JP2005170150A - Wheel motor supporting structure - Google Patents

Abstract

An object of the present invention is to improve riding comfort against harshness and the like while allowing eccentricity between a road wheel and a motor.
A motor 5 is housed in a case 1 supported by a suspension arm, and a plurality of fluid mounts 6 are evenly disposed between the outer periphery of the motor 5 and the case 1. By giving the fluid mount 6 the function of a spring and the function of a damper, a dynamic damper is constructed with the mass of the motor 5, and it is evenly arranged on the outer periphery of the motor 5. It is possible to effectively dampen the vibration to the. By inserting at least one or more universal joints 7 between the output shaft of the motor 5 and the axle 4, eccentricity between the load wheel and the motor is allowed, and the motor torque can be transmitted.
[Selection] Figure 2

Description

  The present invention relates to a wheel motor used in a vehicle, a so-called wheel-in motor support structure.

As such a wheel motor support structure, for example, when supporting a wheel motor with a speed reducer, a damper is disposed around the motor output shaft, and the output is obtained by sandwiching it between the flange and the hub. There is one that suppresses transmission of shaft vibration to a road wheel (for example, Patent Document 1).
JP-A-9-1332040

However, in the wheel motor support structure described in Patent Document 1, since the motor output shaft is sandwiched between the flange and the hub, the eccentricity between the output shaft and the load wheel is not allowed. There is a problem that the comfort gets worse.
The present invention has been developed to solve the above problems, and an object thereof is to provide a wheel motor support structure capable of improving riding comfort while allowing eccentricity between the motor and the load wheel. Is.

  In order to solve the above problems, the wheel motor support structure of the present invention elastically supports the motor on the vehicle body side member or the suspension device, and at the connection portion between the rotation shaft of the motor and the load wheel, the rotation shaft of the motor. And a joint that allows relative displacement of the motor and the load wheel in a substantially orthogonal direction. Further, a viscosity or damping function may be added to the elastic support structure of the motor.

  Thus, according to the wheel motor support structure of the present invention, the motor is elastically supported by the vehicle body side member or the suspension device, and the rotation shaft of the motor is substantially connected to the connection portion between the rotation shaft of the motor and the load wheel. By using a joint that allows relative displacement of the motor and the load wheel in the orthogonal direction, the motor and its elastic support structure exert a dynamic damper effect while improving the riding comfort while allowing the motor and the load wheel to be eccentric. To do.

Next, a first embodiment of the wheel motor support structure of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a side view of the wheel motor support structure of the present embodiment, and FIG. 2 is a plan view thereof. The suspension device of the present embodiment is a semi-trailing arm type suspension device in which a lower arm that supports a wheel extends obliquely rearward with respect to the vehicle width direction. Reference numeral 1 in the figure denotes a case for incorporating a motor, and the structure therein is clearly described as will be described later, as viewed in section AA in FIG. The case 1 is connected to the rear end portion of the semi-trailing arm 21 via a bush. Further, the case 1 itself constitutes a part of the suspension device and has, for example, a hub function. And the lower end part of the strut member 22 which consists of the shock absorber which has a damping function, and the coil spring which has a spring function is connected to this case 1 via the bush. The front end portion of the semi-trailing arm 21 and the upper end portion of the strut member 22 are both connected to the vehicle body side member. Reference numeral 20 in the figure denotes a pneumatic tire, reference numeral 2 denotes a road wheel, a braking rotor 3 is attached, and a central portion of the road wheel 2 is connected to an axle 4 that is a drive shaft. Yes.

  In the present embodiment, when the motor 5 is elastically supported in the case 1, a plurality of fluid mounts 6 are evenly (equally angled) interposed between the outer periphery of the motor 5 and the case 1. In this embodiment, the rotating shaft of the motor 5 and the axle 4 are connected by two universal joints (universal joints) 7. The universal joint 7 effectively transmits the torque of the motor 5 to the road wheel 2 while suppressing torque fluctuation to drive the wheel (in some cases, regenerative braking), and the motor 5 and the motor rotation shaft of the road wheel 2. And a joint structure that allows relative displacement in a substantially orthogonal direction, that is, allows eccentricity of both. In addition, the code | symbol 8 in a figure is a bearing.

  An example of the fluid mount 6 is shown in FIG. The fluid mount 6 is configured, for example, by forming a main fluid chamber 11 and a sub fluid chamber 12 in a main rubber 10 and enclosing a fluid therein. The main fluid chamber 11 is formed inside the main rubber 10. The auxiliary fluid chamber 12 is in contact with the air chamber 14 through a diaphragm 13. The main fluid chamber 11 and the sub-fluid chamber 12 are communicated with each other through a flow path 15 formed around the main rubber 10, and a damping effect is obtained by narrowing the flow path in the flow path 15. A generated orifice 16 is formed. The main rubber 10 itself has a rigidity capable of receiving the torque reaction force of the motor 5. That is, according to the fluid mount 6, the main rubber 10, the air chamber 14, and the diaphragm 13 constitute a spring, and the orifice 16 constitutes a damper. That is, the fluid mount 6 is an elastic support structure that elastically supports the motor 2 and is provided with a viscosity or damping function. And the dynamic damper is comprised by adding the mass (mass) of motor 5 itself to this.

