JP2001315534A - Motor mounting structure of wheel-in motor vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce inertia weight around a virtual kingpin shaft, and prevent an increase in steering force without deteriorating fuel consumption. SOLUTION: A wheel-in motor 5 is installed on an axle 3 for rotatably supporting a wheel 1 via speed reducer 7. A shock absorber 11 is arranged between the wheel-in motor 5 and a car body 9. The center of gravity G of a rotary part (such as the wheel 1, the axle 3 and the motor 5) for rotating at steering time is set on the virtual kingpin shaft 17 for connecting an upper mount 13 being a car body side installing part of the shock absorber 11 and a lower ball joint 15 being an axle side installing part of a suspension link for connecting the axle 3 and the car body under the wheel-in motor 5.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a motor mounting structure for a wheel-in motor vehicle having a motor mounted on an axle for rotatably supporting wheels and driving the wheels.

[0002]

2. Description of the Related Art Conventionally, as a motor mounting structure of a wheel-in motor vehicle, there is one described in, for example, JP-A-5-116545. This reduces the distance between the intersection of the virtual kingpin axis and the road surface and the intersection of the center line in the tire width direction and the road surface, that is, the increase in the steering force caused by the large scrub radius, by reducing the scrub radius and reducing the scrub radius. What you want to do.

[0003]

However, in the motor mounting structure of the conventional wheel-in-motor vehicle described above, the tires, the road wheels, and the axle / brake components are large outside the vehicle with respect to the virtual kingpin axis. As a result, the inertial weight around the virtual kingpin axis at the time of steering is large, and the steering may feel uncomfortable (the steering force is heavy). As a means for solving this, for example, there is a method by increasing the pump capacity of the hydraulic power steering, but there is a problem that the engine load increases and the fuel efficiency deteriorates.

Accordingly, an object of the present invention is to reduce the inertial weight around the imaginary kingpin and prevent an increase in steering force without deteriorating fuel efficiency.

[0005]

According to one aspect of the present invention, there is provided a motor having a motor mounted on an axle for rotatably supporting wheels and driving the wheels. A shock absorber mounted on the vehicle body side, which is attached between and can expand and contract in the axial direction,
Below the motor, the center of gravity of a rotating portion that rotates during steering around a virtual kingpin axis that connects an axle-side mounting portion of a suspension link connecting an axle and a vehicle body is disposed on the virtual kingpin axis. There is a configuration.

According to the motor mounting structure of a wheel-in-motor vehicle having such a configuration, at the time of steering, the rotating portion that rotates around the virtual kingpin axis rotates with its center of gravity positioned on the virtual kingpin axis.

According to a second aspect of the present invention, in the configuration of the first aspect, the center of gravity of the three components of the wheel, the axle, and the motor is arranged on a virtual kingpin axis.

According to the above configuration, at the time of steering, the three components including the wheel, the axle, and the motor that rotate about the virtual kingpin axis rotate with the center of gravity of the three components combined positioned on the virtual kingpin axis. .

A third aspect of the present invention is the configuration of the first aspect of the present invention, wherein the center of gravity of the motor is arranged on a virtual kingpin axis.

According to the above configuration, at the time of steering, the motor that rotates around the virtual kingpin axis rotates with its center of gravity positioned on the virtual kingpin axis.

According to a fourth aspect of the present invention, in the configuration of the first aspect of the present invention, a speed reducer for reducing and transmitting the rotation of the motor is disposed between the motor and the axle, and the wheel, the axle, the motor and the speed reducer are provided. The center of gravity of the four components is arranged on the virtual kingpin axis.

According to the above configuration, at the time of steering, the wheels, axles, motors, and reduction gears that rotate about the virtual kingpin axis rotate in a state where the center of gravity of the four components is located on the virtual kingpin axis.

