WO2020039608A1

WO2020039608A1 - Outer rotor-type motor and electric vehicle

Info

Publication number: WO2020039608A1
Application number: PCT/JP2019/000526
Authority: WO
Inventors: 清水　浩; 正樹川口; 隆昌加藤
Original assignee: 株式会社ｅ－Ｇｌｅ
Priority date: 2018-08-24
Filing date: 2019-01-10
Publication date: 2020-02-27
Also published as: CN110149017A; TW202010220A; JP6443958B1; JP2020031524A

Abstract

Provided are: an outer rotor-type motor that has a bobbin attachment structure in which bobbins can be simply attached to a stator and there is no danger of damage to engagement parts of the bobbins in use, even when strongly holding the stator, and that has an excellent heat dissipation effect; and an electric vehicle provided with the outer rotor-type motor. This outer rotor-type motor has: a stator core (21) having a plurality of teeth (21b) in a radial shape on the outer diameter side of an annular base part; a stator center (22) and a stator guide (23) that sandwich the stator core (21) from both axial sides and position the stator core; and bobbins (30) around which coils (40) are wound and which are attached to the plurality of teeth (21b) of the stator core (21). In a state in which the bobbins (30) are attached to the stator core (21), engagement pieces (22c), (23c) provided to the stator center (22) and the stator guide (23) are inserted into engagement holes (34a), (35a) of the bobbins (30), and the engagement pieces (22c), (23c) are fixed, with the stator core (21) therebetween.

Description

Outer rotor type motor and electric vehicle

The present invention relates to an outer rotor type motor and an electric vehicle.
This application claims the priority based on Japanese Patent Application No. 2018-157654 filed on Aug. 24, 2018, and incorporates all the contents described in the Japanese application.

イン An in-wheel motor that mounts a drive motor of an electric vehicle in a wheel has been proposed. This in-wheel motor has no energy loss due to the conventional gears, drive shafts, and the like, so that improvement in drive efficiency and cruising distance can be expected. As an in-wheel motor, in an outer rotor type (eversion type) motor in which a permanent magnet rotates, a stator (stator) is constituted by a ring-shaped yoke portion and an iron core having a plurality of teeth on an outer diameter side thereof. The stator coil wound around the tooth may be wound directly on the tooth or may be wound once on a bobbin and inserted into the tooth.

(4) In the case of using a bobbin, if the bobbin moves in the radial direction during use of the motor, the bobbin comes into contact with the rotating outer rotor and causes serious trouble. Therefore, it is necessary to firmly fix the bobbin to the teeth. For example, in Patent Document 1, in a motor having a motor base and a motor support that supports the stator by sandwiching the stator from both sides in the axial direction, the bobbin mounted on the stator is fixed using the motor base and the motor support. Is disclosed.

Japanese Patent No. 61212525

In the bobbin structure disclosed in Patent Literature 1, the bobbin has an engagement portion on the inner diameter side of the stator, and the engagement portion of the bobbin is also provided in a state where the stator is sandwiched from both sides by the motor base and the motor support. The bobbin is fixed to the stator while being sandwiched from both sides by the engagement portions of the motor base and the motor support. Therefore, by assembling the motor base and the motor support, the bobbin can be fixed at the same time, and the bobbin can be prevented from moving in the radial direction.

However, in the bobbin structure disclosed in Patent Literature 1, when the stator is sandwiched and fixed from both sides by the motor base and the motor support, depending on the dimensional accuracy of the members, the engagement portion provided on the bobbin also has the motor base and the motor support. Therefore, there is a possibility that the pressing force acts on the engaging portion of the bobbin. Since the in-wheel motor is provided in the wheel of the automobile, the vibration of the wheel is directly transmitted to the components of the motor during use. For this reason, the stator of the in-wheel motor needs to be firmly attached to the motor base and the motor support. However, if a strong force acts on the engagement portion of the bobbin, the engagement portion of the bobbin may be damaged during use. .

