JP7488468B2 - Electromagnetic Device - Google Patents

Description

This disclosure relates to electromagnetic devices.

Conventionally, there is known an electromagnetic device (e.g., a claw pole motor or a thrust magnetic bearing) that includes a coil formed by winding a conducting wire and a core arranged facing the outside of both ends of the coil in the winding axis direction (see Patent Documents 1 and 2).

Patent Publication No. 2013-158072 JP 2019-173823 A

The thermal energy generated by the copper loss in the coil is transferred to the heat dissipation member through the insulating material (e.g., insulating paper, insulator, resin mold, etc.) between the coil and the core, and through the core, thereby cooling the coil.

However, for example, when the coil is made of a round wire and the insulating member is provided separately from the coil, the contact area between the coil and the insulating member may be relatively small, and the thermal resistance between the coil and the insulating member may be relatively high. As a result, the thermal conductivity between the coil and the insulating member may be relatively low, and the cooling performance of the coil may be relatively low. Furthermore, for example, when the winding axis of the coil is arranged along a substantially vertical direction, the weight of the coil may cause a gap to be generated between the upper end of the coil and the insulating member, which may further reduce the thermal conductivity between the coil and the insulating member and further reduce the cooling performance of the coil. Therefore, there is room for improvement in terms of the cooling performance of the coil.

The present disclosure aims to provide a technology for improving the cooling performance of a coil in an electromagnetic device that includes a core that is arranged facing the outside of both ends of the coil in the winding axis direction.

In one embodiment of the present disclosure,
A coil formed by winding a conductor;
a core disposed outside both ends of the coil in a winding axis direction so as to face each other;
an elastic force generating unit that generates an elastic force so as to expand the conductor wire at both ends of the coil in the winding axis direction outward in the winding axis direction,
An electromagnetic device is provided.

According to this embodiment, the conductor wire at both ends of the coil in the winding axis direction is biased toward the core by elastic force. Therefore, for example, when the coil is made of round wire and an insulating member is provided separately from the coil, the degree of contact (contact area) between the coil and the insulating member can be relatively increased, and the thermal resistance between the coil and the insulating member can be relatively reduced. Furthermore, for example, when the winding axis of the coil is arranged along a substantially vertical direction, the gap between the upper end of the coil and the insulating member can be eliminated, and the conductor wire at the upper end of the coil can come into contact with the insulating member. This improves the cooling performance of the coil.

In the above embodiment,
an insulating portion for insulating the coil from the core;
The insulating portion may be configured to be able to move in accordance with outward expansion in the winding axis direction of the conductor wire at both ends of the coil in the winding axis direction.

In the above embodiment,
the elastic force generating portion is the coil,
The coil may generate the elastic force.

In the above embodiment,
The elastic force generating portion may be an elastic member that is arranged between the conductor wires at both ends of the coil in the winding axis direction and generates the elastic force that urges the conductor wires at both ends of the coil in the winding axis direction outward in the winding axis direction.

In the above embodiment,
At least a portion of the conductor of the coil may be formed into a coil spring shape.

In the above embodiment,
The coil may be configured so that a portion of the conductor wire has a convex shape in the winding axis direction when viewed from a direction perpendicular to the winding axis.

In the above embodiment,
The elastic force may be generated by a lead wire of the coil.

In the above embodiment,
The coil includes a first coil and a second coil aligned in the winding axis direction,
The elastic member may be provided between the first coil and the second coil.

In the above embodiment,
The conductor wire may be a rectangular wire or a flat wire.

According to the above-described embodiment, in an electromagnetic device including a core arranged facing the outside of both ends of a coil in the winding axis direction, it is possible to improve the cooling performance of the coil.

FIG. 1 is a perspective view showing an example of a claw pole motor. FIG. 2 is a perspective view showing an example of a stator. FIG. 1 is a vertical cross-sectional view showing an example of a claw pole motor. FIG. 2 is an exploded view showing an example of the configuration of a stator unit. FIG. 11 is an exploded view showing another example of the configuration of the stator unit. FIG. 2 is a diagram showing an example of a thermal circuit for cooling a coil. FIG. 11 is a vertical cross-sectional view showing the structure of a claw pole motor (stator) according to a comparative example. FIG. 11 is a diagram showing an example of a thermal circuit between a coil and a stator core of a claw pole motor according to a comparative example. 1 is a vertical cross-sectional view showing a structure of a claw pole motor (stator) according to an embodiment of the present invention. FIG. 2 is a diagram showing an example of a thermal circuit between a coil and a stator core of a claw pole motor according to an embodiment. 1A is a diagram showing a schematic diagram of a first example of a structure for generating an elastic force that expands the conductor wires at both axial ends of a coil outward in the axial direction. FIG. 13 is a diagram showing a schematic diagram of a second example of a structure for generating an elastic force that expands the conductor wires at both axial ends of the coil outward in the axial direction. FIG. 13 is a diagram showing a schematic diagram of a third example of a structure for generating an elastic force that expands the conductor wires at both axial ends of the coil outward in the axial direction. FIG. 13 is a diagram showing a schematic diagram of a fourth example of a structure for generating an elastic force that expands the conductor wires at both axial ends of the coil outward in the axial direction. FIG. 13 is a diagram showing a schematic diagram of a fifth example of a structure for generating an elastic force that expands the conductor wires at both axial ends of the coil outward in the axial direction. FIG. 13 is a diagram showing a schematic diagram of a sixth example of a structure for generating an elastic force that expands the conductor wires at both axial ends of the coil outward in the axial direction. FIG. 13 is a diagram showing a schematic diagram of a seventh example of a structure for generating an elastic force that expands the conductor wires at both axial ends of the coil outward in the axial direction. FIG. 13 is a diagram showing a schematic diagram of an eighth example of a structure for generating an elastic force that expands the conductor wires at both axial ends of the coil outward in the axial direction. FIG. 1 is a diagram showing a schematic diagram of a first example of an insulating portion structure that does not hinder the axial outward expansion of the conductor wires at both axial ends of the coil. FIG. 13 is a diagram showing a schematic diagram of a second example of an insulating portion structure that does not hinder the axial outward expansion of the conductor wires at both axial ends of the coil. FIG. 13 is a diagram showing a schematic diagram of a third example of an insulating portion structure that does not hinder the axial outward expansion of the conductor wires at both axial ends of the coil. FIG. 13 is a diagram showing a schematic diagram of a fourth example of an insulating portion structure that does not hinder the axial outward expansion of the conductor wires at both axial ends of the coil. FIG. 13 is a diagram showing a schematic diagram of a fifth example of an insulating structure that does not hinder the axial outward expansion of the conductor wires at both axial ends of the coil. FIG. 13 is a diagram showing a schematic diagram of a sixth example of an insulating structure that does not hinder the axial outward expansion of the conductor wires at both axial ends of the coil. FIG. 13 is a diagram showing a schematic diagram of a seventh example of an insulating structure that does not hinder the axial outward expansion of the conductor wires at both axial ends of the coil. FIG. 13 is a diagram showing a schematic diagram of an eighth example of an insulating structure that does not hinder the axial outward expansion of the conductor wires at both axial ends of the coil. FIG. A diagram showing a ninth example of an insulating portion structure that does not hinder the axial outward expansion of the conductor wire at both axial ends of the coil. A diagram showing a schematic diagram of a tenth example of an insulating structure that does not hinder the axial outward expansion of the conductor wire at both axial ends of the coil.

The following describes the embodiment with reference to the drawings.

[Configuration of Claw Pole Motor]
First, a claw pole motor 1 according to the present embodiment will be described with reference to FIGS.

