JP2017229178A - Bobbin structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a bobbin structure capable of realizing a mechanism for attaching a bobbin to a stator without specifically complicating the structure, increasing a cost, considering an influence to a magnetic field structure, and having an advantageous to suppress a temperature rising of the coil when adopting a material of which a thermal conductivity is high to the bobbin.SOLUTION: A stator 38 is sandwiched from both sides by a motor base 36, a support medium 37 of the stator 38, and a motor support 35 in a rotational axial direction. A bobbin 45 includes an engagement part 50 in an inner diameter side of the stator 38 so as to be mounted to the stator 38. In a state where the stator 38 is sandwiched from both sides by the motor base 36 and the motor support 35, the engagement part 50 of the bobbin 45 is engaged with the motor base 36 and engagement parts 60 and 70 of the motor support 35, and the bobbin 45 is fixed to the stator 38.SELECTED DRAWING: Figure 7

Description

  The present invention relates to a bobbin structure of an outer rotor type in-wheel motor used for driving wheels of an electric vehicle.

  An in-wheel motor is known as a motor used for driving a motor of an electric vehicle. The in-wheel motor is used by being built inside the wheel. The rotation of the in-wheel motor rotates the tire attached to the wheel. In the outer rotor type in-wheel motor, the coil is wound around the teeth of the stator protruding radially in the circumferential direction. A bobbin that is an insulator and serves as a guide for the winding is used for winding the coil, and the coil is wound around the bobbin. For example, Patent Document 1 below discloses a bobbin fixing structure in which an insulator (bobbin) is fixed to a stator core, and a hook-like claw portion integrated with the insulator is engaged with an inner peripheral wall of the stator core.

  On the other hand, in the outer rotor type in-wheel motor, the motor is arranged coaxially with the wheel shaft, and the rotor as the rotor rotates at the same speed as the speed of the wheel. The rotor is integrated with the magnet and is arranged so as to surround the outside of the armature provided with the coil. Magnets are required to have high heat resistance in order to avoid demagnetization during use. Although heat resistance can be improved by including rare earth dysprosium or the like in the magnet, it is desirable that the amount of expensive dysprosium or the like is reduced or not contained. As described above, the outer rotor type motor has a structure that is advantageous for heat dissipation of the magnet because the magnet is outside the armature. Adoption of is desired.

JP 2012-105372 A

  In the case of adopting a bobbin fixing structure in which a hook-like claw portion integrated with an insulator (bobbin) is engaged with the inner peripheral wall of the stator core as in Patent Document 1, the hook-like claw portion of the insulator extends to the inner diameter side of the stator core. Therefore, the hook-shaped claw portion interferes with the support member of the stator core. This interference can be prevented by adopting a structure in which the hook-shaped claw portion is engaged with the hole provided in the stator core, but the magnetic field structure of the stator core is affected by providing the hole.

  In order not to interfere with the magnetic field structure of the stator core, it is necessary to lengthen the stator core in the inner diameter direction, and this configuration has a problem that the weight and cost of the electromagnetic steel sheet increase.

  Moreover, if the effect of suppressing the temperature rise of the coil is obtained, the temperature increase of the magnet disposed in the vicinity of the coil is also suppressed. However, the fixing structure of the insulator disclosed in Patent Document 1 aims to suppress the temperature increase of the coil. It was not a structure.

  The present invention solves the above-described conventional problems, and does not increase the complexity of the structure, increase the cost, and consider the influence on the magnetic field structure. In addition, an object of the present invention is to provide a bobbin structure that is advantageous for suppressing temperature rise of a coil when a material having high thermal conductivity is adopted for the bobbin.

  In order to achieve the above object, a bobbin structure of the present invention is an outer rotor type in-wheel motor bobbin structure used for driving a wheel of an electric vehicle, and the bobbin structure is a bobbin for winding a coil. The stator is sandwiched from both sides by a motor base and a motor support that are the support members of the stator in the rotation axis direction, and the bobbin is attached to the stator. In this state, an engagement portion is provided on the inner diameter side of the stator, and in a state where the stator is sandwiched from both sides by the motor base and the motor support, the engagement portion of the bobbin is the motor base and the motor support. The bobbin is fixed to the stator by engaging with the engaging portion.