The present invention has been made in view of these circumstances, and the bobbin can be easily attached to the stator core, and even if the stator core is firmly held, there is no possibility that the engagement portion of the bobbin will be damaged during use. It is an object of the present invention to provide an outer rotor type motor having a bobbin mounting structure and having an excellent heat radiation effect, and to provide an electric vehicle equipped with the outer rotor type motor.

In order to solve the above problem, a first technical means of the present invention is a stator core having a plurality of teeth radially on an outer diameter side of an annular base, a stator center and a stator guide for positioning the stator core from both axial sides. An outer rotor type motor having a bobbin on which a coil is wound and mounted on the teeth of the plurality of stator cores, and penetrates in the axial direction on both sides in the axial direction on the inner diameter side of the bobbin. An engaging portion that has an engaging hole and protrudes is provided, and a plurality of engaging pieces that protrude in the axial direction are provided on outer peripheral portions of the stator center and the stator guide, respectively, and the bobbin is mounted on the stator core. In this state, the tips of the engagement pieces of the stator center and the stator guide are inserted into the engagement holes of the bobbin, and the engagement pieces are It is characterized in that the axial end faces of the serial stator core are positioned in contact with the stator core in the axial direction.

A second technical means is the first technical means, wherein the bobbin has two flange portions which are separated in a radial direction in a state where the bobbin is mounted on the stator core, and the bobbin has a flange portion on an inner diameter side. A notch is provided at a location on the axial direction, into which the winding end of the coil is inserted.

A third technical means is an electric vehicle, wherein the outer rotor type motor of the first or second technical means is provided on a wheel of a wheel, and the wheel is directly driven by the outer rotor type motor. It is a feature.

According to the present invention, the bobbin can be easily attached to the stator, and the engagement pieces provided on the stator center and the stator guide for holding the stator abut on the axial end surfaces of the stator. There is no pressing force acting on the engaging portion, and there is no possibility that the engaging portion of the bobbin is damaged during use. Further, heat from the stator is easily transmitted to the stator center and the stator guide via the engagement pieces provided on the stator center and the stator guide, and the heat radiation effect of the stator is improved.

FIG. 2 is a schematic sectional view when the outer rotor type motor according to the first embodiment of the present invention is configured as an in-wheel motor. It is a perspective view of the bobbin used for the outer rotor type motor which concerns on one Embodiment of this invention. FIG. 3 is a diagram showing the bobbin shown in FIG. 2 viewed from each direction and a diagram showing a cross section. FIG. 3 is a perspective view showing a state in which a bobbin is mounted on a stator in the outer rotor type motor according to one embodiment of the present invention. FIG. 3 is a cross-sectional view illustrating a state in which a stator center and a stator guide are mounted on a stator core in one embodiment of the present invention.

Hereinafter, preferred embodiments of the outer rotor type motor and the electric vehicle according to the present invention will be described with reference to the drawings. In the following description, configurations denoted by the same reference numerals in different drawings are the same, and description thereof may be omitted. It should be noted that the present invention is not limited to the exemplifications of these embodiments, but includes all changes within the scope of the matters described in the claims and within the equivalent scope. Further, the present invention includes a combination of any of the embodiments, as long as a combination of a plurality of embodiments is possible.

In the following description, the outer rotor type motor will be described as an example of an in-wheel motor mounted in a wheel of a vehicle. FIG. 1 is a schematic cross-sectional view when the outer rotor type motor according to the first embodiment of the present invention is configured as an in-wheel motor, and is partially simplified. The wheels and tires of the vehicle are not shown.