Figure 1 is a perspective view showing an example of a claw pole motor 1 according to this embodiment. Figure 2 is a perspective view showing an example of a stator 20 of a claw pole motor 1 according to this embodiment. Specifically, Figure 2 is a diagram in which the rotor 10 (rotor core 11, permanent magnet 12, and rotating shaft member 13) is omitted from Figure 1. Figure 3 is a vertical cross-sectional view showing an example of a claw pole motor 1. Figures 4 and 5 are exploded views showing an example and another example of the configuration of a stator unit 21 according to this embodiment.

For simplicity, the connecting member 14, which will be described later, is omitted in FIG. 1. For simplicity, the claw magnetic pole portion 211B2 and the insulating portion 213 are omitted in FIG. 3. In FIG. 3, the movement of the thermal energy generated in the coil 212 is shown generally by dashed arrows.

As shown in FIG. 1, the claw pole motor (also called a "claw pole electric motor") 1 is an outer rotor type synchronous motor (SM) that is driven by a multi-phase (three-phase in this example) armature current. The claw pole motor 1 is mounted, for example, in a compressor or fan of an air conditioner.

As shown in Figures 1 to 3, the claw pole motor 1 includes a rotor 10, a stator 20, and a fixed member 30.

As shown in FIG. 1, the rotor 10 is disposed radially outward of the stator 20 (hereinafter simply referred to as the "radial direction") of the claw-pole motor 1 and is configured to be rotatable around the rotation axis AX. The rotor 10 is a permanent magnet field and includes a rotor core 11, a plurality of permanent magnets 12 (20 in this example), and a rotating shaft member 13.

The rotor core (also called "rotor core") 11 has, for example, a substantially cylindrical shape, and is arranged so that the rotation axis AX of the claw pole motor 1 and the axis of the cylindrical shape are substantially aligned. The word "substantially" is intended to allow for, for example, manufacturing errors, and is used with the same intention below. The rotor core 11 has a length substantially equal to that of the stator 20 in the axial direction of the claw pole motor 1 (hereinafter simply referred to as the "axial direction"). The rotor core 11 is formed of, for example, a soft magnetic material such as an electromagnetic steel plate, cast iron, or a powder magnetic core. The rotor core 11 is, for example, as shown in FIG. 1, composed of a single member in the axial direction. The rotor core 11 may also be composed of, for example, multiple rotor cores stacked in the axial direction (for example, three rotor cores corresponding to each of the stator units 21A to 21C described later).

The multiple permanent magnets 12 generate a magnetic field that interlinks with the stator 20, which acts as an armature.

As shown in FIG. 2, multiple permanent magnets 12 (20 in this example) are arranged at approximately equal intervals in the circumferential direction on the inner circumferential surface of the rotor core 11. In other words, the claw pole motor 1 may be a surface permanent magnet (SPM) type.

The permanent magnets 12 may be arranged, for example, embedded in the rotor core 11 and spaced at approximately equal intervals in the circumferential direction. In other words, the claw pole motor 1 may be an interior permanent magnet (IPM) type.

The multiple permanent magnets 12 are each formed so as to be present between approximately one end and approximately the other end in the axial direction of the rotor core 11. The permanent magnets 12 are, for example, neodymium sintered magnets or ferrite magnets.

Each of the multiple permanent magnets 12 is magnetized with different magnetic poles at both radial ends. Furthermore, two of the multiple permanent magnets 12 that are adjacent in the circumferential direction are magnetized with different magnetic poles on the radially inner side facing the stator 20. Therefore, on the radially outer side of the stator 20, permanent magnets 12 magnetized with a north pole on the radially inner side and permanent magnets 12 magnetized with a south pole on the radially inner side are alternately arranged in the circumferential direction.

Each of the multiple permanent magnets 12 may be composed of a single magnet member in the axial direction, or may be composed of multiple magnet members (e.g., three, corresponding to the number of stacked rotor core 11 members) divided in the axial direction. In this case, the multiple magnet members constituting the permanent magnet 12 divided in the axial direction are all magnetized with the same magnetic pole on the radially inner side facing the stator 20.

The multiple permanent magnets 12 arranged in the circumferential direction may be replaced with permanent magnets made of a single material in the circumferential direction, such as an annular ring magnet or a plastic magnet in which different magnetic poles are alternately magnetized in the circumferential direction. In this case, the permanent magnet made of a single material in the circumferential direction may also be made of a single material in the axial direction, and may be made of a single material as a whole. Furthermore, the permanent magnet made of a single material in the circumferential direction may be divided into multiple materials in the axial direction, as in the case of multiple permanent magnets 12. Furthermore, when a plastic magnet made of a single material in the circumferential direction is used, the rotor core 11 may be omitted.

The rotating shaft member 13 has, for example, a substantially cylindrical shape, and is arranged so that the rotation axis AX of the claw pole motor 1 and the axis of the cylindrical shape are substantially aligned. The rotating shaft member 13 is rotatably supported, for example, by bearings 25, 26 (see FIG. 3, etc.) provided at both axial ends of the insertion member 24. As described below, the insertion member 24 is fixed to the fixed member 30. This allows the rotating shaft member 13 to rotate around the rotation axis AX relative to the fixed member 30. The rotating shaft member 13 is connected to the rotor core 11 via a connecting member 14 (see FIG. 3, etc.) at the end opposite the end of the claw pole motor 1 on the fixed member 30 side in the axial direction (hereinafter, for convenience, "the tip end of the claw pole motor 1").

The connecting member 14 may have, for example, a generally disk shape that closes the open end of the generally cylindrical shape of the rotor core 11. This allows the rotor core 11 and the multiple permanent magnets 12 fixed to the inner peripheral surface of the rotor core 11 to rotate around the rotation axis AX of the claw-pole motor 1 relative to the fixed member 30 in accordance with the rotation of the rotating shaft member 13.

In addition, instead of the fixed member 30, the rotating shaft member 13 may be rotatably supported on a housing (not shown) via a bearing or the like at the tip end side of the claw pole motor 1. In this case, the insertion hole 24H (see FIG. 3) through which the rotating shaft member 13 passes is omitted in the insertion member 24.

As shown in Figures 2 and 3, the stator (also referred to as "stator") 20 is disposed radially inside the rotor 10 (rotor core 11 and permanent magnets 12). The stator 20 includes a plurality (three in this example) of claw-pole type stator units (hereinafter simply referred to as "stator units") 21, a plurality (two in this example) of interphase members 22, end members 23, and insertion members 24.

As shown in Figures 4 and 5, the stator unit 21 includes a pair of stator cores 211 and a coil 212. The stator unit 21 also includes an insulating portion 213 (see Figure 9).

A pair of stator cores (also called "stator cores") 211 are arranged to surround the coils 212. The stator cores 211 are formed of a soft magnetic material such as a powder magnetic core. The stator cores 211 include a yoke portion 211A, a plurality of claw poles (also called "claw poles") 211B, a yoke portion 211C, and an insertion hole 211D.

The yoke portion 211A has a generally circular ring shape when viewed in the axial direction and has a predetermined thickness in the axial direction.

The multiple claw poles 211B are arranged at equal intervals in the circumferential direction on the outer circumferential surface of the yoke portion 211A, and each protrudes radially outward from the outer circumferential surface of the yoke portion 211A. The claw poles 211B include claw pole portions 211B1.

The claw magnetic pole portion 211B1 has a predetermined width and protrudes a predetermined length from the outer peripheral surface of the yoke portion 211A.

The claw pole 211B further includes a claw pole portion 211B2. This ensures a relatively wide facing area between the rotor 10 and the pole surface of the claw pole 211B magnetized by the armature current of the coil 212. This allows the output torque of the claw pole motor 1 to be relatively increased, improving the output of the claw pole motor 1.