  According to this configuration, the motor support and the motor base, which are originally support members of the stator, can be shared as the bobbin mounting member, so that it is not necessary to add a dedicated part and the structure becomes specially complicated. In addition, the structure for attaching the bobbin to the stator can be realized without increasing the cost. Further, in this configuration, the bobbin engaging portion engages with the motor base and the motor support engaging portion, and the bobbin is fixed to the stator. Therefore, there is no need to process the stator, and the magnetic field generated by the processing of the stator. The structure for mounting the bobbin to the stator can be realized without considering the influence on the structure. In addition, when a material with high thermal conductivity is used for the bobbin, the coil heat is directly transmitted not only to the stator but also to both the motor support and the motor base, which are the support members of the stator. It becomes advantageous for suppression.

  In the bobbin structure of the present invention, the bobbin material is preferably a material that achieves both high insulation and high thermal conductivity. According to this configuration, it is possible to increase the thermal conductivity of the bobbin while ensuring the electrical insulation originally required for the bobbin, and by increasing the thermal conductivity of the bobbin, the heat of the coil is only the stator as described above. Instead, it is directly transmitted to both the motor support and the motor base, which are the support members of the stator, which is advantageous in suppressing the temperature rise of the coil.

  In addition, it is preferable that the engagement between the engagement portion of the bobbin and the engagement portion of the motor base and the motor support is at least an engagement of the convex portions. According to this configuration, the bobbin can be securely fixed with a simple structure.

  Further, in a state where the bobbin is mounted on the stator, it is preferable that the engaging portion of the bobbin does not extend inward from the inner peripheral surface of the stator. According to this configuration, when the motor support and the motor base are mounted, these parts do not interfere with the engaging portion. Therefore, it is necessary to perform special processing for preventing the interference on the motor support and the motor base. Absent.

  The effects of the present invention are as described above. In summary, the stator support member can be used as a bobbin attachment member, and the bobbin can be used without any particular complexity or cost. The mounting structure to the stator can be realized, and the stator does not need to be processed at all.Therefore, the mounting structure of the bobbin to the stator can be realized without considering the influence on the magnetic field structure due to the processing of the stator. When a material having high thermal conductivity is adopted, it is advantageous for suppressing the temperature rise of the coil.

Sectional drawing which shows the internal structure of the in-wheel motor which concerns on one Embodiment of this invention. The disassembled perspective view of the in-wheel motor shown in FIG. The perspective view of the bobbin which concerns on one Embodiment of this invention. The perspective view which shows the state which wound the coil around the bobbin shown in FIG. The perspective view which shows the state before mounting | wearing a stator with a motor support and a motor base in one Embodiment of this invention. The perspective view which shows a mode that a bobbin is mounted | worn to a stator in one Embodiment of this invention. The longitudinal section in the state where a motor support and a motor base were attached to a stator in one embodiment of the present invention. In one Embodiment of this invention, the longitudinal cross-sectional view which concerns on another embodiment in the state which mounted | wore the stator with the motor base and the motor support.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. The bobbin structure according to the present embodiment is a bobbin structure of an outer rotor type in-wheel motor used for driving wheels of an electric vehicle. An in-wheel motor is used by being built inside a wheel of an electric vehicle. Initially, the motor structure of an in-wheel motor is demonstrated, referring FIG.1 and FIG.2.

  FIG. 1 is a cross-sectional view showing the internal structure of the in-wheel motor 1. For convenience of illustration, the illustration is partially simplified, and illustration of a tire attached to the wheel 2 is omitted. FIG. 2 is an exploded perspective view of the in-wheel motor 1. FIG. 1 illustrates a state in which the wheel 2 is attached to the in-wheel motor 1, but the case 10 is fixed to the hub unit 21 before the wheel 2 is attached to the in-wheel motor 1. In FIG. 1, a bolt 20 passes through the flange portion of the hub unit 21, the case 10, and the wheel 2, and the bolt 20 is tightened by a nut (not shown). As a result, the wheel 2 is integrally fixed to the in-wheel motor 1.