The in-wheel motor 100 is built in the wheel of the electric vehicle, and is arranged on the same axis as the axis of the wheel. As shown in FIG. 1, the in-wheel motor 100 has a hub shaft 11, and a wheel (not shown) is mounted by a wheel mounting hub bolt 16 protruding from a wheel mounting surface. For this reason, steel is used for the hub shaft 11 from the viewpoint of securing the strength of mounting the wheels of the vehicle. A brake clamp 18 is also fixed to the hub shaft 11. The hub shaft 11 is rotatably supported by a bearing support member 26 via a bearing 17. The bearing 17 has an inner race 17a, an outer race 17b, and a plurality of rolling elements 17c provided between the inner race 17a and the outer race 17b. The bearing support member 26 is fixed by a bolt 27 to a knuckle which is an underbody frame part (not shown) on the vehicle body side. The bearing support member 26 is made of steel in the same manner as the hub shaft 11 from the viewpoint of securing strength for mounting the in-wheel motor 100 on the vehicle body side. Thereby, the in-wheel motor 100 is attached to the vehicle body (not shown), and the hub shaft 11 is rotatable with respect to the vehicle body. The hub shaft 11 is arranged on the same axis as the axis of the wheel.

ロータ A rotor case 12 is fixed to the hub shaft 11. The rotor case 12 has a side surface portion 12a that covers the side surface of the in-wheel motor 100 on the wheel mounting side, and a peripheral portion 12b that extends in the axial direction from the side surface portion 12a. It is desirable to use aluminum for the rotor case 12 in terms of weight reduction and heat conduction. A groove is formed in the inner peripheral surface of the peripheral portion 12b of the rotor case 12, and a cylindrical rotor core 13 made of a magnetic material is disposed inside the groove. For example, a plurality of grooves are formed on the inner peripheral surface of the rotor core 13, and the rotor magnet 14 is fixed in an annular shape in the grooves. As the rotor magnet 14, it is desirable to use a neodymium magnet having a strong magnetic force.

ステータ A stator core 21 is arranged on the inner peripheral surface side of the annularly arranged rotor magnets 14 with a predetermined gap therebetween. The stator core 21 has an annular base 21a and a plurality of teeth 21b radially protruding from the annular base 21a, and is composed of a laminated body of electromagnetic steel sheets. The teeth 21b are formed in a substantially rectangular parallelepiped shape. A bobbin 30 around which a stator coil 40 is wound is fixed to each tooth 21b of the stator core 21.

ステータ A stator center 22 and a stator guide 23 that support the stator core 21 are provided on the inner peripheral side of the stator core 21, and the stator center 22 is fixed to a bearing support member 26. The stator center 22 and the stator guide 23 are members for supporting the stator core 21, and have holding

pieces

22 a and 23 a that sandwich and hold the stator core 21 from both sides in the axial direction. The stator center 22 and the stator guide 23 are fixed by bolts 24 provided on the inner diameter side of the stator core 21 in a state where the inner peripheral surface of the stator core 21 and both end surfaces in the axial direction are positioned. The fixing structure of the stator core 21 will be described later. The stator center 22 and the stator guide 23 are made of aluminum having a high thermal conductivity. A wiring bus 25 is provided on the axial side surface of the stator coil 40, and the winding end 41 of the stator coil 40 is connected outside the wiring bus 25.

ロータ The bearing support member 26 or the stator center 22 is provided with a rotor position detection sensor 50 composed of, for example, a resolver for detecting the rotational position of the rotor. The rotor position signal from the rotor position detection sensor 50 is sent to a control circuit of a motor driving inverter (not shown). The inverter switches a DC power supply by a switching element according to the position of the rotor, converts the DC power into, for example, three-phase AC, and supplies a current to each stator coil 40 through the current supply line 60 and the wiring bus 25.

モータ A motor cap 15 is provided on the peripheral edge 12b of the rotor case 12 to cover the opposite side of the wheel mounting surface. In the present embodiment, the motor cap 15 faces the stator center 22 via the oil seal 19. In the present embodiment, it is possible to prevent water and dust from entering the in-wheel motor 100.

In the in-wheel motor 100 according to the present embodiment, the bearing support member 26, the stator core 21, the bobbin 30, the stator coil 40, the stator center 22, and the stator guide 23 are fixed members that do not rotate. It is attached. Further, the hub shaft 11, the rotor case 12, the rotor core 13, the rotor magnet 14, and the motor cap 15 serve as rotating members. Since the rotor magnet 14 is located outside the stator core 21, the in-wheel motor 100 of the present embodiment constitutes an outer rotor type motor. The wheel of the electric vehicle rotates at the same speed as the rotor of the in-wheel motor 100.