According to a fifth aspect of the present invention, in the configuration of the first aspect of the present invention, a speed reducer for reducing and transmitting the rotation of the motor is disposed between the motor and the axle, and the two components of the motor and the speed reducer are combined. The center of gravity is arranged on a virtual kingpin axis.

According to the above configuration, at the time of steering, the motor and the speed reducer that rotate about the virtual kingpin axis are:
The center of gravity of the two components rotates on the virtual kingpin axis.

According to a sixth aspect of the present invention, in the configuration of the fourth or fifth aspect, the speed reducer comprises a planetary gear mechanism having a sun gear and a planetary gear, and rotates coaxially with an output shaft of the planetary gear mechanism. A drive gear meshing with the output gear is provided so as to be coaxially rotatable about the rotation center axis of the wheel at a position below the output gear.

According to the above configuration, the planetary gear mechanism and the motor are arranged above the driving gear coaxial with the rotation center axis of the wheel, and the space below the motor is increased.

[0017]

According to the first aspect of the present invention, since the center of gravity of the rotating portion that rotates about the virtual kingpin axis during steering is arranged on the virtual kingpin axis, fuel consumption is deteriorated due to an increase in engine load. Without inviting, the inertial weight around the virtual kingpin axis is reduced, and the steering force can be reduced.

According to the second aspect of the present invention, since the center of gravity of the three components of the wheel, the axle, and the motor is arranged on the virtual kingpin axis, the wheel, axle, and motor that rotate around the virtual kingpin axis during steering are provided. , Part 3
The center of gravity of the components is rotated with the center of gravity positioned on the virtual kingpin axis, and the inertial weight around the virtual kingpin axis can be reduced.

According to the third aspect of the present invention, since the center of gravity of the motor is disposed on the virtual kingpin axis, the motor that rotates about the virtual kingpin axis during steering has its center of gravity positioned on the virtual kingpin axis. To reduce the inertial weight around the virtual kingpin axis.

According to the fourth aspect of the present invention, a speed reducer for reducing and transmitting the rotation of the motor is arranged between the motor and the axle, and the center of gravity of the wheel, the axle, the motor and the speed reducer is combined. , Placed on the virtual kingpin axis,
A wheel that rotates about a virtual kingpin axis during steering,
The axle, the motor, and the speed reducer rotate while the center of gravity of the four components is located on the virtual kingpin axis, and the inertial weight around the virtual kingpin axis can be reduced.

According to the fifth aspect of the present invention, a speed reducer for reducing and transmitting the rotation of the motor is disposed between the motor and the axle.
Since it is arranged on the virtual kingpin axis, the motor and reducer that rotate around the virtual kingpin axis during steering are
The center of gravity of the two components is rotated with the center of gravity positioned on the virtual kingpin axis, and the inertial weight around the virtual kingpin axis can be reduced.

According to the sixth aspect of the present invention, the speed reducer is a planetary gear mechanism having a sun gear and a planetary gear, and the drive gear meshing with the output gear that rotates coaxially with the output shaft of the planetary gear mechanism outputs the output gear. Since it is provided so as to be coaxially rotatable with respect to the rotation center axis of the wheel at a position below the gear, the planetary gear mechanism and the motor are arranged above the drive gear coaxial with the rotation center axis of the wheel, and the space below the motor is reduced. This increases the degree of freedom in motor design.

[0023]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a basic structural diagram of a motor mounting structure of a wheel-in motor vehicle showing an embodiment of the present invention. Axle 3 that rotatably supports wheels 1 at the front of the vehicle
Is provided with a brake 4 and a motor 5 for rotationally driving the wheels 1 is mounted via a speed reducer 7 that reduces the driving force and transmits the driving force to the wheels 1.

A shock absorber 11 is arranged between the motor 5 and the vehicle body 9. Shock absorber 1
Reference numeral 17 connects an upper mount 13 serving as a vehicle-body-side attachment portion to the vehicle body 9 of the first vehicle 9 and a lower ball joint 15 serving as an axle-side attachment portion attached to the axle 3.
Is a suspension virtual kingpin axis (hereinafter simply referred to as a virtual kingpin axis).