  In FIG. 2, a groove 22 is formed on the inner peripheral surface of the case 10, and a convex portion 24 is formed on an annular rotor 23. The magnet 25 is fitted in the groove 27 of the rotor 23 and is fixed to the inner peripheral surface side of the rotor 23. The rotor 23 is accommodated in the case 10 in a state where the convex portion 24 is fitted in the groove 22 of the case 10. In FIG. 1, the rotor clamp 33 and the dust seal 43 are fixed to the case 10 by screws 44, and the rotor 23 is fixed to the inner peripheral surface side of the case 10 while being sandwiched between the spacer 31 and the spacer 32.

  The brake shaft 16 is inserted through the through hole 26 of the hub unit 21 shown in FIG. In the state of FIG. 1, the brake shaft 16 is fixed to the hub unit 21, and the brake disc 15 is fixed to the brake shaft 16 by bolts 17 and nuts (not shown). According to the above configuration, the hub unit 21, the case 10, the rotor 23, the brake shaft 16 and the brake disc 15 have an integrated structure, and the wheel 2 is fixed to the integrated structure.

  The in-wheel motor 1 of this embodiment is an outer rotor type, and the rotor 23 that is an outer rotor rotates. According to the integrated structure, the inner diameter side of the bearing (not shown) of the case 10 and the hub unit 21, the brake shaft 16 and the brake disk 15 rotate at the same speed as the rotation of the rotor 23, and are integrated with them. The wheel 2 rotates.

  Although details will be described later, in FIG. 2, a bobbin 45 is attached to a tooth 39 of an annular stator 38, and a coil 34 is wound around the bobbin 45. The coil wire of the coil 34 is connected to the outer periphery of the bus bar ring 41. The motor support 35 and the motor base 36 shown in FIG. 2 constitute a support 37 that supports the stator 38. The motor support 35 and the motor base 36 constituting the support 37 are fixed with bolts, and the stator 38 is fixed to the support 37. The support body 37 is fixed to the knuckle 5 (see FIG. 1) with a bolt (not shown) through the seal plate. According to this configuration, the stator 38 is fixed to the vehicle body via the support body 37.

  According to the above motor structure, the stator 38 and the support body 37 and the seal plate 42 integrated therewith are fixed portions that do not rotate. In the state of FIG. 2, the support body 37 and the seal plate 42 are fixed to the hub unit 21. As described above, the hub unit 21 rotates integrally with the rotation of the wheel 2. However, since the hub unit 21 has a built-in bearing (not shown), even if the mounting side of the wheel 2 rotates, the mounting side of the support 37 and the seal plate 42 is fixed. In FIG. 1, a gap is formed between the rotor 23 in which the magnet 25 is integrated and the teeth 39 around which the coil 34 is wound. When the coil 34 is energized, the rotor 23 integrated with the magnet 25 rotates.

  Hereinafter, the bobbin structure according to the present embodiment will be specifically described. FIG. 3 shows a perspective view of the bobbin 45. The bobbin 45 serves as a winding guide by the coil 34 (see FIG. 4). FIG. 3 shows a state where the coil 34 is not wound around the bobbin 45. The bobbin 45 is a resin molded product. In the example of FIG. 3, in order to facilitate molding, the bobbin 45 has a two-divided structure, and the upper and lower bobbin bodies 46 constitute one bobbin 45. A hollow portion 47 is formed in the bobbin 45, and the teeth 39 of the stator 38 are inserted into the hollow portion 47 when the bobbin 45 is attached to the stator 38.

  Each bobbin main body 46 is provided with an engaging portion 50 on the inner diameter side of the stator 38 in a state where the bobbin main body 46 is inserted into and mounted on the teeth 39 of the stator 38. The engaging portion 50 is for engaging with the support body 37, and the convex portion 51 and the concave portion 52 form a groove. The engaging portion 50 is provided in each of the pair of bobbin main bodies 46 and is disposed on the upper end side and the lower end side of the bobbin 45. FIG. 4 is a perspective view showing a state where the coil 34 is wound around the bobbin 45. In the state of this figure, the teeth 39 of the stator 38 are inserted into the hollow portion 47 and the bobbin 45 is mounted on the stator 38.

  FIG. 5 is a perspective view showing a state before the motor support 35 and the motor base 36 constituting the support member 37 are mounted on the stator 38. FIG. 6 is a perspective view showing how the bobbin 45 is mounted on the stator 38. 5 and 6 are different in angle, and FIG. 5 illustrates the lower ends of the motor support 35 and the motor base 36, and FIG. 6 illustrates the upper ends.