Next, the structure of the bobbin 30 in the present embodiment will be described. FIG. 2 is a perspective view of a bobbin used for the outer rotor type motor according to one embodiment of the present invention. 3A and 3B are a view and a cross-sectional view of the bobbin shown in FIG. 2 when viewed from each direction. In FIG. 3, FIG. 3A is a bottom view of the bobbin, FIG. 3C is a front view of the bobbin, and FIG. 3D is a cross-sectional view taken along a line DD in FIG. 3A. In the following description, the positional relationship of each part of the bobbin 30 will be described on the assumption that the bobbin 30 is mounted on the teeth 21 b of the stator core 21. In the bobbin 30 shown in FIG. 3, the X-axis direction is the radial direction, the positive direction side is the outer diameter side, and the negative direction side is the inner diameter side. The Y-axis direction and the Z-axis direction are the circumferential direction and the axial direction of the outer rotor type motor, respectively.

The bobbin 30 is molded from synthetic resin, glass fiber reinforced resin, or the like, and has a body 31 and two flanges at both ends of the body 31, an outer flange 32 and an inner flange 33. ing. The inside of the body portion 31 is a hollow portion 31a formed in a hollow shape, and the cross-sectional shape is substantially equal to the cross-sectional shape of the teeth 21b of the stator core 21. When the bobbin 30 is mounted on the teeth 21b of the stator core 21, the teeth 21b are inserted into the hollow portions 31a. A stator coil 40 is wound around the body 31. A cutout 33a into which the winding end 41 of the stator coil 40 is inserted is provided at a location on the inner side flange portion 33 on the wiring bus 25 side in the axial direction.

A first engaging portion 34 and a second engaging portion 35 for preventing the bobbin 30 from moving in the radial direction from the stator core 21 are provided on both sides of the inner diameter side flange portion 33 further on the inner diameter side in the axial direction. Have been. The interval between the first engagement portion 34 and the second engagement portion 35 is formed to be substantially equal to the axial thickness of the stator core 21. The circumferential width of the first engaging portion 34 and the second engaging portion 35 is substantially equal to the circumferential width of the inner diameter side flange portion 33 as shown in FIGS. It has a width.

The first engagement portion 34 is provided with an engagement hole 34a into which an engagement piece 22c provided in the stator center 22 described later is inserted. The engagement hole 34a penetrates in the axial direction, and when the bobbin 30 is mounted on the teeth 21b of the stator core 21, the stator core 21 is exposed through the engagement hole 34a. On the inner diameter side of the engagement hole 34a of the first engagement portion 34, a projection 34b projecting outward in the axial direction is provided. The protrusion 34b prevents the bobbin 30 from moving in the radial direction from the stator core 21 together with the engagement hole 34a when the inner diameter surface of the engagement piece 22c of the stator center 22 abuts on the outer diameter surface. It has a function to prevent it.

The second engagement portion 35 is provided with an engagement hole 35a into which an engagement piece 23c provided in the stator guide 23 described later is inserted. The engagement hole 35a penetrates in the axial direction, and when the bobbin 30 is mounted on the teeth 21b of the stator core 21, the stator core 21 is exposed through the engagement hole 35a. On the inner diameter side of the engagement hole 35a of the second engagement portion 35, a projection 35b projecting outward in the axial direction is provided. The protrusion 35b prevents the bobbin 30 from moving in the radial direction from the stator core 21 together with the engagement hole 35a when the inner diameter surface of the engagement piece 23c of the stator guide 23 contacts the outer diameter surface. It has a function to prevent it.