  An example of the layout of the fluid mount 6 is shown in FIG. The solid lines are four on the outer periphery of the motor 5 and the broken lines are a total of eight fluid mounts 6 arranged equally on the outer periphery of the motor 5, respectively. FIG. 5 schematically shows the dynamic damper effect on the vibration of the load wheel 2 by the fluid mount 6 and the motor 5, but a plurality of fluid mounts 5 are evenly arranged on the outer periphery of the motor 5 as shown in FIG. If this is provided, the dynamic damper effect is exhibited not only in the vertical direction but also in all directions including the front-rear direction, and as a result, the ride comfort is improved against harshness.

FIG. 6 shows the attenuation state when the vibration frequency to the road wheel is variously changed. The smaller the gain (gain) as an evaluation index, the better the attenuation. As can be seen from the figure, according to the wheel motor support structure of the present embodiment, the vibration damping effect by the dynamic damper is greater than that of the conventional motor-equipped normal vehicle, and the riding comfort is excellent.
Further, since the output shaft of the motor 5 and the axle 4 are connected via the two universal joints 7, the motor torque can be transmitted while allowing the eccentricity between the load wheel 2 and the motor 5 as shown in FIG. It becomes possible.
Furthermore, by making the rigidity of the fluid mount 6 rigid enough to receive the reaction force of the motor 5, it is possible to prevent rotational torque and vibration of the motor.

FIG. 7 shows a second embodiment of the wheel motor support structure of the present invention. This embodiment is similar to the first embodiment of FIG. 2 and has many equivalent components. Therefore, the same components are denoted by the same reference numerals, and detailed description thereof is omitted. The structure of the suspension device is the same as that of the first embodiment shown in FIGS.
This embodiment is different from the first embodiment in that only one universal joint 7 is used to connect the output shaft of the motor 5 and the axle 4. In this way, if only one universal joint 7 is used to connect the output shaft of the motor 5 and the axle 4, the allowable eccentricity between the road wheel 2 and the motor 5 is slightly smaller than that in the first embodiment, The structure is simple and the cost can be reduced. Other functions and effects are the same as those of the first embodiment.

In the above embodiment, the motor is housed in the case. However, in the wheel motor support structure of the present invention, the motor does not necessarily have to be housed in the case.
In the above embodiment, the universal joint is used as the joint structure that allows relative displacement in the direction orthogonal to the motor rotation axis of the motor and the load wheel. However, the joint structure of the wheel motor support structure of the present invention is limited to this. For example, a constant velocity joint may be used as a joint structure that reliably transmits motor torque and allows relative displacement in a direction substantially orthogonal to the motor rotation shaft of the motor and load wheel.

  In the above embodiment, a fluid mount is used as a structure for elastically supporting the motor, and a damping function is intentionally added to the fluid mount. However, in the present invention, the motor is a mass and the elastic support structure is a spring. As long as the dynamic damper is configured, any elastic support structure may be used. In addition, since a general elastic body has a viscosity or a damping function, the vibration is damped to some extent even when the motor is mounted using, for example, the main body rubber.

It is a side view which shows 1st Embodiment of the wheel motor support structure of this invention. It is a cross-sectional view of the wheel motor support structure of FIG. It is a cross-sectional view which shows an example of the fluid mount used for the wheel motor support structure of FIG. It is explanatory drawing which shows the example of arrangement | positioning of the fluid mount of the wheel motor support structure of FIG. It is explanatory drawing of an effect | action of the wheel motor support structure of FIG. It is explanatory drawing of the effect of the wheel motor support structure of FIG. It is a longitudinal cross-sectional view which shows 2nd Embodiment of the wheel motor support structure of this invention.

Explanation of symbols

1 is a case 2 is a road wheel 3 is a rotor 4 is an axle 5 is a motor 6 is a fluid mount 7 is a universal joint 8 is a bearing 20 is a pneumatic tire 21 A trailing arm 22 is a strut member

Claims (6)

  A wheel motor support structure that directly drives the road wheel to rotate with the motor rotation shaft, elastically supports the motor on the vehicle body side member or suspension device, and at the connection portion between the motor rotation shaft and the road wheel. A wheel motor support structure using a joint that allows relative displacement of the motor and the load wheel in a direction substantially orthogonal to the rotation shaft of the motor.   The wheel motor support structure according to claim 1, wherein a viscosity or a damping function is added to an elastic support structure for a vehicle body side member or a suspension device of the motor.   The wheel motor support structure according to claim 1 or 2, wherein a fluid mount is used as an elastic support structure for the vehicle body side member or suspension device of the motor, and the outer periphery of the motor is uniformly supported by a plurality of fluid mounts. .   The wheel motor support structure according to claim 3, wherein the fluid mount has rigidity to receive a torque reaction force of the motor.   The wheel according to any one of claims 1 to 4, wherein at least one universal joint is used as a joint structure that allows relative displacement of the motor and the load wheel in a direction substantially orthogonal to the rotation axis of the motor. Motor support structure.   The wheel motor support structure according to claim 5, wherein two universal joints are used as a joint structure that allows relative displacement of the motor and the load wheel in a direction substantially orthogonal to the rotation shaft of the motor.

Images