EP2758259A1

EP2758259A1 - Wheel suspension device with wheel bearing support connected thereto in a steerable manner and with an integrated wheel drive motor

Info

Publication number: EP2758259A1
Application number: EP11760776.2A
Authority: EP
Inventors: Oswald Friedmann; Michael Kistler
Original assignee: Schaeffler Technologies AG and Co KG
Current assignee: Schaeffler Technologies AG and Co KG
Priority date: 2011-09-22
Filing date: 2011-09-22
Publication date: 2014-07-30
Also published as: CN103826883B; WO2013041141A1; CN103826883A

Abstract

The invention relates to a wheel suspension device comprising a wheel bearing support and a control arm element which can be pivoted about an inner hinge point and which is connected to the wheel bearing support via an outer hinge point such that the wheel bearing support can be moved in a vertical direction and can be pivoted about a substantially vertical steering axis in order to set required angles of lock. The wheel suspension device also comprises a wheel bearing device which is received in the wheel bearing support, a wheel hub which is mounted via the wheel bearing device, a wheel drive motor for generating a drive torque, and a driveshaft for transmitting the drive torque from the wheel drive motor into the region of the wheel bearing support. According to the invention, the wheel drive motor is coupled to the control arm element in a pivotal manner via a hinge device, and said coupling is produced such that the wheel drive motor can be pivoted about a substantially vertical motor pivot axis which extends in an intermediate region between the outer hinge point and the inner hinge point of the control arm element.

Description

Name of the invention

Wheel suspension with steered wheel bearing carrier and integrated wheel drive motor

description

Field of the invention

The invention relates to a motor vehicle wheel suspension device with a wheel bearing carrier guided steerable therein for setting wheel angles and a wheel drive motor integrated in the wheel suspension device, in particular of an electromechanical design.

From DE 31 36 305 A1 a drive axle for heavy motor vehicles is known in which in each case a countershaft transmission is arranged in the region of the respective wheel, which is coupled in each case via a propeller shaft to a differential gear. The drive axle comprises a brake arrangement formed by brake disks which sits in an intermediate region between the differential gear and the respective drive shaft. The braking torque generated by this brake assembly is thus applied to the input of the respective countershaft transmission. From FR 2 941 403 A1 a wheel suspension device is known, which likewise comprises a countershaft transmission integrated into the respective vehicle wheel, which is coupled via a propeller shaft to a vehicle-side drive train. Countershaft transmissions have hitherto been used predominantly in all-terrain vehicles or heavy-duty vehicles and offer the advantage that lower drive torques have to be guided via the wheel drive shafts. In addition to the field of off-highway and heavy-duty vehicles, gearboxes close to the gearbox are now also being considered for use in light, electromechanically operated motor vehicles considered mechanically driven motor vehicles in which the wheel drive is accomplished by near-wheel individual motors.

Object of the invention

The invention has for its object to provide a suspension device for an electromechanically operated with single-wheel motor vehicle, which is characterized over previous designs by improved mechanical performance.

Inventive solution

The aforementioned object is achieved according to the invention by a wheel suspension device, with:

a wheel bearing carrier,

a link element which is pivotable about an inner pivot point and is connected to the wheel bearing carrier via an outer pivot point, so that the wheel bearing carrier can be displaced in a vertical direction and is pivotable about a substantially vertical steering axis;

a wheel bearing device which is accommodated in the wheel bearing carrier,

a wheel hub which is mounted via the wheel bearing device,

- A wheel drive motor, to generate a drive torque, and

a drive shaft for transmitting the drive torque from the wheel drive motor into the area of the wheel bearing carrier,

- Wherein the Radantriebsmotor is pivotally coupled to the link element via a hinge means, and this coupling is accomplished such that the Radantriebsmotor is pivotable about a substantially vertical engine pivot axis extending in an intermediate region between the outer hinge point and the inner hinge point of the link element , This makes it possible in an advantageous manner to provide a suspension with integrated single wheel motor, in which the mass of the motor forms part of the unsprung masses and which allows large Radeinschlagwinkel. According to the invention, the motor is coupled to the steering of the wheel, so that no collision between the engine and the wheel, or a recorded in the wheel area transmission can occur.

When steering the wheel according to the invention, the motor is also rotated to an axis almost parallel to the steering axis. This can preferably be done easily via a handlebar. This prevents a collision between the motor housing and the gearbox housing, as well as between the cardan shaft and the motor housing.