The claw magnetic pole portion 211B2 protrudes from the tip of the claw magnetic pole portion 211B1 toward the other of the pair of stator cores 211 by extending a predetermined length in the axial direction. For example, as shown in FIG. 4, the claw magnetic pole portion 211B2 may have a constant width regardless of the distance from the claw magnetic pole portion 211B1. Also, for example, as shown in FIG. 5, the claw magnetic pole portion 211B2 may have a tapered shape in which the width narrows as it moves away from the claw magnetic pole portion 211B1 in the axial direction.

The claw magnetic pole portion 211B2 may be omitted.

The yoke portion 211C is configured such that the portion near the inner circumferential surface of the yoke portion 211A protrudes a predetermined amount toward the other of the pair of stator cores 211, and has, for example, a circular ring shape with a smaller outer diameter than the yoke portion 211A when viewed in the axial direction. As a result, the pair of stator cores 211 abut against each other at the tips of the yoke portions 211C, and a space for accommodating the coil 212 is generated between the pair of yoke portions 211A and claw poles 211B (claw pole portions 211B1) corresponding to the pair of stator cores 211.

The insertion member 24 is inserted into the insertion hole 211D. The insertion hole 211D is formed by the inner circumferential surfaces of the yoke portion 211A and the yoke portion 211C.

The coil (also called "winding") 212 is configured by winding a conductor in an annular shape in the axial direction, with the axial center of the stator 20 (i.e., the rotation axis AX of the claw pole motor 1) as the approximate center. The conductor of the coil 212 may be wound, for example, in multiple layers in the axial direction, multiple rows in the radial direction, or multiple layers in the axial direction and multiple rows in the radial direction. The conductor of the coil 212 may be, for example, a round wire with a circular cross section. The conductor of the coil 212 may be, for example, a square wire or a rectangular wire with a rectangular cross section. When the coils 212 of multiple phases (three phases in this example) are connected to each other by Y connection (star connection), one end of the coil 212 is electrically connected to an external terminal, and the other end is electrically connected to a neutral point. Also, for example, when the coils 212 of multiple phases are connected to each other in a Δ connection (delta connection), one end of the coil 212 is electrically connected to one external terminal (external terminal of the same phase) of the claw-pole motor 1, and the other end is electrically connected to another external terminal (external terminal of a different phase) of the claw-pole motor 1. The coil 212 is disposed between the pair of stator cores 211 (yoke portions 211A) in the axial direction. The coil 212 is wound so that its inner periphery is radially outward of the yoke portions 211C of the pair of stator cores 211.

The insulating portion 213 is disposed between the stator core 211 and the conductor of the coil 212, and electrically insulates the conductor of the stator core 211 from the conductor of the coil 212. The insulating portion 213 is, for example, an insulating paper, a resin-molded insulator, silicone rubber, a resin mold for the stator core 211 or the coil 212, or the like, disposed between the stator core 211 and the coil 212. The insulating portion 213 may also be, for example, a resin insulating coating provided on the surface of the conductor of the coil 212.

As shown in FIG. 2, the pair of stator cores 211 are assembled so that the claw poles 211B of one stator core 211 and the claw poles 211B of the other stator core 211 are arranged alternately in the circumferential direction. When an armature current flows through the annular coil 212, the claw poles 211B formed on one of the pair of stator cores 211 and the claw poles 211B formed on the other are magnetized to different magnetic poles. As a result, in the pair of stator cores 211, one claw pole 211B protruding from one stator core 211 is adjacent to the other claw pole 211 in the circumferential direction and has a different magnetic pole from the other claw pole 211B protruding from the other stator core 211. Therefore, due to the armature current flowing through the coil 212, the N-pole claw poles 211B and the S-pole claw poles 211B are arranged alternately in the circumferential direction of the pair of stator cores 211.

As shown in Figures 2 and 3, multiple stator units 21 are stacked in the axial direction.

The multiple stator units 21 include stator units 21 for multiple phases (three phases in this example). Specifically, the multiple stator units 21 include stator unit 21A corresponding to the U phase, stator unit 21B corresponding to the V phase, and stator unit 21C corresponding to the W phase. The multiple stator units 21 are stacked from the tip of the claw pole motor 1 in the order of stator unit 21A corresponding to the U phase, stator unit 21B corresponding to the V phase, and stator unit 21C corresponding to the W phase. The stator units 21A to 21C are arranged such that their circumferential positions differ from each other by 120° in electrical angle.

The claw pole motor 1 may be driven by a two-phase armature current, or by a four or more phase armature current.

The inter-phase member 22 is provided between stator units 21 of different phases that are adjacent in the axial direction. The inter-phase member 22 is, for example, a non-magnetic material. This ensures a predetermined distance between the two stator units 21 of different phases, and suppresses magnetic flux leakage between the two stator units 21 of different phases. The inter-phase member 22 includes a UV inter-phase member 22A and a VW inter-phase member 22B.

The UV interphase member 22A is provided between the U-phase stator unit 21A and the V-phase stator unit 21B, which are adjacent in the axial direction. The UV interphase member 22A has, for example, a substantially cylindrical shape (substantially disc shape) with a predetermined thickness, and an insertion hole through which the insertion member 24 is inserted is formed in the center. The same may be true for the VW interphase member 22B below.

The VW interphase member 22B is provided between the V-phase stator unit 21B and the W-phase stator unit 21C, which are adjacent in the axial direction.

The end member 23 is provided at the end of the stacked stator units 21 on the tip side of the claw pole motor 1. Specifically, the end member 23 is provided so as to contact the end face of the stator unit 21A opposite to the side facing the stator unit 21B in the axial direction. The end member 23 has, for example, a substantially cylindrical shape (substantially disc shape) with a predetermined thickness, and an insertion hole through which the insertion member 24 is inserted is formed in the center. The end member 23 is, for example, a non-magnetic material. This makes it possible to suppress magnetic flux leakage from the stator unit 21A (specifically, the stator core 211 on the tip side of the claw pole motor 1).

In addition, end members 23 may be provided at the ends of the multiple stator units 21 on the base end side (i.e., the fixed member 30 side) of the claw pole motor 1. In this case, the end member 23 on the base end side of the claw pole motor 1 is disposed between the stator unit 21C and the fixed member 30.

The inserting member 24 is inserted through the end member 23, the stator unit 21A, the UV interphase member 22A, the stator unit 21B, the VW interphase member 22B, and the stator unit 21C in order from the tip side of the claw pole motor 1, and the tip is fixed to the fixed member 30. The inserting member 24 has, for example, a male threaded portion at the tip, and is fixed to the fixed member 30 by being fastened to the corresponding female threaded portion of the fixed member 30. The inserting member 24 has, for example, a substantially cylindrical shape, and the rotating shaft member 13 is rotatably arranged in the insertion hole 24H realized by the inner circumferential surface. The inserting member 24 has, at the tip side of the claw pole motor 1, a head having an outer diameter relatively larger than the inner diameter of the insertion hole 211D of the stator unit 21. As a result, for example, by fastening the inserting member 24 to a certain extent to the fixed member 30, a force can be applied from the head to the end member 23 in the axial direction toward the fixed member 30. Therefore, multiple stator units 21 (stator units 21A-21C) and interphase members 22 (UV interphase member 22A, VW interphase member 22B) can be fixed to the fixed member 30 by sandwiching them between the end members 23 and the fixed member 30. Powder cores have relatively low strength against tensile stress, but relatively high strength against compressive stress. Therefore, they can be fixed to the stator units 21A-21C by compressive stress acting on the stator core 211 formed from the powder core.

