JP2020074664A - Manufacturing method of stator - Google Patents

Abstract

To provide a stator which is adaptable to a high torque by suppressing magnetic saturation in a yoke of a stator core while suppressing radial enlargement of the stator core.SOLUTION: The present invention relates to a stator manufacturing method including: a coil molding step of molding a coil 17 by winding a conductor around teeth 13 of a stator core 11; a resin mold step of molding a resin so as to cover an outer surface of a coil end portion; and a magnetic body fitting step of fitting a magnetic body 31 which extends in a circumferential direction, to an annular axial end face of a yoke exposed between the radial outside of the molded resin and an outer periphery of a yoke 12, so as to form a magnetic path between one tooth 13 and the other adjacent tooth 13 after the resin mold step.SELECTED DRAWING: Figure 6

Description

  The present invention relates to a method for manufacturing a stator used in a vehicle drive motor (rotary electric machine).

  2. Description of the Related Art As a driving motor for a hybrid vehicle or an electric vehicle, a permanent magnet type motor in which a rotor is embedded with a permanent magnet so as to obtain a small output torque is used. When the output torque of the permanent magnet type motor is large, the magnetic flux flowing through the stator core also becomes large. Therefore, if the teeth width and the yoke width are set large so that the magnetic flux is not saturated, and the magnetic flux flowing through the teeth and the yoke of the stator core is reduced and the magnetic flux is evenly distributed, the efficiency of the motor increases (for example, Patent Document 1). 1). On the other hand, if magnetic saturation occurs in the stator core, a large torque output will not be produced and the motor efficiency will decrease. For this reason, the stator core is designed to have a thickness and shape so that magnetic saturation does not occur (for example, refer to Patent Document 2).

JP, 9-308198, A JP-A-5-252714

  By the way, in order to realize a motor capable of outputting a high torque, it is necessary to widen the yoke portion of the stator core, which causes a problem that the stator core becomes large in the radial direction.

  Therefore, it is an object of the present invention to provide a stator capable of coping with high torque by suppressing magnetic saturation in the yoke of the stator core while suppressing the radial size increase of the stator core.

  A method of manufacturing a stator according to the present invention is a coil forming method in which a conductor is wound around the teeth of a stator core including an annular yoke and a plurality of teeth protruding inward in a radial direction from an inner peripheral surface of the yoke to form a coil. A step, a resin molding step of molding a resin so as to cover the outer surface of the coil end portion projecting outward in the axial direction from the axial end surface of the tooth with a part of the coil formed in the coil forming step, After the resin molding step, the annular axial end surface of the yoke exposed between the outer side of the molded resin in the radial direction and the outer periphery of the yoke has a magnetic field between one tooth and another adjacent tooth. A magnetic body attaching step of attaching a magnetic body extending in the circumferential direction so as to form a path.

  INDUSTRIAL APPLICABILITY The present invention can provide a stator capable of coping with high torque by suppressing magnetic saturation in the yoke of the stator core while suppressing the radial size increase of the stator core.

It is a perspective view showing the outline of the stator manufactured by the manufacturing method of the stator of an embodiment. It is a perspective view which shows the external shape of the stator core of the stator shown in FIG. It is a perspective view which shows the coil wound around the teeth of the stator shown in FIG. FIG. 3 is a perspective view showing a stator assembly in which coils are wound around each tooth in the stator shown in FIG. 1. FIG. 5 is a perspective view showing a stator in which a coil end of the stator assembly shown in FIG. 4 is resin-molded. It is a perspective view which shows attachment of the magnetic body to the stator shown in FIG. It is the top view which expanded the stator shown in FIG. 1 in the circumferential direction, and its elevation view. It is a perspective view which shows the external shape of the stator manufactured by the manufacturing method of the stator of other embodiment. FIG. 9 is a plan view in which the stator shown in FIG. 8 is expanded in the circumferential direction, and an elevation view thereof.

  Hereinafter, a stator manufactured by the stator manufacturing method of the embodiment will be described with reference to the drawings. The stator 100 includes a stator core 11, a plurality of coils 17 wound around a plurality of teeth 13 of the stator core 11, and a coil end portion 18 that protrudes axially outward from an axial end surface 11a of the stator core 11 of the coil 17 (see FIG. 3). , 4), and a magnetic body 31 disposed on the axial end surface 11a of the stator 100. In the following description, as shown in FIG. 1, the outer circumferential direction of the stator core 11 having an annular outer shape is “circumferential direction”, the radial direction of the stator core 11 is “radial direction”, and the thickness direction of the stator core 11 is “axial direction”. That.

  Next, the structure and manufacturing method of the stator 100 will be described with reference to FIGS. As shown in FIG. 2, the stator core 11 includes an annular yoke 12 and a plurality of teeth 13 protruding inward in the radial direction from the inner peripheral surface of the yoke 12. The stator core 11 may be manufactured by stacking a plurality of electromagnetic steel plates, or may be manufactured by pressure molding magnetic powder. A mounting boss 15 is provided on the outer peripheral surface of the stator core 11. The boss 15 is provided with a hole 16 through which a bolt for fixing the stator 100 to a casing (not shown) is inserted.