The gear ratio between motor rotation angle and steering angle is approximately 2: 1 in the construction described in more detail below, but can also be chosen differently, e.g. taking into account the space requirements and the maximum steering angle.

The coupling with translation effect can also be done by another gearbox such as a gear transmission, a cable transmission and the like. The handlebar is preferred because it represents the cheaper solution. The inventive arrangement of the Radantriebsmotors can be used in particular in a suspension with McPherson architecture. The wheel drive motor is held in this case via a joint mechanism substantially perpendicular to the handlebars and swiveled synchronously in accordance with the Radeinschlag. The joint mechanism may in particular include a sliding joint, a ball joint, or an elastic element via which a corresponding engine mount is achieved. According to a particularly preferred embodiment of the invention, the lower link element is designed as a wishbone. The coupling of the link element with the wheel bearing carrier is preferably carried out via a ball joint pivoting of the wheel bearing carrier relative to the handlebar element to a pointing in Fahrzeuglängsnchtung horizontal axis, as well as a substantially vertical steering axle allows. The vehicle-side connection of the link element, in particular when the same is executed as a wishbone, preferably takes place via elastomer bushings which allow pivoting of the link element about a horizontal axis pointing essentially in the vehicle longitudinal direction.

The inventive concept is particularly suitable for Fahrzeugvorderradaufhängungen with double wishbones, and suspensions in McPherson type.

In particular, in the execution of the suspension in McPherson type, it is possible in an advantageous manner to guide the wheel drive motor in its upper region via an upper engine link assembly and support. This upper engine linkage assembly is preferably designed as a wishbone arrangement over which the motor housing can be supported vertically displaceable.

The synchronization of the pivotal movement of the wheel bearing carrier and the wheel drive motor is preferably carried out by the wheel drive motor and the wheel bearing carrier are coupled together via a link mechanism. This linkage mechanism may include, for example, a rigidly coupled to the wheel bearing carrier - short - encoder lever and a rigidly coupled to the Radantriebsmotorgehäuse - slightly longer - Mitnehmerhebel, these two levers are coupled together via a possibly bent connecting link. That connecting link is preferably coupled via ball joints with the encoder lever and the driving lever.

According to a particularly preferred embodiment of the invention, a reduction gear is integrated in the wheel bearing carrier, which is coupled via the drive shaft with the Radantriebsmotor. This reduction gear is designed according to a particular aspect of the present invention as a planetary gear. The change in Radeinschlages is preferably carried out in a conventional manner in which the wheel bearing carrier carries a steering arm and is coupled via this steering arm and a tie rod there with a steering gear.

During operation of the vehicle, braking torques can also be generated via the wheel drive motor in addition to wheel drive torques. It is also possible to provide a mechanical brake device in the region of the wheel drive motor via which, in particular, a parking brake function or even a conventional braking effect can be generated.

Brief description of the figures

Further details and features of the invention will become apparent from the following description taken in conjunction with the drawings. It shows:

Figure 1 is a perspective sketch of a suspension according to the invention with integrated electromechanical Radantriebsmotor which is pivotally supported on the lower arm and is under a steering operation stocky synchronously and in the same direction tracked;

FIGS. 2a, 2b

Sketches to illustrate the operation of the suspension according to the invention, once in the unloaded state and once in a compressed state;

FIGS. 3a, 3b

further sketches to further illustrate the operation of the suspension according to the invention, once in straight ahead position and once in the folded state. 1 shows an independent suspension device according to the invention with integrated Radeinzelantriebsmotor 5 is shown. The independent wheel suspension shown here by way of example is designed in particular for a light passenger car and serves to suspend and drive a right, steerable vehicle front wheel. The suspension for a left vehicle front wheel is of course constructed according to mirror symmetry and not illustrated here.

The wheel suspension device according to the invention comprises a Radlager- carrier 1, a lower link element 2 which is pivotable about an inner joint G3 and is connected via an outer joint G4 to the wheel bearing carrier 1, so that the wheel bearing carrier 1 in the vertical direction V displaced and a substantially vertical steering axis X is pivotable, to set the required Radeinschlagswinkel W. Furthermore, the wheel suspension device includes a not in this view not further recognizable, recorded in the wheel bearing support 1 wheel bearing and a wheel hub in turn mounted in this wheel hub.