When the center of gravity of the rotating part at the time of steering is located on the suspension virtual kingpin axis 17 described above, the moment of inertia is zero, but when the center of gravity is offset from the virtual kingpin axis 17, the moment of steering is reduced. The moment of inertia occurs, the steering force increases,
Give the driver a sense of discomfort.

The rotating parts described above are the wheel 1, axle 3, motor 5, reduction gear 7, and shock absorber 11. In this case, the center of gravity G of the five parts is combined with the virtual kingpin shaft 17 Set above. This prevents an increase in the total moment of inertia around the virtual kingpin axis 17 when steering the steering wheel, reduces the steering force, and improves the steering feeling. This eliminates the need to increase the pumping capacity of the power steering, and therefore does not cause a decrease in fuel efficiency due to an increase in the engine load.

In the above-described embodiment, all five parts of the wheel 1, the axle 3, the motor 5, the speed reducer 7, and the shock absorber 11 are considered as the rotating part, but any one or a plurality of parts are considered. Even if the center of gravity of the combined parts is set on the virtual kingpin shaft 17, the total moment of inertia around the virtual kingpin shaft 17 can be prevented without increasing the pumping capability of the power steering. As described above, the design becomes easy by reducing the number of components considering the position of the center of gravity as the rotating portion.

For example, the center of gravity of only the motor 5 may be set on the virtual kingpin shaft 17, and the entire center of gravity of the wheel 1, the axle 3 and the motor 5 may be set on the virtual kingpin shaft 17. Alternatively, the overall center of gravity of the two parts of the motor 5 and the speed reducer 7 may be set on the virtual kingpin shaft 17.

FIG. 2 shows the detailed structure of FIG. The tire 19 is mounted on the road wheel 21 as the wheel 1, and the axle 3 includes a brake disc 23, a hub 25,
It comprises a spindle 27 and an axle bearing 29. Brake disc 23 and hub 25 are bolted
The nut 31 is fixed to the load wheel 21, and the spindle 27 is fixed to the hub 25 by a nut 32.

In the motor 5, a motor shaft 35 to which a rotor 33 is fixed is rotatably provided on a motor housing 39 via a pair of motor bearings 37, and a stator 41 is mounted on an inner surface of the motor housing 39. . A rotation speed sensor 43 for detecting the rotation speed of the motor 5 is provided outside the motor housing 39 at the left end of the motor shaft 35 in the drawing.

The lower end of the shock absorber 11 whose upper end is connected to the vehicle body 9 is a sectional view taken along the line A--A in FIG.
As shown in FIG. 4 which is a plan view of FIG. 3, a mounting bracket 45 provided at a lower portion of the shock absorber 11 is fastened to a thick portion 39 a of the motor housing 39 by a bolt 47, and is attached to the motor housing 39. Fixed.

In FIG. 3, the internal stator 41 and the like are omitted, and in FIG. 2, the mounting bracket 45 and the thick portion 39a in FIG. 3 are omitted.

The speed reducer 7 is constituted by a planetary gear mechanism having a sun gear 49 fixed to the motor shaft 35 at a portion of the motor housing 39 projecting rightward in the figure, and a plurality of planetary gears 51 meshing with the sun gear 49. These are accommodated in the reduction gear housing 53. The reduction gear housing 53 has a ring gear 55 with which a plurality of planetary gears 51 mesh with each other mounted on an inner peripheral surface thereof, and is fixed to the motor housing 39 by bolts (not shown).
Carrier 57 for interconnecting a plurality of planetary gears 51
Is connected to the spindle 27, and the rotational power from the speed reducer 7 is transmitted to the axle 3 and the wheels 1.

The motor housing 39 and the reduction gear housing 53 are formed separately from each other. Therefore, for example, the motor housing 39 which requires heat radiation is made of aluminum, while the speed reduction which requires strength is used. Optimum design becomes possible by forming the machine housing 53 from iron or the like.

The lower ball joint 15 here is rotatably mounted on a mounting portion 59 protruding from a lower portion of the motor housing 39 on the side of the speed reducer 7, and serves as a suspension link having one end connected to the lower ball joint 15. The other end of the lower link 61 is rotatably connected to the vehicle body 13 side.

A straight line connecting the upper mount 13 and the lower ball joint 15 is a virtual kingpin shaft 17,
The tire 19 is steered around the virtual kingpin axis 17 as a rotation axis.

Next, a method of setting the center of gravity G of the rotating portion on the virtual kingpin shaft 17 will be described.

The components constituting the rotating part, for example, the shock absorber 11, are designed in accordance with the weight and required performance of the vehicle. The same applies to the motor 5, the speed reducer 7, the axle 3 and the wheels 1.

In the design of the motor 5, the output: P, the motor diameter: φD, and the motor length (width): L
And the following relationship.

P∝DXL That is, the motor output (P) is
It is proportional to the product of the motor diameter: φD and the motor length: L.

By using this relationship, it is possible to design a small-diameter long motor or a large-diameter short motor even with the same output motor. This means that the position of the center of gravity of the motor 5 is variable even if the motors have the same output depending on the motor design method.

FIG. 5 shows an example of changing the position of the center of gravity depending on the shape of the motor. According to this, when the center of gravity G of the rotating portion around the virtual kingpin axis 17 is inside the vehicle (left side in FIG. 5) with respect to the virtual kingpin axis 17, the large-diameter and short-shaped motor 5a ( Assuming that the center of gravity of the motor is Ga),
The center of gravity Ga is changed to the outside of the vehicle and the virtual kingpin shaft 17
Is set to a position closer to. On the other hand, the center of gravity G of the rotating portion around the virtual kingpin axis 17 is
Is outside the vehicle (right side in FIG. 5),
Motor 5b with small diameter and long shape (motor center of gravity Gb)
Then, the center of gravity Ga is changed to the inside of the vehicle, and is set to a position closer to the virtual kingpin shaft 17.

The strut, which is a component of the shock absorber 11, is changed in length according to the shape of the motor 5 to handle the strut.

FIG. 6 shows the data of the experimental results of the frequency response of the steering force in comparison between a vehicle equipped with a wheel-in motor (solid line) and a vehicle equipped with no wheel-in motor. In the vehicle with the wheel-in motor, the center of gravity of the rotating part is offset with respect to the virtual kingpin axis (the center of gravity of the rotating part does not match the virtual kingpin axis).

According to this, a vehicle equipped with a wheel-in motor has a larger steering force, especially at around 1 Hz, than a vehicle equipped with no wheel-in motor, which deteriorates the steering feeling. That is, virtual kingpin axis 1
If the position of the center of gravity of the rotating part is made to coincide with that of 7, it means that an increase in the steering force is avoided.

FIG. 7 shows another embodiment of the present invention. In this embodiment, an output gear 65 is attached to an output shaft 63 of a planetary gear mechanism in the speed reducer 7, and a drive gear 67 meshing with the output gear 65 is connected to a spindle 27 serving as a rotation center axis of the wheel 1. Is attached at a position below the lower gear to constitute the speed reducer 7. Also,
The output shaft 63 is rotatably supported on the reduction gear housing 53 by a bearing 69 on the side opposite to the side connected to the carrier 57, and the carrier 57 is connected to the planetary gear 51.
And the left carrier 57 is attached to the bearing 71
And is rotatably supported by the motor housing 39.

The lower ball joint 1 of the lower link 61
Reference numeral 5 is attached to a mounting bracket 73 provided at a lower portion of the reduction gear housing 53.