Next, the structure for fixing the bobbin 30 and the stator core 21 in the present embodiment will be described. FIG. 4 is a perspective view showing how a bobbin is mounted on a stator core in the outer rotor type motor according to one embodiment of the present invention. FIG. 5 is a cross-sectional view showing a state in which a stator center and a stator guide are mounted on a stator according to an embodiment of the present invention. FIG. 5A is a cross-sectional view of a tooth portion on which a bobbin is mounted. FIG. 5 (B) shows a cross section at a location where the bobbin is not mounted. As described above, the stator core 21 includes the annular base 21a and the teeth 21b radially protruding from the annular base 21a. Although FIG. 4 shows only one bobbin around which a coil is wound, a bobbin 30 around which a stator coil 40 is wound is mounted on each tooth 21b. On the stator center 22 and the stator guide 23, holding

pieces

22a and 23a for holding the stator core 21 from both sides in the axial direction are formed, respectively.

The holding piece 22a of the stator center 22 covers the axial end face of the projection 34b of the first engagement portion 34 of the bobbin 30, and the annular portion 22b located on the outer periphery of the stator center 22 and the bobbin 30 are mounted on the stator core 21. In this case, a plurality of engagement pieces 22c are integrally provided that protrude in the axial direction from the outer diameter side of the annular portion 22b toward the engagement hole 34a of the first engagement portion 34 of the bobbin 30. The holding piece 23a of the stator guide 23 covers an axial end face of the projection 35b of the second engaging portion 35 of the bobbin 30 and an annular portion 23b located on the outer peripheral portion of the stator guide 23. A plurality of engaging pieces 23c are integrally provided that project in the axial direction from the outer diameter side of the annular portion 23b toward the engaging hole 35a of the second engaging portion 35 of the bobbin 30 when mounted on the bobbin 30. .

In fixing the bobbin 30 and the stator core 21, first, the bobbin 30 on which the stator coil 40 is wound is mounted on all the teeth 21 b of the stator core 21. Next, the stator core 21 is placed on the stator center 22. At this time, the engagement pieces 22 c of the stator center 22 are inserted into the engagement holes 34 a of the first engagement portions 34 of the bobbin 30. Next, the stator core 21 is positioned. Next, the stator guide 23 is placed on the upper part of the stator core 21. At this time, the stator guide 23 is positioned so that the engagement pieces 23c of the stator guide 23 are inserted into the respective engagement holes 35a of the bobbin 30.

After the positioning of the stator core 21, the stator center 22, and the stator guide 23 is completed, the stator center 22 and the stator guide 23 are fixed by the bolts 24. In this state, the tip of the engagement piece 22c of the stator center 22 and the tip of the engagement piece 23c of the stator guide 23 directly contact the stator core 21 to position the stator core 21 in the axial direction. Further, the annular portion 22b of the stator center 22 does not press the axial end surface of the projection 34b of the first engagement portion 34 of the bobbin 30, and the annular portion 23b of the stator guide 23 is The dimensions of each member are determined so that the axial end surface of the protrusion 35b of the second engaging portion 35 is not pressed.

The stator core 21 is axially positioned and held by the engaging pieces 22c of the stator center 22 and the engaging pieces 23c of the stator guide 23. The inner surface of the engagement piece 22c of the stator center 22 contacts the inner surface of the engagement hole 34a of the first engagement portion 34 of the bobbin 30. The inner surface of the bobbin 30 contacts the inner surface of each of the engagement holes 35a of the bobbin 30, so that the bobbin 30 does not move in the radial direction from the stator core 21.

As described above, in the present embodiment, the pressing force is not directly applied to the bobbin 30 made of the resin material from the stator center 22 or the stator guide 23. Further, even if the bobbin 30 repeatedly expands and contracts due to heat generation from the stator coil 40 due to the stoppage of the operation of the outer rotor type motor, no force is applied to the bobbin 30 from the stator center 22 or the stator guide 23. Then, the heat from the stator core 21 is transmitted to the stator center 22 via the engagement pieces 22c of the stator center 22 and the engagement pieces of the stator guide 23. Therefore, the heat radiation effect of the stator core 21 is improved. The stator core 21 may be positioned by the stator center 22 and other portions of the stator guide in addition to the engagement pieces 22c of the stator center 22 and the engagement pieces 23c of the stator guide 23.