  As shown in FIG. 3, a conductor is wound around each tooth 13 of the stator core 11 to form a coil 17. There are several methods for winding the coil 17, but as shown in FIG. 3, an insulating member 20 (bobbin) formed of an insulating material having a rectangular tubular shape and flanges protruding on both end faces in the radial direction is used. There is a method in which the conductor 17 is wound to form the coil 17 and the insulating member 20 and the coil 17 are integrally inserted into the tooth 13. Alternatively, the coil 17 may be formed by inserting a conductor into the slots 14 between the teeth 13 shown in FIG.

  When the conductor 17 is wound around the tooth 13 to form the coil 17, the conductor on the axial end surface 13a of the tooth 13 is axially outer than the axial end surface 13a of the tooth 13 or the axial end surface 11a of the stator core 11. Project to. The coil end portion 18 is a portion of the coil 17 that protrudes outward in the axial direction from the axial end surface 13 a of the tooth 13 or the axial end surface 11 a of the stator core 11. When the coils 17 are formed around all the teeth 13, a stator assembly 90 as shown in FIG. 4 is obtained.

  As shown in FIG. 4, an annular portion 11b where the axial end surface 11a (metal surface) of the stator core 11 is exposed is formed between the outer side of the coil end portion 18 in the radial direction and the outer circumference of the yoke 12.

  Next, when the coil end portion 18 of the stator assembly 90 shown in FIG. 4 is covered with a mold for resin molding, resin is injected into the mold, and the coil end portion 18 and the insulating member 20 are molded with resin, As shown in FIG. 5, a donut-shaped resin mold 21 is formed on the axial end surface 11 a of the stator core 11. Between the resin mold 21 and the outer periphery of the yoke 12, an annular portion 11b where the axial end surface 11a (metal surface) of the stator core 11 is exposed remains.

  Next, as shown in FIG. 6, a magnetic body 31 extending in the circumferential direction is attached onto the annular portion 11b so as to form a magnetic path between the teeth 13. The magnetic body 31 may be formed, for example, by stacking electromagnetic steel sheets, or may be formed by press-molding magnetic powder. The magnetic body 31 has an arc shape, an inner diameter that is the same as or slightly larger than the outer diameter of the resin mold 21, the outer diameter is smaller than the outer diameter dimension of the yoke 12, and a size that can be installed on the annular portion 11b. It has become. In the embodiment shown in FIG. 6, the circumferential length of the magnetic body 31 is slightly shorter than the distance between the centers of the two teeth 13 in the circumferential direction (see FIG. 7A). Accordingly, the magnetic body 31 can form a magnetic path between the two teeth 13.

  7A is a plan view in which the stator 100 having the magnetic body 31 attached is developed in the circumferential direction, and FIG. 7B is an elevation view of FIG. 7A. As shown in FIGS. 7 (a) and 7 (b), a part of the magnetic flux between the teeth 13 is a part of the teeth as shown by an arrow 91 in FIG. 7 (a) and an arrow 92 in FIG. 7 (b). It flows from 13 through the magnetic body 31 to the adjacent tooth 13. Therefore, in the stator 100 of the present embodiment, the yoke 12 is unlikely to cause magnetic saturation, and it is possible to output high torque while suppressing the radial increase in size of the stator core 11.

  Next, another embodiment will be described with reference to FIGS. The same parts as those described above with reference to FIGS. 1 to 7 are designated by the same reference numerals, and the description thereof will be omitted.

  As shown in FIG. 8, the stator 200 has an annular magnetic body 32 attached to the annular portion 11b. 9A is a plan view in which the stator 200 having the annular magnetic body 32 attached is developed in the circumferential direction, and FIG. 9B is an elevation view of FIG. 9A. As shown in FIGS. 9A and 9B, a part of the magnetic flux between the teeth 13 that are arranged apart from each other is indicated by an arrow 93 in FIG. 9A and an arrow in FIG. 9B. As shown by 94, it flows from the tooth 13 through the magnetic body 32 to another tooth 13 which is arranged apart. The stator 200 has the same effects as the stator 100 described above with reference to FIGS. 1 to 7.

  In each of the above embodiments, the coil end portion 18 is resin-molded, and then the magnetic members 31 and 32 are attached to the annular portion 11b between the outer periphery of the resin mold 21 and the outer periphery of the yoke 12, but the resin is used. The magnetic body 31 or the magnetic body 32 may be attached on the annular portion 11b between the outer side of the coil end portion 18 in the radial direction and the yoke 12 without performing molding.

  11 stator core, 11a, 13a axial end face, 11b annular part, 12 yoke, 13 teeth, 14 slots, 15 boss, 16 hole, 17 coil, 18 coil end part, 20 insulating member, 21 resin mold, 31, 32 magnetic body , 90 stator assembly, 91-94 arrows, 100, 200 stator.

Claims (1)

A method of manufacturing a stator,
A coil forming step of forming a coil by winding a conductor around the teeth of a stator core including an annular yoke and a plurality of teeth protruding inward in the radial direction from the inner peripheral surface of the yoke;
A part of the coil formed in the coil forming step, a resin molding step of molding a resin so as to cover the outer surface of the coil end portion projecting axially outward from the axial end surface of the tooth,
After the resin molding step, on the annular axial end surface of the yoke exposed between the outer side of the molded resin in the radial direction and the outer circumference of the yoke, between one tooth and another adjacent tooth. A magnetic body mounting step of mounting a magnetic body extending in the circumferential direction so as to form a magnetic path,
A method of manufacturing a stator, comprising: