JP4260462B2 - In-wheel motor system - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an in-wheel motor system used in a vehicle using a direct drive wheel as a driving wheel.
[0002]
[Prior art]
In recent years, an in-wheel motor system in which a motor is built in a wheel is being adopted in a vehicle driven by a motor such as an electric vehicle. By the way, in the conventional in-wheel motor, the motor part is fixed to a spindle shaft connected to a part called an upright or a knuckle which is one of the parts constituting the undercarriage of the vehicle, and the motor rotor and the wheel can rotate. (For example, see Patent Documents 1 to 3).
In general, in a vehicle having a suspension mechanism such as a spring around the undercarriage, the larger the mass of the unsprung parts such as wheels, knuckles, and suspension arms, the larger the so-called unsprung mass, It is known that the fluctuation of force increases and the load holding property deteriorates.
[0003]
On the other hand, in a vehicle driven by a motor such as an electric vehicle, an in-wheel motor with a built-in motor in a wheel may be employed because of high space efficiency and driving force transmission efficiency. However, in the conventional in-wheel motor, as described above, since the motor stator portion is rotatably fixed to the spindle shaft connected to the undercarriage part of the vehicle, the unsprung mass is increased by the amount of the in-wheel motor. As a result, there is a problem that the tire contact force fluctuation increases and the road holding performance deteriorates.
[0004]
In order to solve the above problem, as shown in FIG. 5, the non-rotating side case 3a that supports the stator 3S of the hollow in-wheel motor 3 and the knuckle 5 are guided in the vertical direction of the vehicle. The linear guide member 11 is connected by a buffer mechanism 10 including a shock absorber 12 made of a damper and a spring member that expands and contracts in the operating direction of the linear guide member 11, and supports the rotor 3R of the motor 3. An in-wheel motor system having a configuration in which the rotating case 3b and the wheel 2 are coupled by a flexible coupling 20 that is a driving force transmission mechanism has been proposed. As a result, the motor 3 is elastically supported with respect to the knuckle 5 that is an undercarriage part of the vehicle, and the torque can be efficiently transmitted to the wheel 2 and restrained in the vertical movement direction. It is possible to improve the road holding performance of the vehicle by reducing the fluctuation of the ground contact force.
As shown in FIG. 6 (a), the flexible coupling 20 couples a plurality of hollow disk-shaped plates 21A to 21C to the adjacent plates 21A and 21B and the plates 21B and 21C. The linear movement guides 22A and 22B are provided with the adjacent plates 21A and 21B and the plates 21B and 21C that guide each other in the radial direction of the disk. As the linear movement guides 22A and 22B, for example, FIG. As shown in FIG. 5, the guide rail 22p having a convex portion extending in the radial direction of the plates 21A to 21C and the guide rail 22p having a concave portion extending in the radial direction of the plates 21A to 21C and engaging with the guide rail 22p. The member 22q, the guide rail 22p, and the guide member 22q are slid more smoothly. To, composed of a plurality of steel balls 22m disposed between the recess of the projection and the guide member 22q of the guide rail 22p.
The guide rail 22p and the guide member 22q slide so as to guide the adjacent plates 21A and 21B and the plates 21B and 21C to each other in the radial direction of the disk, so that the in-wheel motor 3 is connected to the linear motion guides 22A and 22B. Although it can move along the operating direction, that is, the radial direction of the disk, it cannot move in the rotational direction, so that it is possible to efficiently transmit rotational torque to the wheel 2 (for example, Patent Documents). 4).
[0005]
7 and 8, as a driving force transmission mechanism, instead of the linear motion guides 22A and 22B, a motor 3 side and a wheel of an intermediate hollow disk-like plate (hereinafter referred to as an intermediate plate) 21B. A configuration using a flexible coupling 20Z in which a plurality of linear motion guides 23 and 24 are arranged at the same positions on the front and back sides of the plate at intervals of 90 ° on the circumferences of the two sides is also proposed. . In the flexible coupling 20Z, the operating direction of the linear guide 23 that is configured by the guide rail 23a and the guide member 23b and is disposed on the motor 3 side is set with respect to the radial direction of each of the hollow disk-shaped plates 21A to 21C. The operating direction of the linear guide 24 arranged on the wheel 2 side, which is composed of the guide rail 24a and the guide member 24b, is a direction orthogonal to the operating direction of the linear guide 24. .
By the way, in the flexible coupling 20, since there is no linear motion guide at the same position on the front and back of the intermediate plate 21B, the linear motion guides 22A and 22B are offset with respect to the circumferential direction of the hollow disk-shaped plates 21A to 21C. There is a risk of buckling deformation in the part that receives compressive load in the direction. In contrast, by adopting a configuration such as the flexible coupling 20Z, only the rotational force is transmitted from the in-wheel motor 3 to the plate 21C on the wheel 2 side. Can be transmitted reliably. Moreover, since the offset of the load in the circumferential direction of the intermediate plate 21B can be eliminated, the risk of buckling is reduced (see, for example, Patent Document 4).
[0006]
[Patent Document 1]
Japanese Patent No. 2676025 (2nd page, FIG. 1)
[Patent Document 2]
JP-T 9-506236 (page 9-12, FIG. 1)
[Patent Document 3]
Japanese Patent Laid-Open No. 10-305735 (page 3, FIG. 1)
[Patent Document 4]
International Publication No. 02/83446 Pamphlet [0007]
[Problems to be solved by the invention]
However, in the flexible coupling 20Z having the above-described configuration, when there is a disturbance, the intermediate plate 21B rotates while being eccentric, so that the motor 3 vibrates due to the vibration. In addition, it is necessary to provide a predetermined clearance in the wheel in view of the eccentricity of the intermediate plate 21B.
Furthermore, the operation direction of one of the linear motion guides 23 and 24 is set to 45 ° with respect to the radial direction of the intermediate plate 21B, and the other operation direction is set at the same position on the front and back of the intermediate plate 21B. Since it must be arranged in a direction perpendicular to it, not only high accuracy is required for assembly, but also the angle between each linear guide 23 and linear guide 24 is likely to vary on the intermediate plate 21B. There was a problem.
In addition, since at least three hollow disk-shaped plates are required, there is a disadvantage that the weight of the driving force transmission mechanism increases and the inertia of the driving system increases.
[0008]
The present invention has been made in view of the conventional problems, and is a drive force transmission mechanism that is easy to assemble, can reduce vibrations transmitted to the motor, and can reduce the inertia of the drive system. An object is to provide an in-wheel motor system provided.
[0009]
[Means for Solving the Problems]
According to a first aspect of the present gun is stator side of the direct drive motor of a hollow shape provided in the wheel section with respect to part around the vehicle, which is supported through the elastic body and / or the damping mechanism a in-wheel motor system, and the rotating side casing and the wheel of the motor rotor of the motor is mounted, and the wheel-side plate attached to the wheel, and a motor side plate connected to the rotary side casing, the rotor The cross guides are connected by a flexible coupling having a plurality of cross guides arranged at equal intervals in the circumferential direction and connecting the two plates, and the cross guide includes a motor side guide rail, a wheel side guide rail, and the above The guide groove for guiding the motor side guide rail and the extending direction of the guide groove for guiding the motor side guide rail A cross guide body having a guide groove extending in a direction to guide the wheel side guide rail, the motor side guide rail being attached to the motor side plate, and the wheel side guide rail being the wheel side plate The guide groove for guiding the motor side guide rail is provided on the motor side guide rail side of the cross guide body, and the guide groove for guiding the wheel side guide rail is the wheel side guide of the cross guide body. It is provided on the rail side . As a result, the operating directions of the front and back guide members can be reliably regulated and the drive transmission mechanism can be reduced in weight, so that the inertia of the drive system can be reduced. In addition, vibration transmitted to the motor can be reduced by reducing the weight.
According to a second aspect of the present invention, in the in-wheel motor system according to the first aspect, the motor side guide rail of the cross guide has an operating direction of 45 ° with respect to the radial direction of the motor rotor. And the cross guide is arranged so that all the operation directions of the wheel side guide rail are orthogonal to the operation direction of the motor side guide rail. Can be reliably suppressed, and only the rotational force can be transmitted to the wheel side.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a diagram showing a configuration of an in-wheel motor system according to the present embodiment, in which 1 is a tire, 2 is a wheel composed of a rim 2a and a wheel disc 2b, and 3 is an inner side in the radial direction. A motor stator (hereinafter referred to as a stator) 3S fixed to the non-rotating side case 3a provided on the outer side, and provided on the outer side in the radial direction and rotatable with respect to the non-rotating side case 3a via a bearing 3j This is an outer rotor type in-wheel motor provided with a motor rotor (hereinafter referred to as a rotor) 3R fixed to a rotating side case 3b joined to the rotor.
4 is a hub portion connected to the wheel 2 and its rotating shaft, 5 is a knuckle connected to the upper and lower suspension arms 6a and 6b, 7 is a suspension member composed of a shock absorber, and the like is attached to the hub portion 4. The braking device 10 includes a linear motion guide member 11 that guides the vehicle in the vertical direction, and a shock absorber 12 that includes a spring member and a damper that extend and contract in the operation direction of the linear motion guide member 11. A buffer mechanism for connecting the rotation side case 3a and the knuckle 5; 30 is a hollow disk-like motor side plate 31 attached to the rotation side case 3b of the motor; and a hollow disk-like wheel side plate 32 attached to the wheel 2 And a plurality of cross guides 33 for connecting the plates 31 and 32 to each other.
[0011]
As shown in FIG. 2, the cross guide 33 is a combination of two orthogonal linear motion guides, and is a beam-shaped member such as a motor-side guide rail 33 </ b> A, a wheel-side guide rail 33 </ b> B, and a rectangular parallelepiped member. And a cross guide body 33C provided with guide grooves 33a and 33b for guiding the guide rails 33A and 33B, respectively, provided on the upper and lower surfaces. Thereby, the motor side guide rail 33A and the wheel side guide rail 33B can operate in directions orthogonal to each other along the guide grooves 33a and 33b of the cross guide body 33C.
In this example, as shown in FIG. 3, four cross guides 33 are arranged at equal intervals (90 ° intervals) between the motor side plate 31 and the wheel side plate 32, and The motor side guide rails 33A are arranged such that their operating directions are all 45 ° with respect to the radial direction of the rotor 3R. Accordingly, the operating directions of the motor-side guide rails 33A are all in the same direction (45 ° direction), and all the operating directions of the wheel-side guide rails 33B are respectively relative to the operating directions of the motor-side guide rails 33A. The direction is orthogonal.
[0012]
In the above configuration, the rotational force from the rotation side case 3 b of the in-wheel motor 3 is first input to the motor side guide rail 33 </ b> A via the motor side plate 31. The circumferential force input to the motor side guide rail 33A is transmitted to the wheel side guide rail 33B through the cross guide body 33C to drive the wheel 2.
At this time, as shown in FIG. 4, the cross guide main body 33C has a force that rotates in the circumferential direction and a force that is pushed outward in the radial direction by an input from the motor side guide rail 33A and a reaction from the wheel side guide rail 33B. And act.
However, although the motor-side guide rail 33A and the wheel-side guide rail 33B move in the rotating direction, but always try to keep the directions orthogonal to each other, the force to push the cross guide 33 radially outward is: It is balanced with the twisting reaction force of the cross guide body 33C. As a result, since the eccentricity can be absorbed by only the plurality of cross guides 33, the torque from the rotor 3R can be smoothly transmitted to the wheel 2.
[0013]
As described above, according to this embodiment, the non-rotating side case 3a that supports the stator 3S of the in-wheel motor 3 is coupled by the buffer mechanism 10 so as to be swingable in the vehicle vertical direction. , The rotation side case 3b that supports the rotor 3R and the wheel 2 are arranged such that the operation directions of the motor side guide rails 33A are all 45 ° with respect to the radial direction of the rotor 3R, and all the operation directions of the wheel side guide rails 33B. Is coupled by a flexible coupling 30 having a plurality of cross guides 33 arranged so as to be orthogonal to the operating direction of the motor side guide rail 33A. The wheel 2 can be reliably transmitted.
In addition, since the intermediate plate can be omitted, the flexible coupling 30 can be reduced in weight, the vibration transmitted to the motor 3 can be greatly reduced, and the inertia of the drive system can be reduced, Since it is not necessary to provide a predetermined clearance in the wheel, the degree of design freedom can be increased.
Further, by using the cross guide 33, the operation direction of the motor side guide rail 33A and the wheel side guide rail 33B can be limited to the directions orthogonal to each other. The operation of the ring 30 can be stabilized.
[0014]
In the above embodiment, the case where the four cross guides 33 are used has been described. However, the number of the cross guides 33 is not limited to this, and is two, three, or five or more. Also good. At this time, the cross guides 33 are preferably arranged at equal intervals between the motor side plate 31 and the wheel side plate 32.
