WO2017094525A1

WO2017094525A1 - Stator, motor, and method for manufacturing stator

Info

Publication number: WO2017094525A1
Application number: PCT/JP2016/084210
Authority: WO
Inventors: 良樹河合; 智哉上田; 祐輔牧野
Original assignee: 日本電産株式会社
Priority date: 2015-12-01
Filing date: 2016-11-18
Publication date: 2017-06-08
Also published as: CN108292867B; JP6806081B2; CN108292867A; JPWO2017094525A1

Abstract

In a stator according to one aspect of the present invention, a stator core is configured such that a plurality of electromagnetic steel sheets are laminated in the radial direction. The stator core has: a core columnar part extending in the axial direction, a coil being wound around the core columnar part; and a sheet-form flange part connected to an axial-direction end of the core columnar part, the flange part extending in the circumferential direction. The flange part has a widening part in which the circumferential-direction width increases from the radially inward side toward the radially outward side, and a radially extending fixed-width part of substantially fixed circumferential-direction width. The fixed-width part is configured such that a plurality of electromagnetic steel sheets of substantially fixed circumferential-direction width are laminated in the radial direction in the flange part. A plastic part has: a plastic body part, at least a portion of which being positioned between circumferentially adjacent flange parts; and a first recess part indented in the axial direction beyond the axial-direction end surface of the plastic body part and positioned between circumferentially adjacent fixed-width parts of the stator core.

Description

Stator, motor, and stator manufacturing method

The present invention relates to a stator, a motor, and a method for manufacturing a stator.

Conventionally, an electric motor having a plurality of core members arranged in an annular shape around the axis of the rotor output shaft is known. For example, the core member of the electric motor in Patent Document 1 is composed of a laminated steel plate in which electromagnetic steel plates are laminated along the radial direction of the stator.

Japanese Publication No. 2011-114993

In the core member in which the electromagnetic steel plates are laminated along the radial direction of the stator, the circumferential end of the core member is constituted by the circumferential ends of the plurality of electromagnetic steel plates. Here, it becomes difficult to accurately form the circumferential end of the core member. Therefore, when a core member is positioned on the basis of the circumferential direction edge part of a core member, there existed a problem that the arrangement | positioning precision of a core member fell. If the positioning of the core member in the circumferential direction or the radial direction varies, torque ripple increases and causes vibration of the motor.

On the other hand, in Patent Document 1, for example, the flange portion of the insulator is provided with a connecting means for connecting the core members to each other in the circumferential direction. However, in this case, there is a problem that the size of the stator is increased because the insulator is easily increased in size.

In view of the above problems, one aspect of the present invention provides a stator having a structure capable of improving the arrangement accuracy of a plurality of stator cores while suppressing an increase in size, and a motor including such a stator. Is one of the purposes. Another object of the present invention is to provide a stator manufacturing method capable of improving the arrangement accuracy of a plurality of stator cores while suppressing an increase in size.

A stator according to one aspect of the present invention is a stator that is axially opposed to a rotor that rotates about a central axis that extends in the vertical direction and a gap, and a plurality of stator cores that are arranged along a circumferential direction, A coil wound around the stator core, an insulator at least part of which is located between the stator core and the coil, and a resin part at least part of which is located between the stator cores adjacent in the circumferential direction are provided. The stator core has a configuration in which a plurality of electromagnetic steel plates are laminated in the radial direction. The stator core includes a core columnar portion extending in the axial direction and around which a coil is wound, and a plate-like flange portion extending in the circumferential direction connected to the axial end portion of the core columnar portion. The flange portion has an enlarged portion whose circumferential width increases from the radially inner side toward the radially outer side, and an equal width portion having the substantially same circumferential width and extending in the radial direction. The equal width portion has a configuration in which a plurality of electromagnetic steel sheets having substantially the same circumferential width are stacked in the radial direction. The resin part is a resin main body part at least partially located between the flange parts adjacent to each other in the circumferential direction, and a constant width part of the stator core that is recessed in the axial direction from the axial end surface of the resin main body part and adjacent in the circumferential direction. And a first recess located between them.

A motor according to one aspect of the present invention includes the above-described stator, a rotor that is axially opposed to the stator via a gap, and a shaft that rotatably supports the rotor.

A method for manufacturing a stator according to one aspect of the present invention is a method for manufacturing a stator that is axially opposed to a rotor that rotates about a central axis that extends in the up-down direction, with a gap therebetween. A step S1 of forming a plurality of stator cores by stacking, a step S2 of attaching a coil to the stator core, a step S3 of arranging a plurality of stator cores in the circumferential direction in the mold, and a resin melted in the mold And forming a resin portion located at least partially between the stator cores adjacent in the circumferential direction. The stator core includes a core columnar portion that extends in the axial direction and is wound with a coil, and a plate-like flange portion that is connected to the axial end of the core columnar portion and extends in the radial direction. The flange portion has an enlarged portion whose circumferential width increases from the radially inner side toward the radially outer side, and an equal width portion having the substantially same circumferential width and extending in the radial direction. The equal width portion has a configuration in which a plurality of electromagnetic steel sheets having substantially the same circumferential width in the flange portion are stacked in the radial direction. In step S3, the stator core is positioned in the circumferential direction by bringing the equal width portion into contact with the first positioning member disposed in the mold.

