Patent Application
20210008939
The invention relates to a suspension for a wheel of an axle of a motor vehicle according to the preamble of claim 1.
The wheels of a motor vehicle are arranged on the vehicle body in a movable manner via the suspension. The suspension comprises particularly a wheel support to which a vehicle wheel is attached. With a steered axle, the wheel support has, depending on the axle principle, a certain number of links, which connect the wheel support to the vehicle body. At least one lower link, one upper link, and the tie rod are required for wheel control. The tie rod connects the wheel support to a steering gear, usually positioned transversely, which is used to transfer steering torques. However, this type of steered axle requires a lot of installation space.
There are also known designs in which a wheel support is connected to a steering actuator, which can turn the wheel support, in order to implement steering movements directly at the respective vehicle wheel.
For example, DE 102 44 140 A1 discloses an independent link suspension of a vehicle wheel, in which the wheel support is arranged over a pivot bearing. A link is connected to the vehicle body via a suspension strut and supports a steering actuator, which engages the wheel support via a steering arm and can thus rotate it on the link in order to implement steering movements of the vehicle wheel.
DE 10 2010 007 994 A1 discloses a suspension for a vehicle, in which the wheel support has two supporting elements. A first supporting element is arranged on the wheel side, and a vehicle wheel is rotatably mounted thereon. A second supporting element is arranged on the axle side and connected to the vehicle body by means of links. The axle-side and wheel-side supporting elements of the wheel support are coupled together via a universal joint. An actuator is connected between the two supporting elements, upon the actuation of said actuator the wheel-side supporting element can be adjusted as relates to the axle-side supporting element with the aid of drive motors in order to adjust the toe and/or camber angles.
The object upon which the invention is based is to refine a wheel support of a suspension for a wheel of an axle of a motor vehicle according to the type indicated in the preamble of claim 1 such that said wheel support has a simple design and requires minimal installation space.
This object is achieved by the characterizing features of claim 1 in conjunction with its preamble features.
The dependent claims form advantageous refinements of the invention.
In a known way and manner, the suspension of a motor vehicle comprises a wheel support mounted on the vehicle body via several links, said wheel support having a first, wheel-side supporting element, on which a vehicle wheel is rotatably mounted, as well as a second supporting element. The first supporting element can be rotated as relates to the second supporting element by means of a steering actuator arranged on the wheel support.
According to the invention, the first supporting element is connected to the vehicle body by means of an upper wishbone, and the second supporting element is connected to the vehicle body exclusively via a lower wishbone. As a flexible connecting piece between the wheel support and the body, the wishbones enable the freedom of movement of the wheel necessary for steering and absorb the forces acting horizontally. These forces are transferred to the vehicle body via the wishbones. The wishbones thereby contribute to the stable control of the vehicle. As a whole, the design of the suspension according to the invention has an advantageously low number of components and thereby requires little installation space.
According to one embodiment, the first supporting element is connected to the vehicle body by means of an upper wishbone, particularly a link rod. The link rod serves as a flexible connecting piece between the wheel support and the body. It connects the wheel support to the body via a ball joint. In doing so, it enables the freedom of movement of the wheel necessary for steering and absorbs the forces acting horizontally. It thereby contributes to the stable control of the vehicle. Due to its geometry, a link rod takes up limited installation space in an advantageous manner.
In a preferred embodiment, the second supporting element of the wheel support is connected to the vehicle body by means of a lower trapezoidal link. It serves as a flexible connecting piece between the wheel support and the body and is connected to the wheel support via two connection points and connected to the vehicle body via two further connection points. A trapezoidal link has a flat design and is broadly mounted on the vehicle body. In an advantageous manner, it can transfer, due to its wide design, forces acting horizontally and particularly also longitudinal forces to the body upon the acceleration of the motor vehicle. It thereby enables stable control of the vehicle.
Preferably, the first supporting element is mounted in a guide bushing of the second supporting element. The first supporting element can thereby be rotated as relates to the second supporting element in a simple manner and a desired steering angle can be adjusted via the first supporting element of the wheel support.
An alternative embodiment provides that the first supporting element is in the form of a guide bushing, in which the second supporting element is mounted. Thus, the first supporting element can be rotated as relates to the second supporting element, and a desired steering angle can be adjusted via the first supporting element of the wheel support.
Preferably, the second supporting element has a recess for a steering actuator. The steering actuator can be supported, in a manner beneficial to installation space for example, in a cup-shaped recess of the second supporting element. Because of the arrangement of the steering actuator on the second supporting element, it can transfer steering torques directly to the wheel support, and thus to the vehicle wheel. The arrangement of the steering actuator on the second supporting element is especially advantageous, because the steering torques provided by the steering actuator can be supported on the vehicle body via the trapezoidal link.
Preferably, the steering actuator has an electric motor as well as gearing, which may be formed particularly as a planetary gear unit. The electric motor transfers its force to the gearing. Its movements can be transferred directly to the wheel support due to the arrangement of the steering actuator on the wheel support. Thus, the required steering torque can be provided.