  In the state of FIG. 5, the bobbin 45 is not attached to the stator 38. A large number of teeth 39 extend radially in the circumferential direction of the stator 38. The motor base 36 is provided with an engaging portion 60. The engaging part 60 is for engaging with the engaging part 50 of the bobbin 45, and a groove is formed by a convex part 61 and a concave part 62 formed in the circumferential direction, respectively. Similarly, an engagement portion 70 is formed on the motor support 35. The engaging part 70 is for engaging with the engaging part 50 of the bobbin 45, and as shown in FIG. 6, a groove is formed by the convex part 61 and the concave part 62 formed in the circumferential direction, respectively. doing

  FIG. 6 also shows the bobbin 45 before being attached to the stator 38 for convenience. As shown in this figure, the teeth 39 of the stator 38 are inserted into the hollow portion 47 of the bobbin 45, and the bobbin 45 is attached to the stator 38. FIG. 6 shows a state in which the bobbin 45 is attached to one tooth 39 of the stator 38, but the bobbin 45 is sequentially attached to all teeth thereafter.

  In FIG. 6, when the mounting of the bobbin 45 is completed for all of the teeth 39, the stator 38 is sandwiched from both sides by the motor base 36 and the motor support 35 that are the support bodies of the stator 38 in the rotation axis direction. More specifically, the outer peripheral surface 63 of the motor base 36 and the outer peripheral surface 73 of the motor support 35 are fitted into the inner peripheral surface 48 of the stator 38, and the motor base 36 and the motor support 35 are attached to the stator 38.

  FIG. 7 shows a longitudinal sectional view of the stator 38 with the motor base 36 and the motor support 35 attached thereto. In this figure, the coil 34 wound around the bobbin 45 is shown in a simplified manner. At the upper part of the bobbin 45, the engaging part 50 of the bobbin 45 and the engaging part 60 of the motor base 36 are engaged. More specifically, the convex portion 61 of the motor base 36 is engaged with the concave portion 52 of the bobbin 45, and the convex portion 51 of the bobbin 45 is engaged with the concave portion 62 of the motor base 36.

  At the lower part of the bobbin 45, the engaging part 50 of the bobbin 45 and the engaging part 70 of the motor support 35 are engaged. More specifically, the convex portion 71 of the motor support 35 is engaged with the concave portion 52 of the bobbin 45, and the convex portion 51 of the bobbin 45 is engaged with the concave portion 72 of the motor support 35.

  In FIG. 7, since the motor base 36 and the motor support 35 are fixed to each other, the engagement state of the engagement portion 50 of the bobbin 45 and the engagement portion 60 of the motor base 36 in the upper portion of the bobbin 45 and the lower portion of the bobbin 45 The engagement state between the engagement portion 50 of the bobbin 45 and the engagement portion 70 of the motor support 35 is maintained. As a result, the movement of the bobbin 45 is restricted, and the bobbin 45 is fixed to the teeth 39 of the stator 38.

  FIG. 8 is a longitudinal sectional view according to another embodiment in a state where the motor base 36 and the motor support 35 are mounted on the stator 38. In the configuration of this figure, the convex portion 51 constituting the engaging portion 50 of the bobbin 45 is formed with an inclined surface, and the thickness of the concave portion 52 is thinned. The engagement of the bobbin 45 shown in FIG. The shape of the part 50 is different.

  In the above embodiment, as described with reference to FIG. 6, the example in which the motor base 36 and the motor support 35 are mounted after the bobbin 45 is mounted has been described. However, the shape of the engaging portion 50 illustrated in FIG. In this case, the bobbin 45 can be mounted after the motor base 36 and the motor support 35 are mounted. That is, if the motor base 36 and the motor support 35 are mounted on the stator 38 in advance and the convex portion 51 of the engaging portion 50 of the bobbin 45 is inserted into the gap between the convex portion 61 and the stator 38, the engagement is achieved. The joint portion 50 moves forward while being elastically deformed, and then engages with the engaging portion 60 of the motor base 36 and the engaging portion 70 of the motor support 35.

  The bobbin structure according to this embodiment has been described above. However, according to the bobbin structure as described above, the motor support 35 and the motor base 36 that are originally support members of the stator 39 are shared as the attachment members of the bobbin 45. Therefore, it is not necessary to add dedicated parts, and the structure is not particularly complicated and the cost is not increased. In particular, as in the configuration shown in FIG. 7, the engagement between the engagement portion 50 of the bobbin 45, the engagement portion 60 of the motor base 36, and the engagement portion 70 of the motor support 35 is engaged by a convex portion and a concave portion. Then, the bobbin 45 can be securely fixed with a simple structure.

  Further, as shown in FIG. 7, if the engagement portion 50 of the bobbin 45 does not extend inward from the inner peripheral surface 48 of the stator 38 when the bobbin 45 is mounted on the stator 38, the motor When the support 35 and the motor base 36 are mounted, these components do not interfere with the engaging portion 50, so that it is not necessary to perform special processing for preventing the interference on the motor support 35 and the motor base 36.

  Furthermore, in the bobbin structure of the present embodiment, since the stator 39 does not need to be processed at all, it is not necessary to consider the influence on the magnetic field structure of the stator. For example, if the engagement claw provided on the bobbin is engaged with the hole provided on the stator, the hole has an effect on the magnetic field structure of the stator. In order not to interfere with the magnetic field structure of the stator, it is necessary to lengthen the stator in the inner diameter direction. In this configuration, the amount of use of the electromagnetic steel sheet increases, so that the weight and cost increase.

  Here, if a material having high thermal conductivity is adopted for the bobbin 45, the heat of the coil 34 is quickly transmitted to the stator 39, so that the temperature rise of the coil 34 can be suppressed. As will be described later, when the bobbin structure according to the present embodiment employs a material having high thermal conductivity for the bobbin 45, the bobbin structure has a structure that is more advantageous for suppressing the temperature rise of the coil 34. When the temperature rise of the coil 34 is suppressed, the temperature rise of the magnet 25 disposed in the vicinity of the coil 34 is also suppressed, and the magnet 25 (see FIGS. 1 and 2) has a content such as dysprosium that is an expensive rare earth. The effect of reducing is obtained.

  Specifically, in FIG. 7, when the coil 34 is energized, the temperature of the coil 34, which is a heating element, rises. Since the coil 34 is wound around the bobbin 45 and the bobbin 45 is mounted on the teeth 39 of the stator 38, the heat of the coil 34 is transmitted to the stator 38 via the bobbin 45. As shown in FIG. 1, since the teeth 39 of the stator 38 are opposed to the magnet 25 through a gap, when the temperature of the coil 34 rises, not only the stator 38 but also the magnet 25 rises in temperature.

  The magnet 25 is required to have high heat resistance in order to avoid demagnetization during use. The magnet can improve heat resistance by containing dysprosium which is a rare earth. For example, irreversible demagnetization occurs in which the magnetic force of the magnet is permanently lost if it does not contain dysprosium or the like when the temperature becomes higher than 100 ° C. under a situation where a reverse magnetic field is applied to the magnet. . On the other hand, it is desirable that the amount of expensive dysprosium or the like is reduced or not contained.

  The bobbin structure of the present embodiment is a bobbin structure of an outer rotor type in-wheel motor, and the outer rotor type motor has a magnet 25 outside the armature provided with the coil 34 as shown in FIG. This is advantageous for heat dissipation of 25. In this embodiment, in addition to adopting an outer rotor type that is advantageous for heat dissipation, a bobbin structure that is advantageous for suppressing temperature rise of the coil 34 is adopted, and therefore, a material having high thermal conductivity is adopted for the bobbin 45. This is advantageous in suppressing the temperature rise of the magnet 25. This makes it possible to suppress the content of dysprosium, which is a rare earth.

  Hereinafter, description will be made on the assumption that a material having high thermal conductivity is adopted for the bobbin 45. As shown in FIG. 7, the coil 34 is wound around the bobbin 45, and the bobbin 45 is attached to the teeth 39 of the stator 38, so that the heat of the coil 34 is directly transmitted to the stator 38 through the bobbin 45. Furthermore, in the present embodiment, as described above, since the bobbin 45 is engaged with both the motor support 35 and the motor base 36, the heat of the coil 34 passes through the bobbin 45, and the motor support having a large part and a large heat capacity. It is transmitted directly to both 35 and the motor base 36. That is, according to the bobbin structure according to the present embodiment, the heat of the coil 34 is directly applied not only to the stator 38 but also to both the motor support 35 and the motor base 36 by adopting a material having high thermal conductivity for the bobbin 45. Therefore, it is advantageous for suppressing the temperature rise of the coil 34.

Next, the material of the bobbin 45 will be described. As described above, if the thermal conductivity of the bobbin 45 is high, it is advantageous for suppressing the temperature increase of the coil 34 and the temperature increase of the magnet 25 associated therewith. On the other hand, since the material of the bobbin 45 is required to have electrical insulation, in order to suppress the temperature rise of the magnet 25 as described above, the material of the bobbin 45 has high electrical insulation and high thermal conductivity, which are contradictory characteristics. Must be satisfied at the same time. A specific example of such a material is a high thermal conductivity PPS (polyphenylene sulfide) resin. High thermal conductivity PPS resins have thermal conductivity (room temperature) of 3 (W / m · K) or more and volume resistivity (electrical insulation) of 10 ¹⁶ (Ω · cm) or more. Therefore, it is possible to achieve both high electrical insulation and high thermal conductivity, which is suitable as a material for the bobbin 45.

  As mentioned above, although one Embodiment of this invention was described, this invention is not restricted to this, The structure changed suitably is also contained. For example, the in-wheel motor 1 shown in FIG. 1 and FIG. 2 is an example, and may be changed as appropriate without changing the structure of the outer rotor type. The bobbin 45 has been described with reference to the example of the two-divided structure in FIG. 3, but may be integrally formed.

  Further, the engagement structure between the bobbin 45, the motor base 36, and the motor support 35 is not limited to the structure shown in FIG. 7, and may be changed as appropriate. For example, in FIG. 7, the engagement by the engaging portions 50, 60 and 70 is configured such that the convex portions 51 and 71 are fitted into the groove portions formed by the concave portions 62 and 52, but the groove shape is not necessarily formed. It is not necessary to have an engaging structure in which the convex portions only engage with each other.

DESCRIPTION OF SYMBOLS 1 In-wheel motor 25 Magnet 34 Coil 35 Motor support 36 Motor base 37 Support body 38 Stator 39 Tooth 45 Bobbin 47 Hollow part 50, 60, 70 Engagement part 51, 61, 71 Convex part 52, 62, 72 Concave part

In the state of FIG. 5, the bobbin 45 is not attached to the stator 38. A large number of teeth 39 extend radially in the circumferential direction of the stator 38. The motor base 36 is provided with an engaging portion 60. The engaging part 60 is for engaging with the engaging part 50 of the bobbin 45, and a groove is formed by a convex part 61 and a concave part 62 formed in the circumferential direction, respectively. Similarly, an engagement portion 70 is formed on the motor support 35. The engaging part 70 is for engaging with the engaging part 50 of the bobbin 45, and as shown in FIG. 6, a groove is formed by the convex part 71 and the concave part 72 formed in the circumferential direction, respectively. Is doing .

Claims (4)

An outer rotor type in-wheel motor bobbin structure used for driving wheels of an electric vehicle,
The bobbin structure is a structure for inserting and fixing a bobbin for winding a coil into the teeth of the stator,
The stator is sandwiched from both sides by a motor base and a motor support which are support members of the stator in the rotation axis direction,
The bobbin is provided with an engaging portion on the inner diameter side of the stator in a state of being mounted on the stator,
In a state where the stator is sandwiched from both sides by the motor base and the motor support, the engaging portion of the bobbin engages with the engaging portion of the motor base and the motor support, and the bobbin is fixed to the stator. Bobbin structure characterized by that.   The bobbin structure according to claim 1, wherein the bobbin material is a material that achieves both high insulation and high thermal conductivity.   3. The bobbin structure according to claim 1, wherein the engagement between the engagement portion of the bobbin and the engagement portion of the motor base and the motor support is at least an engagement between the convex portions. The bobbin structure according to any one of claims 1 to 3, wherein an engagement portion of the bobbin does not extend inward from an inner peripheral surface of the stator in a state where the bobbin is mounted on the stator.

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