The wheel suspension device furthermore comprises a wheel drive motor 5 for generating a drive torque, and a drive shaft 6 for transmitting the drive torque from the wheel drive motor 5 into the area of the wheel bearing carrier 1.

The wheel suspension device according to the invention is characterized in that the wheel drive motor 5 is pivotally coupled to the link element 2 via a hinge device G7, and this coupling is accomplished such that the wheel drive motor 5 is pivotable about a substantially vertical motor pivot axis XM located in an intermediate region extends between the outer hinge point G4 and the inner hinge point G3 of the link element 2.

The link element 2 is designed here as a wishbone and can thus support the wheel bearing carrier 1 longitudinally and transversely in the region of the joint G4 and lead in a vertical direction. The further support and guidance of the wheel bearing carrier 1 is achieved here by the suspension is designed as a McPherson suspension, ie the wheel bearing carrier 1 is guided translationally on a strut 8. The outer joint G4 is designed as a ball joint and allows pivoting of the wheel bearing carrier 1 relative to the lower arm 2 about the steering axis X and pivoting about a substantially horizontal axis in the context of compression and rebound of the wheel bearing carrier 1 in the strut eighth In addition to the connection to the lower arm 2 of the wheel drive motor 5 is also guided over an upper engine link assembly 9. This upper engine link assembly 9 is also designed as a wishbone arrangement and coupled via a joint G10 with the Radantriebsmotor 5. The wheel drive motor 5 is kinematically integrated into the wheel suspension device via the articulation points G7 and G10 in such a way that it can cushioned with the lower link 1 and can pivot the motor pivot axis XM defined by the pivot points G7, G10.

The wheel drive motor 5 and the wheel bearing carrier 1 are coupled to one another via a linkage mechanism. This link mechanism comprises a rigidly coupled to the wheel bearing carrier 1 encoder lever 1 1 and a rigidly coupled to the housing of the Radantriebsmotors 5 driving lever 12. These two levers 1 1, 12 are coupled via a connecting link 13 with each other.

In the wheel bearing carrier 1 is integrated a reduction gear. The drive shaft 6 couples an input of the reduction gear to the output of the wheel drive motor 5. The reduction gear is designed as a preferably two-stage planetary gear. The drive shaft 6 can be guided on the sun gear and the wheel-side output can be accomplished via the planetary wheel carrier. In the wheel bearing carrier, the ring gear is then fixed. In order to pivot the wheel bearing carrier in required angular positions of this may be provided with a steering arm 15 to which a tie rod 16 is connected in a known manner, the steering arm 15 coupled to a steering gear not shown here.

Figures 2a and 2b illustrate the operation of the suspension of the invention in a ground state (Figure 2a) and in a sprung state 2b. The wheel drive motor 5 is connected via the hinge point G7 to the lower arm 2 and additionally supported by the upper arm assembly 9. The wheel drive motor 5 can thus co-spring the lower link 2, wherein the stroke amplitude is reduced according to the lever ratios. The wheel drive motor 5 is pivotable about the motor pivot axis XM. The motor pivot axis XM and the steering axis X run in this embodiment to a common point P1. This point P1 is preferably located in the region in which the strut 8 is mounted on the body. The kinematic coupling of the housing of the Radantriebsmotors 5 with the wheel bearing carrier 1 via the handlebar 13 is preferably accomplished such that the Radantriebsmotor 5 is pivoted with a certain reduction, i. the wheel swivel angle is always greater than the engine swivel angle. As a result, gyroscopic effects of the motor 5, and the power requirement are reduced.

In Figures 3a and 3b, the operation of the suspension device according to the invention is further illustrated. As can be seen, the encoder lever 1 1 dimensioned shorter than the driving lever 12. As a result, as already mentioned above achieved that the wheel drive motor 1 and the rim 15 in synchronized synchronously pivot in the same direction. If, as outlined in FIG. 3b, the rim 15 is pivoted about the steering angle X about the steering angle W1, the drive motor 5 about the motor pivot axis XM becomes an adjustment angle W2 also swung in the same direction, wherein this adjusting angle W2 is smaller than the steering angle W1.

