of the magnetic pole surfaces MF, the magnetic pole surface on the winding body part side is formed so as to be closer to the rotor than the magnetic pole surface on the flange side.

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 provided with a rotating shaft and that is disposed opposite to the stator and rotates, and the stator compresses and forms magnetic powder. The stator core has a rod-shaped winding drum portion around which the winding is wound, and a flange portion protruding in the vertical direction from an end portion of the winding drum portion. A magnetic pole surface facing the rotor is formed at the end of the body portion and the flange portion, and the magnetic pole surface on the winding body portion side of the same magnetic pole surface is made to be closer to the rotor than the magnetic pole surface on the flange portion side. It is the electric motor characterized by forming so that it may approach.

  The invention according to claim 2 is the electric motor according to claim 1, wherein the magnetic pole surface on the flange side is inclined with respect to the magnetic pole surface on the winding body portion side.

  The invention according to claim 3 is characterized in that the stator is formed by annularly arranging a plurality of electromagnets each having the stator core and the windings. It is an electric motor given in the paragraph.

  According to the first aspect of the present invention, the magnetic pole surface excluding the formation region of the flange portion protrudes toward the opposed rotor so that the force applied from the mold for molding to the magnetic pole surface is increased. Since it can receive at both end surfaces of a winding drum part, it can prevent that a stator core is damaged by applying force to a collar part.

  According to the second aspect of the present invention, since the magnetic pole surface of the flange portion is inclined with respect to the protruding magnetic pole surface, the cogging torque accompanying the rotation of the rotor can be reduced.

  According to the invention described in claim 3, since the stator is composed of a plurality of electromagnets each including the stator core, the winding and the insulator, each force applied to the electromagnet during mold clamping is changed. The force applied to the stator core by being dispersed in the electromagnet can be relaxed.

It is an external view of the electric motor shown as embodiment of this invention. It is a disassembled perspective view except the rotating shaft of the electric motor same as the above. It is a principal part cross-sectional perspective view except the rotating shaft of the electric motor same as the above. The 1st Example of the electromagnet used for the stator of an electric motor same as the above is shown, (a) is the perspective view of the electromagnet, (b) is sectional drawing along the AA line of (a), (c) is (a) It is sectional drawing along the BB line | wire of). It is a perspective view of the stator core single-piece | unit in the electromagnet of 1st Example same as the above. It is explanatory drawing which shows schematically the process of forming the stator using the electromagnet of 1st Example in order from (a)-(d). The 2nd Example of the electromagnet used for the stator of an electric motor same as the above is shown, (a) is the perspective view of the electromagnet, (b) is sectional drawing along CC line of (a), (c) is (a) It is sectional drawing along the DD line | wire of). It is a perspective view of the stator core single-piece | unit in the electromagnet of 2nd Example same as the above. The structure of the electromagnet in the stator of the conventional electric motor is shown, (a) is a perspective view of the electromagnet, (b) is a sectional view along the II line of (a), (c) is a J- It is sectional drawing along a J line. It is a perspective view of the stator core single-piece | unit in the electromagnet of the conventional motor.

  Hereinafter, modes for carrying out the present invention (hereinafter referred to as “embodiments”) will be described with reference to the drawings.

  1 to 3 show an electric motor 1 to which the present invention is applied. Here, an axial gap type electric motor will be described as an example.

  As shown in FIGS. 1 and 3, the electric motor 1 has a configuration in which a stator 3 is sandwiched between two rotors 2A and 2B. The stator 3 is formed by arranging a plurality of electromagnets 4 in an annular shape. (See FIG. 2). That is, the plurality of electromagnets 4 are annularly arranged in a mold for molding, and in this state, the mold resin 12 is injected and cured between the plurality of electromagnets 4, and the outer shell 14 is formed by the mold resin 12. And integrated as a ring-shaped stator 3. 1 to 3 show a state in which the mold resin 12, that is, the outer shell 14, is omitted.