In addition, if it is possible to fix multiple stator units 21 and interphase members 22 to the fixed member 30 by sandwiching them between the end member 23 and the fixed member 30 using a member other than the insertion member 24, the insertion member 24 may be integrated with the fixed member 30 and configured as a single member.

The fixing member 30 has, for example, a generally circular disk shape with an outer diameter larger than that of the rotor 10 (rotor core 11) when viewed in the axial direction. As described above, the rotor 10 is rotatably supported by the fixing member 30 via the insertion member 24, and the stator 20 is fixed thereto.

The fixing member 30 may have a step shape, fin shape, pin shape, etc., in areas other than the area facing the stator 20 in the axial direction. This allows the fixing member 30 to have a relatively large surface area, which can promote heat dissipation to the outside air. This further suppresses the temperature rise of the fixing member 30 when the heat generated in the coil 212 is conducted, and ensures that the heat generated in the coil 212 is transferred to the fixing member 30, promoting the cooling of the coil 212.

[Outline of coil cooling structure]
Next, a structure for cooling the coil 212 in the claw pole motor 1 will be described with reference to FIGS.

<Thermal circuit for cooling the coil>
6 is a diagram showing an example of a thermal circuit related to cooling of the coil 212. Specifically, this is a specific example of a thermal circuit in which heat from the coil 212 is conducted to the fixing member 30 and then released to the outside air OA.

As shown in FIG. 6, the thermal energy generated in the coil 212 of the stator unit 21A is conducted in the axial direction through the insulating portion 213 of the stator unit 21A and the stator core 211 (yoke portion 211A and claw pole 211B) in that order. The thermal energy of the stator core 211 of the stator unit 21A is then transferred through the UV interphase member 22A, the stator core 211 of the stator unit 21B, the VW interphase member 22B, the stator core 211 of the stator unit 21C, and the fixing member 30 in that order, and is dissipated into the outside air OA.

Similarly, the thermal energy generated in the coil 212 of the stator unit 21B is conducted in the axial direction through the insulating part 213 of the stator unit 21B and the stator core 211 (the yoke part 211A and the claw pole 211B) in that order. The thermal energy of the stator core 211 of the stator unit 21B is then transferred through the VW interphase member 22B, the stator core 211 of the stator unit 21C, and the fixing member 30 in that order, and is dissipated into the outside air OA.

Similarly, the thermal energy generated in the coil 212 of the stator unit 21C is conducted in the axial direction through the insulating portion 213 of the stator unit 21C and the stator core 211 (the yoke portion 211A and the claw pole 211B). Then, the thermal energy of the stator core 211 of the stator unit 21C is directly transferred to the fixed member 30 (in the case where an end member 23 is present between the stator core 211 and the fixed member 30, the end member 23 and the fixed member 30 are transferred in that order), and is dissipated into the outside air OA.

As shown in FIG. 6, there is thermal resistance between the components according to the thermal conductivity of each component and the degree of contact between the components, and the smaller the thermal resistance, the higher the cooling performance of the coil 212 becomes. The thermal resistance decreases as the thermal conductivity of each component decreases, and decreases as the degree of contact between the components (e.g., the contact area) increases.

<Structure for cooling coils in a claw-pole motor according to a comparative example>
Fig. 7 is a vertical cross-sectional view showing an example of the structure of a claw-pole motor 1com (stator 20com) according to a comparative example. Fig. 8 is a diagram showing an example of a thermal circuit between a coil 212com and a stator core 211 of the claw-pole motor 1com according to the comparative example.

The claw pole motor 1com of the comparative example is the same as the claw pole motor 1 of the present embodiment in that the coil 212 and the insulating portion 213 of the claw pole motor 1 of the present embodiment are replaced with the coil 212com and the insulating portion 213com. Therefore, in FIG. 7, the components of the claw pole motor 1com other than the coil 212com and the insulating portion 213com are given the same reference numerals as the claw pole motor 1 of the present embodiment.

As shown in FIG. 7, in the claw pole motor 1com according to the comparative example, insulating parts 213com are arranged between the coil 212com and the stator core 211 (yoke part 211A and claw pole 211B) at both ends of the coil 212com in the axial direction (vertical direction).

In addition, for example, the conductor wire included in the coil 212com may be arranged lower in the space between the upper and lower insulating parts 213com, with the gap being filled by its own weight. This may result in a very small degree of contact (contact area) between the conductor wire at the upper end of the coil 212com and the insulating part 213com, or a gap GP1 may be created as shown in FIG. 7. As a result, the thermal resistance between the coil 212com and the insulating part 213com facing the upper end of the coil 212com may become very large, and it may become impossible to conduct almost any thermal energy from the coil 212com to the insulating part 213com facing the upper end of the coil 212com.

For example, as shown in FIG. 7, the coil 212com may be formed by winding a round wire. Therefore, the degree of contact (contact area) between the conductor at the lower end of the coil 212com and the insulating part 213com may be relatively small. As a result, the thermal resistance R1c between the coil 212com and the insulating part 213com facing the lower end of the coil 212com may be relatively large.

For example, when the stator core 211 is made of a powder magnetic core, the surfaces of the yoke portion 211A and the claw pole 211B are rough, so that a gap GP2 may occur between the claw pole 211B and the insulating portion 213com, as shown in FIG. 7. As a result, the thermal resistance R2c between the insulating portion 213com and the stator core 211 may become relatively large.

As such, in the claw pole motor 1com according to the comparative example, it is highly likely that the thermal energy of the coil 212com is hardly conducted to the insulating part 213com that faces the upper end part of the coil 212com. Therefore, as shown in FIG. 8, in the claw pole motor 1com according to the comparative example, it is highly likely that only one path can be used to transmit the thermal energy of the coil 212com to the stator core 211 through the insulating part 213com that faces the lower end part of the coil 212com. In this case, assuming the heat generation amount Q of the coil 212com, the temperature difference ΔTc between the coil 212com and the stator core 211 is expressed by the following formula (1).

As described above, the thermal resistances R1c and R2c are relatively large, which makes it difficult for heat to be conducted from the coil 212com to the insulating section 213com and from the insulating section 213com to the stator core 211, and the cooling performance of the coil 212com may become relatively low. Therefore, in the claw pole motor 1com according to the comparative example, the temperature difference ΔTc between the coil 212com and the stator core 211 becomes a relatively large value, and the temperature of the coil 212com may become relatively high.

<Structure for cooling coils in claw pole motor according to embodiment>
Fig. 9 is a vertical cross-sectional view showing the structure of the claw pole motor 1 (stator 20) according to this embodiment. Fig. 10 is a diagram showing an example of a thermal circuit between the coil 212 and the stator core 211 of the claw pole motor 1 according to this embodiment.

As shown in FIG. 9, the claw pole motor 1 according to this embodiment is configured to generate an elastic force EF that expands the conductors at both axial ends of the coil 212 outward in the axial direction (i.e., the upper end upward and the lower end downward).

As a result, the conductor at the lower end of the coil 212 is pressed against the insulating part 213 that faces the lower end of the coil 212. Therefore, the degree of contact (contact area) between the conductor at the lower end of the coil 212 and the insulating part 213 that faces the lower end of the coil 212 becomes relatively large. Therefore, the thermal resistance R1 between the coil 212 and the insulating part 213 that faces the lower end of the coil 212 becomes smaller than the thermal resistance R1c between the coil 212com of the claw pole motor 1com according to the comparative example and the insulating part 213 that faces the lower end of the coil 212com.