According to one aspect of the present invention, a stator having a structure capable of improving the arrangement accuracy of a plurality of stator cores while suppressing an increase in size, and a motor including such a stator are provided. Moreover, according to one aspect of the present invention, there is provided a method for manufacturing a stator capable of improving the arrangement accuracy of a plurality of stator cores while suppressing an increase in size.

FIG. 1 is a cross-sectional view showing the motor of this embodiment. FIG. 2 is a perspective view showing the stator of the present embodiment. FIG. 3 is a perspective view showing the stator core of the present embodiment. FIG. 4 is a view showing the stator core of the present embodiment and is a cross-sectional view taken along the line IV-IV in FIG. FIG. 5 is a perspective view of the stator of this embodiment as viewed from below. FIG. 6 is a cross-sectional view showing a portion of the stator of the present embodiment. FIG. 7 is a flowchart showing a procedure in the stator manufacturing method of the present embodiment. FIG. 8 is a diagram illustrating an installation process in the stator manufacturing method of the present embodiment. FIG. 9 is a cross-sectional view showing a stator core which is another example of the present embodiment.

Hereinafter, a motor according to an embodiment of the present invention will be described with reference to the drawings. In the following description, the direction in which the central axis J in FIG. The upper side in the axial direction of the central axis J in FIG. 1 is simply referred to as “upper side”, and the lower side is simply referred to as “lower side”. The vertical direction is simply a name used for explanation, and does not limit the actual positional relationship or direction. In addition, a direction parallel to the central axis J is simply referred to as “axial direction”, a radial direction around the central axis J is simply referred to as “radial direction”, and a circumferential direction around the central axis J is simply referred to as “circumferential direction”. "

In this specification, “extending in the axial direction” includes not only the case of extending in the axial direction but also the case of extending in a direction inclined by less than 45 ° with respect to the axial direction. “Extending in the radial direction” includes not only strictly extending in the radial direction, that is, in a direction perpendicular to the axial direction, but also extending in a direction inclined by less than 45 ° with respect to the radial direction. .

The motor 10 of this embodiment shown in FIG. 1 is an axial gap type motor. The motor 10 includes a housing 11, a shaft 20,

rotors

31 and 32, a stator 40, an upper bearing 51, and a lower bearing 52. The shaft 20 is disposed around the central axis J. The shaft 20 supports the

rotors

31 and 32 in a rotatable manner. The

rotors

31 and 32 rotate around a central axis J that extends in the vertical direction. The

rotors

31 and 32 face the stator 40 in the axial direction through a gap. The

rotors

31 and 32 have

rotor magnets

33 and 35 that face the stator 40 in the axial direction. Only one of the

rotors

31 and 32 may be provided.

The stator 40 is positioned between the rotor 31 and the rotor 32 in the axial direction. The stator 40 is opposed to the

rotors

31 and 32 in the axial direction through a gap. As shown in FIGS. 1 and 2, the stator 40 includes a plurality of stator cores 41, a plurality of coils 42, an insulator 43, a resin portion 46, a bearing holder 44, and a cover 45. The stator 40 may be provided so as to face either of the

rotors

31 and 32 in the axial direction.

As shown in FIG. 2, the plurality of stator cores 41 are arranged along the circumferential direction. The number of stator cores 41 is not particularly limited. In FIG. 2, twelve stator cores 41 are provided. The stator core 41 has a substantially fan shape that extends in the circumferential direction from the radially inner side to the radially outer side when viewed in the axial direction.

As shown in FIG. 3, the stator core 41 has a configuration in which a plurality of electromagnetic steel plates 41a are laminated in the radial direction. The electromagnetic steel plate 41a is a substantially H-shaped flat plate as viewed in the radial direction. The radial end surface of the electromagnetic steel plate 41a is substantially orthogonal to the radial direction passing through the center in the circumferential direction of the stator core 41 when viewed in the axial direction. Both end surfaces in the circumferential direction of the electromagnetic steel plate 41a are substantially parallel to the radial direction passing through the center in the circumferential direction of the electromagnetic steel plate 41a.

The electromagnetic steel plate 41a has a stator core recess 41e that is recessed in a direction orthogonal to the radial direction. In FIG. 3, the stator core recess 41 e is recessed in the axial direction. The stator core recess 41e is provided at both axial ends of the electromagnetic steel plate 41a. The internal shape of the stator core recess 41e is rectangular when viewed in the radial direction. The stator core recess 41e may be recessed in any direction as long as the direction is orthogonal to the radial direction. Further, the stator core recess 41e may be recessed in the circumferential direction.

The stator core 41 has a core columnar portion 41b that extends in the axial direction and is wound with a coil 42, and a plate-like flange portion 41c that is connected to the axial end of the core columnar portion 41b and extends in the circumferential direction. The flange portion 41c extends from the axial end portion of the core columnar portion 41b to both sides in the circumferential direction. The flange portions 41c are provided at both axial ends of the core columnar portion 41b.

3 and 4, the flange portion 41c has an enlarged portion 47b and a uniform width portion 47a. The enlarged portion 47b is a portion whose circumferential width increases from the radially inner side toward the radially outer side. That is, in the plurality of electromagnetic steel plates 41a constituting the enlarged portion 47b, the electromagnetic steel plate 41a located on the radially outer side has a larger circumferential width in the flange portion 41c than the electromagnetic steel plate 41a located on the radially inner side. As described above, both ends in the circumferential direction of the electromagnetic steel sheet 41a are parallel to the radial direction passing through the center in the circumferential direction of the electromagnetic steel sheet 41a. Therefore, the electromagnetic steel plates 41a having different circumferential widths in the flange portion 41c are laminated in the radial direction, so that both circumferential ends of the enlarged portion 47b are stepped.

