Motor

Abstract

To suppress leakage of a resin onto a wire connection substrate surface.SOLUTION: A motor comprises: a stator; a substrate which is provided in the stator and includes a wire; and a resin member covering the stator. In a radial direction, the substrate includes an inner peripheral part, an outer peripheral part, and an intermediate part between the inner peripheral part and the outer peripheral part. In a direction of a rotation axis, the substrate includes a first face opposed to the stator and a second face at an opposite side of the first face. In the radial direction, the resin member includes a portion covering the substrate in the rotation axis direction and a portion covering an inner peripheral surface of the stator in the radial direction. A thickness of the portion of the resin member in the rotation axis direction is larger than a thickness of the portion of the resin member covering the inner peripheral surface of the stator in the radial direction.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to a motor. [Background technology]

[0002] 2. Description of the Related Art In a motor, a technique is known in which a wiring board is fixed to a stator by soldering, and then the stator is covered with resin. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2021 / 006200 Summary of the Invention [Problem to be solved by the invention]

[0004] When covering the stator with resin, resin leakage may occur and the resin may cover the surface of the wiring board. In particular, resin that leaks from the inner diameter side to the outer diameter side of the wiring board often covers the wiring board.

[0005] In one aspect, an object of the present invention is to provide a motor that can prevent resin from leaking onto the surface of a wiring board. [Means for solving the problem]

[0006] In one aspect, a motor comprises a stator, a substrate having wiring provided on the stator, and a resin member covering the stator, wherein in a radial direction, the substrate comprises an inner periphery, an outer periphery, and an intermediate portion between the inner periphery and the outer periphery, and in a direction of a rotation axis, the substrate comprises a first surface facing the stator and a second surface opposite the first surface, and the resin member comprises, in the radial direction, a portion covering the substrate in the rotation axis direction and a portion covering an inner periphery of the stator in the radial direction, and a thickness in the rotation axis direction of the portion of the resin member is greater than a thickness in the radial direction of the portion of the resin member covering the inner periphery of the stator.

[0007] According to one embodiment, leakage of the resin onto the surface of the wiring board can be suppressed. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a perspective view illustrating an example of a motor according to an embodiment. [Diagram 2] FIG. 2 is a perspective view illustrating an example of a stator before being covered with resin in the embodiment. [Diagram 3] FIG. 3 is an exploded perspective view illustrating an example of a stator before being covered with resin in the embodiment. [Figure 4] FIG. 4 is a side cross-sectional view showing an example of a molded stator in an embodiment. [Diagram 5] FIG. 5 is an enlarged cross-sectional view showing an example of a molded stator in an embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, an embodiment of a motor disclosed in the present application will be described in detail with reference to the drawings. Note that the dimensional relationships and ratios of each element in the drawings may differ from reality. The drawings may also include parts with different dimensional relationships and ratios. In order to make the description easier to understand, each drawing may show a coordinate system whose axial direction is the direction in which a shaft 99, which will be described later, extends.

[0010] [Embodiment] First, the motor in this embodiment will be described with reference to Figs. 1 to 3. Fig. 1 is a perspective view showing an example of a motor in this embodiment. Fig. 2 is a perspective view showing an example of a stator before being covered with resin in this embodiment. Fig. 3 is an exploded perspective view showing an example of a stator before being covered with resin in this embodiment. As shown in Fig. 1, the motor 1 in this embodiment includes a molded stator 4, a rotor 80, and a shaft 99. In this embodiment, the motor 1 is, for example, a frameless motor. In the following, the stator before being covered with a resin member 60 described later may be referred to as a stator 2, and the stator covered with the resin member 60 may be referred to as a molded stator 4.

[0011] The molded stator 4 shown in Fig. 1 is formed by covering the stator 2 to which the substrate 50 having wiring shown in Fig. 3 is fixed with a resin member 60 as shown in Fig. 2. That is, the molded stator 4 includes the stator 2, the substrate 50 having wiring provided on the stator 2, and the resin member 60 that covers the stator 2.

[0012] 3, the substrate 50 is fixed to the stator 2 from a first direction side in the axial direction. At that time, the first end 31 and the second end 32 of the coil 30, which will be described later, are fixed to lands 54, which will be described later, by solder S, thereby electrically connecting the coil 30 and the substrate 50.

[0013] The rotor 80 is disposed radially inside the molded stator 4. As shown in FIG. 1, the rotor 80 includes a magnet 81 and a rotor core 82. The magnet 81 is, for example, a cylindrical magnet fixed to the outer circumferential surface of the rotor core 82. The magnet 81 is, for example, formed of a rare earth magnet such as a neodymium magnet. The magnet 81 may be a bonded magnet or a sintered magnet. The magnet 81 is not limited to a cylindrical magnet, and may be a cylindrical magnet or a polygonal magnet. The magnet 81 may be embedded in the rotor core 82 instead of being fixed to the outer circumferential surface.