In the present embodiment, the radial length of the first engaging portion 34 of the bobbin 30 on the wiring bus 25 side is configured to be longer than the length of the second engaging portion 35. As a result, as shown in FIG. 1, a part of the wiring bus 25 can be brought into contact with the engaging piece 22c of the stator center 22, so that the positioning of the wiring bus 25 in the radial direction becomes possible.

Furthermore, whether or not the protrusion 34b of the first engagement portion 34 and the protrusion 35b of the second engagement portion 35 are provided according to the strength required to prevent the bobbin 30 from coming off the stator core 21 is determined. You can choose. The shape of the holding piece 22a of the stator center 22 and the holding piece 23a of the stator guide 23 also depends on the presence or absence of the protrusion 34b of the first engagement portion 34 and the protrusion 35b of the second engagement portion 35. What is necessary is just to change the shape. For example, when the projection 34b of the first engagement portion 34 is not provided, the annular portion 22b of the holding piece 22a of the stator center 22 has a shape that covers the axial end surface of the first engagement portion 34 of the bobbin 30. The annular portion 23b of the holding piece 23a of the stator guide 23 has a shape that covers the axial end surface of the second engagement portion 35 of the bobbin 30.

As described above, when the outer rotor type motor of the present invention is used as an in-wheel motor, all or most of the outer rotor type motor can be housed in the wheel of an electric vehicle. Also, even outside the wheel, the wheel of the electric vehicle can be directly driven without interposing a gear or the like by arranging the outer rotor type motor on the same axis as the wheel. Further, the outer rotor type motor of the present invention can be applied to other uses than electric vehicles.

DESCRIPTION OF SYMBOLS 11 ... Hub shaft, 12 ... Rotor case, 12a ... Side surface part, 12b ... Peripheral part, 13 ... Rotor core, 14 ... Rotor magnet, 15 ... Motor cap, 16 ... Wheel mounting hub bolt, 17 ... Bearing, 17a ... Inner ring, 17b ... outer ring, 17c ... rolling element, 18 ... brake clamp, 19 ... oil seal, 21 ... stator core, 21a ... annular base, 21b ... teeth, 22 ... stator center, 22a ... holding piece, 22b ... annular part, 22c ... engagement Pieces, 23: stator guide, 23a: holding piece, 23b: annular portion, 23c: engaging piece, 24: bolt, 25: wiring bus, 26: bearing support member, 27: bolt, 30: bobbin, 31: trunk 31a: hollow portion, 32: outer diameter side flange portion, 33: inner diameter side flange portion, 33a: notch, 34: first engagement portion, 34a: engagement hole, 34b: projection portion, 5 ... second engaging portion, 35a ... engagement hole, 35b ... protrusion, 40 ... stator coil, 41 ... winding end, 50 ... rotor position detection sensor, 60 ... current supply line, 100 ... in-wheel motor.

Claims

A stator core having a plurality of teeth radially on the outer diameter side of the annular base;
A stator center and a stator guide for positioning the stator core from both sides in the axial direction;
An outer rotor type motor having a bobbin around which a coil is wound and attached to the teeth of the plurality of stator cores,
On both sides in the axial direction on the inner diameter side of the bobbin, there is provided an engaging portion projecting with an engaging hole penetrating in the axial direction,
A plurality of engagement pieces projecting in the axial direction are provided on respective outer peripheral portions of the stator center and the stator guide,
In a state where the bobbin is mounted on the stator core, the engagement pieces of the stator center and the stator guide are inserted into the engagement holes of the bobbin, and a tip of the engagement piece is an axial end face of the stator core. Wherein the stator core is positioned in the axial direction by contact with the outer rotor type motor.
The bobbin has two flanges spaced apart in the radial direction in a state where the bobbin is mounted on the stator core, and a winding end of the coil is inserted into a position on the axial side of the flange on the inner diameter side. The outer rotor type motor according to claim 1, wherein the outer rotor type motor has a notch formed.
An electric vehicle, wherein the outer rotor type motor according to claim 1 or 2 is provided on a wheel of a wheel, and the wheel is directly driven by the outer rotor type motor.