In addition, the conductor at the upper end of the coil 212 can contact the insulating part 213 that faces the upper end of the coil 212 and is pressed against the insulating part 213. Therefore, heat conduction from the conductor at the upper end of the coil 212 to the insulating part 213 that faces the upper end of the coil 212 can be reliably achieved, and the thermal resistance therebetween is approximately equal to the thermal resistance R1 between the coil 212 and the insulating part 213 that faces the lower end of the coil 212.

As shown in FIG. 9, the claw pole motor 1 of this embodiment is configured so that the insulating portion 213 does not impede the axial outward expansion of both axial ends of the coil 212 (i.e., above the upper end and below the lower end) due to the elastic force EF. In this example, the claw pole motor 1 is configured so that the insulating portion 213 can move in accordance with the axial outward expansion of both axial ends of the coil 212 due to the elastic force EF.

As a result, the insulating parts 213 facing the upper and lower ends of the coil 212 move upward and downward due to the force acting from the upper and lower ends of the coil 212 in conjunction with the elastic force EF, and are pressed against the yoke part 211A and the claw pole 211B. Therefore, the degree of contact (contact area) between the insulating parts 213 facing the upper and lower ends of the coil 212 and the yoke part 211A and the claw pole 211B becomes relatively large. Therefore, the thermal resistance R2 between the insulating parts 213 and the stator core 211 becomes smaller than the thermal resistance R2c between the insulating parts 213com and the stator core 211 of the claw pole motor 1com according to the comparative example.

In this way, in the claw pole motor 1 according to this embodiment, the thermal energy of the coil 212 is reliably conducted to the insulating parts 213 that face both axial ends of the coil 212. Therefore, as shown in FIG. 10, in the claw pole motor 1 according to this embodiment, the thermal energy of the coil 212 can be conducted to the stator core 211 in parallel through two paths via the insulating parts 213 that face both axial ends of the coil 212. In this case, assuming the heat generation amount Q of the coil 212, the temperature difference ΔT between the coil 212 and the stator core 211 is expressed by the following equation (2).

Here, as described above, the relationship between the thermal resistances R1, R2 and the thermal resistances R1c, R2c is expressed by the following equations (3) and (4).

Therefore, when the same heat generation amount Q is generated in the coils 212 and 212com, the relationship of the following formula (5) holds between the temperature difference ΔT between the coil 212 and the stator core 211 in this embodiment and the temperature difference ΔTc between the coil 212com and the stator core 211 in the comparative example.

Therefore, the temperature of the coil 212 in this embodiment is definitely lower than the temperature of the coil 212com in the comparative example.

In this way, in this embodiment, the claw pole motor 1 generates an elastic force that expands the conductor wire at both ends of the axial direction (an example of the winding axis direction) of the coil 212 outward in the axial direction.

As a result, the conductors at both ends of the axial direction of the coil 212 are urged toward the stator core 211 by elastic force. Therefore, for example, when the coil 212 is made of a round wire and an insulating part is provided separately from the coil 212, the degree of contact (contact area) between the coil 212 and the insulating part can be relatively increased, and the thermal resistance between the coil 212 and the insulating part 213 can be relatively reduced. Furthermore, for example, when the winding axis of the coil 212 is arranged along a substantially vertical direction, the gap between the upper end of the coil 212 and the insulating part 213 can be eliminated, and the conductors at the upper end of the coil 212 can be brought into contact with the insulating part 213. Furthermore, when a stator core 211 with a rough surface, such as a powder magnetic core, is used, for example, the degree of contact (contact area) between the insulating part 213 urged via the coil 212 and the stator core 211 can be relatively increased, and the thermal resistance between the insulating part 213 and the stator core 211 can be relatively reduced. This improves the cooling performance of the coil 212.

In addition, the coil 212 is fixed between the pair of stator cores 211 by an elastic force acting axially outward on the conductor wire at both axial ends of the coil 212. This makes it possible to suppress wear on the conductor wire surface of the coil 212 due to micro-vibrations, etc.

In addition, in this embodiment, the insulating portion 213 may be configured so as not to impede the axial outward expansion of the conductor wires at both axial ends of the coil 212. For example, the insulating portion 213 may be configured so as to be able to move in accordance with the axial outward expansion of the conductor wires at both axial ends of the coil 212.

This allows the degree of contact (contact area) between the insulating portion 213 and the stator core 211 to be relatively increased in accordance with the axial outward expansion of the conductors at both ends of the coil 212. This makes it possible to relatively reduce the thermal resistance between the insulating portion 213 and the stator core 211, further improving the cooling performance of the coil 212.

In addition, when at least a part of the insulating section 213 includes an insulator, it may be necessary to provide a certain clearance between the insulator-composed part of the insulating section 213 and the stator core 211 in order to prevent creep deformation during thermal expansion or contraction of the resin. This may cause rattling of the insulating section 213.

In contrast, in this embodiment, even if creep deformation occurs in the resin of the insulating part 213 due to the action of the elastic force EF, the conductors at both ends of the coil 212 in the axial direction can change position to follow the deformation. This makes it possible to prevent the insulator serving as the insulating part 213 from rattling, and also to fix the insulating part 213.

In addition, in this embodiment, the coil 212 may be constructed by winding a square wire or a rectangular wire as described above.

This increases the degree of contact (contact area) between the conductor of the coil 212 and the insulating portion 213, further improving the cooling performance of the coil 212.

In addition, in this embodiment, silicone grease or the like may be applied between the insulating portion 213 and the coil 212, and between the stator core 211 and the insulating portion 213.

This further improves the degree of contact between the conductor of the coil 212 and the insulating portion 213, and between the stator core 211 and the insulating portion 213, thereby further improving the cooling performance of the coil 212.

[Details of the structure regarding cooling of the coil]
Next, the structure relating to cooling of the coil will be described in detail with reference to FIGS.

<Structure that generates elastic force>
11 to 18 are diagrams that show first to eighth examples of a structure that generates an elastic force that expands the conductor wires at both axial ends of the coil 212 outward in the axial direction.

Note that for simplicity, the claw magnetic pole portion 211B2 and insulating portion 213 are omitted from Figures 15 to 17.

As shown in FIG. 11, in this example (first example), the coil 212 (one example of an elastic force generating section) is processed so that the conductor has a coil spring shape as a whole. The coil 212 is also configured so that its natural axial length Lco is longer than the distance Dcc between the pair of stator cores 211 of the stator unit 21 (hereinafter, "core distance"). As a result, the coil 212 is accommodated between the pair of stator cores 211 in the axial direction, and is thus in a state in which the coil 212 as a whole is contracted in the axial direction to be shorter than the natural length Lco. Therefore, the coil 212 can generate an elastic force that expands the conductor at both ends of the coil 212 itself in the axial direction outward in the axial direction.

Also, as shown in FIG. 12, in this example (second example), the coil 212 (an example of an elastic force generating section) includes a coil spring section 212a in which the conductor wire is processed into a coil spring shape in a portion between both ends in the axial direction. Also, as in the first example described above, the coil 212 is configured so that the natural length Lco in the axial direction is longer than the core distance Dcc. As a result, the coil 212 is accommodated between a pair of stator cores 211 in the axial direction, so that the coil spring section 212a is in a contracted state in the axial direction, and the entire length is shorter than the natural length Lco. Therefore, the coil 212 can generate an elastic force that expands the conductor wire at both ends in the axial direction outward in the axial direction due to the action of the coil spring section 212a.

