JP5030209B2 - In-wheel motor unit - Google Patents

Description

  The present invention relates to an in-wheel motor unit that drives driving wheels of a vehicle.

  In a conventional electric vehicle, torque is transmitted from one electric motor arranged on a vehicle body to wheels via a transmission and a differential mechanism. However, according to this method, there is a problem that a space for providing the electric motor, the transmission, and the differential mechanism is required, and the space for the occupant is limited accordingly. In addition, since a power transmission loss occurs in the transmission and the differential mechanism, there is a problem in that the torque transmitted to the wheels is reduced accordingly.

On the other hand, Patent Document 1 below discloses an outer rotor type wheel motor in which a motor is provided inside the wheel. According to such a wheel motor, since the motor can be built in the wheel, there is no need to mount an electric motor, a transmission, and a differential mechanism on the vehicle body, and a space for passengers can be secured, and no transmission or differential mechanism is used. There is an advantage that power transmission loss is reduced.
Japanese Patent Laid-Open No. 10-285891

  By the way, in a motor unit in which a stator is arranged on the vehicle body side, a rotor is arranged on the wheel side, and the stator and the rotor are superposed in the radial direction, when a cornering force acts on the wheel, the moment force is reduced. Since it acts on the rotor, a phenomenon occurs in which the axis of the rotor is inclined with respect to the axis of the stator. In such a case, if the gap between the stator and the rotor is small, they may interfere with each other to generate abnormal noise or cause damage. On the other hand, if the gap between the stator and the rotor is increased, the interference between the two can be avoided, but another problem arises that the output of the motor unit is reduced accordingly.

  The present invention has been made in view of the problems of the related art, and an object thereof is to provide an in-wheel motor unit capable of suppressing interference between a stator and a rotor while maintaining motor performance. To do.

The in-wheel motor unit of the first invention is
A stator fixed to the vehicle body side, and a rotor attached together with the wheel of the wheel with the end side cantilevered via a rotor support plate with respect to a hub rotatably supported by the vehicle body ; An in-wheel motor unit in which at least a part of the stator and the rotor is disposed radially inward of the wheel,
One of the stator and the rotor is disposed radially inward of the other, and the outer diameter of the one increases from the end in the axial direction toward the center. .

The in-wheel motor unit of the second invention is
A stator fixed to the vehicle body side, and a rotor attached together with the wheel of the wheel with the end side cantilevered via a rotor support plate with respect to a hub rotatably supported by the vehicle body ; An in-wheel motor unit in which at least a part of the stator and the rotor is disposed radially inward of the wheel,
One of the stator and the rotor is arranged inside the other in the radial direction, and the other inner diameter decreases from the end in the axial direction toward the center.

  According to the in-wheel motor unit of the first aspect of the present invention, one of the stator and the rotor is disposed radially inward of the other, and the outer diameter of the one is on the axial end side. As the wheel is subjected to a cornering force from the corner to the center, even if a moment is applied to the rotor and its axis is inclined, the end of the stator and the rotor in the axial direction is increased. It is possible to suppress contact between the parts, and thus to prevent problems such as abnormal noise.

  Further, it is preferable that the one has a substantially spherical outer peripheral surface. However, the present invention is not limited to this. For example, a tapered surface or the like may be formed on the end side.

  According to the in-wheel motor unit of the second aspect of the present invention, one of the stator and the rotor is disposed on the other radial inner side, and the other inner diameter is from the axial end side. Since it becomes smaller toward the center, even if a moment is applied to the rotor due to the cornering force of the wheel and the axis thereof is inclined, the end portions in the axial direction of the stator and the rotor It is possible to suppress contact between each other, and thus it is possible to prevent problems such as abnormal noise.

  Further, it is preferable that the other has a tapered inner peripheral surface. However, the present invention is not limited to this, and for example, a substantially spherical surface or the like may be formed on the end side.

  The stator and the rotor are preferably arranged in a cylindrical shape coaxial with the wheel.

  Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a perspective view of a bus on which an in-wheel motor unit according to the present embodiment is mounted. In FIG. 1, a pair of in-wheel motor units 100 is attached to a bus body 101 via a bracket (not shown).