  As shown in FIGS. 1 and 2, the two rotors 2 </ b> A and 2 </ b> B are each formed of a steel plate in a disk shape, and are opposed to each other by providing a slight gap (axial gap) on the magnetic pole surface MF provided on both surfaces of the stator 3. Be placed. One rotary shaft 5 is penetrated and coupled to the center of each rotor 2A, 2B, and these rotors 2A, 2B and the rotary shaft 5 rotate together. In FIGS. 2 and 3, the rotating shaft 5 is omitted. In addition, at the peripheral portions of the rotors 2A and 2B, even-numbered permanent magnets 6 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 3. Is arranged. For example, a bonded magnet is used as the permanent magnet 6.

(First embodiment of electromagnet 4)
FIG. 4 shows a first embodiment of the electromagnet 4 constituting the stator 3 of the electric motor 1 shown in FIGS. The electromagnet 4 according to the first embodiment includes a stator core 7 and windings (copper wires) 9 wound around a winding body portion 7A of the stator core 7 with an insulating insulator 8 interposed therebetween.

  The stator core 7 is formed by compression-molding magnetic powder. As shown in FIG. 5, the winding body 7A and both ends of the winding body 7A in the direction of the rotation axis 5 are connected to the circumferential direction of the stator 3 from the both ends. A pair of flanges 7B, 7B formed so as to project outward and extend in the right-angle direction (horizontal direction) are formed integrally with each other to form a bobbin, and a winding 9 wound around the winding body 7A is formed. It fits between a pair of collar parts 7B and 7B. Further, the stator core 7 has a magnetic pole surface MF at positions facing the permanent magnets 6 of the rotors 2A and 2B, that is, both end surfaces in the rotation axis direction, and the flange portions 7B and 7B expand the area of the magnetic pole surface MF. Protruding. This magnetic pole surface MF is composed of first magnetic pole surfaces 7A1 and 7A2 constituted by the end surface of the stator core 7 on the winding body portion 7A side, and second magnetic pole surfaces 7B1 and 7B2 constituted by the end surface of the stator core 7 on the flange portion 7B side. Composed. Here, the first magnetic pole surfaces 7A1 and 7A2 are formed so as to be closer to the rotors 2A and 2B than the second magnetic pole surfaces 7B1 and 7B2. That is, the first magnetic pole surfaces 7A1 and 7A2 are formed to protrude toward the rotors 2A and 2B rather than the second magnetic pole surfaces 7B1 and 7B2. Accordingly, when the electromagnet 4 is placed in a mold for molding described later and fixed by the upper and lower molds, the force applied to the electromagnet 4 from the mold is received by the first magnetic pole surfaces 7A1 and 7A2, and therefore the second No force is applied to the magnetic pole surfaces 7B1 and 7B2 (the flange portions 7B and 7B).

  Each of the first magnetic pole surfaces 7A1 and 7A2 is located inside the regions S and S (see FIG. 5) forming the flange portions 7B and 7B, that is, between the pair of flange portions 7B and 7B shown in FIG. ) It is formed inside L1. In the first embodiment, the first magnetic pole surfaces 7A1 and 7A2 are formed in a region (location) L2 provided in the central portion of the region L1. A region from both ends of the region L2 to the tip of the flange portion 7B, that is, the second magnetic pole surfaces 7B1 and 7B2 are inclined to form a taper T so that the first magnetic pole surfaces 7A1 and 7A2 become the second magnetic pole surface 7B1. , 7B2 so as to protrude toward the rotor. The present invention is not limited to this embodiment, and the first magnetic pole surfaces 7A1 and 7A2 may be formed in the same region as the region L1.

  And the electromagnet 31 shown as 1st Example is formed by winding the coil | winding 9 through the insulator 8 in the winding trunk | drum part 7A of each stator core 7, as shown in FIG. The insulator 8 may be injection-molded so as to be integrated with the winding body portion 7A of the stator core 7, or the insulator 8 may be formed separately in advance and attached to the winding body portion 7A. . The insulator 8 is provided so as to cover the outer peripheral surface of the winding body portion 7A and the outer peripheral surfaces of the flange portions 7B and 7B excluding the magnetic pole surface MF.

  Moreover, the stator 3 of the electric motor 1 using the electromagnet 4 of the first embodiment is manufactured through the steps shown in FIGS. 6A to 6D, for example. First, the stator core 7 is formed of a dust core (a). Next, the insulator 8 is attached to the winding body 7A of the stator core 7 (b), and the winding 9 is wound around the winding body 7A from the outside of the insulator 8 to form the electromagnet 4 (c).