Also, as shown in FIG. 13, in this example (third example), the coil 212 (an example of an elastic force generating part) is processed so that the conductor has a convex shape in the axial direction when viewed perpendicular to the axial direction in a part between both ends of the coil 212 in the axial direction. Specifically, the coil 212 includes a wave washer part 212b processed so that the conductor has a wave shape when viewed perpendicular to the axial direction, that is, a wave washer (also called a "wave washer") shape in a part between both ends of the coil 212 in the axial direction. Also, as in the above-mentioned first example, the coil 212 is configured so that the natural length Lco in the axial direction is longer than the core distance Dcc. As a result, the coil 212 is accommodated between a pair of stator cores 211 in the axial direction, so that the wave washer part 212b is in a state of being contracted in the axial direction, and the entire coil 212 is shorter than the natural length Lco. Therefore, the coil 212 can generate an elastic force that expands the conductor at both ends of the coil 212 in the axial direction outward in the axial direction by the action of the wave washer part 212b.

Also, as shown in FIG. 14, in this example (fourth example), the coil 212 (one example of an elastic force generating part) is processed so that the conductor has a convex shape in the axial direction when viewed perpendicular to the axial direction in a part between both ends of the coil 212 in the axial direction, as in the case of the third example described above. Specifically, the coil 212 includes a disc spring part 212c processed so that the conductor has a substantially trapezoidal shape when viewed perpendicular to the axial direction, that is, a disc spring shape, in a part between both ends of the coil 212 in the axial direction. Also, as in the first example and the like described above, the coil 212 is configured so that the natural length Lco in the axial direction is longer than the core distance Dcc. As a result, the coil 212 is accommodated between a pair of stator cores 211 in the axial direction, so that the disc spring part 212c is in a state of being contracted in the axial direction, and the coil 212 as a whole is shorter than the natural length Lco. Therefore, the coil 212 can generate an elastic force that expands the conductor at both ends of the coil 212 in the axial direction outward in the axial direction by the action of the disc spring part 212c.

Also, as shown in FIG. 15, in this example (Example 5), coil 212 (an example of an elastic force generating portion) includes coil 212A and coil 212B that are divided in the axial direction.

The coil 212A has a lead-out portion 212A_E1 on the radially inner side at one end facing the axial stator core 211 (yoke portion 211A and claw pole 211B). The lead-out portion 212A_E1 is connected to an external terminal or a neutral point. The coil 212A has a lead-out portion 212A_E2 on the radially outer side at the other end facing the axial coil 212B.

At one end of the coil 212B facing the axial stator core 211 (yoke portion 211A and claw pole 211B), the coil 212B has a lead-out portion 212B_E1 on the radially inner side. The lead-out portion 212B_E1 is connected to an external terminal or a neutral point. In addition, at the other end of the coil 212B facing the axial coil 212A, the coil 212B has a lead-out portion 212B_E2 on the radially outer side.

The radially outer lead-out portions 212A_E2 and 212B_E2 of coil 212A and coil 212B, which face each other in the axial direction, are connected by lead-out wire 212L.

The axial dimension (i.e., natural length Lco) of coil 212 including coil 212A, lead wire 212L, and coil 212B is configured to be shorter than inter-core distance Dcc. As a result, coil 212 is housed between a pair of stator cores 211 in the axial direction, and lead wire 212L elastically deforms. Therefore, coil 212 can generate elastic force EF by the action of lead wire 212L, which expands both axial ends of coil 212, i.e., the ends of coil 212A and coil 212B facing stator core 211, outward in the axial direction.

Also, as shown in FIG. 16, in this example (sixth example), similar to the fifth example described above, the coil 212 (an example of an elastic force generating portion) includes coil 212A and coil 212B that are divided in the axial direction.

The lead-out portion 212A_E1 of the coil 212A is drawn out radially inward at one end facing the axial coil 212B. The lead-out portion 212A_E2 of the coil 212A is drawn out radially outward at the other end facing the axial stator core 211 (yoke portion 211A and claw pole 211B).

The lead-out portion 212B_E1 of the coil 212B is drawn out radially inward at one end facing the axial coil 212A. The lead-out portion 212B_E2 of the coil 212B is drawn out radially outward at the other end facing the axial stator core 211 (yoke portion 211A and claw pole 211B).

The radially outer lead-out portions 212A_E2 and 212B_E2 of coil 212A and coil 212B are connected by lead-out wire 212L, as in the fifth example described above.

The axial dimension (i.e., natural length Lco) of coil 212 including coil 212A, lead wire 212L, and coil 212B is configured to be shorter than inter-core distance Dcc. As a result, coil 212 is housed between a pair of stator cores 211 in the axial direction, as in the case of the fifth example described above, and lead wire 212L elastically deforms. Therefore, coil 212 can generate an elastic force EF by the action of lead wire 212L that expands both axial ends of coil 212, i.e., the ends of coil 212A and coil 212B facing stator core 211, outward in the axial direction.

As shown in FIG. 17, in this example (seventh example), the coil 212 (an example of an elastic force generating portion) has a lead-out portion 212_E1 provided on the radially outer side of both ends in the axial direction. The lead-out portion 212_E1 is connected to an external terminal or a neutral point through a lead wire 212L.

The lead wire 212L has a shape (hereinafter, "clamping portion") that can axially clamp the stator core 211 (claw pole 211B) between a first straight portion extending from the lead portion 212_E1 and a second straight portion provided further ahead. The lead wire 212L is fixed to the stator core 211 by clamping the stator core 211 (claw pole 211B) between the first straight portion and the second straight portion of the clamping portion. The clamping portion of the lead wire 212L is configured so that the gap, i.e., the axial distance between the first straight portion and the second straight portion, is smaller than the axial thickness of the stator core 211 (claw pole 211B). As a result, when the stator core 211 is sandwiched in the sandwiching portion, the lead wire 212L is elastically deformed by expanding the gap in the axial direction, and a compressive force (elastic force EF) acts on the stator core 211 from the first straight portion (lead portion 212_E1) and the second straight portion. Therefore, both axial ends of the coil 212 including the lead portion 212_E1 are pressed against the stator core 211 (yoke portion 211A and claw pole 211B) by the action of the lead wire 212L (sandwiching portion). Therefore, the coil 212 can generate an elastic force EF that expands both axial ends of the coil 212 outward in the axial direction by the action of the lead wire 212L.

As shown in FIG. 18, in this example (Example 8), an elastic member 214 is provided (inserted) between the layers at both axial ends of the coil 212, i.e., between the first coil portion at one end and the second coil portion at the other end. The elastic member 214 is, for example, an elastic resin, rubber, a leaf spring, a disc spring, or the like. If the elastic member 214 is a conductor, it is insulated, for example, with a resin coating or the like.

The axial dimension (natural length Lco) of the coil 212 with the elastic member 214 inserted is configured to be longer than the core distance Dcc. As a result, the coil 212 is accommodated between a pair of stator cores 211 in the axial direction, and the elastic member 214 is in a contracted state in the axial direction, making the coil 212 shorter overall than the natural length Lco. Therefore, the elastic member 214 can generate an elastic force that expands the conductors at both ends of the coil 212 outward in the axial direction.

<Insulation structure that does not impede coil expansion>
19 to 28 are vertical cross-sectional views showing first to tenth examples of the structure of the insulating portion 213 that does not inhibit the axial outward expansion of the conductor wire at both axial ends of the coil 212.

In addition, for simplicity, in Figures 19 to 28, the pair of stator cores 211 of the stator unit 21 are drawn as a single unit, and the claw magnetic pole portion 211B2 is omitted.

As shown in FIG. 19, in this example (first example), the insulating portion 213 includes insulating portions 213A and 213B.

The insulating portion 213A is disposed over the entire radial range between one axial end of the coil 212 and the stator core 211 (yoke portion 211A and claw pole 211B). In this example, the insulating portion 213A is disposed over a portion of the axial end side between the radial inner side of the coil 212 and the yoke portion 211C.