Preferably, the first supporting element is actively connected to the steering actuator such that it can cause a rotational movement of the first supporting element. For example, it is conceivable that the first supporting element is mounted in the second supporting element, wherein the first supporting element is designed as a output shaft of the gearing, and the second supporting element is designed as a guide bushing for the output shaft. The transfer of force from the gearing to the output shaft enables a rotation of the first supporting element as relates to the second supporting element. The steering torques provided by the steering actuator can thereby be transferred to the first supporting element, and thus to the vehicle wheel.
It is also conceivable that the second supporting element is designed as an output shaft of the gearing and is mounted in a guide bushing of the first supporting element. A positive-locking connection between the output shaft and the guide bushing ensures that the torque can be reliably transferred from the gearing to the first supporting element. Thus, the first supporting element can be rotated via the steering torques provided by the steering actuator, and a desired steering angle of the vehicle wheel can be adjusted.
In a preferred embodiment, exclusively the steering actuator executes the steering commands For example, a sensor can transmit the steering commands exclusively electrically to the steering actuator via a control unit, with said steering actuator executing the steering command. With this embodiment, there is no mechanical connection between the steering wheel and the steered wheels, as compared to conventional wheel guidance, which requires at least one lower link, one upper link, and a tie rod, wherein the tie rod connects the wheel support to a steering gear, usually positioned transversely, which serves to transfer the steering torques. In an advantageous manner, the suspension according to the invention has a lower number of components and thereby takes up little installation space, which has an advantageous effect on the packaging space.
Preferably, the suspension consists of three assemblies, comprising the upper wishbone, the lower trapezoidal link, as well as the two-part wheel support, which has a first and a second supporting element. Depending on the axle principle, conventional suspensions have up to five links on the wheel support, as well as a transverse steering gear, which is connected to the wheel support by means of a tie rod and is used to steer the axle. The suspension according to the invention has a lower number of components and thereby takes up little installation space, which has an advantageous effect on the packaging space.
Further advantages and application options of the present invention result from the following description in conjunction with the exemplary embodiments shown in the figures.
The following is shown:
An upper wishbone 20, which is formed as a link rod in this case, connects the first supporting element 12 to the body of the vehicle. The link rod 20 is connected to the first supporting element 12 by means of a ball joint 22. Thus, the vehicle wheel can move freely up and down and execute steering movements. The vehicle wheel transmits all of the wheel forces occurring to the link rod 20, which is connected to the vehicle body via a bearing 23.
The second supporting element 14 has a cylindrical guide bushing 24, in which a guide column, which is not shown here, of the first supporting element 12 is accommodated. In this manner, the first supporting element 12 is rotatably mounted as relates to the second supporting element 14. Alternatively, it is also conceivable that the first supporting element 12 is formed as a guide bushing 24, which accommodates a guide column assigned to the second supporting element 14, wherein the first supporting element 12 can be rotated as relates to the second supporting element 14.
In this case, the second supporting element 14 has a cup-shaped recess 30 for accommodating a steering actuator 31. The steering actuator 31 is attached directly to the second supporting element 14 of the wheel support 11 in a manner beneficial to the installation space and with a simple design and comprises an electric motor and gearing 32. The electric motor drives the gearing 32 in order to provide the required steering torque. The steering torques provided by the steering actuator 31 are supported on the vehicle body via a trapezoidal link 26.
The trapezoidal link 26 encompasses the cup-shaped recess 30 of the second supporting element 14. The second supporting element 14 is formed with two bearing pins 28, by means of which the trapezoidal link 26 is connected to the second supporting element 14. The trapezoidal link 26 is connected to the body of the vehicle by means of two joints 33. As clearly shown in
In this case, the guide column 36 of the first supporting element 12 is accommodated in a cylindrical guide bushing 24 of the second supporting element 14. The first supporting element 12 is thereby rotatably mounted in the second supporting element 14. The first supporting element 12 is actively connected to the gearing 32, particularly a planetary gear unit 32, of the steering actuator 31 accommodated in the second supporting element 14. In this manner, the rotation of the first supporting element 12 is enabled by means of the steering actuator 31.
The wheel support 11 of the axle according to the invention is shown from below in
The steering actuator 31 converts electrical signals of the steering movement into a mechanical movement of the planetary gear unit 32. The planetary gear unit 32 has a planetary gear 34, which is actively connected to the first supporting element 12 of the wheel support 11. In particular, the transfer of force takes place from the planetary gear unit 32 to the first supporting element 12, and thus to the vehicle wheel, via an output shaft 36 arranged on the planetary gear 34. In this case, the guide column 36 of the first supporting element 12 is designed as an output shaft 36 of the planetary gear unit 32. Thus, with the aid of the steering actuator 31, the first supporting element 12 can be rotated as relates to the second supporting element 14, and a desired steering angle of the vehicle wheel can be adjusted.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10 2018 202 208.9 | Feb 2018 | DE | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/EP2019/050813 | 1/14/2019 | WO | 00 |