In the present specification, the “circumferential width” is a dimension in a direction perpendicular to the radial direction when viewed in the axial direction. The “direction orthogonal to the radial direction” includes a direction orthogonal to the radial direction passing through the center of the circumferential direction of a certain target. As an example, the circumferential width of the stator core 41 includes the dimension of the stator core 41 in a direction orthogonal to the radial direction passing through the center in the circumferential direction of the stator core 41 when viewed in the axial direction.

The equal width portion 47a is a portion that has the same circumferential width in the stator core 41 and extends in the radial direction. The equal width portion 47a extends radially outward from the radially outer end of the enlarged portion 47b. The equal width portion 47a is configured such that a plurality of electromagnetic steel plates 41a having substantially the same circumferential width in the flange portion 41c are stacked in the radial direction. The equal width part 47a is located on the radially outer side than the enlarged part 47b. Therefore, compared to the case where the equal width portion 47a is provided at the center in the radial direction of the flange portion 41c, the shape of the stator core 41 can be easily made a shape having excellent magnetic characteristics.

The circumferential width of the equal width portion 47a is larger than the circumferential width of the electromagnetic steel plate 41a located at the radially outer end of the enlarged portion 47b. The difference between the circumferential width of the equal width portion 47a and the circumferential width of the electromagnetic steel plate 41a located at the radially outer end of the enlarged portion 47b is the circumferential width of the electromagnetic steel plates 41a adjacent in the radial direction in the enlarged portion 47b. It is about the same as the difference.

3 and 4, the number of electromagnetic steel plates 41a constituting the equal width portion 47a is three. The number of electromagnetic steel plates 41a constituting the equal width portion 47a may be two, or four or more. The shapes of the plurality of electromagnetic steel plates 41a constituting the equal width portion 47a are the same as each other. In addition, the shape of the some electromagnetic steel plate 41a which comprises the equal width part 47a may mutually differ. In this case, the circumferential widths of the plurality of electromagnetic steel plates 41a may be different from each other in the core columnar portion 41b. The circumferential end surface of the equal width portion 47a is a substantially flat surface in which the circumferential end surfaces of the plurality of electromagnetic steel plates 41a are continuously formed.

As shown in FIG. 3, the flange surface 41 h that is a surface facing the

rotors

31 and 32 in the flange portion 41 c includes a main body surface 41 g and a step surface 41 f. The flange surface 41 h is an axial end surface of the stator core 41. The step surface 41f is recessed closer to the core columnar portion 41b in the axial direction than the main body surface 41g. That is, the axial end surface of the stator core 41 has a step surface 41f that is recessed toward the coil 42 (core columnar portion 41b) in the axial direction.

The step surface 41f is provided on both sides in the circumferential direction of the main body surface 41g. The step surface 41f is located at both circumferential ends of the flange surface 41h. Therefore, as the

rotors

31 and 32 rotate, the surface on which the

rotor magnets

33 and 35 face changes in the order of the step surface 41f, the main body surface 41g, and the step surface 41f in one stator core 41. As a result, the axial distance between the

rotor magnets

33 and 35 and the flange surface 41h is reduced by changing from the step surface 41f to the main body surface 41g, and is increased by changing from the main body surface 41g to the step surface 41f. By changing the axial distance between the

rotor magnets

33 and 35 and the flange surface 41h in this way, the waveform of the counter electromotive voltage generated in the motor 10 can be made closer to a sine wave. Further, the cogging torque of the motor 10 can be reduced. Thereby, the magnetic characteristics of the motor 10 can be improved.

The step surface 41f extends from the radially inner end of the flange surface 41h to the radially outer end. The step surface 41f is a substantially flat surface in which the axial end surfaces of the plurality of electromagnetic steel plates 41a are continuously formed. The circumferential width of the step surface 41f is substantially the same over the entire radial direction.

The main body surface 41g is located at the center in the circumferential direction of the flange surface 41h. As shown in FIGS. 2 and 5, the main body surfaces 41 g on both sides in the axial direction are exposed from the resin portion 46 to the outside of the stator 40. Thereby, when forming the resin part 46 using the metal mold | die D, the stator core 41 can be arrange | positioned in the metal mold | die D in the state which made the main body surface 41g contact the bottom face Da of the metal mold | die D. FIG. Therefore, the stator core 41 can be accurately arranged in the axial direction. The main body surface 41g may not be exposed to the outside of the stator 40. In this case, the main body surface 41g may be covered with a part of the resin portion 46.

The circumferential width of the portion of the main body surface 41g located at the enlarged portion 47b increases from the radially inner side toward the radially outer side. A portion of the main body surface 41g located in the equal width portion 47a has a circumferential width that is substantially the same over the entire radial direction, and extends in the radial direction. Thus, the circumferential width of the main body surface 41g changes in the same manner as the circumferential width of the flange portion 41c along the radial direction. Thereby, the magnetic characteristic of the stator core 41 can be made suitable according to a radial direction position. This configuration can be adopted by making the circumferential width of the step surface 41f substantially the same over the entire radial direction.