The insulating portion 213B is disposed over the entire radial range between the other axial end of the coil 212 and the stator core 211 (the yoke portion 211A and the claw pole 211B). In this example, the insulating portion 213B is disposed in a portion of the other axial end between the radial inner side of the coil 212 and the yoke portion 211C.

As a result, the insulating parts 213 at one end and the other end of the coil 212 in the axial direction are separated as insulating parts 213A and 213B. Therefore, when an elastic force that expands outward acts on the conductors at both ends of the coil 212, the insulating parts 213A and 213B can move in opposite directions (i.e., outward in the axial direction) in accordance with the expansion of both ends of the coil 212.

In this example, the insulating parts 213A and 213B are insulators made of resin or the like.

The insulating parts 213A and 213B are arranged in the region between the radial inside of the coil 212 and the yoke part 211C (hereinafter, "inner region") so that they overlap in the axial direction. Specifically, the insulating parts 213A and 213B have stepped shapes that are staggered in the radial direction in the parts that face each other in the axial direction. The insulating parts 213A and 213B are arranged in the inner region so that the stepped shapes of both parts fit together. As a result, even if the insulating parts 213A and 213B move outward in the axial direction, the above-mentioned stepped shape can maintain a state in which at least one of the insulating parts 213A and 213B exists between the yoke part 211C and the coil 212 throughout the entire axial direction. Therefore, even if the insulating parts 213A and 213B move in opposite directions in the axial direction, the insulation between the coil 212 and the stator core 211 can be ensured.

In this way, in this example (first example), the insulating parts 213A and 213B function to configure the insulating part 213 so as not to impede the axial outward expansion of the conductor wires at both ends of the coil 212.

Furthermore, as shown in FIG. 20, in this example (second example), insulating section 213 includes insulating sections 213A to 213C. Below, the following will mainly describe the parts that are different from the first example described above, and descriptions that are the same as or correspond to the first example described above may be simplified or omitted.

Insulating portion 213C is provided in the inner region so as to fill the space between insulating portions 213A and 213B. In this example, insulating portion 213C is an insulator made of resin or the like, similar to insulating portions 213A and 213B.

The insulating parts 213A and 213C have stepped shapes that are staggered in the radial direction at the portions that face each other in the axial direction. The insulating parts 213A and 213C are arranged in the inner region so that the stepped shapes of both parts fit together. Similarly, the insulating parts 213B and 213C have stepped shapes that are staggered in the radial direction at the portions that face each other in the axial direction. The insulating parts 213B and 213C are arranged in the inner region so that the stepped shapes of both parts fit together. As a result, even if the insulating parts 213A and 213B move outward in the axial direction, the above-mentioned stepped shape can maintain a state in which at least one of the insulating parts 213A to 213C exists between the yoke part 211C and the coil 212 throughout the entire axial direction. Therefore, even if the insulating parts 213A and 213B move in opposite directions in the axial direction, the insulation between the coil 212 and the stator core 211 can be ensured.

In this way, in this example (second example), the insulating parts 213A to 213C function to configure the insulating part 213 so as not to impede the axial outward expansion of the conductor wires at both ends of the coil 212.

As shown in FIG. 21, in this example (third example), insulating section 213 includes insulating sections 213A to 213C, as in the case of the second example described above. Below, the following description will focus on the parts that are different from the first example described above, and descriptions that are the same as or correspond to the first example described above may be simplified or omitted.

Insulating portion 213C is arranged in the inner region radially inward of insulating portions 213A and 213B and so as to cover the entire surface of yoke portion 211C in the axial direction. In this example, insulating portion 213C is insulating paper. As a result, even if insulating portions 213A and 213B move axially outward relative to each other, the action of insulating portion 213C can maintain at least insulating portion 213C existing between yoke portion 211C and coil 212 over the entire axial direction. Therefore, even if insulating portions 213A and 213B move axially in opposite directions, insulation between coil 212 and stator core 211 can be ensured.

In this example, the insulating portion 213C does not need to cover the entire surface of the yoke portion 211C in the axial direction. For example, the insulating portion 213C may be provided in a range in the axial direction where the insulating portions 213A, 213B between the coil 212 and the yoke portion 211C are not present, including the movable portion due to elastic force and a certain amount of margin. The same may be true for the insulating portions 213C in the fourth and sixth examples described below.

In this way, in this example (third example), the insulating parts 213A to 213C function to configure the insulating part 213 so as not to impede the axial outward expansion of the conductor wires at both ends of the coil 212.

Also, as shown in FIG. 22, in this example (fourth example), insulating section 213 includes insulating sections 213A to 213C, as in the second example and the like described above. Below, the following will focus on the differences from the first example and the like described above, and descriptions that are the same as or correspond to those in the first example may be simplified or omitted.

Insulating portion 213C is arranged in the inner region radially outward of insulating portions 213A and 213B and so as to cover the entire surface of coil 212 in the axial direction. As a result, even if insulating portions 213A and 213B move axially outward from each other, the action of insulating portion 213C can maintain at least insulating portion 213C existing between yoke portion 211C and coil 212 over the entire axial direction, as in the case of the third example described above. Therefore, even if insulating portions 213A and 213B move axially in opposite directions, insulation between coil 212 and stator core 211 can be ensured.

In this way, in this example (Example 4), the insulating parts 213A to 213C function to configure the insulating part 213 so as not to impede the axial outward expansion of the conductor wires at both ends of the coil 212.

As shown in FIG. 23, in this example (fifth example), insulating section 213 includes insulating sections 213A-213C, as in the second example and the like described above. In this example, insulating sections 213A-213C are insulating paper. Below, the following description will focus on the differences from the first example and the like described above, and descriptions that are the same as or correspond to the first example described above may be simplified or omitted.

The insulating portion 213A is disposed over the entire radial direction between one axial end of the coil 212 and the stator core 211 (the yoke portion 211A and the claw pole 211B).

The insulating portion 213B is disposed over the entire radial area between the other axial end of the coil 212 and the stator core 211 (yoke portion 211A and claw pole 211B).

The insulating portion 213C is provided in the inner region so as to cover the entire surface of the yoke portion 211C in the axial direction.

As a result, even if the insulating parts 213A and 213B move outward in the axial direction, as in the third example described above, the insulating part 213C acts to maintain the insulating part 213C between the yoke part 211C and the coil 212 throughout the entire axial direction. Therefore, even if the insulating parts 213A and 213B move in opposite directions in the axial direction, the insulation between the coil 212 and the stator core 211 can be ensured.

In this way, in this example (Example 5), the insulating parts 213A to 213C function to configure the insulating part 213 so as not to impede the axial outward expansion of the conductor wires at both ends of the coil 212.

As shown in FIG. 24, in this example (sixth example), insulating section 213 includes insulating sections 213A to 213C, as in the second example and the like described above. The following description will focus on the differences from the first example and the like described above, and descriptions that are the same as or correspond to those in the first example may be simplified or omitted.

The insulating portion 213A is integral with the coil 212 so as to cover the entire circumference of one end of the coil 212 in the axial direction.

The insulating portion 213B is integral with the coil 212 so as to cover the entire circumference of the other axial end of the coil 212.

In this example, the insulating parts 213A and 213B are resin molded.

The insulating portion 213C is disposed radially inward of the insulating portions 213A and 213B and so as to cover the entire surface of the yoke portion 211C in the axial direction. In this example, the insulating portion 213C is insulating paper. As a result, even if the insulating portions 213A and 213B move axially outward from each other, the insulating portion 213C acts to maintain at least the insulating portion 213C between the yoke portion 211C and the coil 212 over the entire axial direction, as in the third example described above. Therefore, even if the insulating portions 213A and 213B move axially in opposite directions, the insulation between the coil 212 and the stator core 211 can be ensured.