In the embodiment shown in FIG. 7, the motor 5 and the planetary gear mechanism can be arranged above the vehicle body as compared with the embodiment shown in FIG. 2, so that the space S between the motor 5 and the lower link 61 is increased. Therefore, the degree of freedom in designing the motor 5 (the degree of freedom in setting the center of gravity G) is increased.

In FIG. 7, the lower link 61 shows the normal state of the shock absorber 11 by a solid line and the bound state by a two-dot chain line. Even in the bound state, the motor 5 is connected between the lower link 61 and the lower link 61. It can be seen that a relatively large clearance has been obtained.

In each of the above embodiments, the structure of the motor 5 is described as an electric motor. However, the same effect can be obtained by using a hydraulic motor. Further, in each of the above embodiments, the shock absorber 11 has been described in the form of a strut. However, the shock absorber 11 may have another type as long as it has a kingpin axis (including a virtual kingpin axis).

[Brief description of the drawings]

FIG. 1 is a basic structural diagram of a motor mounting structure of a wheel-in motor vehicle showing an embodiment of the present invention.

FIG. 2 is a detailed structural diagram of FIG. 1;

FIG. 3 is a sectional view taken along line AA of FIG. 2;

FIG. 4 is a plan view of FIG. 3;

FIG. 5 is an explanatory diagram showing an example of changing the position of the center of gravity depending on the shape of a motor.

FIG. 6 is an explanatory diagram showing data of results of a frequency response experiment of a steering force, which are compared between a vehicle equipped with a wheel-in motor and a vehicle not equipped with a wheel-in motor.

FIG. 7 is a detailed structural view showing another embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Wheel (rotating part) 3 Axle (rotating part) 5 Wheel-in motor (rotating part) 7 Reduction gear (rotating part) 9 Body 11 Shock absorber 13 Upper mount (body attaching part) 15 Lower ball joint (axle side attaching part) 17) Suspension virtual kingpin axis (virtual kingpin axis) 27 Spindle (wheel rotation center axis) 49 Sun gear 51 Planetary gear 61 Lower link (suspension link) 63 Output shaft 65 Output gear 67 Drive gear

Claims (6)

[Claims] 1. A vehicle-body-side mounting portion of a shock absorber that is mounted between an axle and a vehicle body and that is mounted on an axle that rotatably supports the wheel and that drives the wheels, and that is mounted between the axle and the vehicle body. Under the motor, the center of gravity of a rotating part that rotates during steering around a virtual kingpin axis connecting an axle-side mounting portion of a suspension link connecting an axle and a vehicle body,
A motor mounting structure for a wheel-in motor vehicle, wherein the motor mounting structure is arranged on the virtual kingpin axis. 2. A motor mounting structure for a wheel-in motor vehicle according to claim 1, wherein the center of gravity of the three components of the wheel, the axle and the motor is arranged on a virtual kingpin axis. 3. The motor mounting structure for a wheel-in motor vehicle according to claim 1, wherein the center of gravity of the motor is arranged on a virtual kingpin axis. 4. A reducer for reducing and transmitting the rotation of the motor is disposed between the motor and the axle, and the center of gravity of the four parts of the wheel, the axle, the motor and the reducer is disposed on the virtual kingpin axis. The motor mounting structure of a wheel-in-motor vehicle according to claim 1, wherein: 5. A reduction gear for reducing and transmitting the rotation of the motor between the motor and the axle, and a center of gravity of two parts of the motor and the reduction gear is arranged on a virtual kingpin axis. The motor mounting structure of a wheel-in motor vehicle according to claim 1, wherein 6. The reduction gear is constituted by a planetary gear mechanism having a sun gear and a planetary gear, and a drive gear meshing with an output gear that rotates coaxially with an output shaft of the planetary gear mechanism is provided at a position below the output gear. 6. The wheel according to claim 4, wherein the wheel is provided so as to be coaxially rotatable about a rotation center axis thereof.
Motor mounting structure of the described wheel-in motor vehicle.