  Next, a plurality of electromagnets 4 are annularly arranged in a mold for molding of an injection molding machine and fixed between the upper and lower molds 11A and 11B (d). In this fixed state, the flange portion 7B is provided with a taper T, so that the magnetic pole surface MF other than the first magnetic pole surface 7A1, 7A2 portion, that is, the second magnetic pole surface 7B1, 7B2 and the molds 11A and 11B are formed with a gap (gap δ1 at the tip of the flange part 7B) that extends toward the tip of the flange part 7B. The molds 11A and 11B are applied only to the first magnetic pole surfaces 7A1 and 7A2. Touch.

  Thereafter, as shown in FIG. 6 (d), the mold resin 12 is injected between the molds 11A and 11B, and the gap between the winding 9 and the electromagnets 4 and 4 is filled with the injected mold resin 12, The gap δ1 is filled. When the mold resin 12 is cured, the plurality of electromagnets 4 are integrated. When the mold resin 11 is removed from the molds 11A and 11B, the stator 3 having the mold resin 12 as the outer shell 14 is formed.

  According to the electric motor 1 using the electromagnet 4 of the first embodiment described above, the first magnetic pole surface 7A1 formed so as to protrude from the second magnetic pole surfaces 7B1 and 7B2 toward the opposed rotor. Since 7A2 is provided on the magnetic pole surface MF, when the electromagnet 4 is placed between the upper and lower molds 11A and 11B of the injection molding machine and clamped, the clamping force P is received by the first magnetic pole surfaces 7A1 and 7A2. be able to. Therefore, the clamping force is not applied to the magnetic pole surface MF other than the portion where the first magnetic pole surfaces 7A1 and 7A2 are provided, that is, the second magnetic pole surfaces 7B1 and 7B2 provided with the flange portion 7B having poor strength. It can prevent that the collar part 7B is damaged.

  Furthermore, since the second magnetic pole surfaces 7B1 and 7B2 are covered with the mold resin 12 when the stator 3 is molded, for example, when the electric motor 1 is assembled, the stator 3 comes into contact with an assembly jig (not shown). Thus, it is possible to more effectively prevent the flange portion 7B of the stator 3 from being damaged. Further, even when the magnetic pole surface MF and the flange portion 7B are damaged, the broken pieces can be prevented from falling by the mold resin 12 covering the magnetic pole surface MF, so that the damaged pieces are applied to the permanent magnets 6 of the rotors 2A and 2B. It can be prevented from being adsorbed.

  Furthermore, since the stator core 7 is configured by arranging a plurality of electromagnets 4 in an annular shape, the first magnetic pole surfaces 7A1 and 7A2 can be provided for each electromagnet 4. Therefore, when the mold of the injection molding machine is clamped, The force applied from the molds 11 </ b> A and 11 </ b> B can be dispersed in each electromagnet 4 to reduce the force applied to each electromagnet 4.

Furthermore, the region (first magnetic pole surface 7A1, 7A2) of the magnetic pole surface MF of the stator core 7 projects toward the rotors 2A, 2B, while the region from the central portion to the tip of the flange portion 7B, that is, the second magnetic pole. The surfaces 7B1 and 7B2 are inclined. Therefore, the distance between the permanent magnet 6 and the magnetic pole surface MF decreases in the central region of the magnetic pole surface MF, and gradually increases toward the tip of the flange portion 7B. For this reason, the cogging torque accompanying rotation of rotor 2A, 2B can be made small.

(Second embodiment of electromagnet 4)
7 shows a second embodiment of the electromagnet 4 constituting the stator 3 of the electric motor 1 shown in FIGS. 1 to 3, and FIG. 8 is a perspective view of the stator core 72 alone in the electromagnet 4 of FIG. In the electromagnet 4 shown in the second embodiment, the first magnetic pole surfaces 7A1 and 7A2 provided on the magnetic pole surface MF of the stator core 72 are arranged inside the regions S and S (see FIG. 8) forming the flange portions 7B and 7B, That is, it is formed inside the region (location) L1 between the pair of flange portions 7B and 7B shown in FIG. In the second embodiment, the region from the boundary with the portion of the region (location) L2 provided at the center of the region L1 to the tip of the flange portion 7B is lowered inward by the dimension δ2 from the portion of the region L2, The portion L2 (the first magnetic pole surfaces 7A1 and 7A2) is formed by providing a step 13 so as to protrude from the magnetic pole surface MF toward the rotors 2A and 2B, and the other configurations are the same as in the first embodiment. Therefore, the same parts are denoted by the same reference numerals, and redundant description is omitted.