In this case, the drive shaft 6 assumes the oblique position indicated here for the drive motor 5 and for the wheel bearing carrier 1 or the planetary gear accommodated therein. Preferably, the connection areas of the drive shaft 6 to the drive motor 5 and the planetary gear are selected so that they are close to the axes XM and X respectively. This ensures that at most small changes in the distance by the drive shaft 6 must be compensated within the scope of a steering operation.

A motor vehicle equipped with the wheel suspension device according to the invention preferably comprises four wheel drive motors which are assigned to the respective vehicle wheel. Depending on the current vehicle operating state and the power requirement determined by the driver, these wheel drive motors can be controlled in such a way that I give the driver a driving characteristic which is perceived as suitable. Any reaction forces on the steering system caused by the wheel drive motors and in particular the coupling mechanism can be modified, in particular compensated, by actively influencing the steering force assistance behavior.

The wheel drive motor 5 and the inner flange area of the planetary gear can be coupled to each other via an elastomer bellows structure, so that the drive shaft rotates in a non-rotating elastomer housing. The link mechanism according to the invention with the links 1 1, 12, 13 is preferably located outside of this elastomer housing.

The wheel drive motor 5 is preferably designed as an internal rotor motor and is provided in its housing area with cooling rib structures via which the heat dissipation is assisted under the effect of the ambient air flowing through the rim 15.

Claims

claims

1 . Suspension system, with:

a wheel bearing carrier (1),

- A link element (2) which is pivotable about an inner hinge point (G3) and via an outer hinge point (G4) to the Radla gerträger (1) is connected, so that the wheel bearing carrier (1) displaceable in the vertical direction and a in the essential vertical steering axis (X) is pivotable, for setting required wheel bearing angle (W1),

a wheel bearing device which is accommodated in the wheel bearing carrier (1),

- A wheel drive motor (5), for generating a drive torque, and

- A drive shaft (6) for transmitting the drive torque from the wheel drive motor (5) in the region of the wheel bearing carrier (1),

- Wherein the wheel drive motor (5) with the link element (2) via a hinge device (G7) is pivotally coupled, and this coupling is accomplished such that the wheel drive motor (5) is pivotable about a substantially vertical motor pivot axis (XM), the extends in an intermediate region between the outer hinge point (G4) and the inner hinge point (G3) of the link element (2).

2. Wheel suspension device according to claim 1, characterized in that the link element (2) is designed as a wishbone.

3. Wheel suspension device according to claim 2, characterized in that the suspension is designed as a McPherson suspension.

4. Wheel suspension device according to at least one of claims 1 to 3, characterized in that the wheel drive motor (5) via an upper engine link assembly (9) is guided.

5. Suspension device according to claim 4, characterized in that the upper engine linkage assembly (9) is designed as a wishbone arrangement.

6. Wheel suspension device according to at least one of claims 1 to 5, characterized in that the wheel drive motor (5) and the wheel bearing carrier (1) are coupled together via a link mechanism.

7. Wheel suspension device according to at least one of claims 1 to 6, characterized in that the link mechanism comprises a rigidly with the Rad- bearing carrier (1) coupled encoder lever (1 1) and a rigidly coupled to the Radantriebsmotorgehäuse entrainment lever (12), and that this two levers (1 1, 12) via a connecting link (13) are coupled together.

8. Suspension device according to at least one of claims 1 to 7, characterized in that in the wheel bearing carrier (1) has a reduction gear is incorporated and that the drive shaft (6) an input of the reduction gear to the output of the Radantriebsmotors (5) coupled, wherein the reduction gear is designed as a planetary gear.

9. Wheel suspension device according to claim 8, characterized in that the wheel bearing carrier is provided with a steering arm and is coupled via this steering arm with a steering gear. Wheel suspension device, with:

a wheel bearing carrier (1),

- A wishbone element (2) which is pivotable about an inner hinge point (G3) and via an outer hinge point (G4) to the wheel bearing carrier (1) is connected, so that the wheel bearing carrier (1) displaceable in the vertical direction and a substantially vertical Steering axle (X) is pivotable, to set the required Radeinschlagwinkel (W1),

- A wheel drive motor (5), for generating a drive torque, and

- The wheel drive motor is mounted pivotably about a substantially vertical motor pivot axis (XM) and is coupled to the wheel bearing carrier (1) such that the wheel drive motor follows a pivotal movement of the wheel bearing carrier (1).