[0014] The shaft 99 is fixed to the inner circumferential surface of the rotor 80 as shown in Fig. 1, for example, and transmits driving force to an external device. Note that in Fig. 2 and subsequent figures, the rotor 80 and the shaft 99 may be omitted from illustration.

[0015] As shown in FIG. 3, the stator 2 includes a stator core 10, an insulator 20, and a coil 30. In the embodiment, the stator 2 is disposed so as to surround the rotor 80 shown in FIG. 1. The stator core 10 constituting the stator 2 is disposed, for example, in an annular shape along the circumferential direction. The stator core 10 is formed by stacking a plurality of plate-shaped metal members, such as soft magnetic steel plates such as silicon steel plates and electromagnetic steel plates, in the axial direction. As shown in FIG. 3, the stator core 10 includes an inner peripheral portion 11 facing the rotor 80, and an outer peripheral portion 12.

[0016] The insulator 20 is formed of an insulating material such as resin, etc. The insulator 20 covers the stator core 10 from a first direction side and a second direction side in the axial direction.

[0017] 2 and 3, the insulator 20 includes an inner peripheral portion 21 and an outer peripheral portion 22. As shown in Fig. 3, the outer peripheral portion 22 includes two recesses 24 and 25 cut out in a second axial direction. The inner peripheral portion 21 of the insulator 20 is an example of an inner peripheral surface of a stator.

[0018] As shown in Fig. 3, the coil 30 is formed by winding a conductor around the stator 2 via the insulator 20. As shown in Fig. 3, a first end 31 and a second end 32 of the conductor are drawn out in the same direction (first direction) from the coil 30 as lead wires.

[0019] In the embodiment, the stator 2 is formed by arranging the stator core 10, around which the coil 30 is wound with the insulator 20 interposed therebetween, in a circular shape.

[0020] In the embodiment, the substrate 50 is a wiring substrate having wiring formed by stacking insulating layers made of an insulating resin material such as epoxy and conductor layers made of metal or the like alternately in the axial direction.

[0021] As shown in Fig. 3, the substrate 50 has a surface 5a on a second axial direction side and a surface 5b on a first axial direction side. For example, as shown in Fig. 3, the substrate 50 is directly supported by the stator 2 so that the surface 5a faces the stator 2 in the axial direction. More specifically, the substrate 50 is supported at both ends in the radial direction by the inner circumferential portion 21 and the outer circumferential portion 22 of the insulator 20. The surface 5a is an example of a first surface facing the stator, and the surface 5b is an example of a second surface on the opposite side of the first surface.

[0022] In the embodiment, the surfaces 5a and 5b are formed of an insulator. In addition, a resin member (e.g., resist) is formed on the surface 5b as a member separate from the insulator. In the axial direction, a plurality of conductors and a plurality of insulators are stacked between the surfaces 5a and 5b. That is, the substrate 50 is formed by stacking a plurality of conductors and a plurality of insulators in the axial direction.

[0023] 3, a land 54 is formed on the substrate 50. The land 54 is made of a conductive material and is a connection portion that is connected to the first end 31 and the second end 32 of the conductive wire drawn out from the coil 30.

[0024] 3, an inner peripheral portion 53 and an outer peripheral portion 52 are formed on a surface 5b of a substrate 50. Further, an intermediate portion 55 is formed between the inner peripheral portion 53 and the outer peripheral portion 52 in the radial direction. That is, the substrate 50 includes the inner peripheral portion 53, the outer peripheral portion 52, and the intermediate portion 55 between the inner peripheral portion 53 and the outer peripheral portion 52 in the radial direction.

[0025] Pads 59 are arranged on the intermediate portion 55 of the front surface 5b as external connection portions for connection to an external device. The pads 59 in this embodiment include three pads 59A, 59B, and 59C corresponding to the three phases, respectively. Electronic components (not shown) are connected to the pads 59A to 59C.

[0026] Furthermore, on the surface 5b side of the substrate 50, a film 70 is provided on the inner peripheral portion 53 of the substrate 50. The film 70 is silk formed on a certain area on the substrate by screen printing using, for example, non-conductive ink, and a logo, letter, symbol, or the like (not shown) is formed. The film 70 is an example of a ring-shaped member.

[0027] The resin member 60 is formed, for example, by filling a liquid resin in a state where the stator 2 to which the substrate 50 is attached is placed in a mold, and then hardening the resin. The resin member 60 may be a thermosetting resin or a thermoplastic resin. In the embodiment, the resin forming the resin member 60 contains, for example, aluminum or silicon. In this case, the rigidity of the resin forming the insulator 20 is greater than the rigidity of the resin forming the resin member 60, for example.