  Wheels 103 are arranged around each in-wheel motor unit 100 and are driven by the in-wheel motor unit 100. An inverter unit 104 is disposed below the vehicle body 101 and is electrically connected to the in-wheel motor unit 100 via the wiring 13. Inverter unit 104 has a flat shape in the present embodiment, and therefore, even if it is provided in the lower part of vehicle body 101, the space for passengers is not limited, but may be arranged on the ceiling of vehicle body 101. Thus, by using the in-wheel motor unit 100, the drive source can be accommodated in the wheel 103, and the position of the inverter unit 104 can be arbitrarily determined. This makes it possible to improve boarding / exiting performance and to secure passenger space.

  FIG. 2 is a cross-sectional view of the in-wheel motor unit 100 shown with the wheels 103 attached. Hereinafter, only one in-wheel motor unit 100 will be described, but the other in-wheel motor unit 100 has the same configuration.

  In FIG. 2, a hub bearing unit 2 is fixed to a vehicle body via a bracket 1. The hub bearing unit 2 rotatably supports a hub 3 included therein. A brake disk 4, a disk-shaped rotor support plate 5, and a wheel 6 are arranged on the hub 3 coaxially from the inside in this order and fixed by bolts. The brake disk 4 is brought into contact with a pad provided on a brake device (not shown), thereby generating a braking force. A wheel 7 is attached around the wheel 6.

  A rotor 8 is attached to the outer edge of the rotor support plate 5. The rotor 8 includes a cylindrical rotor core 8a made of a silicon steel plate, and a rotor holder 8b that holds the rotor core 8a from both sides in the axial direction while exposing the inner peripheral surface thereof. The rotor holder 8b These axial ends are fixed to the rotor support plate 5 with bolts.

  On the other hand, a stator support plate 9 is fixed to the hub bearing unit 2 with bolts. A stator 10 is attached to the outer edge of the stator support plate 9. The stator 10 includes a plurality of stator cores 10a arranged to face the inner side in the radial direction of the rotor core 8a, a coil 10b around which the stator core 10a is wound, a stator core 10a, and an outer peripheral surface thereof. It consists of a stator holder 10c that is held from both sides in the axial direction while being exposed, and a fixing member 10d that fixes the stator core 10a on the wheel 6 side. The axial end of the stator holder 10c is fixed to the stator support plate 9 with bolts. The gap between the rotor core 10a and the stator core 8a is 0.5 to 2 mm.

  A seal member 11 is disposed between the fixed member 10d and the rotor holder 8b. Further, on the bracket 1 side, the rotor holder 8b forms an inner flange portion 8c extending radially inward, and the stator holder 10c extends radially outward adjacent to the inner flange portion 8c. An outer flange portion 10h is formed. Thus, dust or the like is prevented from entering between the rotor core 8a and the stator core 10a.

  FIG. 3 is a perspective view showing a part of the stator. On the outer peripheral surface of the cylindrical stator holder 10c, dovetail grooves 10e extending in the axial direction are formed at equal intervals by the number of stator cores 10a. The stator core 10a made of a silicon steel plate has a T shape when viewed in the axial direction, and the lower end in FIG. 3 is a reverse tapered portion 10f corresponding to the dovetail groove 10e. Further, the outer surface 10g of the stator core 10a is a part of an outer convex spherical surface. That is, in the axial direction of the stator holder 10c, the outer surface 10g has the largest outer diameter φA at the center, and then becomes smaller toward both sides in the axial direction, and the outer diameter φB at the end of the stator core 10a becomes the smallest. . The stator core 10a can be formed with the same precision as the same component by machining or sintering of magnetic powder.

  At the time of assembly, with the coil 10b wound around the stator core 10a as shown in FIG. 3, the dovetail groove 10e of the stator holder 10c is aligned with the reverse tapered portion 10f, and the stator core 10a is attached to the stator holder 10c. Then, the fixing member 10d is fixed to the stator holder 10c (see FIG. 2). Thereby, the stator core 10a is attached to the stator holder 10c.