The stator core 41 has a groove portion 47c that is configured by a plurality of stator core concave portions 41e and extends in the radial direction. Therefore, it is possible to employ a method of laminating a plurality of electromagnetic steel plates 41a in the radial direction while positioning the electromagnetic steel plates 41a by the stator core recesses 41e. Thereby, the electromagnetic steel plates 41a can be stacked with high accuracy, and the stator core 41 can be manufactured with high accuracy. Therefore, the circumferential end surface of the equal width portion 47a can be configured with high accuracy, and the placement accuracy of the stator core 41 can be further improved when a method for manufacturing the stator 40 described later is used.

The groove portion 47c extends from the radially inner end of the flange portion 41c to the radially outer end. The groove portion 47 c is recessed in the axial direction from the axial end surface of the stator core 41. More specifically, the groove 47c is recessed from the main body surface 41g toward the core columnar portion 41b. In the present embodiment, since the stator core concave portion 41e is provided on both axial end surfaces of the electromagnetic steel plate 41a, the groove portion 47c is provided on both axial end surfaces of the stator core 41. The groove portion 47c is located at the center of the flange portion 41c in the circumferential direction.

In addition, the groove part 47c may be provided in the core columnar part 41b. In this case, the groove portion 47c is recessed in the circumferential direction from the circumferential end surface of the core columnar portion 41b. Moreover, the stator core recessed part 41e which comprises the groove part 47c is dented in the circumferential direction, and is provided in the part which comprises the core columnar part 41b in the electromagnetic steel plate 41a.

As shown in FIG. 4, the circumferential width of the core columnar portion 41b changes in the same manner as the circumferential width of the flange portion 41c. That is, the core columnar portion 41b includes an enlarged columnar portion 49b whose circumferential width increases from the radially inner side to the radially outer side, and an equal-width columnar portion 49a that has substantially the same circumferential width and extends in the radial direction. Have. The radial position of the enlarged columnar portion 49b is the same as the radial position of the enlarged portion 47b. The radial position of the equal width columnar portion 49a is the same as the radial position of the equal width portion 47a. With this configuration, the magnetic characteristics of the stator core 41 can be made suitable according to the radial position.

The radial position of the enlarged columnar portion 49b and the radial position of the enlarged portion 47b may be shifted in the radial direction. The radial position of the equal width columnar portion 49a and the radial position of the equal width portion 47a may be shifted in the radial direction. Further, the change in the circumferential width of the core columnar portion 41b may be different from the change in the circumferential width of the flange portion 41c. The circumferential width of the core columnar portion 41b may be substantially the same over the entire radial direction, or may increase as it goes from the radially inner side to the radially outer side over the entire radial direction.

As shown in FIG. 1, the coil 42 is wound around the stator core 41. More specifically, the coil 42 is wound around the core columnar portion 41 b via the insulator 43. That is, at least a part of the insulator 43 is located between the stator core 41 and the coil 42.

As shown in FIGS. 1 and 2, the bearing holder 44 has a cylindrical shape extending in the axial direction about the central axis J. An upper bearing 51 is held inside the bearing holder 44 in the radial direction. The cover 45 has an annular shape that surrounds the radially outer sides of the plurality of stator cores 41.

As shown in FIG. 2, at least a part of the resin portion 46 is located between the stator cores 41 adjacent in the circumferential direction. The resin portion 46 connects the plurality of stator cores 41, the bearing holder 44, and the cover 45. The resin part 46 includes an inner annular part 46b, an outer annular part 46c, and a resin main body part 46a. The inner annular portion 46 b is an annular portion located between the bearing holder 44 and the stator core 41 in the resin portion 46 in the radial direction. The outer annular portion 46 c is an annular portion located on the radially outer side of the stator core 41 in the resin portion 46.

As shown in FIG. 5 and FIG. 6, the resin main body portion 46 a is a portion located between the stator cores 41 adjacent to each other in the circumferential direction in the resin portion 46. Further, at least a part of the resin main body 46a is located between the flanges 41c adjacent in the circumferential direction. As shown in FIG. 5, the radially inner end of the resin main body 46a is connected to the inner annular portion 46b. A radially outer end of the resin main body 46a is connected to the outer annular portion 46c. As shown in FIG. 6, the resin main body 46a includes a portion located between the flange portions 41c adjacent in the circumferential direction and a portion located between the core columnar portions 41b adjacent in the circumferential direction. . The main body portion end surface 46d, which is the axial end surface of the resin main body portion 46a, is at the same position as the main body surface 41g in the axial direction.

As shown in FIG. 5, the resin portion 46 has a first recess 48a and a second recess 48b. In the present embodiment, the first recess 48 a and the second recess 48 b are provided on the lower surface 40 b of the stator 40. As shown in FIG. 6, the first recess 48a is recessed in the axial direction from the main body end face 46d. More specifically, the first recess 48a is recessed above the main body end surface 46d. As shown in FIGS. 5 and 6, the first recess 48 a is located between the equal width portions 47 a of the stator core 41 adjacent in the circumferential direction. Therefore, the stator core 41 can be accurately arranged in the circumferential direction by adopting a method for manufacturing the stator 40 of the present embodiment described later.

As shown in FIG. 5, the first recesses 48 a are respectively provided between the equal width portions 47 a of the stator cores 41 adjacent in the circumferential direction. The plurality of first recesses 48a are equally arranged along the circumferential direction.