  And when manufacturing the stator 3 of the electric motor 1 using the electromagnet 4 of 2nd Example, first, similarly to the case of 1st Example, the stator core 72 is formed with a powder iron core, and then the stator core 72 An insulator 8 is attached to the winding drum portion 7A, the winding 9 is wound around the winding drum portion 7A from the outside of the insulator 8, and the electromagnet 4 is manufactured. A plurality of the electromagnets 4 are prepared. FIG. 7A shows one electromagnet 4 manufactured in this way.

  Next, a plurality of electromagnets 4 are annularly arranged in a mold for molding of an injection molding machine, and are fixed between upper and lower molds 11A and 11B as shown in FIGS. 7 (b) and 7 (c). In this fixed state, the molds 11A and 11B are in contact with the first magnetic pole surfaces 7A1 and 7A2 protruding from the magnetic pole surface MF, and other magnetic pole surfaces MF excluding the first magnetic pole surfaces 7A1 and 7A2, that is, the second magnetic pole surfaces. A gap δ2 due to the step 13 is formed between the surfaces 7B1 and 7B2 and the molds 11A and 11B as shown in FIG.

  Thereafter, as in the case of the first embodiment, a mold resin is injected between the molds 11A and 11B, and the gap between the winding 9 and each electromagnet 4 is filled with the injected mold resin, and at the same time, the gap δ2 is set. fill in. When the mold resin is cured, the plurality of electromagnets 4 are integrated, and when the mold is removed from the molds 11A and 11B, the stator 3 is formed with the mold resin as an outer shell.

  According to the electric motor 1 using the electromagnet 4 of the second embodiment described above, the first magnetic pole surfaces 7A1 and 7A2 are formed so as to protrude toward the rotors 2A and 2B. In addition, when the electromagnet 4 is fixed between the upper and lower molds 11A and 11B of the injection molding machine, the force applied to the electromagnet 4 at the time of clamping can be received by the first magnetic pole surfaces 7A1 and 7A2. Accordingly, no force is applied to the magnetic pole surfaces MF other than the first magnetic pole surfaces 7A1 and 7A2, that is, the second magnetic pole surfaces 7B1 and 7B2 provided with the flange portions 7B having a low strength other than the region L2, and the flange portion 7B is damaged. Can be prevented.

  In each of the above-described embodiments, 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 is used. Even if it exists, this invention is applicable.

DESCRIPTION OF SYMBOLS 1 Electric motor 2A, 2B Rotor 3 Stator 4 Electromagnet 5 Rotating shaft 6 Permanent magnet 7, 72, 73, 74 Stator core 7A Winding trunk | drum 7A1, 7A2 1st magnetic pole surface 7B1, 7B2 2nd magnetic pole surface 7B Hook 8 Insulator 9 Winding 11A, 11B Upper and lower molds 12 Mold resin 13 Steps δ1, δ2 Clearance P Mold clamping force

Claims (3)

An outer stator molded with a mold resin, an annular stator, and a rotor provided with a rotation shaft and arranged to face the stator and rotate;
The stator has a stator core formed by compression molding magnetic powder,
The stator core has a rod-shaped winding drum portion around which the winding is wound, and a flange portion protruding in the vertical direction from the end of the winding drum portion,
A magnetic pole surface facing the rotor is formed at an end of the winding drum portion and the flange portion,
Of the same magnetic pole surfaces, the electric pole surface on the winding body portion side is formed so as to be closer to the rotor than the magnetic pole surface on the flange portion side. The electric motor according to claim 1, wherein the magnetic pole surface on the flange side is inclined with respect to the magnetic pole surface on the winding body side. 3. The electric motor according to claim 1, wherein the stator is formed by annularly arranging a plurality of electromagnets each having the stator core and the windings. 4.

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