  The operation of this embodiment will be described. For example, when the driver depresses an accelerator pedal (not shown), a high-frequency current is transmitted from the inverter unit 104 to the coil 10 b of the stator 10 via the wiring 13 in conjunction with the accelerator pedal. The wheel 7 can be rotationally driven by rotating the wheel 6 using such magnetic force.

  Furthermore, even if the wheel 7 receives a cornering force during turning and a moment is applied to the rotor 8 and its axis is inclined, the outer diameter of the stator core 10a is directed from the axial end to the center. Therefore, the contact between the end portions in the axial direction of the stator 10 and the rotor 8 can be suppressed, so that problems such as abnormal noise can be prevented. In addition, since the stator 10 and the rotor 8 are arranged on the inner side in the radial direction of the wheel 7, a compact configuration can be provided.

  FIG. 4 is a cross-sectional view similar to FIG. 2 according to another embodiment. In the embodiment shown in FIG. 4, the outer surface of the stator core 10a is a cylindrical surface or a flat surface with respect to the above-described embodiment, and the inner peripheral surface of the rotor core 8 is centered from the end in the axial direction. It is machined into a tapered shape so that it becomes smaller in diameter. Since other points are the same as those in the above-described embodiment, description thereof is omitted.

  Also in the present embodiment, even if the wheel 7 receives a cornering force during turning and a moment is applied to the rotor 8 and the axis thereof is inclined, the inner diameter of the rotor core 8a is the end side in the axial direction. Therefore, the contact between the end portions in the axial direction of the stator 10 and the rotor 8 can be suppressed, so that troubles such as abnormal noises can be prevented. In the present embodiment, the stator core 10a may have the shape shown in FIG.

  As described above, the present invention has been described in detail with reference to the embodiments. However, the present invention should not be construed as being limited to the above-described embodiments, and can be appropriately changed and improved without departing from the spirit thereof. Of course there is. For example, the rotor may be disposed on the radially inner side of the stator, and the in-wheel motor of the present invention is used by a person other than a bus.

It is a perspective view of the bus carrying the in-wheel motor unit concerning this embodiment. It is sectional drawing of the in-wheel motor unit 100 shown in the state which attached the wheel. It is a perspective view which shows a part of stator. It is sectional drawing similar to FIG. 2 concerning another embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Bracket 2 Hub bearing unit 3 Hub 4 Brake disk 5 Rotor support plate 6 Wheel 7 Wheel 8 Rotor 8a Rotor core 8b Rotor holder 8c Inner flange part 9 Stator support plate 10 Stator 10a Stator core 10b Coil 10c Stator holder 10d Fixing member 10e Dovetail groove 10f Reverse taper portion 10g Outer surface 10h Outer flange portion 11 Seal member 13 Wiring 100 In-wheel motor unit 101 Car body 103 Wheel 104 Inverter unit

Claims (5)

A stator fixed to the vehicle body side, and a rotor attached together with the wheel of the wheel with the end side cantilevered via a rotor support plate with respect to a hub rotatably supported by the vehicle body ; An in-wheel motor unit in which at least a part of the stator and the rotor is disposed radially inward of the wheel,
One of the stator and the rotor is disposed radially inward of the other, and the outer diameter of the one increases from the end in the axial direction toward the center. In-wheel motor unit.   The in-wheel motor unit according to claim 1, wherein the one has a substantially spherical outer peripheral surface. A stator fixed to the vehicle body side, and a rotor attached together with the wheel of the wheel with the end side cantilevered via a rotor support plate with respect to a hub rotatably supported by the vehicle body ; An in-wheel motor unit in which at least a part of the stator and the rotor is disposed radially inward of the wheel,
One of the stator and the rotor is disposed radially inward of the other, and the inner diameter of the other decreases from the end in the axial direction toward the center. Wheel motor unit.   The in-wheel motor unit according to claim 3, wherein the other has a tapered inner peripheral surface.   The in-wheel motor unit according to any one of claims 1 to 4, wherein the stator and the rotor are arranged in a cylindrical shape coaxial with the wheel.

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