In this way, in this example (Example 6), the insulating parts 213A to 213C function to configure the insulating part 213 so as not to impede the axial outward expansion of the conductor wires at both ends of the coil 212.

As shown in FIG. 25, in this example (seventh example), insulating section 213 includes insulating sections 213A, 213B, and 213D. Below, the following will mainly describe the differences from the first example and other examples described above, and descriptions that are the same as or correspond to those in the first example may be simplified or omitted.

Insulating portion 213D is configured to connect insulating portions 213A and 213B in the inner region and to allow insulating portions 213A and 213B to be movable in the axial direction. Specifically, insulating portion 213D has a bellows structure that can be folded in the axial direction.

In this example, the insulating parts 213A, 213B, and 213D are insulators that are integrated by resin molding. This ensures that the insulation between the coil 212 and the stator core 211 is ensured.

In addition, when an elastic force that expands the conductors at both ends of coil 212 outward acts on insulating parts 213A and 213B, insulating parts 213D can expand in accordance with the expansion of both ends of coil 212 due to the action of the bellows structure. Therefore, insulating parts 213A and 213B can move in opposite directions (i.e., outward in the axial direction) due to the action of insulating part 213D.

In this way, in this example (Example 7), the insulating parts 213A, 213B, and 213D function to configure the insulating part 213 so as not to impede the axial outward expansion of the conductor wires at both ends of the coil 212.

As shown in FIG. 26, in this example (Example 8), insulating section 213 includes insulating sections 213A, 213B, and 213D, as in Example 7 described above. Below, the following description will focus on the differences from Example 1 described above, and descriptions that are the same as or correspond to Example 1 described above may be simplified or omitted.

In this example, the insulating parts 213A, 213B, and 213D are insulators that are integrated by resin molding, as in the seventh example described above. This ensures that the insulation between the coil 212 and the stator core 211 is ensured.

Also, as in the seventh example described above, the insulating part 213D is configured to connect the insulating parts 213A and 213B in the inner region, and to have axial mobility for the insulating parts 213A and 213B. Specifically, the insulating part 213D has a hollow part. This makes the thickness of the resin on the surface of the insulating part 213D relatively thin, making it easier to expand due to external forces. Therefore, when an elastic force that expands the conductors at both ends of the coil 212 outward acts on the insulating parts 213A and 213B, the insulating part 213D can reliably expand in accordance with the expansion of both ends of the coil 212 due to the action of the hollow part (i.e., thinning). Therefore, the insulating parts 213A and 213B can move in opposite directions (i.e., outward in the axial direction) due to the action of the insulating part 213D.

In this way, in this example (Example 8), the insulating parts 213A, 213B, and 213D function to configure the insulating part 213 so as not to impede the axial outward expansion of the conductor wires at both ends of the coil 212.

Also, as shown in FIG. 27, in this example (Example 9), the insulating portion 213 includes insulating portions 213A, 213B, and 213D, similar to the above-mentioned Example 7, etc.

In this example, the insulating parts 213A, 213B, and 213D are insulators that are integrated by resin molding, as in the seventh example and other examples described above. This ensures that the insulation between the coil 212 and the stator core 211 is ensured.

Also, as in the seventh example described above, the insulating portion 213D is configured to connect the insulating portions 213A and 213B in the inner region, and to allow the insulating portions 213A and 213B to have axial mobility. Specifically, the insulating portion 213D is configured to have a sufficiently thinner radial thickness than the insulating portions 213A and 213B. This makes the insulating portion 213D more easily expandable by an external force. Therefore, when an elastic force that expands the conductors at both ends of the coil 212 outward acts on the insulating portions 213A and 213B, the insulating portion 213D can reliably expand in accordance with the expansion of both ends of the coil 212 due to the thinning effect. Therefore, the insulating portions 213A and 213B can move in opposite directions (i.e., outward in the axial direction) due to the action of the insulating portion 213D.

In this way, in this example (Example 9), the insulating parts 213A, 213B, and 213D function to configure the insulating part 213 so as not to impede the axial outward expansion of the conductor wires at both ends of the coil 212.

Also, as shown in FIG. 28, in this example (10th example), the insulating portion 213 is a resin mold provided on the entire axial inner surface of the pair of stator cores 211 of the stator unit 21 and the entire radial outer surface of the yoke portion 211C.

This increases the degree of contact between the stator core 211 and the insulating section 213 relatively, thereby reducing thermal resistance. In addition, because the insulating section 213 is disposed on the stator core 211, it does not impede the axial outward expansion of the conductors at both ends of the coil 212 in the axial direction.

In this way, in this example, the insulating portion 213 is configured as a resin mold provided on the surface of the stator core 211, so that it can be configured so as not to impede the axial outward expansion of the conductors at both ends of the coil 212 in the axial direction.

Also, unlike the first to tenth examples described above, the insulating portion 213 may be a resin insulating coating applied to the surface of the conductor of the coil 212. This allows the insulating portion 213 to freely follow the movement of the conductor that constitutes the coil 212. Therefore, the insulating portion 213 can be configured so as not to impede the axial outward expansion of the conductor at both ends of the coil 212 in the axial direction.

[Transformations/Changes]
Although the embodiments have been described above, it will be understood that various changes in form and details are possible without departing from the spirit and scope of the claims.

For example, the structure for cooling the coil 212 in the above-described embodiment may be applied to an inner rotor type claw pole motor in which a rotor is rotatably arranged radially inside a claw pole type stator. In this case, claw poles are formed that protrude radially inward from the inner periphery of the stator core.

The structure for cooling the coil 212 in the above-described embodiment may also be adopted in other electromagnetic devices other than claw-pole motors, specifically other electromagnetic devices in which a core is disposed facing the outside of both ends of the coil in the winding axis direction. The other electromagnetic devices may include, for example, a thrust magnetic bearing or a reactor. This can improve the cooling performance of the coil of the other electromagnetic devices, as in the above-described embodiment.

1. Claw pole motor (electromagnetic device)
REFERENCE SIGNS LIST 10 rotor 11, 11A to 11C rotor core 12 permanent magnet 13 rotating shaft member 14 connecting member 20 stator 21, 21A to 21C stator unit 22 interphase member 22A UV interphase member 22B VW interphase member 23 end member 24 insertion member 25, 26 bearing 30 fixing member 211 stator core (core)
211A Yoke portion 211B Claw magnetic pole 211C Yoke portion 211D Insertion hole 212 Coil (elastic force generating portion)
213, 213A to 213D: Insulating portion 214: Elastic member (elastic force generating portion)

Claims (6)

A coil formed by winding a conductor;
a core disposed outside both ends of the coil in a winding axis direction so as to face each other;
an elastic force generating unit configured to generate an elastic force so as to expand the conductor wire at both ends of the coil in the winding axis direction outward in the winding axis direction ,
the elastic force generating portion is the coil,
The coil generates the elastic force, and both ends in the winding axis direction are in contact with opposing members over the entire circumference .
Electromagnetic device. an insulating portion for insulating the coil from the core;
The insulating portion is configured to be movable in accordance with the outward expansion of the conductor wire at both ends of the coil in the winding axis direction.
10. The electromagnetic device of claim 1. At least a part of the conductor of the coil is processed into a coil spring shape.
3. An electromagnetic device according to claim 1 or 2 . The coil is processed so that a part of the conductor has a convex shape in the winding axis direction when viewed from a direction perpendicular to the winding axis.
3. An electromagnetic device according to claim 1 or 2 . The coil lead wire generates the elastic force.
3. An electromagnetic device according to claim 1 or 2 . The conductor wire is a square wire or a rectangular wire.
6. An electromagnetic device according to any one of the preceding claims.

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