[0028] In addition, the mold in the embodiment has a gas vent formed on the inside in the radial direction and on the first direction side in the axial direction. The gas vent is, for example, a hole formed in the mold and connected to the outside.

[0029] In this case, the inner peripheral portion 21 of the insulator 20 shown in FIG. 2 is covered by the inner peripheral surface 61 of the resin member 60 from, for example, the inside in the radial direction as shown in FIG. 1, and is not visible. The outer peripheral portion 22 of the insulator 20 is covered by the outer peripheral surface 64 of the resin member 60 from, for example, the outside in the radial direction. The inner peripheral surface 61 of the resin member 60 is an example of a portion that covers the inner peripheral surface of the stator in the radial direction. In the radial direction, the thickness of the portion (outer peripheral portion) of the resin member 60 having the outer peripheral surface 64 is smaller than the thickness of the other portion (inner peripheral portion) of the resin member 60 having the inner peripheral surface 61. By making the other portion (inner peripheral portion) of the resin member 60 thinner than the resin member portion, a gap between the rotor 80 and the stator 2 in the circumferential direction can be secured, and a uniform gap can be formed in the circumferential direction.

[0030] Also, for example, in the radial direction and the axial direction, a part of the outer circumferential portion 52 is covered by an outer circumferential portion 62 of the resin member 60. The inner circumferential portion 63 is an example of a portion of the resin member adjacent to the annular member, and the outer circumferential portion 62 is an example of a portion covering the outer circumferential portion of the substrate. In this case, the resin member 60 includes a portion 63 that is adjacent to the annular member 70 in the radial direction and covers the substrate 50 in the rotation axis direction, and a portion 61 that covers the inner circumferential surface 21 of the stator 2 in the radial direction. Also, the resin member 60 includes a portion 62 that covers the outer circumferential portion 52 of the substrate 50 in the rotation axis direction.

[0031] Fig. 4 is a side cross-sectional view showing an example of a molded stator in an embodiment. Fig. 4 shows a cross section cut along a plane P1 in Fig. 1. As shown in Fig. 4, in the molded stator 4, the stator core 10 is covered with a resin member 60 except for an inner peripheral portion 11 and an outer peripheral portion 12. The inner peripheral portion 11 and the outer peripheral portion 12 of the stator core 10 are exposed to the resin member 60. The insulator 20 is entirely covered with a resin member 60 .

[0032] Moreover, the surface 5a of the substrate 50 faces the stator 2 in the axial direction and is in contact with an intermediate portion (support portion) 65 of the resin member 60. The support portion 65 is located between an outer peripheral portion 62 of the resin member 60 and an inner peripheral surface 61, faces the coil 30 of the stator 2, and is located in the gap between the coil 30 and the substrate 50. In the embodiment, the surface 5a of the substrate 50 is supported on both radial sides from the second axial direction side by, for example, the inner peripheral portion 21 and the outer peripheral portion 22 of the insulator 20.

[0033] In the molded stator 4 shown in Figure 4, as described above, of the surface 5b of the substrate 50, a portion of the inner circumferential portion 53 is covered by a portion 63 of the inner circumferential portion of the resin member 60, and a portion of the outer circumferential portion 52 is covered by a portion 62 of the outer circumferential portion of the resin member 60.

[0034] Fig. 5 is an enlarged cross-sectional view showing an example of a molded stator in an embodiment, Fig. 5 is an enlarged view of a portion shown in a frame F1 in Fig. 4.

[0035] When resin is filled into a mold to form the molded stator 4, the liquid resin may leak out from the gap between the mold and the stator 2. For example, even when a film 70 such as silk is provided on the substrate 50, it may be difficult to completely seal the gap between the mold and the substrate 50.

[0036] In contrast, when the gas vent of the mold is located on the first direction side in the rotation axis direction with respect to the inner peripheral portion 53 of the substrate 50 as in the embodiment, the resin filled in the portion covering the inner peripheral portion 53 of the substrate 50 leaks out in the first direction in the axial direction. As a result, a part 63 of the inner peripheral side of the resin member 60 is formed as a burr, and the part 63 of the inner peripheral side of the resin member 60 extends in the first direction in the axial direction.

[0037] According to this configuration, the resin filled in the portion covering the inner periphery 53 of the substrate 50 is prevented from leaking outward in the radial direction. Moreover, the middle portion 55 is not covered by the film 70. In this configuration, the middle portion 55 is exposed to the resin member 60.

[0038] In this case, as shown in FIG. 4, a thickness T3 of the inner peripheral portion 63 in the rotation axis direction is greater than a thickness T1 of the portion 61 covering the inner peripheral portion 21 of the insulator 20 in the radial direction.