Further, the shape of the guide rails 33A and 33B of the cross guide 33 is not limited to the beam shape as shown in FIG. 3, but is a member having a convex portion that engages with the guide grooves 33a and 33b of the cross guide. There may be. Further, in order to slide the guide rails 33A and 33B more smoothly, a plurality of steel balls may be disposed between the guide grooves 33a and 33b and the convex portions of the guide rails 33A and 33B. Good.
[0015]
【The invention's effect】
As described above, according to the present invention, in the in-wheel motor system in which the stator side of the hollow direct drive motor is supported via the elastic body and / or the damping mechanism with respect to the underbody part of the vehicle, the motor a rotating side case and the wheel of the motor is the rotor mounted, and the wheel-side plate attached to the wheel, and a motor side plate connected to the rotating side case of the motor, are arranged at regular intervals in the rotor circumferential direction Since the two plates are connected by a flexible coupling having a plurality of cross guides whose operating directions are orthogonal to each other on the front and back, the operating direction of the front and back guide members can be reliably regulated and driven. Since the transmission mechanism can be reduced in size and weight, the inertia of the drive system can be reduced. In addition, the vibration transmitted to the motor can be significantly reduced by reducing the weight.
In addition, the motor side guide rails of the cross guides are arranged so that their operating directions are all 45 ° with respect to the radial direction of the motor rotor, and all the operating directions of the wheel side guide rails are By arranging the guide rail in a direction orthogonal to the operation direction of the guide rail, buckling deformation can be suppressed, and only the rotational force can be reliably transmitted to the wheel side.
Further, by adopting the in-wheel motor system of the present invention, it is possible to realize an in-wheel motor vehicle that is excellent in space efficiency and driving force transmission efficiency and has little fluctuation in tire ground contact force.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view showing a configuration of an in-wheel motor system according to an embodiment of the present invention.
FIG. 2 is a diagram showing a configuration of a cross guide according to the present embodiment.
FIG. 3 is a diagram showing a configuration example of a flexible coupling according to the present embodiment.
FIG. 4 is a diagram for explaining the operation of a flexible coupling.
FIG. 5 is a diagram showing a configuration of a conventional in-wheel motor.
FIG. 6 is a diagram showing a configuration of a conventional flexible coupling.
FIG. 7 is a diagram showing another configuration of a conventional in-wheel motor.
FIG. 8 is a view showing another configuration of a conventional flexible coupling.
[Explanation of symbols]
1 tire, 2 wheel, 2a rim, 2b wheel disc,
3 In-wheel motor, 3R motor rotor, 3S motor stator,
3a non-rotating side case, 3b rotating side case, 3j bearing, 4 hub part,
5 knuckle, 6a, 6b suspension arm, 7 suspension member,
8 braking device, 10 buffer mechanism, 11 linear motion guide member,
12 Shock absorber, 30 Flexible coupling,
31 Motor side plate, 32 Wheel side plate, 33 Cross guide,
33A Motor side guide rail, 33B Wheel side guide rail,
33C Cross guide body.

Claims (2)

Mounting the stator side of the direct drive motor of a hollow shape provided in the wheel section with respect to part around the vehicle, in-wheel motor system which is supported through the elastic bodies and / rotor of the motor is the rotation-side casing and the wheel of the motor, and the wheel-side plate attached to the wheel, and a motor side plate connected to the rotary side casing, are arranged at equal intervals in the rotor circumferential direction of the two plates It is connected by a flexible coupling having a plurality of cross guides to be connected,
The cross guide extends in a direction orthogonal to the motor side guide rail, the wheel side guide rail, the guide groove for guiding the motor side guide rail, and the extending direction of the guide groove for guiding the motor side guide rail. A cross guide body having a guide groove for guiding the wheel side guide rail,
The motor side guide rail is attached to the motor side plate,
The wheel side guide rail is attached to the wheel side plate,
A guide groove for guiding the motor side guide rail is provided on the motor side guide rail side of the cross guide body,
An in-wheel motor system, wherein a guide groove for guiding the wheel side guide rail is provided on the wheel side guide rail side of the cross guide body .   The cross-guide motor side guide rails are arranged so that their operating directions are all 45 ° with respect to the radial direction of the motor rotor, and all the operating directions of the wheel side guide rails are The in-wheel motor system according to claim 1, wherein the cross guide is disposed so as to be in a direction orthogonal to the operation direction.

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