The outer shape of the first recess 48a viewed in the axial direction is not particularly limited, and may be a polygonal shape or a circular shape. In FIG. 5, the outer shape of the first recess 48a viewed in the axial direction is trapezoidal. The circumferential width of the first recess 48a increases from the radially inner side toward the radially outer side. The surface on the one circumferential side (+ θ side) of the inner surface of the first recess 48a is substantially parallel to the equal width portion 47a of the stator core 41 located on the one circumferential side (+ θ side) of the first recess 48a. The surface on the other circumferential side (−θ side) of the inner surface of the first recess 48a is substantially parallel to the equal width portion 47a of the stator core 41 located on the other circumferential side (−θ side) of the first recess 48a. is there.

At least a part of the equal width portion 47a is exposed in the first recess 48a. More specifically, at least a part of the circumferential end surface of the equal width portion 47a is exposed in the first recess 48a. In addition, the equal width part 47a does not need to be exposed in the 1st recessed part 48a. In this case, the circumferential end surface of the equal width portion 47 a is covered with a part of the resin portion 46.

As shown in FIG. 6, the bottom surface of the first recess 48a is in a position shallower than the region where the coil 42 is disposed in the axial direction. Therefore, it is possible to prevent the first recess 48a from reaching the coil 42 and the coil 42 from being exposed in the first recess 48a. The bottom surface of the first recess 48a is at a position shallower than the axial end surface on the core columnar portion 41b side (upper side) of the lower flange portion 41c. That is, the height position in the axial direction of the bottom surface of the first recess 48a is located below the upper surface in the axial direction of the lower flange portion 41c.

As shown in FIG. 5, the second recess 48b is recessed in the axial direction from the main body end face 46d. The second recess 48b is located in the inner annular portion 46b. At least a part of the second recess 48 b is located on the radially inner side of the radially inner end of the stator core 41. In FIG. 5, the entire second recess 48 b is located on the radially inner side of the radially inner end of the stator core 41. Therefore, the stator core 41 can be accurately arranged in the radial direction by employing a method for manufacturing the stator 40 of the present embodiment, which will be described later. The radially inner end of the stator core 41 is the radially inner end of the flange portion 41c.

The second recess 48b is provided each time the stator core 41 is disposed. The plurality of second recesses 48b are evenly arranged in the circumferential direction. The second recess 48b is located on the inner side in the radial direction than the first recess 48a. The circumferential position of the second recess 48b is between the first recesses 48a adjacent in the circumferential direction. In FIG. 5, the second recess 48 b is provided one by one every time the stator core 41 is disposed, but the present invention is not limited to this. Two or more second recesses 48b may be provided each time the stator core 41 is disposed.

The outer shape of the second recess 48b viewed in the axial direction is not particularly limited, and may be a polygonal shape or a circular shape. In FIG. 5, the shape of the second recess 48b viewed in the axial direction is circular. Although illustration is omitted, at least a part of the radially inner end of the stator core 41 is exposed in the second recess 48b. More specifically, at least a part of the radially inner end surface of the flange portion 41c is exposed in the second recess 48b. Note that at least a part of the radially inner end of the stator core 41 may not be exposed in the second recess 48b. In this case, the radially inner end surface of the flange portion 41 c is covered with a part of the resin portion 46.

As shown in FIG. 6, a part of the resin portion 46 is disposed on the axial end surface of the stator core 41. Specifically, a part of the resin portion 46 is disposed on the step surface 41f. Therefore, the stator core 41 is pressed from both sides in the axial direction by a part of the resin portion 46. Therefore, it is possible to suppress the stator core 41 from moving in the axial direction with respect to the resin portion 46. Thereby, the stator core 41 and the resin part 46 can be fixed more firmly.

In the present embodiment, by providing the step surface 41f, it is possible to expose the main body surface 41g while disposing a part of the resin portion 46 on the step surface 41f. Thereby, the stator core 41 can be accurately arranged in the axial direction while fixing the stator core 41 and the resin portion 46 firmly.

A part of the resin part 46 is disposed in the groove part 47c. In the present embodiment, a part of the resin part 46 is filled in the entire groove part 47c.

As shown in FIG. 7, the method for manufacturing the stator 40 of the present embodiment includes a stator core forming step S1, a coil mounting step S2, an arrangement step S3, and a resin molding step S4. The stator core formation step S1 is a step of forming a plurality of stator cores 41 by laminating a plurality of electromagnetic steel plates 41a in the radial direction. A part of the strip-shaped electromagnetic steel sheet is punched out by press working to form a plurality of electromagnetic steel sheets 41a. The electromagnetic steel sheets 41a are stacked while aligning the positions of the electromagnetic steel sheets 41a by fitting a jig into the stator core recess 41e. Therefore, the plurality of electromagnetic steel plates 41a can be accurately stacked. The method for fixing the electromagnetic steel sheets 41a is not particularly limited.

The coil mounting step S2 is a step of mounting the coil 42 on the stator core 41. After the insulator 43 is mounted on the core columnar portion 41 b, a conductive wire is wound around the core columnar portion 41 b from above the insulator 43 to form the coil 42.