[0039] 4, the outer peripheral portion 62 of the resin member 60 covers the solder S connecting the substrate 50 and the coil 30 from the first axial direction. Since the solder S protrudes further in the first axial direction than the substrate 50, the outer peripheral portion 62 of the resin member 60 has a larger thickness T2 in the axial direction. In this case, the thickness T3 in the axial direction of the inner peripheral portion 63 is smaller than the thickness T2 in the axial direction of the outer peripheral portion 62 covering the outer peripheral portion 52 of the substrate 50.

[0040] As described above, the motor 1 in this embodiment includes the stator 2, the substrate 50 having wiring provided on the stator 2, and the resin member 60 covering the stator 2. In the radial direction, the substrate 50 includes an inner peripheral portion 53, an outer peripheral portion 52, and an intermediate portion 55 between the inner peripheral portion 53 and the outer peripheral portion 52. In the direction of the rotation axis, the substrate 50 includes a first surface 5a facing the stator 2 and a second surface 5b on the opposite side of the first surface 5a. In the radial direction, the resin member 60 includes a portion 63 covering the substrate 50 in the rotation axis direction and a portion 61 covering the inner peripheral surface 21 of the stator 2 in the radial direction. The thickness T3 of the portion 63 of the resin member 60 in the rotation axis direction is greater than the thickness T1 in the radial direction of the portion 61 of the resin member 60 covering the inner peripheral surface 21 of the stator 2. With this configuration, it is possible to suppress the resin from leaking onto the surface of the wiring board without changing the shape of the substrate 50.

[0041] [Variations] Although the configuration of this embodiment has been described above, the embodiment is not limited to this. For example, the configuration of the annular member provided on the inner peripheral portion 53 of the substrate 50 is not limited to silk printing, and other structures such as a resin annular member may be used. In addition, the motor 1 may be configured without including the membrane 70, which is an annular member.

[0042] 5, the radial thickness of the portion 66 of the resin member 60 facing the substrate 50 in the radial direction is formed to be thicker than the thickness T1 of the inner circumferential surface 61 covering the inner circumferential portion 21 of the insulator 20, but the embodiment is not limited to this. For example, the radial thickness of the portion 66 may be substantially the same as the thickness T1.

[0043] The gas vent may be formed in any position other than the first direction side in the rotation axis direction as long as it is a position that can prevent the resin from leaking outward in the radial direction, and may be formed in other directions such as the inner circumferential side in the radial direction. Note that the gas vent is, for example, a through hole formed in the mold, but is not limited to this and may be a gap formed between a pin and a core of the mold.

[0044] Although the present invention has been described above based on the embodiment and each modification, it goes without saying that the present invention is not limited to the embodiment and each modification, and various modifications are possible within the scope of the gist of the present invention. Such modifications that do not depart from the scope of the gist are also included in the technical scope of the present invention, and this will be clear to those skilled in the art from the description of the claims. [Explanation of symbols]

[0045] 1 motor, 2 stator, 4 molded stator, 5a, 5b surface, 10 stator core, 11 inner periphery, 12 outer periphery, 20 insulator, 21 inner periphery, 22 outer periphery, 30 coil, 31 first end, 32 second end, 50 substrate, 52 outer periphery, 53 inner periphery, 54 land, 55 middle part, 59 pad, 60 resin member, 61 inner periphery, 62 part of outer periphery, 63 part of inner periphery, 64 outer periphery, 65 support part, 70 film, 80 rotor, 81 magnet, 82 rotor core, 99 shaft

Claims

1. a stator; a substrate provided on the stator and having wiring; a resin member covering the stator; Equipped with In a radial direction, the substrate includes an inner circumferential portion, an outer circumferential portion, and an intermediate portion between the inner circumferential portion and the outer circumferential portion; the substrate has a first surface facing the stator and a second surface opposite to the first surface in a direction of the rotation axis; the resin member includes, in a radial direction, a portion that covers the substrate in the rotation axis direction and a portion that covers an inner circumferential surface of the stator in the radial direction; a thickness of the resin member in the rotation axis direction is greater than a thickness of the resin member covering the inner peripheral surface of the stator in the radial direction; Motor.

2. the resin member includes a portion that covers an outer periphery of the substrate in a rotation axis direction, a thickness of the resin member in the rotation axis direction is smaller than a thickness of the portion covering the outer periphery of the substrate in the rotation axis direction; The motor according to claim 1 .

3. The motor according to claim 1 or 2, wherein the intermediate portion is exposed from the resin member.

4. an annular member is provided on an inner periphery of the substrate on the second surface side of the substrate; The resin member is adjacent to the annular member in the radial direction.

3. The motor according to claim 1 or 2.

Images