As shown in FIG. 8, the arrangement step S3 is a step of arranging a plurality of stator cores 41 in the mold D along the circumferential direction. The mold D is, for example, a cylindrical shape. In the mold D, a first positioning member P1 and a second positioning member P2 are arranged. The first positioning member P1 and the second positioning member P2 are fixed to the bottom surface Da of the mold D. A plurality of first positioning members P1 are provided along the circumferential direction. A plurality of second positioning members P2 are provided along the circumferential direction. The second positioning member P2 is located on the radially inner side than the first positioning member P1. The circumferential position of the second positioning member P2 is between the first positioning members P1 adjacent to each other in the circumferential direction. The shape of the first positioning member P1 viewed in the axial direction is a trapezoid. The shape of the second positioning member P2 viewed in the axial direction is circular.

The stator core 41 is disposed in the mold D in a state where the main body surface 41g of the lower flange portion 41c is in contact with the bottom surface Da. In the arranging step S3, the equal width portion 47a is brought into contact with the first positioning member P1 arranged in the mold D, and the stator core 41 is positioned in the circumferential direction.

When the flange portion is composed only of the enlarged portion, for example, the enlarged portion is positioned by contacting the positioning member. However, since the circumferential end of the enlarged portion is stepped, it is difficult to accurately position the stator core. In addition, the contact between the positioning member and the stator core tends to be unstable, and when the resin is poured into the mold, the stator core may move due to the pressure of the resin. Therefore, it is difficult to arrange the stator core with high accuracy. In order to deal with this problem, it is conceivable to provide a structure for positioning the insulator. In that case, however, the insulator is likely to be enlarged and the stator is enlarged.

For these problems, the equal width portion 47a has a configuration in which a plurality of electromagnetic steel plates 41a having substantially the same width in the circumferential direction are stacked. Therefore, as described above, the circumferential end surface of the equal width portion 47a is substantially the same. It is a flat surface. Thereby, the stator core 41 can be accurately positioned in the circumferential direction by bringing the equal width portion 47a into contact with the first positioning member P1. Moreover, since the 1st positioning member P1 and the stator core 41 can be made to contact stably, it can suppress that the stator core 41 moves with the pressure of resin. Therefore, by providing the stator core 41 with the equal width portion 47a, the stator core 41 having a configuration in which the electromagnetic steel plates 41a are laminated in the radial direction can be accurately arranged in the circumferential direction. Moreover, since the additional structure for performing positioning does not arise, the enlargement of the stator 40 can be suppressed.

Also, when the flange portion is composed only of the enlarged portion, it is necessary to make all the shapes of the electromagnetic steel plates constituting the stator core different. Therefore, for example, it is necessary to prepare a die for punching by pressing for each electromagnetic steel sheet, and the manufacturing cost of the stator core tends to increase. On the other hand, the plurality of electromagnetic steel plates 41a constituting the equal width portion 47a can have the same shape. Therefore, it is possible to manufacture a plurality of electromagnetic steel plates 41a constituting the equal width portion 47a by stamping with the same die. Thereby, since the flange part 41c has the equal width part 47a, the number of the mold | die which punches the electromagnetic steel plate 41a can be decreased, and the manufacturing cost of the stator core 41 can be made small.

In FIG. 8, both ends in the circumferential direction of the equal width portion 47a are in contact with the first positioning members P1 located on both sides in the circumferential direction of the equal width portion 47a. Thereby, the stator core 41 can be positioned in the circumferential direction by sandwiching the stator core 41 by the two first positioning members P1. Therefore, it is possible to suppress the stator core 41 from moving in the circumferential direction. In the present embodiment, since the equal width portion 47a is located on the radially outer side than the enlarged portion 47b, it is easy to increase the circumferential width of the equal width portion 47a. Thereby, the circumferential direction width | variety of the part pinched by the 1st positioning member P1 in the flange part 41c becomes large. Therefore, in the present embodiment, the stator core 41 can be more stably sandwiched by the first positioning member P1, and thus the stator core 41 can be further suppressed from moving in the circumferential direction. Both circumferential ends of the first positioning member P1 are in contact with the equal width portions 47a of the adjacent stator cores 41, respectively.

In the arranging step S3, the second positioning member P2 arranged in the mold D contacts the radially inner end of the stator core 41. Therefore, in the mold D, the stator core 41 is positioned in the radial direction. More specifically, the radially inner end of the flange portion 41c contacts the second positioning member P2, and the stator core 41 is positioned in the radial direction. In the arrangement step S3, the bearing holder 44 and the cover 45 are also arranged in the mold D. In the placement step S3, a positioning member that contacts the radially outer end of the stator core 41 may be provided separately from the first positioning member P1 and the second positioning member P2.

Resin molding step S4 is a step in which molten resin is poured into the mold D to form a resin portion 46 located at least partially between the stator cores 41 adjacent in the circumferential direction. In the resin molding step S4, the first recess 48a is formed by the first positioning member P1 arranged in the mold D. Therefore, the outer shape of the first recess 48a viewed in the axial direction is the same as the outer shape of the first positioning member P1 viewed in the axial direction. Thus, since the stator 40 of this embodiment is provided with the resin part 46 which has the 1st recessed part 48a, in the arrangement | positioning process S3, the above-mentioned manufacturing method which positions the stator core 41 using the 1st positioning member P1 is employ | adopted. it can. Therefore, the stator 40 in which the stator core 41 is accurately arranged along the circumferential direction is obtained.

Further, since the circumferential width of the first recess 48a increases from the radially inner side to the radially outer side, the shape of the first positioning member P1 used in the placement step S3 increases from the radially inner side to the radially outer side. It becomes a shape. Thereby, the manufacturing method which makes the equal width part 47a of the stator core 41 adjacent to the circumferential direction respectively contact the circumferential direction both ends of one 1st positioning member P1 is employable. Therefore, the number of first positioning members P1 used in the arrangement step S3 can be reduced, and the manufacturing cost of the stator 40 can be reduced.

In the placement step S3, when the first positioning member P1 and the equal width portion 47a come into contact with each other with high accuracy, the resin does not enter between the first positioning member P1 and the equal width portion 47a. Therefore, the portion of the equal width portion 47a that has been in contact with the first positioning member P1 is exposed in the first recess 48a formed in the resin molding step S4. As described above, in a case where at least a part of the equal width portion 47a is exposed in the first recess 48a, a manufacturing method in which the first positioning member P1 and the equal width portion 47a are brought into contact with each other in the placement step S3 can be employed. . As a result, the stator 40 having a better positioning accuracy of the stator core 41 can be obtained.

In addition, when the precision with which the 1st positioning member P1 and the equal width part 47a contact is comparatively low, resin may enter between the 1st positioning member P1 and the equal width part 47a slightly. In this case, the equal width portion 47a may not be exposed in the first recess 48a. However, even in this case, in the present embodiment, the stator core 41 can be positioned with sufficient accuracy by the first positioning member P1.

In the resin molding step S4, the second recess 48b is formed by the second positioning member P2 disposed in the mold D. The outer shape of the second recess 48b viewed in the axial direction is the same as the outer shape of the second positioning member P2 viewed in the axial direction. Thus, since the stator 40 of this embodiment is provided with the resin part 46 which has the 2nd recessed part 48b, in the arrangement | positioning process S3, the above-mentioned manufacturing method which positions the stator core 41 using the 2nd positioning member P2 is employ | adopted. it can. Therefore, the stator 40 in which the stator core 41 is accurately positioned in the radial direction is obtained.

In the placement step S3, when the second positioning member P2 and the stator core 41 come into contact with each other with high accuracy, the resin does not enter between the second positioning member P2 and the stator core 41. Therefore, the portion of the stator core 41 that has been in contact with the second positioning member P2 is exposed in the second recess 48b formed in the resin molding step S4. As described above, in the configuration in which at least a part of the radial inner end of the stator core 41 is exposed in the second recess 48b, the second positioning member P2 and the radial inner end of the stator core 41 are accurately contacted in the placement step S3. A manufacturing method can be adopted. As a result, the stator 40 having a better positioning accuracy of the stator core 41 can be obtained.

The present invention is not limited to the above-described embodiment, and other configurations can be adopted. In the following description, the same configurations as those described above may be omitted by appropriately attaching the same reference numerals.

The stator core 41 may have a shape like the stator core 141 shown in FIG. As shown in FIG. 9, the core columnar portion 141 b has a stepped portion 149 a that decreases in the circumferential width from the radially inner side toward the radially outer side at the radially outer end. The stepped portion 149a is a step formed by laminating the electromagnetic steel plates 141a on the radially outer side of the equal width columnar portion 49a. The circumferential width of the core columnar portion 141b in the electromagnetic steel sheet 141a is smaller than the circumferential width of the equal width columnar portion 49a. For example, when the conductive wire of the coil is wound around the core columnar portion via an insulator, the corner portion at the radially outer end of the core columnar portion interferes with the configuration in which the stepped portion 149a is not provided. Thus, there is a problem that the outer diameter of the coil becomes large. Therefore, there has been a problem that the stator is enlarged in the radial direction. On the other hand, by providing the stepped portion 149a, the conductive wire is wound along the outer shape of the core columnar portion 141b, and the bulging of the conductive wire can be suppressed. Therefore, it can suppress that the outer diameter of the coil 42 becomes large, and can suppress that the stator 40 enlarges to radial direction as a result.

The flange portion 141c has a flange step portion 149b that decreases in the circumferential width from the radially inner side toward the radially outer side at the radially outer end. The flange step portion 149b is a step formed by laminating the electromagnetic steel plates 141a on the radially outer side than the equal width portion 47a. The circumferential width of the flange portion 141c in the electromagnetic steel plate 141a is smaller than the circumferential width of the equal width portion 47a. Thus, the circumferential width of the electromagnetic steel plate 141a is smaller than the electromagnetic steel plate 41a constituting the equal width portion 47a in both the core columnar portion 141b and the flange portion 141c. In the present embodiment, the shape of the electromagnetic steel plate 141a can be made the same as any one of the electromagnetic steel plates 41a constituting the enlarged portion 47b. Therefore, it is not necessary to separately prepare a die for punching the electromagnetic steel sheet 141a by press working, and it is possible to suppress an increase in the manufacturing cost of the stator core 141.

The first recess 48a and the second recess 48b may be provided on the upper surface 40a of the stator 40, or may be provided on both the upper surface 40a and the lower surface 40b. Further, the second recess 48b may be an annular shape surrounding the central axis J. In this case, only one annular second positioning member is provided in the arrangement step S3, and each stator core 41 is positioned in the radial direction by one second positioning member.

Further, the equal width portion 47a may be provided at any position of the flange portion 41c in the radial direction. The equal width portion 47a may be located at the radially inner end of the flange portion 41c, or may be located at the radial center of the flange portion 41c. Moreover, the circumferential direction width | variety of the core columnar part 41b may be the same over the whole radial direction.

Further, although the motor 10 described above is a shaft rotation type motor in which the

rotors

31 and 32 are fixed to the shaft 20, it is not limited thereto. The motor to which the present invention is applied may be a fixed shaft type motor to which a shaft is fixed.

The above configurations can be appropriately combined within a range that does not contradict each other.

DESCRIPTION OF SYMBOLS 10 ... Motor, 20 ... Shaft, 31, 32 ... Rotor, 40 ... Stator, 41, 141 ... Stator core, 41a, 141a ... Electromagnetic steel plate, 41b, 141b ... Core columnar part, 41c, 141c ... Flange part, 41e ... Stator core recessed part , 41f ... step surface, 42 ... coil, 43 ... insulator, 46 ... resin part, 46a ... resin body part, 47a ... uniform width part, 47b ... enlarged part, 47c ... groove part, 48a ... first recess, 149a ... step part , D ... mold, Da ... bottom surface, J ... central axis, P1 ... first positioning member, P2 ... second positioning member, S1 ... stator core forming step (step S1), S2 ... coil mounting step (step S2), S3 ... Placement process (process S3), S4 ... Resin molding process (process S4)

Claims

A stator that is axially opposed to a rotor that rotates about a central axis that extends in the vertical direction and a gap,
A plurality of stator cores arranged along the circumferential direction;
A coil wound around the stator core;
An insulator located at least partially between the stator core and the coil;
A resin portion located between the stator cores at least partially adjacent in the circumferential direction;
With
The stator core has a configuration in which a plurality of electromagnetic steel plates are laminated in a radial direction,
The stator core includes a core columnar portion that extends in the axial direction and around which the coil is wound, and a plate-like flange portion that is connected to an axial end of the core columnar portion and extends in the circumferential direction,
The flange portion has an enlarged portion in which the circumferential width increases from the radially inner side toward the radially outer side, and an equal width portion having substantially the same circumferential width and extending in the radial direction,
The equal width portion is a configuration in which a plurality of the electromagnetic steel sheets having substantially the same circumferential width in the flange portion are laminated in a radial direction,
The resin part is
A resin main body located at least partially between the flanges adjacent in the circumferential direction;
A first recess that is recessed in the axial direction from the axial end surface of the resin main body and located between the equal width portions of the stator core adjacent in the circumferential direction;
Having a stator.
2. The stator according to claim 1, wherein at least part of the equal width portion is exposed in the first recess.
The stator according to claim 2, wherein a circumferential width of the first recess increases from a radially inner side toward a radially outer side.
4. The stator according to claim 3, wherein the equal-width portion is located on a radially outer side than the enlarged portion.
The electromagnetic steel sheet has a stator core recess recessed in a direction orthogonal to the radial direction,
The stator according to claim 1, wherein the stator core includes a groove portion that is configured by a plurality of the stator core concave portions and extends in a radial direction.
The resin part has a second recess that is recessed in the axial direction from the axial end surface of the resin body part,
2. The stator according to claim 1, wherein at least a part of the second recess is located on a radially inner side of a radially inner end of the stator core.
The stator according to claim 6, wherein at least a part of a radially inner end of the stator core is exposed in the second recess.
2. The stator according to claim 1, wherein the core columnar portion has a stepped portion having a circumferential width that decreases from a radially inner side toward a radially outer side at a radially outer end.
The axial end surface of the stator core has a step surface that is recessed toward the coil in the axial direction,
The stator according to claim 1, wherein a part of the resin portion is disposed on the step surface.
2. The stator according to claim 1, wherein a bottom surface of the first recess is in a position shallower than a region where the coil is disposed in the axial direction.
The stator according to any one of claims 1 to 10,
A rotor facing the stator in the axial direction through a gap;
A shaft that rotatably supports the rotor;
Comprising a motor.
A method of manufacturing a stator that is axially opposed to a rotor that rotates about a central axis that extends in the vertical direction and a gap,
A step S1 of laminating a plurality of electromagnetic steel sheets in the radial direction to form a plurality of stator cores;
A step S2 of attaching a coil to the stator core;
A step S3 of arranging a plurality of stator cores in the mold along the circumferential direction;
Step S4 of pouring molten resin into the mold and forming a resin portion located between the stator cores at least partially adjacent in the circumferential direction;
Including
The stator core includes a core columnar portion that extends in the axial direction and around which the coil is wound, and a plate-shaped flange portion that is connected to an axial end of the core columnar portion and extends in the radial direction,
The flange portion has an enlarged portion in which the circumferential width increases from the radially inner side toward the radially outer side, and an equal width portion having substantially the same circumferential width and extending in the radial direction,
The equal width portion is a configuration in which a plurality of the electromagnetic steel sheets having substantially the same circumferential width in the flange portion are laminated in a radial direction,
In the step S3, a stator manufacturing method in which the equal width portion is brought into contact with a first positioning member disposed in the mold to position the stator core in the circumferential direction.
The stator manufacturing method according to claim 12, wherein in step S <b> 3, a radial inner end of the stator core is brought into contact with a second positioning member disposed in the mold to position the stator core in the radial direction. .